Product Citations and Abstracts

Histological examination of oyster gonads from an area naturally exposed to prolonged periods of fresh water, when compared to oyster gonads from an adjacent, unexposed area, showed: 1. Gametogenesis was inhibited in 90% of the surviving population until salinity levels rose above 6 parts per thousand. 2. Following the salinity increase, oysters rapidly improved in condition but required from three to four months to attain the same final level of gonad activity as the unaffected group. 3. Marked variation and suppression of gonad activity in the exposed oysters is attributed to variations in food availability, rather than to direct inhibition of sexual activity by less saline water. 4. Sex ratios and extent of intersexuality in the population sampled, as well as details of the gametogenic cycle, agree for the most part with published observations on Ostrea virginica in other parts of its geographical range.

Butler, Philip A. 1945. Investigation of Oyster Producing Areas in Louisiana and Mississippi Damaged by Flood Waters in 1945. In: U.S. Fish Wildl. Serv. Spec. Sci. Rep. Fish. 8. 29 p. (ERL,GB 002A).

The dramatic floods in Mississippi Sound in 1945 and the less obvious but equally disastrous floodings of the past four years focus attention on the seasonal threat which excess fresh water imposes on the oyster community.

Butler, Philip A. and James B. Engle. 1950. 1950 Opening of the Bonnet Carre Spillway: Its Effect on Oysters. In: U.S. Fish Wildl. Serv. Spec. Sci. Rep. Fish. 14. 10 p. (ERL,GB 003).

Studies made on the condition of oyster reefs and the waters of the west end of Mississippi Sound during the past 18 months, as well as analyses of data on the amount of water discharge from the Pearl and Mississippi Rivers during the past 10 years, demonstrated the susceptibility of this area to the danger of excessive fresh water in the past decade. The discharge for the Pearl River alone during the past three out of four years has been sufficient to cause severe oyster mortalities. The unusually heavy precipitation in the Mississippi Basin during the winter months of 1949-1950 made it reasonable to assume that there would be unusually high river stages this spring. It was probable that fresh water from the Pearl River would again cause oyster mortalities and there was the strong possibility that the Bonnet Carre Spillway would have to be opened. For these reasons, I recommended to the Mississippi Seafoods Commission, while attending a meeting of that body on January 20, that they declare the oyster reefs of Mississippi, then closed, open for public fishing so that marketable oysters could be removed prior to the advent of the flood waters. This recommendation was followed only in part. The oyster reefs were opened for a few days and not many oysters were harvested. This was primarily because the oysters were not in prime condition and the fishermen were unwilling to harvest them. On February 9, the Corps of Engineers, U.S. Army announced that the Bonnet Carre Spillway was to be opened and arrangements were made immediately with the Mississippi Seafoods Commission for the use of their boats and personnel to conduct surveys of this area. The initial survey of the areas involved was made on February 10-11 to determine the condition of the oyster reefs and the water quality before the Mississippi River waters had time to flow into the area. On this survey it was found that the water in much of the region was already too fresh for the normal growth of oysters. A telegram was sent to the Chairman of the Mississippi Seafoods Commission on February 13 advising him of these conditions and recommending the emergency opening of the entire area for harvesting of the marketable oysters present. The Commission declared a state of emergency and opened the oyster reefs to fishing on February 15. Since that time the marketable oysters have been harvested for the most part, and the State is now engaged in an extensive program of removing the seed oysters (less than 3' in length) from these reefs to more easterly locations where they are not likely to be seriously affected by the flood waters.

Butler, Philip A. 1951. Erosion and the Littoral Benthos. Shore and Beach. 19:8-11. (ERL,GB 004).

This review of the relationships between shore erosion and our commercial fisheries is necessarily brief and our knowledge of the subject is far from complete. Unfortunately, examples of economic loss to our fisheries from shore erosion are almost endless. It is time to stop and ask ourselves, "What can we do about it?" We have some partial answers. We are fortunate in having many interested agencies that are doing their utmost in tackling this problem. However, I believe that we can hope to stimulate sufficient interest to control this destructive force of nature effectively only when the general public is fully aware of the economic seriousness of the effects that shore erosion may have on our fisheries.

Butler, Philip A. 1951. Research and the Oyster Industry. Southern Fisherman, 1951 Annual Review Number. 11:118-121. (ERL,GB 006).

During the past year the Fish and Wildlife Service Laboratory at Pensacola, Fla., has been investigating the problem of successful propagation of young oysters and trying to discover the factors which control desirable qualities of the mature oyster. To achieve these goals it is necessary, first, to raise the offspring resulting from a single male and female oyster and, second, to determine whether these young oysters have any striking familial tendencies or hereditary pattern. It is necessary for us to discover whether the various differences which we see in oysters result from the environment in which the oysters grow. Briefly, if an oyster grows very fast and has a well shaped shell, we want to know whether this resulted from the fact that its parents were like this or from the fact that it lived in a place where there was plenty of food available.

Butler, Philip A. 1952. Effect of Floodwaters on Oysters in Mississippi Sound in 1950. In: U.S. Fish Wildl. Serv. Res. Rep. 31. 20 p. (ERL,GB 007).

The results of these surveys agree substantially with the findings of 1948-49 and emphasize my earlier conclusion that the waters of the extreme western end of Mississippi Sound are marginal with respect to oyster culture. State of Louisiana biologists reached this same conclusion in 1950 when they reported that "this [adverse environment for oysters in west end of Mississippi Sound] is far outweighed by the benefits to those reefs in the southern region of the 'Louisiana Marsh'." The causal relationship of long-continued low salinities in Mississippi Sound to oyster mortalities is apparent. It is equally clear that such low salinities are the result of excessive precipitation either locally, in the sound area, in the Pearl River basin, or at some more distant point in the Mississippi River basin. Salinity levels harmful to oysters occur only when excessive amounts of water from two or more sources enter the area in conjunction. This entirely natural sequence of events may in summation cause disaster to the oyster population. It is illogical to blame any one item in the sequence, as the Bonnet Carre spillway through which part of the water may flow, for the resulting oyster mortalities.

Butler, Philip A. 1952. Shell Growth Versus Meat Yield in the Oyster C. virginica. Proc. Natl. Shellfish. Assoc. 43:157-162. (ERL,GB 008).

The ratio of total volume to shell volume appears to possess certain advantages in estimating growth and meat yielding potential of oysters as compared to the customary dimensional measurements. An evaluation of the growth of oysters from various areas on the basis of available data, indicates that from both the biological and commercial point of view, oyster growth is greatest in the Chesapeake Bay area and rate of growth declines progressively in warmer and colder environments. I believe that a survey of oyster producing areas using the total volume : shell volume (ratio) will substantiate my estimate of the growth differential in the different geographical regions.

Butler, Philip A. 1952. Seasonal Growth of Oysters (C. virginica) in Florida. Proc. Natl. Shellfish. Assoc. 43:188-191. (ERL,GB 009).

The pattern of growth in the commercial oyster is of fundamental importance to the grower because of its bearing on meat production. Environments noted for rapid increases in shell length, for example, may be of inferior value commercially unless such length increases are accompanied by corresponding volume increases. Some of the environmental factors known to affect growth patterns are: population density, type of cultch and substratum, density of commensal organisms, food supply, temperature and salinity. Despite the variety and complex ineractions of these several factors, typical growth patterns are usually quite well defined in local environments. Knowledge of these patterns is helpful to the biologist as well as to the commercial producer. The material presented here summarizes observations on the growth of individually identified oysters at Pensacola during the past three and a half years. Data are based only on oysters surviving at the end of the experimental periods indicated. In only one instance, 3-year old oysters, are there less than 50 specimens in the group; in others, the number of individuals varied from 60 to 200. Variations in the amount of growth in successive years and in adjacent but slightly dissimilar environments may obscure the basic pattern. Annual increases may vary, too, because of individual qualities in the oysters. For these reasons, all data are presented as percentage increases during stated time intervals; total annual increase is considered as 100 percent.

Butler, Philip A. 1953. Importance of Local Environment in Oyster Growth. In: Proc. Gulf Caribb. Fish. Inst., 5th Annual Session, Nov., 1952, Miami Beach, FL. University of Miami, Gulf and Caribbean Fisheries Institute, Coral Gables, FL. Pp. 99-106. (ERL,GB 010).

Cultivation of the oyster, Crassostrea virginica, Gmelin, has always been dependent to some degree on the transplanting of young oysters from so-called seed areas to growing grounds. In recent decades, however, the planter has had to go progressively farther afield for his source of seed and the scarcity of seed oysters in many producing areas is a problem of increasing concern. The transportation costs involved in these operations make it imperative that the imported stock survive and grow at better than average rates. Oysters are readily transplanted many thousands of miles from the area in which they set, but stocks from some areas have been found to grow better than others. It has been shown too, as in the case of the eastern oyster transplanted to the Pacific coast, that oysters, while growing well in a new environment may fail to reproduce normally. For these and other reasons, it has become desirable, if not imperative, that the biologist study growth and mortality rates in as many different imported stocks as possible so that the best of these may be recommended to the commercial planter. Stocks of oysters from the Pensacola area, where there is an abundant set, have been sent to several different geographical regions to develop information on this problem. In cooperation with Mr. Francis Beaven of the Chesapeake Biological Laboratory at Solomons Island, Maryland, reciprocal plantings of native oysters have been made. This paper summarizes observations on Chesapeake Bay oysters in Florida and compares their growth with that of Florida native stock.

