Wrapping Up

This is the final blog posting for this expedition. We were back out in the canyon this morning with a whale that let us get some more good FLIR images. But with a forecast for 30 knots out of the south we decided not to deploy a Dtag because, if we had to leave the area without retrieving it, we would not be very welcome back in Woods Hole.

Male orca (Will Rayment, University of Otago)

On the way in we were treated to a busy group of Orcas all around the ship and some dusky dolphins foraging on a bait ball. Of course, the forecast turned out to be utterly wrong, but if we had got a tag on a whale, no doubt it would have turned ugly. This evening we shared photos and video with the crew, and tomorrow we will be on to the next chapter.

Cruise track and whale sightings.
(Will Rayment, University of Otago)

Here is the cruise by the numbers:
·  We had a total of 75 photo-ID encounters. The map shows our sightings and track line. Each day is a different color. High quality fluke photos were obtained on 51 occasions, representing 15 individuals. We encountered each animal between one and eight times.
·  The listening vessel ran a total of 367 nautical miles.
·  We also acquired a total of 35 hours of Dtag data from 7 tags. The deepest dive we recorded was 1,439 meters.
·  We acquired nine skin samples, FLIR data from three animals, and aerial camera images of two.

Thus, we did well with the photo-IDs, skin samples and Dtags, while the more developmental aspects of the project—aerial camera imagery and breath sampling—we brought a long way down the road. In summary, we all worked very hard, had a grand time, and have added to the knowledge base of how sperm whales use the Kaikoura Canyon.

We also saw some amazing wildlife: sperm whales, dusky and Hector's dolphins, albatross, petrels, shearwaters and much more.

This blog would not be complete without a huge thank you to the owner and crew of the Alucia for their support and patience throughout the cruise, and to many colleagues at Woods Hole Oceanographic Institution. We would also like to sincerely thank the whale watch community of Kaikoura for their advice and support in planning and undertaking this cruise. There are also a significant number of folks in various parts of the New Zealand Government that have made permitting of our work possible. As Chief Scientist on the cruise I would also like to thank Andreas, Don, Julie, Leigh, Liz, Luis, Marta, Maryann, Micah, Moe, Wayne and Will for their endless hard work and goodwill

Michael Moore

FLIR

There’s a member of our team that's a bit shy. She’s stayed on board when the seas have been choppy, and she’s rarely seen outside of her pelican case. Her name is FLIR. She hates to get wet. In fact she can't get wet. Otherwise, her parents get very upset.

FLIR is an infrared camera that we have set up to record infrared video. Using FLIR, we can see a sperm whale’s blow more clearly than with the naked eye, which is affected by wind, humidity, and air temperature.

Julie van der Hoop using FLIR. (Maryann Keith,
Advanced Imaging & Visualization Lab, WHOI

The idea is to use FLIR’s video to determine how fast a whale exhales. From there, we can figure out the amount gas that the whale has exhaled. This volume of inhaled and exhaled air, also known as the tidal volume, is a very important parameter for estimating metabolism, and is currently unknown for free-ranging large whales.

Tidal volume is only a fraction of lung capacity. An adult human male has a lung capacity of around six liters, but tidal volume is on the order of 500 milliliters. This means that, although we have the ability to exchange a lot of respiratory gases (oxygen and carbon dioxide) in a single breath, we typically move much less. Knowing how much oxygen and carbon dioxide is exchanged with every breath is a missing parameter when it comes to understanding marine mammal diving physiology.

The breathalyzer system that our research team has developed is another way to measure tidal volume by directly measuring the exhaled flow. Although the breathalyzer requires very animals to cooperate with our hand-pole approach, we can use FLIR from a distance and can calibrate it yield similar results. It’s our hope that one of these approaches will help us better understand the physiology that allows these animals to dive to such great depths for extended periods, time after time.

We are very grateful to our colleagues Ann Pabst and William McLellan at University North Carolina Wilmington for the loan of FLIR.

FLIR image of a cooperative sperm whale. (Maryann Keith,
Advanced Imaging & Visualization Lab, WHOI

On March 5 FLIR took center stage when an obliging sperm whale surfaced close to the Zodiac. We were able to shut down the outboard and sit and watch in awe as this monstrous male sperm whale slowly passed us by just a few feet away, while Julie acquired a series of infrared images of the blow using FLIR. The whale must have seen the boat but it never flinched, it just slowly pushed along the surface, blowing hard to restore its oxygen debt before fluking up to head down back to the bottom of the canyon for another hour of foraging.

A look back

We poked our nose out beyond the Kaikoura Peninsula but it was far too windy to do fieldwork today. Plenty of paperwork needed to be done though, mainly processing the data from the last few days of fieldwork.

