Humpback whale lunges in Marguerite Bay
Zach Swaim and I have just returned from a 6-week excursion to the deep south, to further incorporate and expand marine mammals studies into the epic Palmer Long-term Ecological Research (LTER) Program during its annual cruise along the Western Antarctic Peninsula. Through a combination of visual surveys, biopsy sampling and opportunistic acoustic recordings, my overarching goals for this cruise were to 1.) better characterize the density, distribution and stock structure of marine predators within the LTER study area and 2.) Develop protocols for efficiently incorporating visual, photographic, biopsy and acoustic sampling into the LTER cruise.
Ultimately, I wanted to fill every nook and cranny of negative space on the timeline of this cruise with whale work – meaning that, when the ship was not being 100% utilized by the standard LTER science ops, I wanted turn those unused percentage points into useful marine mammal data. Below you will find a brief overview of the cruise with some details on how well things went with our whale work. In a word though, I’d have to describe it as awesome.
Firstly, I have to say that we worked with some of the most amazing people I have ever had the chance to sail with. The cast of regulars on the LTER project – Hugh Ducklow, the PI from Columbia; Oscar Schofield from Rutgers, Debbie Steinberg from VIMS and Donna Patterson/Bill Fraser from PORG really made us feel welcome as we boarded and set up shop on the ship. Their support of our efforts was integral in getting our work done. Perhaps most interestingly, a duo of filmmakers/photographers (Dena Siedel from Rutgers and Chris Linder from WHOI) constantly captured our efforts for a new movie funded by NSF.
I also wanted to thank the rest of the scientists on the cruise, who helped us collect our data both on the big boat and in the zodiacs. In particular, Jen Mannas, Josh Stone and Cameron Rutt were great support spotting whales on the bridge. Thanks!
We started off in Chile aboard the ASRV Laurence M. Gould (a familiar ship from our first MISHAP cruise in 2009) and scooted across the Drake Passage in fine form – hardly broke 20 knots of wind on that crossing! We surveyed for whales down through the Gerlache Strait, up the Bismark Strait to Palmer Station, where we unloaded some people and gear, loaded some other people and gear, and then headed out on the LTER cruise itself.
The Gould at Palmer Station
The LTER cruise is now a combination of nested, grid-based mesoscale oceanographic and ecosystem sampling along the shelf of the WAP coupled with other fine-scale, more adaptive “process study” sampling that occurs proximate to penguin colonies and undersea canyons. The majority of the work occurs over the continental shelf of the WAP and the grid of sample stations extends from the 600 line at Palmer Station (about 65 degrees south) to the -100 line near 70 degrees south around Charcot Island. A great description of the LTER grid is available here.
The science conducted on the LTER cruise spans physics to top predators, with 24 hour operations that use the full suite of scientific gear available for this type of work: net sampling, bioacoustics, CTD casts, ocean gliders – if you can name it, it was dipped, soaked, dropped, towed or otherwise deployed/recovered on this cruise. The primary marine predator work has focused on Adelie penguin colonies at three locations: Anvers Island/Palmer Deep; Avian Island and Charcot Island. We were aiming to expand that to cover the guild of marine mammal krill predators in the region – cetaceans and pinnipeds.
The marine foodweb of the west Antarctic Peninsula - Credit I. Heifetz, Rutgers University
During the cruise, Zack and I were a continual presence on the bridge of the Gould, conducting standardized line transect sampling for marine mammals or collecting less structured opportunistic sightings whenever possible. We used digital SLR cameras with some big glass to capture photos of humpback whale flukes from the Gould bridge wings whenever we could, but mostly we waited for opportunities to splash the zodiacs and get up-close-and-personal with humpbacks for photos and biopsy sampling. We collected sightings on the grid lines as we moved south from Palmer Deep, and launched the zodiac frequently at each of the process study regions for our photo and biopsy work. A nice blog that describes our biopsy work can be found here.
