Notes

MARINE MAMMAL SCIENCE, 2(1):70-72 (January 1986) 0 1986 by the Society for Marine Mammalogy

THE CARIBBEAN MONK SEAL IS EXTINCT

In 1973 Kenyon (1977) conducted an aerial search for Caribbean monk seals, Monachus tropicalis, in areas in the Gulf of Mexico and Caribbean where Rice (1973) suggested that the last survivors might exist. The survey covered 6,377 km and included islands and atolls off Campeche, Yucatan, Quintana Roo (Mexico), Belize, Honduras, Nicaragua and the central Caribbean to Ja- maica. No monk seals or evidence of their presence was found. However, fishermen were observed in many habitats considered suitable for seals. Because few seal populations thrive in close proximity to humans, Kenyon concluded that, even if a few seals were still living, there was no hope that the species could recover. From 13-25 April 1980, Sergeant et al. (1980) saw no seals or evidence of them on several sandy islands in the southeastern Bahamas between the Dominican Republic and Nassau. We present additional evidence that Caribbean monk seals are extinct, based on visits to islands and waters where they were last seen and (judging from the historical record) were most likely to have survived. On these remote islands we searched for seals and their tracks, skeletal remains, carcasses and scats. We interviewed lighthouse keepers and fishermen. From 5-15 September 1984, we cruised south from BeRwick, Louisiana, across the Gulf of Mexico to Cam- peche, Mexico, aboard the Scripps Institution of Oceanography research vessel, Robert G. Sproul (Fig. 1). During all daylight hours when the ship was under- way, observers searched the waters for seals from the bridge, 7.5 m above the water line. We went ashore at three island groups off the north coast of the Yucatan Peninsula: Islas Triangulos, Cayo Arenas and Arrecife Alacran. Another island, Cayo Arcas, was visited by helicopter on 7 September. We saw no seals or evidence of their existence in the places we visited. The lighthouse keepers living year around on Triangulo Oeste, Cayo Arenas, Isla Perez (Arrecife Alacran) and Cayo Arcas reported seeing no seals during their tenure and that of their predecessors covering the past 10 yr or more. On neighboring islands, islets and keys, such as Triangulo Este and Isla Desterrada (Arrecife Alacran), there were signs of frequent human visits, including foot- prints, campsites, remains of slaughtered turtles (Chelonia mydas, Caretta caret- ta, Eretmochelys imbricata), ravaged turtle nests, shark kills (Sphyrna mokarran, Ginglymostoma cirratum) and butchering sites, and hundreds of queen conch

70 NOTES 71

LOUISIANA

BAHIA DE CAMPECHE

Figure 1. Track of the Robert G. Sproul in 1984 (straight line) and helicopter flight to Cayo Arcas (dotted line). Key: 0) Cayo Arcas; 1) Berwick, Louisiana; 2) Triangulo Oeste; 3) Campeche; 4) Triangulo Este; 5) Cayo Arenas; 6) Ma Desterrada (Arrecife Alacran); 7) Isla Perez (Arrecife Alacran); 8) Isla Contoy; 9) Isla Cozumel; 10) Xcalak; 11) Banco Chinchorro. shells, Strombus gigas, whose contents had been removed by fishermen. We were informed that spiny lobsters, Panulirus argus, are fished regularly on these islands and reefs from March to December. All pinnipeds inhabiting temperate waters appear on land or sand bars during the yeat to rest, give birth or nurse their young. No species is completely aquatic. Based on the absence of seals and the evidence of frequent or regular human activity on these Mexican islands, given the ubiquity of humans in other parts of the animal’s former range (e.g., islands in the Caribbean), and considering the incompatibility of these pinnipeds and fishermen-the primary human occupants of these islands- we conclude that the Caribbean monk seal is ex- 72 MARINE MAMMAL SCIENCE, VOL. 2, NO. 1, 1986

tinct. We endorse a proposal by the National Marine Fisheries Service to remove it from the Endangered Species list and officially recognize its extinction (Federal Register, 1984, 49:44774-44775).

ACKNOWLEDGMENTS

We thank Dra. E. Polanco Jaime and other Mexican authorities for providing ship clearance in Mexican waters on short notice, Petroleos Mexicanos for transportation to Cayo Arcas, and G. Shor and the staff at Scripps Institution of Oceanography for use of the research vessel. This work was supported in part by NSF grant BNS 74-01363 402.

LITERATURECITED

KENYON,K. W. 1977. Caribbean monk seal extinct. Journal of Mammalogy 58: 97-98. RICE,D. W. 1973. Caribbean monk seal (Monachus tropicalis). Pages 98-112 in Seals, Proceedings of a working meeting of seal specialists on threatened and de- pleted seals of the world, held under the auspices of the Survival Service Commission of the IUCN, 18-19 August 1972, at the University of Guelph, Ontario, Canada, IUCN publ. New Series, Supp. Paper, Morges, Switzerland 39:1-176. SERGEANT, D., G. NICHOLS AND D. CAMPBELL. 1980. Expedition of R/V Regina Maris to search for Caribbean Monk Seals in the South East Bahamas Islands, April 13- 26, 1980. Pages 41-44 in K. Ronald, ed. Newsletter of the League for the Conservation of the Monk Seal, no. 5.

BURNEYJ. LEBOEUF Received: February 27, 1985 Department of Biology, Accepted: August 14, 1985 University of California, Santa Cruz, California 95064 KARL W. KENYON 11990 Lakeside Place, N.E., Seattle, Washington 98123 BERNARDO VILLA-RAMIREZ Juan Pablo Gallo Reynoso, Instituto de Biologia, U.N.A.M., Laboratorio de Mastotoologia, Apdo. Postal 70-153, Mexico D.F., C.P. 04510