RAPID: Effect of a Very Low NAO Event on the Abundance of the Lipid-Rich Planktonic Copepod, Calanus Finmarchicus, in the Gulf of Maine

The copepod, Calanus finmarchicus, is a dominant member of the plankton in the Gulf of Maine, (GoM), despite its location at the southern edge of the species\u27 subarctic range. Wilkinson Basin, one of the three deep basins in the GoM, harbors very high concentrations of the early developmental stages of C. finmarchicus in the summer through winter and serves as a source of C. finmarchicus to GoM coastal ledges and banks. A recent study based on C. finmarchicus habitat characteristics across the North Atlantic predicts that climate-driven change will force the distribution of C. finmarchicus northward out of the GoM over the next several decades. However, the oceanographic and life history responses of C. finmarchicus to environmental variability in the Gulf are complex and largely unknown. The research in this RAPID proposal takes advantage of a rare opportunity to test a hypothesis about the control of C. finmarchicus abundance in the GoM from climate change related external forcing. The hypothesis states that a distinctly lower C. finmarchicus abundance follows, with a two-year lag, the occurrence of a very negative North Atlantic Oscillation (NAO). The specific processes that causally connect low C. finmarchicus with the NAO are not known. The research here tests the prediction that C. finmarchicus abundance will be very low in Wilkinson Basin in 2012, two years after one of the most negative NAOs on record, dating back to the 1860?s. Field observations in the form of a time series of measurements of hydrography, food availability and C. finmarchicus stage abundance will be taken at a fixed station in Wilkinson Basin and in the Maine coastal region, supported by measurements taken on the Scotian Shelf. A research survey, coordinated with a scheduled cruise in the Gulf of Maine in September, 2012, will take additional collections in Wilkinson Basin and throughout the GoM. Frozen and ethanol preserved samples of C. finmarchicus will also be collected for population genetic studies. The abundance results will be compared with historical time series and survey data collected over the past two decades, confirming or refuting the expectation of extreme NAO influence on GoM C. finmarchicus populations. The lipid-rich early developmental stages of C. finmarchicus represent a particularly important energy source for planktivorous fish such as herring, mackerel and sand lance, supporting coastal fisheries as well as the summer resident populations of the endangered North Atlantic right whale, which feeds on C. finmarchicus directly. This RAPID research provides information needed to understand sources of variability in C. finmarchicus supply to the GoM ecosystem and the data will be used to support the development of coupled physical-biological models of responses of the C. finmarchicus population to the NAO and other sources of external forcing. Archived samples will be used for genetic analyses addressing research questions about shelf-basin connectivity developed by the ocean sciences community in the U.S. BASIN Implementation Plan. The project contributes to the implementation of the observing subsystem for the Northeast Association for Coastal Ocean Observing Systems (NERACOOS), which has identified the need for observing change in zooplankton diversity as part of its regional build-out planning. It will also contribute to development of the story of C. finmarchicus as an asset for teaching marine science to K-12 students, through COSEE curriculum resources and the Cohen Center for Interactive Learning at the Gulf of Maine Research Institute

U.S.-GLOBEC: NWA Georges Bank: Effects of climate variability on Calanus dormancy patterns and population dynamics in the Northwest Atlantic

