To examine variation in diet and daily ration of the bonnethead, Sphyrna tiburo (Linnaeus, 1758), sharks were collected from three areas in the eastern Gulf of Mexico: northwest Florida (29o40N, 85o13W), Anclote Key near Tampa Bay (28o10N, 82o42.5W), and Florida Bay (24o50N, 80o48W) from March through September, 1998-2000. In each area, diet was assessed by life stage (young-of-the year, juveniles, and adults) and quantified using five indices: percent by number (N), percent by weight (W), frequency of occurrence (O), index of relative importance expressed on a percent basis (IRI), and IRI based on diet category (IRIDC). Diet could not be assessed for young-of-the-year in Tampa Bay or Florida Bay owing to low sample size. Diet analysis showed an ontogenetic shift in northwest Florida. Young-of-the-year stomachs from northwest Florida (n68, 1 empty) contained a mix of seagrass and crustaceans while juvenile stomachs (n82, 0 empty) contained a mix of crabs and seagrass and adult stomachs (n39, 1 empty) contained almost exclusively crabs. Crabs made up the majority of both juvenile and adult diet in Tampa Bay (n79, 2 empty, and n88, 1 empty, respectively). Juvenile stomachs from Florida Bay (n72, 0 empty) contained seagrass and a mix of crustaceans while adult stomachs contained more shrimp and cephalopods (n82, 3 empty). Diets in northwest Florida and Tampa Bay were similar. The diet in Florida Bay was different from those in the other two areas, consisting of fewer crabs and more cephalopods and lobsters. Plant material was found in large quantities in all stomachs examined from all locations (15 IRIDC in 6 of the 7 life stage-area combinations, 30 IRIDC in 4 of the 7 combinations, and 62 IRIDC in young-of-the-year diet in northwest Florida). Using species- and area-specific inputs, a bioenergetic model was constructed to estimate daily ration. Models were constructed under two scenarios: assuming plant material was and was not part of the diet. Overall, daily ration was significantly different by sex, life stage, and region. The bioenergetic model predicted increasing daily ration with decreasing latitude and decreasing daily ration with ontogeny regardless of the inclusion or exclusion of plant material. These results provide evidence that bonnetheads continuously exposed to warmer temperatures have elevated metabolism and require additional energy consumption to maintain growth and reproduction.

The Gulf of Mexico Shark Pupping and Nursery (GULFSPAN) survey is a NOAA-led fishery-independent survey that examines the distribution and abundance of juvenile sharks in coastal areas of the Gulf of Mexico. The data describe coastal shark abundance, based on paired gillnet and longline surveys conducted monthly from April to October, and environmental data from Tampa Bay.

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The identification of essential habitats for marine species is critical for proper management of populations. Although the species composition of sharks that occur in coastal waters is diverse, descriptions of distribution and habitat use tend to be generalized; distribution has been broadly outlined in which individuals are segregated into different habitats by ontogeny The GULFPSAN survey is a fishery-independent survey that began in 1994 to examine the distribution and abundance of juvenile sharks in coastal areas of the Gulf of Mexico. It was done adhoc through 2002. In 2003 it began to receive its own funding. The database describes coastal shark abundance and environmental data from St. Andrews Bay to Apalachicola Bay in the northeastern Gulf of Mexico.

The Gulf of Mexico Shark Pupping and Nursery (GULFSPAN) survey is a fishery-independent survey that began in 1994 to examine the distribution and abundance of juvenile sharks in coastal areas of the Gulf of Mexico. The data describes coastal shark abundance and environmental data from St. Andrews Bay to Apalachicola Bay in the northeastern Gulf of Mexico.

These data sets contain raw and processed data to compare life history demographic information necessary to manage spotted seatrout in NW Florida. Specific objectives were to develop estuary-specific information on age growth, mortality rates, spawning seasonality, age size at maturity, and age size composition of the recreational fishery for Apalachicola, St. Joseph, St. Andrew, Choctawhatchee, Pensacola, and Perdido Bay systems.

