Physical Sciences and Mathematics Commons^™

Ocean Acidification-Category 1- Impact Of Ocean Acidification On Survival Of Early Life Stages Of Planktonic Copepods In The Genus Calanus In The Northern, Jeffrey A. Runge, John P. Christensen

University of Maine Office of Research Administration: Grant Reports

While attention concerning impacts of predicted acidification of the world's 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 …

Collaborative Proposal: Cameo: Using Interdecadal Comparisons To Understand Trade-Offs Between Abundance And Condition In Fishery Ecosystems, Andrew J. Pershing, Jeffrey A. Runge

University of Maine Office of Research Administration: Grant Reports

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 …

Understanding Copepod Life-History And Diversity Using A Next-Generation Zooplankton Model, Andrew J. Pershing, Frederic Maps, Nicholas Record

University of Maine Office of Research Administration: Grant Reports

Evolution has shaped the physiology, life history, and behavior of a species to the physical conditions and to the communities of predators and prey within its range. Within a community, the number of species is determined by both physical properties such as temperature and biological properties like the magnitude and timing of primary productivity, and ecological interactions such as predation. Despite well-known correlations between diversity and properties such as temperature, the mechanisms that drive these correlations are not well-described, especially in the oceans. The investigators will conduct a model-based investigation of diversity patterns in marine ecosystems, focusing on calanoid copepods. …

Cnh: Collaborative Research: Direct And Indirect Coupling Of Fisheries Through Economic, Regulatory, Environmental, And Ecological Linkages, Andrew J. Pershing, Yong Chen, Jeffrey Runge

University of Maine Office of Research Administration: Grant Reports

The productivity and resilience of fisheries are subject to a multitude of dynamic and interrelated influences that arise from complex coupling of fish populations with the natural and human systems of which they are a part. With few exceptions, fisheries currently are managed independently, ignoring important natural and human linkages among them. The biological productivity, sustainability, and consequently human benefits of complex fishery systems may be substantially increased if these linkages are better understood and if this understanding is applied to management. The American lobster (Homarus americanus), Atlantic herring (Clupea harengus) and Northeast multispecies groundfish fisheries in the Gulf of …

Dissertation Research: Eco-Evolutionary Effects Of An Aquatic Consumer: Linking Phenotypic Diversity To Community And Ecosystem Responses, Kevin S. Simon, Quenton Tuckett, Michael T. Kinnison

University of Maine Office of Research Administration: Grant Reports

This research addresses the interaction between ecological and evolutionary processes by examining the recent evolution of a common invasive fish species, the white perch, in lakes and the consequences of this evolution for community and ecosystem dynamics. White perch have successfully invaded lakes spanning a productivity gradient, which provides diverse selective pressures that may result in altered fish morphology, physiology and ecological role. Adaptation by these fish may, in turn, feed back to affect lake productivity and community structure through several ecological and chemical pathways. This project tests the hypothesis that this rapid evolutionary divergence within a single species has …

Cmg Collaborative Research: Interactions Of Phytoplankton With Dissipative Vortices, Peter A. Jumars, Lee Karp-Boss

University of Maine Office of Research Administration: Grant Reports

The aim of this project is to develop coordinated laboratory experiments and computational models to address a fundamental question in oceanography concerning magnitudes and mechanisms of turbulence effects on phytoplankton and other particles at the spatial scale of individual organisms. The importance of external energy in the form of turbulence in determining relative success of different kinds of phytoplankton dates to the seminal analysis of Munk and Riley (1952) and Margalef (1978). Margalef's "mandala" asserts that high nutrient concentrations and turbulence intensities favor dominance by diatoms, whereas low values favor non-red-tide dinoflagellates. Subsequent work has revealed a wide spectrum of …

Rapid: Assessing Tsunami Impacts On The Benthic Community Of Robinson Crusoe Island, Richard Wahle, Peter Petraitis

University of Maine Office of Research Administration: Grant Reports

This RAPID project will assess the subtidal ecological impacts of the tsunami that struck Robinson Crusoe Island on 27 February 2010 with support from the Biological Oceanography Program and the Office of International Science and Engineering/Americas. It will take advantage of baseline data collected as part of an ongoing Chilean research project. Robinson Crusoe Island belongs to the Juan Fernandez archipelago, some 600 km west of the coast of Chile in the southeast Pacific. The island group is unique for its high level of marine and terrestrial endemism, including a fishery for the prized Robinson Crusoe Island lobster, Jasus frontalis. …

Effects Of Trace Metal Limitation On Oxidative Stress In Zooxanthellae And Its Role In Coral Bleaching, Mark Wells, J. Malcolm Shick, Charles G. Trick, Walter Dunlap, Paul Long

