Chapter V — Marine Mammal Strandings and Die-Offs 



established to assist in developing and implementing 

 a national die-off response plan. In advance of the 

 meeting, the Service organized and held a workshop 

 in Galveston, Texas, to field test the draft necropsy 

 and tissue sampling protocols developed by the group 

 following its meeting in December 1990. The results 

 of this workshop were discussed and used at the 8 

 April meeting to revise and agree on a tentative 

 schedule for completing standard protocols for collect- 

 ing life history information, conducting necropsies, 

 and collecting samples from dead stranded marine 

 mammals. 



At the April meeting, the group also developed a 

 set of agreed criteria for determining when a mortality 

 event is sufficiently unusual to merit special investiga- 

 tion. The criteria are: 



• the number of animals stranding is substantially 

 higher than would be expected from prior strand- 

 ing records; 



• animals are stranding at a time of the year when 

 strandings generally are unusual; 



• strandings are occurring in a localized area (possi- 

 bly suggesting a localized problem), are occurring 

 throughout the species' geographic range, or are 

 spreading over a larger geographic range (suggest- 

 ing spread of an infectious disease) as time passes; 



• the age or sex composition of the stranded animals 

 is different than that of animals that normally 

 strand in the area; and 



• the general physical condition (e.g., weight) of 

 stranded animals is different than that seen normal- 

 ly, or the animals have unusual lesions. 



A sixth and more or less independent criterion 

 would be mortalities involving highly endangered 

 species. For example, stranding of only two or three 

 highly endangered right whales for reasons not 

 apparant (such as entanglement or ship collisions) 

 would merit immediate investigation. 



Development of a National 

 Marine Mammal Tissue Bank 



During investigation of the 1987-1988 die-off of 

 bottlenose dolphins along the U.S. mid-Atlantic coast, 

 it became clear that there were inadequate baseline 

 data and no source of tissues that could be analyzed to 

 determine pre-existing levels of anthropogenic contam- 

 inants and natural biotoxins present in the population 

 prior to the die-off. As a first step in avoiding this 

 problem in the future, the National Marine Fisheries 

 Service initiated steps in 1989 to establish a National 

 Marine Mammal Tissue Bank. Many of the protocols 

 being used to collect, prepare, and store tissue sam- 

 ples are derived from a program begun by the Miner- 

 als Management Service in 1984 to obtain and curate 

 tissue samples from walruses and other marine mam- 

 mals taken by Alaska Natives for subsistence. 



Recognizing that the value of the Tissue Bank 

 would depend on the number, types, and quality of 

 tissues being maintained, the National Marine Fisher- 

 ies Service established a Group of Experts to oversee 

 development of the bank. This group, which includes 

 a Commission representative, has met at least once 

 each year since 1989. In response to recommenda- 

 tions made by the group, the National Marine Fisher- 

 ies Service has: (1) established basic protocols for 

 collecting, preparing, storing, and accessing tissue 

 samples; (2) conducted a pilot program to test the 

 protocols; and (3) initiated studies to determine 

 whether the levels of various contaminants present in 

 tissues vary with time or the part of the body from 

 which the tissue samples are taken. 



Proposed Legislation 



As noted above, difficulties and uncertainties 

 encountered during investigation of the bottlenose 

 dolphin die-off along the mid-Atlantic coast in 1987 

 and early 1988 caused the Commission to initiate 

 efforts to develop a National Die-off Response Plan. 

 Also, as noted above, they caused the National Marine 

 Fisheries Service to initiate development of the 

 National Marine Mammal Tissue Bank, improve 

 operation of the Regional Stranding Networks, and 

 take other steps to be better prepared to respond to 

 such unusual mortality events in the future. They also 



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