TOWARD ECOSYSTEM-BASED MANAGEMENT OF MARINE MACROALGAE—THE BULL KELP, NEREOCYSTIS LUETKEANA

Abstract

Ecosystem-based management is predicated on the multifaceted and interconnected nature of biological communities and of human impacts on them. Species targeted by humans for extraction can have multiple ecological functions and provide societies with a variety of services, and management practices must recognize, accommodate, and balance these diverse values. Similarly, multiple human activities can affect biological resources, and the separate and interactive effects of these activities must be understood to develop effective management plans. Species of large brown algae in the order Laminariales (kelps) are prominent members of shallow subtidal marine communities associated with temperate coastlines worldwide. They provide a diversity of ecosystem services, perhaps most notably the fuelling of primary production and detritus-based food webs and the creation of biogenic habitat that increases local species diversity and abundance. Species of kelp have also been collected for a variety of purposes throughout the history of human habitation of these coastlines. The bull kelp, Nereocystis luetkeana, provides a clear example of how the development of sustainable harvest policies depends critically on an understanding of the morphological, physiological, life-history, demographic, and ecological traits of a species. However, for Nereocystis as well as many other marine species, critical biological data are lacking. This review summarizes current knowledge of bull kelp biology, ecological functions and services, and past and ongoing management practices and concludes by recommending research directions for moving toward an ecosystem-based approach to managing this and similarly important kelps in shallow temperate rocky reef ecosystems.