SCIENCE SUPPORT
e importance of large female sh within a stock biomass was rst reported well over 100 years ago (Hjort 1914) but it is only relatively recently that scientists are starting to understand and fully appreciate how important such sh actually are.
In a great many sh species, including European bass, BOFFFFs produce more and very often larger eggs compared to smaller but mature sized sh and once hatched, the o spring of BOFFFFs frequently display faster growth and better survival rates.
As can be seen above, a European bass that is 80cm in length (approximately 5kgs) produces nearly three times as many eggs as a sh just 20cm shorter and over seven times as many as a sh of 40cm (approximately 0.7kgs). Moreover, BOFFFFs have a tendency towards an earlier and longer spawning season and since large sh are more robust than smaller sh, BOFFFFs can also spawn in locations that smaller sh can’t. us, BOFFFFs help to ensure individual reproductive success in environments that other sh may not be able to reproduce in.
Similarly, BOFFFFs can survive periods that aren’t conducive to successful reproduction and in doing so, enhance recruitment when conditions return to normal. is is termed “the storage e ect”. It is also known that removing BOFFFFs, by using non-selective
shing methods for example, destabilizes shed populations and increases susceptibility of collapse even after shing e ort is later reduced, further illustrating BOFFFF importance to populations.
So, one can see why it is critically important that as many BOFFFFs remain part of the spawning-stock biomass as possible in order to maximise recruitment.
A Bass Fishery Management Plan would do well to take into account that BOFFFFs are an important element of the stock biomass that can bene t bass anglers and all shers alike.
References:
■ Hixon et al, ICES Journal of Marine Science, Volume 71, Issue 8, October 2014, Pages 2171–2185
■ Lavin et al, Proc Biol Sci. 2021 Mar 10;288
■ *ICES/CIEM advice on sea bass for areas North Sea, English Channel, Irish Sea, Bristol Channel, Celtic Sea 2021
Policy Lab is seeking what they term 'Lived Experiences' from recreational and commercial fishermen, so if you have been fishing for bass for a number of years, here is your chance to tell your story. Why do you fish for bass, have you noticed any changes in the numbers or sizes of the bass that you catch and what are your hopes for the Bass Fisheries Management Plan and for the future of bass fishing?
You can email your lived experiences to Policy Lab at bass@policylab.gov.uk