Chapter III — Species of Special Concern 
The brevetoxin is postulated to have made the animals 
susceptible to a number of bacterial and viral patho- 
gens that ultimately killed them. 
The National Marine Fisheries Service estimated 
that the 1987-1988 mass mortality may have reduced 
the mid-Atlantic coastal migratory stock of bottlenose 
dolphins by as much as 60 percent. On 11 November 
1988, the Center for Marine Conservation petitioned 
the Service to list the affected mid-Atlantic coastal 
migratory population of bottlenose dolphins as deplet- 
ed under the Marine Mammal Protection Act. The 
Service published an advance notice of proposed 
rulemaking and a request for comments on the propos- 
al on 11 October 1989. In a21 December 1989 letter 
to the Service, the Commission noted that the depleted 
designation probably was merited, but that it was 
based on a number of assumptions that if not validated 
would make it impossible to determine when the 
population had recovered and could be delisted. The 
Commission recommended that the Service not list the 
population as depleted without simultaneously describ- 
ing the steps that would be taken to verify the assump- 
tions upon which the designation was based and 
determine when the population no longer is depleted. 
The Commission also recommended that before 
designating the population as depleted, the Service 
develop and implement a conservation plan for 
bottlenose dolphins along the U.S. mid-Atlantic coast. 
As noted in the Commission’s previous annual 
report, on 15 August 1991 the Service published a 
Federal Register notice proposing to designate the 
mid-Atlantic coastal migratory population of bottle- 
nose dolphins as depleted under the Marine Mammal 
Protection Act. The Commission, in consultation with 
its Committee of Scientific Advisors, reviewed the 
proposal and provided comments to the Service on 4 
November 1991. The Commission noted that the 
Federal Register notice failed to address the concerns 
raised in the Commission’s 21 December 1989 letter 
regarding the proposed listing. The Commission, 
therefore, reiterated its recommendations that a 
conservation plan be developed and implemented 
before designating the population as depleted, and that 
the Service describe the steps to be taken to verify the 
assumptions on which the designation was based and 
to determine when the population was no longer 
depleted. As of the end of 1992 the Service had not 
Vi 
designated the affected population as depleted or 
developed a conservation plan to guide recovery. 
As a related matter, the Service, in its proposed 
regime to govern interactions between marine mam- 
mals and commercial fishing operations (see Chapter 
IV), classified the mid-Atlantic coastal bottlenose 
dolphin population as a Class alpha (a) stock. This 
classification is warranted under certain conditions: 
(1) if the estimated total removals from a population 
as a result of human activities are equal to or greater 
than that which can be sustained without causing the 
population to be reduced or be maintained below its 
maximum net productivity level, or (2) if the species 
or population is designated as depleted under the 
Marine Mammal Protection Act or threatened or 
endangered under the Endangered Species Act. Under 
the proposed regime, the Class a designation would 
provide that all fisheries that have significant interac- 
tions with the population may be required to carry 
observers on as much as 100 percent of their fishing 
trips in order to obtain statistically reliable informa- 
tion on the species and number of marine mammals 
taken incidentally in the fishery. This compares to a 
current requirement for 25 to 35 percent observer 
coverage. 
Gulf of Mexico and Florida 
East Coast Populations 
Bottlenose dolphins taken for research or public 
display have been taken most frequently from the Gulf 
of Mexico and the Indian River system in east-central 
Florida. As discussed in previous annual reports, 
because of uncertainties stemming from recent mass 
mortalities (see Chapter VI), in April 1989 the Marine 
Mammal Commission suspended consideration of all 
applications for permits to take bottlenose dolphins 
from the Gulf of Mexico and the east coast of Florida, 
pending an assessment of the status of the affected 
populations and the effectiveness of then-existing 
research and management programs. 
In a 16 March 1990 letter to the National Marine 
Fisheries Service, the Commission noted that the 
unusually high mortality of bottlenose dolphins that 
had been occurring in the Gulf of Mexico since 
January of that year could be caused by a contagious 
