Bottlenose Dolphins and Coastal Health

1. Bottlenose Dolphins and Coastal Health Lori Schwacke, Ph.D. NOAA’s Cooperative Center for Marine Animal Health

2. Changes to marine environment Human impacts ↑ chemical contam. ↑ nutrient ↑ pathogens ↓ suitable habitat ↑ fishery closures ↑ health risks ↓ recreational use ↓ aesthetic value Time Stress on Coastal Ecosystems Increasing human population & coastal development Ecological impacts Altered land, ↑ impervious surface ↑ pollutants, run-off Altered waterways ↑ fishing pressure Loss of species Altered food webs ↑ algal blooms Disease/mortality of indicator species

3. Bottlenose Dolphin (Tursiops truncatus)

4. U.S. Coastal Distribution

5. Why Study Dolphin Health? • Dolphins are sentinels for coastal ecosystems: • Dolphin health reflects availability/quality of prey & habitat; reflects stressors in environment • Chemical pollutants • Biotoxins • Pathogens • Increasing reports of dolphin disease and mortality raises concern about deteriorating ocean health • Environmental stressors affecting dolphins can also affect humans

6. Trace metals Pharmaceuticals Perflourinated chemicals (many consumer products) Persistent organic pollutants (POPs) Chlorinated pesticides (DDT, chlordanes) Polychorinated biphenyls (PCBs) Brominated flame retardants Chemical Contaminants • Wash from land into estuaries via run-off from urban areas, industrial sites or agricultural fields • Settle into sediments, enter into food chain when they are consumed by bottom-feeding (detrivore) organisms or absorbed by fish gills

7. Coastal Food Web 3° consumers (trout) detrivores (shrimp, mullet) 2° consumers (menhaden, juv. fishes such as red drum, croaker) zooplankton Organic debris, benthic microalgae primary producers (phytoplankton)

8. Organic debris Biomagnification of Persistent Contaminants (e.g. PCBs) Dolphins are top level predators, vulnerable to biomagnification Dolphins ~10-100 ppm Large fish 2-8 ppm Small fish 0.2-2 ppm Plankton 0.04 ppm

9. Bioaccumulation of PCBs Dolphins are long-lived and have lipid-rich blubber, so vulnerable to bioaccumulation Figure from Wells et al. 2005, Science of the Total Environment

10. Biotoxins • Biotoxins are produced by certain species of phytoplankton • Change in environment may cause dramatic increase in phytoplankton (bloom) • Bloom of toxin-producing algae referred to as Harmful Algal Bloom (HAB) • Cause fish-kills, intoxicate seafood

11. Source: www.whoi.edu Brevetoxin • Florida “red-tide” • Neurotoxin shellfish poisoning, respiratory distress

12. 0 Cells 1-104 Cells 104 -105 Cells 105 -106 Cells >106 Cells Panhandle Mortality Events K. brevis cell count data Dolphin stranding • 152 dolphins stranded, Aug.1999 – May 2000 • 107 dolphins stranded, Mar. – Apr. 2004, no observed bloom • 93 dolphins stranded, Sep. 2005 – Apr. 2006

13. Brevetoxin Related Dolphin Mortality Events Alabama Mississippi Louisiana Texas 1999-2000 (152) 2004 (107) 2005-2006 (93) Florida 2005-2006 (~200) Multi-species 1946-1947 Gulf of Mexico

14. Unique exposure pathway/vector? Secondary stressor? Organic debris Why are dolphins in the Florida Panhandle dying? * * * *reported in Hall et al. 2007, Fair et al. 2006, Goldstein et al. 2006

15. Viral disease Morbillivirus Encephalopathies (titers to equine encephalitis) Bacterial pathogens Brucella, Leptospira Protozoal parasites Giardia, Cryptosporidium, Toxoplasma Fungal disease Lobomycosis, Aspergillosis Giardia Brucella Leptospira Infectious Disease/Pathogens Zoonotic pathogen – infectious agent that can affect both dolphins and humans

16. Summary Dolphins are sentinels of coastal health • Chemical contaminants • Top-level predator, vulnerable to biomagnification • Indicator of bioavailable contaminants • Reflect local trends in contaminant concentrations • Biotoxins • Warn of biotoxins in the food chain, even when HAB is not detected; help to identify vectors for biotoxin exposure • Suggest potential for increased susceptibility, interactions with other stressors • Disease/Pathogens • Warn of zoonotic pathogens in marine environment

17. Stranding Response • Cause of death, pathology • Age, reproductive biology, diet Photo-ID Studies • Distribution, population abundance, behavior • Mortality/reproductive events Photo: Eric Zolman Sampling Methods Remote Dart Biopsy • Contaminants, genetics, fatty acid/stable isotope Capture-Release • Physical exam, age, telemetry • Health parameters – CBC, serology, immune suite, urinalysis, biotoxin exposure, etc.

18. The End

19. Acknowledgments • NOAA Marine Mammal Health and Stranding Response Program (Panhandle dolphin health assessment project) • NMFS Southeast Fisheries Science Center, Southeast Marine Mammal Stranding Network (Panhandle dolphin stranding data) • Florida Fish and Wildlife Research Institute (K. brevis cell count data)

20. Microrray Picture? Microrray Picture? Microrray Picture? Microrray Picture? Microrray Picture? Dolphin Microarray • Expressed Sequence Tags (ESTs) isolated from dolphin peripheral blood leukocytes • Focused on stress response and immune function genes Blood samples are also used to look at gene expression and compare the patterns of expression between dolphins sampled under various environmental conditions. Scientists hope that such changes in gene expression can eventually be used to diagnose early signs of stress or disease and provide an early warning of emerging environmental problems. Blood samples are also used to look at gene expression and compare the patterns of expression between dolphins sampled under various environmental conditions. Scientists hope that such changes in gene expression can eventually be used to diagnose early signs of stress or disease and provide an early warning of emerging environmental problems. Blood samples are also used to look at gene expression and compare the patterns of expression between dolphins sampled under various environmental conditions. Scientists hope that such changes in gene expression can eventually be used to diagnose early signs of stress or disease and provide an early warning of emerging environmental problems. Blood samples are also used to look at gene expression and compare the patterns of expression between dolphins sampled under various environmental conditions. Scientists hope that such changes in gene expression can eventually be used to diagnose early signs of stress or disease and provide an early warning of emerging environmental problems.