Kelp Forest - Threats and Management

Threats and Management

Given the complexity of kelp forests – their variable structure, geography and interactions – they pose a considerable challenge to environmental managers. It is difficult to extrapolate even well-studied trends to the future because interactions within the ecosystem will change under variable conditions, not all relationships in the ecosystem are understood, and there can be non-linear thresholds to transitions that are not yet recognized. With respect to kelp forests, major issues of concern include marine pollution and water quality, kelp harvesting and fisheries, invasive species and climate change. It has been argued that the most pressing threat to kelp forest preservation is the overfishing of coastal ecosystems, which by removing higher trophic levels facilitates their shift to depauperate urchin barrens. The maintenance of biodiversity is recognized as a way of generally stabilizing ecosystems and their services through mechanisms such as functional compensation and reduced susceptibility to foreign species invasions.

In many places, managers have opted to regulate the harvest of kelp and/or the taking of kelp forest species by fisheries. While these may be effective in one sense, they do not necessarily protect the entirety of the ecosystem. Marine protected areas (MPAs) offer a unique solution that encompasses not only target species for harvesting but also the interactions surrounding them and the local environment as a whole. Direct benefits of MPAs to fisheries (for example, spillover effects) have been well documented around the world. Indirect benefits have also been shown for several cases among species such as abalone and fishes in Central California. Most importantly, studies have demonstrated that MPAs can be effective at protecting existing kelp forest ecosystems and may also allow for the regeneration of those that have been impacted.