Tidal amplitude and fish abundance in the mouth region of a small estuary.
Using an acoustic underwater camera (Dual Frequency IDentification SONar, DIDSON), the abundance and direction of movement of fishes > 80 mm total length (LT ) in the mouth of a small South African estuary during spring and neap tidal cycles were observed. While the sizes of fishes recorded were consistent across both tide cycles, the number of fishes passing the camera was significantly greater during the smaller neap tides. Schooling behaviour was more pronounced for fishes that were travelling into the estuary compared to fishes swimming towards the ocean.
South African Institute for Aquatic Biodiversity, Private Bag 1015, Grahamstown, 6140, South Africa.|Port Stephens Fisheries Institute, NSW Department of Primary Industries, Nelson Bay, NSW, 2316, Australia.
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A
Becker
South African Institute for Aquatic Biodiversity, Private Bag 1015, Grahamstown, 6140, South Africa.
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Whitfield
South African Institute for Aquatic Biodiversity, Private Bag 1015, Grahamstown, 6140, South Africa.
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PD
Cowley
South African Institute for Aquatic Biodiversity, Private Bag 1015, Grahamstown, 6140, South Africa.|School of Life and Environmental Sciences, The University of Sydney, NSW, 2006, Australia.
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VJ
Cole
Port Stephens Fisheries Institute, NSW Department of Primary Industries, Nelson Bay, NSW, 2316, Australia.
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MD
Taylor
D000818:Animals; D063366:Estuaries; D005399:Fishes; D011157:Population Dynamics; D012621:Seasons; D013019:South Africa; D013550:Swimming; D055871:Tidal Waves
South Africa; acoustic camera; connectivity; schooling