PURPOSE: Support age-structured population stock assessments and research on fish growth. DESCRIPTION: Fish otoliths are collected from scientific surveys, fisheries observers on fishing vessels and from scientific sampling of commercial fisheries. The otoliths collected are placed in paper envelopes, recorded and held in a climate-controlled storage facility. Age determination is performed yearly on available samples. Digital images of each pair of otoliths collected are captured when possible. The information made available through this metadata record is the summary of otoliths present in the collection at the Gulf Fisheries Centre in Moncton, NB, Canada. The number of otoliths available from different sources by year and month is provided for the following stocks: - Atlantic Cod NAFO Divisions 4T / 4VN (Nov. to Apr.) - White Hake NAFO Division 4T - American Plaice NAFO Division 4T - Winter Flounder NAFO Division 4T - Yellowtail Flounder NAFO Division 4T - Witch Flounder NAFO Divisions 4RST - Skate species NAFO Division 4T There is additional information of observed sex, length, weight and age information of fish specimens made by trained Fisheries and Oceans Canada technicians that can be made available upon request. PARAMETERS COLLECTED: length (biological), age (biological) NOTES ON QUALITY CONTROL: Reference collections for certain species exist and are used to train technicians and to calibrate the age readings obtained by the fisheries technicians that use the otoliths for age estimation. Digital images of the otoliths that are part of the reference collection are available and used for calibration and training purposes. The otolith images are also authoritatively annotated by fisheries technicians. PHYSICAL SAMPLE DETAILS: Fish otoliths, skate vertebrae SAMPLING METHODS: Marine fish otoliths are obtained from fish specimens collected during research surveys and during scientific sampling of commercial fisheries. The sagittal otoliths are removed from sampled specimens, recorded, placed in a protective medium and held in a climate-controlled storage facility. Digital images of each pair of otoliths collected are captured when possible. USE LIMITATION: To ensure scientific integrity and appropriate use of the data, we would encourage you to contact the data custodian.

This dataset reports plankton species abundance from 13 sites off the Florida Panhandle Bight at the head of DeSoto Canyon aboard the R/V Bellows cruise BE-1311 on December 12-14, 2012. Plankton samples were collected using a net with mesh size of 25 micrometer and 0.5m diameter. This dataset reports the location, date, time, and length of tow for each sample. Plankton species were categorized as Ceratium spp., Dinophysis spp., other dinoflagellates, Chaetoceros/Bacteriastrum spp., Rhizosolenia/Guinardia spp, Eucampia/Hemiaulus spp., other chain-forming diatoms, Thalassionematales spp., Nitzschioid diatoms, other diatoms, Cyanobacteria (Trichodesmium spp.), and zooplankton. Abundances were recorded as individual counts as well as percentages of total sample. Quantitative phytoplankton profiles were taken specifically at 4 sites (P1, P3, P5, P7). For this, one-liter samples were collected from the surface and at different depths using Niskin bottles. Samples were filtered onto a 0.45 micrometer nitrocellulose filter and air-dried. A portion of each filter was mounted on an aluminum stub, sputter-coated, and examined with a JEOL JSM-6480 LV scanning electron microscope. Diatoms, coccolithophores, and armored dinoflagellates were identified to the lowest possible taxonomic category. The number of cells of each taxon in a field of view at a magnification of 1000x was recorded, with up to 700 fields-of-view examined, depending on the density of phytoplankton in the sample. The dataset includes the depth, the volume filtered, the number of cells of each taxon counted, and the calculated abundance of each taxon in cells per liter. Micrographs taken during the analysis are included.

Juvenile scalloped hammerhead sharks, Sphyrna lewini, were collected in northwest Florida to examine foraging ecology, bioenergetics, and trophic level (30-60 cm FL mean FL 41.5 cm n 196). Diet analysis was performed using single and compound measures of prey quantity. Diet was also analyzed using seven broad diet categories (DC). Diet composition and estimated daily ration were compared to previously published information on bonnethead sharks, S. tiburo. Diet overlap was low between species. Juvenile S. lewini feed on relatively small (85 of prey items 5 shark length) teleosts (mostly bothids and sciaenids) and shrimps, whereas S. tiburo have been documented to feed mostly on crustaceans and plant material in northwest Florida. Plant material contributed little to the diet of S. lewini. Estimated daily ration was significantly lower for S. lewini (4.6 BW d-1) than for S. tiburo in northwest Florida, regardless if plant material was included in the model (p0.02 including and p0.00001 excluding plant material). Trophic level was calculated at 4.0 for S. lewini and 2.6 for S. tiburo. Stable isotope analysis showed S. lewini had significantly higher 15N values and significantly lower 13C values than S. tiburo, supporting the difference observed in calculated trophic level. These results provide evidence that small juvenile hammerhead species co-exist in coastal northwest Florida by feeding at separate trophic levels.