DOCSLIB.ORG

Bottlenose Dolphin (Tursiops Truncatus) Stock Structure Within the Estuaries of Southern Georgia

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Bottlenose Dolphin (Tursiops Truncatus) Stock Structure Within the Estuaries of Southern Georgia BOTTLENOSE DOLPHIN (TURSIOPS TRUNCATUS) STOCK STRUCTURE WITHIN THE ESTUARIES OF SOUTHERN GEORGIA Brian C. Balmer A Dissertation Submitted to the University of North Carolina Wilmington in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy Department of Biology and Marine Biology University of North Carolina Wilmington 2011 Approved by Advisory Committee Randall Wells Lori Schwacke a Douglas Nowacek Frederick Scharf a Amanda Southwood Williard Andrew Westgate a D. Ann Pabst a Chair Accepted by __________________________ Dean, Graduate School TABLE OF CONTENTS INTRODUCTION..............…………………………………………………………….. iv ACKNOWLEDGEMENTS …………………………………………………………… xiv DEDICATION …………………………………………………………………………xvii LIST OF TABLES …………………………………………………………………… xviii LIST OF FIGURES …………………………………………………………………... xix CHAPTER ONE: RELATIONSHIP BETWEEN PERSISTENT ORGANIC POLLUTANTS (POPS) AND RANGING PATTERNS IN COMMON BOTTLENOSE DOLPHINS (TURSIOPS TRUNCATUS) FROM COASTAL GEORGIA, USA……………………………………………………………………….... 1 ABSTRACT……..…………………………………………………………. 2 INTRODUCTION …………………………………………...................... 4 METHODS ………………………………………………………………... 8 RESULTS ……………………………………………………………….. 16 DISCUSSION …………………………………………………………… 19 CHAPTER TWO: SEASONAL ABUNDANCE, SITE-FIDELITY, HABITAT USE, AND RANGING PATTERNS OF BOTTLENOSE DOLPHINS (TURSIOPS TRUNCATUS) WITHIN THE ESTUARIES OF SOUTHERN GEORGIA, USA…………………………………....................................................................... 29 ABSTRACT……..……………………………………………………….. 30 INTRODUCTION ………………………………………….................... 32 METHODS ………………………………………………………………. 37 RESULTS ……………………………………………………………….. 48 DISCUSSION …………………………………………………………… 68 CHAPTER THREE: DEFINING RESIDENCY PATTERNS FOR COMMON BOTTLENOSE DOLPHINS (TURSIOPS TRUNCATUS) WITHIN THE ESTUARIES OF SOUTHERN GEORGIA, USA…………………………………… 80 ii ABSTRACT……..……………………………………………………….. 81 INTRODUCTION ………………………………………….................... 83 METHODS ………………………………………………………………. 89 RESULTS ………………………………………………………………. 92 DISCUSSION …………………………………………………………… 99 CHAPTER FOUR: EVALUATION OF A SINGLE-PIN, SATELLITE-LINKED TRANSMITTER DEPLOYED ON BOTTLENOSE DOLPHINS (TURSIOPS TRUNCATUS) ALONG THE COAST OF GEORGIA, USA…………………….. 105 ABSTRACT……..……………………………………………………… 106 INTRODUCTION ………………………………………….................. 108 METHODS …………………………………………………………….. 111 RESULTS ……………………………………………………………… 117 DISCUSSION …………………………………………………………. 121 LITERATURE CITED.........…………………………………………………………. 123 iii INTRODUCTION Rationale Bottlenose dolphins (Tursiops truncatus) are top-level predators and long- lived residents within the estuaries of the southeastern United States (reviewed in Shane et al., 1986; Wells and Scott, 1999). Lipophilic persistent organic pollutants (POPs), which are biomagnified in organisms at higher trophic levels, are stored in dolphins‟ lipid-rich blubber, making the bottlenose dolphin a sensitive indicator for POPs in coastal ecosystems. Extremely high contaminant concentrations of POPs have been measured in bottlenose dolphins sampled in the Turtle/Brunswick River Estuary (TBRE), a region located along the southern coast of Georgia (Pulster et al., 2009). However, little baseline data exist on bottlenose dolphins within this region. This dissertation focuses on bottlenose dolphins that utilize the estuaries of southern Georgia, a region that has been exposed to extremely high levels of anthropogenic contaminants. The goals of this dissertation were to determine dolphin abundance and distribution, habitat utilization patterns, and anthropogenic contaminant burdens to better understand bottlenose dolphin stock structure within a complex salt marsh ecosystem in southern Georgia. I specifically