Biological Oceanography

(ff) #1

17.14) and thus have better survival chances. For some fish and some capture
techniques, individuals exceeding a size threshold can be returned to the sea,
surviving temporary capture, but for many the ascent to the surface or crushing in
trawls is fatal.


Fig. 17.14 Relationships for black rockfish (Sebastes melanops) between the ages of
females releasing larvae and (a) larval growth rate in length, (b) growth rate in mass,
and (c) median time to starvation when held without food. Similar relationships are
found for the size of oil globules in the larval yolk sac.
(After Berkeley et al. 2004.)


(^) Often the real issue involving growth is to know the size and age structure of the
stock. Fishing usually removes the larger, older fish from the population, partly
because they are sought by fishers and, thus, usually favored by the technology
chosen. They are, of course, less numerous even in the absence of fishing. Thus, onset

Free download pdf