Wales is taking steps to address a decline in skate catches in local commercial fisheries, with annual landings having dropped from 18,000 to 3,000 tons over the past 40 years. Not only are skates in trouble off Wales, species such as the barndoor and thorny skate are being severely depleted in US Atlantic waters.A large female Greenland shark measuring 730 cm TL was caught by a French fishing boat at a depth of 1100 m. It was suggested that this species and the related Pacific sleeper shark may reach sizes larger than the great white shark.The US population of the smalltooth sawfish has declined by over 95%.Trade in shark fins is believed to represent one of the most serious threats to shark populations worldwide. We were told subsequently at the Spanish meeting that the fins of as many as 40 million sharks annually are estimated to enter the fin trade.Deep water sharks are being taken as bycatch by bottom trawlers to the west of the British Isles and there are concerns that these very vulnerable animals may be being severely impacted.Satellite tracking of basking sharks indicates that these animals do not lie on the seabed and hibernate in winter, as was previously suggested. Also, they are able to locate with amazing precision small, isolated, short-lived plankton blooms. It is not known how they do this.Juvenile blacktip sharks using a bay on the west Florida coast as a nursery ground left the bay and headed out to sea just prior to the arrival of a major tropical storm. It is thought that they were able to anticipate the arrival of the storm by detecting a drop in atmospheric pressure.

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Elasmobranchs generally have low intrinsic rates of population increase. Certain small, relatively fast-growing shark species can be sustainably harvested at commercially viable rates, however.

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The Atlantic sharpnose shark, a close relative of the milkshark found off South Africa’s east coast, appears to be maturing at a smaller size and growing faster now than 15 years ago. It is possible that this is a density-dependent response to harvesting, a phenomenon seldom described in sharks.

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Survival and mortality estimates of juvenile blacktip sharks using a west Florida bay as a nursery were estimated directly using sonic tags and acoustic listening stations.

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Information on stock structure is often lacking. A stock that appears discrete may in fact consist of a metapopulation of stock components. There is accumulating evidence of phenomena such as philopatry, including natal homing, and of localised stock depletion. Spatial features need to be incorporated into models. The use of pop-up archival satellite tags to resolve stock structure, although expensive, is of growing importance. There was some disagreement on the usefulness of genetic markers for identifying management units.

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An example of natal homing was the tendency for tagged juvenile blacktip sharks on the Florida coast to return to the particular bay where they were born.

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Two juvenile great white sharks with satellite tags followed very similar routes along the Australian east coast. Were they following specific "highways"?

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Although it is possible to use genetic techniques to identify to species level shark parts (e.g. headed and gutted carcasses, fins) sampled from fishing boats and fish markets, it is a slow and expensive process and thus not very useful for law enforcement. Research is continuing into developing practical methods for testing multiple samples.

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The most intensively researched and managed shark fishery is Australia’s "Southern Shark Fishery" that targets primarily gummy sharkMustelus antarcticus and school shark Galeorhinus galeus(also known as the soupfin shark). These two species have very different life history characteristics with the result that the gummy shark is able to sustain moderate fishing pressure but the school shark is not. It was emphasized that all school shark fisheries (such as that off South Africa’s Western Cape) require very careful management.

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Models appropriate for elasmobranch fisheries have been developed. For example, a variant of the Integrated Analysis Method is used to assess gummy shark populations (Pribac et al.). The model is age- and sex-structured and incorporates gear selectivity and the peculiarities of the pupping process. Catch, catch-rate, length-frequency, age-composition and tagging data are used within a maximum-likelihood estimation framework.Ideally, new shark fisheries should not be allowed to develop until an assessment has been undertaken. This

A point to consider with regard to South Africa’s relatively undeveloped shark fisheries?

One paper suggested that the best method for sustainable harvesting of sharks is to catch juveniles only. Individuals that reach reproductive age are no longer subject to fishing pressure. This concept is called a "gauntlet fishery" – once the sharks have run the gauntlet as juveniles, they are safe from capture. (It has been suggested that this approach is useful only for species with juveniles large enough to have commercial value.) The author expressed concern about long-term harvesting of adults, even at low exploitation rates.Pelagic sharks are taken as bycatch in tuna longline fisheries in many parts of the world. In New Zealand’s EEZ, for example, the estimated bycatch in 1997-98 was 45,000 blue sharks (1,400 tons), 4,000 porbeagles (150 tons) and 3,000 shortfin makos (200 tons). Initial evaluation is that these catches are probably sustainable, although it is likely that the same stocks are being exploited elsewhere in the Pacific as well. Some blue shark stocks are being depleted, such as in part of the north-west Atlantic.It was suggested that different species need to be managed with different objectives, i.e. some for sustainable utilization and some to maintain biodiversity. The point was made that, for biodiversity maintenance, strictly one should manage fisheries with regard to the most vulnerable bycatch species rather than the target species, which tend to be more productive.Another suggestion was that MPAs are needed at depths below 400 m to protect shelf-slope species whose life history characteristics and restricted habitat make them especially vulnerable.Australia plans to conduct a risk assessment of every shark and ray species in its waters with regard to vulnerability to fisheries impact. Parameters such as longevity and fecundity will be used as a rough guide to productivity.

i. Elasmobranchs as a group are generally vulnerable to over-exploitation.

ii. There is particular concern about the low-productivity species taken as bycatch in various fisheries.

iii. Improved reporting mechanisms and enforcement are needed.

iv. Increased public awareness has led to increased attention being focussed on these animals.

i. Establish appropriate management measures for the thorny skate and investigate the status of other species in NAFO waters.

ii. Increase investment in research and management.

iii. The precautionary approach (to managing shark fisheries) is needed in general.

iv. All nations should produce national plans of action for their shark resources, in accordance with the call from the UN’s Food and Agriculture Organisation (FAO).

v. NAFO countries should assist developing nations to develop management frameworks for their elasmobranch resources.