Journal Article

Harvest refugia in marine invertebrate fisheries: models and applications to the red sea urchin, Strongylocentrotus franciscanus

Botsford, L.W, Quinn, J.F, Wing, S.R

1993

Overview

Benthic marine invertebrates with planktonic larvae may exhibit Allee effects in reproduction or recruitment. Hydrodynamic considerations and experimental evidence suggest that species broadcasting gametes suffer greatly reduced fertilization efficiencies as densities decline. There is also evidence for some species, including the red sea urchin, that post-dispersal recruitment success declines at low densities of adults, if adults provide shelter from predators or other sources of mortality. Species displaying strong Allee effects may be susceptible to catastrophic population collapses with slight increases in mortality due to harvesting or natural causes. A simple two patch logistic model suggests that the establishment of a harvest refuge is necessary to prevent collapses and maintain sustainable catches at high levels of harvesting effort. A more detailed, age structured model based on the biology of the red sea urchin, Strongylocentrotus franciscanus produces similar results. Effects of harvesting strategies are sensitive to Allee effects caused by both fertilization efficiency and the disruption of adult spine canopies. Theoretical requirements for the size and spacing of marine reserves depends upon the dispersal abilities of the target species. Multiple reserves, spaced more closely than the average larval dispersal distance, appear to be an effective and conservative strategy for maintaining healthy populations and sustainable levels of harvest.

• Publisher: American Society of Zoologists,Society for Integrative and Comparative Biology
• Subject: ADMINISTRACION PESQUERA / AMBIENTE MARINO / Animal and plant ecology / Animal, plant and microbial ecology / Animals / Biological and medical sciences / CONSERVACION DE LA NATURALEZA / CONSERVATION DE LA NATURE / COSECHA / Demecology / DENSIDAD DE LA POBLACION / DENSITE DE POPULATION / EDIBLE SPECIES / ESPECE / ESPECIES / Fertilization / fisheries management / FISHERY MANAGEMENT / Fundamental and applied biological sciences. Psychology / GESTION DES PECHES / HARVESTING / Larvae / Marine / MARINE ENVIRONMENT / MATHEMATICAL MODELS / Metapopulation ecology / MILIEU MARIN / MODELE MATHEMATIQUE / MODELOS MATEMATICOS / Mortality / NATURE CONSERVATION / overfishing / PECHE AUX MOLLUSQUES ET CRUSTACES / PESCA DE MARISCOS / POPULATION DENSITY / Protozoa. Invertebrata / RECOLTE / Refuge habitats / REPRODUCCION SEXUAL / REPRODUCTION SEXUEE / Sea urchins / SEXUAL REPRODUCTION / SHELLFISH FISHERIES / SPECIES / STRONGYLOCENTROTUS / Sustainable agriculture / The Crisis in Invertebrate Conservation / Wildlife habitats / Young animals