The raw fruits of our labor were impressive: 45 biopsy samples of humpback whales, 331 sightings of groups of marine mammals, including sighting over 1800 crabeater seals in a 20 sq km region in the vicinity of Charcot Island. Some initial figures are included here to illustrate what we got done.
Species counts for LTER cruise
Sighting locations of marine mammal groups
We worked hard, but had a lot of fun too. Some highlights for me: encouraging our zodiac driver to back us out of a humpback bubblenet before we got the Jonah treatment and – top of the heap – playing soccer at Rothera Station against the Brits. We lost, but how awesome is it that I can now add to my CV the fact that I have represented the U.S. in an international soccer match!
Photo gallery of pictures from the latest Palmer LTER cruise along the Western Antarctic Peninsula
I’m finally back at the Duke Marine lab, after a series of adventures in Massachusetts that don’t really need dwelling on. It’s great to be back – seeing family, friends and getting on with things that have been waiting for some attention for a bit.
Andrew Westgate loves the Long Eddy!
The Long Eddy field season was a fantastic success. We got two tags out, which may seem like a small number to many. Keep in mind however, we were tagging fin whales at their most erratic – as they exploit discrete patches of prey within an island wake system. This is truly a great success, and paves the way for future proposals. We’ve surveyed the wake extensively now with the echo sounder system, providing essential baseline data on how the “middle” portion of the food web coalesces and dissipates each tidal cycle. We’ve also captured the physical properties of the water column within the Long Eddy with CTD casts.
I’d like to finish up by thanking the field team: Julia Burrows, Jerry Moxley, TJ Young and Susan Heaslip. Ari and I are really grateful for your help with the project.
I’d also like to thank Heather Koopman, Rob Ronconi and Andrew Westgate from the GMWSRS for their boat skills and logistical help – we could not have done it without them.
We also could not have done it without the help of Ken Ingersoll and his big truck. Thanks Ken!
When we’ve had a look at the data we’ll post a roundup for this year as well, stay tuned.
Phocoena surveying the Long Eddy
The weather was great from Tuesday through Friday, calm seas, light wind, and sun, but then took a turn for the worse to more typical Grand Manan weather…wind and fog. It was blowing a good 25 knots on Saturday, keeping us onshore, but Sunday morning, we awoke to no wind and fog. These conditions weren’t good for the tagging boat because they need calm weather and clear skies to spot whales, but the prey mapping boat can operate in fog since what we are looking for is all below the ocean’s surface. We decided to make the most of the weather and head out to calibrate the echosounder. We went to a more protected area on the eastern side of Grand Manan and tied up our boat. We then hung a perfectly rounded sphere of known sound backscattering strength under each frequency of the echosounder (38 and 120 kHz). We moved the sphere around attempting to cover the entire beam of the echosounder and recorded data during this process.
Here’s an image of the final product. Red dots are where the values for backscattering strength of the sphere are above expectations, and blue dots are values below expectations. The green dots are those closest to the center axis.
Things went surprisingly smoothly during the calibration, in large part because TJ and I had done a practice calibration at the dock the day before. Of course, the day wouldn’t have been complete without some type of echosounder malfunction. Just as we were finishing up calibration of the 120 kHz echosounder, the program decided to crash and we had to redo the calibration. We did prevail in the end though, completing a quick second calibration just as the fog had burned off.
The tagging team met us out on the water and began to search for whales during flood tide in the afternoon. We (prey sampling team) began to run line transects. In the eddy Conditions weren’t as nice as they were the week prior, and it was quite challenging to deploy the towfish (that’s what we call the device we with the echosounder in it, see the picture of it on the deck of the boat) as we were rocking and rolling broadside to the chop in our small boat. We managed to survey three lines before we called it a day. The tagging boat was unsuccessful in finding a fin whale, and only saw two minke whales and a handful of porpoise all afternoon. We do always have bird sightings, and the Greater Shearwater is the most common bird we see while we are sampling in the eddy.
Our lack of fin whale sightings was a reminder that despite working in a very predictable system (regular tides, prey aggregations, and marine mammal predators), unlike physics, animals are unpredictable and are not always around when you expect them to be.
