Lucinda from Knox County,
I noticed that temperature data at equipment depth was not available in your first two logs. Would that be important data in determining the forms of sea life that you might sample? Was the gauge malfunctioning? Assuming that the temperature decreases at greater depths, is the interior of the submersible heated for the comfort of the crew?
Temperature is indeed one of many factors that may influence a species' presence and growth in the ocean. On 8/17/03, the water temperature during the Neuston net deployment was inadvertently missed during transcription, but has now been added to the page. When a Tucker trawl is deployed, it carries with it its own temperature/depth gauge. Upon retrieval, this mini-computer prints out the collected data for the duration of the submersion. Temperature is automatically shown on a graph, plotted every five minutes. Without picking a specific time, it would be logistically impossible to transmit all of this data. However at its deepest point, the temperature was 13.4° Celsius. You are correct about a negative correlation between temperature and depth. In the front of the submersible (the sphere end), the heat generated by all of the electrical equipment offsets the cold external temperatures. In fact, air conditioning is often necessary to keep the passengers comfortable. The aft compartment (rear end) does get a bit chilly. There are heaters back there, but they use a lot of electricity, so during deep dives the scientists and sub pilots bring along warm clothes and fleece hats.
We have not seen any turtles in the sargassum, however an adult turtle was spotted off the port (left) side of the vessel on the afternoon of the 19th. From all visible indications (i.e. overall size, shape of carapace) we believe it was a threatened species of loggerhead sea turtle called the Caretta. Caretta's largest threats are entanglement in towed or fixed fishing gear and collisions with boats. Eggs and hatchlings are susceptible to coastal development and beach erosion. An average adult's shell is 0.92m in length, though they can reach 1.2m. Fully grown, loggerheads often weigh 115kg. In the western Atlantic, they range from Newfoundland to Argentina, including the Gulf of Mexico and the Caribbean.
Sarah from Watauga County,
North Carolina, asked:
Last year our teacher, Alan Felker, found the pale orange coral that is shown on your web site. Have you determined yet if it is a new species or subspecies?
So far we have not determined whether the pale orange coral is a new species or subspecies. Identification of many of the invertebrates we have collected on our expeditions takes a long time. Most groups do not have up-to-date identification keys, so we have to do some detective work to determine what we have collected. This entails looking through scientific publications, examining comparative material in museum collections and talking to other scientists. Once that is done, we will have a more definitive answer.