Description

Climate change has caused Earth’s atmosphere to increase by an average on 0.74°C while sea surface temperatures have increased by approximately 0.67°C. Tunas (Thunnus spp. and Katsuwonus pelamis) are highly migratory, environmentally sensitive, and commercially important species. Here, we investigate the relationships between sea surface temperature, chlorophyll-a, and tuna abundances in catch per unit effort (tonne/set) along the coast of southern California from 1959 to 2019 using purse seine fishery data obtained from the InterAmerican Tropical Tuna Commission (IATTC) and hydrographic CTD data obtained from California Cooperative Oceanic Fisheries Investigations (CalCOFI). Sea surface temperature, chlorophyll-a concentrations, and tuna abundances varied widely throughout the 60-year time period. There was a significant positive correlation between sea surface temperature and tuna abundance, but a significant negative correlation between chlorophyll-a and tuna abundance. However, in both analyses there was a weak R2 value suggesting other factors, such as large-scale climate indices including El Niño-Southern Oscillation (ENSO) and Pacific Decadal Oscillation (PDO), may play a role in tuna distribution and abundance along the coast of southern California.

COinS
 

Effect of Sea Surface Temperature and Chlorophyll-a on the Abundance of Tunas (Thunnus spp. and Katsuwonus pelamis) Along the Coast of Southern California

Climate change has caused Earth’s atmosphere to increase by an average on 0.74°C while sea surface temperatures have increased by approximately 0.67°C. Tunas (Thunnus spp. and Katsuwonus pelamis) are highly migratory, environmentally sensitive, and commercially important species. Here, we investigate the relationships between sea surface temperature, chlorophyll-a, and tuna abundances in catch per unit effort (tonne/set) along the coast of southern California from 1959 to 2019 using purse seine fishery data obtained from the InterAmerican Tropical Tuna Commission (IATTC) and hydrographic CTD data obtained from California Cooperative Oceanic Fisheries Investigations (CalCOFI). Sea surface temperature, chlorophyll-a concentrations, and tuna abundances varied widely throughout the 60-year time period. There was a significant positive correlation between sea surface temperature and tuna abundance, but a significant negative correlation between chlorophyll-a and tuna abundance. However, in both analyses there was a weak R2 value suggesting other factors, such as large-scale climate indices including El Niño-Southern Oscillation (ENSO) and Pacific Decadal Oscillation (PDO), may play a role in tuna distribution and abundance along the coast of southern California.

 

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