Sharks play a fundamental role in coral health say scientists studying remote reefs off Australia, September 19, Overfishing of the marine predators is also increasing reef vulnerability to global warming and disasters. File photo of an Australian marine unit officer seizing shark fins from an illegal fishing vessel off the north coast. SYDNEY AFP — Scientists studying remote reefs off Australia said Thursday sharks played a fundamental role in coral health, with overfishing of the marine predators increasing reef vulnerability to global warming and disasters. A research team, led by Mark Meekan from the Australian Institute of Marine Sciences, studied the impact of sharks at the Rowley Shoals and Scott Reefs some kilometres miles off Australia's north-west coast over a period of 10 years. The study compared the impacts of cyclones and bleaching events on the marine-protected Rowley Shoals, where fishing is banned, with the neighbouring Scott Reefs, where Indonesian fishermen are permitted to hunt sharks.
Coral reefs around the world are threatened both by natural and anthropogenic factors, with tourism having an important role in the latter. Direct impacts in coral reefs are related with badly managed tourism activities, such as snorkeling, diving, and sailing. Indirect impacts of tourism related to waste, pollution, and unsustainable uses of natural resources are also critical. Along the coastline of the Great Barrier Reef, tourism is a major industry with up to two million visitors contributing greatly to local, regional, and national development. However, unlike other coral reef destinations around the world, in this World Heritage site, appropriate tourism management strategies have changed tourism from a threat in the past to a strong conservation ally in the present. In , tourism operators started collecting coral observations during their visits to the Great Barrier Reef and reporting them for analysis by the Marine Park Managers and scientific researchers.
An international fleet of thousands of longliners now fish the world's oceans, landing millions of tons of tuna and swordfish every year. Longlining, an ultra-efficient practice developed after World War II by Japanese fishermen, deploys up to 60 miles of baited hooks across vast expanses of the Atlantic ocean where bluefin tuna migrate. In addition to catching swordfish and tuna, longlining tends to catch other, untargeted species like sharks and sea turtles.
Billions of people around the world rely on fish as a source of protein and fishing is the principal livelihood of millions. Maintaining the balance of exquisite life in our oceans is just as critical to life on land. But many of the world's fisheries have been pushed beyond their biological limits.