Nahant:
Snails occupy an important ecological niche of the rocky intertidal zone. As both a primary food source as well as a consumer of algae, snails are a vital member of the intertidal community. They spend the majority of their adult lives within the intertidal, usually within the middle to high zones (Underwood and Chapman 1994. Dessication is a danger for any snail, especially in such a changeable environment. The tidal cycles provide the source of moisture for these snails but is this also a major source of movement for them?
Littorina sp. is an extremely prevalent snail in the rock intertidal of New England. On any given intertidal zone there could be thousands of individuals. Given this as well as their size and similar features, the movement patterns of these snails is hard to determine. Their attachment to a substrate has been studied however (Davies and Case 1997). The results of that experiment suggest that Littorina sp. could easily be dislodged by the energy imparted by tidal currents. This experiment was to look at individuals to see if they were dislodged from the middle intertidal zone by the changing of the tide. Given the force exerted by the tide, the individuals were thought to move >5m within 25 tidal cycles.
Bermuda:
The coral reefs of Bermuda are a very large tourist attraction, snorkelers and divers flock to this island by the thousands every year to view these beautiful creatures as well as the other life forms that surround the reefs themselves. Vibrant colors abound on healthy coral reefs but does this mean that there are many different species of corals? Bermuda has become significantly more industrialized in the last hundred years mostly due to this large influx of tourism. In such a small place, the environmental impact of these changes is sure to be large.
The northern shore of Bermuda is the location of the airport as well as its main shipping port. The construction of both of these has resulted in dredging and dumping of waste into the waters. Both of these are well known to negatively impact corals (Rogers 1990)(Hughes 1994)(Pastorok and Bilyard 1985). This experiment was conducted to survey sites on both the north and south shores of Bermuda to see if there was any difference in the diversity of corals between the two sites, a possible impact of the environmental changes.