Premium
FATAL SHARK ATTACK ON A HAWAIIAN MONK SEAL ( MONACHUS SCHAUINSLANDI )
Author(s) -
Alcorn Doris J.,
Kam Alan K. H.
Publication year - 1986
Publication title -
marine mammal science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.723
H-Index - 78
eISSN - 1748-7692
pISSN - 0824-0469
DOI - 10.1111/j.1748-7692.1986.tb00140.x
Subject(s) - marine fisheries , fishery , service (business) , fisheries science , geography , library science , fishing , history , fisheries management , business , biology , computer science , marketing
W e describe here a fatal attack on a Hawaiian monk seal, Monachus schauinsIandi, apparently initiated by tiger sharks, Galeocerdo cuvier. The attack occurred near sunset at 1957 h on 28 May 1982, 15 m off the landing beach on the west side of Laysan Island (25"42'N, 171"44'W), Northwestern Hawaiian Islands. Observations were made from shore at a distance of approximately 33 m. Predation by sharks on this endangered species is indicated by the presence of monk seal remains in tiger sharks (Taylor and Naftel 1978), tiger sharks seen feeding on dead seals (Balats and Whittow 1979, Johanos and Kam 1986), a tiger shark seen injuring a seal Uohanos, unpubl. ms.) and apparent shark-inflicted wounds on monk seals (e.g., Wirtt 1968, Kenyon 1973, Johnson and Johnson 1978, Alcorn 1984), but a fatal attack on a live monk seal has not been documented. First attack-At 1929 h the fins of a large tiger shark were seen about 12 m offshore, near two monk seals. One seal, an adult, appeared by its behavior to be a male; the other seal was the site of a subadult with open pink puncture wounds on its back and sides and shallow tears as long as 8 cm. The wounds were not bleeding and were at least a few days old; we had seen them on this seal 3 d earlier. At that time, the subadult was tentatively identified as a female, based on behavioral responses to an approaching adult male. The wounds were not caused by a shark but were the type inflicted by adult male seals during mating attempts (Johnson and Johnson 1978, E. Shallenberger pers. comm.). Such injuries occur most frequently on adult and subadult females and at geographic locations where adult male seals outnumber adult females.