compared these features across two adjacent research sites - the heavily polluted waters within the TBRE surrounding the city of Brunswick, Georgia, defined as the Brunswick field site, and the waters surrounding the Sapelo Island National Estuarine Research Reserve (SINERR), defined as the iv Sapelo field site, which was chosen initially as a reference site for comparison to the Brunswick field site. There are four main tools that have been utilized to study the stock structure of coastal bottlenose dolphins. Photo-identification surveys have been used to identify abundance, distribution, and site-fidelity patterns of different groups of dolphins within a region (e.g. Balmer et al., 2008; Read et al., 2003; Speakman et al., 2010; Urian et al., 2009; Williams et al., 1993; Wilson et al., 1999). Satellite-linked and radio telemetry data have determined ranging patterns of individuals that have distributions outside of the boundaries of photo- identification surveys (e.g. NMFS, unpublished data, Balmer et al., 2008). Genetic studies have provided insight into different groups of dolphins that reside within the estuaries and coastal waters of a region (reviewed in Rosel et al., 2009). Anthropogenic contaminant concentrations have been used to identify different groups of dolphins on a broad (e.g. Hansen et al., 2004) and fine (e.g. Litz et al., 2007) geographic scale. My dissertation focuses on combining three of these tools (photo-identification, telemetry, and contaminants) to enhance our knowledge of dolphin stock structure as well as provide insight into the influence of contaminants on bottlenose dolphins within the estuaries of southern Georgia. My Master‟s thesis investigated the stock structure of bottlenose dolphins within the St. Joseph Bay region of Florida‟s northern Gulf of Mexico coast following three unusual mortality events (UMEs), which resulted in over 300 dolphin deaths (NOAA, 2004). I utilized two of the above mentioned tools, photo- identification and telemetry, to determine seasonal abundance, site-fidelity, and v distribution patterns of dolphins within this region. Although the results of this study provided insight into different groups of dolphins utilizing the St. Joseph Bay region, it is still unclear which dolphins were affected by the UMEs, since research had not been conducted prior to these mortality events. The research for my Ph.D. dissertation provided the opportunity to utilize the tools that I implemented in my Master‟s research, as well as an additional stock structure tool, that of contaminant sampling, and a new telemetry methodology, a prototype, single-pin satellite linked tag. The results from my Ph.D. research provided baseline data on bottlenose dolphins in a region with extremely high levels of anthropogenic, point-source contamination, and insight into the potential effects that these contaminants may be having on dolphins within this region. Currently, there have been no UMEs along the southern coast of Georgia, and hopefully there will not be any in the future. However, extremely high levels of contaminants have been identified as a localized stressor on dolphin communities (Schwacke et al., 2002). Thus, unlike in the St. Joseph Bay region where baseline data were collected following several mortality events, the results from my Ph.D. dissertation will provide resource managers with baseline data prior to any mortalities that may occur along the southern coast of Georgia. These data can be utilized to identify causative factors of mortality and determine which groups of dolphins may have been affected. There are two common themes that will be addressed throughout my Ph.D. dissertation. The first is the ability to identify baseline data (abundance, site-fidelity, habitat use, and ranging patterns) for bottlenose dolphins in a vi complex salt marsh ecosystem, in which the defined geographic boundaries of a survey region may or may not be representative