Man Versus the Monk Seal

Abstract

Surveys of monk seals at Midway and Kure Atolls in 1957 and 1958 are compared with surveys of the same areas in 1968, 1969, and 1971. Where 68 seals were seen in 1957 and 1958 at Midway, only one seal was seen in 1968, four in 1969, and six in 1971. Before Kure was occupied by man in the early 1960's, the majority of seals used Green Island as a pupping and hauling ground. Few seals came ashore on Green Island in 1968; instead they used isolated, shifting sandspits. Observations indicate that the Kure population is declining. Evidence is presented that man's repeated disturbance of seals on beaches may increase juvenile mortality and cause seals to desert the beaches offering preferred habitat. In 1957 and 1958, the monk seal bred on six atolls of the Leeward Hawaiian Islands; by 1968, it bred regularly on five. It is postulated that during this 10-year period about 6 per cent of the world population of this seal disappeared. A recent report (1971) indicates that the monk seal is attempting to recolonize isolated islets at Midway Atoll.