Abstract
Animals with gunshot injuries are regularly presented to The Marine Mammal Center (TMMC) and other marine mammal rehabilitation facilities for care and treatment.1-6 TMMC Data collected over the past 20-year period reveals an annual rate that has varied from a high of 74 individuals, 9.3% of total admitted animals in 1992 to a low of 3 individuals (0.5%) in 2006. The 20-year mean is 3.6% of total admits. California sea lions are the most commonly presented species with gunshot injury. Although both genders and all age classes are seen with these injuries, gunshot animals are more commonly male than female and the most common age class is yearling.
Evidence of gunshot injury is sometimes an incidental finding unrelated to the reason for stranding and presentation to the center. In other cases the wounds result in a variety of debilitation ranging from minor to fatal. The variation and severity of the wounds result from the interaction of a variety of ballistic factors. Tremendous kinetic energy is transferred from the weapon to the patient by the projectiles. In addition to the energy transferred, projectile fragmentation and deformation, yaw, temporary cavity formation, and the tissue type impacted are major influences on outcome.7 Lead toxicosis may develop from retained projectiles particularly if they lodge in a joint cavity.8 Although intoxication has been seen at TMMC from ingested lead, toxicosis from projectiles remaining in soft tissues has not been recognized.9
Wounds, projectiles, and fragments observed during evaluation of these patients suggest all of the three most common types of small arm firearms (handguns, rifles, and shotguns) have been used to deliberately injury marine mammals. Prosecution of individuals responsible for these injuries is challenging. An accurate and thorough forensic assessment of the injuries, complete record keeping and documentation, and proper chain-of-custody handling of materials that may be used as evidence is important.8 These cases may develop significant public interest and a media following.
Animals that survive the initial wounds may suffer debilitation that results in a determination they are not releasable back to the wild. Federally approved facilities may receive collection animals that have previously been gunshot. Understanding how and why these injuries occur and the potential impact on the health and welfare of the animals is useful when managing their care and the messaging associated with them.
Acknowledgements
We thank Ms. Erin Brodie and the entire Stranding Department of TMMC for compiling data.
References
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