of the distribution pattern(s) of a given dolphin or group of dolphins. The second is utilizing differences in contaminant levels between individuals and groups to provide insight into the effects of these contaminant burdens on dolphins and differentiate between dolphin groups by their respective contaminant loads. My research interests have always been focused on how many individuals can be supported within a particular region (i.e. abundance) and why animals live where they do (i.e. habitat use/distribution). The combination of these two themes within the context of my Ph.D. dissertation research has expanded my interest to include how we measure these parameters when animals‟ distributions do not fit the boundaries of our study design. In addition, how do we identify stressors (i.e. contaminants) that may be influencing these parameters, when the animals we are studying spend the majority of their time underwater and conceal many of the effects associated with these anthropogenic stressors? Dissertation structure This dissertation has four chapters that are formatted as manuscripts to specific targeted journals. The first chapter focuses on characterizing the contaminant exposure of dolphins within the two field sites (Brunswick and Sapelo), and examines contaminant profiles in relation to individual dolphin ranging patterns based upon photo-identification sighting histories. The second chapter identifies baseline stock structure data (abundance, site-fidelity, habitat vii use, and ranging patterns) for both field sites using photo-identification surveys and telemetry data. The third chapter defines and utilizes dolphin residency patterns and variations in habitat use to differentiate between dolphins whose ranging patterns overlap within the estuaries of southern Georgia. The fourth chapter evaluates a new satellite-linked tag attachment design that was tested
Load more

Recommended publications
  • A Practical Handbook for Determining the Ages of Gulf of Mexico And
    A Practical Handbook for Determining the Ages of Gulf of Mexico and Atlantic Coast Fishes THIRD EDITION GSMFC No. 300 NOVEMBER 2020 i Gulf States Marine Fisheries Commission Commissioners and Proxies ALABAMA Senator R.L. “Bret” Allain, II Chris Blankenship, Commissioner State Senator District 21 Alabama Department of Conservation Franklin, Louisiana and Natural Resources John Roussel Montgomery, Alabama Zachary, Louisiana Representative Chris Pringle Mobile, Alabama MISSISSIPPI Chris Nelson Joe Spraggins, Executive Director Bon Secour Fisheries, Inc. Mississippi Department of Marine Bon Secour, Alabama Resources Biloxi, Mississippi FLORIDA Read Hendon Eric Sutton, Executive Director USM/Gulf Coast Research Laboratory Florida Fish and Wildlife Ocean Springs, Mississippi Conservation Commission Tallahassee, Florida TEXAS Representative Jay Trumbull Carter Smith, Executive Director Tallahassee, Florida Texas Parks and Wildlife Department Austin, Texas LOUISIANA Doug Boyd Jack Montoucet, Secretary Boerne, Texas Louisiana Department of Wildlife and Fisheries Baton Rouge, Louisiana GSMFC Staff ASMFC Staff Mr. David M. Donaldson Mr. Bob Beal Executive Director Executive Director Mr. Steven J. VanderKooy Mr. Jeffrey Kipp IJF Program Coordinator Stock Assessment Scientist Ms. Debora McIntyre Dr. Kristen Anstead IJF Staff Assistant Fisheries Scientist ii A Practical Handbook for Determining the Ages of Gulf of Mexico and Atlantic Coast Fishes Third Edition Edited by Steve VanderKooy Jessica Carroll Scott Elzey Jessica Gilmore Jeffrey Kipp Gulf States Marine Fisheries Commission 2404 Government St Ocean Springs, MS 39564 and Atlantic States Marine Fisheries Commission 1050 N. Highland Street Suite 200 A-N Arlington, VA 22201 Publication Number 300 November 2020 A publication of the Gulf States Marine Fisheries Commission pursuant to National Oceanic and Atmospheric Administration Award Number NA15NMF4070076 and NA15NMF4720399.
