Mission: Shark Longline Survey Geographical Area: Southern Atlantic/Gulf of Mexico Date: Sunday, August 7, 2011
Weather Data from the Bridge
Latitude: 34.22 N
Longitude: -077.05 W
Wind Speed: 16.38 kts
Surface Water Temperature: 28.10 C
Air Temperature: 28.90 C
Relative Humidity: 82%
Barometric Pressure: 1010.80 mb
Science and Technology Log
Last night, we finished up our last station. In total, we had 761 catches for the whole survey across a dozen different species. The sharks we caught ranged from small (less than 1 kilogram) to very large (134 kilograms). For the very small sharks, I could sometimes see the spot where the umbilical cord was attached.
Over the last few days, I learned about shark reproduction. Sharks produce “pups” (baby sharks) through three different ways. One way is the pup develops in a placenta and is nourished by the mother. It is then born live (called viviparity). A second way is an egg is produced and hatches inside the mother but there is no placental connection. The embryo eats the yoke in the yoke sac until it is completely absorbed. The pup is then born free-swimming. (called ovoviviparity). The third way is the mother lays a fertilized egg in the water and the pup is born externally (oviparity). The species we saw the most, the Atlantic sharpnose of the family Carcharhinus, produce pups through viviparity. For some species like the sandtiger shark, one of the pups will eat the other eggs inside the womb for nourishment and then just that one pup will be born. Talk about survival of the fittest!
I was able to see what a shark embryo looks like. Ian Davenport, an evolutionary biologist from Xavier University of Louisiana is studying developmental biology in female sharks. Ian is on the day shift with me and he was able to show me embryos from a pregnant female. The mother was not alive when we caught her, so we made use of the body as much as possible for scientific purposes.
You might be wondering how we can tell the difference between a male and a female shark. This is done through visual inspection. We look for the presence of “claspers” on a male shark. A clasper is a male anatomical structure. Males have two claspers. If there are no claspers, it’s a female.
I experienced “shark burn” for the first time while handling an Atlantic Sharpnose the other day. I didn’t feel anything at first, but while I was taking measurements on its length, its tail rubbed me the wrong way. A few hours later, I noticed what felt like a stinging rash on my arm. Sharks have unique skin made of modified teeth called dermal denticles. These scales point towards the tail and help the shark swim quickly and efficiently. When you rub a shark from head to tail, it feels silky. If you rub it in the opposite direction, it feels like sandpaper. I learned this lesson the hard way!
Species Seen: Tiger Shark
Atlantic Sharpnose Shark
School of Dolphin Fish
My team had a great sighting of a large hammerhead recently. It was about 10 feet long. We tried to use a tagging pole from the side of the boat instead of using the cradle but the hammerhead was so strong, it broke right off the line. Even though we couldn’t collect data, it was still exciting to see such a massive shark and get an idea of its power.
Last night we finished our final station and we are heading back to port in Charleston, SC. It was really great to work with such amazing people, not only on my shift, but everyone aboard the Oregon II. I came across a variety of people with interesting careers and backgrounds. Even though the work was sometimes physically demanding, it was informative and engaging the entire time. Thanks to NOAA for giving me the opportunity to participate in the Teacher at Sea program. I learned so much that I plan on bringing back to my students! A big thanks to Mark Grace, our chief scientist, for answering many of my questions, providing feedback, and showing me how to do many tasks. I also want to thank the day team for helping me learn so much – Amy, Heather, Jim, Ian, Cliff, Jeff, Mike, and our XO Jason for giving me feedback on my blog. Thanks to Paul and Walter the amazing cooks. To the entire crew of the Oregon II – thank you! I had a great experience!
