Posted by: Hendra Siry | 25 May, 2009

Managing Whale `Hot Spots’ While Protecting Fisheries

Article by Benjamin Kahn and Johannes Subijanto

At the World Ocean Conference (WOC) in Manado, the Indonesian government has made a number of significant commitments to protect our unique marine biodiversity and secure sustainable fisheries. The declaration of the 3.5-million-hectare Savu Sea Marine National Park on May 13 at the WOC by Indonesian Marine Affairs and Fisheries Minister Freddy Numberi recognizes the unique nature of this area as a whale sanctuary and provides a mechanism for the sustainable management of fisheries for the benefit of local people.

The Savu Sea becomes the largest marine protected area (MPA) in the coral triangle region and contributes significantly to Indonesia’s commitment to create 10 million hectares of MPAs by 2010. The Savu Sea is encircled by the island chains of East Nusa Tenggara and Timor Leste, and forms the juncture between two of the world’s great oceans – the Pacific and Indian oceans. The dramatic volcanic landscapeof this region is matched by its underwater seascape. Exceptionally strong currents are generated by the passage of the Indonesian through flow – a unique and massive current that flows from the Pacific to the Indian Ocean – through the narrow channels between the islands. Shallow coral reefs drop steeply to depths of down to 4,000 meters, and deep-sea habitat features like seamounts and underwater canyons occur within kilometers of the coast, creating the so called “deep-sea yet near-shore” habitats.

This combination of strong currents and steep underwater cliffs creates seasonal but predictable “upwelling zones” where cold, nutrient-rich water reaches the surface. Here, rapid production of plankton fuels a food chain that starts with sardines and goes all the way to the top. The Savu Sea’s upwelling zones are used by large marine life such as whale sharks, dugongs and manta rays, and endangered sea turtles also ride these currents and use remote islands as important nesting sites.

However, the most impressive inhabitants are two of the world’s species of great whales – the deep-diving sperm whale and the mysterious blue whale. Both use these upwelling zones as critically important feeding grounds along their migration routes.

Sperm whales can reach 18 meters in length, while the blue whale can grow to up to 31 meters – the largest creature ever to roam the Earth. Blue whales are an endangered species and thus fall under various international treaties to which Indonesia is a signatory and therefore committed to their protection.

The incredible productivity of the Savu Sea also supports pelagic fisheries such as a sizeable “pole and line” pelagic fishery for tuna and billfish. Pelagic fisheries such as these sustain the livelihoods of around 4.5 million people living in this region. The proximity of these upwelling areas to the coast makes these fish stocks accessible to local communities.

Closer to shore, these productive cold-water upwellings could be a key factor in conferring resilience to coastal reef systems that face the growing threat of rising sea surface temperatures linked to climate change. Importantly, the deep yet narrow straits of the Savu Sea serve as migratory corridors for the great whales and other large marine life traversing these waters, bringing them in close contact with the coast and local communities.

Increasingly, the sustainability of fisheries and the survival of this unique gathering of large marine life are coming under threat fromindustrial deep-sea fishing, waste dumping from mines and environmentally unfriendly fishing gear such as gill nets, long lines and purse seines. Because blue whales spend a large part of their time at or near the surface at night, they are likely to become entangled in offshore gill nets. Any increase in local gill net use as part of fisheries development programs for local communities may increase the threat to these and other large marine life of the Savu Sea.

In addition, the Savu Sea is a major international shipping channel for oil and gas tankers and bulk carriers traveling from the Western Pacific to Australia and Asia. These sea lanes overlap with several of the primary migratory bottlenecks for large marine mammals and may pose a risk of ship strikes. Pollution caused by disposal of sediment and toxin-loaded tailings from coastal mines near the shore also poses a significant threat to both the marine life and local fish stocks.

Thus the development of the Savu Sea Marine National Park together with other management and conservation initiatives in the Lesser Sunda-Timor Leste region is the first time in Indonesia that an integrated approach has been taken to both deep-sea and shallow-water habitat protection and species management. If properly protected, the Savu Sea could become a refuge for marine life and ensure productive fisheries amid global climate change. In order to achieve such an outcome, a long-term management plan with a strong emphasis on large marine life and sustainable fisheries is needed.

By discouraging damaging fishing gear such as gillnets and long lines and encouraging gear used locally such as poles and lines (which feature minimal by-catch and no net entanglement risks), overfishing and by-catch of marine life will be reduced. Existing regulations for shipping and prevention of waste dumping at sea also need to be implemented. Such strategies will ensure the Savu Sea is managed for the benefit of local communities and ensure the survival of some of the world’s most endangered and majestic marine life – the great whales.

Benjamin Kahn is director of APEX Environmental and Johannes Subijanto is the Nature Conservancy’s (TNC) Sunda-Banda & Sulu-Sulawesi Seascapes portfolio manager.

Source: The Jakarta Post – May 14, 2009.


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