The fish community of Rat Cove, Otsego Lake, sumn,er 1997

Transcription

1 74 The fsh communty of Rat Cove, Otsego Lake, sumn,er 1997 Mcah ngalls ABSTRACT n Rat cove thrteen speces of fsh were documented durng the summer of 1997: alewfe (Alosa pseudoharengus), yellow perch (Percaflavenscens), brown bullhead (ctalurus nebulosus), rock bass (Amblopltes rupestrs), redbreast sunfsh (Lepoms aurtus), bluegll (Lepoms macrochrus), pumpknseed (Lepoms gbbosus), common carp (Cyprnus carpo), whte sucker (Catostomus commerson), European rudd (Scardnus erythrophthalymus), largemouth bass (Mcropterus salmodes), chan pckerel (Esox nger) and golden shner (Notemgonus crysoleucas). The majorty of all of the fsh caught durng the course of the study were alewves (makng up 54.5% of the communty). Although no drect measures were taken to study the spawnng of the fsh speces durng ths study, t was observed that fsh populatons tended to reach a defntve apex and then decrease contnuously n correlaton to ther presupposed spawnng season. Nearly all ofthe fsh speces were found n much smaller numbers by early August followng a rapd decrease n populaton at the end of July, wth the excepton of the golden shners whch slghtly ncreased at the begnnng of August from ther low on the 24 of July. Some of the fsh of Rat cove showed a lower average length than the supposed average for New York State fresh-waters n some speces. NTRODUCTON Rat Cove s a lttoral embayment along the southwestern sde of Otsego Lake. The objectve of ths survey was to provde a composte of the fsh fauna present n Rat Cove over a gven season, notng the makeup of the communtes, domnance of speces, relatve szes offsh wthn each speces, and the fluctuaton n the populatons of each fsh speces relatve to the gven season. Perhaps, wth further study Rat Cove may prove ndcatve of other lttoral embayments n Otsego lake. METHODS AND MATERALS The survey was conducted from 9 June untl 7 August 1997 approxmately fve days per week. Fsh were collected usng a fve-foot trap net wth a ffty-foot lead whch was extended from shore out to 55 feet n the lttoral zone of Rat Cove, n accordance wth the standard trap net usage (Foster, 1996). The trap net was set at the begnnng of every week and then checked at 24 hour ntervals for the followng four days and removed at the end of every week. Lengths were measured to the nearest mllmeter. All were returned to the water, except for the alewves whch New York Academy of Scence Hgh School Research Tranee, SUumer Present afflaton: Cooperstown Central School.

2 75 were taken to the Bologcal Feld Staton where they were measured and weghed. Addtonally, 300 scale samples were taken from alewves. Scales were also taken from a number of other fsh speces, at random, over the course of the study. The scales were then studed by use of a mcrofsche reader to ascertan relatve age and growth patterns ofthe speces nvolved. RESULTS The fsh communty of Rat Cove s domnated by alewves, followed by bluegll, pumpknseed, brown bullhead, golden shner, yellow perch, rock bass, redbreast sunfsh whte suckers, European rudd, long ear sunfsh, common carp, chan pckerel, and large mouth bass, n order of domnance (Fgure ). Catch per unt effort of each of these speces s gven n Fgure 2 (note that y-axs range vares among speces). Domnaton by the alewfe, a relatvely new member of Otsego's fsh communty, s consstent wth past fndngs (Warner et a., 1997). REFERENCES Foster, lr The fsh fauna ofotsego Lake. n 28 th Ann. Rept. (1995) SUNY Oneonta Bo. Fld. Sta., SUNY Oneonta. pp Warner, D., L. Rudstam and W.N. Harman An estmaton of the densty, abundance, bomass and speces composton of the Otsego Lake pelagc fsh communty and zooplankton and alewfe phosphorus regeneraton. n 29 th Ann. Rept. (1996). SUNY Oneonta Bo. Fld. Sta., SUNY Oneonta. pp

3 76 LMB 10.07%j PC 0.10% CARP 0.17% RUDD W.22%) RB;S(b.91;:))- RB (1.57%) YP (2.13%) GS (2.23%). BB (2.64%).'. LMB= Largemouth Bass PC= Pckerel CARP= Carp RUDD= European Rudd WS= Whte Sucker RBSF= Redbreast Sunfsh RB= Rock Bass YP= Yellow Perch GS= Golden Shner BB= Brown Bullhead PKSD= Pumpknseed BG= Bluegll ALE= Alewfe PKSD (12.11%)----. ALE (54.53%) BG (22.73%)- Fgure 1. Relatve abundance of fsh n Rat Cove, Otsego Lake, collected throughout summer, 1997.

4 77, Brown Bullhead Alewfe _ ---l 'l, 0 10! ; \ "0,," \ 1 / \\. 300 \ ' J' \ r 1 ) \ o /16 06/ /0? / date of catch. 0 : '0,,". 06/09 06/16 00/ /07 07/ /04 daleolcalch Bluegll Golden Shlnner 160 _ ; '0 " 60.1, /. o /.?,. ', /16 06/23 06/ r21 071'28 OBfOl dateofc<'jlch!\ "40 30 "0 l ; 10 j '"' o 06/19 061'26 07/ t17 07/ daleo/catch Fgure 2. Daly catch of each fsh speces n Rat Cove, Otsego Lake, collected throughout summer, 1997.

5 78 Pumpknseed Yellow Perch r! \! \ /1< /004 date Jf catch 1: 14 [ l' 6 ''\ /, \ 2!, " o /23 08/30 07/ \ dele or celch / J Redbreast Sunfsh -, Rock Bass 16 J \04, : 2 _ o _ / '' / /30 08/08 dat! or catch 16 l' l 8 ".",. 2! \.,, o / /30 07/07 07/loll dale or catch ' _._----_." j \ Fgure 2 (contnued). Daly catch of each fsh speces n Rat Cove, Otsego Lake, collected throughout summer, 1997.

6 79, , Carp Largemouth Bass 3, 2! 2 \! 1 +a o : -, --l 06;1)9 06/ ;1)9 07/ /19 07/ /03 Pckerel Whle Sucker , 4 ' 3 2 " " ',:,,:J 2 ", " " ; _. 07/04 '. 07/ /25 08/01 06/09 06/16 06/23 06/30 '' J Fgure 2 (contnued). Daly catch of each fsh speces n Rat Cove, Otsego Lake, collected throughout summer, 1997.