Marine reserves: the best strategy for maximizing reproductive biomass in a heavily targeted reef fish

Recruitment overfishing (the reduction of a spawning stock past a point at which the stock can no longer replenish itself) is a common problem which can lead to a rapid and irreversible fishery collapse. Averting this disaster requires maintaining a sufficient spawning population to buffer stochasti...

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Main Authors: Taylor, B., McIlwain, Jennifer, Kerr, A.
Format: Journal Article
Published: Public Library of Science 2012
Online Access:http://hdl.handle.net/20.500.11937/19074
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author Taylor, B.
McIlwain, Jennifer
Kerr, A.
author_facet Taylor, B.
McIlwain, Jennifer
Kerr, A.
author_sort Taylor, B.
building Curtin Institutional Repository
collection Online Access
description Recruitment overfishing (the reduction of a spawning stock past a point at which the stock can no longer replenish itself) is a common problem which can lead to a rapid and irreversible fishery collapse. Averting this disaster requires maintaining a sufficient spawning population to buffer stochastic fluctuations in recruitment of heavily harvested stocks. Optimal strategies for managing spawner biomass are well developed for temperate systems, yet remain uncertain for tropicalfisheries, where the danger of collapse from recruitment overfishing looms largest. In this study, we explored empirically and through modeling, the role of marine reserves in maximizing spawner biomass of a heavily exploited reef fish, Lethrinus harak around Guam, Micronesia. On average, spawner biomass was 16 times higher inside the reserves compared with adjacent fished sites. Adult density and habitat-specific mean fish size were also significantly greater. We used these data in an age-structured population model to explore the effect of several management scenarios on L. harak demography. Under minimum-size limits, unlimited extraction and all rotational-closure scenarios, the model predicts that preferential mortality of larger and older fish prompt dramatic declines in spawner biomass and the proportion of male fish, as well as considerable declines in total abundance. For rotational closures this occurred because of the mismatch between the scales of recovery and extraction. Our results highlight how alternative management scenarios fall short in comparison to marine reserves in preserving reproductively viable fish populations on coral reefs.
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spelling curtin-20.500.11937-190742017-09-13T13:46:48Z Marine reserves: the best strategy for maximizing reproductive biomass in a heavily targeted reef fish Taylor, B. McIlwain, Jennifer Kerr, A. Recruitment overfishing (the reduction of a spawning stock past a point at which the stock can no longer replenish itself) is a common problem which can lead to a rapid and irreversible fishery collapse. Averting this disaster requires maintaining a sufficient spawning population to buffer stochastic fluctuations in recruitment of heavily harvested stocks. Optimal strategies for managing spawner biomass are well developed for temperate systems, yet remain uncertain for tropicalfisheries, where the danger of collapse from recruitment overfishing looms largest. In this study, we explored empirically and through modeling, the role of marine reserves in maximizing spawner biomass of a heavily exploited reef fish, Lethrinus harak around Guam, Micronesia. On average, spawner biomass was 16 times higher inside the reserves compared with adjacent fished sites. Adult density and habitat-specific mean fish size were also significantly greater. We used these data in an age-structured population model to explore the effect of several management scenarios on L. harak demography. Under minimum-size limits, unlimited extraction and all rotational-closure scenarios, the model predicts that preferential mortality of larger and older fish prompt dramatic declines in spawner biomass and the proportion of male fish, as well as considerable declines in total abundance. For rotational closures this occurred because of the mismatch between the scales of recovery and extraction. Our results highlight how alternative management scenarios fall short in comparison to marine reserves in preserving reproductively viable fish populations on coral reefs. 2012 Journal Article http://hdl.handle.net/20.500.11937/19074 10.1371/journal.pone.0039599 Public Library of Science fulltext
spellingShingle Taylor, B.
McIlwain, Jennifer
Kerr, A.
Marine reserves: the best strategy for maximizing reproductive biomass in a heavily targeted reef fish
title Marine reserves: the best strategy for maximizing reproductive biomass in a heavily targeted reef fish
title_full Marine reserves: the best strategy for maximizing reproductive biomass in a heavily targeted reef fish
title_fullStr Marine reserves: the best strategy for maximizing reproductive biomass in a heavily targeted reef fish
title_full_unstemmed Marine reserves: the best strategy for maximizing reproductive biomass in a heavily targeted reef fish
title_short Marine reserves: the best strategy for maximizing reproductive biomass in a heavily targeted reef fish
title_sort marine reserves: the best strategy for maximizing reproductive biomass in a heavily targeted reef fish
url http://hdl.handle.net/20.500.11937/19074