I would have to say what might be the most exciting thing that happened all day was when we got a call on the radio that Jerry, our new whale tagger, had unintentionally taken a swim in the cold waters of the Bay of Fundy. According to Jerry, he was trying to rescue a baby harbor porpoise who was stuck in a bucket, all the while fighting off a killer whale who was trying to have the porpoise calf for diner…but we all know what really happened. He was in fact doing a good deed by collecting trash from the Bay – a bucket. The bucket, to his surprise, was filled with water and was heavier than he expected and simply pulled him over the side. He did manage to hang onto the boat, so was able to swing himself back in fairly quickly, but not before his self-inflating life jacket went off.
We wrapped up the evening with a delicious dinner with old and new friends at the Grand Manan Whale and Seabird Research Station. Stories were told of when our advisors (Dave Johnston, Heather Koopman, and Andrew Westgate) were graduate students patrolling the herring weirs for trapped harbor porpoise and drinks were shared among many. All in all, just another day of fieldwork in the Long Eddy….with many new stories in the making.
Grand Manan and the Long Eddy
The Long Eddy, situated on the northern tip of Grand Manan Island, is a beautiful and stimulating place, full of animals and energy. In a short span of minutes the ocean can change from glassy flat to boiling with upwellings and chop. A calm scene with a lone slowly-rolling porpoise changes into a cacophony of life – from krill to fin whales – in mere minutes. The predictable nature of the system, driven by unchanging physics, has long led people to this place for sustenance, scenery and science.
Let’s start with sustenance; it usually comes first. Indigenous peoples in the Bay of Fundy knew a lot about the Long Eddy and how it worked – it provided predictable access to an important resource – porpoises. In the late 1800s, porpoises were extremely valuable in the new currency-based economy faced by the Passamaquoddy Indians living on and near Grand Manan. Their meat was consumed and traded, but they were hunted mainly because the little animals were so rich in valuable oil. This oil was useful for light and lubrication, and mainland Passmaquoddy tribe members would canoe across to Grand Manan from the Campobello Island region to hunt porpoises in the Long Eddy and render them for oil on Indian Beach, a rocky beach on the northwest side of the island. These hunts were executed from canoes with spears and primitive rifles, and C.C. Ward published an excellent article in the October 1880 issue of Scribner’s Monthly that describes the process. The image at left illustrates the hunt being conducted in the Long Eddy, and those familiar with the island will recognize the Bishop headland in the background, with Fish Head rising out of the fog in the backdrop.
“Where are we going now, Sebatis?”
“Goin’ away long eddy, off northern head.”
“Is that a good place for porpoises?”
“Sartin; always on rips very good place; you see, plenty mackerals, herrin’s, and all kinds fishes in eddies and rips; very good feedin’-ground for porpusis, you see.”
The eddies or rips alluded to by Sebatis were caused by the obstruction offered by projecting headlands to the ebb and flow of the tide…
C.C.Ward-1880
The Passamaquoddy knew how the Long Eddy worked, perhaps best illustrated by this quote from the Ward 1880 paper, relating a discussion between Sebatis, a Passamaquoddy tribe member and the author:
“Where are we going now, Sebatis? ”
Goin’ away long eddy, off northern head.”
“Is that a good place for porpoises?”
“Sartin; always on rips very good place; you see, plenty mackerals, herrin’s, and all kinds fishes in eddies and rips; very good feedin’-ground for porpusis, you see.”
