442 / 2024-09-17 09:16:00

Impact of climate change on global catches of marine fisheries from 1971 to 2020

marine fishery; capture value; low-frequency Climateclimate indices; Biophysical Environmentbiophysical environment

Marine fisheries catches have significant economic, social, and cultural importance for coastal communities and nations worldwide. A comprehensive understanding of the dynamics of these fishing grounds is crucial for the efficient management of fisheries and the conservation of resources. In addition to overfishing and predation, oceanic conditions linked to climate variability have profound effects on catches of oceanic fish species. Based on the FAO and multiple physical and biogeochemical datasets, we investigated the relationship between major modes of climate variability (including PDO, ENSO, AMO and ATL3) and key fish species over ~5% of the total catch in five fishing grounds (North and Southeast Pacific, Northeast, Northwest and Southeast Atlantic) around the world. The results show that: (1) In the North Pacific fishing ground, both Alaska pollock and Pacific sardine showed a positive correlation with PDO, while Pacific chub mackerel exhibited a negative correlation. The negative correlation became more pronounced when lagging the fish catch by 3-5 years; (2) In the Southeast Pacific fishing ground, only the catch of Chilean jack mackerel exhibited a significantly negative correlation with ENSO; (3) In the Northwest Atlantic, Atlantic code, Atlantic herring and Atlantic menhaden all exhibited a significant negative concurrent association with AMO. The statistically significant correlations also emerged for all the selected key species in the Northeast Atlantic. However, the correlation with Atlantic herring shifted to positive; (4) In the Southeast Atlantic ground, all selected fish catch exhibits a robust negative correlation with ATL3, except for Pacific sardine.

Correlation and composite analysis revealed complicated impacts of environmental variability on fish distribution, migration and abundance. Firstly, an increase in SST creates a favorable spawning habit for warm water fish, such as Pacific sardine, Chilean jack mackerel and etc. Secondly, intense upwelling supplied sufficient nutrients to support plankton growth. As a result, juvenile fish can migrate along the boundary of the nutrient-abundant warm pool with high NPP, thus establishing highly productive fishing grounds. Thirdly, pelagic fish that rely on zooplankton presents inverse parabolic relationships (Wasp-waist control) with NPP. This means an elevated net primary production (NPP) increased zooplankton biomass, consequently boosting fish abundance. However, when NPP exceeds a specific threshold, feedback inhibition between phytoplankton and zooplankton leads to a decrease in zooplankton biomass, resulting in reduced fish catches.

Our research provided an integral view on response of oceanic fish catch, which can be used as a guild to establish the statistical forecast model.