Sarasota Bay Research Articles

Perfluoroalkylphosphinic Acids in Northern Pike (Esox lucius), Double-Crested Cormorants (Phalacrocorax auritus), and Bottlenose Dolphins (Tursiops truncatus) in Relation to Other Perfluoroalkyl Acids.

Perfluoroalkyl phosphinic acids (PFPIAs) are perfluoroalkyl acids (PFAAs) that are used for their surfactant properties in a variety of applications, resulting in their presence in environmental waters; however, they have not been widely studied in biota. A survey of PFPIAs was conducted in fish, dolphins, and birds from various locations in North America. Northern pike (Esox lucius) were collected at two locations in 2011 near Montréal Island in the St. Lawrence River, Canada, double-crested cormorants (Phalacrocorax auritus) were collected from bird colonies in the Great Lakes in 2010-2012, and bottlenose dolphins (Tursiops truncatus) from Sarasota Bay, FL and Charleston Harbor, SC were sampled in 2004-2009. PFPIAs had a detection frequency of 100% in all animals. This is the first report of PFPIAs in fish, dolphin, and bird plasma. Total PFPIA levels (mean ± standard deviation, 1.87 ± 2.17 ng/g wet weight (ww), range of 0.112-15.3 ng/g ww) were 1-2 orders of magnitude lower than those of perfluoroalkyl carboxylates (PFCA) and perfluoroalkanesulfonates (PFSA) in the same samples. The predominant congeners were 6:8 PFPIA (cormorants and pike) and 6:6 PFPIA (dolphins). Total PFPIAs in cormorants from Hamilton Harbour (5.02 ± 2.80 ng/g ww) were statistically higher than in other areas and taxonomic groups. The ubiquity of PFPIAs warrants further research on sources and effects of these unique compounds.

Disaster Preparedness within the Resiliency Management Framework

이 연구는 미국 플로리다 주의 사라소타 만에 생태환경의 탄력성 조사를 기반으로 재난 발생 시자연적으로 복구 가능한 생태계의 범위 및 관리시스템에 대한 고찰을 다룬 논문이다. 자연재해 발생후 생태계가 자연적으로 복구할 수 있는 탄력성을 갖기 위해 필요한 정책적 준비 및 제도적 장치가 필요한지에 대한 연구를 통해 보다 지속가능한 개발방향에 대해 기술하고 그 필요한 재원에 대해 분석한다. 생태학적 탄력성에 대한 연구는 최근 들어 많은 관심을 받는 주제이지만 이에 대한 자연재해와의 연관성에 대한 연구는 이론적으로나 실증적으로 분석된 부분이 아직까지 많지 않은 상태이다. 따라서 본 연구에서는 생태계의 자연탄력성에 대한 이론적 고찰을 통해 이를 활용한 자연재해 극복 및 대비 방법에 대해 알아보고 그 필요성에 대한 학문적 뒷받침을 제시하여 추후 실증적인 연구가 필요할 경우 그 방향성 및 필요 결과물에 대한 제시를 통해 자연 생태계와 재난방지 분야에 대한 하나의 기준점을 제시한다.Diagnosing a region s ecosystem and its level of resiliency would provide an alternative viewpoint of risk management and disaster preparedness. As a result, the region would become more resilient to its environ-mental vulnerability and long-lasting human impact on the ecosystem. This study is intended to provide a framework to diagnose a region s natural resiliency by assessing possible disturbance, threshold, and the adaptive cycle. These three are critical components to properly understand a region s natural resiliency and thus frequently implemented in various research projects. Using the three key components, we analyzed the levels of resiliency of Sarasota Bay ecosystem in the state of Florida in the U.S. The study findings provide policy guidelines and recommendations for a better disaster preparedness strategy.

Elevated Accumulation of Parabens and their Metabolites in Marine Mammals from the United States Coastal Waters.

The widespread exposure of humans to parabens present in personal care products is well-known. Nevertheless, little is known about the accumulation of parabens in marine organisms. In this study, six parabens and four common metabolites of parabens were measured in 121 tissue samples from eight species of marine mammals collected along the coastal waters of Florida, California, Washington, and Alaska. Methyl paraben (MeP) was the predominant compound found in the majority of the marine mammal tissues analyzed, and the highest concentration found was 865 ng/g (wet weight [wet wt]) in the livers of bottlenose dolphins from Sarasota Bay, FL. 4-Hydroxybenzoic acid (4-HB) was the predominant paraben metabolite found in all tissue samples. The measured concentrations of 4-HB were on the order of hundreds to thousands of ng/g tissue, and these values are some of the highest ever reported in the literature. MeP and 4-HB concentrations showed a significant positive correlation (p < 0.05), which suggested a common source of exposure to these compounds in marine mammals. Trace concentrations of MeP and 4-HB were found in the livers of polar bears from the Chuckchi Sea and Beaufort Sea, which suggested widespread distribution of MeP and 4-HB in the oceanic environment.

