Crayfish Review 2007

The Crayfish Review 2007 updates the previous review, giving the latest crayfish production statistics and information on current issues involving the developing crayfish industry. The review is produced by the Crayfish Research Program of the Finnish Game and Fisheries Research Institute.

In 2006, ten professional crayfishermen from around Finland (five for noble and five for signal crayfish) started to report their fishing effort and catches. Their intensive catching season lasted from 21 July until late September. On average, 7 460 noble and 10 597 signal crayfish were caught per fisherman. The fishing effort was 5 994 trap nights for the noble, and 21 600 trap nights for the signal crayfish. Due to the differences in catching methods, the noble crayfish CPUE was higher than that of the signal crayfish (6.22 and 2.45 respectively).

According to the fishery statistics in Finland, recreational fishermen caught 5.2 million signal and 1.6 million noble crayfish in 2006. The total catch has more than doubled since 2004. Professional fishermen caught about 95 000 crayfish. Thus, the total catch in 2006 was about 6.9 million noble and signal crayfish. About 71 000 young-of-the-year crayfish were produced in aquaculture, of which 55 000 were signal and 16 000 noble crayfish. The total production of crayfish farmed for food was estimated at about 36 000 individuals in 2006, of which 92% were signal crayfish. The production decreased compared with 2005.

In 2005 and 2006, about 185 000 noble and signal crayfish were stocked into lakes and rivers. The stocking numbers and species relations remained at the levels of the past 5-10 years.

Crayfish stocking results have been monitored in a large number of waters. In the noble crayfish waters where the follow-up period after the stockings allowed for the development of the population, about a third of the stockings were successful, a third failed completely, and a third produced sparse, slowly-growing populations. Correspondingly, in the signal crayfish waters where the stocking results could be evaluated, 82% were successful, 4% failed completely, and 14% produced a sparse population.

Crayfish plague was diagnosed in 11 crayfish waters in 2007. The signal crayfish of Lake Etelä-Saimaa were also badly infected. Of the plague cases detected in crayfish, six were of the signal and five of the noble crayfish type.

The annual consumption of whole fresh and frozen fresh-water crayfish in Finland is at present around 10 million individuals of 35–40 g. About 3 million signal and noble crayfish were Finnish, the rest were imported, mostly from China and Spain