NOAA Teacher at Sea
Aboard NOAA Ship Oregon II
July 25-August 8, 2015
Mission: Shark Longline Survey
Geographic Area of the Cruise: Atlantic Ocean off the Florida and Carolina Coast
Date: July 29, 2015
Weather Data from the Bridge:
Wind speed (knots): 9.2
Sea Temp (deg C): 29.6
Air Temp (deg C): 28.7
Yesterday was the first full day of sampling. We were off the coast of Miami, FL and it was relatively shallow. I’m not sure how many sharks I expected to see on my first day, but certainly not the 80 + that we did catch!
Science and Technology Log – A, B, C’s of Fishing for Sharks
Kristin Hannan preselected our stations following a random stratified approach. Sampling stations have A, B, or C designations, depending on the depth (A is more shallow than B or C). The night crew went on duty at midnight and completed one station yesterday morning. We completed three stations during our shift yesterday and three more today.
The bridge lets us know when we’re 30 minutes from our station, and we begin preparations. We bait the hooks with mackerel 20 minutes ahead of time.
When we get to the station, the longline is fed out from the stern of the ship and extends one mile. A
marker, called a high flyer, is attached to the beginning of the line. One hundred baited gangions are attached to the line at intervals after which another high-flyer marks the end of the line. The ship then returns to the starting point, the line is hauled in and the fun begins. If there is a shark on the line, the deck crew fisherman calls out “Shark On!” That’s the signal for someone from the science group to step up and take the shark, remove the hook and collect data.
The following data collected is collected for all sharks:
- Precaudal Length: Nose to base of tail
- Fork Length: Nose to fork of tail
- Natural Length: Nose to tail
- Total Length: Nose to end of tail when extended manually
- Weight (Kg)
- Sex Determination
Tag numbers and tissue sample collection is also noted if applicable.
Early morning haul back by the night shift. Video taken from the highest point on the ship.
Most of the sharks caught were small enough to bring up and hand to the science team. We use a wooden measuring board to determine lengths. Those that were a bit larger were brought up on deck by the fishermen and they required multiple handlers to collect data.
Very large sharks had to be measured with the help of a cradle and hoist. The cradle is lowered to water level and large sharks are coaxed onto the cradle using the hook and line they are still attached to. A hoist brings them to deck height for assessment. Deck Operations Crew manages all shark retrieval and determines when is safe for us to proceed.
Most of the sharks that we’ve caught have been Atlantic Sharpnose. This shark is relatively small (adults average 0.85 M) and are found in shallow Atlantic coastal waters from New Brunswick down into the Gulf of Mexico, and even off the coast of Brazil. They are known by at least 8 common names in different regions. My Biology students would recognize this as a good example of why it’s important to use agreed-upon scientific names for scientific research. The scientific name for this species is Rhizoprionodon terraenova. It has a long snout (longer than the width of the head) and most adults have a few white spots on a gray body.
Sharpnose mature relatively quickly and can begin producing offspring within two years; also, they can have up to 5-7 pups at once. These are major factors contributing to the abundance of this species. In comparison, larger sharks may take up to 15 years to reach maturity and typically have fewer offspring in each brood.
Our catch also included one Blacknose (Carcharhinus acronotus) and multiple Scalloped Hammerhead (Sphyrna lewini), Nurse (Ginglymostoma cirratum) and Spinner sharks (Carcharhinus brevipinna).
Larger specimens were brought to deck height using a cradle, for weight, size, and sex determination, and were lowered back into the water after being measured and tagged.
If your interests tend toward science mixed with heavy machinery, skilled fishing, robotics or electronics, perhaps one of the following careers is for you.
Tim Martin: Chief Boatswain
As the Chief Boatswain, Tim Martin is responsible of all activities that happen on deck and he maintains constant communication with the bridge during all operations. Tim came to NOAA fisheries with a wealth of experience gained while serving in the U.S. Navy and later as a commercial fisherman in the Pacific Northwest. He was initially classified as a “Skilled Fisherman” with NOAA and has worked his way up to Chief Boatswain.
He and his group set and retrieve the longline. They also run all of the heavy deck equipment, such as the cranes that are used to position the shark cradle for large sharks and the CTD (water Sampling device). The Chief Boatswain is also responsible for training new crewmembers and maintaining ship supplies. In addition, Tim has earned Dive Master Certification through the NOAA Diving School, considered to be the best civilian diving school in the US.
When asked what keeps him going, Tim is very clear that he believes the work that NOAA Fisheries does is very important, and he is proud to be able to use his expertise to support NOAA’s efforts. This satisfaction somewhat tempers the challenges of the job which include being at sea for at least 6 months of the year, and constantly being in a training flux. Tim feels a strong bond with his crew and there is a clear sense of mutual trust and respect among them.
Ken Wilkinson: Electronic Technician (Supreme), NOAA Fisheries Engineering Unit
Ken has been with the Engineering Unit of NOAA Fisheries for 26 years. The mission of his Unit is to
support NOAA Fishery research by developing innovative technology. Ken always wanted to work on the water and he initially studied Marine Biology in college, but he migrated toward electronics. His work allows him to combine two great interests. His work takes him to sea 50-80 days each year.
A major focus of the electronics unit is to support the Reef Fish program. Trawling nets and longline apparatus will damage reef systems. In order to assess reef fish populations in a non-invasive way, Ken and his group work a number of Remotely Operated Vehicles that capture still and moving images that can be used later to determine abundance and species diversity. Ken’s unit has also developed a device called an Autonomous Underwater Vehicle (AUV). This programmable instrument scans the sea floor using lasers and data collected is used to develop more accurate sea floor maps.
New device: Kennenator 5000 Dual Laser
Ken is on board the Oregon II testing his new device that can be used to assess the size of large sharks without bringing them to deck height. Ken’s device has two lasers set at a fixed distance from one another. The beams are directed toward the shark while it remains at the surface of the water. Various measurements can be extrapolated from the laser measurement. Large sharks caught on the longline survey are typically brought to the surface in the cradle for assessment. Cradle use is preferred as it allows tagging and tissue sample collection and sex determination. However, there are situations when this is not possible such as when poor weather conditions develop which limit sling operations, and some small vessels are not equipped with sling equipment.
The fast pace of the haul back at early stations was jarring. I stepped up when “Shark On” was called and a writhing Sharpnose was thrust into my hands. The first task is to get the hook out of the shark’smouth and this is no small feat. The circle hook is designed is to reduce the chance that the shark will swallow the hook or get hurt by it, but getting these hooks out of the mouth without hurting the shark requires technique. There will be plenty of opportunities to get the hang of in the next week.
A highlight of this first day was getting up close to a 2 meter long Scalloped Hammerhead brought to the surface in the cradle. I was able to feel its head, observe its eyes, and place an identification tag near its dorsal fin before it was lowered back into the water.