Friday, June 25, 2010

At the Forefront!

From The status of chondrichthyan conservation in the Indo-Australasian region.


Sharks, batoids (rays) and chimaeras (Class Chondrichthyes) are considered to be particularly vulnerable to over-exploitation as a result of their K-selected life-history strategies, which is generally characterized by low fecundity, slow growth, late age at maturity and long life spans (Stevens et al., 2000).
Population declines and localized extinctions have been documented for a number of chondrichthyan fishes (Dulvy et al., 2000; Simpfendorfer, 2000; Stevens et al., 2000; Graham et al., 2001; Frisk et al., 2002).

Many chondrichthyans play an important role as apex predators at the top of the food chain and their removal can have serious top-down effects on the ecosystem, i.e. through trophic cascades (Myers et al., 2007; Baum & Worm, 2009).
Thus, the conservation of both the biodiversity and the populations of chondrichthyans is critically important to maintain healthy marine ecosystems.
The main threats affecting chondrichthyans worldwide are fishing (both indirect and direct) and habitat degradation. Most of the available information, however, relates to the effects of fishing.

Understanding the threatening processes affecting a species is paramount in understanding its conservation status and for directing effective management.
International concern for the status of shark (all chondrichthyans) populations has increased since the 1990s and led to the development of the International Plan of Action for the Conservation and Management of Sharks (IPOA-Sharks) (FAO, 2000). Although implementation of the plan is voluntary and not adopted in many areas, it still reflects the growing concern on an international level for declining stocks of sharks.
The main premise of the IPOA-Sharks is that the harvest of sharks should be biologically sustainable, economically rational, using all parts of the animals killed and managed to maintain biodiversity conservation and healthy ecosystem functioning
(FAO, 2000).

Since the early 2000s, the IUCN Species Survival Commission’s Shark Specialist Group (SSG) has been committed to assessing the conservation status of all chondrichthyan species for inclusion on the IUCN Red List of Threatened Species (the Red List) (IUCN, 2009).
The Red List is widely recognized as the most comprehensive source of information on the conservation status of the world’s plant and animal species (IUCN, 2001). The Red List has been paramount in highlighting the global status of sharks.

The movement towards increased conservation of chondrichthyan species worldwide has yielded many positive results to date.
For example, in 1988, the Philippines issued a Fisheries Administrative Order prohibiting the capture of manta rays (Mobulidae) and whale sharks Rhincodon typus Smith in its waters (White et al., 2006a).
In more recent years, Taiwan has ceased its R. typus fishery due to increasing international concern over the status of populations of this species.

In 2003, Fiji established the Shark Reef Marine Reserve within which fishing is prohibited and local villagers receive a levy from dive operations capitalizing on the protected area (Brunnschweiler & Earle, 2006)

Conservation efforts, however, need to increase and improve in order to better protect chondrichthyan fishes at both global and regional scales.

One of the many problems facing conservation of marine species, particularly sharks and rays, is the trade-off between knowledge acquisition and conservation action. This trade-off becomes particularly problematic in tropical developing nations, particularly south-east Asian countries, where some of the world’s greatest species richness occurs (Briggs, 2003, 2005), coupled with the greatest need for protein by the substantial populations. Further exacerbating this is the increasing export of marine products from these regions.

These countries, however, have little capability to undertake the scientific research required to assess the sustainability of current fishing practices, and therefore, developing adequate conservation actions is extremely difficult (Ban et al., 2009).
Thus, although most of the positive conservation efforts in marine environments are occurring in developed nations, the paucity of such efforts in developing nations is of grave concern.


BeachNomad said...

Great acknowledgment. Always good to see that your efforts are recognized. Especially the great work you guys are doing out at SRMR.

DaShark said...

Thx buddy!

Howzit down there?
Must be totally shocking to come back to that nightmare!

Best of luck!