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Trophic Interactions, Habitat Use, and Pollution Loads of Bottlenose Dolphins (Tursiops Truncatus) in the Florida Coastal Everglades, Florida, USA, 2013-2019


At a Glance


(Zip file containing 2 files)

Authors: Valeria Paz, Michael Heithaus, Jeremy Kiszka , Kirk Gastrich
Time period: 2013-02-27 to 2019-02-22
Package id: knb-lter-fce.1243.1

How to cite:
Paz, V., M. Heithaus, J. Kiszka , K. Gastrich. 2023. Trophic Interactions, Habitat Use, and Pollution Loads of Bottlenose Dolphins (Tursiops Truncatus) in the Florida Coastal Everglades, Florida, USA, 2013-2019. Environmental Data Initiative. https://doi.org/10.6073/pasta/4da8a26388dc34d5f86e26eeb74a4a84. Dataset accessed 2024-02-26.

Geographic Coverage
This data set contains the following files.

2023_LTER_DolphinBiopsy
Bottlenose Dolphin Biopsy data- Isotopes, age, total mercury and selenium
Attribute table details     Download

2023_LTER_Dolphin_Prey
Prey targeted by bottlenose dolphins- Isotopes, total mercury, and selenium
Attribute table details     Download



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Detailed Metadata


  • Dataset Creator(s)
    • Name: Dr. Valeria Paz 
    • Position: Courtesy Post Doctoral Researcher
    • Organization: Florida International University
    • Email: vpaz003@fiu.edu

    • Name: Dr. Michael Heithaus 
    • Position: Dean School of Arts and Sciences
    • Organization: Florida International University
    • Email: heithaus@fiu.edu

    • Name: Dr. Jeremy  Kiszka  
    • Position: Assistant Professor
    • Organization: Florida International University
    • Email: jkiszka@fiu.edu

    • Name: Kirk Gastrich 
    • Position: Lab manager and researcher
    • Email: kgastric@fiu.edu

  • Dataset Abstract
    Cetaceans can feed at upper trophic levels and occur from freshwater to open-ocean ecosystems. Due to their abundance, mobility, and high metabolic rates, they have the potential to affect the structure and function of ecosystems through both top-down and bottom-up pathways. To better understand what ecological roles they may play in a system, it is important to understand patterns and drivers of their abundance, habitat use, and trophic interactions. I investigated the trophic interactions and pollutant exposure of common bottlenose dolphins (Tursiops truncatus) of the Florida Coastal Everglades. Based on bulk stable isotope analysis of tissue samples collected using biopsy sampling, it appears that despite their high mobility, bottlenose dolphins restrict their foraging within the habitats where they were sampled. Trophic position and foraging locations affected exposure to pollutants, with high levels of mercury found in dolphins estimated to forage at higher trophic levels and feeding within an inland bay. Mercury levels also varied with age and sex. Dolphins and their prey both contained substantial mercury levels and dolphins’ health could be impacted by this exposure, but the selenium levels we measured might counteract these negative effects.
  • Geographic Coverage
    Bounding Coordinates
    Florida Coastal Everglades
    N: 25.2600055, S: 25.2071794, E: -80.8018979, W: -81.0707961

  • Attributes
    • Data Table:   Bottlenose Dolphin Biopsy data- Isotopes, age, total mercury and selenium
      Attribute Name:
      Date
      Attribute Label:
      Date
      Attribute Definition:
      Date
      Storage Type:
      dateTime
      Measurement Scale:
      Missing Value Code:
       

      Attribute Name:
      Sample_ID
      Attribute Label:
      Sample_ID
      Attribute Definition:
      Sample ID name
      Storage Type:
      string
      Measurement Scale:
      text
      Missing Value Code:
       

