Along the world’s rocky, temperate coasts, floating canopies of large kelp tower over the seafloor to provide refuge, forage grounds and nurseries for a dizzying array of marine animals. Both floating and understory kelp species act as foundations and engineers that transform rocky nearshore waters into some of the most diverse ecosystems on the planet, even competing with tropical rainforests in terms of total productivity.
In the Puget Sound the canopy forming bull kelp (Nereocystis luekteana) conspires with over 20 other understory kelp creating underwater forests unique to our region. These forests attract juvenile rockfish and salmon that use the tangle of large kelp fronds as safe refuge and all-you-can-eat buffets.
The constant detritus produced by the frayed ends of long kelp blades provide ample food for filter feeders, while small grazing invertebrates opt to dine-in, often using kelp blades as both a home and food source.
Human beings are no exception when it comes to using and eating kelp. New research suggests that the first humans to reach North America traveled a “kelp highway” of sheltered, calm waters that stretched along the coast from Japan to Alaska. Today, global seaweed aquaculture is valued at over $6 billion annually. While a bulk of that production occurs in China and Korea, there is growing interest in North America with the Northeastern states of Maine and Connecticut leading the charge.
Unfortunately, kelp forests throughout the world are in decline as water temperatures continue to rise and coastal food webs are disrupted from over-fishing. In recent decades, land managers, fishermen and residents throughout the Puget Sound have reported increased losses to floating canopies. As a direct result of these alarming reports, work has begun to develop priority recommendations for kelp conservation, recovery and restoration in the Puget Sound.
Part of this recovery and conservation strategy focuses on promoting increased kelp aquaculture in the Puget Sound for the production of restoration stock and to create sustainable economic opportunities to coastal areas throughout the state.
Additionally, there is growing evidence that kelp aquaculture may benefit the Sound by buffering against ocean acidification and helping remove excess nutrient pollution. The course will begin with a brief primer on the unique biology and ecology of kelp before discussing the current state and trends of Puget Sound kelp forests and potential causes of decline. In addition, this course will explore the potential role of kelp aquaculture in providing similar ecosystem services to natural beds.