The conservation of sharks and manta rays in coral reefs

An interesting study published in Nature ecology & evolution has done a retrospective on the issue

by Lorenzo Ciotti
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The conservation of sharks and manta rays in coral reefs
© Dan Kitwood / Staff Getty Images

The coral reef is a typical formation of tropical seas and oceans, composed of biogenic underwater rock formations formed and increased by the sedimentation of the calcareous skeletons of corals, polypoid animals belonging to the class Anthozoa, phylum Cnidaria. This is why reefs are one of the most important organisms for biodiversity. Unfortunately, these ecosystems are very fragile and are threatened, directly or indirectly, by human activity. Trawling and anchors can significantly damage them, while the indiscriminate use of poison to stun fish and the aquarium trade has caused in some areas a patchy die-off of the octopuses found in the area.

But what is the conservation status of sharks and manta rays in coral reefs?

Shark
Shark© Carl Court / Staff Getty Images
 

The study Directed conservation of the world's reef sharks and rays, published in the Nature ecology & evolution, shared an interesting abstract on the issue.

The researchers explain: "We showed that the conservation benefits were primarily for reef-associated sharks, which were twice as abundant in fully protected areas compared to areas open to fishing. However, the conservation benefits were greater in large protected areas incorporating distinct coral reefs the same benefits were not evident for rays or wide-ranging sharks which are both economically and ecologically important but also threatened with extinction.

We have shown that conservation benefits from areas completely protected areas have almost doubled when incorporated into areas of effective fisheries management, highlighting the importance of a mixed management approach of both effective fisheries management and well-designed fully protected areas to conserve tropical elasmobranch assemblages globally of sharks are declining worldwide, with serious ecological and economic consequences.

Fisheries management and marine protected areas have both been heralded as solutions. However, the effectiveness of MPAs alone is questionable, particularly for globally threatened sharks and rays, with little known about how fisheries management and MPAs interact to conserve these species. Here we use a global survey dedicated to coral reef elasmobranchs to evaluate 66 fully protected areas within a fisheries management series. regimes in 36 countries."