      Attribute Name:
      Location
      Attribute Label:
      Location
      Attribute Definition:
      Location area of biopsy sample
      Storage Type:
      string
      Measurement Scale:
      Florida Bay= Florida Bay sample location
      Gulf of Mexico= Gulf of Mexico sampling location
      Shark River= Shark River sampling location
      Tarpon Bay= Tarpon Bay sampling location
      Whitewater Bay= Tarpon Bay sampling location
      Missing Value Code:
       

      Attribute Name:
      Season
      Attribute Label:
      Season
      Attribute Definition:
      season of time of the sampling event - wet or dry
      Storage Type:
      string
      Measurement Scale:
      Dry= Dry season- November to May
      Wet= Wet season- June to October
      Missing Value Code:
       

      Attribute Name:
      Blubber_Delta15N
      Attribute Label:
      Blubber_Delta15N
      Attribute Definition:
      Nitrogen Stable isotope of blubber tissue
      Storage Type:
      float
      Measurement Scale:
      Units: permil
      Number Type: real
      Missing Value Code:
      -9999 ( No sample available for analysis)

      Attribute Name:
      Blubber_Delta13C
      Attribute Label:
      Blubber_Delta13C
      Attribute Definition:
      Carbon Stable isotope of blubber tissue
      Storage Type:
      float
      Measurement Scale:
      Units: permil
      Number Type: real
      Missing Value Code:
      -9999 ( No sample available for analysis)

      Attribute Name:
      Skin_Delta15N
      Attribute Label:
      Skin_Delta15N
      Attribute Definition:
      Nitrogen Stable isotope of skin tissue
      Storage Type:
      float
      Measurement Scale:
      Units: permil
      Number Type: real
      Missing Value Code:
       

      Attribute Name:
      Skin_Delta13C
      Attribute Label:
      Skin_Delta13C
      Attribute Definition:
      Carbon Stable isotope of skin tissue
      Storage Type:
      float
      Measurement Scale:
      Units: permil
      Number Type: real
      Missing Value Code:
       

      Attribute Name:
      Latitude_DD
      Attribute Label:
      Latitude_DD
      Attribute Definition:
      Latitude
      Storage Type:
      float
      Measurement Scale:
      Units: Decimal Degrees
      Number Type: real
      Missing Value Code:
       

      Attribute Name:
      Longitude_DD
      Attribute Label:
      Longitude_DD
      Attribute Definition:
      Longitude
      Storage Type:
      float
      Measurement Scale:
      Units: Decimal Degrees
      Number Type: real
      Missing Value Code:
       

      Attribute Name:
      Sex
      Attribute Label:
      Sex
      Attribute Definition:
      Sex of individual sampled
      Storage Type:
      string
      Measurement Scale:
      F= Female
      M= Male
      Missing Value Code:
       

      Attribute Name:
      Age
      Attribute Label:
      Age
      Attribute Definition:
      Average estimated age
      Storage Type:
      float
      Measurement Scale:
      Units: Age unit
      Number Type: real
      Missing Value Code:
      -9999 ( No sample available for analysis)

      Attribute Name:
      low_age
      Attribute Label:
      low_age
      Attribute Definition:
      Low range of estimated range
      Storage Type:
      float
      Measurement Scale:
      Units: Age unit
      Number Type: real
      Missing Value Code:
      -9999 ( No sample available for analysis)

      Attribute Name:
      high_age
      Attribute Label:
      high_age
      Attribute Definition:
      High range of estimated age
      Storage Type:
      float
      Measurement Scale:
      Units: Age unit
      Number Type: real
      Missing Value Code:
      -9999 ( No sample available for analysis)

      Attribute Name:
      ppm_THg
      Attribute Label:
      ppm_THg
      Attribute Definition:
      Total Mercury ppm
      Storage Type:
      float
      Measurement Scale:
      Units: ppm
      Number Type: real
      Missing Value Code:
      -9999 ( No sample available for analysis)

