Life in the Slow Lane: Ecology and Conservation of Long-Lived Marine Animals

Human Activities Affecting the Population Trends of the Hawaiian Monk Seal

Timothy J. Ragen

doi: https://doi.org/10.47886/9781888569155.ch14

Abstract. —The history of the Hawaiian monk seal is one of remarkable evolutionary persistence but recent and severe decline. The species may have persisted in the Hawaiian Archipelago for the past 15 million years. Its initial contact with humans probably occurred when Polynesians first settled the Archipelago, perhaps 2,000 years ago. Shortly thereafter, the monk seal was likely extirpated in the main Hawaiian Islands and reduced to its current configuration of six main reproductive colonies. The first written record of the species is from 1805, when it was discovered on Lisianski Island. Through the remainder of the 1800s, it was exploited for skins and oil and for food by shipwrecked sailors. By the turn of the century, at least two of the six reproductive colonies had been extirpated and the species was severely depleted. In this century, the Hawaiian monk seal has suffered more from habitat competition and loss than from direct exploitation. Habitat loss has occurred in the form of permanent human settlement with associated disturbance, deposition of marine debris, physical and biological alteration of its terrestrial environment, and biological alteration of its marine environment. Thus, human activities have played a major role in determining the status and trends of the species over the past two centuries. The historical record also suggests that human access to the Northwestern Hawaiian Islands is increasing, and such activities may become a greater impediment to recovery if they are not limited to those compatible with wildlife conservation. Unfortunately, we are often unable to predict the compatibility of proposed activities. In the face of such uncertainty, is further development of the Northwestern Hawaiian Islands worth the risk of extinction of the Hawaiian monk seal?