    [Show full text]
  • Comparative Ecology of the Parasites of the Spot, Leiostomus Xanthurus
    W&M ScholarWorks Dissertations, Theses, and Masters Projects Theses, Dissertations, & Master Projects 1989 Comparative ecology of the parasites of the spot, Leiostomus xanthurus Lacepede, and the Atlantic croaker, Micropogonias undulatus Linnaeus (Sciaenidae), in the Cape Hatteras region Dennis A. Thoney College of William and Mary - Virginia Institute of Marine Science Follow this and additional works at: https://scholarworks.wm.edu/etd Part of the Ecology and Evolutionary Biology Commons, and the Zoology Commons Recommended Citation Thoney, Dennis A., "Comparative ecology of the parasites of the spot, Leiostomus xanthurus Lacepede, and the Atlantic croaker, Micropogonias undulatus Linnaeus (Sciaenidae), in the Cape Hatteras region" (1989). Dissertations, Theses, and Masters Projects. Paper 1539616876. https://dx.doi.org/doi:10.25773/v5-j3p5-0627 This Dissertation is brought to you for free and open access by the Theses, Dissertations, & Master Projects at W&M ScholarWorks. It has been accepted for inclusion in Dissertations, Theses, and Masters Projects by an authorized administrator of W&M ScholarWorks. For more information, please contact [email protected]. INFORMATION TO USERS The most advanced technology has been used to photo­ graph and reproduce this manuscript from the microfilm master. UMI films the text directly from the original or copy submitted. Thus, some thesis and dissertation copies are in typewriter face, while others may be from any type of computer printer. The quality of this reproduction is dependent upon the quality of the copy submitted. Broken or indistinct print, colored or poor quality illustrations and photographs, print bleedthrough, substandard margins, and improper alignment can adversely affect reproduction. In the unlikely event that the author did not send UMI a complete manuscript and there are missing pages, these will be noted.
    [Show full text]
  • Candidate Species for Florida Aquaculture: Atlantic Croaker, Micropogonias Undulatus1
    FA 148 Candidate Species for Florida Aquaculture: Atlantic Croaker, Micropogonias undulatus1 R. LeRoy Creswell, Cortney L. Ohs, and Christian L. Miller2 Atlantic Croaker Geographic Distribution and Habitat The Atlantic croaker is known to occur in the northern and eastern parts of the Gulf of Mexico, along the Atlantic coast of the United States from south Florida to Massachusetts, in the Greater Antilles, and along the South American Atlantic Figure 1. Atlantic Croaker Micropogonias undulatus Credits: Food and Agriculture Organization of the United coast from Surinam to Argentina. Its U.S. fishing Nations 1978 grounds extend from the Rio Grande to Tampa Bay in the Gulf of Mexico and from northern Florida to General Description Cape Hatteras on the Atlantic coast. In Florida, Atlantic croaker are seldom found south of Tampa The Atlantic croaker, Micropogonias undulatus Bay or the Indian River Lagoon on the Atlantic coast (Figure 1), is a member of the family Sciaenidae, the (Lankford and Targett 1994). Croaker are found over drum family. This medium-sized fish is slightly mud and sandy mud bottoms in coastal waters to elongate, moderately compressed, and silvery in color about 1,000 meter depth and in estuaries where the with a pinkish cast; the back and upper sides are nursery and feeding grounds are located. grayish with black spots forming irregular, oblique lines above the lateral line. The dorsal fin has small Natural History black dots and a black edge; other fins are pale to yellowish. The chin has 3 to 5 pairs of barbels along Atlantic croaker are medium-sized members of the inner edge of the lower jaw.
