Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

Theses/Dissertations

2003

Oceanography and Atmospheric Sciences and Meteorology

Articles 1 - 30 of 65

Full-Text Articles in Physical Sciences and Mathematics

Analysis Of The Spatial Dynamics Of The American Lobster (Homarus Americanus) Fishery Along The Coast Of Maine, Kevin M. Scheirer Dec 2003

Analysis Of The Spatial Dynamics Of The American Lobster (Homarus Americanus) Fishery Along The Coast Of Maine, Kevin M. Scheirer

Electronic Theses and Dissertations

The American lobster (Homarus americanus) supports the most valuable commercial fishery in the northeastern United States, thus the fishery is critical to Maine's economy. No systematic study has been done to collect information about, identify, and quantify the spatial dynamics of the Maine lobster fishery. This project helps to provide a better understanding of Maine's lobster fishery dynamics, and it will aid f'iture efforts to improve the stock assessment of Maine's lobster fishery. The analysis consists of three distinct parts: (1) comparison of data collected by two separate fishery dependent sampling programs; (2) spatial analysis of electronic logbook data; and …


Specific Dynamic Action, Growth And Development In Larval Atlantic Cod, Gadus Morhua, Jessica A. Geubtner Dec 2003

Specific Dynamic Action, Growth And Development In Larval Atlantic Cod, Gadus Morhua, Jessica A. Geubtner

Electronic Theses and Dissertations

The larval stage of marine fish is a period of rapid growth and development. Atlantic cod (Gadus morhua) are approximately 4-5 rnm in length upon hatch and feed endogenously from their yolk sac for the first week. After this time, larval cod must successfully capture live prey to survive and to fuel high growth rates of greater than 10%d". Previous studies have found that during exogenous feeding and at growth rates greater than 8%d1 larvae experience what appears to be cost free growth, where mass specific metabolic rate does not decrease with increasing mass. Due to size and condition constraints …


Pond-Breeding Amphibian Species Distributions In A Beaver-Modified Landscape, Acadia National Park, Mount Desert Island, Maine, Jesse Cunningham Dec 2003

Pond-Breeding Amphibian Species Distributions In A Beaver-Modified Landscape, Acadia National Park, Mount Desert Island, Maine, Jesse Cunningham

Electronic Theses and Dissertations

In order to maintain pond-breeding amphibian species richness, it is important to understand how both natural and anthropogenic disturbances affect species assemblages and individual species distributions both at the scale of individual ponds and at a larger landscape scale. The goal of this project was to investigate what characteristics of ponds and the surrounding wetland landscape were most effective in predicting pond-breeding species richness and the individual occurrence of wood frog (Rana sylvatica), bullfrog (Rana catesbeiana) and pickerel frog (Rana palustris) breeding sites in a beaver-modified landscape and how this landscape has changed over …


The Role Of Larval Thermal Tolerance In The Distribution Of Blue Mussel Species Within The Gulf Of Maine, Susan J. Limbeck Dec 2003

The Role Of Larval Thermal Tolerance In The Distribution Of Blue Mussel Species Within The Gulf Of Maine, Susan J. Limbeck

Electronic Theses and Dissertations

Two species of blue mussel, Myrilus edulis and Myrilus trossulus, are sympatric throughout much of the Canadian Maritime Provinces and into the Gulf of Maine. While the distribution of M edulis extends south to the Mid-Atlantic, that of M. trossulus ends abruptly in the Gulf of Maine. I have hypothesized that these differences in adult distribution are the result of species-specific variation in larval thermal tolerances. Previously, it has been shown that when reared at 20 OC, from 36 hour post-fertilization through settlement, M. trossulus had significantly higher mortality rates than M. edulis. This study examined whether species-specific differences in …


An Investigation Of The Cumulative Impacts Of Shrimp Trawling On Mud Bottom Fishing Grounds In The Gulf Of Maine: Effects On Habitat And Macrofaunal Community Structure, Anne W. Simpson Dec 2003

An Investigation Of The Cumulative Impacts Of Shrimp Trawling On Mud Bottom Fishing Grounds In The Gulf Of Maine: Effects On Habitat And Macrofaunal Community Structure, Anne W. Simpson

