( Investigators have revealed that coral ...)Ongoing collapse of coral reef shark populations

Investigators have revealed that coral reef shark populations are in the midst of rapid decline, and that “no-take zones”—reefs where fishing is prohibited—do protect sharks, but only when compliance with no-take regulations is high. The findings, reported by William Robbins and colleagues at James Cook University and its ARC Centre of Excellence for Coral Reef Studies, appear in the December 5th issue of Current Biology.

Reef sharks are so-called apex predators on tropical coral reefs and are therefore of significant potential importance to the functioning of coral reef ecosystems. The reproductive biology of reef sharks makes them particularly vulnerable to fishing, but until now, there have been no studies of the response of these sharks to fishing pressure.

The new work focused on Australia’s Great Barrier Reef, which is widely considered to be one of the world’s least degraded, and best managed, reef systems. For balancing conservation with sustainable use, the Great Barrier Reef is regulated through an extensive series of management zones in which different areas are open to different levels of fishing. In their study, the researchers determined the status of two species of reef shark—the whitetip and grey reef sharks—by employing a unique combination of fisheries-independent abundance estimates and measurements of the survival and reproduction of individual sharks. Their findings show that reef shark abundance on reefs open to fishing are about ten times lower than on unfished reefs. Moreover, high reef shark abundance was only apparent on the most strictly enforced of the no-take zones, suggesting that even moderate levels of poaching can derail attempts to protect shark populations. These observations, coupled with population modeling showing ongoing, rapid declines in population size in fished areas, lead the authors to conclude that reef sharks are approaching “ecological extinction”—that is, becoming so rare that they can no longer per
'"/>

Source:Cell Press

Page: 1 2
Related biology news :

1. Discovering an ecosystem beneath a collapsed Antarctic ice shelf
2. Did humans cause ecosystem collapse in ancient Australia?
3. By 2048 all current fish, seafood species projected to collapse
4. Tsunami-damaged coral reefs should be left to recover naturally, say scientists
5. Hidden sponges determine coral reefs nutrient cycle
6. Marine conservation organizations team up to conduct Indonesia coral reefs assessment
7. Health of coral reefs detected from orbit
8. Scientists look to the Bahamas as a model for coral reef conservation
9. Tiny polyps gorge themselves to survive coral bleaching
10. Too much sugar not good for coral reefs
11. Sea corals trick helps scientists tag proteins