The eddies or rips alluded to by Sebatis were caused by the obstruction offered by projecting headlands to the ebb and flow of the tide…
A fin whale cruises the Long Eddy
Let’s move on to scenery. Whale watching is now a lucrative world-wide industry that champions the non-consumptive use of cetaceans. The industry focuses on the aesthetic value of whales, channeling John Muir’s original visions of the value of nature. Whale-watching is an important industry on Grand Manan and in other coastal communities in the lower Bay of Fundy, with several operators taking people offshore to see right whales, humpback whales, fin whales, minke whales, ubiquitous harbor porpoises and other big, beautiful ocean creatures. Several operators frequent the Long Eddy, some from Grand Manan and others from communities in Passamaquoddy Bay. Much like the original Passamaquoddy peoples crossing from the mainland to Grand Manan to hunt porpoises, mainland whale-watchers speed across the Grand Manan Channel in catamarans and zodiacs to watch porpoises, minke whales and fin whales dive and lunge amidst the aggregations of herring and krill, as shearwaters and other seabirds look on. Speaking from experience, it doesn’t get old. The magnitude of life in the Long Eddy is incredible, and aesthetically speaking, there are very few places on earth that can match it.
The Long Eddy swirls behind Grand Manan, captured from space by RADARSAT synthetic aperture radar
How about science? The Long Eddy is controlled by tides, constrained by eternal physics. As a marine scientist and field biologist who studies marine mammals, a place like the Long Eddy is extremely compelling. The system sets up and dissipates twice a day, everyday – a predictable system so prominent that you can see it from space. Can you think of many places where you are guaranteed to see 200 harbor porpoises, 5 minke whales and 2 fin whales all within a 5 km square box twice a day? In the late summer and fall, this is routine for the Long Eddy. Because it is predictable, and a short ride from the wharf, the Long Eddy is ideal for studies addressing questions of ecosystem organization and progression at fine scales, from tides to top predators. By combining visual observations with advanced telemetry and prey mapping, we can see how tidal energy helps entire food webs assemble and dissipate, and elucidate how predators and prey act and react amidst the tidal energies in the Long Eddy. We know only the basics of how the Long Eddy works, and there is much more to learn.
It’s been years since I’ve been fortunate enough to pass by the time on a flood tide in the Long Eddy, and it feels great to be back. I don’t need it for sustenance, but the scenery and science are a fine tonic.
I swear I looked down the long length of our 25-foot tag pole for what felt like minutes. The delicately positioned DTAG had disappeared from the end of the pole and the fin whale we had been chasing was descending below the water’s surface. Turning slowing, I holler back to the expectant eyes of the others on the boats and yell “Tag on, Garth.” I barely heard Dave, our intrepid PI and tag boat driver, yell back “Tag on, Wayne.”
They say you will never forget your first whale. But I swear I hardly remembered it. In the end, it was all a blur. But what I know was that I laid the DTAG squarely and firmly on the fin whale’s dorsal ridge, right in front of the dorsal fin. The team now had its second deployment of the DTAG onto a fin whale of the season. And, personally, it was exhilarating and instinctual.
Stepping back, the day had been fantastic thus far. Visually, the Long Eddy—the oceanographic feature off the northern end of Isle Gran Manan that we are studying—was going off: gulls and shearwaters bickering back and forth over easy forage; northern gannets elegantly dive-bombing prey from the shallow depths; harbor porpoises playing with the boats as if they were dolphins on a bow wave. Our prey mapping team was radioing in good news at every turn. To top it all, there were a few individual fin whales we had sighted throughout the study area. Time to lay the tag on.
There had already been a few hours of delicate dancing: the whale would surface, we would chase, the whale would descend, and we would wait for another surfacing. The courtship had grown old. But from the moment Dave gunned the engines, I knew we must make this one different. The animal was on opposite side of a seabird aggregation foraging on a shallow prey layer—the bobbing birds already too full of krill and herring. We had already missed one opportunity to tag, we had to make this one different. I spent most of the approach attempting to conjure more tag pole from my hands. The whale was just too far away… until it wasn’t. And that’s when I straight laid my first tag on a whale.
Tag on, Garth.
Today we sailed out to the Long Eddy and were greeted by unnaturally glassy and smooth seas, warm temperatures, and a clear blue sky. Sounds like a great day for research, doesn’t it? Hah! Let’s hear about what went on before we come to conclusions, yeah?
