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. 

The primary goal of our OA projects (NEFSC Howard Laboratory) is to understand the impacts of increased CO2 and acidity of ocean and estuarine waters on important finfish species of our region. Our tactical objectives during FY12-14 were to develop, test, and then implement an experimental system that allows for the estimation of impacts of high CO2 and associated increased acidity of marine waters on the ELS of economically and ecologically important finfish species important to the NE USA. In FY15-17 we are building upon investments in research capacity and knowledge, and our experiments are addressing higher order questions that fold very well into one of the goals of the Interagency Working Group on OA – undertaking research to examine species-specific and multi-species physiological responses including behavioral and evolutionary adaptive capacities. We have four higher level objectives for our FY15-17 studies. 

First, we are testing our hypothesis that the resilience of the individuals in a population is inversely related to the variability of the CO2 in the habitat the population occupies (see also, Murray et al. 2014). This evaluation is being done by conducting comparative experiments among winter flounder from separate and distinct source populations whose resident habitats differ in characteristic levels and stability in CO2. Second, we are evaluating the role of parental exposure in the resilience / susceptibility of offspring to elevated CO2 (Sunday et al. 2014, Malvezzi et al. 2015). For these transgenerational studies, we are using three different forage species (original intent was to use Atlantic cod broodstock housed at the University of Maine but logistics and staffing decisions there precluded our use of those fish). Third, we are expanding our synthesis and meta-analysis of biological effects of CO2 on finfish. Lastly, we continue our education and outreach efforts on OA themes by mentoring students, conducting surveys, and providing tours of our OA experimental facilities.