Overfiske

Overfiske refers to the exploitation of fish stocks at a rate that prevents replenishment, leading to a decline in abundance. In fisheries science, overfiske occurs when fishing mortality exceeds the stock’s natural growth, or when catches exceed the level that can produce maximum sustainable yield (MSY). The term is used in Norwegian and Danish contexts to describe harvesting that is not sustainable over time.

Causes of overfiske include high demand for seafood, advances in fishing technology, and subsidies that support high catch levels. Weak governance, limited data for stock assessments, and illegal, unreported, and unregulated fishing also contribute. Climate change and shifting species distributions can complicate stock assessments and management, sometimes masking the true extent of depletion.

The consequences of overfiske are multi-faceted. Direct effects include shrinking population size, reduced recruitment, and lower biomass, which can threaten the long-term viability of the fishery. Indirect effects spread through ecosystems, affecting predator–prey relationships and habitat structure. Economic and social impacts often follow, with reduced catches harming fishing communities and regional economies. Notable historical examples include the collapse of several cod stocks in the North Atlantic during the late 20th century, which led to moratoriums and lasting changes in management.

Management responses aim to restore and maintain sustainable yields. Tools include science-based catch limits (TACs), data collection and stock assessments, rights-based management, gear restrictions, and marine protected areas. International and regional organizations work to coordinate effort, improve compliance, reform subsidies, and adopt precautionary, ecosystem-based approaches to ensure stocks recover and remain productive over time.