Electronic Theses and Dissertations

Despite the widespread occurrence of trawl fisheries on mud-bottoms, there is limited knowledge concerning the effects of trawling induced disturbance on these habitats and their resident macrofaunal communities. I investigated the cumulative impacts of seasonal commercial shrimp trawling on infaunal habitat and macrofaunal community structure on two mud-bottom fishing grounds in the Gulf of Maine from June 2000 - December 2001. One fishing ground located near the Outer Pumpkin Ledges (Pumpkin) experienced trawling activity during the 2000-2001 fishing season. In contrast, the other fishing ground near Monhegan Island was not trawled during the same period because shrimp abundances were low. …


A Comparison Of The Ecological Integrity Of Headwater Streams Draining Harvested And Un-Harvested Watersheds In The Western Mountains Of Maine, U.S.A., Darlene Siegel Dec 2003

A Comparison Of The Ecological Integrity Of Headwater Streams Draining Harvested And Un-Harvested Watersheds In The Western Mountains Of Maine, U.S.A., Darlene Siegel

Electronic Theses and Dissertations

Physical, chemical, and biological characteristics of four headwater streams draining forested watersheds were compared to determine the effectiveness of Riparian Management Zones (RMZs) in protecting aquatic ecological integrity from the effects of forest harvesting. Two of the watersheds were harvested with a 30% sheltenvood cut and a 75 foot buffer was left adjacent to the streams. The other two watersheds were un-harvested and were used as reference conditions for comparison with the harvested watersheds. General environmental conditions in these four headwater streams during the study period were characterized as follows. Each stream was located within a mixed- wood forest dominated …


Age, Growth And The Annual Cycles Of Lipogenesis And Reproduction Of Acanthurus Bahianus In Southeastern Florida, Stacy M. Wolfe Dec 2003

Age, Growth And The Annual Cycles Of Lipogenesis And Reproduction Of Acanthurus Bahianus In Southeastern Florida, Stacy M. Wolfe

HCNSO Student Theses and Dissertations

The ocean surgeon, Acanthurus bahianus, is a coral reef fish inhabiting the tropical and subtropical waters of the western Atlantic, including southeastern Florida. This study was a 23-month analysis of the reproductive cycle correlated with the annual build up and depletion of fat reserves in the fish. In addition, an age and growth analysis of this species was conducted. A total of 507 fish were analyzed for length, weight, gonad weight and fat body weight. 478 were aged by microscopic examination of the transverse section of the sagittae otolith. The von Bertalannfy growth equation was used to determine length at …


Wind-Induced Exchange In Semi-Enclosed Basins, Rosario Sanay Oct 2003

Wind-Induced Exchange In Semi-Enclosed Basins, Rosario Sanay

OES Theses and Dissertations

The wind-induced circulation over laterally varying bathymetry was investigated in homogeneous and in stratified systems using the three-dimensional Regional Ocean Model (ROMS). For homogeneous systems, the focus was to describe the influence of the earth's rotation on the lateral distribution of the flow with particular emphasis on the transverse circulation. Along-basin wind-stress with no rotation caused a circulation dominated by an axially symmetric transverse structure consisting of downwind flow over the shoals and upwind flow in the channel along the whole domain. Transverse circulation was important only at the head of the system where the water sank and reversed direction …


A Full-Wave Investigation Of The Use Of A 'Cancellation Factor' In Gw-Airglow Interaction Studies, Yonghui Yu Sep 2003

A Full-Wave Investigation Of The Use Of A 'Cancellation Factor' In Gw-Airglow Interaction Studies, Yonghui Yu

Master's Theses - Daytona Beach

Atmospheric gravity waves (GWs) perturb minor species involved in the chemical reactions of airglow emissions in the mesopause region of the earth's atmosphere. The so-called 'Cancellation Factor' (CF) is defined as a transfer function relating the amplitude of airglow brightness fluctuation to the amplitude of GW-induced fluctuation in temperature [Swenson and Gardner, 1998]. This transfer factor can be used to determine GW fluxes and the forcing effects of GWs on the mean state through airglow observations, because GW fluxes are proportional to the square of GW amplitude.

