We are likely to see "winners", those species or individuals that are most resilient in the face of climate change, and "losers" those species or individuals that are least capable of robust performance under stressful conditions.  At present, we cannot predict winners and losers, and do not know whether responses to environmental stress are primarily driven by phenotypic plasticity, broad performance under different environmental conditions, or if there are genetic or epigenetic factors that can result in cross-generational directional changes in populations, resulting in more resilience under stressful conditions of OA.   This project has two objectives: 

1)  To test for cross-generational adaptation to the impacts of increasing ocean acidification on blue mussels, either through phenotypic acclimation or through heritable changes. 

2)  To determine if there are tradeoffs in growth and development across life stages in response to stress induced by ocean acidification in blue mussels.\

The results of our experiments can then be used to develop management practices for wild populations and more robust aquaculture practices for blue mussels. From an aquaculture perspective, if animals from certain source populations are more resilient to OA stress, those locations could be targeted for collection of wild seed that will produce resilient mussels in aquaculture leases.  Furthermore, the environmental characteristics of these advantageous site(s) could then be characterized to predict other sites that may also produce resilient mussels.  Overall, the data obtained from this proposed work could be used to enhance mussel culture, an economically important activity of growing importance in our region.

This proposal will quantify the sensitivity of a key forage fish in the Northwest Atlantic to the individual and combined effects of the major factors comprising the ocean climate change syndrome: warming, acidification, and deoxygenation. We will rear embryos of Northern sand lance Ammodytes dubius, obtained by strip-spawning wild adults from the Stellwagen Bank National Marine Sanctuary (SBNMS) through larval and early juvenile stages in a purpose- built factorial system at different factorial combinations of temperature, CO₂ and oxygen.

Our first objective is to quantify individual and combined effects of temperature × CO2 (year 1) and temperature × CO2 × DO (year 2) on A. dubius growth and survival. We hypothesize that warming in combination with high CO₂ (low pH)  will have additive or synergistically negative effects, whereas the addition of low DO as a third stressor will have stark, synergistically negative effects on all traits. Our second objective is to characterize the swimming behavior of A. dubius larvae that have been reared under combinations of elevated temperature × CO₂. We hypothesize that combined stressors will have synergistically negative effects on the development of larval sensory systems, which express themselves and can thus be quantified as changes in larval swimming behavior. Our third objective is to take advantage of the rare winter sampling activities for this project to quantify CO₂, pH, and DO variability in benthic waters on Stellwagen Bank through bottle collections and short-term sensor deployments. We hypothesize that bottom water pH and DO levels during the sand lance spawning season might be routinely lower than levels in surface waters.

The overall aim of this proposal is to identify molecular mechanisms and markers that segregate "Winners" from "Losers" in three regionally-important bivalve species. The proposed research will identify molecular markers and mechanisms associated with resilience to acidification in some of the most important bivalve species along the east coasts: the eastern oyster (Crassostrea virginica), the hard clam (Mercenaria mercenaria), and the blue mussel Mytilus edulis. Furthermore, identified genetic markers will be validated with the aim of providing the aquaculture industry with tools needed to produce superior crops.

We have three specific objectives:   

(1) To identify molecular processes involved in bivalve resilience to ocean acidification and to characterize genetic markers associated with resilience 

 (2) To  validate  the  ability  of  identified  markers  to  predict resilience towards acidification  

(3)   To determine the physiological cost of resilience   

This research has major implications for basic and applied science. It will determine molecular and physiological mechanisms and pathways involved in bivalve natural resilience to acidification and identify molecular features associated with resilience. This information is greatly needed for the management of wild fisheries and for the development of resilient varieties of aquacultured stocks. Resilient broodstocks will provide the industry with superior germline to face current and projected episodes of acidification in local waters.

Co-PI's Wahle (UMaine) and Fields (Bigelow Laboratory) join Co-investigator Greenwood (UPEI) in this US-Canadian collaboration. The proposed study is designed to fill knowledge gaps in our understanding of the response of lobster larvae to ocean warming and acidification across lobster subpopulations occupying New England’s steep north-south thermal gradient. The research involves a comprehensive assessment of the physiological and behavioral response of lobster larvae to climate model-projected end-century ocean temperature and acidification conditions. We will address the following two primary objectives over the 2-year duration of the proposed study:

(1)  To determine whether projected end-century warming and acidification impact lobster larval survival, development, respiration rate, behavior and gene expression; and

(2)  To determine whether larvae from southern subpopulations are more resistant than larvae from northern populations to elevated temperature and pCO2.