We saw lots of whales on Saturday. Will Rayment and Liz Slooten were tracking whales and doing photo-ID. The WHOI team tagged two whales and flew the hexacopter above the whales to get measurements of their body condition. We retrieved our last tag was after midnight. A really productive day!

HL.160 "Tutu" showing his fluke.
(Will Rayment, University of Otago)

We are already starting to analyze the data, and over the next few months will be very interested to find out how data from this field trip compare to the long-term Kaikoura dataset. In 1990, Liz Slooten and Steve Dawson from the University of Otago started a research project on sperm whales in Kaikoura, using photo-ID, sound recordings, and behavioral observations. Graduate students and post-docs who joined the project include Nathalie Jaquet, who studied seasonal changes in the distribution and behavior of the whales. Caron Chessum, Simon Childerhouse, and Miranda van der Linde determined that the number of whales in the Kaikoura area has declined significantly from almost 100 individuals in 1991 to about 50 individuals now. (We are not yet sure if this means a shift in their distribution, with fewer whales coming close to shore, or an actual decline in the population.) Christoph Richter carried out detailed studies on the effects of tourism on sperm whales. Olaf Jaeke and Lesley Douglas studied sperm whale sounds, and Abe Growcott and Quin Rhinelander used the whales’ sounds to estimate their size. Brian Miller used a hydrophone array to follow the whales underwater. The University of Otago team also built directional hydrophones and hydrophone arrays for finding whales, and a stereo-camera system to measure whales.

Dusky dolphin at play. (Will Rayment, University of Otago)

Background data from the long-term study provide the context for the joint WHOI–University of Otago project. For example, one of the whales we tagged on this trip, known as Tutu or HL.160, was first seen in 1991 and has been seen 127 times since then. This is clearly a mature male. Another whale seen on this field trip, LNL.160, has been seen 180 times since 1994. Repeated estimates of this whale, using the stereo-photography and acoustic length measurements show that it has grown from 14.6 meters to 15.1 meters. These data on age and growth will be very useful in interpreting the information gathered on this field trip.

Hector's dolphins. (Leigh Hickmott, Open Ocean
Consulting/University of St. Andrews)

If the data on diving behavior we get from the DTAGS turn out to be similar to the data from the hydrophone arrays, then information from the two methods can be combined to provide insight into the diving behavior of sperm whales. On the other hand, if the results are different this will lead to further questions about whether the differences are due to the different techniques, differences between the individual whales in the two data sets, differences in the locations, changes in oceanographic conditions this year compared to earlier years, or a combination of the above.

To provide a break from the database work today, we did some research on two of the sperm whales’ smaller cousins. We spotted some Hector’s dolphins and dusky dolphins in the calm water on the north side of the peninsula. The dusky dolphins were doing their usual leaping and bounding. The Hector’s dolphins were much less boisterous, but very approachable and curious. Two of the Hector’s dolphins had joined a group of dusky dolphins, which is unusual. We took photographs that will be added to long-term photo-ID catalogs for these two species.

You are what you eat

Beneath the beauty of the animal kingdom there is a fierce world, in which you are either hunting or you are dinner. Life is a constant struggle for survival, and finding food is essential to existence. That is why one of the most important questions in the study of wild animals is: "What do they eat?."

A wandering albatross wandering in search of a meal.
(Will Rayment, University of Otago)

In the ocean, the quest for food often requires going far or deep. Some animals travel hundreds of miles over the ocean just to find a meal. Such is the case of the wandering albatross, a magnificent seabird that we often see off the coast of Kaikoura. Satellite tracking of wandering albatross has revealed that they can cover up to 15,000 km from their nest on a single foraging trip, flying day and night at speeds of up to 80 km per hour (50 mph).

Almost everything about sperm whales is superlative: they are the largest of the odontocetes (toothed whale), the deepest diving cetacean, and their echolocation clicks are the loudest underwater sound produced by any animal. Their biology and physiology are fine products of thousands of years of evolution which allow them to go as deep as 2,500 meters (1.5 miles) and as long as two hours to locate their prey.

To date, there has been just one analysis of the diet of sperm whales in New Zealand. The study revealed that sperm whales eat squid and a relatively high proportion of bottom-living fish. This is intriguingly distinct from sperm whale populations elsewhere, which eat almost exclusively squid. Understanding the diet of these animals allows scientists to identify their role in the ecosystem and provides a better understanding of their distribution and habitat use. In turn, this information is very valuable for conservation management.