Adrenal Hormones in Common Bottlenose Dolphins (Tursiops truncatus): Influential Factors and Reference Intervals.

Inshore common bottlenose dolphins (Tursiops truncatus) are exposed to a broad spectrum of natural and anthropogenic stressors. In response to these stressors, the mammalian adrenal gland releases hormones such as cortisol and aldosterone to maintain physiological and biochemical homeostasis. Consequently, adrenal gland dysfunction results in disruption of hormone secretion and an inappropriate stress response. Our objective herein was to develop diagnostic reference intervals (RIs) for adrenal hormones commonly associated with the stress response (i.e., cortisol, aldosterone) that account for the influence of intrinsic (e.g., age, sex) and extrinsic (e.g., time) factors. Ultimately, these reference intervals will be used to gauge an individual’s response to chase-capture stress and could indicate adrenal abnormalities. Linear mixed models (LMMs) were used to evaluate demographic and sampling factors contributing to differences in serum cortisol and aldosterone concentrations among bottlenose dolphins sampled in Sarasota Bay, Florida, USA (2000–2012). Serum cortisol concentrations were significantly associated with elapsed time from initial stimulation to sample collection (p<0.05), and RIs were constructed using nonparametric methods based on elapsed sampling time for dolphins sampled in less than 30 minutes following net deployment (95% RI: 0.91–4.21 µg/dL) and following biological sampling aboard a research vessel (95% RI: 2.32–6.68 µg/dL). To examine the applicability of the pre-sampling cortisol RI across multiple estuarine stocks, data from three additional southeast U.S. sites were compared, revealing that all of the dolphins sampled from the other sites (N = 34) had cortisol concentrations within the 95th percentile RI. Significant associations between serum concentrations of aldosterone and variables reported in previous studies (i.e., age, elapsed sampling time) were not observed in the current project (p<0.05). Also, approximately 16% of Sarasota Bay bottlenose dolphin aldosterone concentrations were below the assay’s detection limit (11 pg/mL), thus hindering the ability to derive 95th percentile RIs. Serum aldosterone concentrations from animals sampled at the three additional sites were compared to the detection limit, and the proportion of animals with low aldosterone concentrations was not significantly different than an expected prevalence of 16%. Although this study relied upon long-term, free-ranging bottlenose dolphin health data from a single site, the objective RIs can be used for future evaluation of adrenal function among individuals sampled during capture-release health assessments.

Individual specialization in the foraging habits of female bottlenose dolphins living in a trophically diverse and habitat rich estuary.

We examine individual specialization in foraging habits (foraging habitat and trophic level) of female bottlenose dolphins (Tursiops truncatus) resident in Sarasota Bay, Florida, USA, by analyzing time series of stable isotope (δ(15)N and δ(13)C) values in sequential growth layer groups within teeth. The isotope data provide a chronology of foraging habits over the lifetime of the individual and allowed us to show that female bottlenose dolphins exhibit a high degree of individual specialization in both foraging habitat and trophic level. The foraging habits used by adult females are similar to those they used as calves and may be passed down from mother to calf through social learning. We also characterized the foraging habits and home range of each individual by constructing standard ellipses from isotope values and dolphin sightings data (latitude and longitude), respectively. These data show that Sarasota Bay bottlenose dolphins forage within a subset of the habitats in which they are observed. Moreover, females with similar observational standard ellipses often possessed different foraging specializations. Female bottlenose dolphins may demonstrate individual specialization in foraging habits because it reduces some of the cost of living in groups, such as competition for prey.

Biomarkers of brevetoxin exposure and composite toxin levels in hard clam (Mercenaria sp.) exposed to Karenia brevis blooms.