      Attribute Name:
      THg_molar
      Attribute Label:
      THg_molar
      Attribute Definition:
      Total Mercury molar weight
      Storage Type:
      float
      Measurement Scale:
      Units: grams per mole
      Number Type: real
      Missing Value Code:
      -9999 ( No sample available for analysis)

      Attribute Name:
      Se_ppm
      Attribute Label:
      Se_ppm
      Attribute Definition:
      Selenium ppm
      Storage Type:
      float
      Measurement Scale:
      Units: ppm
      Number Type: real
      Missing Value Code:
      -9999 ( No sample available for analysis)

      Attribute Name:
      Se_molar
      Attribute Label:
      Se_molar
      Attribute Definition:
      Selenium molar weight
      Storage Type:
      float
      Measurement Scale:
      Units: grams per mole
      Number Type: real
      Missing Value Code:
      -9999 ( No sample available for analysis)


    • Data Table:   Prey targeted by bottlenose dolphins- Isotopes, total mercury, and selenium
      Attribute Name:
      Sample ID
      Attribute Label:
      Sample ID
      Attribute Definition:
      Sample ID name
      Storage Type:
      string
      Measurement Scale:
      text
      Missing Value Code:
       

      Attribute Name:
      Date
      Attribute Label:
      Date
      Attribute Definition:
      Date
      Storage Type:
      dateTime
      Measurement Scale:
      Missing Value Code:
       

      Attribute Name:
      Gear_Type
      Attribute Label:
      Gear_Type
      Attribute Definition:
      Gear type
      Storage Type:
      string
      Measurement Scale:
      CN= Cast Net
      HL= Hook and line- fishing pole
      Missing Value Code:
       

      Attribute Name:
      Location
      Attribute Label:
      Location
      Attribute Definition:
      Location of sampling
      Storage Type:
      string
      Measurement Scale:
      Florida Bay= Florida Bay sample location
      Shark River= Shark River sampling location
      Tarpon Bay= Tarpon Bay sampling location
      Whitewater Bay= Whitewater Bay sampling location
      Missing Value Code:
       

      Attribute Name:
      Latitude_DD
      Attribute Label:
      Latitude_DD
      Attribute Definition:
      Latitude
      Storage Type:
      float
      Measurement Scale:
      Units: Decimal Degrees
      Number Type: real
      Missing Value Code:
       

      Attribute Name:
      Longitude_DD
      Attribute Label:
      Longitude_DD
      Attribute Definition:
      Longitude Decimal Degrees
      Storage Type:
      float
      Measurement Scale:
      Units: Decimal Degrees
      Number Type: real
      Missing Value Code:
       

      Attribute Name:
      Species
      Attribute Label:
      Species
      Attribute Definition:
      Species
      Storage Type:
      string
      Measurement Scale:
      Caranx sp.= Caranx sp.
      C. nebulosus = Cynoscion nebulosus
      C. undecimalis= Centropomus undecimalis
      Caranx sp.= Caranx sp.
      E. saurus= Elops saurus
      L. griseus= Lutjanus griseus
      L. rhomboides= Lagodon rhomboides
      M. cephalus= Mugil cephalus
      S. ocellatus= Sciaenops ocellatus
      Missing Value Code:
       

      Attribute Name:
      Muscle_Delta15N
      Attribute Label:
      Muscle_Delta15N
      Attribute Definition:
      Nitrogen Stable isotope of muscle tissue
      Storage Type:
      float
      Measurement Scale:
      Units: permil
      Number Type: real
      Missing Value Code:
       

      Attribute Name:
      Muscle_Delta13C
      Attribute Label:
      Muscle_Delta13C
      Attribute Definition:
      Carbon Stable isotope of muscle tissue
      Storage Type:
      float
      Measurement Scale:
      Units: permil
      Number Type: real
      Missing Value Code:
       

      Attribute Name:
      Total_Length_cm
      Attribute Label:
      Total_Length_cm
      Attribute Definition:
      total length
      Storage Type:
      float
      Measurement Scale:
      Units: centimeter
      Number Type: real
      Missing Value Code:
       

