Charleston
Gyre |
February 3, 2003 Most marine fish have
complex life history Eggs and fish larvae die
in many ways. They can starve. They can be eaten. They can be transported
away from suitable habitats. The survivors are those lucky few who get
enough to eat, avoid the myriad of predators, and are transported favorably
by ocean currents. These few larvae then enter juvenile habitats and
must again get enough to eat and avoid predation. After making it through
this early life cycle gauntlet, the surviving fish join the adult population
and reproduce, initiating the cycle again. Determining which factors
dominate early life cycle survival will provide important information
as to the health of fish populations. Bad years could be marked by not
enough food or cold temperatures. Good years could be caused by favorable
winds or few predators. Understanding the factors that affect early
life cycle survival will contribute to NOAA’s mission of building
sustainable fisheries and sustaining healthy coasts. This cruise finds us north of the Charleston Bump studying ichthyoplankton. Why are we working here? The Gulf Stream runs northward along the edge of the southeast United States continental shelf. After passing over the Charleston Bump, the Gulf Stream often veers to the east and then back to the northwest. This veering sets up counter-clockwise rotation, or cyclonic rotation, and deep, nutrient rich water is sucked up towards the surface. The area of semi-permanent cyclonic rotation is termed the “Charleston Gyre” and we are exploring whether the “Charleston Gyre” is a good place for the survival of ichthyoplankton, or fish eggs and larvae. The cool nutrient rich
water that upwells in the center of the “Charleston Gyre”
fuels the growth of single celled plants called phytoplankton (phyto
is the greek root for plant). The plants are food for zooplankton, which
are small animals living in the plankton (zoo is the Greek root for
animal). Marcy Hutchinson, Physiology
and Ecology Technician Some of Marcy’s duties include sorting and identifying zooplankton, acquiring and analyzing chlorophyll samples and help write cruise reports. She’ll be working this summer in a marine protected area in the Dry Tortugas. The thing she likes the
most about her job is the field work and being outdoors. What she doesn’t
like is getting seasick! She decided that if she could be any sea creature
it would be a dolphin. Why? They’re fast, graceful, intelligent
and seem to have a lot of fun. |
Ph.
843-953-7263 |
Project
Oceanica Dept. of Geology & Environmental Geosciences College of Charleston Charleston, SC 29424 |
Fax
843-953-7850 |