    [Show full text]
  • Drum and Croaker (Family Sciaenidae) Diversity in North Carolina
    Drum and Croaker (Family Sciaenidae) Diversity in North Carolina The waters along and off the coast are where you will find 18 of the 19 species within the Family Sciaenidae (Table 1) known from North Carolina. Until recently, the 19th species and the only truly freshwater species in this family, Freshwater Drum, was found approximately 420 miles WNW from Cape Hatteras in the French Broad River near Hot Springs. Table 1. Species of drums and croakers found in or along the coast of North Carolina. Scientific Name/ Scientific Name/ American Fisheries Society Accepted Common Name American Fisheries Society Accepted Common Name Aplodinotus grunniens – Freshwater Drum Menticirrhus saxatilis – Northern Kingfish Bairdiella chrysoura – Silver Perch Micropogonias undulatus – Atlantic Croaker Cynoscion nebulosus – Spotted Seatrout Pareques acuminatus – High-hat Cynoscion nothus – Silver Seatrout Pareques iwamotoi – Blackbar Drum Cynoscion regalis – Weakfish Pareques umbrosus – Cubbyu Equetus lanceolatus – Jackknife-fish Pogonias cromis – Black Drum Larimus fasciatus – Banded Drum Sciaenops ocellatus – Red Drum Leiostomus xanthurus – Spot Stellifer lanceolatus – Star Drum Menticirrhus americanus – Southern Kingfish Umbrina coroides – Sand Drum Menticirrhus littoralis – Gulf Kingfish With so many species historically so well-known to recreational and commercial fishermen, to lay people, and their availability in seafood markets, it is not surprising that these 19 species are known by many local and vernacular names. Skimming through the ETYFish Project
    [Show full text]
  • Spatial and Temporal Resource Partitioning
    TEXAS J. OF SCI. 64(1):0-00 FEBRUARY, 2012 (PUBLISHED JUNE 2015) HABITAT USE AND DIETS OF JUVENILE SPOT (LEIOSTOMUS XANTHURUS) AND ATLANTIC CROAKER (MICROPOGONIAS UNDULATUS) IN A SMALL ESTUARY AT MAD ISLAND MARSH, TEXAS Senol Akin1, 2 and Kirk O. Winemiller1 1Department of Wildlife and Fisheries Sciences, Texas A&M University, 2258 TAMU College Station, TX 77843-2258 2 Current address: Faculty of Agriculture, Department of Fisheries, Gaziosmanpasa University, 60240, Tokat, Turkey ABSTRACT.–Spatial and temporal variation in feeding of immature stages (10-130 mm standard length) of two sciaenids, spot (Leiostomus xanthurus) and Atlantic croaker (Micropogonias undulatus), was investigated at Mad Island Marsh on the Texas Gulf coast from March 1998 through August 1999. Periods of peak abundance of each species were different (December for croaker, March for spot). The two species were dissimilar in diet and habitat use along the longitudinal gradient of a small estuary, except for the winter months of both years when postlarvae dominated samples and dietary overlap was high. Low dietary overlap occurred despite the fact that both species consumed mostly benthic organisms (amphipods, gastropods, nematodes, polychaetes), pelagic copepods, and detritus. Overall, spot consumed greater proportions of copepods, nematodes and chironomid larvae, and croakers had broader diets that included most of the abundant invertebrates in the habitat (e.g., amphipods, shrimp, blue crabs) plus smaller percentages of fish. Regardless of season and body size, the spot diet was dominated by copepods and nematodes. The croaker had a more pronounced ontogenetic diet shift, with the smallest size classes (10-25 mm) consuming mostly copepods, and larger juveniles having diets dominated by amphipods, polychaete worms, shrimp, crabs, and fish.
    [Show full text]
  • Diet Analysis of Stranded Bottlenose Dolphins (<I>Tursiops Truncatus</I
    Old Dominion University ODU Digital Commons Biological Sciences Theses & Dissertations Biological Sciences Spring 2020 Diet Analysis of Stranded Bottlenose Dolphins (Tursiops truncatus) in Virginia Kristen Marie Volker Old Dominion University, [email protected] Follow this and additional works at: https://digitalcommons.odu.edu/biology_etds Part of the Biology Commons, Ecology and Evolutionary Biology Commons, and the Marine Biology Commons Recommended Citation Volker, Kristen M.. "Diet Analysis of Stranded Bottlenose Dolphins (Tursiops truncatus) in Virginia" (2020). Master of Science (MS), Thesis, Biological Sciences, Old Dominion University, DOI: 10.25777/6bas-rj82 https://digitalcommons.odu.edu/biology_etds/113 This Thesis is brought to you for free and open access by the Biological Sciences at ODU Digital Commons. It has been accepted for inclusion in Biological Sciences Theses & Dissertations by an authorized administrator of ODU Digital Commons. For more information, please contact [email protected]. DIET ANALYSIS OF STRANDED BOTTLENOSE DOLPHINS (TURSIOPS TRUNCATUS) IN VIRGINIA by Kristen Marie Volker B.S. December 2008, University of New England A Thesis Submitted to the Faculty of Old Dominion University in Partial Fulfillment of the Requirements for the Degree of MASTER OF SCIENCE BIOLOGY OLD DOMINION UNIVERSITY MAY 2020 Approved by: Ian Bartol (Director) Holly Gaff (Member) Kent Carpenter (Member) Damon Gannon (Member) ABSTRACT DIET ANALYSIS OF STRANDED BOTTLENOSE DOLPHINS (TURSIOPS TRUNCATUS) IN VIRGINIA Kristen Marie Volker Old Dominion University, 2020 Director: Dr. Ian Bartol This study describes the diet of bottlenose dolphins (Tursiops truncatus) stranded in Virginia via stomach content analysis and considers factors such as proportion of numerical abundance and reconstructed mass, frequency of occurrence, average reconstructed prey size, prey diversity and quantity, and otolith degradation code.
