Assessing the Impact of Fisheries and Aquaculture on Ecosystem Integrity and Biodiversity

Abstract

Background: Fisheries and aquaculture represent the largest producers of animal protein from aquatic environments worldwide, yet the impact of the two together on ecosystem structure and diversity is poorly quantified. Both sectors are growing rapidly and require scientific data and rigorous analysis to allow management to adapt to changes and allow their impacts to be understood and reduced. Methods: An extensive systematic review and meta-analysis of literature from 2015-2024 was undertaken, incorporating a range of ecological indices, including measures of species richness, Shannon diversity, benthic health (using benthos integrity scores), and mean trophic level across both marine and freshwater systems under conditions of differing fisheries intensity and aquaculture presence. Results: Data from published works show a significant reduction in mean trophic level (0.3-0.7 units) in highly exploited wild-capture fisheries, and a reduction in species richness by up to 38%. Standard aquaculture practices include both nutrient loading and oxygen depletion, as well as a reduction in the biodiversity present as a result of escapees becoming a genetically assimilated, dominant species. Significantly reduced impacts from IMTA and RAS were observed, with most diversity indices returning values closer to reference conditions. Conclusions: Movement towards both ecosystem-based fisheries management and low-impact, land-based technologies is essential to conserve the aquatic ecosystem. The policy, stakeholder interaction, and investment required needs attention now.