Impacts of mesh-size regulation of gillnets on the pikeperch fisheries in the Archipelago Sea, Finland

• Published in: Fisheries research Vol. 77; no. 2; pp. 192 - 199
• Main Authors: Heikinheimo, Outi, Setälä, Jari, Saarni, Kaija, Raitaniemi, Jari
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.02.2006; Elsevier
• Subjects: Agnatha. Pisces; Animal, plant and microbial ecology; Applied ecology; Biological and medical sciences; Exploitation and management of natural biological resources (hunting, fishing and exploited populations survey, etc.); Fisheries management; Fundamental and applied biological sciences. Psychology; Marine; Sander lucioperca; Socio-economic impacts; Vertebrates: general zoology, morphology, phylogeny, systematics, cytogenetics, geographical distribution; Europe; Finland; ANE, Finland; Sander lucioperca; Socio-economic impacts; Fisheries management; Vertebrata; Fishery; Pisces; Selectivity; Economic impact; Teleostei; Socioeconomics; Osteichthyes; Fishing gear
• ISSN: 0165-7836; 1872-6763
• DOI: 10.1016/j.fishres.2005.11.005

In the Archipelago Sea, one of the most valuable species in the professional and recreational fisheries is the pikeperch ( Sander lucioperca), mainly caught with gillnets. Currently, the minimum mesh size (bar length) for pikeperch gillnet fishing in the Archipelago Sea is 43–45 mm. Enlarging the mesh size has been suggested to ensure the biological sustainability of pikeperch fishing. The impacts of enlarging the minimum allowable mesh size to 50 mm were analysed using a bio-economic simulation model and data based on pikeperch samples from professional catches from 1978 to 1997, and catch statistics. The effect of uncertainty in the variable values was examined by specifying probability distribution functions for the main variables and using Monte Carlo simulation. According to the results, the yield would be reduced by 50% in the first year, but after some years it would stabilise at about 20% higher level than before the shift. The biomass of the spawning stock would be doubled as a result of the larger mesh size, which would reduce the risk of low recruitment and benefit the fisheries in the long term. However, the short-term impacts on the profitability of commercial fishing would be negative, because it would take 3 years before the expected present value of the catch exceeded the value prior to the change in mesh size, and 8 years before the expected net present value of the catch would be positive. The challenge for fisheries management is to find a solution that would be both biologically and economically reasonable.