Mission: Shark Longline Survey Geographical Area: Southern Atlantic/Gulf of Mexico Date: August 3, 2011
Weather Data from the Bridge
Latitude: 32.50 N
Longitude: -079.22 W
Wind Speed: 17.75 kts
Surface Water Temperature: 28.60 C
Air Temperature: 29.90 C
Relative Humidity: 71%
Barometric Pressure: 1009.06 mb
Science and Technology Log One reason the shark longline survey exists is because the populations of many types of sharks are in decline. There are several reasons for this – finning is one reason. “Finning” is the process where the shark’s fin is removed from the rest of its body. Since usually only the fin is desired, the rest of the body is discarded. Shark fins are used for things like shark fin soup – a delicacy in Asian cultures. When the fin is cut off and the rest of the body stays in the water, the shark can not swim upright and eventually dies. While some regulations have been passed to prevent this, shark finning still occurs. Sharks are also overfished for their meat. As a result many shark species have become vulnerable, threatened or endangered. Large sharks can take longer to reproduce. Therefore, they are more likely to be threatened or decline in their numbers.
Sharks are at the top of the food chain. They keep prey populations in control, without which the marine ecosystem would be unstable.
This is why the mission of the shark longline survey is important. The identification tags and roto tags used during this survey along with the data collected will help scientists assess the abundance of species in this area. They can then provide recommendations for shark management. On average, we are collecting data on 10 sharks per line (or 10%), although our catch rates are between 0% and around 50%. With 50 stations in all, that would be data on approximately 500 sharks (on average).
There are more than 360 species of known sharks. Below is a list of some that we have seen and measured during our survey. The IUCN red list (International Union for Conservation of Nature and Natural Resources) classify these sharks with a status:
Atlantic Sharpnose Shark – Least Concern
Blacknose Shark – Near Threatened
Silky Shark – Near Threatened
Tiger Shark – Near Threatened
Lemon Shark – Near Threatened
Dusky Shark – Vulnerable
Sandbar Shark – Vulnerable
Scalloped Hammerhead – Endangered
During my shift, we sometimes catch things we do not intend to catch. We might reel in fish or other sea creatures that get caught on the hooks. This is called “bycatch”. While everything is done to try to catch only the things we are interested in studying, bycatch occasionally happens. The fish are only on our line for 1 hour, so their survival rates are pretty good. Our bycatch data is a very important element and also contributes to management plans for a number of species like snappers and groupers.
Just the other day, we caught a remora (a suckerfish that attaches itself to a shark’s side). Remoras and sharks have a commensalism relationship – the remora gets leftover food bits after the shark eats, but the shark gets no benefit from the remora. We quickly took down its measurements in order to get it back into the water quickly. Other bycatch included an eel, and black sea bass.
We also caught a red snapper. Our chief scientist, Mark, showed me the two small, tiny ear bones called “otoliths” in the snapper’s head. These bones provide the fish with a sense of balance – kind of like the way our inner ear provides us with information on where we are in space (am I upside down, right side up, left, right?). You can tell the age of a snapper by counting the annual growth rings on the otoliths just like counting growth rings on a tree.
My experience aboard the Oregon II has given me a better understanding of the vulnerability of some shark species. While many of us may think that sharks can be threatening to humans, it is more accurate the other way around. Sharks are more threatened by humans than humans are threatened by sharks. This is due to our human behaviors (mentioned above).
Today I saw dolphins following our boat off the bow. There were about 6 or 7 of them all swimming together in a synchronized pattern (popping up for air all at the same time). It was really quite a treat to watch.
I’m also amazed by the amount of stars in the sky. With the lights off on the bow, you can really see a lot of stars. I was also able to see the milky way. There have been many storms off the horizon which are really cool to watch at night. The whole sky lights up with lightning in the distance, so I sat and watched for a while. With tropical storm Emily coming upon us, we may have to return to port earlier than planned, but nothing is set in stone just yet. I hope we don’t have to end the survey early.
