Research Product

This paper describes the design and application of a remotely deployed enclosure trap used to quantitatively sample nekton associated with shallow estuarine habitats. A seine with added weight and flotation is deployed from the stern of a small, non-motorized skiff and is used in conjunction with a specially designed cod end holding box. The design of this gear permits rapid entrapment of nektonic organisms while generating minimal disturbance that may ward off target species. This capability is useful in habitats where use of a trawl is not particularly feasible because risk of snags or where rapid escaping species are not efficiently captured with a standard haul seine. This gear has value as a quantitative tool for comparative sampling of different habitat types. With minor modifications, the design could be readily adapted for use in other structured intertidal habitats such as marshes and submerged aquatic vegetation beds. The utility of the enclosure net and cod end design is demonstrated for capturing nekton on and around oyster reefs and intertidal sand flats. We used mark-recapture techniques to estimate the recovery efficiency of nekton in this enclosure trap and make comparisons with more conventional haul seine techniques. Overall nekton recovery efficiency of the enclosure trap gear was high, averaging 74.8% ± 1.7% (mean ± I SE), and was significantly higher than that of a standard haul seine (57.8 % ± 2.8%). There were no significant differences in recapture rates between the two habitat types tested. The rapid and quiet deployment of this gear combined with our tests of recovery efficiency using mummichog Fundulus heteroclitus and spot Leiostomus xanthurus suggest that this remotely-deployed enclosure seine and removable cod end is a reliable and effective sampling tool for nekton in intertidal habitats.