Brevetoxins in clams (Mercenaria sp.) exposed to recurring blooms of Karenia brevis in Sarasota Bay, FL, were studied over a three-year period. Brevetoxin profiles in toxic clams were generated by ELISA and LC-MS. Several brevetoxin metabolites, as identified by LC-MS, were major contributors to the composite brevetoxin response of ELISA. These were S-desoxyBTX-B2 (m/z 1018), BTX-B2 (m/z 1034), BTX-B5 (m/z 911), open A-ring BTX-B5 (m/z 929), and BTX-B1 (m/z 1018). Summed values of these metabolites were highly correlated (R(2)=0.9) with composite B-type brevetoxin measurements by ELISA. S-desoxyBTX-B2, BTX-B2, and BTX-B1 were the most persistent and detectable in shellfish for several months after dissipation of blooms. These metabolites were selected as LC-MS biomarkers of brevetoxin exposure and reflective of composite B-type brevetoxins in hard clam. ELISA and LC-MS values were moderately correlated with toxicity of the shellfish by mouse bioassay. ELISA and LC-MS methods offer rapid screening and confirmatory determination of brevetoxins, respectively, as well as toxicity assessment in clams exposed to K.brevis blooms.

Dolphins and diabetes: applying one health for breakthrough discoveries.

Dolphins and diabetes: applying one health for breakthrough discoveries.

Microarray applications to understand the impact of exposure to environmental contaminants in wild dolphins (Tursiops truncatus)

It is increasingly common to monitor the marine environment and establish geographic trends of environmental contamination by measuring contaminant levels in animals from higher trophic levels. The health of an ecosystem is largely reflected in the health of its inhabitants. As an apex predator, the common bottlenose dolphin (Tursiops truncatus) can reflect the health of near shore marine ecosystems, and reflect coastal threats that pose risk to human health, such as legacy contaminants or marine toxins, e.g. polychlorinated biphenyls (PCBs) and brevetoxins. Major advances in the understanding of dolphin biology and the unique adaptations of these animals in response to the marine environment are being made as a result of the development of cell-lines for use in in vitro experiments, the production of monoclonal antibodies to recognize dolphin proteins, the development of dolphin DNA microarrays to measure global gene expression and the sequencing of the dolphin genome. These advances may play a central role in understanding the complex and specialized biology of the dolphin with regard to how this species responds to an array of environmental insults.This work presents the creation, characterization and application of a new molecular tool to better understand the complex and unique biology of the common bottlenose dolphin and its response to environmental stress and infection. A dolphin oligo microarray representing 24,418 unigene sequences was developed and used to analyze blood samples collected from 69 dolphins during capture-release health assessments at five geographic locations (Beaufort, NC, Sarasota Bay, FL, Saint Joseph Bay, FL, Sapelo Island, GA and Brunswick, GA). The microarray was validated and tested for its ability to: 1) distinguish male from female dolphins; 2) differentiate dolphins inhabiting different geographic locations (Atlantic coasts vs the Gulf of Mexico); and 3) study in detail dolphins resident in one site, the Georgia coast, known to be heavily contaminated by Aroclor 1268, an uncommon polychlorinated (PCB) mixture. The microarray was able to distinguish dolphins by sex, geographic location, and corroborate previously published health irregularities for the Georgia dolphins. Genes involved in xenobiotic metabolism, development/differentiation and oncogenic pathways were found to be differentially expressed in GA dolphins. The report bridges the advancements in dolphin genome sequencing to the first step towards providing a cost-effective means to screen for indicators of chemical toxin exposure as well as disease status in top level predators.

Identification and characteristics of signature whistles in wild bottlenose dolphins (Tursiops truncatus) from Namibia.

A signature whistle type is a learned, individually distinctive whistle type in a dolphin's acoustic repertoire that broadcasts the identity of the whistle owner. The acquisition and use of signature whistles indicates complex cognitive functioning that requires wider investigation in wild dolphin populations. Here we identify signature whistle types from a population of approximately 100 wild common bottlenose dolphins (Tursiops truncatus) inhabiting Walvis Bay, and describe signature whistle occurrence, acoustic parameters and temporal production. A catalogue of 43 repeatedly emitted whistle types (REWTs) was generated by analysing 79 hrs of acoustic recordings. From this, 28 signature whistle types were identified using a method based on the temporal patterns in whistle sequences. A visual classification task conducted by 5 naïve judges showed high levels of agreement in classification of whistles (Fleiss-Kappa statistic, κ = 0.848, Z = 55.3, P<0.001) and supported our categorisation. Signature whistle structure remained stable over time and location, with most types (82%) recorded in 2 or more years, and 4 identified at Walvis Bay and a second field site approximately 450 km away. Whistle acoustic parameters were consistent with those of signature whistles documented in Sarasota Bay (Florida, USA). We provide evidence of possible two-voice signature whistle production by a common bottlenose dolphin. Although signature whistle types have potential use as a marker for studying individual habitat use, we only identified approximately 28% of those from the Walvis Bay population, despite considerable recording effort. We found that signature whistle type diversity was higher in larger dolphin groups and groups with calves present. This is the first study describing signature whistles in a wild free-ranging T. truncatus population inhabiting African waters and it provides a baseline on which more in depth behavioural studies can be based.

