Exploring the impact of fishing and climate scenarios on the South African sardine and anchovy fishery.

This study explores the possible future impacts of environmental variability and climate change on the biomass and distribution of South African anchovy and sardine, and the associated implications for the small pelagics fishery using a Model of Intermediate Complexity for Ecosystems (MICE). This model includes biomass-based age- and ager-structured population dynamics for sardine and anchovy to account for the major life history migrations of these species and includes links between environmental variables and fish movement. In addition to movement, the model accounts for growth, recruitment, natural and fishing mortality, with the latter taking explicit consideration of the impact of juvenile sardine bycatch with directed anchovy fishing on future directed sardine catches. The model parameters were estimated by fitting to the hydro-acoustic survey recruit and total biomass data for 1987 2014, observed catches, and sea surface temperature (SST) and primary production data from 1987-2014. SST and primary production time series under scenario Shared Socioeconomic Pathway 5-8.5 from 2015-2050 were used for the projections.

This MICE provides an opportunity to consider forecasts of the impacts of predicted climate change, specifically sea surface temperature and primary production, on the southern Benguela anchovy and sardine. Such forecasts could assist the small pelagic fishery to improve their resilience and reduce their vulnerability to future environmental changes.