NRC 100 Environment and Society

Horseshoe crabs, those mysterious ancient mariners, lured me into the sea as a child along the beaches of New Jersey. Drawn to their shiny domed shells and spiked tails, I could not resist picking them up, turning them over and watching the wondrous mechanical movement of their glistening legs, articulating with one another as smoothly as the inner working of a clock. What was it like to be a horseshoe crab, I wondered? What did they eat? Did they always move around together? Why were some so large and others much smaller? How old were they, anyway? What must it feel like to live underwater? What else was out there, down there, in the cool, green depths that gave rise to such intriguing creatures? The only way to find out, I reasoned, would be to go into the ocean and see for myself, and so I did, and more than 60 years later, I still do.

As in the terrestrial environment, most data collection from freshwater habitats to date falls into the survey, surveillance or research categories. The critical difference between these exercises and a monitoring project is that a monitoring project will clearly identify when we need to make a management response. A Model for Conservation Management and Monitoring Monitoring (as defined by Hellawell) is essentially a tool of practical conservation management, and Fig. 1.1 shows a simple, but effective, model for nature conser- tion management and monitoring. The need for clear decision-making is implicit in this model. First we must decide what would represent a favourable state for the key habitat or species, and then we must decide when to intervene if the state is (or becomes) unfavourable. A third, often overlooked, but equally important, decision concerns when we would consider the habitat or species to have recovered; this is unlikely to be the same point that we became concerned about it. This decision not only has resource imp- cations, it can also have major implications for other habitats and species (prey species are an obvious example). All of these decisions are essential to the devel- ment of an efficient and effective monitoring project.

Besides the erroneous assumption that tropical fisheries are 'open access', the cases demonstrate that pre-existing systems (1) are concerned with the community of fishers and ensuring community harmony and continuity; (2) involve flexible, multiple and overlapping rights adapted to changing needs and circumstances; (3) that fisheries are just one component of a community resource assemblage and depend on both the good management of linked upstream ecosystems and risk management to ensure balanced nutritional resources of the community; and (4) pre-existing systems are greatly affected by a constellation of interacting external pressures.