Using next-generation sequencing techniques to assess adaptive capacity and illuminate mechanisms underlying the effects of high pCO2 on Alaskan crab and fish species
Why we care
Many economically important crab and fish species are negatively affected by exposure to ocean acidification predicted to occur throughout their ranges in the coming decades. Ocean acidification results in decreased growth, altered development, weaker exoskeletons, increased energy outputs, altered immune systems, altered behavior, and increased mortality in some of these species. Other stressors such as increased temperature can have interactive negative effects when combined with ocean acidification. Traditional laboratory experiments cannot duplicate the gradual changes that will affect species populations over multiple life-history stages and generations, so using next-generation genetic approaches provide insight into effects beyond specific life stages.
What we are doing
This study will use next-generation sequencing techniques to identify specific alterations in the molecular, metabolic, and physiological pathways of individuals exposed to ocean acidification. This is a way to identify pathways that impart tolerance to ocean acidification and warming. This project determines the effect of ocean acidification and thermal stress on gene expression in Pacific cod larvae and juvenile Tanner crab and identifies genetic markers indicating ocean acidification resilience.
Benefits of our work
Investigators will identify the cellular pathways that impart tolerance to ocean acidification. By comparing individuals that demonstrate low sensitivity to ocean acidification and with the general population, we enhance the ability to predict how adaptation will alter the species’ response to future ocean conditions. This research will inform the fishing industry and coastal, fisheries-dependent Alaskan communities about potential effects of ocean change on commercially important species. Outcomes can be used to drive future responses and adaptations in these industries regarding affected fisheries.
This project will expand the quantity and quality of ocean acidification (OA) monitoring across Northeastern U.S. coastal waters. The new OA data and incorporation of the world’s first commercial total alkalinity (TA) sensor into our regional observing system (NERACOOS) are designed to supply needed baseline information in support of a healthy and sustainable shellfish industry, and to aid in assessments and projections for wild fisheries. In working with partners to develop this proposal, clear concerns were brought forward regarding the potential impacts of increasing ocean acidity that extend from nearshore hatcheries and aquaculture to broader Gulf of Maine finfish and shellfish industries and their management. Stakeholder input and needs shaped the project scope such that both nearshore and offshore users will be served by TA sensor deployments on partner platforms, including time series data collection at an oyster aquaculture site, on the NOAA Ship of Opportunity AX-2 line, and on federal and State of Maine regional fish trawl surveys. In all, five different deployment platforms will be used to enhance ocean acidification monitoring within the Northeast Coastal Acidification Network (NE-CAN) with significant improvement in temporal and spatial coverage.
Adding the all-new TA measurement capability to the regional observation network will provide more accurate, certain, and reliable OA monitoring, and an important project objective is to demonstrate and relay this information to regional partners. Data products to be developed from the multi-year measurements include nearshore and offshore baseline OA seasonal time series as well as threshold indices tied to acidification impacts on larval production at the Mook Sea Farm oyster hatchery. An outreach and technical supervision component will include the transfer of carbonate system observing technologies to our partners and to the broader fishing industry, resource management, and science communities. NERACOOS will provide data management and communication (DMAC) services and work towards implementing these technological advances into the IOOS network.
The objective of this project is to make significant strides in bridging the gap between scientific knowledge and current management needs by integrating existing biogeochemical model frameworks, field measurements, and experimental work toward the goals of (1) delineating atmospheric and eutrophication drivers of Chesapeake Bay acidification and improve our understanding of estuarine carbonate chemistry, (2) developing a spatially explicit framework to identify shellfish restoration areas most and least prone to acidification impacts, and (3) better understanding feedbacks associated with future environmental conditions and shellfish restoration goals estuary-wide and within a model tributary. This effort includes (1) a field campaign to make the first comprehensive study of the spatial and temporal variability in the carbonate system in Chesapeake Bay, (2) experiments to quantify both carbonate and nutrient exchange between intact oyster reefs and the surrounding water while measuring response of these fluxes to reef structure and acidification, and (3) an advancement in numerical modeling tools to simultaneously simulate the dynamics of eutrophication, hypoxia, carbonate chemistry, and oyster reef growth and interaction with the water-column under present and future conditions.
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.