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Saturday, October 8, 2011

Issues of the take of shark in Australian waters


The significant issues in regard to the take of shark in Australian waters include:

(a) a general lack of species identification and quantification of shark taken in some target and non- target shark fisheries

(b) lack of data collection and validation programs across some fisheries and jurisdictions

(c) the need for minimum data standards to ensure consistency and compatibility across fisheries and jurisdictions

(d) lack of scientifically defensible stock assessments for some targeted and important byproduct species

(e) the need to define the processes for identification of threatened species (eg CITES)

(f) need for assessment of the adequacy of management for all shark species (decision framework, objectives, reference points)

 (g) the lack of identification and use of appropriate management and conservation measures (State/Commonwealth/international)

(h) concerns for endemic sharks. (Eg. the majority of endemics are demersal and a large variety of shark species are taken by demersal trawling, but are currently mostly unquantified)

(i) where identified, the need to rehabilitate the chondrichthyan fauna on the continental slope (eg south-east)

 (j) Assessment and management of the overall impact on shark species which are taken in two or more fisheries (within jurisdictional issues, transboundary issues, international) 

(k) the need to develop shark bycatch reduction methods where appropriate (action – monitor use of BRD for chondrichthyans)

(l)            shark finning (volume of shark killed for finning, ethics, waste, sustainability) (section 2.5); (m)impact of shark imports to Australia on overseas shark populations (eg transboundary stocks, lack of reporting of trade statistics)

(n) ecosystem effects of shark management practices (trophic cascade, impact of increased shark populations, impact of prey removal)

(o) impacts and management of recreational and charter fishing (including lack of systematic reporting, target game fishing of sharks)

(p) reporting of shark catches from all sources

(q) management of fisheries with different productivity (commercial viability) – need to reconcile different productivity in multi-species fisheries

(r) impact of environmental degradation on sharks (uncertain effects of habitat alterations, nursery habitat degradation)

(s) uncertain effects of seismic survey associated with oil and mineral exploration

(t) cryptic mortality (eg net drop out, ghost fishing)
(u) handling practices of returned catch eg hemiplegia (cryptic mortality through partial paralysis due to the structure of the spine and the large cartilaginous sheets associated with the dorsal fin. Deformity of the spine and subsequent overgrowth of cartilage in the region may then slowly destroy the spinal chord)


Extracts and more info:

Sharks play a key role as the oceans top predators, maintaining the vitality of the ocean ecosystems, consequently, reducing the number of sharks may have significant and unpredictable impact on other parts of the ecosystem. The main species of sharks to inhabit the Great Barrier Reef possess home ranges, meaning they do not leave the area and are now being fished before they can reproduce (some taking up to 25 years to reach sexual maturity), having major impacts on the ecosystem. Others are highly migratory and have nursing areas susceptible to inshore fisheries actions. This fishery operates along Queensland’s east coast and extends through the Great Barrier Reef World Heritage Area. . There has been increased pressure on shark populations with more specialist shark fishers entering the fishery. Recorded commercial shark catch in this fishery plummeted from 1298t in 2003 to 603t in 2006. In this period there was only a slight decrease in fishing effort indicating that reduced catches of this extent resulted from a reduction in the availability of target shark species. 22 species of sharks, rays, skates and chimeras are found in the Great Barrier Reef, and inhabit a wide variety of habitats. Sharks due to their reproductive capacity are generally unable to cope with the levels of fishing most fishes are able to sustain, many shark fisheries around the world have collapsed.  Many include the same species that are caught as both target and bycatch in the ECIFF.
Recent work on the assessment of risk to the sustainability of sharks taken in the ECIFF identified the urgent need for information on biology, stock structure and optimal harvesting of these species. Management intervention for high risk species (such as scalloped hammerhead and great hammerhead sharks and white- spotted guitarfish) and the need for a further review of sustainability of sharks and rays is also required. However whilst research is underway, there is still a large amount of sharks being taken without knowing their biological data or the effects this is having on their species.
High and unselective mortality of sharks and rays from targeted fishing and incidental capture in the ECIFF poses a serious risk to this important functional group of predators and to the natural systems of the Marine Park. Risk assessments have shown that some species of sharks and rays in the ECIFF catch are at ‘high risk’ from fishing. By-catch in the ECIFF includes many species of sharks and rays, some of which are protected species (i.e. species in the Marine Park that are protected under the Great Barrier Reef Marine Park Regulations 1983 Regulation 29, and need special management). On an observer trip, All 20 species of sharks and rays observed in the ECIFF commercial catch were assessed, and of these 75 per cent were found to be particularly vulnerable to even small levels of fishing mortality. “In contrast, the shark catch in the East Coast Inshore Finfish Fishery (ECIFF) is highly non-selective, and very little is known about the biology of the constituent species,” warns JCU researchers. “More than 20 shark species are caught in this fishery, but we know virtually nothing about their natural abundances, birth rates, death rates, or movement patterns,” explains submission co-author Dr William Robbins. “This is the kind of information needed to determine what levels of fishing are sustainable, and to set regulations that minimize the risks to the most vulnerable species.” The disregard shown for shark species in the marine park, world heritage area and east coast of Australia is unsettling, we are ‘legally’ destroying a near perfect ecosystem.
Australia exports approximately 230 tonnes of shark fin annually, conservatively estimated to be equivalent of 10,000 adult sharks, all to support the delicacy ‘shark fin soup’ a huge Asian industry, one recognized to be unsustainable and a contribution to the destruction of our oceans worldwide. Australia’s contribution to the shark fin trade is a bad image not only the tourism community that spend billions of dollars annually on reef related industries, but also the less developed nations such as Palau that have created shark sanctuaries in their waters, instead of profiting form the exporting of fins. Australia with its vast ocean area should be a leader in ocean conservation, yet the underwater recreational, conservation and scientific community look down on us worldwide for removing sharks form inside the Great Barrier Reef World Heritage Area with the insufficient data to call it a sustainable practice. Currently there are also no regulations on imported sharks, illegal or unsustainable may be exported to Australia, therefore contributing directly to the demise of shark species around the globe. We have fallen behind in our conservation efforts, in a short time this will lead to a collapse of fishing industries and the tourism industry surrounding the reef, as well as every industry surrounding tourism.

For 400 million years it has been sharks at the top of the oceans chains, they are the creatures for which the oceans foundations have been set, they affect everything, and therefore their decimation has the potential to destroy everything. We are killing an estimated 100 MILLION sharks a year, a rate so fast the effects are not yet conclusive… in one scenario, the removal of tiger sharks resulted in a population explosion of sea birds. The increased bird numbers led to uncontrolled predation by seabirds on fishes to the extent that fish populations collapsed. 

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