Kelp forest

Kelp forests are underwater areas with a high density of kelp, which covers a large part of the world's coastlines. Smaller areas of anchored kelp are called kelp beds. They are recognized as one of the most productive and dynamic ecosystems on Earth.^[1][2] Although algal kelp forest combined with coral reefs only cover 0.1% of Earth's total surface, they account for 0.9% of global primary productivity.^[3] Kelp forests occur worldwide throughout temperate and polar coastal oceans.^[1] In 2007, kelp forests were also discovered in tropical waters near Ecuador.^[4]

Physically formed by brown macroalgae, kelp forests provide a unique habitat for marine organisms^[6] and are a source for understanding many ecological processes. Over the last century, they have been the focus of extensive research, particularly in trophic ecology, and continue to provoke important ideas that are relevant beyond this unique ecosystem. For example, kelp forests can influence coastal oceanographic patterns^[7] and provide many ecosystem services.^[8]

However, the influence of humans has often contributed to kelp forest degradation. Of particular concern are the effects of overfishing nearshore ecosystems, which can release herbivores from their normal population regulation and result in the overgrazing of kelp and other algae.^[9] This can rapidly result in transitions to barren landscapes where relatively few species persist.^[10][11] Already due to the combined effects of overfishing and climate change,^[12] kelp forests have all but disappeared in many especially vulnerable places, such as Tasmania's east coast and the coast of Northern California.^[13][14] The implementation of marine protected areas is one management strategy useful for addressing such issues, since it may limit the impacts of fishing and buffer the ecosystem from additive effects of other environmental stressors.