Fetal Survival of Common Bottlenose Dolphins (Tursiops truncatus) in Sarasota Bay, Florida

Fetal Survival of Common Bottlenose Dolphins (Tursiops truncatus) in Sarasota Bay, Florida

Comparative diel oxygen cycles preceding and during a Karenia bloom in Sarasota Bay, Florida, USA

The diel change in dissolved oxygen concentrations were recorded with an automated incubator containing a pulsed oxygen sensor in Sarasota Bay, Florida. The deployments occurred during a ‘pre-bloom’ period in May to June 2006, and during a harmful algal bloom dominated by Karenia brevis in September 2006. The diurnal (daylight) increase in dissolved oxygen concentrations varied from 16 to 104μmolO2l−1 with the corresponding nocturnal decrease in oxygen varying from 16 to 77μmolO2l−1. Nocturnal respiration consumed 42–113% of the diurnal net oxygen production with the minimum and maximum during the pre-bloom period. Hourly production rates closely followed fluctuations in irradiance with maximum rates in the late morning. Hourly oxygen utilization rates (community respiration) at night were highest during the first few hours after sunset.

Carcass‐recovery rates for resident bottlenose dolphins in Sarasota Bay, Florida

Carcass‐recovery rates for resident bottlenose dolphins in Sarasota Bay, Florida

Bacteriocidal effects of brevetoxin on natural microbial communities

The sensitivity of bacteria to the marine neurotoxins, brevetoxins, produced by the dinoflagellate Karenia brevis and raphidophytes Chattonella spp. remains an open question. We investigated the bacteriocidal effects of brevetoxin (PbTx-2) on the abundance and community composition of natural microbial communities by adding it to microbes from three coastal marine locations that have varying degrees of historical brevetoxin exposure: (1) Great Bay, New Jersey, (2) Rehoboth Bay, Delaware and (3) Sarasota Bay, Florida. The populations with limited or no documented exposure were more susceptible to the effects of PbTx-2 than the Gulf of Mexico populations which are frequently exposed to brevetoxins. The community with no prior documented exposure to brevetoxins showed significant (p=0.03) changes in bacterial abundance occurring with additions greater than 2.5μgPbTx-2L−1. Brevetoxin concentrations during K. brevis blooms range from ∼2.5 to nearly 100μgL−1 with typical concentrations of ∼10–30μgL−1. In contrast to the unexposed populations, there was no significant decrease in bacterial cell number for the microbial community that was frequently exposed to brevetoxins, which implies variable sensitivity in natural communities. The diversity in the bacterial communities that were sensitive to PbTx-2 declined upon exposure. This suggests that the PbTx-2 was selecting for or against specific species. Mortality was much higher in the 200μgPbTx-2L−1 treatment after 48h and >37% of the species disappeared in the bacterial communities with no documented exposure. These results suggest that toxic red tides may play a role in structuring bacterial communities.

Influences of Channel Deepening and Widening on the Tidal and Nontidal Circulations of Tampa Bay

A high-resolution, three-dimensional coastal ocean circulation model is applied to Tampa Bay to determine the effects that channel deepening and widening may have on the estuary’s tidal and nontidal circulations. The model domain includes all of Tampa Bay, Sarasota Bay, the Intra-coastal Waterway, and the adjoining rivers. With resolution as high as 20 m, the model resolves the main shipping channels, the bridge causeways, and all important inlet mass conveyances. Model evaluations are made against in situ data and a previously published, relatively lower-resolution version. By deepening and widening the shipping channels for the purpose of accommodating larger vessels, our results suggest an increase in tidal range and a decrease in tidal phase from the mouth to the head of the bay. Along with these tidal effects, our results also suggest an increase in the nontidal circulation, resulting in an increase in salinity and attendant consequences to the estuary’s ecology.

