Shellfish Response to a Warming Environment: a Mesocosm Experiment

Principal Investigator: Candace Oviatt (GSO, URI), Roxanne Beinart (GSO, URI) and Conor McManus (RIDEM DMF)

Funding Source: Rhode Island Sea Grant

How shellfish in Narragansett Bay will respond to climate warming has not been fully investigated because local shellfish are impacted by several concurrent environmental changes. Shellfish themselves don’t only face warmer waters, but also face changes in food availability as the changes in water temperatures and nutrient inputs into the Bay may impact primary production. Additionally, shellfish populations in the Bay may be impacted by sediment quality and legacy pollutants that could limit shellfish reproduction.

To better understand how each of these dynamics will impact shellfish, researchers at URI GSO and RIDEM are running a set of mesocosm experiments analyzing the growth, survival, and reproductive potential of quahogs (Mercenaria mercenaria) and awning clams (Solemya velum) in three treatments: 1) ambient seawater; 2) seawater 2°C warmer than ambient; and 3) seawater 2°C colder than ambient. The winter spring diatom bloom in the Bay is synthesized with the addition of essential nutrients at the beginning of the experiment and primary productivity is monitored throughout the experiment. The shellfish are also raised in sediment gathered from the Providence River area and in the comparatively clean mid Bay region to assess the impacts of legacy contaminants on the reproduction of the shellfish. This aids in the assessment of food availability on shellfish life stages of growth and reproduction. Through these mesocosm experiments, the researchers gather information on life history rates under current environmental conditions in the Bay.