FISHERY BULLETIN: VOL. 80, NO. 4 



ues are all quite low (Fig. 6F). Even with these 

 low values, there is an obvious trend; the higher 

 values occur between the smaller individuals of 

 these two predators which reflects the depen- 

 dance of small silver hake and haddock on crus- 

 tacean prey. 



Silver Hake — Ocean Pout 



The diets of silver hake and ocean pout are 

 mutually exclusive so that there is an extremely 

 small degree of diet overlap (Fig. 6G). The only 

 prey that they share in common are amphipods, 

 but again, this is at a very low level. 



Silver Hake — American Plaice 



Silver hake and American plaice show very 

 low levels of dietary overlap (Fig. 7A). Despite 



the lack of diet similarity, a pattern does emerge 

 when comparing these two predators. The larger 

 size classes of both species show virtually no over- 

 lap, while what similarity does exist occurs be- 

 tween silver hake and American plaice <40 cm. 

 The diet of these larger individuals is quite spe- 

 cific, fish for silver hake and echinoderms for 

 American plaice, so little overlap is to be ex- 

 pected, while the smaller individuals of both spe- 

 cies prey on invertebrates. 



Silver Hake — Witch Flounder 



Silver hake and witch flounder share little 

 prey in common with resulting low levels of diet 

 overlap. The only exception to these low levels is 

 a high peak (66% and 67%) between 16-20 cm (size 

 class 4) silver hake and 11 -20 cm (size classes 3-4) 

 witch flounder (Fig. 7B). A single prey species, 



PLEURONECTIFORMES 



fV-OU* 



15 CM LENGTH CLASSES) 



Figure 7.— Three dimensional plot of silver hake and selected pleuronectiform fishes. 



756 