Species Seen :
Black Sea Bass
Atlantic Spotted Dolphins
Mission: Shark Longline Survey Geographical Area: Southern Atlantic/Gulf of Mexico Date: Sunday, July 31, 2011
Weather Data from the Bridge Latitude: 30.39 N
Longitude: -080.41 W
Wind Speed: 13.67 kts
Surface Water Temperature: 29.50 C
Air Temperature: 29.10 C
Relative Humidity: 78 %
Barometric Pressure: 1016.43 mb
Water Depth: 37.10 m
Science and Technology Log
A part of any good experiment or survey is the careful collection of data. We know that without a good data collection plan, our results may have error or be open to wide interpretation. The shark longline survey has been going on for the past 17 years in order to understand the abundance of shark species in this area. It has standard procedures and protocols that we must follow so that each survey is consistent. Hmm…that sounds similar to what we do in science class!
Every time we reach a “station” (a pre-designated spot) our team collects data on the characteristics of that area. One piece of technology we use to do this is called a CTD (which stands for conductivity, temperature, and depth). This instrument is placed overboard with the help of a winch and takes measurements for several minutes. Conductivity tells us information about the salinity (amount of salt) of the water. The device also reads the temperature, depth, levels of chlorophyll, dissolved oxygen, and can give us water samples. This is important because every time we change stations, we want to know about the conditions of that area. The data from the CTD is then sent electronically to a data room and graphed.
We also collect data on the color of the ocean water, the wave height, and the percentage of cloud cover. This last one is a bit tricky because it is so subjective.
It is also important to collect data consistently. There are two shifts aboard the boat – the day shift (which I am on) and the night shift. Each shift is 12 hours long. We collect data even in the middle of the night. What do you think would happen if we only collected data on sharks during the day time?
There are several measurement tools we use. The measuring board allows us to place a small shark on the board and read its length in millimeters. We take two readings – one for the length from the snout to the fork where the tail splits, the other for the entire length of the shark from end to end. The spring scale is used to measure the shark’s weight in kilograms. If the shark is too big for either of the above tools, we will take measurements in the cradle. We use a flexible tape measure for length, and record weight through a scale on the cradle. We know the cradle’s weight, so all we have to do is record the total weight of the cradle with the shark in it and subtract (see kids, math in the real world!)
We tag some sharks with a Roto clip and/or an identification marker. All of the data is written down on a clipboard and then entered into a database. Pictures are also taken with a camera so that we can photo-document the catch. Each picture is renamed with the corresponding ID number of the tag so that we have a database of images.
I mentioned earlier that we have satellite TV access on the boat. Actually there are three – one in the lounge and two in the galley. Funny enough, we have the perfect program to watch this week on the Discovery channel…happy Shark Week everyone! Yesterday, we had to postpone doing our longline survey at one station due to a distress call from a small boat that was 10 miles away.
The crew aboard our ship got ready to perform a search and recovery operation by getting the Zodiac rescue boat ready. But as it turned out, another vessel was able to aid them faster, and we resumed our work. I was amazed to see the crew jump into action and be ready so fast.
Species Seen Today
Atlantic Sharpnose Shark
Mission: Shark Longline Survey Geographical Area: Southern Atlantic/Gulf of Mexico Date: Tuesday, July 28, 2011
Weather Data from the Bridge
Latitude: 27.34 N
Longitude: -080.03 W
Speed: 1.50 kts
Wind Speed: 12.19 kts
Wind Direction: 140.99
Surface Water Temperature: 27.40 C
Surface Water Salinity: 24.04 PSU
Air Temperature: 29.50 C
Relative Humidity: 72%
Barometric Pressure: 1018.06 mb
Science and Technology Log Today we arrived at our first station. It took us a while (3 days) to get here. Where is here? We are off the eastern coast of Florida right now.
You might be wondering… how do you catch a shark? In order to collect data on sharks, the ship slowed down so that we could set bait and begin to fish. The bait was big chunks of mackerel placed onto hooks. (Mackerel is just one of many fish sharks enjoy eating). Then we attached a tag (with an identification number) to each hook and released it from the stern (back) of the ship. All together, there were 100 baited hooks on a monofilament line that was 1 nautical mile long (equal to 1.15 miles). The baited hooks were released every 60 feet. Then we waited one hour before hauling in the line. This kind of work takes teamwork – one person to get the tag ready, one person to attach the tag to the baited hook, and one person to make sure the line is going out steadily. There is also one person collecting data on a laptop about the tag number that went out. Pretty much, the job can’t be done without people working together.
