Understanding what climate change means for local marine organisms
We all know that global climate change is altering our environment, but how exactly will marine ecosystems respond to these changes? Can we predict and anticipate these changes? These are the types of questions that Dr. Carol Blanchette, a marine ecologist at the Marine Science Institute and CMAP scientist, and her colleagues Gretchen Hofmann, Emily Rivest, and Lydia Kapsenberg, have been working on. They have been measuring parameters such as temperature and pH level changes along with the related biological responses to help us gain a better understanding of the consequences of global climate change for marine ecosystems.
Monitoring stations have been set up through the entire coast of Central California with a focus on intertidal and near shore marine ecosystems. These monitoring stations have been recording pH levels so that the potential effects of ocean acidification on key organisms can be better understood. Through these monitoring stations, we are learning that pH levels are not nearly as homogenous across an ecosystem as previously believed. The research is finding a prominent difference in the patterns of the variability of pH levels. This means that marine organisms in these ecosystems are already experiencing a large fluctuation of pH levels.
Recently, Dr. Blanchette has been specifically focusing how these changes in pH levels are affecting key shell forming species. Both sea urchins and mussels are especially susceptible to ocean acidification because the resulting lower calcium carbonate saturation levels makes it more challenging for these species to build and retain their shells.
Sea urchin larvae were studied in an array of pH levels. While the sea urchins in more acidic water seemed healthy, they had smaller body sizes compared to those in more basic salt water. It remains to be determined what this means long term for sea urchins. It is possible that the smaller size could hinder reproduction.
In addition to analyzing body size, there was a detailed review of the sea urchins’ genes. It appears that the genetic codes are changing over time. The sea urchins are able to quickly adapt to changes in the atmosphere and pass on beneficial changes in their DNA structure. This indicates that sea urchins may have a high evolutionary potential. Their genetics can change quickly through generations, demonstrating that the sea urchins could adapt to changes in pH over time. Dr. Blanchette will next be conducting similar experiments with mussels.
While our local marine ecosystems are highly complex, understanding how key species will be affected by climate change will help us to better plan and prepare for these changes. Solid scientific knowledge will need to be combined with sound planning by local communities to best manage our local fisheries and ocean environment during a quickly changing climate.