Creating sustainable fisheries and reducing overfishing, which scientists have identified as the most serious threat to marine biodiversity, are key priorities in protecting the world's oceans. Some fisheries have been managed sustainably, but many others have not. In the U.S., overfishing and habitat degradation have left many fish populations unable to produce maximal yields. Thousands of jobs and millions in revenue are lost as a result. In relatively well-managed fisheries there is often a poor understanding of fishing's effects on marine biodiversity and ecosystem health.
Fish are vital components of marine ecosystems.
Overfishing can have profound unintended effects, ranging from algal blooms that can destroy coral reefs to the starvation of seabird chicks that depend on fish for survival. We must also replace the strong existing incentives to overexploit with equally strong incentives to conserve. Because of the complexity of these ecosystems, the high level of natural variation of the ocean, and limited funds for research, uncertainty will remain. No-take reserves reduce economic pressures to overfish, protect marine ecosystems, and, ultimately, increase fishery yields. Stock assessments and projections of fishing effort are often wrong, but no-take reserves will protect fish populations and habitats.