Research ProjectOysters and Multiple Stressors

Project Goal

To determine how exposure to stressors associated with climate change as juveniles could affect oyster growth and fitness into adulthood.

Description

Eastern oysters (Crassostrea virginica) are one of the most important species in Chesapeake Bay. They filter the water, their reefs form habitat for dozens of associated species, and they support economically significant fisheries and aquaculture facilities. As the Bay’s waters change over time, however, stressors such as hypoxia (low dissolved oxygen) and acidification (low pH) could threaten oyster populations. Studies have shown that juvenile oysters grown under hypoxia are generally smaller than oysters grown under normal oxygen conditions, but how those oysters fare later in life is unknown. Our work investigates how hypoxia and acidification might affect oysters over the long term, and thus how the ecology and economy of the Bay could be affected.

Oyster spat settled on adult shells
Oyster spat settled on adult shells

Our project has two main components. First, we’ll raise oysters in our laboratory system that allows us to alter the dissolved oxygen and pH of the water in which we’re growing the oysters. Different oysters will be exposed to different severities of these stressors, with some oysters experiencing high oxygen and normal pH as they grow, while others will be growing (or not!) under severely low oxygen and pH. Afterwards, we will collect a suite of measurements (e.g. size, shell strength, water filtration rates) to assess how well the oysters are doing.  The second component of our study will be to plant these oysters at sites around the Bay, and we’ll monitor their growth over two years to see how exposing them to stress as juveniles affects their growth and reproductive capabilities in adulthood.