Grant: Discovery Grants Program - Ship Time

The seafloor habitats of the Strait of Georgia and Saanich Inlet are in regions heavily exploited by transportation, resource extraction and estuarine outflows. Numerous government initiatives identify long-term concerns for ecosystem health in this intensely populated region. Since 2003 several kilometer-long, 5,000 year-old sponge reefs have been discovered in the Strait of Georgia. Although sponge reefs were abundant on shallow (<500m) continental habitats during the Jurassic, the Canadian reefs are the only modern representatives. The reefs are formed by glass sponges, which filter vast volumes of water for feeding and respiration each day, and may thereby dominate and exclude other suspension feeders. Deep sea corals occur throughout the NE Pacific, but only at particular sponge reefs. BC corals can live for decades to centuries. Their growth rates very among locations; but controls on their growth rates, and hence their time for recovery from human induced damage vary among locations along the coast. Growth rates and recovery times for reef-building sponges in BC waters are unknown, but will be studied using novel techniques. Our goals are to study the relative distributions of sponges and corals where they overlap, and to clarify the influences of temperature productivity, and current strength on biogeographic variation in coral and sponge growth rates.