Numerical models [Walterscheid et al., 1987; Schubert et al., 1991] have previously shown …


Effects Of Nitrogen Deposition And Flow Permanence On Stream Organic Matter Dynamics, Michael Andrew Joseph Chadwick Aug 2003

Effects Of Nitrogen Deposition And Flow Permanence On Stream Organic Matter Dynamics, Michael Andrew Joseph Chadwick

Electronic Theses and Dissertations

The objective of this study was to investigate the effects of N enrichment and flow permanence on stream organic matter dynamics at the Bear Brook Watershed in Maine (BBWM). BBWM is a paired-catchment manipulation of atmospheric (NH4)2SO4 deposition, and the goal of the experiment is to understand how increased N affects forested catchments. The treatment has increased stream nitrate and foliar N concentrations in the treatment watershed. Because streams draining BBWM are intermittent, this investigation provided an opportunity to investigate the combined effects of stream flow permanence and human alteration of N cycling in a …


Resilience Of Green Sea Urchin (Strongylocentrotus Droebachiensis) Populations Following Fishing Mortality: Marine Protected Areas, Alternate Stable States, And Larval Ecology, John Vavrinec Iii Aug 2003

Resilience Of Green Sea Urchin (Strongylocentrotus Droebachiensis) Populations Following Fishing Mortality: Marine Protected Areas, Alternate Stable States, And Larval Ecology, John Vavrinec Iii

Electronic Theses and Dissertations

The green sea urchin Strongylocentrotus droebachiensis has been aggressively fished in Maine since 1986 resulting in severe population declines throughout portions of the state. This research used Marine Protected Areas (MPAs) to evaluate the potential for recovery in depleted sea urchin populations. It was necessary to not only look at the direct impacts of the MPAs, but also at larval transport / supply and community interactions to gain a better understanding of the system. We found that MPAs in the Gulf of ~a!ne were of varied utility to restoring depleted sea urchin populations depending on location and community structure. MPAs …


Travel Time Study At The Wetlands Park National Preserve, Brandon Bair May 2003

Travel Time Study At The Wetlands Park National Preserve, Brandon Bair

UNLV Theses, Dissertations, Professional Papers, and Capstones

This thesis reports on a study of the residence time of water in the Wetlands Park Nature Preserve in Henderson, Nevada. Rhodamine WT was used in order to test for the travel time of the water from the Monson Channel inflow to the Nature Preserve outflow to the Las Vegas Wash. The initial hypothesis was that the water would stay in the system for approximately 8 days. Residence time was tested using an ISCO sampling machine along with a Sequoia-Turner model 450 fluorimeter to test for the fluoresce of the dye in the water. All samples collected were taken immediately …


Fluctuations In Chinook Salmon (Oncorhynchus Tshawytscha) Counts At Three Lower Columbia River Spawning Sites, Eric Michael Loomis May 2003

Fluctuations In Chinook Salmon (Oncorhynchus Tshawytscha) Counts At Three Lower Columbia River Spawning Sites, Eric Michael Loomis

UNLV Theses, Dissertations, Professional Papers, and Capstones

Several hypotheses were developed to explore the pronounced increase in Chinook salmon (Oncorhynchus tshawytscha) returning to spawning grounds at the Cowlitz, Kalama, and Lewis Rivers, three tributaries of the lower Columbia River. The study was conducted using data compiled over a ten-year span from 1991-2001. Preliminary indications are that trends in climate are linked to these increases, with the absence of El Niño events and fluctuations in winter precipitation as likely explanations of these phenomena. The unique nature of Chinook life cycles causes them to utilize a variety of habitats that require ideal conditions for maximum survival rates. Correlations between …


The Use Of Acoustics To Resolve Nightly Excursions Of Hyperbenthos, Heather U. Abello May 2003

The Use Of Acoustics To Resolve Nightly Excursions Of Hyperbenthos, Heather U. Abello

Electronic Theses and Dissertations

Acoustic analysis of die1 vertical migration in the Darnariscotta River estuary, Maine, showed a fairly regular nightly increase in biovolume (mm3 m'3) of organisms in the water column, presumed to be due to emergence, the entry of hyperbenthic organisms into the water column. Timing of these events was significantly correlated with time of sunset and time of sunrise for more than 50% of the dates where emergence and re-entry could be identified, between June and October 2002. Emergence traps indicate that the mysid shrimp, Neomysis americana, is the predominant migrator. Daily fluctuations in irradiance influence the timing of emergence fiom …


Modeling Bird Species Occurrence In Current And Future Landscapes, Stephen Nicholas Matthews May 2003

Modeling Bird Species Occurrence In Current And Future Landscapes, Stephen Nicholas Matthews

