Investigating factors that influence the catch rates of northern stone crab (Lithodes maja)

• Main Author: Mbakwe, Anulika Blessing
• Format: Thesis
• Language: English
• Published: Memorial University of Newfoundland 2016
• Subjects: Newfoundland; Lithodes maja
• Online Access: https://research.library.mun.ca/12190/; https://research.library.mun.ca/12190/1/thesis.pdf

Natural resources in marine and coastal areas are of crucial economic importance for the province of Newfoundland and Labrador. They sustain the livelihoods and natural heritage of communities, and provide stable income for current and future generations, provided they are well-managed. Not all fisheries in Newfoundland and Labrador are fully exploited, and there are ongoing efforts to establish new sustainable industries in the province. For commercial fisheries, management requires a detailed assessment of the gear used in the fishery to ensure a sustainable industry. Assessing the effectiveness of fishing gears, and understanding the extent of fishing gear impacts on marine ecosystems, can provide unique protection for aquatic habitats and help ensure sustainability of marine species. In this study, I assessed a potential fishing gear for use in a northern stone crab (Lithodes maja: Linnaeus, 1758) fishery, and investigated how abiotic factors - water current direction, hourly variation in water current direction, turbidity and interspecific interractions, influence catch rates of this species, with the aid of an underwater video-camera. Results demonstrate that the Norwegian two-door pot is effective in capturing this species, and catch rates of this species is partly influenced by water current directions, hourly variation in water current direction and interspecific interactions of species. Turbidity had no effect on the catch rates of northern stone crab. In addition, there was little or no impact of the pot on the sea bed, there were no cases of escape and discard mortality, ghost fishing, lost pot, or injury to both target or non-target species in the study. Conscientious fishery management strategies remain essential in the effort towards ensuring sustainable existing and emerging commercial fisheries, as well as the benthic ecosystem.