One hour later, we began to haul in the line. Out of 100 hooks, we caught 4 sharks. There was one Atlantic sharpnose and three hammerheads. If the shark was small enough, we brought it aboard the deck to take measurements. If it was too large to bring in by hand, we used a cradle, which is basically a net with a strong frame that sits off the side of the boat. We measured the length in millimeters using a measuring board, mass in kilograms using a spring scale, gender (using our eyes), and took a tiny sample of the dorsal fin tissue (which helps with DNA identification). All of this is done within minutes. The shark data is collected very quickly so that we can get it back into the water as soon as possible.
At our second station today, we caught many Atlantic Sharpnose and one Goliath Grouper. The grouper was enormous – 300 pounds! (as you can see in the picture below). We also tagged a shark using something called a Roto-tag. This small yellow device is attached to the middle of the dorsal fin and has identification information and a phone number to call if the shark is found. The shark was also injected with an antibiotic. It is deposited in the vertebrae as a fluorescent marker. The number of growth rings deposited in the vertebrae after the marker help scientists determine the shark’s age. Kind of like rings on a tree trunk.
Try your luck with this math problem (keep your summer math rust-free!):
We cut up one whole mackerel into 4 pieces and place each piece on a hook. There are 100 hooks. We set out a line of 100 hooks 5 times a day. We do this repeatedly for 13 days.
Personal Log At first I was a little hesitant to handle the sharks while they were on deck. But under the tutelage of our chief scientist, Mark Grace, I began to feel more confident (thanks Mark!) He showed me how to hold the shark by the tail while also holding the mouth closed. Once I got the hang of it, I really enjoyed it. After collecting data, I was able to release a few sharks back into the water and watch them swim away.
I had a hard time sleeping well last night because yesterday I took a 3 hour nap during the day to try to calm my stomach. But since my shift ends at midnight tonight, I’m sure I’ll fall asleep no problem.
I have been eating wonderful food cooked by our talented stewards (chefs). Some of our meals have included beef tenderloin, burgers, pork chops, biscuits, mashed potatoes…the list goes on (yes, there are some vegetables in there too!). Meal times are only scheduled for one hour, so if you know you will miss your meal due to a shift you can request that a plate be set aside for you. Of course there is unlimited cereal, snacks, sandwiches…and ice cream!
Now it’s off to bed after a long shift ending at midnight.
Species Seen Today: Atlantic Sharpnose Shark
Scalloped Hammerhead Shark
Mission: Shark Longline Survey Geographical Area: Southern Atlantic/Gulf of Mexico Date: Tuesday, July 26, 2011
Weather Data from the Bridge
Latitude: 27.90 N
Longitude: -086.42 W
Speed: 11.50 kts
Wind Speed: 9.10 kts
Wind Direction: 272.65
Surface Water Temperature: 30.10 C
Surface Water Salinity: 26.89 PSU
Air Temperature: 30.10 C
Relative Humidity: 64%
Barometric Pressure: 1011.94 mb
Science and Technology Log
We set off from Pascagoula, Mississippi yesterday at 3PM. We had a short delay in leaving due to some maintenance that had to be handled, but it wasn’t too long until we were underway. It turns out we will be motoring around the southern coast of Florida and up the Atlantic to reach our stations. This project’s mission is to monitor the variability in shark populations off the Atlantic coast and Gulf of Mexico. We should begin setting line with baited hooks on Thursday. Each shark caught will be measured for length, mass, and sex. Some sharks will also be tagged in order to collect more data after their release.
The Oregon II has 30 people aboard, including crew, scientists and volunteers. The crew includes officers, fishermen, cooks, an electronics technician, engineers, and other NOAA personnel. In addition to the mission of the NOAA survey, there are volunteers who are performing their own research, such as studying the stress levels of sharks, shark reproduction, and identifying plankton species. The boat itself is a 170-foot vessel.
