Oversimplification of complex harvest modeling issues outlined in Welch et al. (2014)

Animal Biotelemetry

T Mark Willette²  Pat Shields²  Eric C Volk¹ 

[1] Alaska Department of Fish and Game, 333 Raspberry Rd, Anchorage 99518, Alaska, USA

[2] Alaska Department of Fish and Game, 43961 Kalifornsky Beach Rd. Suite B, Soldotna 99669, Alaska, USA

关键词: Fishery management;    Harvest modeling;    Gillnet fishery;    Swimming depth;    Migratory behavior;    Acoustic telemetry;    Oncorhynchus nerka;    Sockeye salmon;    Oncorhynchus tshawytscha;    Chinook salmon;   

Others  :  1147468
DOI  :  10.1186/s40317-015-0027-x

 received in 2015-02-03, accepted in 2015-03-11,  发布年份 2015

【 摘 要 】

In their paper, ‘Migration behavior of maturing sockeye (Oncorhynchus nerka) and Chinook salmon (O. tshawytscha) in Cook Inlet, Alaska, and implications for management,’ Welch et al. (Anim. Biotelem. 2:18, 2014) report data on migratory behavior and relative swimming depths of Chinook and sockeye salmon near the Eastside Setnet (ESSN) fishery, Cook Inlet, Alaska, using acoustically tagged fish and an anchored array of acoustic receivers. Using this information, they provide a model to estimate changes in Chinook and sockeye salmon harvests associated with potential regulatory changes affecting surface gillnet depths in this fishery. We are concerned that the modeling exercise paints an unrealistic picture of how simply changing gillnet dimensions would translate into a viable management approach to preserve or increase sockeye salmon harvests while minimizing catch of Chinook salmon. Much of this fishery occurs in very shallow water, and Cook Inlet tides range about 10 m with tidal current speeds reaching about 9 km hr⁻¹. Model assumptions that gillnets in this dynamic environment were hanging vertically and that gillnets did not reach the bottom are not valid. Gillnets in this fishery billow in strong currents causing the lead lines at the bottom of the nets to rise in the water column, and an unknown but high fraction of all gillnets reach the bottom for some portion of each tide cycle. We believe further information and a more sophisticated analysis is needed to realistically model changes in Chinook and sockeye salmon harvests in relation to gillnet depths, and we are concerned about unintended consequences that may arise from unrealistic solutions based on limited data proposed in the regulatory arena.

【 授权许可】

   
2015 Willette et al.; licensee BioMed Central.

【 参考文献 】

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