The Impact of the Prehistoric Polynesians on the Hawaiian Ecosystem

Evidence obtained from archaeological and ancillary studies of paleoenvironment suggests that the prehistoric Polynesians had a far greater impact on the Hawaiian ecosystem than has heretofore been realized. Such impact began with the introduction, by Polynesians, of exotic plants and animals. The cumulative effects of forest clearance and habitat modification through the use of fire led to major changes in lowland ecology. Among the consequences of this transformation of the Hawaiian landscape were the extinction of endemic species, alteration of vegetation communities, and erosion. THE EXTANT BIOTA of the Hawaiian Islands represents a sadly depauperate reflection of the archipelago's flora and fauna prior to the advent of humans. This observation is not likely to startle most naturalists familiar with Hawaiian natural history. However, the consensus has long been that by far the greatest human impact on the Hawaiian ecosystem occurred in the two centuries since initial European contact. Carlquist, for instance, attributes the removal of large tracts of native dry forest to the actions of "peoples other than the Polynesians" (1970: 275). Indeed, it has been commonly assumed that the impact of the indigenous Polynesian inhabitants of Hawaii was minimal. The anthropologist Kelly maintained that "works of Hawaiians, both on land and in the sea, were so carefully planned, engineered and executed that they enhanced productivity without massive environmental degradation" (1975: iii, emphasis added). Sufficient evidence is now available (accumulated largely over the past decade by archaeologists with interdisciplinary support from a range of natural sciences) to question seriously the orthodox view regarding minimal prehistoric Polynesian impact on the Hawaiian environment. In fairness, I must note that some naturalists have realized the I Manuscript accepted 30 October 1981. 2 Bernice P. Bishop Museum, Department of Anthropology, P.O. Box 19000-A, Honolulu, Hawaii 96819. potential of prehistoric Polynesians to disrupt their island environments. Zimmerman, for example, opined that prior to the Polynesian colonization ofHawaii, the land was "densely forested down to the seashore," and that "the fires of even the early Polynesians swept away vast tracts of woodland" (1963: 57-8). Similar views have been expresed by Atkinson (1977), Degener and Degener (1974), Egler (1942), Fosberg (1972), and Newman (n.d.). Nevertheless, until quite recently there has been a dearth of direct, paleoenvironmental data bearing on the question of pre-European human impact on the Hawaiian ecosystem. This paper provides a synopsis of such evidence from the viewpoint of an archaeologist who has been actively engaged in research on the question of human-environment interaction in Polynesia. I believe such a synopsis to be timely for at least two reasons: First, the popular orthodoxy of indigenous peoples in symbiotic "harmony" with nature should not go unquestioned. Second, by presenting the evidence thus far accumulated, other natural scientists may be inspired to contribute their analytical efforts, and the archaeological study of human-environment relations requires interdisciplinary cooperation. I hasten to add that over the course of the past decade of investigations, far more questions than answers have emerged. Some of the most startling evidence regarding, for example, avifaunal extinctions and shoreline changes has been obtained only within the past year or