Butler, Philip A. 1953. Oyster Predator Problem. Southern Fisherman. 13:35-58. (ERL,GB 011).

How much does the Gulf oyster suffer from predators? What is the dollar loss to the oyster growers and dealers? These are questions we can not answer yet, but the industry and research agencies agree that the loss is far greater than casual inspection might indicate. What is a predator? The conch or oyster drill, Thais, is a typical example. In one night, an average size drill can eat more than fifty tiny oysters. On a snail-infested roof, the entire summer's set of oysters can be killed in a few weeks by this snail; what might in a few years have been a fine commercial harvest can be destroyed before the oysters are even large enough to be noticed. The drill is not the only predator, however. There are many animals which feed on oysters, and still others which should be grouped with the predators although they do not actually feed on them, since they lower oyster quality and thus reduce the growers' income. A listing of the different forms known or presumed to cause oyster damage is formidable. Fortunately, they are not all equally destructive or prevalent. I have classified them according to the types of damage they inflict.

Butler, Philip A. 1953. Oyster Growth as Affected by Latitudinal Temperature Gradients. U.S. Fish Wildl. Serv. Comm. Fish. Rev. 15(6):7-12. (ERL,GB 012).

Summary: (1) Field and experimental observations indicate that volume rather than the customary length measurments provide a more critical evaluation of growth in the oyster. (2) The ratio of total oyster volume to shell volume provides a useful single index for estimating the meat-yielding potential of an oyster population when continuing observations are impractical. (3) Oyster growth varies geographically, responding to differences in the latitudinal temperature gradient. (4) Oysters in the latitude of Chesapeake Bay tend to grow faster and produce more meat in unit time than oysters growing north or south of this region.

Butler, Philip A. 1953. Southern Oyster Drill. Proc. Natl. Shellfish. Assoc. 44:67-75. (ERL,GB 013).

The carnivorous gastropod, Thais, known locally as the oyster drill or conch, is probably the most destructive single agent affecting the oyster industry of the Gulf States. Incredible numbers of them exist in the estuaries and coastal bays. They are found primarily on the oyster reefs but are not restricted to any particular bottom type or water depth. They frequent the mean low tide line on rocky shores and are caught in shrimp trawls 15 miles at sea in sixty feet of water. Although sensitive to salinity levels of the water they occur naturally in the wide range from 15 to 35 ppt. and can withstand entirely fresh water for short periods. They show no reaction to changing pH levels within the normal range and they survive, experimentally at least, at oxygen levels too low to support most other marine life. Thais is a very successful animal, biologically speaking, and there is evidence that it is continually extending its range. The occurrence of its shells mixed with oysters in the buried reefs shows that it has been here for thousands of years as a predator in the oyster community. References to the drill appear in the literature almost exclusively in connection with oyster reef surveys. Investigators in the early 1900's, including Moore, Pope, Danglade, and Churchill, were interested primarily in the incidence of the snail and published few facts concerning its biology. Some of their comments were quite erroneous, as pointed out by Burkenroad in 1931, whose paper is one of the few concerned primarily with the biology of this snail. St. Amant's master's thesis on the biology of Thais is the most comprehensive study we have, but unfortunately this paper has been published only in abstract. Dr. St. Amant, who is now with the Department of Wildlife and Fisheries in Louisana, made his field obervations in Barataria Bay in the years 1936 and 1937. His very comprehensive study was hampered by the lack of facilities for maintaining snails under laboratory conditions. The material I am presenting now is drawn from observations made at Pensacola and other Gulf areas in the past five years. Some of this information is new, and many of the details correct or extend our published knowledge of the snail.

Butler, Philip A. 1954. Selective Setting of Oyster Larvae on Artificial Clutch. Proc. Natl. Shellfish. Assoc. 45:95-105. (ERL,GB 014).

In summarizing this work, it appears that in this area the movement of mature larvae is governed almost entirely by the laws of chance and gravity. The only selectivity larvae show in setting results from their avoiding silt or other organisms and they will be found on the first clean surface they can reach regardless of its position in the water. It should be noted that these data refer to the incidence of setting and not spat survival. In some areas, factors causing early mortalities operate at certain levels or positions. This condition may produce an erroneous picture of the original location of the spatfall.

Butler, Philip A. 1954. Summary of Our Knowledge of the Oyster in the Gulf of Mexico. U.S. Fish Wildl. Serv. Fish. Bull. 55(89):479-489. (ERL,GB 015).

The ecology of the oyster in the Gulf of Mexico parallels, in many respects, conditions found along the Atlantic seaboard. Where significant biological differences exist between the two areas, they are due primarily to the higher temperature levels of the Gulf environment. The biological and economic problems facing the industry here have their counterpart in other oyster producing areas. The industry in the South can include among its distinctive advantages an unlimited area for the expansion of cultivated grounds and a seemingly inexhaustible supply of seed oysters.

Butler, Philip A. 1954. Methods for Controlling Southern Oyster Drill. Atlantic Fisherman. 35:17-35. (ERL,GB 016).

The oyster drill or conch is probably the most destructive single agent affecting the oyster industry of the Gulf States. Incredible numbers of them exist in the estuaries and coastal bays. They are found primarily on the oyster reefs, but are not restricted to any particular bottom type or water depth. They frequent the mean low tide line on rocky shores and are caught in shrimp trawls 15 miles at sea in 60' water. Although sensitive to salinity levels of the water they occur naturally in the wide range from 15 to 35 ppt., and can withstand entirely fresh water for short periods. The oyster drill is a very successful animal, biologically speaking, and there is evidence that it is continually extending its range. The occurance of its shells mixed with oysters in the buried reefs shows that it has been present for thousands of years as a predator in the oyster community. The sensory keenness of the oyster drill or snail plus its fondness for young oysters makes it possible to place wire bags baited with spat on the reefs and attract large numbers of snails. By inspecting such traps regularly, it is possible to destroy a significant part of a snail population. This method is sufficiently satisfactory so that some private planters have in use over a thousand such traps on their leased beds. Their difficulty lies in the amount of labor required to handle and inspect them at regular intervals. Little else has been done towards controlling the snail other than the hand-culling which is practiced when tonging or dredging oysters. The use of the suction dredge and screening of the material as done in New England is not possible in the south because of the generally soft nature of the reef bottoms. Other factors which should be considered in planning possible control methods include the not very promising possibility of discovering some chemical cheap and selective enough to be dumped in the water to kill just the snails. A somewhat more hopeful idea is that of developing a biological control, such as the trematode parasite which invades the snail gonad and destroys its ability to reproduce. I offer two suggestions which eventually may prove helpful to the industry. The first of these, so far as I know, is an untouched field, i.e., the use of electrical currents--either in creating barriers to snail migrations or as a lure attracting them to traps. The second suggestion is the invention of a baited trap similar to those now in use but with the important addition that this trap should permit entry but not exit of the snails.

Butler, Philip A. 1955. Hotel Oyster Under-the-Sea. In: The Review, Morgan City, LA. (ERL,GB 017).

Butler, Philip A. 1957. Production and Utilization of Seed Oysters in the Gulf Area. Proc. Natl. Shellfish. Assoc. 47:19-22. (ERL,GB 020).

The variety of environmental conditions along the extensive Gulf Coast imposes a great diversity of techniques in oyster culture, making it difficult for one person to have available current information on the entire industry. For this reason, I have called upon marine biologists in each of the states for assistance in assembling some of the data essential to our discussion. I should like to acknowledge their helpfulness and cooperation in providing information; the interpretation placed upon these data and any errors in statement are my own.

Butler, Philip A. and Alfred J. Wilson, Jr. 1957. Continuous Water Sampler for Estimation of Daily Changes in Plankton. Proc. Natl. Shellfish. Assoc. 47:109-113. (ERL,GB 021).

The water collecting device described here has special features which may be of value to other investigators. Its application is limited to fixed installations such as docks. Its chief advantage lies in its capacity to collect a relatively small aliquot from a large mass of water during a period of one or more days. Such samples have obvious value for estimating average concentrations of both particulate matter in the plankton and dissolved ions including nutrient salts and trace elements.

Butler, Philip A. 1958. Simple Marine Vivarium. In: U.S. Fish Wildl. Serv. Bur. Commer. Fish. Fish. Leafl. 473. 3 p. (ERL,GB 022).

A living exhibit of marine shore animals is an excellent way to stimulate student interest in the interactions of animal and plant communities and to demonstrate many fundamental concepts of biology. Once established, if a few basic requirements are carefully followed, you can maintain an interesting vivarium of marine plants and animals for many weeks without replenishing the original supplies.

Butler, Philip A., Alfred J. Wilson, Jr. and Alan J. Rick. 1960. Effect of Pesticides on Oysters. Proc. Natl. Shellfish. Assoc. 51:23-32. (ERL,GB 025).

