Marine Ecosystem Dynamics and Biodiversity in the Face of Climate Change and Overfishing

Marine environments are experiencing un precedented stress from two globally interacting forces, climate change and overexploitation. Changing ocean circulation patterns, rising sea surface temperatures and ocean acidification, coupled with sustained declines in fish stock abundance and benthic integrity due to unsustainable fishing practices over several decades are drastically restructuring the distributions of marine taxa and thus community productivity, biomass and diversity. The research explores the additive and synergistic effects of these factors on marine biodiversity dynamics across two major regional sites in the Indo-Pacific and the Arabian Gulf from 2000 to 2023 using remotely sensed oceanography data combined with fishery dependent stock assessment data and spatial diversity indices to measure change in species richness, trophic status and biomass across different levels of climate and exploitation. Statistically significant losses of 34.7% mean species richness, a 2.1℃ increase in sea surface temperatures and corresponding poleward range shifts of 62% of observed taxa are noted in areas under heavy fishing pressure. Fish stock losses associated with climate were 2.8 times greater in overfished than in lightly fished reference areas. This research highlights increasing collapse in the strength of trophic cascades under synergistic warming and overexploitation, leading to a 33% increase in bioaccumulated neurotoxicants among top predators. This implies the necessity for integrated and adaptive management frameworks including spatial management planning with established marine protected area networks, science-based quotas, and climate conscious management regimes to protect marine diversity and provide food security in a warming world.