But how do we find out what these animals eat if they spend most of their time at great depths underwater and don’t feed at the surface? The answer can be provided by the analysis of stable isotope signatures from whale skin. Studying stable isotopes is a non-invasive method that can provide information on diet as well as physiology and ecotoxicology.

Collecting sperm whale skin from a DTAG.
(Wayne Perryman, SWFSC, NOAA)

Isotopes are variants of a particular chemical element, and stable isotopes are those variants that remain stable over time. The stable isotope composition (say, for carbon and nitrogen) in an animal is largely determined by the isotopic composition of the food, water, and gas that the animal takes in. These elements are eventually used for making new soft tissue (like skin) and biological minerals. Through the analysis of the composition of stable isotopes, researchers can track down the primary source of the animals’ diet by matching those isotope signatures of the skin to the ones of potential prey species.

Getting our hands on samples of whale skin is a tale of persistence and patience. Every time a sperm whale dives, there’s a chance that small strips of sloughed skin will remain at the surface. We only have to keep our eyes open for those skin fragments in the slick left by a fluking whale, have a net at hand, scoop it up, and put it in the freezer. We also often find small pieces of skin trapped in the suction cups of DTAGs. Later on, stable isotope analysis can be carried out back at the laboratory.

During the expedition we have so far collected nine skin samples. They are happily frozen and waiting to be analysed—ahopefully to reveal a little more about the diet of sperm whales and what makes Kaikoura such a productive foraging ground.  

Further reading on stable isotope analysis: 
Newsome, S.D, Clementz, M.T., and Koch, P.L., "Using stable isotope biogeochemistry to study marine mammal ecology," Marine Mammal Science 26 (2010): 509-572.

Whales, whales and more whales

Today dawned grey and cold.

Liz Slooten (crouching) listens for whales. (Maryann Morin,
Advanced Imaging and Visualization Lab, WHOI)

We started looking for whales to the southwest of where we have been working recently. We were interested in a tongue of the canyon that looped northeast, with a nice loop around the 1,000-meter contour, but there was nothing to be seen or heard, so we headed back offshore and went northeast to an area where we had been finding whales earlier in the cruise. Before we knew it we were spoiled for choice.

Tag on! (Will Rayment, University of Otago)

Andreas and Micah piled into the kayak, along with their gas sampling gear and breathalyser funnel system, and off they paddled. A pair of sperm whales sensed them coming, turned and proceeded to do a number of spyhops. It seemed as this if they were curious about this hitherto unseen contraption that had arrived in their patch of ocean. Indeed, the kayak and the spyhopping whales came very close to each other, but unfortunately a spyhop does not include a breath, so their breath remained unsampled. However, Julie van der Hoop was finally able to get some infrared imagery of sperm whale blows, something we have been waiting to do until the conditions were calm enough to avoid any water on the camera.

We then managed to get a couple of tags deployed later in the afternoon over the space of half an hour. Meanwhile, Archie the aerial camera was feeling confident after yesterday's trials ashore, so Don and Wayne did some trials around the ship. When an opportunity arose, Archie sallied forth over a tagged
whale and acquired good aerial images before returning
safely home. To be able to do this in a rolling swell is a
huge accomplishment. Don and Wayne have worked
through the many challenges they have faced and come
up smiling.

Archie's view of a tagged whale.
(Don Leroi, Aerial Imaging Solutions and
Wayne Perryman, SWFSC, NOAA)

It is wonderful to have Liz Slooten from the University of Otago and the New Zealand Whale and Dolphin Trust aboard now, with her extensive knowledge of these animals, the area, and acoustic tracking. We miss Luis lamar, but in his stead we have Maryann Morin, also from the Advanced Imaging and Visualization Lab at WHOI. So welcome aboard to Liz and Maryann.

Waiting for weather and Archie reincarnated

We woke to a stiff southerly breeze this morning. New parts for Archie, the aerial camera, have been installed, so Don and Wayne went ashore to look for a sheltered spot for his first flight after his dunking. We then headed offshore and heard and saw a whale, but the swells were steep and lively, so we retreated. Archie went ashore for more exercise. The forecast for tomorrow is good.

We were sad to say goodbye today to Luis Lamar, photographer extraordinaire, and Marta Guerra, whale tracker, tag-in-the-water spotter, and all-round great colleague.

Aerial Camera Update 

Bubby and Bubby. (Moira Brown, New England Aquarium)

Changes in the reproductive and nutritive condition of large cetaceans are reflected in changes to their shape. These changes can be very accurately measured from overhead aerial photographs, which provide insight into how both long- and short-term changes in the environment and other, human-related factors impact populations.

