Changes in Fish Assemblages following the Establishment of a Network of No-Take Marine Reserves and Partially-Protected Areas

Brendan P Kelaher,Matthew J Rees,Melinda A Coleman,Andrew R Davis,Allison Broad,Alan Jordan,Arga Chandrashekar Anil

doi:10.1371/journal.pone.0085825

Brendan P Kelaher, Matthew J Rees + Show 5 more

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https://doi.org/10.1371/journal.pone.0085825

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Abstract

Networks of no-take marine reserves and partially-protected areas (with limited fishing) are being increasingly promoted as a means of conserving biodiversity. We examined changes in fish assemblages across a network of marine reserves and two different types of partially-protected areas within a marine park over the first 5 years of its establishment. We used Baited Remote Underwater Video (BRUV) to quantify fish communities on rocky reefs at 20–40 m depth between 2008–2011. Each year, we sampled 12 sites in 6 no-take marine reserves and 12 sites in two types of partially-protected areas with contrasting levels of protection (n = 4 BRUV stations per site). Fish abundances were 38% greater across the network of marine reserves compared to the partially-protected areas, although not all individual reserves performed equally. Compliance actions were positively associated with marine reserve responses, while reserve size had no apparent relationship with reserve performance after 5 years. The richness and abundance of fishes did not consistently differ between the two types of partially-protected areas. There was, therefore, no evidence that the more regulated partially-protected areas had additional conservation benefits for reef fish assemblages. Overall, our results demonstrate conservation benefits to fish assemblages from a newly established network of temperate marine reserves. They also show that ecological monitoring can contribute to adaptive management of newly established marine reserve networks, but the extent of this contribution is limited by the rate of change in marine communities in response to protection.

Highlights

Human activities, such as catchment development, overfishing, pollution and maritime industries, have degraded marine and estuarine environments [1,2]
Contrasts were included to compare sanctuary zones (SZ) with fished areas (FA) and habitat protection zones (HPZ) with general use zones (GUZ). p-F = pseudo F ratio generated by PERMANOVA. doi:10.1371/journal.pone.0085825.t002
6.03 12.37 0.14 0.37 0.54 0.63 1.38 (c) Labridae (d) Monacanthidae df Contrasts were included to compare sanctuary zones (SZ) with fished areas (FA) and habitat protection zones (HPZ) with general use zones (GUZ). p-F = pseudo F ratio generated by PERMANOVA. doi:10.1371/journal.pone.0085825.t003

Summary

Introduction

Human activities, such as catchment development, overfishing, pollution and maritime industries, have degraded marine and estuarine environments [1,2]. Many published studies have evaluated the responses of marine ecosystems to reserve establishment [5] These include highlighting the types of species that do and do not benefit A limitation of most marine reserves is that they are not large enough to be completely self-sustaining because their size is less than the average dispersal distance of key species [15]. This issue can be resolved by establishing much larger marine reserves, socio-economic pressures are likely to prevent this, on densely populated coasts. Published data on changes in marine communities across marine reserve networks is limited relative to research on individual marine reserves and rigorous empirical tests of theoretical models optimizing marine reserve network designs are still in their infancy [4,21]

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