    [Show full text]
  • Atlantic Croaker Micropogonias Undulatus Contributor: J
    Atlantic Croaker Micropogonias undulatus Contributor: J. David Whitaker DESCRIPTION Taxonomy and Basic Description The Atlantic croaker is the only representative of the genus in the western North Atlantic. This species gets its name from the deep By Diane Rome Peebles from the Florida Division of Marine Resources Web Site. croaking sounds created by muscular action on the air bladder. It is one of 23 members of the family Sciaenidae found along the Atlantic and Gulf of Mexico coasts (Mercer 1987). The species has a typical fusiform shape, although it is somewhat vertically compressed. The fish is silvery overall with a faint pinkish-bronze cast. The back and upper sides are grayish, with brassy or brown spots forming wavy lines on the side (Manooch 1988). The gill cover has three to five prominent spines and there are three to five small chin barbels. It has a slightly convex caudal fin. Atlantic croaker south of Cape Hatteras reach maturity after one year at lengths of 140 to 180 mm (5.5 to 7 inches) and are thought to not survive longer than one or two years (Diaz and Onuf 1985). North of Cape Hatteras, the fish matures a year later at lengths greater than 200 mm (8 inches) and individuals may live several years. The Atlantic croaker reaches a maximum length of 500 mm (20 inches) (Hildebrand and Schroeder 1927). Catches of large Atlantic croaker appear to be relatively common on Chesapeake Bay, but large individuals of Atlantic croaker are rare in South Carolina. Bearden (1964) speculated that small croaker from South Carolina may migrate north, but limited tagging studies could not corroborate that assertion.
    [Show full text]
  • Atlantic Croaker
    CHAPTER 2: ATLANTIC CROAKER Populated with Habitat Section from Amendment I to the ISFMP (ASMFC 2005) Section I. General Description of Habitat Atlantic croaker was described by Petrik et al. (1999) as a habitat generalist. Field surveys of post- settlement croaker in estuarine nursery areas found no significant differences in abundances among SAV, marsh edge, and sandy bottom (Petrik et al. 1999). In a wetland system, Atlantic croaker along the Gulf Coast preferred non-vegetated bottom adjacent to wetlands rather than the marsh itself (Rozas and Zimmerman 2000). In North Carolina, Atlantic croaker have been documented to utilize SAV, wetlands, non-vegetated soft bottom, and to a lesser extent, shell bottom (Street et al. 2005). Juvenile croaker use these habitats for refuge and foraging and as a corridor through the estuary. In North Carolina, Atlantic croaker is one of the dominant juvenile fish species in the estuaries (North Carolina Division of Marine Fisheries, unpublished data). Because croaker utilizes multiple habitats, the effect of habitat change and condition on fish population is difficult to assess. Part A. Spawning Habitat Geographic and Temporal Patterns of Migration Atlantic croaker spawn predominantly on the continental shelf, at depths ranging from 7 to 81 m (26 to 266 ft), but also in tidal inlets and estuaries (Diaz and Onuf 1985; Able and Fahay 2010). Atlantic croaker have a long spawning season that generally starts in late summer and continues to early spring, with peak reproductive activity occurring in late fall and winter (Diaz and Onuf 1985). In the Chesapeake Bay and North Carolina, spawning begins as early as August and usually peaks in October, whereas peak spawning occurs in November in the Gulf of Mexico (USFWS 1996).
