3.C.2.1 Aquaculture

The collapse of the fishery has created a crisis in employment in the fisheries sector, and reduced food security in protein resources. In consequence of reduced availability of fish, market prices for fish are already rising, and there seems no evident price ceiling in sight on world markets for certain fishery products. This is setting the scene for development of the aquaculture sector which is seen as one of the more promising areas for economic development when fish prices reach a level justifying the appropriate investments.

Restoration of economic productivity/employment in fishery sector will be aided by a well developed aquaculture system. Aquaculture in the Black Sea is still at an early stage, although there has been a long experience in sturgeon culture, (especially in the Azov Sea), and more recently, the cultivation of shellfish, notably mussels and oysters. More recently, cage cultivation of Atlantic salmon has begun in Turkish waters.

Environmental problems

There is already indication that cage culture of salmonids, sea basses and sea breams produces local eutrophication, so that proper regulations governing density of stocking in relation to local conditions need to be applied. The possibility could be investigated on a pilot scale within marine lagoons, of using aquaculture techniques to cultivate mussel and off bottom red algal culture to decrease turbidity, absorb excess nutrients and increase oxygen. The products of this should be tested prior to use for human food, but could be considered as industrial or agricultural use, if the methodology proves effective.

Other ecological risks and considerations

The difficulties of developing an environmentally responsible aquaculture sector have increased following the Biodiversity Convention. The importation of new species and specialized strains of existing species is in contravention of the Convention, but is common practice within the commercial aquaculture sector where broodstock or juveniles can be purchased commercially through a worldwide commercial network. The possibility of importing exotic species and disease vectors in brood stock requires regulations based on for example the ICES Code of Conduct for importation of brood stock. Importing of exotic genetic material from outside the region should be reviewed first by governments of the region, and if agreed, strict quarantining is essential. Consideration could be given in some cases however to the feasibility of production of sterile hybrids which would not affect biodiversity.

Importation of exotic species capable of reproducing in the wild is restricted under the Biodiversity Convention. This poses practical problems, given that in the view of many specialists, the ecosystem has changed irreversibly, both due to economic development in the watershed, and the accidental importation of new species which have changed the original marine fauna and food web of the basin. It is of interest in this connection, to consider why so many new species have been entering the Black Sea over the last decade. This is probably a consequence of the change in the ecosystem of the Black Sea from oligotrophic to eutrophic conditions, which has reduced old ecological niches and created new ones which cannot be filled by native species. It also offers opportunities for (e.g.) detritus feeding species (haarder and native blue mussel), and favours species capable of surviving hypoxic conditions (such as Mya).

What species should be used for aquaculture?

As a result of concerns with importing of exotics, the use of native species for culture-based fisheries was promoted globally in the 1970’s and 70’s. More recently, there has been growing concern with genetic contamination of native stocks due to culture of single strains of the commercial broodstock of the species, where artificial selection (e.g.) for good growth under cage culture conditions has begun, or a broodstock with low genetic diversity is used. Mixing of escaped aquaculture stock with native stocks is feared to result in genetic ‘contamination’ of native stocks, and evidence for this is often cited from the Baltic Sea, and elsewhere. Similar concerns have been expressed with respect to the substitution of natural runs of sturgeon by hatchery operations.

Sea ranching

The real probability exists that feeding conditions in the Black Sea may be close to optimal for some species (especially those preying on jellyfish and ctenophores) but that their natural larval life in the plankton is inhibited by the same jelly predators,. This has raised the possibility of applying sea ranching (breeding ashore and release into the sea for subsequent capture in the wild). Various candidate species have been suggested for evaluation, both native and exotic. In theory, the second category could in part satisfy the spirit of the Biodiversity Convention if sterile hybrids of exotics were released.

Major problems of a practical and legal nature are also being faced in practice with sea ranching of sturgeon, where the investment in hatchery operation is not shared by all those harvesting the stock in the wild, and this is a major disincentive for private sector investment in this potential new industry.

Operational targets

Governmental decisions on rules governing sea ranching need to be developed and coordinated; including questions of preferential access to species produced in this way. Draft laws have been prepared in some countries governing aquaculture practices and these need coordinating; especially as regards requirements for importation and quarantining of aquaculture materials. The requirements of the Odessa Declaration for evaluation of the impacts of intensive aquaculture should be borne in mind.

See also

3.C.2.1 Aquaculture
3.C.2.1 Trout shore-based aquaculture
2.C.2.1 Developing aquaculture and sustainable tourism (aquaculture)