In the second week of October, 1994, four loggerhead turtles, Caretta caretta, were captured in eastern Long Island and outfitted with satellite transmitters. The four turtles, ranging from 12.6 kg to 26.6 kg, were captured in pound nets within 10 km of each other. All were apparently beginning their migratory movements eastward at the time of capture. Three of the four turtles were untagged, while the fourth had been captured in Long Island waters twice previously staring in July, 1994. All turtles were released from the shore near Napeague State Park on October 10 and 11. This location is within 10 km of their capture sites.
Almost immediately after release, all four turtles swam southwestward across the New York bight toward the southern New Jersey coast. Two individuals headed in a direct path, unswervingly through mid-shelf waters ranging from 30 - 60 m in depth. The other two followed more closely along the shores of Long Island and New Jersey, remaining in waters shallower than 40 m. The four turtles continued to migrate southward at approximately the same rate (roughly 20 km per day) at least until reaching Delaware Bay, where one transmitter stopped abruptly.
As monitoring continued, the other three turtles were tracked southward through Delaware, Maryland and Virginia waters. They remained always within the 40 m contour, which runs at a distance of less than 50 km offshore. All three individuals swam as far as the Chesapeake Bay, which was the last point of contact for one of the turtles.
The remaining two turtles continued along into North Carolina waters where both currently are being monitored.
The general patterns of movement were highly similar among all four individuals during the early period after release. All four moved relatively soon after release and continued steadily southward along the shallower waters of the continental shelf. The entire tracks of all four turtles could be encompassed by an imaginary corridor running southward over 700 km along the northeastern coastline, with a maximum width of less that 60 km. This tight grouping of turtles was observed not only spatially, as individuals migrated along the same path, but also temporally, as they travelled within the same time frame. On October 30, at least three of the turtles were located just south of the Virginia-Maryland border. After nearly three weeks of ocean travel, covering more than 400 km from the initial release site, all three turtles were within 30 km of each other.
There are also striking similarities in these travel routes to those of previous years. The four pathways observed for these migrating loggerheads during the current study are almost exact duplicates of those of a Kemp's ridley from our 1991 study and at least two loggerheads from 1992. Remarkably, on the same date of October 30 in three separate years, there were five turtles within a radius of 40 km from a central location near the Virginia border. This clustering of turtles in space and time may increase the vulnerability of turtles but at the same time may enable us to more easily regulate activities that negatively impact migrating turtles.
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