Machine learning approaches to investigate the impact of PCBs on the transcriptome of the common bottlenose dolphin (Tursiops truncatus)

As top-level predators, common bottlenose dolphins (Tursiops truncatus) are particularly sensitive to chemical and biological contaminants that accumulate and biomagnify in the marine food chain.This work investigates the potential use of microarray technology and gene expression profile analysis to screen common bottlenose dolphins for exposure to environmental contaminants through the immunological and/or endocrine perturbations associated with these agents. A dolphin microarray representing 24,418 unigene sequences was used to analyze blood samples collected from 47 dolphins during capture-release health assessments from five different US coastal locations (Beaufort, NC, Sarasota Bay, FL, Saint Joseph Bay, FL, Sapelo Island, GA and Brunswick, GA). Organohalogen contaminants including pesticides, polychlorinated biphenyl congeners (PCBs) and polybrominated diphenyl ether congeners were determined in blubber biopsy samples from the same animals. A subset of samples (n = 10, males; n = 8, females) with the highest and the lowest measured values of PCBs in their blubber was used as strata to determine the differential gene expression of the exposure extremes through machine learning classification algorithms. A set of genes associated primarily with nuclear and DNA stability, cell division and apoptosis regulation, intra- and extra-cellular traffic, and immune response activation was selected by the algorithm for identifying the two exposure extremes. In order to test the hypothesis that these gene expression patterns reflect PCB exposure, we next investigated the blood transcriptomes of the remaining dolphin samples using machine-learning approaches, including K-nn and Support Vector Machines classifiers. Using the derived gene sets, the algorithms worked very well (100% success rate) at classifying dolphins according to the contaminant load accumulated in their blubber. These results suggest that gene expression profile analysis may provide a valuable means to screen for indicators of chemical exposure.

Modeling Mercury Distribution in the Sarasota Bay Ecosystem Using SERAFM and Stable Isotope Ratios of Nitrogen (δ15N) in Biota

Abstract Conversion of CH3Hg+ concentrations in water to CH3Hg+ concentrations in fish tissue is critically important in characterizing Hg health risks to humans and biota in aquatic ecosystems. However, this is a challenging task due to complex biogeochemical CH3Hg+ processes that are replete with uncertainty. In the present study, the uncertainty was reduced by employing the Spreadsheet-based Ecological Risk Assessment for the Fate of Mercury (SERAFM) model and a linear relationship between logarithmic Hg concentrations and stable isotope ratios of nitrogen (δ15N) in biota. By using this approach, the fate, transport, and bioaccumulation of CH3Hg+ in Sarasota Bay, FL, was modeled. Modeling results suggest that ∼60% of the total Hg loading (8.7 kg/year) to the Sarasota Bay in 2011 originated from atmospheric Hg deposition to the watershed with subsequent transport to the waterbody via stormwater runoff. This indicated that watershed runoff could be an important source of Hg to a bay adjacent to highly ur...

Health of Common Bottlenose Dolphins (Tursiops truncatus) in Barataria Bay, Louisiana, Following the Deepwater Horizon Oil Spill

The oil spill resulting from the explosion of the Deepwater Horizon drilling platform initiated immediate concern for marine wildlife, including common bottlenose dolphins in sensitive coastal habitats. To evaluate potential sublethal effects on dolphins, health assessments were conducted in Barataria Bay, Louisiana, an area that received heavy and prolonged oiling, and in a reference site, Sarasota Bay, Florida, where oil was not observed. Dolphins were temporarily captured, received a veterinary examination, and were then released. Dolphins sampled in Barataria Bay showed evidence of hypoadrenocorticism, consistent with adrenal toxicity as previously reported for laboratory mammals exposed to oil. Barataria Bay dolphins were 5 times more likely to have moderate-severe lung disease, generally characterized by significant alveolar interstitial syndrome, lung masses, and pulmonary consolidation. Of 29 dolphins evaluated from Barataria Bay, 48% were given a guarded or worse prognosis, and 17% were considered poor or grave, indicating that they were not expected to survive. Disease conditions in Barataria Bay dolphins were significantly greater in prevalence and severity than those in Sarasota Bay dolphins, as well as those previously reported in other wild dolphin populations. Many disease conditions observed in Barataria Bay dolphins are uncommon but consistent with petroleum hydrocarbon exposure and toxicity.

