NOAA Teacher at Sea
Onboard NOAA Ship Oscar Elton Sette
May 2 – 25, 2004
Mission: Swordfish Assessment Survey
Geographical Area: Hawaiian Islands
Date: May 5, 2004
These data noted at about 1600 hours:
Lat: 19 27
Long: 156 02
Sky: Sunshine; clouds hanging over coastline
Air temp: 26C
Wind: 290 at 11 knots
Relative humidity: 55%
Sea temp: 26.7C
Depth: 2392 m
Science and Technology Log
Retrieving the longline takes about 2.5 hours. This morning it brought in one mahi mahi (dolphinfish) alive, and one bigeye tuna that had died on the line. Trolling afterwards brought in 3 more fish including one big eye and two yellowfin tunas. Samples were collected as yesterday.
I will give you a better idea over the next few reports as to how different samples are going to be used. I’ll start with the blood serum, liver and muscle tissue samples being taken by Michele who is from Virginia Institute of Marine Sciences (VIMS).
The blood serum contains a compound called vitellogenin. It is a precursor to a protein needed for egg yolk production. It is typically in relatively high levels in females. Environmental stresses such as persistent organic pollutants (POPs) which include PCBs, pesticides such as DDT and chemical flame retardants among others, can elevate vitellogenin levels noticeably in males. A heightened level suggests that their immune system is compromised. Serum will be analyzed for levels of that compound.
Liver, muscle tissue and serum will be analyzed by gas chromatography and mass spectrometry for the presence of POPs. From all of this it might become possible to determine if there is a correlation between level of POP and presence of vitellogenin and therefore stress on the immune system.
Surface plankton tows were done this afternoon, and tows at depth (60 meters)will take place tonight after longline is set. Tonight’s set of the longline will be north to south just a few miles west of where the first two were set. Both of those were set along a north to south line which overlapped by about 1/3. (They were not 20 miles apart as I stated yesterday) I learned that the line was intentionally cut last night probably by some fishermen who felt this line intruded upon their territory. We did recover all of our gear.
It was not until nearly the end of the longline recovery that the two fish were hauled in. Consequently, it was a long morning and as it was looking totally unproductive, Chris, our physician assistant/medical officer, suggested that the Teacher at Sea program was really a way to get people on board in case a sacrifice is needed to make the waters more productive. No wonder my students were encouraging me to participate. But later I heard that it was bad luck for our fishing to eat bananas on deck so eyes turned toward several who were in violation and ignoring that doctrine. I wonder what it will be tomorrow.
The big eye which came aboard was not identified with certainty until opened. Striations on its liver, I presume not present in other tuna species (certainly not in all) confirmed it to be big eye. I asked chief scientist, Rich Brill, the significance of those and he explained in some detail that they are part of a mechanism for keeping the liver warm. I will attempt to explain that mechanism another time. It is a neat piece of plumbing for sure.
I also observed Steve as he used a laser to determine the focal point of a big eye’s lens for each color of light. This, too, is something I will try to explain at another time. The big eye tuna’s lens was nearly spherical and about 3 cm diameter.
For a change of pace, here are a few bits about the ship that the captain shared with me yesterday. This was built for the navy in the 1980s as a listening ship for submarines. It was refitted for research in Jacksonville, FL then brought here through the Panama Canal. It can store about 30 days of food and enough fuel (160,000 gallons of diesel) to stay out comfortably for about 50 days. We can make our own fresh water at a rate of approximately 3000 gal/day.
How do eruptions of Hawaiian volcanoes compare to those like Mount St. Helens, for example?
The height of these volcanic islands affects wind speeds and sea conditions as noted yesterday. How much above sea level is the highest point on Maui? on Hawaii? If you consider its base on the ocean floor as part of its overall height, how tall is the highest peak on Hawaii? Is that taller than Mt. Everest?
It’s nice to be hearing from some of you; thanks for writing. That’s all for now.