The objective was to develop reliable methods for detecting harmful effects on oysters that might be caused by sub-lethal concentrations of chemical substances commonly used in pest control. Special equipment recorded simultaneously and continuously the shell movements of ten oysters exposed to low concentrations of test chemicals and ten control oysters. Percentage decrease in activity of test oysters was measured. Shell growth of one-year-old oysters was found to be a more useful index than shell movement. Thresholds for inhibition of shell growth were determined for 11 pesticides, of which all showed effect on growth after 24 hours' exposure to one part per million and three (chlordane, heptachlor and rotenone) were effective at concentrations as low as one part in 100 million.

Butler, Philip A. 1961. Effects of Pesticides on Commercial Fisheries. In: Proc. Gulf Caribb. Fish. Inst., 13th Annual Session, Nov., 1960. James B. Higman, Editor. University of Miami, Gulf and Caribbean Institute, Coral Gables, FL. Pp. 168-171. (ERL,GB 026).

Both the Milford and Gulf Breeze workers have noted that the first evidence of toxicity of pesticides to shellfish is a decrease in growth rates. It is reasonable to suggest that our ability to evaluate this item may eliminate much costly and time-consuming work in the future. We are interested not only in the pollution levels causing acute toxicity and death, but also those causing more subtle reactions which over a period of time may affect reproductive potential and longevity. Using the growth of small oysters as a criterion of pesticide toxicity, we find two points of particular interest. After the lowest concentration of a chemical that causes a decrease in growth has been determined, we find that exposure to a further ten-fold dilution produces no apparent ill effects, even over a period of several weeks. Secondly, when adversely affected oysters are returned to clean sea water, the normal growth rate is reinstated within a short period of time, usually a few days. We may hope that so far as oysters are concerned, and perhaps other estuarine forms, that not only are subacute toxicities transitory but that they may be avoided by relatively small increases in the dilution factor. It is possible that under natural conditions and barring accidents, average dilution factors are so great that these chemicals pose no real threat to estuarine and marine forms. These items are not suggested to lull us into any feeling of security with regard to chemical pollution but rather to point out how a coordinated and productive research program can provide the basis for better resource management. Agricultural chemicals are here to stay. With sufficient knowledge of their immediate and residual effects, it will be possible for us to utilize them to the fullest extent and with minimum damage to our valuable natural resources both on land and in the sea.

Butler, Philip A. 1965. Reaction of Some Estuarine Mollusks to Environmental Factors. In: Biological Problems in Water Pollution, Third Seminar, 1962. Clarence M. Tarzwell, Editor. U.S. Public Health Service, Cincinnati, OH. Pp. 93-104. (ERL,GB 029).

For nearly 25 years, this laboratory has been concerned with identifying the environmental factors that permit our commercial species of mollusks to flourish. Studies have been conducted of Santa Rosa Sound, Florida, and adjacent areas known to be suitable for oysters but which support a relatively small commercial harvest because of the high concentration of natural predators. Santa Rosa Sound is approximately 40 miles long and presents a typical estuarine habitat, although it has two openings into the Gulf of Mexico. Land drainage into the Sound is sufficient to cause marked seasonal and tidal fluctuations in salinity. In the past, too many biological studies on oysters have been in the nature of crash programs, limited in time and, more often than not, concerned with elucidating problems that had ceased to exist. The convenience of this location and the presence of a permanent staff made it possible to initiate a long-term program to observe the normal range of environmental factors in conjuction with the fluctuations in a natural population of oysters. The unique facility of estuarine animals to adjust physiologically to more or less drastic environmental changes does not imply that they are equally successful under all conditions, but only that sufficient numbers survive to perpetuate the species. This was well demonstrated about 15 years ago when the upper Chesapeake Bay experienced a protracted period of flooding that extended into the mid-summer months. The oysters become, quite literally, bags of water and contracted perhaps a third in body size. Still, a very few managed to elaborate gametes, there was a late summer spawning, and the brood survived. Our studies in Florida have undertaken the collection of 'routine' data to determine what are normal conditions, and to delineate if possible, changes in the oyster population associated with specific changes in the physical or chemical environment. This report is a brief summary of some of our observations in the past decade, what the environment has offered, and how the oyster and other estuarine animals have responded.

Butler, Philip A. 1962. Effects on Commercial Fisheries. In: Effects of Pesticides on Fish and Wildlife: A Review of Investigations During 1960; U.S. Fish Wildl. Serv. Bur. Sport Fish. Wildl. Circ., 143. U.S. Fish and Wildlife Service, Washington, DC. Pp. 20-24, 28, 42-44. (ERL,GB 031).

All of the pesticides tested so far have been found toxic to marine animals at levels far below recommended application rates. It should be recognized, however, that the experimental testing has been done under laboratory conditions. There are no data to demonstrate that pesticidal chemicals do collect in estuaries following their proper use, except in those relatively rare situations in which they are intentionally applied directly to brackish waters. Laboratory testing shows that toxicity levels may vary depending on the age and species of animal, the formulation of the product, and the test conditions. This indicates that similar variability is to be expected under field conditions, and that generalized regulations for pesticide use may be either dangerous or inapplicable. There is evidence that some pesticides may have useful applications in the management of commercial fisheries. The specificity of others indicates the possibility of developing chemicals that will affect only noxious pests. There is reason to believe that with sufficient research data available, the proper use of chemical controls will not be incompatible with the efficient management of our commercial marine resources.

Butler, Philip A. 1962. Progress in Pesticide Research. In: Minutes of the Atlantic States Mar. Fish. Comm. 21st Annual Meeting, Sept. 26-28, 1962, Atlanta, GA. Atlantic States Marine Fisheries Commission, Mount Vernon, NY. 4 p. (ERL,GB 032).

Most of us are aware of the accelerated publicity and general interest in pesticide-wildlife relationships that has taken place in the past few months. The curious thing about this is the attitude that this problem is something new or, at the least, one that has been largely ignored by people who should be concerned with it. As you know this is far from the case. Problems connected with the use of chemical control agents have been of vital and continuing concern to regulatory agencies, producing manufacturers, and various segments of the general public for a good many years. I should like to present here a general summary of the Bureau of Commercial Fisheries' concern in this matter and what some of the specific problems are that we are now working on.

Butler, Philip A. 1963. Commercial Fisheries Investigations. In: Pesticide-Wildlife Studies: A Review of Fish and Wildlife Service Investigations During 1961 and 1962; U.S. Fish Wildl. Serv. Circ., 167. U.S. Gov. Print. Off., Washington, DC. Pp. 11-25. (ERL,GB 036).

The investigations fall into three categories. Still the most urgent and requiring a majority of the effort is the determination of the acute toxic levels of the more imporant chemicals now in use or expected to go into production soon. The second type of investigation involves observations of possible toxicity due to chronic exposure to relatively low concentrations. This work involves few species and only the most common pesticides, since observation periods extend approximately 6 months. Emphasis is placed on possible ill effects during the early growth of the test animals. The third phase of the program involves the evaluation of important chemicals under field conditions. The objectives are to relate laboratory findings to field results under varying conditions of terrain and weather so that pesticides having minimal effects on commercial fisheries can be identified.

Butler, Philip A. and Paul F. Springer. 1963. Pesticides--A New Factor in Coastal Environments. In: Transactions of the 28th North American Wildlife and Natural Resources Conference, March 4-6, 1963, Detroit, MI. James B. Trefethen, Editor. Wildlife Management Institute, Washington, DC. Pp. 378-390. (ERL,GB 037).

Pesticides are used so widely now that they must be reckoned a significant factor in the environments of fish and wildlife. Increasing attention is being devoted to study of their effects on important coastal resources. Chemicals may be directly toxic or exert an indirect influence through reduction of food-chain organisms or modification of the habitat. Another mode of action is biological concentration in successive food-chain organisms. Information is summarized on the known effects of pesticides on coastal life from plankton to mammals. Toxicity varies greatly among different organisms and chemicals. Some marine forms appear to be unaffected by recommended or registered pesticidal applications while others are susceptible to poisoning at concentrations of a fraction of a part per billion. Use of less persistent chemicals that are more specific for individual pests and less toxic to non-target organisms offers promise for the future, particularly when integrated with physical and biological methods of control.

Butler, Philip A. 1963. Progress Report on Pesticide Research. In: Minutes of the Atlantic States Mar. Fish. Comm. 22nd Annual Meeting, Sept. 24-26, 1963, Boston, MA. Atlantic States Marine Fisheries Commission, Tallahassee, FL. Pp. 133-135. (ERL,GB 038).

During this past year, there has been increasing public recognition of the fact that the synthetic organic pesticides are biotacides, i.e., they kill many kinds of plants and animals, not just those that are pests from man's point of view. Production of these chemicals exceeded 700 million pounds in 1961, and it is known that the annual production is steadily increasing. We may expect this trend to continue, not necessarily in increasing amounts but certainly there will be new formulations, new uses and new areas of application. A pesticide is essentially a labor saving device and our economy demands that these be developed to the fullest extent consistent with health and the preservation of our natural resources. There has been a substanial increase in the funding of the pesticide research program and this has permitted corresponding increases both in staff and physical facilities. Most of this report will consist of kodachrome slides depicting our activities.

