Abstract

An increase in the reporting of diseases in marine organisms has raised concerns that ocean health is deteriorating.^1,2 Diseases can alter marine mammal population distribution and abundance, which may precipitate species' extinctions, and regime changes within marine communities.³ However, whether the increase in reports represents a real and widespread degeneration in marine mammal health remains unclear.⁴ This uncertainty is due to a lack of information on the true incidence of marine mammal diseases and few long-term datasets, as well as a lack of data integration.³ Although marine mammals can function as ecosystem indicators, there is currently no readily accessible national or international dataset for tracking marine mammal disease trends.⁵

A review of the status of marine mammal research in 2003 concluded that a more coherent and comprehensive infrastructure was needed to investigate marine mammal health in a systematic and holistic manner.⁶ Thus, the goal of the Marine Mammal Health Map project is to develop a web-based marine mammal health and disease mapping system that will allow managers, scientists, policy makers and the public to track spatiotemporal trends in marine mammal health. This platform also will provide a centralized location for stranding network participants to disseminate their collective data. The map can be used to determine marine mammal health status relative to other components of the ocean ecosystem, and future health studies can be planned based on the information presented.

The Health Map is a collaboration among many groups, including the National Marine Fisheries Service (NMFS) Marine Mammal Health and Stranding Response Program (MMHSRP), the Marine Mammal Commission, the Integrated Ocean Observing System (IOOS), the National Wildlife Health Center, NGOs, academics and State agencies. The first objective of the Health Map was to conduct a small-scale pilot study using stranding data from California NMFS-MMHSRP stranding responders collected from 2005 to 2010. Deceased animals were assigned to a health category based on the reported cause of death. Categories included: infectious disease, biotoxin, trauma, neoplasia, malnutrition, other, or unknown. When available, more specific information about disease processes also was reported. The results were mapped and can be overlaid with oceanographic data within the region IOOS or a similar data portal, which allows for a more comprehensive examination of the factors that may be affecting marine mammal health. For example, researchers may use the map to investigate the relationship between rates of ship strikes in baleen whales and acoustic impacts, to monitor harmful algal bloom distribution and marine mammal mortality, and to track specific pathogen distribution and development of marine mammal disease. Ultimately, our goal is to create a national, and eventually a global, map to improve assessments of ocean health.

Acknowledgements

The authors wish to acknowledge those people that contributed to the development and implementation of the concept, including Dr. Teri Rowles (NOAA-MMHSRP), Dr. Samantha Simmons (Marine Mammal Commission), Dr. Stephanie Venn-Watson (NMMF), Dr. Melissa Miller (CDFG), and Sarah Wilkin (NOAA-MMHSRP). The authors thank all of the staff and volunteers of the California Marine Mammal Stranding Network that work tirelessly to care for these animals and collect samples, including those used in this study.

Literature Cited

1.  Gulland FMD, Hall AJ. Is marine mammal health deteriorating? Trends in the global reporting of marine mammal disease. EcoHealth. 2007;4:135–150.

2.  Harvell D, Aronson R, Baron N, et al. The rising tide of ocean diseases: unsolved problems and research priorities. Front Ecol Environ. 2004;2:375–382.

3.  Kim K, Dobson AP, Gulland FMD. Diseases and the conservation of marine biodiversity. In: Norse EA, Crowder LB, eds. Marine Conservation Biology: The Science of Maintaining the Sea's Biodiversity. Washington, DC: Island Press; 2005: 149–166.

4.  Lafferty KD, Porter J, Ford SE. Are diseases increasing in the ocean? Annu Rev Ecol Evol Syst. 2004;35:31–54.

5.  Gulland FMD, Simmons SE, Rowles TW, Moore SE, Sleeman JM, Weiss M. Marine mammal health as an ecosystem health sentinel (White paper). Interagency Ocean Observing Committee. 2012.

6.  Reeves RR, Ragen TJ. 2004. Executive Summary in Future Directions in Marine Mammal Research. A report of the Marine Mammal Commission Consultation. August 4–7, 2003.