Current status and future trends in kelp forest ecosystems

Abstract

Kelp forests dominate shallow rocky coasts of the world's cold-water marine habitats. They are comprised primarily of brown algae in the order Laminariales and produce one of the largest biogenic structures found in benthic marine systems. Kelp forest ecosystems include structure-producing kelps and their associated biota such as marine mammals, fishes, crabs, sea urchins, lobsters, molluscs, other algae and epibiota that collectively make this one of the most diverse and productive ecosystems of the world (Mann 1973, 2000; Dayton 1985a, b). Economically, kelp forest ecosystems have been significant to maritime peoples for thousands of years (Simenstad et al. 1978; Erlandson 2001). The aim of this chapter is to review how kelp forest ecosystems have changed at very large spatial scales over very long periods of time (decades to millennia). This perspective then provides a strong basis for assessing how different modern kelp ecosystems are from those in the past, and thus in turn allows an appreciation of possible future states.