This study develops the foundation for a comprehensive data-gathering program-a monitoring protocol--for Block Island, Rhode Island's Great Salt Pond and its watershed. The history of the Great Salt Pond is unique: humans have been present since 500 B.C., and the pond was artificially breached to the ocean in 1895. Because humans influence all aspects of the Great Salt Pond's natural system, attempting to separate those processes which are "natural" from those which in response to human influence is nearly impossible. I assert that there are four major processes that threaten to alter the present state of the natural system: loss of land and marine habitat; introduction of nonnative species; overfishing; erosion and sedimentation. Based on an assessment of scale, trend, rank and persistence, I argue that habitat loss is the process that poses the largest threat to the present state of the natural system, and that changes in the size of the ocean breach will have broad-reaching effects on the biology of the pond.

Human impacts on the pond not only affect the natural system, but also can affect human health and welfare. I identify twelve variables that have the potential to affect human health and welfare in the Great Salt Pond and its watershed. Of these, year-round island residents affect eleven, summer residents affect seven, and tourists affect five. Human influence is increasing over time: tourism has grown by 138 percent since 1978; car visitation has increased by 575 percent; 80 percent of all housing units built since 1960 are for seasonal use. Because Block Island is a summer vacation hotspot, human presence is strongly seasonal. I argue that human influences that pose the highest risk to the watershed are household septic effluent, marine overboard sewage discharge, and underground storage tanks.

To create an effective monitoring program, indicators of change need to be selected that can alert public officials in a timely way. I recommend a combination approach that consists of monitoring high risk factors at their sources together with tracking general indicators. General indicators often mask the source of pollution, but they give an overall sense of the state of the system. I list twenty-five indicators that could be monitored, and rank as these actions as high priority: monitoring water clarity, tracking island summer populations, regularly inspecting septic tanks, mapping habitat change, and establishing compliance with the Federal No Discharge Area designation.

Implementation of a monitoring protocol will require more input from island groups and state organizations. My analysis presents recommendations for how to go about monitoring, and makes suggestions for the suitable delegation of monitoring tasks. I also discuss relative cost of monitoring activities, and the frequency of measurements, which may be appropriate. The next step is to convene interested stakeholders, discuss management goals and budget options, and to make concrete plans to begin.