Ocean acidification

Toxic harmful algal blooms are an increasing problem globally, and the West Coast of the U.S. is no exception. In particular, massive neurotoxic blooms of the domoic acid-producing diatom Pseudo-nitzschia have recently appeared that are larger, more frequent, longer lasting, and much more toxic than any that have been historically recorded. In recent years, these blooms have caused extensive damage to our Dungeness crab fishery, and they pose an increasing threat to other shellfish and finfish industries. It has become clear that this unprecedented intensification of toxic domoic acid events is very likely linked to ocean environmental change. For instance, research in my laboratory has shown that ocean acidification can benefit the growth and increase the toxicity of many harmful algal bloom species, including Pseudo-nitzschia. At present day atmospheric CO2 concentrations, obtaining enough dissolved CO2from the water to support growth can be a problem for Pseudo-nitzschia, which can thus be “carbon dioxide-limited”, and so it may actually directly benefit from higher CO2 levels. There is a definite potential for future CO2 fertilization of more frequent and more intense toxic algal blooms. However, we are now realizing that to understand and predict how ocean acidification will influence harmful algal blooms, we also need to consider a number of other interacting global change impacts. These other direct and indirect human disturbances include sea surface warming, losses of dissolved oxygen, stratification of the surface ocean, and modification of natural nutrient cycles by urban and agricultural pollution. For instance, in addition to ocean acidification, we have also shown that ocean warming strongly promotes domoic acid production by Pseudo-nitzschia. I will discuss the complex network of interactions between ocean acidification and these many other global change multiple stressors that my lab group is currently working to understand, in order to help predict and perhaps mitigate the tremendously damaging toxic algal blooms that increasingly threaten our coastal fisheries and marine food webs.

Continue reading ‘How ocean acidification works hand-in-hand with warming and other global change stressors to promote toxic Pseudo-nitzschia harmful algal blooms along the West Coast’

Time: 25 September, 9:00am Europe Summer Time (Berlin, GMT+02:00)

Description: The fourth webinar of the Community of Ocean Action on Ocean Acidification will be held on Wednesday 25 September at 9h00 Central European Summer Time. Dr Peter Thor, Swedish Meteorological and Hydrological Institute (SMHI), will present on Sweden’s plans to address and support SDG14.3, including through a national ocean acidification monitoring programme (Voluntary Commitment #19499). This will be followed by a talk by Dr Dorothee Bakker, University of East Anglia, UK, who will present the Surface Ocean CO2 Atlas (SOCAT; Voluntary Commitment #20464). The presentations will be followed by a discussion about opportunities for the COA on OA to work together to advance progress on SDG 14.3

Continue reading ‘Upcoming webinar: Community of Ocean Action on Ocean Acidification’

Presented by: Dr. Micah Horwith, Washington State Department of Natural Resources, Aquatic Resources

Time: August 7, 10 to 11pm CEST

Description: In 2015, the Washington State Department of Natural Resources established the Acidification Nearshore Monitoring Network. This program – ANeMoNe – collects co-located data on water quality, shellfish, and aquatic vegetation at 10 intertidal sites that span greater Puget Sound and the Washington Coast. ANeMoNe is designed to support hypothesis-driven research through replicated field experiments, and to measure the progress of ocean warming and acidification over tidelands. Here, we offer a survey of work from across the network, which has explored 1) the effects of eelgrass on local water chemistry, 2) the potential of eelgrass as a refuge for shellfish, and 3) regional differences in pH and other parameters of water quality. Through persistent monitoring and limited-term experiments, ANeMoNe fosters collaboration between agency and academic scientists, tribes, and community members invested in understanding and planning for rapid environmental change.

Continue reading ‘C-CAN webinar: Understanding acidification risks across habitats through a 10-site intertidal network’