06/09/04 - Corals & invertebrates galore
|Lat:||28° 47.2 min N|
|Long:||79° 39.6 min W|
We are in the beautiful waters of the Gulf Stream. The blue is so rich it is almost iridescent. In the book The Deep Atlantic the author says, "In 1497 when John and Sebastian Cabot sailed up the eastern coast of North America in search of the Northwest Passage, they noted that the unaccountable warmth belowdecks fermented the beer in the hold and turned it sour. They thus became the first explorers to record their observations of what would later be known as the Gulf Stream."
We are continuing to explore the Gulf Stream. It varies between 20 and 40 miles wide and moves approximately 70,000,000 tons of water per second . After reaching our study site last night we towed plankton nets. The net is launched off the starboard (right) side of the ship with a large A-frame crane via a pulley and a winch. We collected both zooplankton and phytoplankton in the plastic container at the narrow end of the net.
The sub went down about 8:30 am with Chief Scientist Steve Ross from the University of North Carolina-Wilmington (UNCW) in the bow and Co-Principal Investigator Ken Sulak of the US Geological Survey (USGS) in the stern. This year we are using a high-definition video camera mounted on the outside of the sub in addition to the digital still cameras and the internal Mini-DV cameras. It is a challenge to fit the scientist in the compartment in addition to all of the gear! The sub returned with several coral samples including a pinkish "bamboo" coral. It has dark bands around the branches which make it resemble bamboo. We also collected some samples of the substrate (the surface on which an organism grows or to which it is attached) to look for macroinvertebrates that might be found there.
Between dives we pulled a few more plankton tows and waited for the subs battery to recharge. The sub launched again at 4:30 pm with Ken Sulak in the bow and Co-Principal Investigator Martha Nizinski from the National Oceanic and Atmospheric Administration (NOAA)/National Marine Fisheries Service (NMFS) in the stern.
Martha and Ken returned from their dive with a grand assortment of corals and invertebrates. There were at least 10 species of corals and 10 species of sponges as well as several urchins. Two of the urchins have very soft bodies. Instead of having an entire "test" (or hard shell) these urchins have small hard pieces of shell held together by connective tissue. Their bodies are filled with water. Some also have "pedicellaria", small structures that look a bit like tiny crab claws and can only be seen under a microscope. Many species have pedecellaria that pinch or sting. One urchin we collected did sting.
The habitat in this area appears to be quite different from the
sites we have visited off the coast of the Carolinas in previous
years. Although the depth and range would suggest that we would
find the same species of fish and invertebrates, we have been
surprised at the differences. We have not found much Lophelia
(the deepwater corals we are most interested in) at all.
The plan is to steam north to our next study site off the coast of Jacksonville, Florida. We should be there in time to run some fathometer transects, which measure the water depth in a gridded fashion, to get an idea of the bottom topography and choose our ideal sub study site for tomorrow's morning dive.
 The Deep Atlantic: Life, Death, and Exploration in the Abyss, by Richard Ellis; Knopf; 1st edition (October 8, 1996); p.7.
 The Seaside Naturalist: A Guide to Nature Study at the Seashore, by Deborah Coulombe; Prentice Hall; (April 1990).
|Previous Log||Next Log|