    [Show full text]
  • Diets of Coastal Bottlenose Dolphins from the U. S. Mid
    MARINE MAMMAL SCIENCE, 20(3):527-545 (July 2004) 0 2004 by the Society for Marine Mammalogy DIETS OF COASTAL BOTTLENOSE DOLPHINS FROM THE U.S. MID-ATLANTIC COAST DIFFER BY HABITAT DAMONP. GANNON' DANIELLEM. WAPLES Duke University Marine Laboratory, Nicholas School of the Environment and Earth Sciences, Duke University, 135 Duke Marine Lab Road, Beaufort, North Carolina 28516, U.S.A. E-mail: [email protected] ABSTRACT We recorded 31 species in the stomachs of 146 coastal bottlenose dolphins (Tursiops truncatu) from North Carolina, U.S.A. Sciaenid fishes were the most common prey (frequency of occurrence = 95%). By mass, Atlantic croaker (Micropogonias undulatus) dominated the diet of dolphins that stranded inside estuaries, whereas weakfish (Cynosicon regalis) was most important for dolphins in the ocean. Inshore squid (Loligo sp.) was eaten commonly by dolphins in the ocean, but not by those in the estuaries. There was no significant pattern in prey size associated with dolphin demography, but the proportion of the diet represented by croaker was higher for males than for females, and mature dolphins ate more croaker than did juveniles. Dietary differences between dolphins that stranded in the estuaries and those that stranded on ocean beaches support the hypothesis that some members of the population inhabit the ocean primarily while others reside principally in estuaries. The overwhelming majority of prey were soniferous species (75% of numerical abundance), which is consistent with the hypothesis that bottlenose dolphins use passive listening to locate noise-making fishes. However, spatiotemporal patterns in consumption of Sciaenid fishes did not coincide with their spawning, which is when peak sound production is thought to occur.
    [Show full text]
  • Life History of Silver Perch Bairdiella Chrysoura (Lacepède, 1803) in North-Central Gulf of Mexico Estuaries Gretchen L
    Gulf of Mexico Science Volume 27 Article 7 Number 1 Number 1 2009 Life History of Silver Perch Bairdiella chrysoura (Lacepède, 1803) in North-Central Gulf of Mexico Estuaries Gretchen L. Grammer Grand Bay National Estuarine Research Reserve Nancy J. Brown-Peterson University of Southern Mississippi Mark S. Peterson University of Southern Mississippi Bruce H. Comyns University of Southern Mississippi DOI: 10.18785/goms.2701.07 Follow this and additional works at: https://aquila.usm.edu/goms Recommended Citation Grammer, G. L., N. J. Brown-Peterson, M. S. Peterson and B. H. Comyns. 2009. Life History of Silver Perch Bairdiella chrysoura (Lacepède, 1803) in North-Central Gulf of Mexico Estuaries. Gulf of Mexico Science 27 (1). Retrieved from https://aquila.usm.edu/goms/vol27/iss1/7 This Article is brought to you for free and open access by The Aquila Digital Community. It has been accepted for inclusion in Gulf of Mexico Science by an authorized editor of The Aquila Digital Community. For more information, please contact [email protected]. Grammer et al.: Life History of Silver Perch Bairdiella chrysoura (Lacepède, 1803 Gulf of Mexico Science, 2009(1), pp. 62–73 Life History of Silver Perch Bairdiella chrysoura (Lacepe`de, 1803) in North-Central Gulf of Mexico Estuaries GRETCHEN L. GRAMMER,NANCY J. BROWN-PETERSON,MARK S. PETERSON, AND BRUCE H. COMYNS Silver perch, Bairdiella chrysoura (Lacepe`de) [n = 485, 70.0–171.0 mm standard length (SL)] were collected from April 2002 through June 2003 in estuaries along the coast of Mississippi to quantify their life history. Ages estimated from sagittal otoliths ranged from 0 to 4 yr.
