Mission: Shark Longline Survey
Geographical Area: Southern Atlantic/Gulf of Mexico
Date: August 22, 2011
Weather Data from the Bridge
Latitude: 27.56 N
Longitude: 83.73 W
Wind Speed: 5.95 kts
Surface Water Temperature: 30.50 C
Air Temperature: 31.60 C
Relative Humidity: 66.00%
Science and Technology Log
Okay, so I admit, I can’t learn enough. I just THOUGHT I was doing my last post, but I have to share with you some more information I learned toward the end of our journey. So if you want to learn some “cool facts,” today’s post is for you!
Cool Fact #1: Sargassum– This is a type of seaweed we saw in the ocean today alongside the ship. It mats together in large clumps and serves as a refuge for larval fish. It also is a type of “floating community” with lots of fish, such as mahi mahi, congregating around it. Newly hatched sea turtles find refuge in sargassum.
Cool Fact #2: Shark skin samples and fin clips — All week long I have seen shark skin samples and fin clips taken, but today I found out from two of the scientists on our survey, Dr. Trey Driggers and Adam Pollack, what is done with these. The skin sample is done so the shark can be identified down to the species. For example, there are 3 species of smooth dogfish in the Gulf of Mexico. They all look the same externally. Keep in mind, the smooth dogfish shares the same genus (Mustelus), but the species differs. One of the ways to tell them apart is to look at their skin sample under a microscope. For this reason, every shark that is caught has a small sample of skin taken that is placed in alcohol for preservation.
When it gets to the lab, the scientist looks at the dermal denticles (scales) under a microscope. If the denticle has 1 point, its species is either canis (common name– smooth dogfish) or norrisi (common name–Florida smooth dogfish). If it has 3 points, its species is sinusmexicanus (common name- Gulf smooth dogfish).
The fin clip is collected and archived and later a DNA analysis is performed. They are compared to fish of the Gulf of Mexico to tell if they are genetically different or similar. This information is used for stock management.
Cool Fact #3: Otoliths– I have been assisting the scientists this week in getting the otoliths from various fish, such as red grouper, yellowedge grouper, and blueline tilefish. Today I got to take the otoliths out myself. By “myself,” I mean with the help of skilled scientist, Adam! It was neat! So what are otoliths? They are the ear bones of fish. They tell the age of the fish, much like the annual rings of a tree trunk do. These are collected and put in an envelope with the identification number in order to be observed under a microscope in the lab.
Last night after our shift ended at midnight, by the light of the moon we watched a pod of about 25 dolphins chase flying fish and play in the wake of the boat. I sure will miss all the sights the sea has to offer. I will especially miss the people.
I mentioned in an earlier post that NOAA Ship Oregon II is like a city. It has everything needed on board to run smoothly. There are people with numerous kinds of backgrounds. Each and every one of these individuals is needed in order to successfully complete a NOAA mission, whatever it may be.
So now I’m talking to you kids. Have you ever thought about what you want to be or do when you grow up? How about starting now? How about you adults, have you ever thought about trying to do something new and exciting? I have a question for you (and I would like for you to put your answer in the poll): If you could choose any job on this ship, what would it be?
If you will notice from my posts, I did not just cover the science end of this ship. There are so many other careers going on to make these surveys work. It’s a team effort. Under the leadership of Cap Nelson, that’s exactly what you have here on NOAA Ship, Oregon II: a team effort. And that’s what makes this ship a model for any team to follow.