Fishing News International March 2004

Seven of the world's leaders in fisheries science spent five days in Cape Town last month critically reviewing the science behind the management of the South African and Namibian hake fisheries.

Up to 400 000 tons of hake are landed in South Africa and Namibia every year to provide thousands of jobs and important foreign exchange earnings. However, both countries are currently experiencing poor hake catches.

The week-long scientific workshop was sponsored by the regional scientific programme, BENEFIT, the Benguela Current Large Marine Ecosystem Programme and South Africa's National Research Foundation.

It was attended by scientists, managers, students, representatives of the South African and Namibian hake fishing industries and even a member of the South African parliament.

Invited scientists were Drs James Ianelli, Joseph Powers and Andre Punt from the USA, Drs Robin Cook and John Pope from the UK, Dr Tore Strømme from Norway and Dr Tony Smith from Australia. Tony Smith chaired the meeting organised by South African assessment expert, Professor Doug Butterworth.

The workshop reviewed every step of the stock assessment process - from data inputs through to models and management procedures - to make recommendations for future research.
Many fishing industry representatives attending the workshop were concerned about the region's downturn in hake stocks.

Namibia's hake fishing industry has been hard hit by poor catch rates and a high proportion of juvenile fish in landings. In South Africa, stock assessments have suggested that the total allowable catch (TAC) is too high.

Although two quota cuts of 3 000 tons each have been implemented in South Africa, scientists say that a further 3 000 ton cut will have to be made in 2005. Even then, catches may be too big in the short term, but will probably stabilise in the medium- to long-term.

Weaker than normal cohorts entering the fishery in the late 1990s are being blamed for the problem.

South Africa's situation is complicated as scientists believe that there is too much fishing pressure on the shallow water hake, Merluccius capensis. This species is targeted by small boat handline fishermen, longliners, 30m inshore trawlers and 45 to 70m deep-sea trawlers. In contrast, the deep-sea hake, Merluccius paradoxus, is landed primarily by deep-sea trawlers.

The relationship between the line and trawl fisheries was one of the most important themes to emerge from the workshop, with the need for improved research into the hake line fisheries being one of the scientific panel's key recommendations.

According to Tim Reddell of Quayside Fish Supplies, this was one of the most positive results of the workshop from the fishing industry's perspective.

He says that the relationship between longlining and trawling has not been properly investigated and he is increasingly concerned about the growing conflict between longliners and trawlers on the south coast.

"When longlining was introduced, it was assumed that it would extend the trawling grounds because the longliners would fish on rough ground. But this hasn't happened," he says.

Instead, longliners have moved off the rough grounds and onto the trawling grounds, causing conflict between fishermen and potentially threatening the stability of the south coast hake stocks.

"There are too many boats in a small area. For longlining and trawling to be conducted in the same area is illogical," he maintains.

Longliners catch predominantly sexually mature, female hake, while trawlers generally catch every size and sex.

"From a management perspective, the workshop raised a lot of questions around the inter-relationship between the longline and trawl industries, but now we need to see some action," says Tim Reddell.

Another major theme to emerge from the workshop was the question of how many hake stocks are fished off South Africa and Namibia.

Scientists have always believed that there are separate stocks of shallow water hake on the west and south coasts and that the Namibian and South African stocks of deep-water hake are separated by the Orange River.

However, workshop participants agreed that it is more likely that there is a single stock of shallow-water hake and a single deep-water hake stock off South Africa. Also, there are indications that there may be greater overlaps in the deep-water hake stocks off Namibia and South Africa than originally thought.

If this is found to be true, then it there are important implications for future TAC sharing arrangements. This issue is already being tackled by the regional Benguela Current Large Marine Ecosystem (BCLME) Programme.

One of its most important objectives is to set up a regional authority to advise on the transboundary management of shared stocks.

The workshop recommended that scientists continue to work with population geneticists in an effort to determine the exact relationship between hake caught on either side of the Orange River.