Publication: Marine Reserves and Bycatch
The following publication is available in full text at http://rmmc.eas.asu.edu/nrm/nrmVOLS/vol19/vol19-2/reit.pdf
NB: Author Siv Reithe was the winner of the 2002 IIFET Best Student Paper award
SIV REITHE
Norwegian College of Fishery Science
University of Troms´o
N-9037 Breivika
Norway
E-mail: sivr@nfh.uit.no
ABSTRACT - This paper explores the effects of using marine reserves as a measure to control bycatch that is of no commercial value, under different assumptions regarding the ecological interactions between targeted species and that taken as bycatch. Three cases are examined: (1) no ecological interactions between the two species, (2) targeted and bycatch species exist in a predator-prey relationship and (3) species compete. Targeted species is assumed to consist of two subpopulations that are discretely distributed in space, but linked through density dependent migration while bycatch species is assumed to consist of one uniformly distributed stock only. In each case the equilibrium stock levels of targeted and bycatch species, effort and harvest are numerically calculated and compared, assuming pure open access and open access in combination with a reserve. It is of special interest to identify circumstances that allows for a win-win situation, that is, both harvest of the targeted species and biomass of the bycatch species increase. It is shown that the ecological interactions between the two species influence the possibility of actually protecting the bycatch species through the use of a reserve, the possibility a win-win situation, and the issue of what patch to close.
KEY WORDS - Marine reserves, bycatch, multi-species interactions
The following publication is available in full text at http://rmmc.eas.asu.edu/nrm/nrmVOLS/vol19/vol19-2/reit.pdf
NB: Author Siv Reithe was the winner of the 2002 IIFET Best Student Paper award
SIV REITHE
Norwegian College of Fishery Science
University of Troms´o
N-9037 Breivika
Norway
E-mail: sivr@nfh.uit.no
ABSTRACT - This paper explores the effects of using marine reserves as a measure to control bycatch that is of no commercial value, under different assumptions regarding the ecological interactions between targeted species and that taken as bycatch. Three cases are examined: (1) no ecological interactions between the two species, (2) targeted and bycatch species exist in a predator-prey relationship and (3) species compete. Targeted species is assumed to consist of two subpopulations that are discretely distributed in space, but linked through density dependent migration while bycatch species is assumed to consist of one uniformly distributed stock only. In each case the equilibrium stock levels of targeted and bycatch species, effort and harvest are numerically calculated and compared, assuming pure open access and open access in combination with a reserve. It is of special interest to identify circumstances that allows for a win-win situation, that is, both harvest of the targeted species and biomass of the bycatch species increase. It is shown that the ecological interactions between the two species influence the possibility of actually protecting the bycatch species through the use of a reserve, the possibility a win-win situation, and the issue of what patch to close.
KEY WORDS - Marine reserves, bycatch, multi-species interactions