Life Sciences Commons^™

Rapid: Effect Of A Very Low Nao Event On The Abundance Of The Lipid-Rich Planktonic Copepod, Calanus Finmarchicus, In The Gulf Of Maine, Jeffrey A. Runge

University of Maine Office of Research Administration: Grant Reports

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' 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 …

Rapid: Natural Laboratories In The Chilean Fjords: Studying Reproduction And Development In Emergent Deep-Sea Corals, Rhian G. Waller

University of Maine Office of Research Administration: Grant Reports

Intellectual Merit

The northern Patagonian fjords lie on the interface between the high Andes Mountains in the east and the South Pacific Ocean, formed thousands of years ago through erosive glacial activity and tectonic sinking. Around 12,000 years ago the icefields in the Chiloé Interior Sea began to open, leaving behind over 15,000km2 of fjords, channels and gulfs. The waters within the fjords are influenced by strong tides, large volumes of freshwater runoff, and upwelling of deep-ocean waters as well as steep climatic gradients from north to south. This dynamic environment has resulted in extremely high biodiversity and endemism, yet …

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. …

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 …

Us Globec Nwa/Georges Bank: Processes Controlling Abundance Of Dominant Copepods On Georges Bank: Local Dynamics And Large-Scale Forcing, David W. Townsend

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 …

Sger: Investigation Of Potential Co-Introduction Of Fucus Serratus And Littorina Littorea To North America In 1800s, Susan H. Brawley

University of Maine Office of Research Administration: Grant Reports

This research will apply new approaches and expertise to understanding the probable invasion of North American intertidal zones by the herbivorous snail Littorina littorea in the 1800s. The investigator developed the following hypothesis during her recent analyses of late 1700s to mid-1800s shipping records: Fucus serratus and Littorina littorea were co-introduced into North America from Britain via the dumping of intertidal rock ballast in ships arriving at Pictou Harbor during the massive emigration of nearly 40,000 Scots (and some Irish and English) in the late 1700s-mid-1800s. This hypothesis will be tested using innovative molecular techniques (i.e., assay of nuclear …

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- …

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 …

The Effect Of Gamete Competition On Levels Of Gamete Production In A Marine Invertebrate, Kevin J. Eckelbarger

University of Maine Office of Research Administration: Grant Reports

Previous work suggests that high population densities result in more intense male gamete competition and select for increased levels of production of these gametes. This hypothesis will be tested by examining spatial and temporal correlations between density and male gamete production levels in natural populations of a colonial ascidian. Two additional considerations which might modify the effect that male gamete competition has on levels of male gamete production will also be explored. First, natural selection can only act on the genetic portion of total phenotypic variance. Secondly, selection acts simultaneously on the entire phenotype, and so the effect of selection …

Powre: A Pilot Study Of Chemoreception Mechanisms In Deposit-Feeding Polychaetes, Sara M. Lindsay

University of Maine Office of Research Administration: Grant Reports

This proposal was submitted to the NSF-wide Professional Opportunities for Women in Research and Education (POWRE) program. The PI proposes to begin research on the sensory mechanisms coordinating chemoreception in spionid polychaetes, a common deposit-feeding invertebrate. These worms are widely distributed in soft-sediment benthic marine environments and, along with other deposit-feeders, are responsible for the bioturbation that is important to this environment. Some evidence indicates that chemoreception may coordinate sediment ingestion rate and other aspects of deposit-feeding in a variety of species. The proposed research will attempt to identify some of the physiological and molecular mechanisms used by the worms …

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 …

Collaborative Research: Nitrate Flux Associated With Vertically Migrating Phytoplankton In The Central North Pacific, Cynthia H. Pilskaln

University of Maine Office of Research Administration: Grant Reports

This proposal will address a fundamental problem in biological oceanography format he viewpoint that vertically migrating algal mats in the open ocean are instrumental in redistributing nitrogen within the surface waters of the North Pacific Ocean. Using previously funded shiptime, the project will documents Rhizosolenia mat vertical distribution throughout the upper 100-300 m, the quantitative N inputs, and potential for NO₃-release in the surface layers by mats in the central North Pacific gyre. The research will characterize depth of origin, migration times and absolute transport rates by these macroscopic associations and determine if NO₃-release by mat …