Calanoid copepods are key organisms throughout the world\u27s oceans, consuming primary and secondary production at high rates, and serving as prey for invertebrates, larval and small pelagic fish, seabirds, and marine mammals. Many of the most abundant copepods in temperate and high latitudes, including Calanus finmarchicus in the Northwest Atlantic, can spend part of their life cycle in dormancy, a state of suppressed development. During dormancy, copepods escape unproductive surface waters and reside in deep water for several months, after which they emerge and migrate to the surface, usually prior to the spring bloom. The timing and abundance of copepods emerging from dormancy set initial conditions for population growth in the active season and is likely critical for both copepod population dynamics and for feeding and growth of larval fish. Similarly, the timing of entry into dormancy and consequent reduction of prey availability in surface waters, may be important to population dynamics of surface planktivores. The physical and biological factors that control onset of and emergence from dormancy are not known for Calanus finmarchicus or other open ocean copepod species.This project aims to identify the factors that control onset of and emergence from dormancy in Calanus finmarchicus in the Northwest Atlantic using both an inter-regional comparison of dormancy response and associated environmental conditions and individual-based model (IBM) simulations. The research tests the hypothesis that inter-regional differences in population dynamics are caused by different environmental conditions acting on copepods with similar dormancy and physiological rate responses to environmental parameters. Data sets from seven regions of the Northwest Atlantic will be compiled and compared to observational bio-physical data sets to test hypotheses about dormancy control mechanisms. IBM simulations will be run in individual regions to test the plausibility of the refined dormancy control hypotheses. IBM simulations will also be run to test the sensitivity of the model to uncertainty in dormancy and physiological rate functions, and to evaluate population responses to realistic interannual variability in surface and deepwater temperature and shifts in the timing and magnitude of the spring bloom. Modeled population responses to climate variability in C. finmarchicus will be compared to similar ongoing analyses in C. pacificus and C. marshallae. The results of the proposed research will be important for understanding basic processes that influence seasonal production of a major group of plankton. This knowledge is critical to understanding the overall trophic impact of climate change on food webs of both the Northwest Atlantic and Northeast Pacific. The proposed research involves the direct participation of one Master\u27s level graduate student and one postdoctoral student. This research represents a continuing collaboration between scientists from the University of New Hampshire and NOAA\u27s Pacific Fisheries Environmental Laboratory (PFEL), and it includes collaborations with scientists at Dalhousie University and Canadian Department of Fisheries and Oceans Laboratories. In addition, the results expected from this proposal will be applicable to current and proposed GLOBEC copepod population modeling efforts. The information gained from this work will prove valuable to management for marine mammals (northern right whale that feeds primarily on C. finmarchicus), as well as cod, herring and other fish species on Georges Bank and in the Gulf of Maine and for the understanding of impacts of climate change on these species

US-GLOBEC NEP Phase IIIa: Efffects of Climate Variability on Calanus Dormancy Patterns and Population Dynamics within the California Current

Calanoid copepods are key organisms in the California Current (CC) region, consuming primary and secondary production at high rates and serving as prey for larval, juvenile, and small pelagic fish, other invertebrates and certain seabirds. A critical period in the life of several calanoid species is their overwintering period, during which they leave the unproductive surface waters in mid-summer to fall and then ascend to the surface in the springtime, usually coincident with the spring bloom. However, the physical and biological cues that both initiate and terminate the dormant phase of several key copepod species within the CC are poorly known. The goal of this research is to test the hypothesis that the dormant phase of two major calanoid species, Calanus pacificus and Calanus marshallae, are in part controlled by changes in temperature and prey abundance. This hypothesis will be tested by two means. First, the existing data on relative stage abundance and vertical distribution of the two target species for four distinct locations along the west coast of North America will be compiled and compared to observational bio-physical datasets, many of which were collected as part of the GLOBEC NEP program. Second, an Individual-Based Model (IBM) for each of the two species will be developed, based on several different conceptual models of how temperature and prey availability control the dormancy response. This model will then be forced with climatological data and compared with the analysis of the field data. Further, this model will be used to test the sensitivity of each species\u27 population dynamics to initial conditions, interaction with the timing of the spring bloom, and expected levels of climate variability. Finally, variability in the local population abundance of these two species due to responses to local climate versus population advection due to large-scale changes in physical transport will be addressed. The results of the research will be important for understanding some of the basic processes that influence the seasonal production of a major group of plankton. This knowledge is critical for understanding the overall trophic impact of climate change on marine food webs within the CC. This research involves a postdoctoral student and the information gained from this work should prove valuable to fisheries management for small pelagics and other managed invertebrate species. The results of this research will also be served to the public through a web-based Live Access Server system, thus making it readily and broadly available

U.S. GLOBEC: NWA Georges Bank - Processes Controlling Abundance of dominant copepod species on Georges Bank: Local Dynamics and Large-scale Forcing

