2/19/2014 – Marine Mammal Observations

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Tasha writes:

When you think about Antarctica, what first comes to mind? I’ve had quite a few people ask me about penguins and polar bears when I first told them I was traveling to Antarctica. Truth be told, polar bears only roam around the Arctic, and penguins only frolic here in the south. The penguins find company with the seals and whales that also live in the Antarctic, or sometimes become dinner for them. These guys are the token mascots for every image that most people conjure of Antarctica. They are also heavily protected under the Marine Mammal Protection Act so part of our job when we conduct science is to ensure our science minimally impacts wildlife.

Adelie penguins in "flight"

Adelie penguins in “flight”

We worry most about our impact on marine wildlife when we conduct seismic surveys. The seismic guns deliver a low energy pulse into the water column, which may have the potential to negatively affect marine mammals if they are exposed to 180 decibels or more in the water. For that reason we have two qualified marine mammal observers, Andrea Walters and me, on-board to ensure we do not injure wildlife during our seismic gun operations. Our science party must also conduct marine mammal observations (MMO) when the ship is breaking ice in order to record how many marine mammals we might be exposing to our operations and to record how icebreaking may alter their behaviors. Icebreaking potentially produces quite a racket that can expose animals within 12 nautical miles to 120 decibels underwater. MMO during icebreaking is a new practice so the data we record will be extremely helpful in understanding how icebreaking impacts the animals.

Sometimes this gets a little noisy

Sometimes this gets a little noisy

With only two trained marine mammal observers on-board, conducting observations for seismic and icebreaking while also getting a few hours of sleep a day would be nearly impossible on many days. Therefore, when we first set out on the cruise Andrea and I conducted marine mammal observer training for the science party so that they could rotate in for icebreaking MMO duty as needed. Many of the scientists on-board were unfamiliar with Antarctic species before this trip, but with the expertise of the mates in the beginning, reading of the wildlife identification aids, and a few sightings under their belts, most of them have become comfortable with species identification.

Now, during their daily watch the newly-trained observers among the science party may come up to the bridge for an hour or two to stand MMO during ice breaking operations. The watch seems to be something that most of them look forward to; it allows watch-standers to take a short break from watch down in the lab and come up into the daylight on bridge to enjoy the beautiful scenery and interesting wildlife we come across.

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Seismic operations typically last for up to 16 hours, and Andrea and I stand two 4-hour watches each during that time. We must report any seals or whales within 600 meters of the seismic guns and shut down seismic operations if they come within 100 meters of the guns (the 180 decibel range). We initially stand a 30-minute pre-watch together before seismic operations begin to ensure there are no animals within 100 meters of the ship. Then we rotate individually through our 4-hour watches. As seismics are conducted in open water away from sea ice, we don’t come across many mammals; actually, so far, we have been lucky to not see a single mammal during seismic operations and have not needed to shut down operations once.

Was this photo planned? No, it was a total fluke.

Was this photo planned? No, it was a total fluke.

During MMO, we record about 25 pieces of information for each animal sighting during icebreaking and about 35 during seismic operations. This information will be sent to NOAA and used not only to understand how/if we are impacting marine mammals, but also for documenting the general Totten mammal community; we are the first to come into the Totten and record marine mammal populations. We record everything from where, when, and what species we came across, to it’s initial behavior and reaction to the presence of the vessel.

Jamin (with clipboard) explaining the ELOG

Jamin (with clipboard) explaining the ELOG

All of the information is essential, but we recognized early on that during times when a new seal sighting comes up every 30 seconds (during icebreaking), recording so much information for each sighting becomes nearly impossible in a written log. Luckily, Jamin Greenbaum, a graduate student who works on bathymetric mapping tusing aircraft-based geophysics, came to our rescue. He brilliantly created an ELOG (a web-based data logging program) that automatically fills in ship information (e.g. ship speed, course over ground, wind, etc.) and features automatic pull-down menus to make the recording process more efficient. This has improved the data recording process tremendously for MMOs.

So what kinds of animals do we come across out here? Well, Adelie penguins tend to be the most common animals we come across. Reminiscent of large black and white footballs, we typically see them alone or in small groups, milling around on their own private ice islands. They move around in awkward, chaotic disarray that resembles something you might expect from the Three Stooges. Their waddling with wings outstretched behind and graceless belly flops into slides across the ice always draws endless laughter and adlib narrations from observers on the bridge. We also see lone Emperor penguins from time to time who typically seem to take little notice of our passing. As our MMO label suggests, however, we do not record penguins in our logs.

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Most days as MMO’s, we observe few animals that count as “Level B takes” (marine mammals we may have harassed with our operations), but on a few different occasions on this trip, we have crossed through the ice along the continental shelf on our way into the polynas (at Mertz and Totten) and have seen multitudes of marine mammals. Gene accurately described this phenomena, “You go for days without seeing a single animal then suddenly the entire ecosystem comes out and you scramble to keep up records for all of them.”

A crabeater seal bellows a warning at the large orange intruder

A crabeater seal bellows a warning at the large orange intruder

Typically, we see mostly crabeater seals on those days, but we have also seen Weddell seals predominantly within the Moscow University/Totten polynya. We occasionally run across a creepy reptilian-looking leopard seal with its threatening, blood red mouth and have seen a Ross seal on one occasion as well. We tend to see whales in open water out on the continental shelf. Humpback and minke whales pop up the most, but others we might expect from time to time include sei, fin, blue, sperm, killer, and long-finned pilot whales; hourglass dolphins; and spectacled porpoises. For me, my ultimate goal is to spot a blue whale while up on the bridge. Spotting any of the animals, however, never gets old, and I look forward to many more watches before the conclusion of our cruise.

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