Investigations on the shrimp and prawn fisheries in the Western Baltic
- Palaemon adspersus (Rtk.) and Crangon crangon (L.) occur at the Wismar Bight and they are also present in the Western Baltic.
- Palaemon adspersus may be caught in the Wismar Bight from June to October near the shore in a depth of 0.2-0.7 m with the push net and from April to November in a depth of 3-4 m with a dredge (like a beam trawl).
- Crangon crangon may be caught close to the shore from April to December in a greater numbers with the push net. Between January and March there are only few specimens. The dredge catches of Crangon crangon have the same results as of Palaemon adspersus.
- Through measurements of 7 461 brown shrimps (Crangon crangon) and of 1 474 baltic prawns (Palaemon adspersus) a mean lengths of 38.5 mm (max. 76 mm) of Crangon and of 48.9 mm (max. 75 mm) of Palaemon were determined.
- The majority of the brown shrimps are caught at sandy bottom; the baltic prawn is best caught at or between the plants.
- The majority of one-year old Crangon crangon, and one- to two year old Palaemon adspersus specimens may be caught with push net, dredge and prawn pot.
- The separation of sexes is possible using the length of the endopodite of the first pleopod above a body length of 35 mm (only Crangon crangon). All the other specimens separated with the formation of the Appendix masculina on the endopodites of the second pleopod (Crangon and Palaemon).
- The sex ratio of females to males is, on the year's average of 158 baltic prawns, about 2.3 : 1.
- At Crangon crangon the sex ratio of females to males is, on the year's average of 772 specimens, about 4.4 : 1.
- Egg-bearing Palaemon females may be caught between June and August. The smallest female with eggs was 36 mm.
- The spawning by Crangon crangon is between April and November. The smallest female with eggs, caught in the Wismar Bight, was 29 mm.
- There is a commercial fishery on the baltic prawn in the Western Baltic (Wismar Bight, Germany and Lolland/Falster, Danmark) as a regional speciality.
- The mean catches of the year of the baltic prawn reach 2-4 t. It is a seasonal fishery from May to August.
- In Danmark is the prawn fishery more important than in Germany. The mean catches per year reach about 70 t.
- The large part of the catches was taken in Germany and in Danmark with a prawn pot.
- An increase of the prawn fishery in the Western Baltic is unlikely, as the population of the prawns fluctuates to much.
Christian Lückstädt. Untersuchungen zur Garnelenfischerei in der westlichen Ostsee (Investigations on the shrimp and prawn fisheries in the Western Baltic). M.Sc. Thesis, Humboldt University, Berlin 1996.