Ragupathy Kannan: Petrels to Pilot Whales, August 30, 2019

NOAA Teacher at Sea

Ragupathy Kannan

Aboard NOAA Ship Gordon Gunter

August 15-30, 2019

Mission: Summer Ecosystem Monitoring

Geographic Area of Cruise: Northeast U.S. Atlantic Ocean

Date: August 30, 2019

Weather Data from the Bridge

Latitude: 40.72218
Longitude: -69.45301
Water temperature: 19.8 degrees Celsius
Wind Speed: 5.25 knots
Wind Direction: 87.06 degrees
Air temperature: 23.2 degrees Celsius
Atmospheric pressure: 1006.85 millibars
Sky: Cloudy

Science and Technology Log

We’ve had a flurry of whale sightings as we passed over the famous Stellwagen Bank National Marine Sanctuary. It’s a small underwater plateau in Massachusetts Bay flanked by steep drop offs. Nutrients from the depths rise up by upwelling along the sides, feeding phytoplankton in the shallow light-abundant waters, and this creates perfect feeding habitat for whales.

Much of my time aboard this ship has been on the flying bridge (the highest point of access for us on the ship) scanning the seas for marine vertebrates. I have basically been an extra pair of eyes to assist my colleagues Chris Vogel and Allison Black, the seabird observers on board. From nearly 50 feet high above the water, the flying bridge gives nearly unimpeded 360° views of the horizon all around. I call out any vertebrate animal seen—fish, birds, reptiles, or mammals. Chris and Allison enter all of our data in a specific format in a software program called SeaScribe.

To calculate densities of each species, we need an estimate of how far the animal is from the ship for each sighting. For that we use a rather low tech but effective piece of equipment. The pencil!

This is how it works. The observer holds the pencil (photo above) upright with arm outstretched, aligning the eyes and tip of the eraser to the horizon (see photo below), and simply reads the distance band (Beyond 300m, 300-200, 200-100, or 100-50m) in which the animal is seen. Thanks to some fancy trigonometry, scientists found a way to estimate distance by using the height of the observer’s eyes from the water surface, the distance from the observer’s eyes to the eraser tip of the pencil when it’s held upright with arm outstretched, and the distance to the horizon from the height of observer’s eyes above water. I’ll spare you the trigonometric details but those curious to learn more can find the paper that introduced the technique here.

Kannan and range finder — Here I am using the range finder

Seabirds are a challenge for a rain forest biologist like me. They move fast and vanish by the time you focus the binoculars! And the fact that the deck heaves up and down unexpectedly adds to the challenge. But slowly I got the hang of it, at least the very basics. I’ve recorded hundreds of shearwaters, storm-petrels, boobies, gannets, jaegers, and skuas. Whales (sea mammals) seen include Finbacks, Humpbacks, Minkes, and Pilots. I am hoping to see a Right Whale but I know that the odds are against me. Time is running out, both for our voyage, and for them. Unfortunately, only a few 100 are left and the ocean is huge—the proverbial needle in the haystack. Chief Scientist Harvey Walsh tells me that this year so far, 8 Right Whales have died due to accidental collisions or net entanglements. Sadly, the future looks bleak for this magnificent animal. (More on Right Whales at the end of this blog).

Great Shearwater ebird — Great Shearwater is one of the most common seabirds we have recorded. This bird nests only in a few islands in the South Atlantic Ocean and wanders widely. Photo by Derek Rogers, from ebird.org

I note that marine vertebrate biologists are good at extrapolating what little they can see. Much of their subjects are underwater and out of sight. So they have become good at identifying species based on bits and pieces they see above water. All they need often is a mere fleeting glimpse. Sharks are told by the size, shape, and distance between the fins that stick out, sea turtles by the shape and pattern on their carapace (top shell–see photos below); whales based on their silhouette and shape of back; and Molas based simply on the fact that they lazily wave one large fin in and out of the water as they drift by. (I thought it was the pectoral fin they waved, but it’s actually the massive dorsal fin. I’ve noted that the pectoral is rather small and kept folded close to the body).

leatherback sea turtle A. Black — A fleeting glimpse is all that is needed to identify a Leatherback Sea Turtle, thanks to its diagnostic longitudinal ridges (Photo by Allison Black).

shark fins — We’ve had several shark sightings such as this. The size, shape, and the relative locations of the fins indicate that this could be a whale shark (Photo by Allison Black)

Scientists can identify individual humpbacks based solely on the indentations and color patterns on their tail flukes. In effect, each individual animal’s tail fluke is its unique fingerprint. Since the tail fluke is often seen when the animal dives from the surface, scientists have a huge photographic database of humpback tail flukes (see photo below). And they track individuals based on this. My ecology students should know that scientists also estimate populations based on a modification of the capture-recapture method because each time an individual’s fluke is photographed, it is in effect, “tagged”. We do a nice lab exercise of this method by using marked lima beans masquerading as whales in my ecology lab.

humpback tail flukes — Researchers use variation on humpback whale flukes to identify and track whales (from Wildwhales.org)

Finback whale — Finback Whales are easily identified by the fin on the back (From aboutanimals.com)

Career Corner

I spoke with Allison Black, one of our seabird observers on board.

Q. Tell us something about yourself

A. I really love seabirds. I’m fortunate to have been able to do my Master’s work on them and observe them in their natural habitat. I have an undergrad degree in zoo and wildlife biology from Malone University in Canton, Ohio.

Q. You’re a graduate student now in which university?

A. Central Connecticut State University

Q. What’s your research project?

A. I conducted a diet study of Great Black-backed and Herring Gulls on Tuckernuck and Muskeget Islands, Massachusetts.

Q. You have done these NOAA seabirds surveys before?

A. Yes, this is my third.

Q. What happens next, now that you are close to finishing your Masters?

A. I’m looking for full time employment, and would like to work for a non-profit doing conservation work. But until the right opportunity arises you can find me on a ship, looking for seabirds and marine mammals!

Q. What’s your advice to anyone interested in marine science?

A. I had a major career change after I did my undergrad. I thought I’d always be a zoo keeper, which I did for about two years until I decided that birds are really my passion, and I needed to explore the career possibilities with them. To focus on that avenue I decided to return to graduate school. So I would encourage undergrads to really find what drives them, what they’re really passionate about. I know it’s hard at the undergraduate level since there are so many fields and avenues under the Biology umbrella. And it’s OK if you haven’t figured that out for a while. I had a real change in direction from captive wildlife to ornithology, and I’m here at sea in a very different environment. I’m so glad I did though because following my passion has opened up some exciting avenues. I’m lucky to be getting paid to do what I really love right now. So grab any opportunity that comes by. It’s never too late to evaluate your career path.

Personal Log

My feelings are bitter-sweet as this wonderful 16-day voyage nears its end. My big thanks to NOAA, the ship’s wonderful command officers and staff, our Chief Scientist Harvey Walsh, and my colleagues and student volunteers aboard for making the past 2 weeks immensely absorbing. Above all, kudos to the ship’s designers, who have clearly gone out of their way to make life aboard as easy as possible. In addition to the unexpected luxuries covered in my previous blogs, there is even a movie lounge on board with an impressive DVD collection of over 700 movies! Yesterday I saw our student volunteers play bean bag toss on the winch deck. Yes, you can throw darts too. The ship’s command even organized a fun sea animals-bingo game one evening, with winners getting goodies from the ship store (see below).

The engine rooms tour

As part of our grand finale, we were given a tour of the engine rooms (which are usually off bounds for non-crew members) by our genial First Engineer, Kyle Fredricks.