Sponge Reefs of the British Columbia, Canada Coast: Impacts of Climate Change and Ocean Acidification

• Published in: Climate Change, Ocean Acidification and Sponges pp. 429 - 445
• Main Authors: Conway, K. W., Whitney, F., Leys, S. P., Barrie, J. V., Krautter, M.
• Format: Book Chapter
• Language: English
• Published: Switzerland Springer International Publishing AG 2017; Springer International Publishing
• Subjects: Deep water; Ecological science, the Biosphere; Hexactinellids; Hydrology (freshwater); Hypoxia; Porifera; THE ENVIRONMENT
• ISBN: 3319590073; 9783319590073
• DOI: 10.1007/978-3-319-59008-0_10

Sponge reefs living in deeper shelf waters on the western margin of North America are somewhat insulated from surface water effects of localized ocean warming but are susceptible to increasing hypoxia associated with ocean stratification and increasing upwelling. The largest reef complexes are projected to experience increasing upwelling and low-oxygen events in the future as part of the observed and projected changes in ocean ventilation accompanying increased atmospheric carbon dioxide concentrations. Inshore and shallow reefs are subjected to surface water warming in fiords. Surface water productivity is anticipated to change slightly likely having limited negative impact on the sponge reefs which are adapted to relatively low-nutrient situations. It is unknown the extent to which glass sponges might be resilient to lower oxygen conditions. While filtration is an energetically costly method of feeding, glass sponges appear to be adapted to reduce their energetic needs by using ambient flow to assist filtration. Populations that experience extreme hypoxia in some fiords may be extirpated by extreme anoxic events. Ocean acidification will not have as large an effect on the siliceous skeleton sponges as it will on corals and other carbonate-dependent organisms though it is possible changing pH will affect tissue functioning and homeostasis by compromising membrane pumps. Hexactinellid sponges and sponge reefs have been resilient to changing climate and ocean environments in the geologic past.