Ups and downs in next year’s Baltic TACs

Published on May 29, 2009

For the first time in years, scientists have recommended increased catch quotas for both Baltic cod stocks in 2010.

Increase for both cod stocks

The advisory body, the International Council for the Exploration of the Sea (ICES), recommends a 15 per cent increase for the much larger eastern stock – the same as last year’s advice – and, “more surprisingly”, an 8.6 per cent increase for the western stock.

The European Union Fisheries ministers will have their final word on the allowed catches at their Council meeting in October.

An EU multiannual management plan for both cod stocks in the Baltic was adopted in 2007, which aims at restoring the fish stocks to sustainable levels. While the advice last year was generally based on the precautionary approach, it was now rather worked out within the frame of the management plan.

Western stock uncertainties

While the earlier threatened western stock is still classified by ICES as being “at risk of reduced reproductive capacity”, the scientists recommend a TAC increase of 8.6 per cent. Compared to last year’s advice – the EU Council chose to soften it slightly – it is an almost 28 per cent increase.

The reasons are twofold:

  • Earlier assessments of both the spawning stock biomass (SSB) and fishing mortality have been revised.
  • The advice is now based on the management plan. The plan stipulates that the fishing mortality shall be reduced by ten per cent from the preceding year, until the target – in this case 0.6 – is reached. With the assessed mortality now being revised, the mortality estimated for 2010, if the plan is to be followed, implies the increased TAC figure given.

There are some causes for uncertainty, however:

  • The considerable variations in assessments reflect uncertainty in themselves.
  • The future depends mainly on just one strong year class – that of 2008, while those of 2004–2007 were unusually weak. The class of 2008 is estimated with “high uncertainties”, according to ICES.
  • The advised TAC does not include discards, only landed catches, while the fishing mortality assessment did. Discard figures are very uncertain.
  • A pilot study in 2007 indicated that considerable amounts of cod were caught in the western Baltic by recreational fishermen. Such catches were not included in the assessment.
  • The management plan also specifies a 10 per cent reduction in fishing effort – total fishing days allowed at sea – per year. Compliance with this was only assumed when ICES estimated the TAC.

Eastern stock “overfished” no more

The eastern stock, more than seven times larger than the western stock, was, at its height in the early 1980s, one of the world’s largest.

It has diminished more than four times since then, partially due to overfishing and worsening environmental conditions in the Baltic Sea.

Its size is still on a historically low level, but with a fishing mortality well below the target set in the management plan (F = 0.3), ICES no longer classifies the stock as “overfished”, or “unsustainably harvested”.

Based on the target fishing mortality in the management plan, a higher 2010 TAC could be allowed, but the plan also limits TAC deviations from one year to another to 15 per cent. A 15 per cent increase was recommended last year, as well, which was agreed by the Council.

Since no reduction in fishing effort is required, while the stock is growing, ICES points out that the incentive for discarding and high-grading will increase. High-grading is the discarding of marketable fish to make room for fish of higher sales value. Discards are likely to rise above what was predicted when setting the TACs, ICES says. The scientists therefore recommend measures to improve the selectivity of fishing gear, for instance increased mesh size.

Some other causes for uncertainty:

  • Unreported – illegal – landings are included in the assessments at only 6 per cent, but those estimates, ICES admits, are “highly uncertain”.
  • Figures on discards are also uncertain, since ICES says sampling is insufficient.
  • Age determination is unusually difficult for Baltic cod. Landings with no age information were abundant in 2008, which probably leads to an underestimated fishing mortality.
  • In all, the problems with the catch and survey data and inconsistent age determinations make it difficult to precisely determine the strengths of the 2005 and 2006 year classes. Since the 2006 year class could make a major contribution to the catch in 2010 and the spawning stock in 2011, forecasts of catches and spawning stocks are especially sensitive to the estimated strength of that year class.

Decrease for central Herring fishery

The largest of the herring stocks in the Baltic Sea (areas 25–29 and 32, excluding the Riga Gulf) is now classified as “at risk” of being harvested unsustainably. The stock size is about 41 per cent of the long-time average. The fishing mortality has gone up, and exceeds what the precautionary approach stipulates. The last strong year class was the one on 2002.

Based on this, ICES recommends a TAC decrease of 28 per cent.

Since herring is caught together with sprat in these waters, and most of the herring TACs have been taken, ICES points out that there may have been an incentive to misreport herring as sprat, the extent of this unknown in that case.

In the Gulf of Riga, the ICES classification of herring harvesting is changed from “unsustainable” to “sustainable”. Based on the precautionary approach, the ICES advice allows a 4.3 per cent increase.

Herring from the Bothnian Sea (Subdivision 30) is for most Swedes associated with the local tradition of preparing the foul-smelling fermented herring (“surströmming”) for the fall season, starting on the third Thursday in August. That aromatic cloud may spread to larger parts of the nation next year, with a recommended TAC increase of 32.5 per cent.

The spawning stock tripled in the late 1980s, and has remained on a steady level ever since, and the fishing mortality has stayed under the precautionary approach level for more than 30 years.

One problem looms in the future for this stock, however: its dioxin concentration has remained above EU limits for some time, even though Sweden and Finland has a dispensation that runs out after 2011. That concentration has shown no signs of going down – on the contrary, the current excellent state of the stock may make the problem worse as older specimen are likely to have accumulated larger dioxin concentrations, and their share in the stock goes up when the mortality is low.

Cods and fishermen compete for sprat

The sprat stock, the largest fish stock overall in the Baltic, is highly steered by the abundance of cod, since sprat is a main food source for the latter. With the cod stock recovering, the fishing mortality is now higher than the precautionary approach prescribes, and ICES classifies the stock as at risk of unsustainable harvesting. For 2010, ICES recommends a 23 per cent decrease in the TAC for Baltic sprat (it is managed as a single stock).

The future development of the Baltic sprat is very much dependent on this year’s and next year’s year classes, but also on the development of the Eastern Baltic cod stock. A much-wanted recovery for the cod stock may mean that the exploitation of the sprat stock will have to be reduced.

Salmon recommendation in line with real catches

Baltic salmon management is divided into two areas – the main basin and the Bothnian Gulf (Subdivisions 22-31) and the Gulf of Finland (32). For the assessments, the former area (22-31) is divided into five units.

In the two northernmost units, the production of smolt (young salmon) has increased almost tenfold since the Salmon Action Plan was adopted in 1997.

Within the last five years the total wild smolt production of all the assessment units combined has increased by 50–60 per cent. Compared to the natural smolt production capacity, however, it is still low in many rivers, and ICES advises reduced catches by 57 per cent. Since only a small part of the TACs have been utilized in later years – 35 per cent in 2008 – this is in practice an adjustment to the actual effort

ICES adds that salmon management should be focused on the individual stocks in the rivers – where some are especially weak and some are stronger – since fisheries on a mix of natural/reared stocks along the coasts or in open sea are harder to deal with.

As for the salmon in the Gulf of Finland (Area 32), ICES says that the new data available for this stock are too sparse to revise the advice from last year. That was a recommended TAC of 15,000 specimens – but only reared fish. ICES says that no catches at all of wild salmon should be allowed in the Gulf and that the poaching taking place in some of the rivers “must be stopped”.