      Attribute Name:
      Fork_Length_cm
      Attribute Label:
      Fork_Length_cm
      Attribute Definition:
      Fork Length
      Storage Type:
      float
      Measurement Scale:
      Units: centimeter
      Number Type: real
      Missing Value Code:
      -9999 (No Fork Length )

      Attribute Name:
      Weight_kg
      Attribute Label:
      Weight_kg
      Attribute Definition:
      Weight
      Storage Type:
      float
      Measurement Scale:
      Units: kilogram
      Number Type: real
      Missing Value Code:
      -9999 (Not able to be measured)

      Attribute Name:
      THG_ppm
      Attribute Label:
      THG_ppm
      Attribute Definition:
      Total Mercury ppm
      Storage Type:
      float
      Measurement Scale:
      Units: ppm
      Number Type: real
      Missing Value Code:
       


  • Methods
    Method Step

    Description
    Stable Isotope Analysis
    Dolphin skin samples were removed from the blubber layer using a methanol-rinsed stainless-steel blade by cutting as close to the interface between the two layers as possible without retaining any blubber. Dolphin samples (both skin and blubber) and prey samples (muscle tissue) were dried in an oven at 60 °C for 24-48 hr and then homogenized into a fine powder (DeNiro and Epstein, 1978). Lipids were removed only from dolphin samples using a 2:1 chloroform:methanol mixture for one minute with a solvent volume three times greater than the sample, left undisturbed for at least 45 min, centrifuged for 10 min, and then the supernatant was removed. After repeating this process three times, each dolphin sample was rinsed in deionized water and dried. The dried prey samples and lipid-extracted dolphin samples were then weighed, (0.4–0.7 mg) , and placed in a 4x6 mm tin capsule for SIA using a ThermoFinnigan Delta V isotope ratio mass spectrometer (IRMS) coupled with a NA 1500 NE elemental analyzer. Isotopic ratios are reported in the standard delta (δ) notation relative to the international standards of Vienna Pee Dee belemnite (δ13C) and atmospheric nitrogen (δ15N) using the following equation (1):
    (1) δ(‰) = [(RSample/RStandard) – 1] x 1000
    All stable isotope analyses (SIA) were completed at the Southeast Environmental Research Center Stable Isotope Laboratory at Florida International University. Analytical reproducibility was based on replicates of internal standards including bovine liver and glycine; variation among standards was 0.12‰ and 0.10‰ for δ13C and δ15N, respectively. The mean skin and blubber C: N ratios were less than 3, indicating an adequate lipid extraction (Lesage et al., 2010).

    References:
    DeNiro, M. J., & Epstein, S. (1978). Influence of diet on the distribution of carbon isotopes in animals. Geochimica et cosmochimica acta, 42(5), 495-506.

    Lesage, A., Lelli, M., Gajan, D., Caporini, M. A., Vitzthum, V., Miéville, P., ... & Emsley, L. (2010). Surface enhanced NMR spectroscopy by dynamic nuclear polarization. Journal of the American Chemical Society, 132(44), 15459-15461.


    Method Step

    Description
    DNA extraction and sex identification
    In order to sex sampled individual dolphins, DNA was extracted from skin tissue (< 2 mm) using a modified phenol/chloroform protocol from Sambrook et al. (1989) and described in detail in Beal et al. (2019). Concentrations of extracted DNA were checked by nanodrop and quality checked by gel electrophoresis. Aliquots at 30 ng/µL concentration were created for sex and age analysis procedures. Sex was identified by PCR and gel electrophoresis using the following PCR protocol: 10 µL H2O, 0.2 µL Thermo ScientificTM DreamTaqTM (5 U/ µL), 4 µL DreamTaq Polymerase Buffer, 1 µL dNTPs (2mM), 1 µL MgCl2 (25mM), 1 µL of Forward and Reverse ZFX primers (1 µM) and Forward SRY primer, and 0.5 µL Reverse SRY primer (1 µM) to which 1.5 µL of aliquoted DNA was added for a total volume of 21.2 µL for each sample. Thermocycler settings were as follows: initial denaturation of 95°C for 30s, followed by 30 cycles of 94°C for 30s, 51°C for 45s, and 72°C for 45s, then a final extension at 68°C for 5 min, ending with a final hold at 4°C. PCR products were run on a 2.5% agarose gel with Smart Glow pre-stain at 90 Voltz for approximately 1.5 hours and viewed with UV light.

