NOAA Teacher at Sea
Onboard NOAA Ship Fairweather
May 17 – May 27, 2010
NOAA teacher at Sea: David Altizio
NOAA ship Fairweather
Mission: Hydrographic survey
Geographical Area of Cruise: SE Alaska,
from Petersburg, AK to Seattle, WA
Date: Friday May, 21
Weather Data from the Bridge
Position: Behm Canal to Customhouse Cove,
Shoalwater Pass and Princess Bay
Time: 0800 on 5/21
Latitude: 550 23.26’ N
Longitude: 1300 57.13’ W
Visibility: 10 miles
Winds: light with variable directions
Waves: Less than one foot
Dry Bulb Temperature: 10.00C
Wet Bulb Temperature: 8.50C
Barometric Pressure: 1016.5 mb
Tides (in feet):
Low @ 0111 of 3.7
High @ 0713 of 13.1
Low @ 2011 of 1.0
High @ 2011 of 14.4
Science and Technology Log
I spent the morning on the smallest and most maneuverable of the launch boats on the Fairweather called an Ambar. Unlike the other launch boats that I was previously on, this one does not have a sheltered area so full cold weather/rain gear was needed. Our task was to collect sediment samples from the bottom of Shoalwater Pass and Princess Bay. We were the first of four launches to go out on this day. As we were being lowered down from the ship everybody started to notice porpoises all around us.
Once the Ambar was deployed the porpoises began racing alongside the boat. They stayed with us for a few minutes.It was an awesome sight and an experience that I will never forget. Later, at lunch I was talking with the CO (commanding officer) and he told me that he had never quite seen so many porpoises ride alongside a launch boat for such a long time.
What I saw were Dall’s porpoises (Phocoenoides dalli)a species that is only found in the North Pacific; from the Bering Sea and the Gulf of Alaska (spring to summer) and in coastal waters as far south as Baja California (fall to winter). Their unique body shape makes them easy to distinguish from other porpoise species. They have a very thick body and a small head. Their coloration is much like an Orca (killer whale), with their bodies being black with white patches on their underside. Dall’s Porpoises are hugely active and playful creatures. They will often zigzag around at great speed on or just below the surface of the water creating a spray called a “rooster tail”. They often appear and disappear quite suddenly. They will approach boats and ride alongside, but may lose interest, unless the boat is travelling quickly.
Dall’s are usually larger than other species of porpoises, growing up to 2 or 3 meters in length and weighing between 280 to 450 lbs. This species of porpoise can live as long as 15 to 20 years. They feed mostly on squid and a variety of fish. They are the fastest of all porpoises; they can swim at or up to 35 miles per hour. They often appear in small groups. Today, I would say there were at least 15 to 20 of them, but they were so fast and difficult to count.
After the excitement, we drove over to Shoalwater Pass and began collecting our first of eight bottom samples. The information gathered from these samples is very helpful to ships that might be anchoring in a particular area. For example, if you anchor in deep mud, the anchor could become trapped or stuck in the mud, or if the bottom is very rocky the anchor would not be able to set into the bottom at all.
In order to collect the bottom sediments we had to lower down a heavy sampler and allow it to hit the bottom. In deeper water this was definitely more difficult. As you can see, we had to pull the sampler up by hand and hope that it had closed and collected sediments. It did not close every time we lowered it, so some of the site required more than one drop which made the task even harder.
Of the eight bottom samples we collected, they ranged from sticky mud to angular stones, to pebbles. The classification system used for bottom samples includes the following names: mud, clay, silt, sand, stones, gravel,boulders, lava, coral, and shells. After they are named, if they are sediments they are then classified by size range and then adjectives are added to specifically describe the sample, such as: fine, medium, coarse, broken, sticky,
soft, stiff, volcanic, calcareous, hard, soft, light, dark, small, medium, and large.
After each sample was taken we used a laptop (that can get wet) with a GPS receiver attached to it to log our exact positions. This information will be part of the charts that will be made when the area is completely surveyed.
As already stated one of the highlights of my trip so far has been the Dall’s porpoises that raced alongside us. That is something that I will never forget. This was not the only wildlife sighting of the day. When we were transiting from one sample area to another, I spotted a bald eagle and pointed it out to two of the other guys on my boat. What happened next was awesome.
Once we saw the eagle, which as I have told you are all over the place, we noticed another smaller bird in front of it. The eagle was chasing him and was hot on his tail. Suddenly the smaller bird had nowhere to go and did a nosedive into the water. This was so cool. Then the eagle proceeded to circle the smaller bird from above so as to say stay down there. I also saw numerous whale spouts from a distance, too far to tell what type. While back on the Fairweather for lunch a stellar sea lion was swimming right along the starboard side of the ship. When I went outside to see him, he surfaced, came out of the water about chest high looked right at me and swam away, never to be seen again.
SE Alaska is truly a special and magical place. Not just for wildlife, the scenery is absolutely spectacular. I can’t wait to see what another day brings with it.
Animals Seen Today
Dall’s porpoises Bald eagle chasing smaller birds A few stellar sea lions along the starboard side of the Fairweather Whale spouts from a distance