Kelp forest ecosystems_ biodiversity_ stability_ resilience and future
Kelp is rich in dietary fiber, protein and iodine, potassium, magnesium and other minerals, eat seaweed can enhance the body's thyroid function, and promote the consumption of calories, weight loss and thus achieve the purpose of detoxification.
Kelp forest ecosystems: biodiversity, stability, resilience and future ROBERT S. STENECK1, MICHAEL H. GRAHAM2, BRUCE J. BOURQUE3, DEBBIE CORBETT4, JON M. ERLANDSON5, JAMES A. ESTES6, MIA J. TEGNER7† 1School of Marine Sciences, University of Maine, Walpole, ME 04573, U.S.A. (Steneck@maine.edu) 2Center for Population Biology, University of California, Davis, Davis, CA 95616, U.S.A. (email@example.com) 3Department of Anthropology, Bates College, Lewiston, ME 04240, U.S.A. (firstname.lastname@example.org) 4US Fish and Wildlife Service, Anchorage, AK 99503-6119, U.S.A. (Debbie_Corbett@fws.gov) 5Department of Anthropology, University of Oregon, Eugene, OR 97403-1218, U.S.A. (email@example.com) 6U.S. Geological Survey, University of California, Santa Cruz, CA 95060 U.S.A. (firstname.lastname@example.org) 7Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA 92093-0201, U.S.A. †Deceased. Background the western North Atlantic. Globally urchin-induced Kelp forests dominate shallow rocky coasts of the deforestation has been increasing over the past 2-3 world's cold-water marine habitats. They are comprised decades. Continued fishing down of coastal foodwebs of brown algae in the order Laminariales and include the resulted in shifting harvesting targets from apex largest organisms attached to the sea floor. Kelp forest predators to their invertebrate prey including kelp- ecosystems include structure-producing kelps and their grazing herbivores. The recent global expansion of sea myriad associated biota such as marine mammals, fishes, urchin harvesting has led to the widespread extirpation of crabs, sea urchins, mollusks, other algae and epibiota this herbivore and in places kelp forests returned but, for which collectively make this one of the most diverse and the first time, these forests are devoid of vertebrate apex productive ecosystems in the world. Economically, kelp predators. In the western North Atlantic, large predatory forest ecosystems have been significant to maritime crabs have recently filled this void and they have become peoples for thousands of years. the new apex predator in this system. Similar shifts from fish to crab dominance may have occurred in coastal Aims zones of the United Kingdom and Japan where large Past reviews rarely considered how kelp forest predatory finfish were extirpated long ago. ecosystems have changed at very large spatial scales over very long periods of time (decades to millennia). A Conclusion longer historical perspective allows us to see how kelp Over the past two centuries, commercial exploitation forest ecosystems have changed and possibly where they for export led to the extirpation of sea urchin predators are headed in the future. such as the sea otter in the North Pacific and predatory fishes such as cod in the North Atlantic. Thus it was not Approach / Methods until the large-scale removal of predators for export We review the conditions in which kelp forests markets did sea urchin abundances increase and kelp develop and where, why they become deforested. forests decline over vast areas. Despite southern Through case studies from southern California, the California having one of the longest known associations Aleutian Islands and the western North Atlantic we with coastal kelp forests, widespread deforestation is examine the ecology of these well-studied locations, rare. It is possible that functional redundancies among which also represent the widest possible range in kelp predators and herbivores make this most diverse system forest biodiversity. most stable. Such biodiverse kelp forests may also resist invasion from non-native species. In the species- Results / Major findings depauperate western North Atlantic, introduced algal Global distribution of kelp forests are competitors carpet the benthos and threaten future kelp physiologically constrained by light at high latitudes and dominance. There other non-native herbivores and by nutrients, warm temperatures and other macrophytes predators have become established and dominant at low latitudes. Within mid-latitude belts (roughly 40- components of this system. 60˚ latitude in both hemispheres) well-developed kelp forests are most threatened by herbivory, usually from sea urchins. For literally thousands of years overfishing and extirpation of highly valued vertebrate apex predators has triggered herbivore population increases, leading to local kelp deforestation. Over the past century, deforestation has become more wide-spread. This is most profound and has the most long-lasting impacts on species-depauperate systems such as those in Alaska and