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Characterization of Elasmobranch Community Dynamics in the Indian River Lagoon
Title
Characterization of Elasmobranch Community Dynamics in the Indian River Lagoon.
Creator
Roskar, Amelia Grace, Ajemian, Matthew, Florida Atlantic University, Charles E. Schmidt College of Science, Depament of Biological Sciences
Abstract/Description
Florida’s Indian River Lagoon (IRL) has experienced myriad anthropogenic impacts and knowledge on elasmobranchs (sharks and rays) in the southern IRL is lacking. A fishery independent survey (longline/gillnet) was implemented to 1) assess the effects of bait type [striped mullet (Mugil cephalus) versus Atlantic mackerel (Scomber scombrus)] and mesh size (15.2 cm versus 20.3 cm stretch mesh) on elasmobranch species composition, catch-per-unit effort, and size distributions and 2) characterize...
Show moreFlorida’s Indian River Lagoon (IRL) has experienced myriad anthropogenic impacts and knowledge on elasmobranchs (sharks and rays) in the southern IRL is lacking. A fishery independent survey (longline/gillnet) was implemented to 1) assess the effects of bait type [striped mullet (Mugil cephalus) versus Atlantic mackerel (Scomber scombrus)] and mesh size (15.2 cm versus 20.3 cm stretch mesh) on elasmobranch species composition, catch-per-unit effort, and size distributions and 2) characterize elasmobranch abundance and distribution. From 2016 - 2018, 630 individuals (16 species) were captured, more often in the gillnet than the longline. Catch-per-unit-effort was significantly higher with mullet than mackerel. Species composition differed among gears. Although dependent on gear, there was evidence of seasonal and spatial patterns in abundance and species composition. This study provides the first baseline abundance indices for many elasmobranchs in the IRL and develops the capacity to understand how elasmobranchs may respond to changes in this highly modified estuary.
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Date Issued
2019
PURL
http://purl.flvc.org/fau/fd/FA00013256
Subject Headings
Indian River (Fla : Lagoon)--Environmental conditions, Elasmobranchs, Sharks--Ecology, Rays (Fishes)--Ecology
Format
Document (PDF)
Movement and Habitat Use of Whitespotted Eagle Rays, Aetobatus narinari, throughout Florida
Title
Movement and Habitat Use of Whitespotted Eagle Rays, Aetobatus narinari, throughout Florida.
Creator
DeGroot, Breanna Clarice, Ajemian, Matthew, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description
Elasmobranchs play ecologically important roles in coastal environments. Unfortunately, the basic distribution and movement patterns of these species, particularly rays, remain relatively unknown. This is especially true for the Whitespotted Eagle Ray (Aetobatus narinari), a protected species in Florida with poorly described migratory and habitat use patterns. I employed a combination of acoustic telemetry techniques to reveal multi-scale spatial patterns of A. narinari around Florida....
Show moreElasmobranchs play ecologically important roles in coastal environments. Unfortunately, the basic distribution and movement patterns of these species, particularly rays, remain relatively unknown. This is especially true for the Whitespotted Eagle Ray (Aetobatus narinari), a protected species in Florida with poorly described migratory and habitat use patterns. I employed a combination of acoustic telemetry techniques to reveal multi-scale spatial patterns of A. narinari around Florida. Movement patterns between the east and west coast individuals were distinct; a majority of west coast tagged A. narinari exhibited migratory or transient behavior while most east coast tagged individuals remained resident in the Indian River Lagoon. Fine-scale tracking of A. narinari revealed individuals spent a large percentage of time in the inlets and channels and frequently reused habitats parallel to the shore. This study fills a knowledge gap on the species ecology which may be used for adaptive management strategies throughout A. narinari’s range.
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Date Issued
2018
PURL
http://purl.flvc.org/fau/fd/FA00013116
Subject Headings
Aetobatus narinari, Spotted eagle ray, Chondrichthyes--Ecology, Elasmobranchs, Biotelemetry, Acoustic telemetry
Format
Document (PDF)
Reproductive Development of Female Bonefish (Albula spp.) from the Bahamas
Title
Reproductive Development of Female Bonefish (Albula spp.) from the Bahamas.
