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Food Substrates And Digestive Capabilitites Of Marine Deposit Feeders, Lawrence M. Mayer Jul 2002

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 Jul 2002

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 Mar 2002

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 …


Remote Sensing Of The Ne Pacific: Retrospective And Concurrent Time Series Analysis Using Multiple Sensors On Multiple Scales, Andrew C. Thomas Mar 2002

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 …