abstract
Disposal of marine mammal carcasses can prove challenging particularly for large whales, mass whale and dolphin strandings or during mass mortalities. These challenges can be logistical and or biological, but all, in some way relate to human health, safety and issues of bio-security. The size or number of animals, carcass condition, logistics and potential hazards including high tissue levels of persistent pollutants, drug residues from treatment or euthanasia, as well as pathogens and real or suspected zoonotic agents further complicate matters. In the past, options for disposal have included leaving or burial on site or removal and translocation for incineration, rendering or sinking at sea. All disposal options have drawbacks and advantages and no single solution has emerged as ideal. However, increasing concerns for safety, and environmental impact as well as an increase in responses to unusual and mass mortalities creates a need for development and improvement of disposal options. The University of New England Marine Animal Rehabilitation Center in Biddeford Maine has built a facility to test and develop composting as a disposal option for marine mammal carcasses.
Geraci and Lounsbury note, "The simplest way for a carcass to disappear is to turn your back on it and walk away".1 Unfortunately, options for disposal of animal carcasses of all types (wildlife, poultry and livestock) are generally becoming more limited, costly, and complex due to closure of rendering plants, landfill restrictions or availability, as well as the impracticality and expense of incineration and other technologies. Concerns about bio-security particularly following disease outbreaks and natural disasters contribute to this dilemma. Rendering, incineration, landfill burial and other forms of disposal have the disadvantage that waste must be transported to a central disposal point. Transport can raise a logistical concern for bio-security, particularly when dealing with exotic species and unknown (or emerging) diseases. Although other emerging disposal technology (such as alkaline digestion) can address the biological problems, the equipment required for these processes remains expensive and few facilities--beyond experimental agricultural or research veterinary facilities--are available. Furthermore, even if a facility is available, the problem of transporting carcasses some distance to a central facility persists.
For the most part these problems and concerns are similar for livestock and for marine mammals. Transporting of animals to a central area for disposal--either by incineration, rendering or other methods increases the risk of cross contamination when carcasses are moved to a central location. During the European foot and mouth epidemic of 2001 this was of particular concern as carcasses were picked up and moved from locations where disease was found, through locations that were disease free. In response, the agricultural community sought to contain mortalities by developing techniques such as composting that could be used on site, and do not necessitate transporting carcasses long distances. In the U.S. federal and several state agencies have created emergency plans for responding to disease outbreaks and mass livestock mortalities using composting as a disposal option.
During the summer of 2007, the University of New England (UNE) Marine Animal Rehabilitation Center (MARC) constructed a test facility to compost marine mammal carcasses brought to the campus for examination. In the fall of that year UNE in conjunction with the Maine Composting School and the Maine Agricultural Cooperative Extension began a marine mammal composting field trial. Facility and field trials are underway to test composting as a disposal option and to determine the fate of contaminating compounds including sodium pentobarbital euthanasia solution. Results from temperature logging and compositional analysis show that when properly constructed these compost piles produce bacterialcidal temperatures and are likely to produce an end product with a composition consistent with conventional compost.
acknowledgments
This work was supported by a grant from the John H. Prescott Marine Mammal Rescue Assistance Grant Program, Award Number NA06NMF4390151.
References
1. Geraci J R, VJ Lounsbury. 1993. Marine Mammals Ashore: A Field Guide for Strandings, by (©1993 Texas A&M University Sea Grant College Program, ISBN 1-883550-01-7).