Butler, Philip A. 1963. Pesticides and Estuarine Resources. In: Florida Notebook. Pp. 28-29. (ERL,GB 038A).

During this past year, there has been increasing public recognition of the fact that the synthetic organic pesticides are biotacides, i.e., they kill many kinds of plants and animals, not just those that are pests from man's point of view. Production of these chemicals exceeded 700 million pounds in 1961, and it is known that the annual production is steadily increasing. We may expect this trend to continue, not necessarily in increasing amounts but certainly there will be new formulations, new uses and new areas of application. A pesticide is essentially a labor saving device and our economy demands that these be developed to the fullest extent consistent with health and the preservation of our natural resources.

Butler, Philip A., Jack I. Lowe and Alfred J. Wilson. 1963. Uptake and Retention of Pesticides by Shellfish. In: Pesticide-Wildlife Studies, 1963: A Review of Fish and Wildlife Service Investigations During the Calendar Year; U.S. Fish Wildl. Serv. Circ., 199. U.S. Fish and Wildlife Service, Washington, DC. Pp. 10-12. (ERL,GB 039).

Most pesticides and particularly the chlorinated hydrocarbons have a toxic effect on marine shellfish. Oysters exposed to minute concentrations of agricultural chemicals show abnormal pumping activity, decreased shell growth and, at summer water temperatures, significant mortalities. Animals that are affected but not killed, when returned to clean water, soon recover from all outward aspects of damage. Earlier experiments showed that oysters exposed to DDT at levels of 1 to 1,000 ppb (µg/liter) show a progressive decrease in shell deposition as compared with controls, from approximately 20 percent at 1 ppb to 100 percent at 1,000 ppb. When such oysters are returned to unpolluted water, growth rates return to normal within 4 weeks. The objectives in the present study were to determine the amounts of selected pesticides stored by shellfish, where they were stored, and how long they persisted.

Butler, Philip A. 1963. Biological Laboratory, Gulf Breeze, Florida. Am. Zool. 3(3):367-368. (ERL,GB 042).

The Laboratory consists of nine buildings with approximately 5,000 square feet of working space devoted to offices, dry laboratory rooms, and administration; 1,000 square feet of wet laboratory rooms; and 2,000 square feet for storage and shop facilities. A permanent staff of 15 (2 Ph.D.; 5 M.S.), including the Resident Director, is conducting a research program devoted primarily to estuarine ecology. Special emphasis is placed on studies of cyclic changes in animal populations, the biology of commercial shellfish, and the effects of pollution due to agricultural chemicals. The Laboratory is located on a 15-acre ballast rock island in the center of a complex of shallow communicating bays, a sound, and the Gulf of Mexico. Several small rivers entering the area have a 4,000 square mile drainage basin. Habitats vary from fresh-water rivers to the open Gulf with a salinity approximately 32 o/oo. Fresh and salt-water marshes are extensive and less than half of the shore line is developed. The bottoms are predominantly clean hard sand with mud only in the deeper channels. The fauna is extremely diverse, and relatively few species are found in abundance.

Butler, Philip A. 1964. Commercial Fishery Investigations. In: Pesticide-Wildlife Studies, 1963: A Review of Fish and Wildlife Service Investigations During the Calendar Year; U.S. Fish Wildl. Serv. Circ., 199. U.S. Fish and Wildlife Service, Washington, DC. Pp. 5-28. (ERL,GB 043).

The objective of the research is to help maintain at its optimum level the production of wholesome and economically useful marine plant and animal products. We need to learn how to protect and preserve the marine environment from the possibly adverse effects of agricultural chemicals. Equally important is the search for specific pesticides that may be useful in improving the quality and quantity of fish harvests. The need for this research does not imply that the widespread use of pesticide forumlations automatically constitutes a serious threat to marine life. Rather, it emphasizes the fact that we have too little knowledge of this environment to predict the effects of natural or man-made changes, or to write meaningful regulations to protect the marine habitat.

Butler, Philip A. 1964. Bureau of Commercial Fisheries Pesticide Research Program. Fishboat.(April):1-2. (ERL,GB 044).

The Bureau's program is presently funded at approximately 200 thousand dollars; twelve full-time biologists and as many more temporary employees are working on the several projects. It is proposed to expand gradually the present program and, in addition, finance a greatly increased effort using facilities now available at state and university marine laboratories. We plan to establish estuarine monitoring stations at strategic locations in coastal areas supporting important commercial fishery harvests. We must find out soon just how great the danger of this pesticide pollution is to our estuaries, and what needs to be done to safeguard and preserve them for the generations to come.

Butler, Philip A. 1965. Effects of Herbicides on Estuarine Fauna. In: Proc. 18th Annual Meet. South. Weed Conf., Jan. 19-21, 1965, Dallas, TX. Pp. 576-580. (ERL,GB 053).

It is the responsibility of the Bureau of Commercial Fisheries to learn how to preserve and improve the aquatic environment so that the maximum sustained yield of fishery products may be obtained for the benefit of man. The estuarine environment, a mixing zone between our fresh water drainage basins and the oceans, makes up the most important area for the production of marine crops. This zone can make maximum utilization of sunlight energy and nutrients derived from the land in providing animal food. As a result, the majority of our marine animals spend some or all of their life span in these so-called nursery areas. These include shrimp, for example, which make up our most valuable harvest and menhaden which produce the greatest poundage. It was apparent from the first usage of synthetic organic pesticide compounds that their chemical stability made it possible for them to be washed eventually into estuarine areas. Some of them are dissolved in drainage waters, some absorbed on silt particles and some may be incorporated in plant and animal tissues that find their way into the estuary. Although we were aware of this possibility from the first, and have been investigating it for more than seven years, we are still uncertain as to the ramifications of the problem and the full significance of the residues that have been found in the natural environment. For the past several years, our Biological Laboratory at Gulf Breeze has been evaluating the effects of widely used commercial pesticides to determine their relative toxicity to an array of marine animals.

Butler, Philip A. 1966. Problem of Pesticides in Estuaries. Am. Fish. Soc. Spec. Publ. 3:110-115. (ERL,GB 054).

Despite two decades of research, the extent and importance of pesticide pollution in estuaries are poorly understood. Laboratory studies of their acute and chronic toxicity indicate that pesticides may be the cause of ill-defined but significant mortality, loss of production, and, perhaps, changes in the direction of natural selection in estuarine fauna. Preliminary investigations show the need for a continuing surveillance program to identify the seasonal and geographical distribution of pesticide pollution in estuaries.

Butler, Philip A. 1965. Oysters of Locmariaquer, by Eleanor Clark, 1964 (Book Review).. Trans. Am. Fish. Soc. 94(3):283-284. (ERL,GB 059).

This slim volume is an extraordinary concoction and distillation of oyster biology, human frailty, and some of the historical background of the sturdy Breton peasant. With sympathetic insight, the author silhouettes the stark environment of the oyster farmer in Brittany, his hopes and fears, and his acceptance of the harsh facts of earning a meager but proud living. There is much evidence of the thorough researching into the scientific literature that made possible the telling of this story. There is understanding and appreciation of the struggle which, through the years, has brought oyster culture to its present state of refinement. Interspersed between the minutiae of oyster anatomy, organogenesis, and the cultural requirements of Ostrea edulis are anecdotes that acquaint the reader with the fact and fancy associated with oysters since the time of the Greeks.

Butler, Philip A. 1965. Commercial Fishery Investigations. In: Effects of Pesticides on Fish and Wildlife: 1964 Research Findings of the Fish and Wildlife Service; U.S. Fish Wildl. Serv. Circ., 226. U.S. Dept. of the Interior, Fish and Wildlife Service, Washington, DC. Pp. 65-77. (ERL,GB 060).

Substantial progress was made by the Bureau of Commercial Fisheries in 1964 in assessing the impact of synthetic organic pesticides on the marine environment. The broad objective of this program is to determine to what extent fishery products are being damaged by the production or use of synthetic organic pesticides. Approximately half of the research projects were in the continuing program of ascertaining what concentrations of these chemicals have toxic effects on representative marine animals. The increased staff and budget made possible a broader investigation that emphazied the monitoring of pesticide residues in the environment, in the biota, and in processed food products. A major portion of the investigations has been at the Biological Laboratory at Gulf Breeze, Florida. Projects concerned particularly with commercial fishery products were conducted at the Technological Laboratory in Pascaguola, Mississippi. One project, to determine the effects of programs for forest insect control on the salmon fishery, was conducted at the Biological Laboratory in Auke Bay, Alaska.

Butler, Philip A. 1966. Pesticides in the Marine Environment. J. Appl. Ecol. 3(SUPPL.):253-259. (ERL,GB 061).

