Time:NOAA Teacher at Sea: Annmarie Babicki
Science and Technology:
The methodology used to collect data on sharks is called bottom longlining. This is when each hook are baited with mackerel and put on a gangion. We cut our own bait and attach it to the hooks. Each hook is assigned a number, one to one hundred, so that it can be tracked. That line is then systematically hooked onto another line that runs one nautical mile. Both ends of the line have what are called hi-flyers that float vertically in the water. They are bright orange and have a blinking light on the top, so that they can be seen from a distance. There is a weight placed on both ends of the line and one in the middle. The weights help to keep the baited lines well below the surface. After the last gangion is put on, we wait one hour and then begin to pull in all hundred lines. During this entire process the ship is moving, which can be sometimes challenging, especially in bad weather.
Although the focus of this survey is sharks, data is collected on all fishes that are captured. After the fish are pulled up on deck, data is collected and recorded by the hook number. The handling of sharks is different from the handling of fish. Only sharks are fitted with a tag, which does not hurt them. There are two types of tags, but to date we have only used one type. In order to attach the yellow tag, a small slit is made underneath the dorsal fin. The tag has a sharp point on one end, which is inserted into the slit. Also a small sample (5-10 cm) of the shark’s pelvic fin is taken. This is then taken to the lab where DNA testing is done. The DNA can be used to verify known species and unknown or new species. Also, scientists can compare the population of sharks in other oceans around the globe by their DNA. What I have observed on every catch is that the scientist carefully monitors the shark to ensure it is not being stressed or could be hurt in any way.
Today we caught this beautiful and powerful scalloped hammerhead shark. When very large sharks like the hammerhead are caught, they are not pulled up by the line because it can damage them and they are too heavy to handle. Instead they are guided onto a cradle which sits in the water. Once on securely they are hoisted to the side of the ship where scientists can collect the needed data. The hammerhead weighed in at 341lb. and was 8 feet long. What a catch this was, everyone was very excited.
The day started out cloudy but eventually turned over to showers and then to a hard rain. We are feeling the effects of the tropical depression, which explains why it is difficult for me to stay standing for any length of time. I am hitting and seeing more walls than I care to! Also, it is a very bizarre feeling when the chair you are sitting in moves from one side of the room to the other. Luckily I have fended of sea sickness, but I did have a mild case of nausea, however, nothing that stopped me from continuing to work on deck. Thank goodness for Bonine.
Sleeping has not been much of a problem for me except when the ship’s engine changes. The engines make a deep loud growling sound that wakes me for just a few minutes. Being out in the fresh air does make me tired, so I have to set my alarm clock or I will sleep through my next shift. It’s hard to know what day it is because I am working a noon to midnight shift. You keep track of time by when the next sampling is due.
Being at sea and doing this type of research is definitely only for the hearty. The weather changes often as does the pace of the work. There are many jobs to do during sampling and I am trying to learn all of them. Baiting a hook and taking off bait has been frustrating, particularly since it has to be done quickly. The type of hook they use has a barb on it that goes in a different direction from the rest of the hook, so it doesn’t just slide out. We wear special gloves to protect our hands from the hooks and skin of the sharks, which can feel like sand paper or razor blades depending on the shark. They say that practice makes perfect. Well, I have a lot of practicing to do!
My next adventure is to learn how to hold sharks and not be afraid of them. I’ll keep you posted.