I’m having a great time on the ship and the people aboard are wonderful. Everyone has been very welcoming and willing to answer my (many) questions about nearly everything. I will be working the day shift when we reach our first station (noon to 12AM), which is great because I can sleep at night normally. I settled into my room which has bunk beds, a sink, and a shared bathroom/shower with the room next door. One of the officers, Sarah, gave us a tour of the boat, including three exercise rooms! I have yet to try them out, but I’m thinking it will be the ultimate test of balance to run on a treadmill while the boat is in motion. Since we have a few days (three) before reaching our first station, many of us have been watching movies (there is a big screen TV in the lounge), reading, and relaxing. I’m sure the work will pick up soon enough, so it’s nice to take it easy for a while. But I am eager to get started. I had a hard time eating dinner last night. For some reason, I lost my appetite. I don’t think it had to do with sea-sickness, but perhaps adjusting to the rocking motion of the boat. The seasickness patch I’m using is working out well so far.
Today we practiced a fire and emergency drill (abandon ship). During an abandon ship drill, we put on our survival suits. They are big, orange, and take some practice getting into! The suits will keep you warm and buoyant in water. Each one has a strobe light and whistle. When I finally got into mine (with some helpful tips from others) I looked like a big orange Gumby. That is why the survival suits are also called “Gumby” suits.
Something to Think About
A ship out to sea has to be self-sustaining. We are like our own floating city. How do we get fresh drinking water? Where does our waste go? How do you feed 30 people 3 times a day for 16 days? These are questions you may or may not have wondered about…well I’m going to tell you anyway! The boat makes its own fresh water through a process known as reverse osmosis. This removes salt and other molecules from water to make it usable. It gives us drinking water, and water to wash with (for showers, laundry, dishes, etc.) The heads (or toilets) are flushed using salt water. This makes sense because we have an unlimited supply! We have a marine decomposing system that adds bacteria to break down human waste before releasing it to sea. Food scraps? Also sent out to sea to decompose or be eaten. Garbage? Well…we have to hang on to that for the entire trip. This really makes you think about trying to reduce the amount of garbage you produce.
NOAA Teacher at Sea
Maureen Anderson Aboard NOAA Ship Oregon II July 25 — August 9, 2011
Mission: Shark Longline Survey Geographical Area: Southern Atlantic/Gulf of Mexico Date: July 15, 2011
Hello! I’d like to introduce myself. My name is Maureen Anderson and I teach middle school science at MS442 in Brooklyn, NY. In one week, I will be leaving for my NOAATeacher at Sea trip aboard NOAA Ship Oregon II. I’m very excited to be a part of this survey! I don’t have a very strong background in science (I have 4 years of teaching experience – 3 in math and 1 in science), so I’m eager to learn as much as I can and share it with my students and community when I return.
Here’s a little bit of information about the trip. I will be helping scientists survey various fish species in the Gulf of Mexico, with a focus on sharks and snapper. Our boat leaves from Pascagoula, Mississippi on 7/25 and returns to Mayport, Florida on 8/9. We will cruise from one station to another to do hauls and sort through our catch. In this way, scientists get an idea about how many species are in this area and the overall health of these species.
A lot of people have already told me many shark jokes, or given me tips for how to handle a shark. But guess what? I won’t be dealing with sharks in the water directly (no diving on this trip). My students ask me tons of questions about sharks. While I sometimes encounter them during scuba diving, I really don’t know too much about them. So I’m looking forward to learning more about how to identify different shark species and finding out about the their overall health in this area of the world. Overall, I’m also eager to learn about how everything works on a ship, and about the different kinds of science jobs and careers of the crew.
I have never slept on a boat before, so I’m hoping that I have no problem adjusting to life at sea for 16 days. I have a ready-to-go seasickness patch just in case… Other than that, I am excited and eager to learn!
I will aim to make a blog post about 3 times a week, so please check back. Feel free to post your comments, feedback, and questions along the way!