The increased use of DDT in America after 1946 was identified with accidental mortalities of freshwater fish and wildlife, but it was not until 1958 that the Government appropriated funds to investigate the toxic effects of synthetic organic pesticides on marine biota and to discover the extent to which the agricultural use of pesticides could contaminate the estuarine environment. Laboratory tests have been devised for testing the toxicity of pesticides to marine phytoplankton, crustacea, molluscs and fish, and about 150 chemical compounds have been evaluated. Environmental pollution by DDT at levels as low as 0.001 ppm causes marked reduction in oyster growth. Molluscs and fish concentrate and store organochlorine pesticides at levels many thousand times greater than that present in their environment. Some pesticides cause damage at the lowest levels tested when the exposure is sufficiently long. Others have a critical threshold below which no damage to test animals can be detected. A nationwide surveillance system has been initiated to monitor permanent mollusc populations and determine the extent of pesticide pollution in North American estuaries. Samples will be analysed monthly for residues of twelve widely used persistent pesticides.

Butler, Philip A. 1965. Bureau of Commercial Fisheries Pesticide Monitoring Program. In: Minutes of the 24th Annual Meeting of the Atlantic States Marine Fisheries Commission and Gulf States Marine Fisheries Commission Joint Meeting, Miami, FL, Oct. 6-8, 1965. Atlantic States Marine Fisheries Commission, Tallahassee, FL. Pp. 182-186. (ERL,GB 064).

There is no evidence that residues exist in any of our commercial fisheries products at levels that would constitute a human health hazard. However, knowledge of the seasonal or continuous existence of low levels of pesticide residues will make it possible to pin-point sources of pollution and perhaps enable us to eliminate it before a catastrophe occurs. Such data will help identify areas where pesticides may already be an important factor contributing to low productivity or suspected declines in commercial fishery popluations. They will be of inestimable value in identifying new sources of pollution, and will put us in a much better position to protect our marine environment.

Butler, Philip A. 1965. Pesticides. In: Sixteenth Annual Report (1964-1965) of the Gulf States Marine Fisheries Commission to the Congress of the United States and to the Governors and Legislators of Alabama, Florida, Louisiana, Mississippi, Texas. Gulf States Marine Fisheries Commission, New Orleans, LA. Pp. 35-36. (ERL,GB 066).

Research projects are continuing to refine older techniques and develop new methods for evaluating the effects of synthetic organic pesticides on marine biota and detecting the presence of pesticide pollution in the environment. Substantial progress is being made in methods for detecting the organophosphate compounds which are both highly toxic and relatively transitory in the estuary. The screening program is being broadened to include more test on microscopic plants that serve as food for oyster larvae, as well as tests on the larvae themselves. Modernization of an existing structure has added 1600 feet of efficient laboratory facilities for this microbiological work. Additional fiberglass tanks have been installed outdoors to increase our holding facilities for the shrimp and fish used in bioassay work. During the year, laboratory staff members discussed pesticide problems and research progress at six meetings in the Gulf states. Twelve research reports were published or approved for publication.

Butler, Philip A. 1966. Fixation of DDT in Estuaries. In: Transactions of the Thirty-First North American Wildlife and Natural Resources Conference, March 14-16, 1966, Pittsburgh, PA. James B. Trefethen, Editor. Wildlife Management Institute, Washington, DC. Pp. 184-189. (ERL,GB 067).

Plankton plays an important role in the introduction of pesticide contamination into the estuarine food web. Filter-feeding animals further concentrate these residues and immobilize significant amounts of DDT in benthic deposits where it becomes available to detritus feeders. DDT residues may be fatal to predators at different trophic levels depending on the amount ingested at one time. It is probable that higher death rates and significant losses in productivity exist undetected in estuarine fauna contaminated with DDT.

Butler, Philip A. 1966. Scientific Fish Study Is Readable (Book Review). In: Pensacola News Journal, Sunday, June 12, 1966. Pp. 5D. (ERL,GB 069).

This book is third in a series on the life sciences by different authors; earlier volumes described insects and plants.

Butler, Philip A. 1967. Pesticides Research. In: Seventeenth Annual Report (1965-1966) of the Gulf States Marine Fisheries Commission to the Congress of the United States and to the Governors and Legislators of Alabama, Florida, Louisiana, Mississippi, Texas. Gulf States Marine Fisheries Commission, New Orleans, LA. Pp. 35-37. (ERL,GB 071).

The evaluation of new pesticides and new formulations of those already in use continues to be a fundamental laboratory project. Tests are conducted under controlled laboratory conditions and consequently, indicate the relative toxicity of one pesticide to another rather than the actual effect that would take place under field conditions. During the year, approximately 225 tests were conducted. These established acutely toxic levels that would cause damage in 24 to 96 hours. Several chronic toxicity tests are underway in which fish and crabs are exposed to sublethal concentrations for periods of six to nine months to determine what effect this chronic type of pollution might have on economically important species. Two major projects have been completed and the reports are being prepared for publication. In the first, an inventory of macroscopic animals and plants occurring in the Pensacola Estuary during a 2-year period was made. This establishes current population densities and seasonal variations that can be expected. In the second study, the population dynamics of two common species of fish in the estuary were evaluated over a 2-year period. In both cases, our objective was to document these aspects of the biota while Pensacola Bay is still relatively unpolluted. These data will serve as a foundation in later years for interpreting the importance of man-made changes in the estuarine environment.

Butler, Philip A. 1968. Pesticide Residues in Estuarine Mollusks. In: Proceedings of the National Symposium on Estuarine Pollution, Aug. 23-25, 1967, Stanford, CA. Stanford University, Stanford, CA. Pp. 107-121. (ERL,GB 079).

Populations of sessile mollusks have distinct advantages as monitors of organochloride pollution in estuaries. Not the least of these are: sensitivity, ability to concentrate and lose residues, fixed position, and ease in handling. The described monitor program has shown that a majority of the estuaries in the United States are contaminated with organochloride pesticides, but not yet to the extent that they endanger man's food supply. The data have been useful in pinpointing sources of pesticide pollution and indicate areas in which we may expect to associate this type of pollution with declines in our commercial fishery resources.

Butler, Philip A. 1969. Bureau of Commercial Fisheries Pesticide Monitoring Program. In: Proceedings: Gulf and South Atlantic States Shellfish Sanitation Research Conference, March 21-22, 1967, Dauphin Island, AL. Richard J. Hammerstrom and William F. Hill, Jr., Editors. U.S. Govt. Print. Off., Washington, DC. Pp. 81-84. (ERL,GB 080).

Preliminary studies on the acute and chronic effects of organochlorine pesticides on estuarine fauna showed that DDT at concentrations of 10.0 parts per billion and less in the environment reduced oyster growth rates and increased fish and crustacean mortality. Oysters and other shellfish retain pesticide residues in their tissues at levels far exceeding the concentration in ambient waters. Periodic monitoring of pesticide residue in a natural oyster population showed that DDT levels fluctuated annually and could be correlated with environmental pollution. Because of lack of knowledge of the geographical extent of estuarine pesticide pollution, a monitoring program was initiated in 1965 in which shellfish and fish are analyzed monthly for residues of 11 of the more common organochlorine pesticides. More than 150 estuarine stations have been established in different drainage basins on the Atlantic, Pacific, and Gulf Coasts. This report presents some of the data and their biological significance.

Butler, Philip A. 1967. Toxic Substances in the Marine Environment. In: Interim Report of the National Technical Advisory Committee on Water Quality Criteria to the Secretary of the Interior. U.S. Federal Water Pollution Control Administration, Washington, DC. Pp. 249-269. (ERL,GB 083).

Estuaries are recognized as being of critical importance in man's harvest of economically useful living marine resources. It is in these areas that the maximum conversion of solar energy into aquatic plant life takes place and they are justly identified as 'nurseries' since so many animals utilize them for feeding their early life stages. Some species, such as the oyster, spend their entire life span in the estuary, while the shrimp and menhaden reside there only as juveniles. The salmon and a few others use the estuary primarily as a pathway. In sum, however, more than half of the nearly five billion pounds of fishery products harvested by U.S. fishermen annually is derived from animals dependent for their existence on clean estuarine waters during some part or all of their life cycle.

Butler, Philip A. 1968. Pesticides in the Estuary. In: Proceedings of the Marsh and Estuary Management Symposium, Louisiana State University, Baton Rouge, LA, July 19-20, 1967. John D. Newsom, Editor. Thos. J. Moran's Sons, Inc., Baton Rouge, LA. Pp. 120-124. (ERL,GB 085).

Organochloride pesticides contaminate the major drainage basins in the United States. Examples are given of how and when this pollution occurs, its effect on estuarine fauna, and its eventual dispersal.

Butler, Philip A. 1969. Pesticides in the Sea. In: Encyclopedia of Marine Resources. Frank E. Firth, Editor. Van Nostrand Reinhold Company, New York, NY. Pp. 513-516. (ERL,GB 087).

Pesticide pollution of the land and aquatic environments is well documented, but, despite intensive research on this problem in the past two decades, it is still not clear whether these chemicals are causing irrevocable damage to the environment. Pesticides are designed to control unwanted plant and animal populations. Evidence is growing, however, that the continued use of the persistent pesticide chemicals is producing environmental changes or residues in the food web that may cause reproductive failure and lead to the extinction or genetic alteration of some species. These possibilities are of special concern in the marine environment since eventually most of man's waste products find their way to the sea.

Butler, Philip A. 1969. Monitoring Pesticide Pollution. BioScience. 19(10):889-891. (ERL,GB 101A).

