Marine Mammal Stranding Networks in the 21st Century: Whence and Whither?

Marine mammals stranded ashore have captured human attention for centuries—Aristotle observed over 2000 years ago that dolphins sometimes came ashore for unknown reasons. Indigenous coastal communities from New Zealand to the Arctic have oral histories documenting stranding events (Marsh et al. 2022) and dramatic scenes of dead whales swarmed over by a curious public were recorded by 16th-century Dutch painters (Figure 1). The efforts of visionaries who saw the scientific potential in marine mammals stranded ashore have changed these events from spectacles to sites of scientific endeavor, providing the foundation for ocean biomonitoring programs worldwide. Stranded marine mammals have become recognized as sentinels for the health of conspecifics, their environment, and humans who depend on healthy ocean resources (Reddy et al. 2001). Continued investment in stranding network capacity could further enhance responses to both live and dead stranded animals, improving their welfare, expanding the science of these species, and better informing the “One Health” (an integrated, unifying approach that aims to optimize the health of people, animals, and ecosystem recognizing they are closely linked and inter-dependent) community and management actions for conservation.

Formal stranding network responses in the United States date back to 1883 (True 1883) when Frederick W. True (Marine Mammal Curator) and Spencer Fullerton Baird (Director) from the US National Museum of Natural History requested the Light Keepers of Cape Hatteras, NC, record data on marine mammal carcasses. In the United Kingdom, a 1913 agreement between the British Museum and Board of Trade recorded data on cetacean strandings by the “Receivers of Wreck” using a specific form transmitted to the museum by telegram (Fraser 1934). In 1968, New Zealand stranding data held in museums and private records were compiled by Gaskin (1968) to investigate potential causes of mass strandings (see Table 1 for a timeline of stranding network development). In the United States, Dr. James Mead and Mr. Charles Potter began their tenures at the Smithsonian Institution National Museum of Natural History in 1972, when they established the Stranding Event Alert Network “SEAN,” and distributed brochures to ocean users requesting notification of cetacean carcasses discovered along the eastern seaboard from South Carolina to Massachusetts. These activities coincided with the passing of the Marine Mammal Protection Act of 1972 (MMPA) and were the impetus for the first US Marine Mammal Commission workshop on strandings in 1977. The workshop recommended development of regional stranding networks (Geraci and St. Aubin 1979). Over the following 20 years, regional stranding networks were also established in Europe, Asia, New Zealand, Canada, and Central and South America. The morbillivirus epizootics of 1987–1988 that caused strandings of thousands of seals in the United Kingdom and Europe and bottlenose dolphins (Tursiops spp.) along the east coast of the US-motivated governments to respond to strandings in these countries. A few years thereafter federal government-coordinated stranding networks were established in England and Wales in 1990, Scotland in 1992 and the United States in 1994.

Over the half century since the passing of the MMPA in 1972 and the international moratorium on commercial whaling in 1982, the responses to stranded marine mammals have advanced. The desire to improve the welfare of live animals ashore, as well as to maximize the science obtained from these animals, led to the publication in 1993 of the first globally recognized manual on how to respond to a stranded animal (Geraci and Lounsbury 1993, revised in 2005). To enhance coordination among responders, regional, national, and international networks have further developed (reviewed by Wilkinson and Worthy 1999; Simeone and Moore 2018). These networks are typically volunteer-led, with varying amounts of government, academic, and private support. A live dolphin ashore is no longer assumed to die, and sea otters, manatees, and pinnipeds have reproduced in the wild after release from rehabilitation (Newman et al. 2003; Yu et al. 2009; Wells et al. 2013; Adimey et al. 2016; Sharp et al. 2016; Neves et al. 2020). Stranding responders have been the drivers of improving marine mammal welfare globally.

The authors declare no conflicts of interest.