Electronic Theses and Dissertations

With mounting evidence that global temperatures have increased significantly over the last century and the projections of greater changes in climate by the end of this century, understanding the potential consequences of these changes for species is essential to conservation efforts. Here I evaluate the potential response of birds to projected climate change by using regression tree analysis to create models of species distributions under current conditions from Breeding Bird Survey data and then project these models onto General Circulation Model (GCM) scenarios of global climate change. Before modeling species responses to climate change, I selected seventeen bird species to …


Scope For Activity, Specific Dynamic Action And Growth In Early Juvenile Stages Of Atlantic Cod, Gadus Morhua, Sorren Lund Hansen May 2003

Scope For Activity, Specific Dynamic Action And Growth In Early Juvenile Stages Of Atlantic Cod, Gadus Morhua, Sorren Lund Hansen

Electronic Theses and Dissertations

Growth rates of early life stages of Atlantic cod (Gadus morhua) are very high, but decline, as the fish grow larger. Little is know about the physiological processes that facilitate and regulate this growth pattern. In this study, feeding and swimming metabolism were measured in individual juvenile Atlantic cod (Gadus morhua) in order to investigate how energy are allocated to swimming and growth in fast growing stages of fishes. Metabolic rates were measured by the means of oxygen consumption using two "Brett-type" respirometers. The metabolic measurements were repeated several times in individual juvenile Atlantic cod with a wet body mass …


Lipid Solubilization By Marine Benthic Invertebrates, Ian M. Voparil May 2003

Lipid Solubilization By Marine Benthic Invertebrates, Ian M. Voparil

Electronic Theses and Dissertations

This work characterized the size of lipoidal colloids in benthic invertebrates' guts, using contact angle dilutions and imaging the fluorescence of the hydrophobic probe Nile Red. Deposit feeders and Nereis virens ingesting sediment were found to have micelles rather than emulsions in the gut. Gut fluids from Arenicola manna (a deposit-feeding polychaete) readily formed emulsions when incubated with mussel meat (Mytilus edulis; 80 g-mussel L"-gut fluid), suggesting that micelles form due to a paucity of emulsifying lipids in the gut. Lipid tracer contained in emulsion droplets was twice as likely to be captured by sediment than was tracer in micelles. …


Population Dynamics And Spatial Analysis Of The Maine Green Sea Urchin (Strongylocentrotus Droebachiensis) Fishery, Robert C. Grabowski May 2003

Population Dynamics And Spatial Analysis Of The Maine Green Sea Urchin (Strongylocentrotus Droebachiensis) Fishery, Robert C. Grabowski

Electronic Theses and Dissertations

Fisheries research on the green sea urchin in Maine has been limited despite its importance to the state's fishing industry. The objective of this thesis was to generate critical information for the management and monitoring of the Maine green sea urchin fishery. In particular there are three main areas of interest: (1) an investigation of biological reference points; (2) spatial analysis and biomass estimation, and (3) the development of a simulation framework approach to determine an optimal sampling strategy for the fishery-independent survey program. Biological reference points are markers conlrnonly used to monitor and manage fisheries. For the Maine sea …


Tidal Modulation Of Nocturnal Vertical Migration From The Benthos: A High-Resolution Acoustic Analysis, Leslie E. Taylor May 2003

Tidal Modulation Of Nocturnal Vertical Migration From The Benthos: A High-Resolution Acoustic Analysis, Leslie E. Taylor

Electronic Theses and Dissertations

Emergence-trap sampling has shown that several species living primarily on or in the sediment emerge nightly into the water column. This behavior was investigated using acoustic and traditional sampling methods. A TRACOR acoustic profiler, TAPS, was mounted on the sea bottom, looking upwards in approximately 10 m of water in the Damariscotta River estuary, Walpole, Maine. TAPS emits high-frequency (265-3000 kHz) sonar pulses and each minute measures backscatter from 12.5-cm range bins in the water column. TAPS data showed a distinct increase in backscatter in the water column most evenings, beginning around or after dusk and terminating before dawn. The …


Measurement Of Proton Transfer Reaction Rates In A Microwave Cavity Discharge Flowing Afterglow, George M. Brooke Iv Apr 2003

Measurement Of Proton Transfer Reaction Rates In A Microwave Cavity Discharge Flowing Afterglow, George M. Brooke Iv

