Will a Warmer, More Acidic Ocean lead to increased Pseudo-Nitzchia bloom toxicity in the Southern California Bight?

PI: David Hutchins and Feixue Fu


Research Institution:      University of Southern California

PI First name, Last name:    David Hutchins and Feixue Fu

Phone:                                213 740 5616

Email:                                dahutch@usc.edu



Ocean acidification may have additional negative impacts on shellfish culturing and harvesting other than the well recognized direct deleterious effects on calcification and larval development.  For instance, the shellfish industry along the West Coast of the U.S. has also been heavily impacted by harmful blooms of the toxic diatom Pseudo-nitzschia spp., during which marine food web accumulation of the neurotoxin domoic acid has led to economic damage through harvesting closures.  Our recent work suggests that elevated seawater CO2 can strongly stimulate the production of domoic acid by Pseudo-nitzschia cells, leading to potentially much more toxic blooms.  Thus, anthropogenic enrichment of the ocean with CO2 (e.g., ocean acidification) could greatly exacerbate the already substantial damage that these harmful algal blooms do to commercially important species ranging from shellfish to finfish.  However, almost nothing is currently known about how the toxicity of Pseudo-nitzs

chia species will be affected by increasing CO2 in combination with other concurrent climate change variables, such as sea surface warming and changes in nutrient supplies and light fields.  Our Sea Grant-funded pilot project is examining domoic acid production by cultured and natural populations of local Pseudo-nitzschia species under simulated future ocean conditions of temperature, CO2 (pH), irradiance, and nutrient availability.  This information will allow marine resource managers and the aquaculture and fishing industries to better predict and help prepare for the potentially much more toxic harmful algal blooms that may occur in the future.


KEYWORDS:  Ocean acidification, Pseudo-nitzschia, domoic acid, toxins, harmful algal blooms

FUNDING AGENCY (if available):          California Sea Grant