The discovery in June of a single bed of rhodoliths, colorful marine algae that resemble coral, was made near Knight Island in Prince William Sound by scientists at the University of Alaska Fairbanks (UAF) School of Fisheries and Ocean Sciences (SFOS). Rhodolith beds have been found throughout the world's oceans, including in the Arctic near Greenland and in waters off British Columbia, Canada. But they have never been documented in Alaska waters.
"This is exciting because it represents a new type of habitat scientists had not identified before in Alaska," said Brenda Konar, associate professor of marine biology at SFOS and staff scientist with the West Coast and Polar Regions Undersea Research Center at UAF.
Rhodoliths belong to a group known as coralline red algae that deposit calcium carbonate within their cell walls to form hard structures that closely resemble beds of coral. But unlike coral, rhodoliths do not attach themselves to the rocky seabed. Rather, they drift like tumbleweeds along the seafloor until they grow heavy enough to settle and form brightly colored beds. And while corals are animals that filter plankton and other organisms from the water for food, rhodoliths produce energy through photosynthesis.
Globally, rhodoliths fill an important niche in the marine ecosystem, serving as a transition habitat between rocky areas and barren, sandy areas. Rhodoliths provide habitat for a wide variety of species, from commercial species such as clams and scallops to true corals. The discovery of rhodoliths in Alaska is likely to fuel the debate over the protection of seafloor habitats.