Morse and Able: Distribution and life history of Scophthalmus aquosus 



677 



44 



42" 



40° 



38 - 



36" 

 N 



W 76 



Figure 1 



Sampling area for planktonic larvae in the northeastern United States, 

 based on NMFS/MARMAP sampling stations, and important localities that 

 are mentioned in the text. Typical sampling array of stations shown by 

 dots. See Table 1 for further details. Middle Atlantic Bight = subareas 1- 

 6, Georges Bank = subarea 7. 



length-dependent correction was made to the catches 

 to account for differences in day, night, and twilight 

 catchability (Morse, 1989). Preliminary analysis of 

 larval occurrence and bottom depth revealed that 

 larvae are restricted to waters <100 m deep; there- 

 fore, only stations <100 m deep were used for calcu- 

 lating larval catch statistics. In addition, larvae were 

 extremely rare north of 42°N (caught at only 24 of 

 2,470 stations); therefore, this area was not consid- 

 ered in the analysis. Mean catches of windowpane 

 larvae were calculated by using the Delta method of 

 Pennington (1983). Graphical plots of the distribu- 

 tion and abundance of larvae are presented as the 

 average catch per 100 m 2 within 625 km 2 blocks of 

 the survey area. Eggs and larvae were sampled at 

 estuarine and inner continental shelf sites during 

 1972-75 (Table 1; Fig. 2). These sites included the 

 Mullica River (water depth 1.8-10.6 m), Great Bay 

 (1.5-10.7 m), Little Egg Inlet (4.6-8.8 m), in the vi- 

 cinity of sand ridges outside Little Egg Inlet (3.0- 

 16.5 m), and farther offshore of the sand ridge sites 



( 16.2-23.5 m). At continental shelf sites, 

 15-minute tows were made at the sur- 

 face ( 1.0-m plankton net, 0.5-mm mesh), 

 at midwater and bottom depths (0.5-m 

 plankton net, 0.5-mm mesh), and as ob- 

 lique tows (bongo samplers, 0.2-m or 

 0.36-m diameter, 0.5-mm mesh). In the 

 estuary tow times were reduced to 5- 

 10 minutes but the same three nets 

 were used at the same depths. Esti- 

 mates of water volume filtered were de- 

 termined with a flowmeter. 



Juveniles and adults 



Juvenile and adult windowpane (2-48 

 cm TL ) were collected during the semi- 

 annual bottom trawl surveys of NMFS, 

 Northeast Fisheries Science Center, 

 from 1982 to 1991 (Azarovitz, 1981), 

 during inshore surveys of the Common- 

 wealth of Massachusetts Division of 

 Marine Fisheries from 1988 to 1992 

 (Howe et al. 1 ), and during the New Jer- 

 sey Bureau of Marine Fisheries surveys 

 from 1988 to 1992 (Byrne 2 - 3 ). All three 

 surveys used a stratified random-sam- 

 pling design, and strata were based on 

 depth and latitude. NMFS spring and 

 fall surveys sampled about 350 stations 

 during a 6—8 week period from Cape 

 Fear, North Carolina, to Nova Scotia in 

 depths from 3 to 366 m. Commonwealth 

 of Massachusetts Division of Marine 

 Fisheries sampled approximately 80-90 stations 

 within 55-m depths in state coastal waters during 

 May and September. New Jersey Bureau of Marine 

 Fisheries sampled 25-39 stations in state coastal wa- 

 ters within 27 m of water every 6-10 weeks. 



For the analysis of NMFS bottom trawl and plank- 

 ton surveys, the sampling area was divided into seven 

 subareas (Fig.l). Data from monthly collections of 

 larval, juvenile, and adult windowpane near Little 

 Egg Inlet, New Jersey, during 1973-74 (Fig. 2) were 



Howe, A. B., D. Maclsaac, B. T. Estrella, and F. J. Germano 

 Jr. 1979. Fishery resource assessment, coastal Massa- 

 chusetts. Completion Rep., Massachusetts Div. Mar. Fish., 

 Commercial Fish. Res. Div. Project No. 3-287-R-l, 34 p. 

 Byrne, D. M. 1988. Inventory of New Jersey's coastal 

 waters. New Jersey Dep. Environmental Protection, Div. 

 Fish, Game, Wildl. Mar. Fish. Admin., Bur. Mar. Fish. Annual 

 Rep. to U.S. Fish. Wildl. Serv. 



Byrne, D. M. 1990. Inventory of New Jersey's coastal 

 waters. NJDEP, Div. Fish., Game, Wildl, Mar. Fish. Admin., 

 Bur. Mar. Fish. Annual Rep. to U.S. Fish. Wildl. Serv. 