Insights into a complex communication system from tagged bottlenose dolphins

Since 2011, we have deployed 30 acoustic and movement logging DTAGs on long-term, multi-generational resident bottlenose dolphins in Sarasota Bay, Florida, for a total of approximately 140 h. Twenty-two tags were deployed simultaneously on pairs of associated individuals, allowing for greater resolution of individual vocal activity. Virtually all dolphins in the Sarasota Bay community are identifiable both visually and by means of their individually distinctive signature whistles. Tags were attached during brief capture-release health assessments, and behavioral observations of tagged individuals post-release continued for as long as possible. Tag data reveal unique insights into foraging behavior, including distinctive acoustic and movement patterns associated with particular foraging modes (e.g., “pinwheel feeding”). In addition to echolocation clicks and buzzes, several distinctive pulsed sounds were recorded on the tags. Whistle copying was observed 18 times in a preliminary analysis of approximately two hours of data, and at least one instance involved more than two dolphins producing the same whistle. Finally, we obtained evidence for at least one shared, stereotyped non-signature whistle. Combining extensive longitudinal information on individual dolphins with fine scale behavioral and acoustic data provides tremendous opportunities for describing and quantifying the complexity of the bottlenose dolphin communication system.

Distribution of mercury and selenium in blood compartments of bottlenose dolphins (Tursiops truncatus) from Sarasota Bay, Florida

Total mercury and selenium concentrations ([THg], [Se]) in serum, plasma, whole blood, and packed cells were examined in a resident population of free-ranging bottlenose dolphins (Tursiops truncatus) from Sarasota Bay, Florida, USA. The authors determined how these elements partition in blood and assess compartment-specific associations. Determining the distribution of Se and THg can provide physiologic insight into potential association of Hg with selenol-containing biomolecules (e.g., antioxidants) in blood compartments. Concentrations of THg were ranked serum < plasma < whole blood < packed cells; whereas for Se concentrations, plasma < serum < whole blood < packed cells. The Se:THg molar ratio was greater than 1 in all compartments, with the higher ratios found in serum and plasma (plasma < serum) and the lower in whole blood and packed cells (packed cells < whole blood). Age was positively correlated with [THg] in all blood compartments and with [Se] in serum, plasma, and whole blood. Age was negatively correlated with Se:THg molar ratios in all blood compartments, driven by low [THg] in young animals. Although [THg] was highly correlated among all blood compartments, this was not the case for [Se]. The feasibility of calculating packed cell [THg], [Se], and Se:THg molar ratios using hematocrit measurements in combination with whole blood and plasma [THg] and [Se] was validated, allowing routine assessment of compartmentalization within erythrocytes using standard clinical measurements.

Abundance and Distribution of Large Marine Gastropods in Nearshore Seagrass Beds Along the Gulf Coast of Florida

Local abundance was estimated and distribution determined for selected large gastropod species based on observations made during underwater visual surveys at 10 sites along the Gulf coast of Florida each summer from 2009 through 2012. The total number of tulip snails (Fasciolaria spp., including the true tulip, Fasciolaria tulipa, and banded tulip, Fasciolaria lilium), lightning whelk (Busycon sinistrum), and horse conch (Triplofusus giganteus) were counted at 190 stations (each 600 m2) each year in shallow-water seagrass beds. Tulip snails were observed most frequently, with a mean density of 1.93 ± 3.56 snails/ 600 m2, with substantially fewer lightning whelks (0.29 ± 1.04/600 m2) and horse conchs (0.10 ± 0.37/600 m2) observed. Horse conchs were distributed more evenly across the 4 Gulf coast regions studied: Panhandle, Big Bend, Nature Coast, and South. Tulip snails were most abundant in the Panhandle and the South, whereas lightning whelks were found predominantly in the South. Snail counts peaked in 2010 and were greatest at the Pine Island Sound site, although mean density was greatest in Sarasota Bay (2.2 snails/600 m2). Snails were observed most frequently at the St. Joseph Bay site, where they were present at 74 of the 80 stations surveyed. Statewide commercial fisheries landings data were examined for years 1994 through 2011 and totaled 130,710 true tulip snails (banded tulip snails were not included), 72,230 lightning whelks, and 33,087 horse conchs. The total number landed of both lightning whelks and horse conchs was greater on the west coast of Florida, whereas the total number of true tulip snails landed was greater on the east coast.