Creator
Luck, Cameron Alexander, Ajemian, Matthew J., Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description
Bonefish (Albula spp.) support an economically important sport fishery, yet little is known regarding the reproductive biology of this genus. Analysis of oocytes histology and sex hormone levels was conducted on wild female bonefish sampled during and outside the spawning season in Grand Bahama, Central Andros, and South Andros, The Bahamas to assess reproductive state. Bonefish are commonly found along shallow water flats, or in pre-spawn aggregations (PSA) during spawning months. 17β...
Show moreBonefish (Albula spp.) support an economically important sport fishery, yet little is known regarding the reproductive biology of this genus. Analysis of oocytes histology and sex hormone levels was conducted on wild female bonefish sampled during and outside the spawning season in Grand Bahama, Central Andros, and South Andros, The Bahamas to assess reproductive state. Bonefish are commonly found along shallow water flats, or in pre-spawn aggregations (PSA) during spawning months. 17β-estradiol levels suggest vitellogenic consistency between habitats. However, fish are more reproductively developed at PSA based on the occurrence of larger, more prevalent vitellogenic oocytes and evidence of final maturation. Variability in hormone levels and spawning readiness existed between Grand Bahama and Andros PSAs, suggesting peak spawning may differ by region. Findings from this study will contribute baseline data to the captive bonefish restoration project at Harbor Branch Oceanographic Institute and to the limited ecological data regarding bonefish reproduction.
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Date Issued
2018
PURL
http://purl.flvc.org/fau/fd/FA00013133
Subject Headings
Bonefish, Bahamas, Fishes--Reproduction, Fishes--Spawning, Reproductive biology, Albula
Format
Document (PDF)
THREE-DIMENSIONAL MOVEMENT AND HABITAT USE OF YOUNG WHITE SHARKS (CARCHARODON CARCHARIAS) IN THE NORTHWEST ATLANTIC OCEAN
Title
THREE-DIMENSIONAL MOVEMENT AND HABITAT USE OF YOUNG WHITE SHARKS (CARCHARODON CARCHARIAS) IN THE NORTHWEST ATLANTIC OCEAN.
Creator
Shaw, Rachel Lynn, Ajemian, Matthew, Florida Atlantic University, Department of Biological Sciences, Charles E. Schmidt College of Science
Abstract/Description
Recent research confirmed white shark (Carcharodon carcharias) nursery habitat off Long Island, New York; however, additional research is required to determine the habitat use and fine-scale movements of young-of-the-year and juvenile white sharks within this nursery. Between 2016 and 2019, twenty-five white sharks were fitted with satellite and acoustic tags to better define habitat use. Individuals exhibited horizontal movements parallel to Long Island’s southern shoreline and coastal New...
Show moreRecent research confirmed white shark (Carcharodon carcharias) nursery habitat off Long Island, New York; however, additional research is required to determine the habitat use and fine-scale movements of young-of-the-year and juvenile white sharks within this nursery. Between 2016 and 2019, twenty-five white sharks were fitted with satellite and acoustic tags to better define habitat use. Individuals exhibited horizontal movements parallel to Long Island’s southern shoreline and coastal New Jersey. Log-likelihood chi-square analyses determined preference for water column depth, SSTs, sea surface salinities, and chlorophyll a concentration. Vertical analysis of diving behavior revealed swimming behavior primarily in the upper 20 m of the water column, in temperatures between 18°C and 20°C. Generalized additive mixed modeling suggested SSTs above 20.5°C affected dive depth. These results can help improve characterization of essential fish habitat for young white sharks and provide data to determine the species’ susceptibility to anthropogenic activities.
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Date Issued
2020
PURL
http://purl.flvc.org/fau/fd/FA00013440
Subject Headings
Carcharodon carcharias, White shark, Marine nurseries, Sharks--Ecology
Format
Document (PDF)
INTERACTIONS OF LARGE BENTHOPELAGIC MESOPREDATORS WITH SHELLFISH ENHANCEMENT ACTIVITIES IN FLORIDA COASTAL WATERS
Title
INTERACTIONS OF LARGE BENTHOPELAGIC MESOPREDATORS WITH SHELLFISH ENHANCEMENT ACTIVITIES IN FLORIDA COASTAL WATERS.
