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.

Why we care

Winter flounder are a commercially harvested finfish that occur within the Mid-Atlantic Bight and support fisheries in several U.S. states. Understanding the potential or realized effects on ocean acidification (OA) on this fish and the implications on fished populations is essential for building resilience for this fish and the people who depend on them. This project makes the link between experimental results on the effects on winter flounder and populations using a modeling approach.

What we're doing

We are using data from experimental studies of the effects of ocean acidification on winter flounder to construct realistic population-process models of marine finfish. 

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.  

The project directs efforts 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. Past work provides estimates of CO₂ effects on key life‐history and ecological parameters (e.g., fertilization, larval growth, development, and survival) that will enhance and update the model to include these parameters. We will evaluate the winter flounder OA‐IBM 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).  

Benefits of our work

The models help resource managers and others assess and predict the potential impacts of ocean acidification on winter flounder. The project will produce a web‐based tool that allows users to add details from other marine finfish of the northeaster 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.