The Balaena, the appropriately-named tagging boat, spent a good chunk of their time around two distinct fin whales, one of which was the same individual tagged yesterday. The DTAG went on the pole and the team poised for a tagging attempt at multiple points throughout the day. However, the whales kept evading the boat and swam particularly fast to avoid being tagged–it was as if they knew we were coming! The whales certainly made our job hard as we could never predict where they would be next time we saw them surface. The boat got real close to the whale twice, but ultimately today was a no-go–the tag boat came back in just after high tide and called it a day. Some good news though: the tag boat saw their first Atlantic puffins today! They were quite cute and surprisingly awkward while in the water.
On the prey-mapping boat, the Phocoena, we took advantage of the calm seas and conducted two great line transects that had no electrical noise and showed a thick krill layer throughout. However, our luck quickly ran out as the adaptor to the computer charger failed to work, and the noise came back soon after. We pulled back to the harbour prematurely and did some more troubleshooting by doing every single combination possible with the wires, battery chargers, inverters, and more electronic stuff I don’t really know the name of. Couple of revelations today: the charger to the laptop cannot be anywhere close to any of the echosounder equipment and the batteries! What that means is that we have to run the echosounder with the laptop on battery power, because the noise is inherently linked with the charger. Well, as they say, the better the quality of data collected, the better the dissertation will be! So, we’ll try testing the limits of the computer’s battery life tomorrow and see what happens.
Overall, yet another learning experience, but I think we all benefited from it in some way or another! Nothing like a good reality check to get you back on track, right?
After about 10 yrs or so from when we first thought about doing it, today we put out a DTAG on a fin whale in the Long Eddy. It’s been a long time coming, and we are really happy to have cracked that nut.
Today was a great day. The winds were calm, the sky blue and there were critters everywhere. Ari was proud to note that on this fine day we encountered the four main species of cetaceans in the Bay of Fundy – fin whales, minke whales, harbor porpoises and right whales. Yup we hit all the highlights. It wasn’t just a great day for us – the GMWSRS basking shark team (lead by Andrew “Sparky” Westgate) got a tag out as well, and the ad-hoc bird team (led by Rob Ronconi) successfully worked up a number of birds. Simply put, today was awesomesauce.
Our team started off with right whales on the way to the Long Eddy. We came across a mother-calf pair about 1 mile off the Swallowtail lighthouse, stopped to take a few ID shots and then called in the sighting to the New England Aquarium researchers (relayed by the GMWSRS – thanks Rob!). This seemed like a good omen. After leaving the right whales behind we encountered several minke whales and hundreds of harbor porpoises as we entered the Long Eddy, but the fin whales remained elusive. The prey mapping team got a great start and mapped out the entire eddy as it formed, collecting a ton of echo sounder data.
We had several sightings of one fin whale (Getz again) early in the flood tide, but the animal was moving large distances during each dive. Finally, as we moved past mid-flood in the Long Eddy another fin whale joined the system and we moved in to strike. After several surfacings we finally found ourselves in the right spot for a tag attempt. We approached slowly and the whale evaded us. Shortly after however we caught the whale on it’s last breath before a dive and Ari popped on the tag about halfway between dorsal fin and blowhole, about 6 inches down on the right side of the animal’s back. Perfect placement – high up so that we got several beeps from the tag on each surfacing. We followed the animal for about two hours and as the flood tide finished up the tag popped off the animal near Fish Head.
Truth be told, it was a frustrating track because the animal moved great distances (making prey mapping around the whale difficult) and the tag seemed to have slipped down the side of the whale after the first hour, reducing the range at which we would get beeps from it on the receiver. The tag was shed by the whale after two hours – we quickly recovered it and then ran for home to get ready for tomorrow – the weather looks good and we are hoping for a replay. Stay tuned!
We’ve embarked on our field season in the Bay of Fundy, seeking to tag fin whales as they exploit prey aggregations in an island wake system on the northern tip of Grand Manan Island.