University of Maine Office of Research Administration: Grant Reports

Coral bleaching has increased dramatically in frequency, severity, and geographic extent since the 1980s and this trend is anticipated to continue, causing major environmental and economic impacts in tropical regions. This bleaching - the loss by corals of their photosynthetic endosymbiotic dinoflagellates (zooxanthellae; Symbiodinium spp.) - involves increased oxidative stress arising from the combined effects of elevated temperature at high light intensities. Although the production of reactive oxygen species (ROS) in corals and phytoplankton is routine during daylight hours, the failure of antioxidant defenses in zooxanthellae becomes catastrophic under comparatively small changes in environmental temperature, because reef corals live close …

Rapid: A Unique Cruise Opportunity To Test The Effect Of Trace Metal Limitation On Oxidative Stress And Coral Bleaching, Mark L. Wells, J. Malcolm Shick

University of Maine Office of Research Administration: Grant Reports

Intellectual Merit. Coral bleaching has increased dramatically in frequency, severity, and geographic extent since the 1980's and this trend is anticipated to continue, causing major environmental and economic impacts in tropical regions. This bleaching, or loss by corals of their photosynthetic endosymbiotic dinoflagellates (zooxanthellae; Symbiodinium spp.), appears to result from increased oxidative stress arising from the combined effects of elevated temperature at high light intensities. However, the mechanisms underlying this failure are not understood. The premise of the PIs' current project entitled "Effects of Trace Metal Limitation on Oxidative Stress in Zooxanthellae and Its Role in Coral Bleaching" (OCE - …

Collaborative Research: Interannual Variability Of Coastal Phytoplankton Blooms In The Gulf Of Maine And Their Relationships To Local And Remote Forcings, David W. Townsend

University of Maine Office of Research Administration: Grant Reports

The aim of this proposal is to explore the interaction of remote climate based forcing with local forcing to impact phytoplankton blooms in coastal and shelf regions with a coupled biological-physical model. Phytoplankton bloom dynamics are a classic example of biological-physical interactions in the ocean (Gran and Braarud, 1935; Sverdrup, 1953). Yet it is still a challenge to identify the dominant processes controlling the interannual variability of phytoplankton blooms in coastal and shelf seas where multiple-scale biological and physical processes interact. The unstructured-grid, finite-volume, coastal ocean model (FVCOM, built within the GLOBEC Georges Bank Program) bridges the multi-scale physical processes …

U.S. Globec: Nwa Georges Bank - Processes Controlling Abundance Of Dominant Copepod Species On Georges Bank: Local Dynamics And Large-Scale Forcing, Jeffrey A. Runge

University of Maine Office of Research Administration: Grant Reports

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 …

U.S.-Globec: Nwa Georges Bank: Effects Of Climate Variability On Calanus Dormancy Patterns And Population Dynamics In The Northwest Atlantic, Jeffrey A. Runge

University of Maine Office of Research Administration: Grant Reports

Calanoid copepods are key organisms throughout the world's 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 …

Itr: A Computational Framework For Observational Science: Data Assimilation Methods And Their Application For Understanding North Atlantic Zooplankton Dynamics, Andrew J. Pershing

University of Maine Office of Research Administration: Grant Reports

This project will develop a modular data assimilation system, investigate several algorithms to make data assimilation more efficient, and will apply this system to investigate zooplankton dynamics in the North Atlantic. The goal of data assimilation is to find the value of the control variables (typically, the initial conditions or boundary conditions or model parameters) producing the best agreement between the model and the data. A data assimilation system consists of a forward model representing known dynamics. This model is integrated and the deviation between its predictions and available observations are quantified by a cost function. An adjoint model, representing …

Us-Globec Nep Phase Iiia: Efffects Of Climate Variability On Calanus Dormancy Patterns And Population Dynamics Within The California Current, Jeffrey A. Runge

University of Maine Office of Research Administration: Grant Reports

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 …

Collaborative Proposal: Form And Function Of Phytoplankton In Unsteady, Low Reynolds-Number Flows, Peter Jumars, Lee Karp-Boss

University of Maine Office of Research Administration: Grant Reports

Small-scale flow dynamics at low Reynolds numbers (Re) are important to phytoplankton cells in delivery of nutrients, sensory detection by and physical encounter with herbivores, accumulation of bacterial populations in the "phycosphere" or region immediately surrounding phytoplankton cells and coagulation of cells themselves as a mechanism terminating blooms. In nature most phytoplankton experience unsteady flows, i.e., velocities near the cells that vary with time due to the intermittency of turbulence and to discontinuous, spatially distributed pumping by herbivores. This unsteadiness has not previously been taken into account in models or measurements with plankton. Moreover, there have been decade- and century- …

