Estuarine Fish Responses to Strobe Light, Bubble Curtains and Strobe Light/Bubble-Curtain Combinations as Inf luenced by Water Flow Rate and Flash Frequencies

Sager, D.R., Hocutt, C.H. and Stauffer, J.R., Jr., 1987. Estuarine fish responses to strobe light, bubble curtains and strobe light/bubble-curtain combinations as influenced by water flow rate and flash frequencies. Fish. Res., 5: 383-399. This study examined the possible use of strobe lights and strobe light/bubble-curtaincombinations as behavioral guidance systems for estuarine fish. White perch (Morone americana), spot (Leiostomus xanthurus) and Atlantic menhaden (Brevoortia tyrannus) were tested in a behavior experimental tank for avoidance to strobe lights, bubble curtains and strobe light/bubblecurtain combinations at different water flow rates, strobe flash frequencies and light acclimations. Percentage avoidance of strobe light ranged from 8 to 36% for white perch, from 8 to 100% for spot and from 8 to 68% for menhaden, depending on the conditions tested. Z'-' analyses indicated significant ( P < 0.05) avoidance by white perch at most flash rates with a 0.2 m s ' flow rate, and at 120 and 300 flashes min ~ with 0.3 and 0.5 m s ~ flows. Spot had significant avoidance tot all flash rates at the 0.2 m s ~ flow, and for 300 and 600 flashes min ~ at water velocities of 0.3 and 0.5 m s ~. All species showed little avoidance of bubble curtains. Avoidances of 3 -58~ for white perch, 21-85% for spot and 9-81% for menhaden were obtained with the strobe light/bubblecurtain combinations. )f~ analyses indicated significant avoidance for most conditions at 0.2 and 0.5 m s ~ flows for spot and menhaden. White perch had significant awfidance for most cnndition~ at the 0.2 m s ~ flow, but no avoidance at 0.5 m s The strobe light and strobe light/bubble-curtain combinations elicited best avoidance results at flash rates of 300 min ~ or greater and low flow rates. Strobe lights show promise as a guidance system for estuarine fish. I N T R O D U C T I O N T h e u s e o f b e h a v i o r a l s y s t e m s in f i s h m a n a g e m e n t p r o g r a m s h a s r e c e i v e d i n c r e a s e d i n t e r e s t . L i g h t is a p r i m a r y s t i m u l u s t b r f i sh . B l a x t e r (1975) p r e s e n t e d 0165-7836/87/$03.50 © 1987 Elsevier Science Publishers B.V,