Value of nursery habitats
Most of the economic value of the nursery habitats arises from the avoided costs of stock replenishment. Stock replenishment is carried out in Finland for some fish and game bird species.
Smolts of salmon (Salmo salar) are released in rivers Kemijoki, Iijoki and Oulujoki in northern Finland and Kokemäenjoki and Kymijoki in southern Finland. At present, salmon stockings are not cost-effective. Most of the smolts die before they're caught by professional fishers. The total economic loss is 3 €/kg or more. If recreational fishers are included in profitability estimations, the profit turns in most cases slightly positive.
Sea trout (Salmo trutta) and marine whitefish (Coregonus lavaretus) stockings are also carried out in some rivers that run into the Baltic Sea. Also their cost-effectiveness has been decreasing as the survival rate of juveniles is low. Research is ongoing in order to find out reasons for recent development. Some affecting factors may be the environmental change in the Baltic Sea, and changes in fishing and the quality of juveniles.
Some game bird stockings are carried out in Finland. These species are pheasant (Phasianus colchicus), grey partridge (Perdix perdix) and Canadian goose (Branta canadensis).
Nursery habitats maintain many economically important populations but, at the same time, they are important breeding grounds for a wide pool of species. They maintain species diversity directly and indirectly through complex food web and interrelations of species. It is considered intrinsic value that species continue to reproduce in their natural nursery habitats.
Social value of nursery habitats springs mainly from the recreational aspect of hunting and fishing. Fish and game species' successful reproduction and the availability of suitable and unspoiled breeding habitats ensure populations that can endure the fishing and hunting pressure. Social value of nursery habitats are also the viable fish populations for professional fishing and thus the employment in fishery.
Health value of nursery habitats arises from the health risks that are connected to the loss of nursery habitats. Species that grow and live in contaminated environment are usually also contaminated themselves, for example by environmental toxins. These toxins can transfer into humans through nourishment. There are already some fish species that's use has been restricted such as the populations of the Baltic herring, salmon and trout in the Baltic Sea.
Salminen, M. 2011. Istutustutkimusohjelman (2006-2012) väliraportti. RKTL:n työraportteja 1/2011. Game and Fisheries Research Institute. 71 p. [In Finnish]
Jyräsalo, T. & Ollikainen, M. 2005. Suomenlahden lohi-istutusten kannattavuus. Kala- ja riistaraportteja nro 372. Game and Fisheries Research Institute. 53 p. [In Finnish]
- Updated (13.11.2018)