Steves et al.: Settlement and nursery habitats for demersal fishes 



179 



1 



< 



E. microstomus 



80 100 



Fall and winter settling fish 

 S. aquosus C. striata 



50 100 



100 



200 



300 



Standard length (mm) 



Figure 6 



Length frequencies by cruise of four species (Etropus microstomua, Scophthalmus aquosus, Centropristis striata, and Macrozoarces 

 americanus) that settled to the shelf between midfall and winter. Plots for each species are ordered from top to bottom according to 

 the order of the 10 cruises (see Table 1 for cruise dates). Abundance on each cruise was standardized to the number offish collected 

 during 63 5-min tows (21 stations with 3 tows each). 



Discussion 



Many commercially and ecologically important spe- 

 cies of demersal fishes in the NYB settle onto the 

 continental shelf throughout the course of the year. 

 In some cases settlement densities on the shelf may 

 rival those of nearshore and estuarine species. For 

 example, at some stations yellowtail flounder {P. fer- 

 rugineus) was found to have settlement densities 

 as high as the long-term average for a congeneric 

 estuarine species, plaice (Pleuronectes platessa), at 



approximately one per m- (Modin and Phil, 1994). 

 Yet given the large areal extent of P. ferrugineus set- 

 tlement on the shelf, its relative total abundance is 

 potentially much larger. Similarly dense settlement 

 may occur within portions of the shelf environment 

 for other species such as Merluccius bilinearis. Even 

 for those species collected in relatively low numbers, 

 the large areas of NYB in which they settle suggests 

 that total numbers are substantial. 



Evidence that settlement does occur on the shelf 

 is from two sources. The minimum size of collected 



