Nekton use of different habitat types in seagrass beds of Lower Laguna Madre, Texas

Date

2003 Jan

Authors

Sheridan P
Minello TJ

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Abstract

We compared densities of fishes and decapods among three types of undisturbed seagrass beds (Halodide wrightii, Syringodium filiforme, and Thalassia testudinum) and three dredged material areas (old deposits revegetated by mixed seagrasses, and new experimental deposits planted with Halodule wrightii or left to revegetate naturally). Planted beds failed, and both types of experimental deposits remained nonvegetated sandy mud throughout the study. We collected nekton with a 1-m(2) enclosure sampler in spring and fall of both 1996 and 1997, simultaneously collecting data on seagrass, sediment, and water column characteristics. Densities of total fishes, total decapods, and most numerical dominants were usually significantly higher in seagrass beds compared with nonvegetated bottom, as were fish and decapod biomasses. Among seagrass beds, nekton densities were often significantly higher in revegetated dredged material and Thalassia testudinum, particularly in spring. Regression models indicated that densities of most dominant species were related primarily to seagrass characteristics and less to sediment or water column parameters. Nekton densities in Lower Laguna Madre seagrass beds were typically lower than those found elsewhere in the Gulf of Mexico, but the large acreage of seagrasses in this estuary probably supports the high fisheries productivity found along the south Texas coast

Description

37-61

Keywords

HALODULE-WRIGHTII ASCHERS, PRAWNS PENAEUS-ESCULENTUS, SITU LIGHT REDUCTION, COVERED MUD BANKS, FISH ASSEMBLAGES, FLORIDA BAY, THALASSIA-TESTUDINUM, AUSTRALIAN ESTUARY, SEASONAL GROWTH, GALVESTON BAY

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