We’re only just getting started, and have had to hunker down for a day and a half for hurricane Irene-related weather. We did get one shakedown day to setup and test equipment, during which we also accomplished a quick recon of the Long Eddy and the critters that use it. The shakedown went well, with all equipment performing perfectly and we also collected some Photo-ID data on fin whales foraging in the feature. A good start!
We’ll have more updates soon!
Spring break at Duke is pretty much over, and it has been a busy time. Without classes to teach and with most of our research group at the Bio-logging conference in Hobart, Tasmania, it has been a great time to get some writing done. This week we polished off two papers on sea ice and seals in the North Atlantic, one of which is now submitted to the primary literature. The second will go in early next week.
Amidst this productivity, we also found out that Ari was awarded a National Geographic award for Dtagging blue whales and humpback whales in California, which will support some of Julia Burrows dissertation work.
Finally, we’ve also made great progress in the Digital Sea Monsters project this week, thanks to the programming team. With fewer distractions, we’ve been able to work out a significant number of bugs in the public portion of the app. Check out the layout on the Laysan albatross entry below…
[image title="Megafauna App: Laysan Albatross" size="large" align="center" icon="zoom" lightbox="true" autoHeight="true"]http://superpod.ml.duke.edu/johnston/files/2011/03/laysan_entry.jpg[/image]
Great news! The National Geographic Society is going to fund a short field season studying the foraging ecology of fin whales in the Long Eddy, an island wake system in the Bay of Fundy. This is a great opportunity for us to get back to Fundy.
This island wake system supports a variety of top predators (whales, porpoises and seabirds) and is highly predictable in time and space, making it – in many ways – an ideal natural laboratory for studying the foraging ecology of marine mammals. We hope to study how fin whales exploit this features during foraging using digital recording tags (drags) and a suitep of “ecosystem” observations made concurrently to provide the environmental context for observed behaviors. This will include measures of prey fields observed with active acoustics, ocean currents obtained by ADCP, and water properties assessed through CTD casts.
Island or headland wake systems are ubiquitous in coastal oceans, found pretty much wherever water flows past an obstruction. Because these systems are so common, understanding how marine predators such as fin whales use the Long Eddy can help us interpret patterns in their distribution and movements in other coastal regions. One of my key interests in this project is a deeper assessment of the utility of using studies that combine fine-scale oceanography with the movements and behaviors of top predators to delineate the extents of marine protected areas.
It also means that we will get the opportunity to further develop our nascent photo ID catalog of fin whales around Grand Manan Island. It should be interesting to see if the same whales we studied there almost a decade ago still use the feature as a foraging spot.
Can’t wait to get started!
[dropcap4 color="green"]O[/dropcap4]ver the past 26 hours my 8-core monster Mac Pro has been crunching numbers like never before. I’ve had it running a public domain climate modeling software package called EdGCM. This package, created by scientists at Columbia University, is based on a research-grade global circulation model produced by NASA called GISS II and has been developed primarily for educational uses in colleges, universities and even high schools. You can download a copy of the software for yourself here.
[image align="right" lightbox="false" link="http://edgcm.columbia.edu/"]http://superpod.ml.duke.edu/johnston/files/2010/12/20101201-052312.jpg[/image]My first simulation – extending 100 or so years into the future – was based on a very simple warming scenario included in the package as a demonstration. The model provides an amazing amount of output, and I’m just getting into some of the maps. The next step is to run it using parameters from the IPCC models currently under consideration.
The best thing about this package is that we can use it for an upcoming class on climate change and marine mammals that Ari Friedlaender and I are teaching this spring at the lab. We now have a tool that allows us to compare current conditions in marine mammal habitats (surface air temperatures at pinniped haul outs, ice conditions in both polar regions, sea surface temperatures etc…) around the world with what may occur if global warming occurs according to a range of predictions, and that provides for a lot of material for projects in the class!
[image title="SST after 100yrs - EDGCM IPCC A1" size="large" align="center" icon="zoom" lightbox="true" autoHeight="true"]http://superpod.ml.duke.edu/johnston/files/2010/12/IPCC_A1_GISSII_WINTER_2100.png[/image]
