I think Eric has posted about this subsequent to this thread regarding the heritability of hook and line vulnerability. Researchers found that selection for vulnerability (breeding fish that were caught more than 3 or 4 times) increased vulnerability in subsequent generations. The opposite was true when fish, subjected to fishing pressure, were not caught and then selected for breeding. In the latter case, fish became increasingly difficult to catch and the effect was even greater. So I think everyone is aware that vulnerability to hook and line is a selectable trait and that harvest/culling introduces selection that makes fish in a BOW more difficult to catch over time.
These same researchers have/are investigating consequential effects along different paths of inquiry. One of the more interesting paths was on growth rate. It turns out that LMB that are less vulnerable to fishing grow the fastest and the researchers think that the same LMB actually consume less food. By their estimation, the specific energy requirements of maintenance metabolism for the low vulnerability line are 30% less than the high vulnerability line. This is remarkable. Selection for higher growth rate would also select for low vulnerability.
I am reminded of another post of Eric's which highlighted findings by texas researchers that found that in a typical BOW there are two populations of LMB where one population grows along one growth path and the other population grows along another. IIRC the slow growers tend to live longer and ultimately grow as large. While it may seem counterintuitive, it may be advantageous for quality of fishing for hatcheries to select for vulnerability only.
There has also been research on the ability of fish to learn hook avoidance. LMB, it turns out, are relatively slow to learn when compared with BG for example. Radabaugh found that individual bass also have different capacity to learn. Aside from hook avoidance, Radabaugh tested also for learning to take artificial feed. It would also be interesting to learn how the selective pressure of artificial feed learning may contribute to the selection for one or the other of the vulnerability lines. My intuition is that poor learners also tend to be the most vulnerable to hook and line.
Last edited by jpsdad; 01/08/21 11:32 AM.
