in California. Consequently, the Service cannot authorize 

 any incidental take and any fisherman who may take harbor 

 porpoise incidentally during fishing operations in central 

 California may be subject to prosecution under the Marine 

 Mammal Protection Act. However, the legislation enacted by 

 the State of California may be sufficient to avoid or substan- 

 tially reduce incidental take in the future. The Commission 

 looks forward in 1988 to further consultations with the National 

 Marine Fisheries Service and the California Department of 

 Fish and Game to determine if additional conservation measures 

 may be required. 



Gulf of California Harbor Porpoise (Phocoena sinus) 



The Gulf of California harbor porpoise is one of the 

 smallest and rarest cetacean species. There have been few 

 confirmed sightings of live animals, and most of what is known 

 about the species has been obtained from examination of car- 

 casses washed up on beaches or taken incidentally in gill 

 nets in the upper Gulf of California, Baja California, Mexico. 

 Sighting and stranding data suggest that the species' range 

 is limited to the northern third of the Gulf. Data are insuf- 

 ficient to estimate population size. However, given the few 

 sightings, it seems unlikely that there are more than several 

 hundred animals. 



The major threat to the species appears to be incidental 

 take in the gill net fishery for totoaba f Cynoscion macdonaldi ) . 

 This fishery operated in the Gulf of California from the late 

 1940s to 1975 when it was closed due to depletion of the fish 

 stocks. In 1985, experimental fishing was conducted to assess 

 the status of the totoaba stocks and, during the fishing operat- 

 ion, at least 13 harbor porpoise were caught and killed. The 

 fishery remains closed, but the closure is difficult to enforce 

 and some illegal fishing and incidental take of harbor porpoise 

 continue to occur. 



Habitat degradation and destruction also may be affecting 

 the Gulf of California harbor porpoise. Dams and water projects 

 on the Colorado River in the southwestern United States have 

 reduced its outflow into the Gulf of California. This may 

 have reduced nutrient input and biological productivity in 

 the Gulf, including reduction of species eaten by harbor por- 

 poise. Also, exploratory drilling for oil and gas has begun 

 in the northern Gulf, raising the possibility of future develop- 

 ment, disturbance, oil spills, and other types of environmental 

 contamination. In addition, run-off from farms and roads in 

 the northern Gulf of California drainage system may be intro- 

 ducing significant quantities of pesticides and other contami- 

 nants . 



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