NOAA Teacher at Sea
Onboard NOAA Ship Oscar Elton Sette
May 2 – 25, 2004
Mission: Swordfish Assessment Survey
Geographical Area: Hawaiian Islands
Date: May 7, 2004
Lat: 18 41N
Long: 158 34W
Sky: scattered cumulus clouds; bright and sunny
Air temp: 26.6 C
Wind: 87 degrees at knots 6.7 knots
Relative humidity: 50%
Sea temp: 26 C
Depth: 4558 m
Scientific and Technical Log
We left the shelter of the Kona coast and steamed all night toward Cross seamount arriving there between 0900 and 1000 hours. We trolled a couple lines across it for several hours but pulled in no fish. This is where we wanted to lay the line tonight, but in communicating with a fishing vessel in the area, that crew indicated they have 30 miles of line in the water now. Protocol, I presume, says it’s their place for now so we will respect that and go elsewhere.
Elsewhere is another seamount about 45 miles west and slightly north of Cross. But why are we hanging out at these things called seamounts? Rich (remember, chief scientist) explained to me that above seamounts are local currents called Taylor Columns that sort of swirl around above these features. Small fish tend to concentrate within these and, of course, that attracts the big boys. Cross is well known for that effect due to its shallowness (182 fathoms). The one we are going to is much deeper and consequently does not have as dramatic an impact as Cross.
Here is a bit about a couple tools that we are not using on this ship for this mission. One is called the Acoustic Doppler Current Profiler. It sends out a high frequency signal and allows determination of current direction and speed under the ship. Another is the CTD (conductivity, temperature and depth). This circular array of water sampling bottles is lowered into the water. Temperature and conductivity are monitored and recorded continuously as it moves through the water. On ascent, bottles can be triggered to close at specific depths thereby bringing water samples from different levels in the water column for further testing on board.
More about life on the ship:
There will be no shore time during this trip, but there are several forms of entertainment aboard. Just listening to crew members speak of other places and projects around the globe they have participated in on NOAA vessels is fascinating. There is a small work out room and a couple rooms where we can view videos/cds or watch TV. There is quite a library of viewing materials and books available. Some crew members have their own TVs and stereo equipment in their cabins. On the more mundane side, there is a laundry to do personal items and once a week stewards give us a change of linens and towels.
Communication with home:
We download and upload email three times per day: 0700, 1300, and 1900 hours. Phone calls can be made but they are expensive and generally reserved for emergencies. The ship’s total communications bill can run up to $10,000 per month. So far, a typical day for me has been something like this after breakfast (0700-0800): collect samples from longline catch, assist cleanup, cleanup self, lunch (1100-1200). Check emails, enter some notes to log until tiring of that, R&R (reading, snoozing on shaded deck, interview someone or observe their work) and help with any fish coming in on troll lines. Dinner (1630-1730), R&R, input to log, help set longline (2000 -2130), finish the day’s log and send to Washington (that makes me sound pretty important doesn’t it?), R&R, and to bed 2300-2400 hours.
Since we did not set a line last night and no fish came on by trolling today was kind of slow. I used the time to have a tour of the bridge by executive officer Sarah and electrical technician, John. It was very interesting to learn more about the ship’s scientific monitoring abilities (as briefly and incompletely described above), navigation and safety features for times of distress.
Crew assisted me to string my swordfish bills so to drag along behind us. This is done to get some of the flesh and oils out of them. I am told that this will take a week or more to accomplish.
Estimate the distance in miles between yesterday’s and today’s position (today at 2018 hours we are at Lat 18 53 N and Long 158.59 W).
What is a seamount?
Looking at the nautical chart on the bridge I can see the top of Cross seamount is at (a shallow) 182 fathoms. We are headed to one that is 406 fathoms. Between the two the chart shows a maximum depth of 2585 fathoms. What is the depth of the water over the seamounts and the deepest point between them in feet?