Creator
Cahill, Brianna Violet, Ajemian, Matthew, Florida Atlantic University, Department of Marine Science and Oceanography, Charles E. Schmidt College of Science
Abstract/Description
Shellfish aquaculture “grow-out” sites for Northern Quahog (Mercenaria mercenaria) clams have substantially higher densities than the surrounding ambient environment and thus can attract local molluscivores to these areas. I used acoustic telemetry to examine potential interactions of two highly mobile ray species (cownose ray, whitespotted eagle ray) with two clam grow-out sites in the Indian River Lagoon near Sebastian, FL, where clammers have reported damaged grow-out gear. Visitation...
Show moreShellfish aquaculture “grow-out” sites for Northern Quahog (Mercenaria mercenaria) clams have substantially higher densities than the surrounding ambient environment and thus can attract local molluscivores to these areas. I used acoustic telemetry to examine potential interactions of two highly mobile ray species (cownose ray, whitespotted eagle ray) with two clam grow-out sites in the Indian River Lagoon near Sebastian, FL, where clammers have reported damaged grow-out gear. Visitation patterns of telemetered rays to these sites were compared to other reference sites in the region and modeled using local environmental data. While both species spent greater time elsewhere, I found many instances in which rays remained within range of clam grow-out sites for extended periods (>60 minutes). Mesocosm experiments with whitespotted eagle rays confirmed they were capable of interacting with and damaging clams housed within antipredator materials, although mortality was significantly reduced compared to controls and in particular by multi-layer netting.
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Date Issued
2021
PURL
http://purl.flvc.org/fau/fd/FA00013840
Subject Headings
Shellfish fisheries--Florida, Northern quahog, Predators, Biotelemetry
Format
Document (PDF)
RESOLVING HABITAT GAPS FOR BONEFISH CONSERVATION ACROSS FLORIDA AND THE BAHAMAS
Title
RESOLVING HABITAT GAPS FOR BONEFISH CONSERVATION ACROSS FLORIDA AND THE BAHAMAS.
Creator
Lombardo, Steven Michael, Ajemian, Matthew J., Florida Atlantic University, Department of Marine Science and Oceanography, Charles E. Schmidt College of Science
Abstract/Description
Bonefish Albula vulpes are an economically important sport fish that has historically bolstered the recreational flats fisheries of the Florida Keys and The Bahamas; an industry with an annual economic impact of US$465 million and US$169 million, respectively. Analyses of fishing guide logbooks and guide interviews indicate that the population of bonefish in south Florida has declined. Due to the economic and cultural importance of these fisheries, protection of spawning and nursery habitats...
Show moreBonefish Albula vulpes are an economically important sport fish that has historically bolstered the recreational flats fisheries of the Florida Keys and The Bahamas; an industry with an annual economic impact of US$465 million and US$169 million, respectively. Analyses of fishing guide logbooks and guide interviews indicate that the population of bonefish in south Florida has declined. Due to the economic and cultural importance of these fisheries, protection of spawning and nursery habitats is integral to population recovery and stability. However, knowledge gaps persist in how abiotic and biotic habitat factors influence reproduction and recruitment. Without clear delineation of spawning and recruitment habitats, bonefish populations remain vulnerable to anthropogenic disturbances. Bonefish partake in a unique three-point spawning migration, migrating from shallow-water home flats to form nearshore pre-spawning aggregations (PSA) before moving offshore to spawn. Using active acoustic telemetry, sonar imagery, and CTD profiles, the first complete account of offshore spawning movements and novel deep diving behavior was accomplished. Bonefish reached depths of 137.9 m and spawned at 67.3 m, a depth associated with the pycnocline/thermocline. Previous efforts show spatiotemporal plasticity in spawning, a behavior counter to other aggregation forming fishes.
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Date Issued
2022
PURL
http://purl.flvc.org/fau/fd/FA00013899
Subject Headings
Bonefish, Bonefish fisheries, Habitat conservation, Florida, Bahamas
Format
Document (PDF)