The many possibilities for subtle harmful changes resulting from the accidental or intentional transport of pesticides into estuaries prompted the Bureau of Commercial Fisheries to initiate a program in 1958 to assess the extent of the problem. The program had two major objectives: to determine the acute and chronic toxicity of the commonly used pesticides to representative estuarine animals under controlled test conditions; and to monitor the seasonal levels of polychlorinated pesticide pollution in the nation's estuaries where production of living marine resources is commercially important. This report describes the development of the monitoring segment of the program and summarizes regional trends in pesticide pollution levels as revealed by 3 years of data collection.

Butler, P.A. 1969. Significance of DDT Residues in Estuarine Fauna. In: Chemical Fallout: Current Research on Persistent Pesticides. Morton W. Miller and George G. Berg, Editors. Charles C. Thomas, Springfield, IL. Pp. 205-220. (ERL,GB 101B).

A nationwide program was initiated in 1965 to monitor residues of ten synthetic, chlorinated hydrocarbon pesticides in estuarine populations of fish and shellfish. About 160 stations have been established where samples are collected at thirty-day intervals for analysis by gas chromatography with electron capture. The summarized data show that estuarine pollution levels reflect the intensity of agriculture in the associated river basin. Most of the positive analyses show residue levels in the range of 10 to 200 µg/kg of DDT, DDE, or DDD; dieldrin and endrin residues are typical of a few estuaries. Because of occasional residues in the range of 10 to 20 µg/g in fish and oysters, experiments were undertaken to determine effects of a DDT-contaminated diet on fish and crustaceans. Dietary levels of 2 to 5 µg/g of p,p'-DDT caused 35 to 100% mortality within two to ten weeks in laboratory populations of shrimp, crabs, and fish. Animals killed by the diet usually contained significantly lower body residues of DDT than randomly selected living animals on the same diet. There was, however, essentially no correlation between the amount of DDT residue and the size of the animal or the length of time it fed on the contaminated food. The experimental and monitoring data indicate that existing widespread pesticide pollution is causing significant decreases in productivity of estuarine populations of fish and shellfish. Resistant surviving animals are instrumental in concentrating and transmitting lethal amounts of pesticide residues in the food web.

Butler, Philip A. 1969. Sub-Lethal Effects of Pesticide Pollution. In: Biological Impact of Pesticides in the Environment: A Symposium Assessing the Significance of Pesticides in Relation to Ecological Problems and Health. James W. Gillett, Editor. Oregon State University Press, Corvallis, OR. Pp. 87-89. (ERL,GB 101C).

The Bureau of Commercial Fisheries is charged with the responsibility for determining those factors in the aquatic environment that will enable man to harvest the maximum amount of useful fishery products on a sustained yield basis. Some of the areas of investigation include, for example, exploratory fishing and gear research, population dynamics, taxonomy, and management. In recent decades, pollution resulting from man's activities has become a major problem in many areas. A corresponding increase in research effort has been required to identify kinds and sources of pollution and its effects on aquatic resources.

Butler, Philip A., Ray Childress and Alfred J. Wilson. 1972. Association of DDT Residues with Losses in Marine Productivity. In: Marine Pollution and Sea Life. Ruivo Mario, Editor. Fishing News Books, Ltd., London. Pp. 262-266. (ERL,GB 101D).

Conclusions: (1) Agricultural use of DDT is the chief source of DDT contamination of the estuarine environment in Texas. (2) Trophic magnification of DDT residues in the estuarine food web resulted in the reproductive failure of seatrout populations in the lower Laguna Madre, Texas in 1969. (3) Seatrout populations in other Texas estuaries were not harmed because of different food chain interactions. (4) Data suggest that estuarine sediments build up to a plateau of DDT residues over a period of years and these residues do not reflect the seasonal levels of waterborne pesticide pollution in the environment. (5) Sedimentary residues of persistent DDT may be resuspended physically by storms and recycled in the biota. (6) Restrictions on the agricultural use of DDT were reflected by decreased residues in estuarine biota in adjacent estuarine areas within three years. (7) The reproductive capacity of long-lived fish populations damaged by DDT residues may be restored by prohibiting the use of DDT in adjacent drainage basins.

Butler, P.A. 1971. Influence of Pesticides on Marine Ecosystems. Proc. R. Soc. Lond. B Biol. Sci. 177:321-329. (ERL,GB 129).

A bioassay programme undertaken in 1958 has evaluated the toxicity of about 240 pesticides to estuarine fauna. Studies indicate that chronic levels of sublethal amounts of pesticides may have more damaging effects than transitory changes due to acutely toxic levels of pollution. The first five years of a programme monitoring the incidence of synthetic pesticide residues in populations of North American shellfish has been completed. The results demonstrate the ubiquity of DDT and its metabolites. Levels of contamination, however, are not high enough to indicate a human health problem. The run-off of surface waters from agricultural districts is indicated as the chief source of this type of pollution; municipal and industrial wastes, and the control of noxious insects are regionally important sources. Observations of laboratory populations experimentally contaminated with DDT indicate, by extrapolation, that pesticide pollution is causing significant changes in mortality, growth rates, or resistance to disease in some marine populations.

Butler, P.A., L.E. Andren, G.J. Bonde, A.B. Jernelov and D.J. Reish. 1972. Test, Monitoring and Indicator Organisms. In: Guide to Marine Pollution. Edward D. Goldberg, Editor. Gordon and Breach, London. Pp. 146-159. (ERL,GB 148).

This material has been prepared to enable the investigator to select bioassay organisms which will be most useful for the detection and evaluation of pollution. Ideally, the selected species or community of different species would reflect not only the presence or absence of specific pollutants but also relative pollution levels and their periodic fluctuations, and perhaps identify factors other than chemical that contribute to environmental degradation. The species selected should be of value in circumscribed geographic locations as well as in larger water areas. Such an ideal type does not exist, of course, and bioassay organisms may be grouped functionally into two general categories as either monitoring or indicator types. The demarcation between these two is not always sharp and there are numerous exceptions to the following generalized definitions.

Butler, Philip A. 1973. Organochlorine Residues in Estuarine Mollusks, 1965-72--National Pesticide Monitoring Program. Pestic. Monit. J. 6(4):238-362. (ERL,GB 155).

This paper describes the development of the national program for monitoring estuarine mollusks in 15 coastal States and reports the findings for the period 1965-72. The report is presented in two parts: Part I. General Summary and Conclusions, and Part II. Residue Data--Individual States. Analyses of the 8,095 samples for 15 persistent organochlorine compounds showed that DDT residues were ubiquitous; the maximum DDT residue detected was 5.39 ppm. Dieldrin was the second most commonly detected compound with a maximum residue of 0.23 ppm. Endrin, mirex, toxaphene, and polychlorinated biphenyls were found only occasionally. Results indicate a clearly defined trend towards decreased levels of DDT residues, beginning in 1969-70. At no time were residues observed of such a magnitude as to imply damage to mollusks; however, residues were large enough to pose a threat to other elements of the biota through the processes of recycling and magnification.

Butler, Philip A. 1972. DDT in Estuarine Molluscs. BioScience. 22(12):690-691. (ERL,GB 155A).

One segment of the National Monitoring Program has been concerned with organochlorine pollution in estuaries. A summary of the data collected in 1965-68 was published in 1969 (BioScience, 19:389). That report discussed the usefulness of pelecypod molluscs (oysters, clams, mussels) as bioassay tools because of their sensitivity to these pollutants at parts-per-trillion levels and because tissue residues were quickly flushed away when the pollution was interrupted for periods as short as 2 weeks. This monitoring program was terminated in June 1972. A manascript discussing the results and including the analytical data of the 8095 samples has been submitted for publication to the Pesticides Monitoring Journal. The overall conclusions of this program are of sufficient general interest to warrant this brief comment.

Butler, Philip A. 1974. Trends in Pesticide Residues in Shellfish. Proc. Natl. Shellfish. Assoc. 64(JUNE):77-80. (ERL,GB 176).

The National Estuarine Monitoring Program, a cooperative effort between the State and Federal Governments, collected and analyzed shellfish samples for persistent synthetic pesticides at monthly intervals during the years 1965-1972 in 15 coastal states. The recently completed study of the 8000-plus analyses demonstrates that: (1) the residues found, primarily DDT and its metabolites, were universally too low to have human health significance, (2) areas of both high and low residues were clearly defined geographically, (3) in some areas there has been a trend towards a wider distribution of smaller residues, and (4) there has been a marked decline generally in DDT residues since 1968 when peak levels in molluscs were detected.

Butler, P.A. 1974. Biological Problems in Estuarine Monitoring. In: Proceedings of Seminar on Methodology for Monitoring the Marine Environment, Seattle, WA, Oct. 1973. EPA-600/4-74-004. U.S. Environmental Protection Agency, Washington, DC. Pp. 126-138. (ERL,GB 191). (Avail. from NTIS, Springfield, VA: PB-239 052)

Monitoring programs have several basic functions and requirements. First, they should record existing residues of persistent pollutants that occur at significant trophic levels in aquatic ecosystems. Sample collection protocols, as well as analytical procedures, must be sufficiently standardized to ensure the comparability of data, not only from one area to another but also from year to year. It is essential that monitoring programs collect comparable data for sufficiently long periods of time so that pollution trends can be identified. Finally, it should be stressed that monitoring data must be transmitted on a timely basis to action agencies. Agencies mandated to identify and regulate pollution sources, agencies with resource protection responsibilities, and agencies concerned with human welfare must have clearly established communication channels with environmental monitoring programs.

