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.
This project uses data from experimental studies on the biological effects of ocean acidification (OA), largely funded by NOAA's Ocean Acidification Program (OAP), to construct realistic population‐process models of marine finfish populations. The models are of an individual‐ based model (IBM) category that use detailed biological responses of individuals to OA. This tool synthesizes OA data in two different ways. First, it accumulates and connects data through mechanistic relationships between the environment and fish life‐history. Second, it allows exploration of the population‐level consequences of CO2 effects (the source of OA) which explicitly include population effects carried over from the highly sensitive early life‐stages (ELS). This information is fundamental to understanding the community and ecosystem effects of OA on living marine resources.
Project efforts are directed at two different, complimentary levels. At the more detailed, specific level, winter flounder – an economically important, well‐studied fish of Mid‐Atlantic to New England waters – will be used as a model subject. Prior studies on winter flounder, augmented by OAP‐funded experimental work at NOAA/NEFSC, will provide estimates of CO2 effects on key life‐history and ecological parameters (e.g., fertilization, larval growth, development, and survival). An IBM previously developed by the PIs will be updated and expanded to include OA effects on these parameters. The winter flounder OA‐IBM will be exercised by evaluating the responses of the ELSs of this species under multiple scenarios: high average levels of CO2 representing future oceans in shelf habitats; high and variable CO2 depicting future inshore, estuarine habitats; and covariances of CO2 with other environmental stressors (e.g., warmer waters, hypoxia). At a general level and applicable to other species, the project will develop a web‐based tool that allows users to add details from other marine finfish of the NE USA and OA‐affected processes as relevant OA data on those species become available.
In terms of the commercial value of its shellfish and its importance as a finfish breeding ground, the western Gulf of Maine (GOM) is certainly one of the most valuable ecosystems in the United States. Because over 80% of organisms landed in the GOM must utilize calcium carbonate during certain critical life stages, the effects of ocean acidification (OA) on ecosystems are a topic of increasing regional concern. This notion was accentuated by recent demands from marine industry stakeholders and the State Legislature in Maine who convened an Ocean Acidification Commission to study and mitigate the effects of OA. By nature of its cool temperatures and copious freshwater subsidies from both remote and local origins, the western GOM may be particularly sensitive to future acidification stresses (Salisbury et al, 2008; Wang et al, 2013). With the goals of 1) providing data critical for climate studies and local decision support, and 2) understanding of regional processes affecting acidification, we propose to maintain data collection efforts at and proximal to UNH-PMEL acidification buoy. We will deploy, maintain and recover the buoy and its suite of instruments that provide quality oceanographic and carbonate system data. We will supplement these activities with seasonal cruises that map surface regional pCO2 and several surface variables supplemented with hydrographic and optical profiles at six stations along the UNH Wilkinson Basin Line (aka Portsmouth Line), which runs orthogonal to the coast. This in turn will be supplemented with ancillary bottle sampling and all will be used in research aimed at understanding processes controlling the dynamically evolving carbonate system in the western GOM.
The Ecosystem Monitoring program of the Northeast Fisheries Science Center conducts four dedicated cruises per year covering the entire extent of the Northeast United States (NEUS). NOAA OAP provides funding for the processing of dissolved inorganic carbon (DIC) and total alkalinity (TAlk ) samples from two Ecosystem Monitoring cruises. As part of these cruises, water samples have been taken at a subset of locations and at a range of depths. The depth-discrete nature of this sampling is very important and provides data to complement the more intensive surface sampling conducted by the pCO2 sensors. These samples are used to measure DIC and TAlk and their analyses are conducted by AOML. In addition, samples for among lab comparisons have been collected. Nutrient samples are also taken and are analyzed at University of Maine.
Initially, these samples will be used for an analysis comparing the extent of ocean acidification on the NEUS compared to the late 1970's. Subsequently, these samples will be used to provide continued monitoring of the state of ocean acidification. In addition, these samples will be used to better understand the relationship between carbonate chemistry and nutrient speciation on the NEUS. While interpretation of this data is complex, a consolidated analysis is being undertaken to develop an “Ocean Acidification Indicator” for the Northeast Shelf. This metric will provide resource managers and vested stakeholders a concise interpretation of current and near-term expected conditions of acidification in the region. This project also coordinates and cooperates with a number of other regional partners in an attempt to fulfill the regional monitoring vision of National OA Plan.