In a study announced today by the Wildlife Conservation Society* (WCS) at the International Coral Reef Initiative** (ICRI) meeting in Thailand, researchers show that some coral reefs located off East Africa are unusually resilient to climate change. The high resilience is believed to be caused by geophysical factors in combination with improved fisheries management in these waters.

After studying corals off the coast of Tanzania, researchers found that these coral reefs has made an incredibly speedy recovery from the 1998 bleaching event that wiped out up to 45 percent of the region’s corals. The authors of the study attribute the swift recovery to a combination of reef structure and reef management.

Compared to many other coral reefs around the world, Tanzania’s reefs are used to considerable variations in both current and water temperature which has turned these reefs into an unusually complex web of different coral species. This bio-diverse ecosystem includes several different species known to quickly re-colonize an area after a bleaching incident.

The authors of the study believe that reefs in other parts of the world subjected to similarly diverse environmental conditions might have the same high ability to recover from large-scale climatic and human disturbances. The study provides additional evidence that such “super reefs” can be found in the triangle from Northern Madagascar across to northern Mozambique to southern Kenya and the authors suggest that these reefs should be a high priority for conservation efforts since they may come to play an important global role in the future recovery of coral reefs worldwide.

“Northern Tanzania’s reefs have exhibited considerable resilience and in some cases improvements in reef conditions despite heavy pressure from climate change impacts and overfishing,” says Dr. Tim McClanahan***, the study’s lead author. “This gives cause for considerably more optimism that developing countries, such as Tanzania, can effectively manage their reefs in the face of climate change.”

The study also stresses the impact of direct management measures in Tanzania, including closures to commercial fishing. Algae is known to easily smother corals, but researchers found how areas with fishery closures contained a rich profusion of algae eating fish species that kept the corals clean. The few sites without any management measures remained degraded, and in one of them the population of sea urchins had exploded. Sea urchins feed on corals and can therefore worsen the problem for an already suffering reef.

The study has been published in the online journal Aquatic Conservation: Marine and Freshwater Ecosystems.

Authors of the study include Tim McClanahan and Nyawira Muthiga of the Wildlife Conservation Society, Joseph Maina of the Coral Reef Conservation Project, Albogast Kamukuru of the University of Dar es Salaam’s Department of Fisheries Science and Aquaculture, and Saleh A.S. Yahna of the University of Dar es Salaam’s Institute of Marine Sciences and Stockholm University’s Department of Zoology.

* The Wildlife Conservation Society is an institutional partner to ICRI and is actively conserving tropical coral reef species in priority seascapes in Belize, Indonesia, Papua New Guinea, Fiji, Kenya and Madagascar. Along with monitoring reefs, WCS also trains of park staff in protected areas.

** The International Coral Reef Initiative (ICRI) is a global partnership among governments and organizations working to stop and reverse the degradation of coral reefs and related ecosystems. This ICRI General Meeting was convened by the joint Mexico – United States Secretariat.

*** Dr. McClanahan’s research regarding ecology, fisheries, climate change effects, and management of coral reefs at key sites throughout the world is supported by the Western Indian Ocean Marine Science Association (WIOMSA) and The Tiffany & Co. Foundation.

According to the BBC, conservationists are increasingly concerned over the future for the Bangladesh river dolphins since they are now threatened not only by pollution, over-fishing, accidental deaths caused by fishing nets, and shortage of prey, and but also by declining freshwater supplies. The situation is especially serious for the Ganges River dolphin and the Irrawadday dolphin. These two freshwater dolphins are both living in the south-western region of Bangladesh, and a majority of the specimens can be found in the famous Sunderbans mangrove forest. The Ganges river dolphin prefers mangrove channels that receive plenty of freshwater while the Irrawadday dolphins live further downstream where the water in the mangrove channels are of higher salinity.

According to dolphin expert Elisabeth Fahrni Mansur, water extraction upstream in India and sea-level rises have cause the salinity of the river dolphin habitat to change. These changes in salinity might not only be a problem to the dolphins, over 30,000 Bangladesh fishermen relay on the aquatic life of the Sunderbans mangrove forest for their daily livelihood.

The Bangladesh Cetacean Diversity Project (BCDP) and the New York-based Wildlife Conservation Society (WCS) have now suggested that a protected area for dolphins consisting of three priority sites should be created in the Sunderbans mangrove forest. This will not affect the salinity of the water, but it will at least provide some refuge for the dolphins while the try to combat all the other problems.

Elisabeth Fahrni Mansur also wishes to work together with local fishermen to save the dolphins. Her idea is to get the fishermen to safely release dolphins from the nets and collect samples and basic information from dead specimens. In exchange, the fishermen will be provided with comparatively inexpensive GPS-systems and depth sounders which allows for safer navigation during bad weather.

You can read more here: http://news.bbc.co.uk/2/hi/south_asia/7192200.stm