Observations:

Through surface observations, a possible pattern emerged for the movement of the baitfish. During times with a higher tide, the school would congregate in the shallow Northern side of the bay and continue along the shoreline to the Eastern beach line, our main entry point.

Late in the afternoon, the school would slowly begin to migrate across the bay using what appeared to be a set path, resulting in a visable "column" formation (6).

Figure 1

Photo Credit: Steph

Figure 2

From there, the school would break off into smaller groups and gradually disapate as night approached. Below (Figure 3) is a satelite image of Whalebone Bay. Zone 1 is the general starting position of the school during morning and early afternoon hours. The column, Zone 2, would appear mid-afternoon and the fish would then break up into smaller groups, shown as Zone 3.

Observations within the water revealed that there appaered to be a particular construction to the school, with the larger hering remaining on the outer face of the school in a less dense formation and the reef silversides composing the "body" of the school in tighter formation.

Predators observed included barracuda and tarpon. Potential predators included reef squid. Predation of the baitfish was only observed among tarpon. The tarpon appeared during the morning hours on 10/17 and 10/18 and in the early afternoon on 10/16. The tarpon appeared in small schools, numbering four or less and feeding was observed in all instances. Barracuda were present during 10/17 in an afternoon snorkel. Anecdotal data from Dr. Robertson and Dr. Livdahl stated that there were numerous barracuda, including a school of three. My observations were of a single barracuda traveling in a triangle or zig zag pattern from the rocky shore across the sandy middle and back to the shoreline. This is often a predatory behavior (3) and the school was starting to move across the bay during this observed behavior.

The number of fish within the school appeared to diminish over the course of the week. Also of note is the large amount of floating sargasm algae that drifted into the bay during the trip. During our time in Bermuda, a full moon occured as well, which has been linked to mating habits of the baitfish (4,5,9,10).