Sammanfattning

We hypothesize that size at hatching strongly affects population dynamics of cannibalistic fish species and is a crucial determinant of how populations respond to selective removal of large individuals (harvesting). We use a mechanistic mathematical model to study the relation between hatching size and response to harvesting mortality, using Eurasian perch (Perca fluviatilis) as a model organism. We show how hatching size determines dynamics through its effect on the relative strength of cannibalistic mortality and resource competition as mechanisms of population regulation. In populations with intermediate and large hatching size, cannibalistic mortality is an important determinant of population dynamics. and harvesting destabilizes population dynamics. When hatching size is small, population stability is less sensitive to this type of harvesting. Populations hatching at small size are regulated by competition, and harvesting large individuals affects such populations less. Harvesting can also induce the growth of very large individuals, absent in unharvested populations. Our results show that harvesting in cannibalistic lake fish populations can strongly alter Population dynamics in ways that can only be anticipated on the basis of mechanistic knowledge about how populations are regulated.

Publicerad i

Canadian Journal of Fisheries and Aquatic Sciences
2010, Volym: 67, nummer: 2, sidor: 401-416
Utgivare: NATL RESEARCH COUNCIL CANADA-N R C RESEARCH PRESS

SLU författare

• Byström, Pär

  • Institutionen för vattenbruk, Sveriges lantbruksuniversitet
    

Globala målen

SDG14 Bevara och nyttja haven och de marina resurserna på ett hållbart sätt för en hållbar utveckling


UKÄ forskningsämne

Fisk- och akvakulturforskning
Miljö- och naturvårdsvetenskap


Publikationens identifierare

DOI: https://doi.org/10.1139/F09-157

Permanent länk till denna sida (URI)

https://res.slu.se/id/publ/48611