Evaluation of OA impacts to plankton and fish distributions in the Gulf of Mexico during GOMECC-4 with a focus on HAB-interactions
Why we care
Ocean change in the Gulf of Mexico, including acidification and eutrophication, can impact biodiversity and the flow of energy through ecosystems from microscopic phytoplankton to higher trophic levels like fish. These processes can impact the health of fisheries and coastal ecosystems. This project collects information to evaluate the links between ocean conditions and important species in the Gulf of Mexico.
What we are doing
During the 4th Gulf of Mexico Ecosystem and Carbon Cruise (GOMECC-4), scientists collect samples of phytoplankton, zooplankton, and ichthyoplankton to characterize fish distribution and abundance, larval fish condition and diet, microplastic abundance, and harmful algal bloom species. These collections coincide with measurements of acidification, oxygen, and eutrophication to make connections between ocean chemistry and biology.
Benefits of our work
This project will help characterize how changes in ocean conditions interact with biological processes like harmful algal bloom formation and ecosystem productivity that are important to local fisheries and stakeholders.
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.
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.
Deep-sea corals are widespread throughout Alaska, including the continental shelf and upper slope of the Gulf of Alaska, the Aleutian Islands, the eastern Bering Sea, and extending as far north as the Beaufort Sea. Decreases in oceanic pH and resulting decreases in calcium carbonate saturation state could have profound effects on corals dependent on the extraction of calcium carbonate from seawater for skeletal building. Corals will be affected differently depending on their skeletal composition (aragonite vs. calcite), geographical location, and depth. The aragonite and calcite saturation horizons are already quite shallow in areas of the North Pacific Ocean and are predicted to become shallower in the near future. The skeletal composition is known for only a few Alaskan coral species and may be composed of aragonite, calcite, high-magnesium calcite, or amorphous carbonate hydroxylapatite. Skeletons composed of high magnesium-calcite are the most soluble and consequently corals with high-magnesium calcite skeletons, particularly those residing at depths deeper than the saturation horizon, are most at risk to decreases in oceanic pH. At the completion of this project we will be able to provide a comprehensive risk assessment for all corals in Alaskan waters.
To date many studies of the effects of ocean acidification on fishes have suggested that fish are somewhat resilient to effects on factors such as growth and survival. However, these experiments have generally not included potential interactive stressors which may increase the sensitivity to acidification stress. Further, experiments on some species have demonstrated the OA stress has significant potential to disrupt sensory and behavioral systems in fishes which could compromise survival in natural settings. In this project we will focus on examining the potential for behavioral disruptions due to OA and the interactive stresses of OA and nutritional state on critical Alaskan groundfishes.
The aim of this project was to forecast effects of ocean acidification on the commercially important Alaska crab stocks including the Bristol Bay red king crab (BBRKC) fishery, which is part of a modern fisheries management program, the Bering Sea and Aleutian Islands (BSAI) crab rationalization program. To investigate the biological and economic impacts of OA, a linked bioeconomic model was developed that a) integrates predictions regarding trends over time in ocean pH, b) separates life-history stages for growth and mortality of juveniles and adults, and c) includes fishery impacts by analyzing catch and effort in both biological and economic terms. By coupling a pre-recruitment component with post-recruitment dynamics, the BBRKC bioeconomic model incorporates effects of OA on vulnerable juvenile crabs in combination with effects of fishing on the BBRKC population as a whole. Many types of projections under management strategies can be made using linked bioeconomic models.
We will examine the effects of OA conditions (elevated pCO2) on the adaptive response of a potentially vulnerable native marine mollusc species with ecological, economic and social importance in the Pacific Northwest: geoduck clams (Panopea generosa). Geoduck clam larvae will be exposed to normal and elevated pCO2 and surviving larvae will be assessed using genomic sequencing to determine changes in allele frequencies at single nucleotide polymorphisms throughout the genome, and changes in the frequency of methylation states (epialleles) throughout the epigenome. Existing ecosystem models of OA consider a species' response to increased pCO2 as a fixed attribute; however, interpretations of the effects of OA at the population level may shift substantially if species adapt to the new environment. Furthermore, we will gain a better understanding of how specific genetic and epigenetic variations influence phenotype and the ability of an organism to respond, giving us new insights into fundamental aspects of species adaptation to environmental change.