Flume weir for quantitative collection of nekton from vegetated intertidal habitats

Abstract

The flume weir samples a relatively large and precisely defined area (100 m2) without affecting the normal movement patterns of nekton into or out of the sampling area until the moment a sample is required. The mean efficiency with which fish and crustaceans ≥30 mm in length were recovered from flume weirs was in the range 86 to 99%. Twenty species of fish and four species of crustaceans were collected in flume weir samples taken from intertidal marsh sites adjacent to Sapelo Island, Georgia. Adults and juveniles of small resident marsh species composed 82.3% of the total individuals collected. Juveniles of seasonal migrant species, which use marshes as nurseries were also common. The most abundant of these was white shrimp Penaeus setiferus, which was present only from June-November, but composed 12.9% of the total nekton collected. Other common seasonal species were mullet Mugil spp. and spot Leiostomus xanthurus, which represented 1.7 and 1.6% of the total catch, respectively. -from Author