Physics Theses & Dissertations

The reaction rate coefficients between the hydronium ion and the molecules ethene (C2H4), propene (C3H6), 1-butene (C4H8) and hydrogen sulfide (H2S) were measured at 296 K. The measured reaction rates were compared to collision rates calculated using average dipole orientation (ADO) theory. Reaction efficiency depends primarily upon the proton affinity of the molecules. All the measurements were obtained using the newly developed microwave cavity discharge flowing afterglow (MCD-FA) apparatus. This device uses an Asmussen-type microwave cavity discharge ion source that is …


Evaluation Of The Mountain Wave Forecast Model's Stratospheric Turbulence Simulations, Mark S. Allen Mar 2003

Evaluation Of The Mountain Wave Forecast Model's Stratospheric Turbulence Simulations, Mark S. Allen

Theses and Dissertations

Stratospheric turbulence (Stratoturb) is a well-known hazard to aircraft in flight. Forecasting mountain waves, specifically the breaking of these waves, is necessary to accurately predict the presence of Stratoturb. The Air Force Weather Agency (AFWA) requested a product with the capability of forecasting Stratoturb at 30, 50, and 70 mb using model data currently available, To facilitate their request, the Mountain Wave Forecast Model (MWFM) was acquired from the Naval Research Laboratory. MWFM turbulence forecasts generated twice daily over East Asia, using the AVN and MM5 models for initialization, were compared to S' layer turbulence analyses from the Rawinsonde Observation …


Biology And Ecologyof Epigean Crayfish That Inhabit Everglades Environments Procambarus Alleni (Faxon) And Procambarus Fallax (Hagen), Peggy G. Vanarman Mar 2003

Biology And Ecologyof Epigean Crayfish That Inhabit Everglades Environments Procambarus Alleni (Faxon) And Procambarus Fallax (Hagen), Peggy G. Vanarman

HCNSO Student Theses and Dissertations

Two species of epigean crayfish, Procambarus alleni (the Everglades crayfish) and Procambarus fallax (slough crayfish), may be keystone species that inhabit wetlands in south Florida and the Everglades. Recent field studies showed that although these two species occur in sympatric and syntopic distribution, Everglades crayfish prefer shallow water and short hydroperiod conditions, whereas slough crayfish prefer areas that are more permanently flooded (Hendrix 2000). Slough crayfish have invaded some areas within the range occupied by Everglades crayfish, and may be the more successful competitor. Because of their critical role throughout the trophic structure of Everglades wetlands, shifts in relative abundance …


Data Mining Atmospheric/Oceanic Parameters In The Design Of A Long-Range Nephelometric Forecast Tool, Richard F. Benz Mar 2003

Data Mining Atmospheric/Oceanic Parameters In The Design Of A Long-Range Nephelometric Forecast Tool, Richard F. Benz

Theses and Dissertations

The Department of Defense calls for long-range forecasts to aid in the planning of operations. The goal of this research was to explore the feasibility of predicting, one month in advance, the total monthly cloud cover over the country of Afghanistan. In an attempt to reach this goal, the following objectives were achieved: (1) climatological synoptic study of Afghanistan; (2) survey of Real Time Nephanalysis, outgoing longwave radiation (OLR), and surface observational data; (3) examination of teleconnection indices and sea surface temperatures; (4) standard statistical analysis for prediction; and (5) classification tree analysis (CART), In addition, due to current world …


Comparison Of The Refractive Index Structure Constant Derived From Numerical Weather Prediction (Nwp) Models And Thermosonde Data, De Leon C. Narcisse Mar 2003

Comparison Of The Refractive Index Structure Constant Derived From Numerical Weather Prediction (Nwp) Models And Thermosonde Data, De Leon C. Narcisse

Theses and Dissertations

An accurate depiction of atmospheric turbulence is required for successful employment of a viable airborne laser for the Department of Defense (DOD). The ABL Special Program Office (SEC) which is tasked by the Missile Defense Agency (MDA) bas not designated any particular numerical weather model that is tasked exclusively to model optical turbulence This research compares CLEAR1, 2 X CLEAR I and thermosonde derived values of the refractive index structure constant to optical turbulence values derived from several numerical weather prediction models currently in use by the DOD. The models used were the fifth Generation Mesoscale Model (MM5), the Coupled …


Forecasting Excessive Rainfall And Low-Cloud Bases East Of The Northern Andes And Mesoscale Convective Complex Movement In Central South America, Marc R. Gasbarro Mar 2003

Forecasting Excessive Rainfall And Low-Cloud Bases East Of The Northern Andes And Mesoscale Convective Complex Movement In Central South America, Marc R. Gasbarro

Theses and Dissertations

This research produces better forecast tools for SOUTHCOM's 25th Operational Weather Squadron (OWS) over multiple areas of operation in South America. Heavy rainfall and low-cloud base events along the northeastern Andes foothills are examined, as well as, mesoscale convective complexes (MCCs) in Central South America (CSA). Low clouds, fog, and flooding rains hamper daily Department of Defense (DoD) counter-drug operations in Northwestern South America (NWSA). In addition, fierce MCCs interfere with joint-military exercises in CSA.


