Publisher :
Place of publication :
Publication year : 2003
Thematic : Marine Protected Areas
Language : English
Note
Marine reserves are quickly gaining popularity as a management option for
marine conservation, fisheries, and other human uses of the oceans. Despite the popularity
of marine reserves as a management tool, few reserves appear to have been created or
designed with an understanding of how reserves affect biological factors or how reserves
can be designed to meet biological goals more effectively (e.g., attaining sustainable fish
populations). This shortcoming occurs in part because the many studies that have examined
the impacts of reserves on marine organisms remain isolated examples or anecdotes; the
results of these many studies have not yet been synthesized. Here, I review the empirical
work and discuss the theoretical literature to assess the impacts of marine reserves on
several biological measures (density, biomass, size of organisms, and diversity), paying
particular attention to the role reserve size has in determining those impacts. The results
of 89 separate studies show that, on average, with the exception of invertebrate biomass
and size, values for all four biological measures are significantly higher inside reserves
compared to outside (or after reserve establishment vs. before) when evaluated for both
the overall communities and by each functional group within these communities (carnivorous
fishes, herbivorous fishes, planktivorous fishes/invertebrate eaters, and invertebrates).
Surprisingly, results also show that the relative impacts of reserves, such as the proportional
differences in density or biomass, are independent of reserve size, suggesting that the effects
of marine reserves increase directly rather than proportionally with the size of a reserve.
However, equal relative differences in biological measures between small and large reserves
nearly always translate into greater absolute differences for larger reserves, and so larger
reserves may be necessary to meet the goals set for marine reserves.
The quality of the data in the reviewed studies varied greatly. To improve data quality
in the future, whenever possible, studies should take measurements before and after the
creation of a reserve, replicate sampling, and include a suite of representative species.
Despite the variable quality of the data, the results from this review suggest that nearly
any marine habitat can benefit from the implementation of a reserve. Success of a marine
reserve, however, will always be judged against the expectations for that reserve, and so
we must keep in mind the goals of a reserve in its design, management, and evaluation.
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Keywords : Hystrix crassispinis
Encoded by : Pauline Carmel Joy Eje
