Oceanography Commons^™

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 …

Diel And Tidal Rhythms Of Emercenge Events Based On Acousitc Observations In A Shallow Estuary, Mei Sato

Electronic Theses and Dissertations

Field observations of emergence events by epibenthic animals were conducted with two Tracor Acoustic Profiling Systems (TAPS) in the Damariscotta River estuary, Maine, in fall 2005 and summer 2006. Spectral analysis revealed that periodic temporal variability of the acoustic signals was concentrated at four periods. One was the solar day (24 h) and the other three were lunar tidal periods of 25.82 (diurnal or Oi), 12.42 (semidiurnal or M2) and 6.21 h (half the semidiurnal period). The mysid Neomysis americana showed strong nocturnal migration patterns of water-column activity during its peak summer emergence season, regulated by the diel cycle. Toward …

Determining Environmental Drivers Of Fish Community Structure Along The Coast Of Maine, Adrian Jordaan

Electronic Theses and Dissertations

The work presented here was conceived to determine whether structure in marine communities could be related to multiple scaled environmental parameters, as seen in lake and stream systems. Four datasets collected from 2001 to 2005 were used. The datasets ranged from local scale tidepool and estuarine surveys, to more regional intertidal/subtidal surveys and conclude using a coast-wide trawl survey. Initially, a bootstrap program for running principal component analysis (PCA) was developed and tested for utility with additional information from Pearson correlation coefficients. The bootstrap-PC A program was capable of determining confidence limits for correlations amongst species. The results from analysis …

Modeling Large Whale Entanglement Injuries: An Experimental Analysis Of The Influence Of Tissue Compliance, Line Tension, And Draw-Length On Epidermal Abrasion Resistance, Jeremy Paul Winn

Electronic Theses and Dissertations

Two test systems were developed to evaluate the influence of draw-length and tissue compliance on entanglement-induced epidermal abrasion in humpback (Megaptera novaeangliae) and right whale (Eubalaena glacialis) tissue samples. Under straight pull abrasion tests an adult right whale fluke required 3.7 times the load and 15 times the draw-length of a right whale calf flipper to induce epidermal failure while a humpback fluke was intermediate between these extremes. Epidermal thickness did not appear to be the cause of this difference in abrasion resistance. Epidermal thickness averaged 8.0k0.2 mm for the calf flipper, 4.9k0.4 rnrn for the humpback fluke, and 5.1k0.1 …

Collaborative Research: Globec-01: Tidal Front Mixing And Exchange On Georges Bank: Controls On The Production Of Phytoplankton, Zooplankton, And Larval Fishes, David W. Townsend, Robert Houghton

University of Maine Office of Research Administration: Grant Reports

Georges Bank supports a rich fishery because: (1) large portions of the bank are shallow enough that light-limitation of phytoplankton is usually not important; (2) deep waters rich in inorganic nutrients are available for mixing onto the bank; and (3) the Bank's clockwise circulation can retain the planktonic stages of important fish species. The tidally mixed front (TMF) is central to the productivity of Georges Bank through the processes of nutrient injection in the north and retention of larvae on the south flank. These two regions are connected by a circulation pathway along the front in which nutrients lead to …

Hydrodynamic Regulation Of Reproduction In Fucoid Algae: A Regional Model And Consequences For Population Structure, Susan H. Brawley

University of Maine Office of Research Administration: Grant Reports

Fucoid algae dominate most rocky shores across the north Atlantic and contribute substantially to structuring of the coastal ecosystem. Reproduction in fucoid algae is sensitive to hydrodynamic conditions, resulting in high fertilization success because gamete release occurs only under calm conditions. These findings have important implications for asynchrony in gamete release between populations and the scale of population isolation. This study will 1) test a nascent model describing when successful fucoid reproduction can occur, 2) determine whether hybridization between Fucus vesiculosus and other fucoid algae occurs when gamete release is delayed by turbulent conditions, and 3) analyze whether genetic differentiation …

Collaborative Research: Functional And Genomic Analysis Of Polysymbiosis In The Wood-Boring Bivalve Lyrodus Pedicellatus, Daniel L. Distel

University of Maine Office of Research Administration: Grant Reports

Each day massive quantities of wood and woody plant materials enter the oceans, providing resources upon which a large variety of marine organisms depend. However, the biological communities supported by marine wood are only poorly understood. Globally, the most important consumers of marine wood are wood-boring bivalves of the family Teredinidae (shipworms, primarily found above 150 m) and Pholadidae (subfamily Xylophagainae, primarily found in the deep sea, 150-8000 m). These clams depend on intracellular endosymbiotic bacteria (endocytobionts) to help them consume a substrate (lignocellulose) that cannot be utilized by most other animals. Two functions have been proposed for symbionts of …

Vascular Morphometry Of The Retina In Antarctic Fishes Is Dependent Upon The Level Of Hemoglobin In Circulation, Jody M. Wujcik

Electronic Theses and Dissertations

Antarctic notothenioids express the circulating oxygen-binding protein hemoglobin (Hb) over a broad range of blood concentrations. White-blooded icefishes (Suborder: Notothenioidei, Family: Channichthyidae) are the only known adult vertebrates to lack Hb completely. In addition to its role in oxygen transport, Hb is the primary reactant in degradation of nitric oxide (NO). Thus, NO should be degraded at a slower rate in Hb-lacking icefishes than in Hb-expressing notothenioids, leading to higher steady-state levels of NO in the former group. Increased levels of NO should stimulate upregulation of angiogenesis, the growth and proliferation of new blood vessels from existing vasculature. Based upon …