Butler, Philip A. 1974. Estuaries. In: Guidelines on Sampling and Statistical Methodologies for Ambient Pesticide Monitoring. Federal Working Group on Pest Management, Washington, DC. Pp. v-1-v-5. (ERL,GB 245).

The decision to monitor an estuary for pesticides may derive from any one or several specific needs. These needs or objectives will largely determine the character and modus operandi of the program. Obviously, two pesticide monitoring programs in the same estuary might be entirely different because of the kinds of information sought. Estuarine monitoring objectives may be for the purpose of determining: 1. Background levels of an array of persistent waterborne pesticides by randomized sampling of estuaries in a particular geographical area. 2. The escapement of pesticides in surface run-off from specific use areas in the drainage basin by sampling deltaic sediments. 3. The cause of increased faunal mortalities or lack of species diversity in an otherwise normal appearing estuary. 4. Tissue residue levels of persistent pesticides to ensure that they are within legal tolerance levels for edible fish and shell fish or their products. 5. Pesticide residues in food chain organisms to alert resource management agencies of possible mortalities resulting from trophic magnification. 6. Pesticide residues in pre-spawning gonads of commercially valuable species to identify causes of change in productivity. The choice of which physical or biological elements are to be monitored in an estuary will be determined by specific program objectives.

Butler, Philip A. 1977. National Estuarine Monitoring Program. In: Estuarine Pollution Control and Assessment: Proceedings of a Conference, Vol. II. EPA-440/1-77-007. U.S. Environmental Protection Agency, Office of Water Planning and Standards, Washington, DC. Pp. 519-521. (ERL,GB 263).

About 8,000 samples of estuarine molluscs were monitored for pesticide residues in the period 1965-1972. Residue trends and typical pollution situations are briefly described. Beginning in 1972, fish were substituted for molluscs. The basic needs for a continuing monitoring program are described.

Butler, Philip A. and Roy L. Schutzmann. 1978. Residues of Pesticides and PCBs in Estuarine Fish, 1972-76--National Pesticide Monitoring Program. Pestic. Monit. J. 12(2):51-59. (ERL,GB 334).

This report summarizes 1524 analyses of juvenile fish collected semiannually in 144 estuaries nationwide from July 1972 through June 1976. Pooled samples of 25 whole fish were screened for 20 common pesticides and polychlorinated biphenyls (PCBs). The three most common residues, DDT, PCBs, and dieldrin, were found in 39, 22, and 5 percent of the samples, respectively. Data indicate that estuarine pollution levels continue to decline.

Butler, P.A. and R.L. Schutzmann. 1979. Bioaccumulation of DDT and PCB in Tissues of Marine Fishes. In: Aquatic Toxicology, ASTM STP 667. EPA-600/J-79-081. L.L. Marking and R.A. Kimerle, Editors. American Society for Testing and Materials, Philadelphia, PA. Pp. 212-220. (ERL,GB 337). (Avail. from NTIS, Springfield, VA: PB80-185234)

Fishes of commercial importance were monitored in New England coastal waters in 1974 to determine whether synthetic residues in the fish were large enough to affect the utilization of such fish as food by man or to interfere with their ability to reproduce. About 700 fish of 20 species were pooled in samples of five to ten, and the livers were analyzed. Several species, including the spiny dogfish, contained residues of dichlorodiphenyltrichloroethane (DDT) and its metabolites and of polychlorinated biphenyl (PCB) compounds in the 1 to 10 µg/g (ppm) range. More detailed studies of the dogfish in 1975 demonstrated the transfer of these compounds from the parent fish to the ovarian egg and the mature fetus. The proportions of the DDT metabolites found suggest that this pesticide had been accumulating in the 18 to 20-year period of maturation of the female and was passed on to the first brood of young. In contrast to the findings of other investigations, there was no fixed relationship in the relative magnitude of DDT and PCB residues when both compounds were present in a sample.

Butler, Philip A. 1982. Monitoring Agricultural Chemicals in Estuaries. In: Proceedings of the Workshop on Agrichemicals and Estuarine Productivity, Duke University Marine Laboratory, Beaufort, North Carolina, 18-19 September, 1980. U.S. National Oceanic and Atmospheric Administration, Boulder, CO. Pp. 213-220. (ERL,GB 418).

This discussion defines monitoring as the identification of change. Principal monitoring strategies are defined as historic, mandatory, and fortuitous. Case histories of representative programs differentiating these categories are presented with discussions of their limitations and potential for constructive achievements. Some of the difficulties encountered in the interpretation of data generated by programs monitoring agricultural chemicals are depicted. There is an assessment of future needs in the field of estuarine monitoring and a discussion of some of the factors that are leading to a predictable decline in the importance of field monitoring studies.

Butler, Philip A. 1985. Synoptic Review of the Literature on the Southern Oyster Drill Thais haemastoma floridana. NOAA Tech. Rep. NMFS; 35. 9 p. (ERL,GB 500). (3-15-85)

This literature search identifies a majority of the publications in the period 1880-1980 concerned with the marine gastropod. Thais haemastoma floridana (Conrad). The southern oyster drill is an economically important oyster predator in the western Atlantic and Gulf of Mexico littoral. Major contributions of each paper to our knowledge of the drill's biology are briefly categorized. Hitherto unpublished research by the author on the snail's biology is documented.

Butler, Philip A., Charles D. Kennedy and Roy L. Schutzmann. 1978. Pesticide Residues in Estuarine Mollusks, 1977 Versus 1972--National Pesticide Monitoring Program. EPA-600/J-78-168. Pestic. Monit. J. 12(3):99-101. (ERL,GB X018). (Avail. from NTIS, Springfield, VA: PB-183 395)

Bivalve mollusks were monitored for residues of 20 organochlorine and organophosphate pesticides and polychlorinated biphenyls in spring 1977 in 87 of the 181 estuaries routinely monitored on a monthly basis during 1965-72. DDT, the only pesticide detected in 1977, occurred at low levels in one estuary each on the Atlantic and Pacific coasts.

Butler, P.A. and J.I. Lowe. 1978. Flowing Sea Water Toxicity Test Using Oysters (Crassostrea virginica). In: Bioassay Procedures for the Ocean Disposal Permit Program. EPA-600/9-78-010. U.S. Environmental Protection Agency, Environmental Research Laboratory, Gulf Breeze, FL. Pp. 25-27. (ERL,GB X019).

The following test procedure is included as a 'special bioassay' for evaluating short-term effects of specific wastes on marine mollusks. It is recommended only for use with the commercial eastern oyster, Crassostrea virginica, and requires flowing unfiltered, natural sea water. This test should be used only with materials which can be dissolved in water or other solvents. The test has proven valuable at ERL, Gulf Breeze, where is has been used for several years to evaluate the effect of insecticides, herbicides, and other toxic organics on oysters.

Butler, P.A. and J.I. Lowe. 1976. Flowing Sea Water Toxicity Test Using Oysters (Crassostrea virginica). In: Bioassay Procedures for the Ocean Disposal Permit Program. EPA-600/9-76-010. U.S. Environmental Protection Agency, Environmental Research Laboratory, Gulf Breeze, FL. Pp. 81-83. (ERL,GB X020).

The following test procedure is included as a 'special bioassay' for use in evaluating short-term effects of specific wastes on marine molluscs. It is recommended only for use with the commercial eastern oyster, Crassostrea virginica, and requires flowing unfiltered, natural sea water. This test should be used only with materials which can be dissolved in water or other solvents and then metered into test aquaria. The test has proved to be a valuable bioassay procedure at the Gulf Breeze Environmental Research Laboratory (EPA) where it has been used for several years to evaluate the effects of insecticides, herbicides, and other toxic organics on oysters.

Butler, Philip A., Robert Huggett, Kenneth Macek, Robert Reinert and Robert Risebrough. 1979. Synthetic Organics. In: Proceedings of a Workshop on Scientific Problems Relating to Ocean Pollution, Estes Park, CO., July 10-14, 1978. U.S. National Oceanic and Atmospheric Administration, Environmental Research Laboratories, Boulder, CO. Pp. 13-22. (ERL,GB X022).

Past experiences with synthetic organics in aquatic systems should be used as guidelines for studies involving these materials. In the future we cannot allow, as we have in the past, synthetic organic compounds to accumulate in the aquatic environment to the point that they have detrimental effects. Our past experience suggests we must develop methods to inventory the increasing numbers of synthetic organics that are being detected in the aquatic environment, and we must develop a priority system for determining the order in which these materials are to be tested for their effects on aquatic organisms. At present, the state-of-the-art in pollution work involving the detection of synthetic organics is much more advanced than our capabilities for determining the effects of these materials on the environment.