A fundamental goal of Biological Oceanography is to understand how underlying biological-physical interactions determine abundance of marine organisms. For animal populations, it is well known that factors controlling survival during early life stages (i.e., recruitment) are strong determinants of adult population size, but understanding these processes has been difficult due to model and data limitations. Recent advances in numerical modeling, together with new 3D data sets, provide a unique opportunity to study the biological-physical processes controlling zooplankton population size. This project uses an existing state-of-the-art biological/physical numerical model (FVCOM) together with the recently processed large 3D data set from the Georges Bank GLOBEC program to conduct idealized and realistic numerical experiments that explore the detailed mechanisms controlling seasonal evolution of spatial patterns in dominant zooplankton species on Georges Bank. Hypotheses that address how dominant copepod species populations are maintained on the bank, including local dynamics and large-scale forcing will be examined. A specific goal is to determine whether the observed characteristic seasonal and spatial pattern of each species (long-term and inter-annual) is predictable from the interaction between its characteristic life-history traits and physical transport. The extent to which the copepod populations are controled by food-availability (bottom-up) or predation (top-down) processes will be examined, including the influence of Warm Slope Water versus Labrador Slope Water (NAO-dependent) on nutrient influx through the Northeast Channel and subsequent upwelling and biological enhancement on the bank. Self-sustainability of each species population on the bank itself and in the Gulf of Maine will be studied by controlling immigration from specific source regions. Large-scale forcing including NAO and catastrophic global warming (e.g. complete polar ice melt) will be examined explicitly by forcing the model at the boundaries, using scenarios based on basin-scale data and from concurrent basin-scale modeling efforts. This modeling study will provide new insights into the role of local and large-scale processes controlling zooplankton abundance in the ocean. The dominant copepod species to be studied include small species that are the dominant prey for larval cod and haddock in this region, thus providing critical information for concurrent larval fish modeling studies. This detailed, process-oriented, regional-scale modeling with boundary forcing will lay the groundwork for integration with models of the entire ocean basin. The resulting model will be a legacy of the GLOBEC Georges Bank program by providing a powerful new tool for understanding how local and large-scale forcing interact to control plankton production in the sea. Results of the proposed work will be broadly disseminated to the general oceanographic community, the fishing industry, K-12 institutions, and to the population at large, through web-based servers using existing infrastructure. Web-based users will be able to access model results and run the model using chosen parameter settings to obtain predictions of currents, hydrography, and plankton abundance patterns given selected climate forcing scenarios. Collaboration with the WHOI/UMASS COSEE program will foster communication with K12 students and the public both nationally and internationally

Collaborative Proposal: CAMEO: Using interdecadal comparisons to understand trade-offs between abundance and condition in fishery ecosystems

The investigators will conduct a model-based investigation of the dynamics of a productive pelagic ecosystems in the Gulf of Maine. The middle trophic levels in highly productive marine ecosystems are typically dominated by a few species of pelagic fish, such as sardines and anchovies in upwelling environments or herring and/or capelin in temperate and subpolar regions. These species act as important conduits for energy to higher trophic levels, including larger fish, seabirds, and cetaceans. When abundant, small pelagics can exert significant pressure on their prey, typically large mesozooplankton. Small pelagic fish exhibit complex dynamics and managing these species under an ecosystem approach is challenging. This modeling study will track both the abundance and condition of representative copepods (Calanus finmarchicus, Centropages typicus), herring, and bluefin tuna. The investigators will use a rigorous comparison of conditions from the 1980s and 1990s to develop the model. They will examine the sensitivity of this ecosystem to changes in fishing pressure on the middle trophic levels and to changes in the magnitude and timing of primary production. They will also consider the impact of increased temperature on the ability of C. finmarchicus to accumulate lipids and alter the condition of herring and tuna.The project will lead to improved knowledge of ecosystems with productive food webs. It will also directly impact address issues related to the management of the herring resource in the Gulf of Maine. The investigators will examine the consequences of ignoring condition of zooplankton and fish, as is the case with the current stock assessment. They will also explore the dynamical properties of the model ecosystem and consider under what conditions it is possible to have both abundant and well conditioned herring

Ocean Acidification-Category 1- Impact of ocean acidification on survival of early life stages of planktonic copepods in the genus Calanus in the northern