Globec Nep: Satellite-Observed Ocean Climate Variability, Andrew C. Thomas

University of Maine Office of Research Administration: Grant Reports

The PIs will extend in time and expand in scope the satellite data development and satellite-based analyses of ocean climate variability in the Northeast Pacific (NEP), begun during the GLOBEC Pilot Project phase (1997 - 00). The overall scientific problem is to characterize and quantify the dominant modes of variability in the NEP as embodied by satellite measurements of surface transports, temperature and chlorophyll patterns. Our analyses address multiple spatial and temporal scales using merged satellite data products over GLOBEC target study regions in both the California Current (CCS) and the coastal Gulf of Alaska (CGOA).

GLOBEC NEP field studies …

Linking Bioturbation And Sensory Biology: Chemoreception Mechanisms In Deposit-Feeding Polychaetes, Sara M. Lindsay, Paul Rawson

University of Maine Office of Research Administration: Grant Reports

Soft-sediment benthic habitats are ubiquitous in the marine environment and typically feature macrofaunal assemblages that include large numbers of deposit-feeding invertebrates such as polychaetes, bivalves, gastropods, crustaceans, holothurians, and hemichordates. Via their feeding, modulated in part by chemoreception, these organisms have profound effects on the ecology, biology, geology, and chemistry of their habitats. Very little is known, however, concerning the physiology and molecular biology of chemoreception in deposit feeders.

This research is a comprehensive investigation of the sensory mechanisms coordinating chemoreception in deposit feeding spionid polychaetes. It directly addresses this lack of information and will therefore have a significant impact …

Food Substrates And Digestive Capabilitites Of Marine Deposit Feeders, Lawrence M. Mayer

University of Maine Office of Research Administration: Grant Reports

Deposit feeders play several important roles in determining whether organic material is demineralized or buried. These animals function to make surfaces available for microbial growth and move particles both horizontally and vertically within the seabed at a pace that far exceeds sedimentation. The central problem in understanding deposit feeders is to identify the materials that they utilize and to determine the sources of those materials. The interdisciplinary approach of this project is to combine a chemical reactor theory of digestion with measurements of the processing of enzymatically available amino acids, focusing on rates of hydrolysis in, and absorption from, the …

Remote Sensing Of The Ne Pacific: Retrospective And Concurrent Time Series Analysis Using Multiple Sensors On Multiple Scales, Andrew C. Thomas

University of Maine Office of Research Administration: Grant Reports

A significant number of physical and biological variables covary within and between the boundary currents of the subarctic and subtropical gyres in the NE Pacific Ocean. These (summarized in US GLOBEC Reports 17, 11 and 7) include the strength of the transports, surface temperatures, zooplankton biomass and the catch of commercially important fishes. Time scales range from individual events to interdecadal regime shifts. The mechanisms by which these physical and biological fields covary are unknown, but it is postulated that the same mechanisms involved in interannual variability also affect long term climatic variability. Clarification and quantification of the mechanisms governing …

New And Export Productivity Regulation By Si And Fe In The Equatorial Pacific Ocean, Fei Chai

University of Maine Office of Research Administration: Grant Reports

To identify and quantify the principal processes that control the partitioning of carbon among oceanic reservoirs and between the ocean and atmosphere on focal and regional scales, with a view towards synthesis and prediction on a global scale, is a specific goal of the U.S. JGOFS Synthesis and Modeling Project. As a contribution towards achieving this goal, Drs. Barber, Peng, Chai and Dugdale will develop an ecosystem model for the equatorial Pacific Ocean, with a focus on how silicate and iron affect new and export productivity and the partitioning of carbon between the atmosphere, surface ocean and deep ocean. The …

Emersion Stress In Intertidal Seaweeds: Role Of Active Oxygen, Ian R. Davison

University of Maine Office of Research Administration: Grant Reports

The study will examine stress-tolerance in two major groups of perennial intertidal macroalgae, the red and brown seaweeds. The research will test the hypothesis that active oxygen is involved in emersion stress of intertidal seaweeds. Damage due to active oxygen will be determined in stress-tolerant and stress- susceptible species exposed to emersion stress by measuring the peroxidation of membrane lipids. Plants will be grown in laboratory culture under conditions that increase their ability to withstand emersion stress. If the research hypothesis is correct, increases in stress tolerance should be associated with increased levels of antioxidants and/or protective enzymes. The proposed …