    References:
    Beal, A. P., Kiszka, J. J., Wells, R. S., & Eirin-Lopez, J. M. (2019). The bottlenose dolphin epigenetic aging tool (BEAT): A molecular age estimation tool for small cetaceans. Frontiers in Marine Science, 6, 561.

    Sambrook, J., Fritsch, E. F., & Maniatis, T. (1989). Molecular cloning: a laboratory manual (No. Ed. 2). Cold spring harbor laboratory press.


    Method Step

    Description
    Age was estimated for all individuals using the Bottlenose Epigenetic Aging Tool (BEAT; Beal et al. 2019). Extracted DNA was divided into 600 ng aliquots (20ng/µL) and subjected to bisulfite transformation and pyrosequencing using the established protocol for the BEAT (EpigenDx, Hopkinton, MA, USA). The % DNA methylation was used in the BEAT model equation (2) to estimate age for all individuals. The BEAT model was determined to have a root mean square error of 5.14 when cross validated using the leave one out cross validation (LOOCV) method. This means that individual age estimates produced by the BEAT model are within this error range (Beal et al., 2019). Using this potential error, both high and low age estimates were also used in analyses. High age estimates were used for this study.
    (2) Age estimate= 8.602 + 4.392 (%DNA GRIA_5) – 1.149 (%DNA TET2_2)

    References:
    Beal, A. P., Kiszka, J. J., Wells, R. S., & Eirin-Lopez, J. M. (2019). The bottlenose dolphin epigenetic aging tool (BEAT): A molecular age estimation tool for small cetaceans. Frontiers in Marine Science, 6, 561.


  • Keywords
    biopsies, mercury, total mercury, carbon isotopes, nitrogen isotopes, aging, DNA methylation, bottlenose dolphins, fish stable isotopes, Tursiops truncatus, isotopes, stable isotopes, fishes
  • Dataset Contact
    • Name: Kirk Gastrich 
    • Position: Lab manager and researcher
    • Organization: Florida International University
    • Email: kgastric@fiu.edu

    • Name: Dr. Valeria Paz 
    • Position: Courtesy Post Doctoral Researcher
    • Organization: Florida International University
    • Email: vpaz003@fiu.edu

    • Name: Michael  Heithaus 
    • Position: Dean School of Arts and Sciences
    • Organization: Florida International University
    • Email: heithaus@fiu.edu

  • Data Table and Format
    Data Table:  Bottlenose Dolphin Biopsy data- Isotopes, age, total mercury and selenium

    Entity Name:
    2023_LTER_DolphinBiopsy
    Entity Description:
    Bottlenose Dolphin Biopsy data- Isotopes, age, total mercury and selenium
    Object Name:
    2023_LTER_Dolphin.csv
    Number of Header Lines:
    1
    Attribute Orientation:
    column
    Field Delimiter:
    ,
    Number of Records:
    90

    Data Table:  Prey targeted by bottlenose dolphins- Isotopes, total mercury, and selenium

    Entity Name:
    2023_LTER_Dolphin_Prey
    Entity Description:
    Prey targeted by bottlenose dolphins- Isotopes, total mercury, and selenium
    Object Name:
    2023_LTER_Dolphin_Prey.csv
    Number of Header Lines:
    1
    Attribute Orientation:
    column
    Field Delimiter:
    ,
    Number of Records:
    123