While attention concerning impacts of predicted acidification of the world\u27s oceans has focused on calcifying organisms, non-calcifying plankton may also be vulnerable. In this project, the investigator will evaluate the potential for impacts of ocean acidification on the reproductive success of three species of planktonic copepods in the genus Calanus that are prominent in high latitude oceans. C. finmarchicus dominates the mesozooplankton biomass across much of the coastal and deep North Atlantic Ocean. C. glacialis and the larger C. hyperboreus are among the most abundant planktonic copepods in the Arctic Ocean. Previous research showed that hatching success of C. finmarchicus eggs was severely inhibited by increased CO2 and lower pH in seawater, but only tested at an extreme level. Preliminary results in the investigator\u27s laboratory indicate that hatching success of C. finmarchicus is substantially reduced at increased seawater CO2 concentrations corresponding to pH levels between 7.9 and 7.5. Predictions of likely decline of surface pH levels to 7.7-7.8 over the next century raise questions about impacts on Calanus population dynamics if these preliminary results are confirmed. C. finmarchicus, for example, is presently at the southern edge of its range in the Gulf of Maine. The combination of higher surface layer temperature and lower pH may inhibit reproductive success during the late summer/fall bloom, which the PI hypothesize is critical to sustain the overwintering stock in this region. The investigators will collect C. finmarchicus females from the Gulf of Maine and, with the assistance of Canadian colleagues, C. glacialis and C. hyperboreus females from the deep lower St. Lawrence Estuary. They will conduct laboratory experiments in which hatching success, development and growth of Calanus nauplius stages are measured in controls of natural seawater and at a series of treatments in which CO2 concentrations, pH and temperature are rigorously controlled to represent possible future states of the northern ocean. The investigators will measure present surface and deep pCO2 and pH across the Gulf of Maine, including its deep basins, during a research cruise. The study will evaluate the hypothesis that predicted levels of CO2 increase in the northern ocean will impact population dynamics of the Calanus species. Using the results from the research cruise and a recently developed 1-D, Individual-Based life cycle model, the PI will explore in detail scenarios of impact of higher temperature and lower surface and deep pH on population dynamics of C. finmarchicus in the Gulf of Maine.Broader impacts: The lipid-rich Calanus species are considered key intermediary links between primary production and higher trophic levels in North Atlantic and Arctic Ocean food webs. Impacts of higher surface temperature and lower pH on reproductive success may potentially lead to profound changes in energy transfer and structure of pelagic ecosystems in the northern oceans. In the Gulf of Maine, C. finmarchicus serves as primary prey for herring, sand lance, and mackerel, as well as the endangered northern right whale, warranting thorough evaluation of ocean acidification effects on its population dynamics. This research will provide cross discipline training to a graduate student and undergraduate student interns. Data will be deposited in a recognized data archiving center and results disseminated through presentations at scientific meetings and peer reviewed research articles. Public outreach will be planned as part of the Gulf of Maine Research Institute community activities, including learning opportunities associated with the Cohen Center for Interactive Learning directed at fifth and sixth graders in the state of Maine

Marine plankton phenology and life history in a changing climate : current research and future directions

© The Authors, 2010. This article is distributed under the terms of the Creative Commons Attribution-Noncommercial License. The definitive version was published in Journal of Plankton Research 32 (2010): 1355-1368, doi:10.1093/plankt/fbq062.Increasing availability and extent of biological ocean time series (from both in situ and satellite data) have helped reveal significant phenological variability of marine plankton. The extent to which the range of this variability is modified as a result of climate change is of obvious importance. Here we summarize recent research results on phenology of both phytoplankton and zooplankton. We suggest directions to better quantify and monitor future plankton phenology shifts, including (i) examining the main mode of expected future changes (ecological shifts in timing and spatial distribution to accommodate fixed environmental niches vs. evolutionary adaptation of timing controls to maintain fixed biogeography and seasonality), (ii) broader understanding of phenology at the species and community level (e.g. for zooplankton beyond Calanus and for phytoplankton beyond chlorophyll), (iii) improving and diversifying statistical metrics for indexing timing and trophic synchrony and (iv) improved consideration of spatio-temporal scales and the Lagrangian nature of plankton assemblages to separate time from space changes.This study was supported by NSF grants to R.J.: OCE-0727033, 0815838 and 0732152. NSF grants to A.C.T.: OCE-0535386, 0815051 and 0814413. NSF grant to J.A.R.: OCE 0815336

Rapid Climate-Driven Circulation Changes Threaten Conservation of Endangered North Atlantic Right Whales

As climate trends accelerate, ecosystems will be pushed rapidly into new states, reducing the potential efficacy of conservation strategies based on historical patterns. In the Gulf of Maine, climate-driven changes have restructured the ecosystem rapidly over the past decade. Changes in the Atlantic meridional overturning circulation have altered deepwater dynamics, driving warming rates twice as high as the fastest surface rates. This has had implications for the copepod Calanus finmarchicus, a critical food supply for the endangered North Atlantic right whale (Eubalaena glacialis). The oceanographic changes have driven a deviation in the seasonal foraging patterns of E. glacialis upon which conservation strategies depend, making the whales more vulnerable to ship strikes and gear entanglements. The effects of rapid climate-driven changes on a species at risk undermine current management approaches

Regulation of gene expression is associated with tolerance of the Arctic copepod Calanus glacialis to CO2-acidified sea water

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