    [Show full text]
  • Common Bottlenose Dolphin, Tursiops Truncatus, Seasonal Habitat Use and Associations with Habitat Characteristics in Roanoke Sound, North Carolina
    2019, 32 Heather M. Hill Editor Peer-reviewed Common Bottlenose Dolphin, Tursiops truncatus, Seasonal Habitat Use and Associations with Habitat Characteristics in Roanoke Sound, North Carolina Shauna McBride-Kebert1,2, Jessica S. Taylor3, Krystan A. Wilkinson1,4, Heidi Lyn5, Frank R. Moore6, Donald F. Sacco2, Bandana Kar7, and Stan A. Kuczaj II2 1 Chicago Zoological Society’s Sarasota Dolphin Research Program c/o Mote Marine Laboratory, U.S.A. 2 School of Psychology, University of Southern Mississippi, U.S.A. 3 Outer Banks Center for Dolphin Research, U.S.A. 4 School of Natural Resources and Environment, University of Florida, U.S.A. 5 Department of Psychology, University of South Alabama, U.S.A. 6 School of Biological, Environmental, and Earth Sciences, University of Southern Mississippi, U.S.A. 7 National Security Emerging Technologies Division, Oak Ridge National Laboratory, U.S.A. Understanding how habitat characteristics influence common bottlenose dolphin, Tursiops truncatus, distribution and behavior can be useful for conservation. The dolphin community in Roanoke Sound, North Carolina, primarily exhibits seasonal residency, and there is limited information on their habitat use. The objectives of this study were to increase habitat use knowledge and to determine the relationship between habitat characteristics and dolphin distribution using standardized photographic-identification data (2009-2017). A hot spot (Getis-Ord Gi*) analysis showed dolphins frequently use the southern region containing the mouth of the estuary for feeding and traveling. Habitat characteristics were modeled with zero-altered gamma (ZAG), generalized linear (GLM), and generalized additive (GAM) models to predict dolphin group density. Models showed that groups were more likely to be present in areas with greater benthic slope variation and shallow areas closer to land and that different habitat characteristics were associated with feeding, social, and travel activities.
    [Show full text]
  • Converse-Dissertation-2018
    Copyright by Aubrey Koch Converse 2018 The Dissertation Committee for Aubrey Koch Converse Certifies that this is the approved version of the following Dissertation: Functions and signaling mechanisms of the membrane androgen receptor ZIP9 in Atlantic croaker (Micropogonias undulatus) and zebrafish (Danio rerio) ovaries Committee: _____________________________ Peter Thomas, Supervisor _____________________________ Deana Erdner _____________________________ Andrew Esbaugh _____________________________ John Richburg Functions and signaling mechanisms of the membrane androgen receptor ZIP9 in Atlantic croaker (Micropogonias undulatus) and zebrafish (Danio rerio) ovaries by Aubrey Koch Converse Dissertation Presented to the Faculty of the Graduate School of The University of Texas at Austin in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy The University of Texas at Austin December 2018 Dedication I dedicate this work to my father Jeff Koch and daughter Chloe Converse, I love you both with all my heart. Acknowledgements First and foremost, I need to thank my advisor Peter Thomas, who has provided immeasurable support in the completion of this work. My research and writing skills have considerably improved under his guidance. Thank you to my committee, Deana Erdner, Andrew Esbaugh, and John Richburg, for their guidance and feedback on this work over the years. To my lab members, Yefei Pang, Jing Dong, and Md. Saydur Rahman, thank you for your patience in teaching me the protocols and skills that were essential in to research. To my dear friend Susan Lawson, I could not have completed this work without your dedicated care to our wet lab and fish, and I would not have stayed sane without your company and friendship.
    [Show full text]