Habitat Utilization By Bottlenose Dolphins (Tursiops Truncatus) In Biscayne Bay, Florida, Christine A. Hudak Feb 2003

Habitat Utilization By Bottlenose Dolphins (Tursiops Truncatus) In Biscayne Bay, Florida, Christine A. Hudak

HCNSO Student Theses and Dissertations

Bottlenose dolphins (Tursiops truncatus) exhibit variable distribution patterns, depending upon their geographic location. Habitat utilization patterns in Biscayne Bay, Florida, were examined using the Biscayne Bay Bottlenose Dolphin Photo-ID database obtained from the National Oceanic and Atmospheric Administration (NOAA) Southeast Fisheries Science Center (SEFSC) Miami Laboratory. Habitat coverages in Biscayne Bay were obtained from the Atlas of Marine Resources Version 1.3B CD and the Biscayne Bay National Park CD. Dolphin sightings were overlaid on the habitat coverages using GIS Arcview software.

The effects of habitat, season, behavior, zone (sectioned area of Biscayne Bay), and depth on patterns …


Comparison Of Mussel-Bed Faunas At Blake Ridge And Florida Escarpment Seeps, Kathleen Elizabeth Knick Jan 2003

Comparison Of Mussel-Bed Faunas At Blake Ridge And Florida Escarpment Seeps, Kathleen Elizabeth Knick

Dissertations, Theses, and Masters Projects

No abstract provided.


Taxonomic Composition And Growth Rates Of Phytoplankton Assemblages At The Subtropical Convergence East Of New Zealand, Liza M. Delizo Jan 2003

Taxonomic Composition And Growth Rates Of Phytoplankton Assemblages At The Subtropical Convergence East Of New Zealand, Liza M. Delizo

Dissertations, Theses, and Masters Projects

No abstract provided.


Socioeconomic Effects Of Area Management And The Potential For Community-Based Co-Management: A Case Study Of The Atlantic Sea Scallop Fishery, Winifred L. Ryan Jan 2003

Socioeconomic Effects Of Area Management And The Potential For Community-Based Co-Management: A Case Study Of The Atlantic Sea Scallop Fishery, Winifred L. Ryan

Dissertations, Theses, and Masters Projects

Community concerns regarding natural resource management may be addressed in several forms. The community may participate as part of the public in the management process; community concerns may be included in social impact assessment; and communities may directly participate as managers of resources whether on their own or in conjunction with higher levels of government. In fisheries, typically community concerns are addressed through social impact assessment which is perceived to be lacking in social theory, history, and often effect (Boggs 1994, Little and Krannich 1989). More recent activity and newer regulations show success with co-management, a management regime of shared …


Abundance Trends And Environmental Habitat Usage Patterns Of Bottlenose Dolphins (Tursiops Truncatus) In Lower Barataria And Caminada Bays, Louisiana, Cara Edina Miller Jan 2003

Abundance Trends And Environmental Habitat Usage Patterns Of Bottlenose Dolphins (Tursiops Truncatus) In Lower Barataria And Caminada Bays, Louisiana, Cara Edina Miller

LSU Doctoral Dissertations

The paucity of research into the environmental requirements, stock membership, abundance and residency patterns of bottlenose dolphins (Tursiops truncatus) in coastal Louisiana creates difficulty in understanding how local ecosystems and threats (such as fishery interactions, habitat degradation and pollution) affect populations. This study combined fine-scale environmental measurements and photo-identification techniques to describe patterns of habitat usage and abundance of bottlenose dolphins in lower Barataria Basin from June 1999 to May 2002. In addition I investigated the validity and limitations of using mark-recapture models to estimate abundance from cetacean photo-identification data. Bottlenose dolphins were present year-round in a wide range of …