Butler, Philip A. 1979. Use of Oysters and Related Molluscs as Biological Monitors of Synthetic Organic Pollutants. In: Monitoring Environmental Materials and Specimen Banking. N.P. Luepke, Editor. Martinus Nijhoff Publishing, The Hague. Pp. 156-164. (ERL,GB X023). (West)

This report discusses the National Pesticide Monitoring Program in estuaries of the United States. Molluscan samples were collected monthly at about 180 stations during the period 1965-72. Half of these stations were monitored again in 1977. The significant findings of the programs are presented and illustrated. The coordination of the program is described, as well as the collection and processing of samples, data, handling, and program costs. The biology of molluscs is described as it relates to their suitability as biomonitors. Some of the details of the laboratory experiments are given to characterize the reaction of molluscs to pesticides under controlled conditions. Despite the necessity for short-term sampling, or because of it, bivalve molluscs appear to be the most useful biomonitor for indicating the fluctuating levels of pollution by synthetic organics in the aquatic environment. Their usefulness is a result of the combination of their ubiquity, ease in handling, sensitive physiology, position in the food web, and the large store of data describing their responses to pollution under controlled conditions in the laboratory.

Butler, Philip A. 1970. Biological Aspects of Water Pollution (Book Review). Q. Rev. Biol. 45(1):30s. (ERL,GB X342).

C.G. Wilber describes in 16 chapters the more significant aspects of man-made pollution in the freshwater and marine environments. The text has been organized to reflect the urgency of the pollution situation by describing selected problems rather than to provide a comprehensive review of the subject and associated literature.

Butler, Philip A. 1965. Use of Pesticides to Control Predator Populations. In: U.S. Fish Wildl. Serv. Circ. 247. U.S. Dept. of the Interior, Washington, DC.. Pp. 13. (ERL,GB X454).

Research at the Bureau of Commercial Fisheries Biological Laboratory, Milford, Conn., demonstrated the usefulness of Polystream, a mixture of chlorinated benzenes, in the control of snail predators on New England oyster beds. Since similar snails cause serious damage to Gulf oysters, we undertook studies to evaluate the usefulness of this chemical here. With the cooperation of the University of Alabama and the Alabama Department of Conservation, plantings of reef oysters and bareshell cultch were made on 10 quarter-acre plots in Mobile and Pensacola Bays. The two areas selected were suitable for oysters but had none because of the snails present. The Pensacola area has a sand bottom, and the Mobile Bay area had a mud bottom. Preliminary tests in the laboratory showed that other marine animals were unaffected by application of the pesticide at the recommended rate. The plots of oysters and shells received a single treatment in July; suitable plots were left untreated as controls. During the remainder of the summer and in the following spring, biological samples were removed from the plots at regular intervals. The results in both areas were similar and essentially negative. The treatment had no effect in controlling drills or causing any other observable effect on the population dynamics of any of the bottom fauna. We believe that there was sufficient siltation in both areas to cover the deposit of the granular pesticide and render it ineffective. The project was terminated, and a final report is being prepared.

Butler, Philip A. 1965. Population Dynamics of Sedentary Fauna. In: U.S. Fish Wildl. Serv. Circ. 247. U.S. Dept. of the Interior, Washington, DC.. Pp. 13. (ERL,GB X455).

Major fluctations in the population density of estuarine forms are frequently noted, but the minor changes occurring seasonally and perhaps in longer cycles are difficult to identify. We have found that the setting index of some sedentary animals, including protozoa, polychaete worms, hydroids, bryozoa, mussels, oysters, and barnacles provides an objective criterion of population fluctuations. Consequently, as a continuing project, and for the past 15 yrs., such data have been recorded at 7-day intervals at the Laboratory island in conjunction with continuous records of changes in salinity, air and water temperature, tides, and precipitation. We anticipate that with these records as a foundation, we will be able to document population changes and explain their causes as being due to 'normal' cycles or as resulting from physical changes in the environment or chemical changes caused by domestic, industrial, or pesticidal pollution.

Butler, Philip A. 1965. Pesticide Pollution in Estuaries. In: U.S. Fish Wildl. Serv. Circ. 247. U.S. Dept. of the Interior, Washington, DC.. Pp. 14. (ERL,GB X457).

It was apparent from laboratory experiments that to detect the low levels of pesticide pollution capable of causing harm in the environment, biological monitors could be more instructive than chemical tests. Various species of the native fauna were periodically examined for pesticide residues. We found in the course of repeated monthly examinations in a relatively unpolluted estuary such as Pensacola Bay, that plankton, mollusks, and fish more often than not had chlorinated hydrocarbon pesticide residues, and that these residues fluctuated, apparently erratically. In the laboratory under controlled conditions, oysters and mussels were found to be much more efficient in storing residues than clams, gastropods, crabs, shrimp, and fish. Oysters stored pesticides at levels proportionate to the amount present in the environment, and these residues were flushed out when the environment was 'clean.' Casual samples of fish and oysters from other coastal areas indicated that residues of the chlorinated hydrocarbon pesticides might be widely but unpredictably distributed.

This study indicates that organophosphorus pesticide pollution in estuaries along the Atlantic and Gulf coasts is not yet widespread, but should be followed, preferably by a technique that is dependable and not too costly. The techniques used by us are relatively straightforward and could readily be employed by other laboratories at moderate expense. The chief difficulty lies in the mechanics of handling and shipping the frozen samples. We suggest several modifications of our procedures which would decrease the time required for AChE determinations without detracting from the value of the data. The 4-hour incubation period following homogenization of the brain tissue can be eliminated; a trained operator could then complete approximately 25 samples per day. Instead of analyzing individual fish, brains of 5 to 10 fish of uniform size from a station can be analyzed as a composite sample and yield a statistically valid datum. Additional fish species are presumably suitable for use as monitors; we are currently evaluating several species of the genus Fundulus for this purpose. Use of these techniques for the periodic surveillance of estuarine fish populations will enable the biologist to recognize incipient and chronic low levels of organophosphorus pollution in estuaries. Armed with such data, we can initiate remedial action before an environment is permanently destroyed.

Holland, H.T., David L. Coppage and Philip A. Butler. 1966. Increased Sensitivity to Pesticides in Sheepshead Minnows. Trans. Am. Fish. Soc. 95(1):110-112. (ERL,GB 075).

Reports of resistance in fishes to various pesticides are based on relative toxicity data for fish collected from areas of heavy pesticide usage and fish from areas known to be free of contamination. This apparent resistance was shown to persist through several generations, but the selective agent and number of generations required to produce a resistant population are unknown. The purpose of this study was to determine whether genetic resistance to pesticides in sheepshead minnows (Cyprinodon variegatus) could be demonstrated by testing the F1 generation of fish surviving DDT concentrations exceeding the median tolerance limit (TLm).

West, Walter L. and Philip A. Butler. 1968. Mechanical Testing and Bioassay of Adhesive/Sealants for Use in an Aquatic Environment. Drum and Croaker (Wash.). 68(1):9-10. (ERL,GB 089).

In 1965, specific tests were begun to determine the material best suited and commercially available as an adhesive/sealant for large and small scale aquarium use. In most cases, the materials were not initially intended for aquarium or underwater uses. The testings were designed for two purposes: 1. Determine the toxicity of the materials to aquatic organisms. 2. Determine the suitability of the materials to seal hair-like cracks on the water side of concrete tanks, ease the removal of algae, and determine if these materials could be used to seal the periphery of viewing glass. The testing under (1) above was done under contract at the Steinhart Aquarium, San Francisco and at the Gulf Breeze, Florida, laboratory of the U.S. Bureau of Commercial Fisheries. The testing under (2) above was by the NFCA staff and the National Fish Hatchery, Pisgah Forest, North Carolina.

Holden, Alan V., Marguerita Barros, Philip A. Butler, Egbert G. Duursma, George Harvey, Michel Marchand-Stavre, G.B. Marcos and I. Salihoglu. 1980. Halogenated Hydrocarbons. In: International Mussel Watch: Report of a Workshop Sponsored by the Environmental Studies Board Commission on Natural Resources National Research Council. National Academy of Sciences, Washington, DC. Pp. 133-142. (ERL,GB X143).

Halogenated hydrocarbons, and particularly DDT, DDE and PCBs, are transported to a significant extent through the atmosphere and have been detected in all regions of the world. The substances, which have been produced only by man, are now as widely distributed as natural substances, although, in the case particularly of the PCBs, their use is confined to limited areas of the world. Natural processes of atmospheric transport lead inevitably to the redistribution of halogenated hydrocarbons to areas where no use exists or can be anticipated, and it is to be expected that in these areas the background level will increase slowly, although not necessarily to concentrations at which biological effects could occur. Nevertheless, it may be considered prudent to monitor concentrations in such areas to assess the extent of contamination and to measure the trend in concentrations of substances such as PCBs, DDT, and DDE over a long period. The panel discussed both the question of alternatives to bivalves as material for assessing pollution in coastal waters and strategies required for determination of any organohalogen contamination in the samples selected. As the organohalogen group includes several hundred compounds of various types and uses, and of widely differing chemical properties, the panel decided that only a limited number of more persistent compounds with widespread occurrence should be measured in any monitoring program. The specific compounds will be determined by use patterns in the respective areas, although in all cases PCBs should be analyzed.