CATHRINE PRENOT FOX
ONBOARD NOAA SHIP OSCAR DYSON
JULY 24 – AUGUST 14, 2011
Somewhere back in my family history there must have been a fishmonger, because I’ve been channeling something or someone. The entire process of watching the acoustic footprint of the ocean under the ship, deciding where to physically sample (trawl) populations, and then seeing and processing the fish that live 100 meters or more below us? Fascinating. Add to this camera drops to get snapshots of the ocean floor (more amazing footage this morning), and interesting ‘Methot’ plankton tows to sample what is available for the fish to eat and give a more accurate and complete picture? How many adjectives can I use?
Zooplankton encompass a diverse range of macro and microscopic animals. They generally eat the phytoplankton or one another. Examples include krill, copepods, jellyfish, and amphipods.
In the great food web of life, other organisms eat the zooplankton. Among them was a pod of 50+ Humpback whales in the Barnabas Trough off of Kodiak Island. They were exciting enough that I went from being sound asleep to dressed and on the bridge in less than five minutes. Issue 12, Humpback Whales: Better than any alarm clock I have ever known delves into these organisms (Cartoon citations 1, 2, 3 and 4).
Our chief survey technician, Kathy Hough, took a lot of photos the following day as we traveled from Barnabas Trough to Alitak Bay. The three photos that follow and descriptions are courtesy of Kathy.
Our team of scientists sample plankton using a Methot net, which is fine mesh and captures macroscopic organisms. We sample plankton for the same reason that we physically trawl for fish: we need to make certain what we are “hearing” is what is down there, with a focus on the types and sizes of the plankton. Additionally, knowledge about what and where plankton populations are will help with modeling the entire ecosystem. If you know where the food lives, its abundance and composition, by extension you have a much greater understanding of the predators, both pollock and whale.
(If you get a chance, check out this video about how whales hunt with bubble nets; fascinating!)
I try to spend time on the bridge every morning before breakfast. I bring up a cup of tea and watch the horizon lighten until the sun pushes its way up above the lingering clouds. This morning, I saw the green flash for the first time. The green flash is not a superhero. It is not a myth. It is not a sailor’s fish tail. It is real. Furthermore, if you still don’t believe me, the green flash is in the “bible” of maritime studies, The American Practical Navigator (Bowditch, if you are on a first name basis). I was told by Ensign David Rodziewiczthat “if it is in Bowditch, it must be true.” So there.
The green flash appears on the horizon just after the sun sets or just before it rises. For one moment on that spot the sky looks as if someone broke a green glow stick and smeared a distant florescent mark. As fast as it was there, it is gone. The name is appropriate: green flash. It occurs because light is bent slightly as it passes through the atmosphere (refraction); this bending is greatest on the horizon. Since light is made up of different colors with different wavelengths, the bending causes the colors to be seen separately. Bowditch says it is like offset color printing (nice metaphor, eh?). The red end of the spectrum is first to rise. The blue end of the spectrum is scattered the most by the atmosphere, leaving behind the momentary and memorable second of green.
Evidently, to see the green flash is considered very good luck. I already feel very lucky. I am in one of the most beautiful places in the world, on a ship with interesting and intelligent people, driving around the Gulf of Alaska learning about science and occasionally checking out whales. If I can get luckier than this… well… wow.
Tomorrow is the last day of our cruise, but I have a few more cartoons up my sleeves, so keep checking back. In the meantime, thank you to the incredible staff of the Oscar Dyson, the scientists of MACE, my rockin’ cohort Staci, and the NOAA Teacher at Sea program.
Until our next adventure,
p.s. Whales have the worst morning breath I have ever smelled. I know it isn’t really their fault–imagine having 270-400 baleen sheets on either side of your mouth that you could get krill stuck in…
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