This field of research began with photographic missions conducted from manned platforms (airplanes, helicopters) but new developments in imaging systems and unmanned aerial technologies are providing an opportunity to take this kind of sampling into situations where it wasn’t available previously or was prohibitively expensive.

Bubby takes flight. (Moira Brown, New England Aquarium)

We have had success using measurements from vertical images to track changes in the condition of North Atlantic right whales and eastern North Pacific gray whales. What we are learning is that the location in which a whale stores nutritive capital (mainly fat) varies among species. Moreover, to efficiently monitor changes in condition over time, we first need to look carefully at the shape of several individuals within a population to identify the parts of the body that appear to show the most variability in the relationship between length and width of the animals. Our study is the first step in that process.

Don and Wayne adjust the gyros on Bubby's stabilized
platform. (Moira Brown, New England Aquarium)

While waiting for a part to repair Archie after his unscheduled flotation test last week, the team completed construction of a small quadrocopter that has a water-tight hull and seems like an ideal solution to the challenge of working from the small boat to approach the sperm whales. The new aircraft, named Bubby after a young member of the deck crew, flew beautifully and we found that we could time the motion of the small boat to the point that we could calibrate Bubby’s gyros under calm conditions.

Launching Bubby from the boat was relatively simple and safe, but catching him on his return to a very lively platform turned out to be a harrowing experience. The primary problem we faced was that the momentum of the boat’s movements were transferred through the pilot’s fingers to the sticks of the flight controller, making it very difficult to safely maneuver the aircraft into the hands of the "catcher." For that person, it was like trying to handle a wild pitch from a knuckleballer. The next iteration of Bubby will be designed to splash down beside the small boat so that we can simply retrieve him with a net.

In the meantime, we have Archie, our hexacopter, back up and running. So our plan now is to go back to our original approach of maneuvering a bit closer to the whales and launching Archie from the ship's helicopter deck. Now we just need a break in the weather to get back to work.

Why Kaikoura?

Today there were monster swells in the ocean above the Kaikoura Canyon, and when the wind started to blow hard, we spent the day at anchor southwest of Kaikoura Peninsula taking stock, looking at data, and generally gathering our wits about us.

So, why have we decided to do this work off the Kaikoura coast and not someplace more convenient to Woods Hole? There are very few places in the world where sperm whales can be reliably found close to shore. Kaikoura is one of them. The feature that makes the location so special is the Kaikoura Canyon—an undersea trench that cuts through the continental shelf such that the seabed plunges to depths over 1000 metres within 4 kilometres of the coastline.

A sperm whale heads for the deep waters of the Kaikoura
Canyon to feed. (Will Rayment, University of Otago)

Whales aren't the only marine mammal attracted to the food
supplied by the riches of the canyon. Here, a New Zealand
fur seal. (Will Rayment, University of Otago)

The biological productivity within the canyon is enormous. Scientists have recently revealed that the biomass of seabed-dwelling invertebrates in the Kaikoura Canyon is 100 times greater than in typical deep-sea habitats. Likewise, the densities of bottom-living fish are dramatically higher in the canyon than on the surrounding seafloor.

This presumably makes the Kaikoura canyon a great place to look for food. And sperm whales need a lot of food. They are the largest of the odontocetes, the toothed whales, and probably require up to 1.5 tons of food per day. As we have seen from our DTAG data, they routinely dive to over 1,000 meters looking for their prey, primarily squid and bottom-living fish. Exactly what they eat at Kaikoura remains to be seen and is something we hope to learn from our analyses of their sloughed skin and fecal samples.

But it’s not just sperm whales that make use of the abundant food supply at Kaikoura—a there is a plethora of other marine mammal species that exploit this rich submarine larder, as well. Kaikoura is home to large numbers of dusky dolphins, which can be seen playing and resting in the coastal waters during the daytime before heading offshore to feed at night. Similarly, New Zealand fur seals rest up and bask on the rocky coastline, then swim out over the deep canyon waters to forage. There are a number of more transient visitors, too. So far, during our brief visit we have seen southern right, blue, and killer whales. And the productive waters are a Mecca for seabirds. Every day we are surrounded by albatrosses, petrels, and shearwaters, all looking for a piece of the action.

Seabirds like this Buller's albatross are attracted by the
productivity of the canyon--and the antics of scientists.
(Will Rayment, University of Otago)

The abundance and diversity of marine life makes Kaikoura a great place for scientists to work. Similarly, it’s a big draw for human visitors, and there is now a thriving tourism industry in Kaikoura. People come from far and wide to go whale watching, swim with dolphins, and view the huge variety of seabird species. During our time here we have come to realize just how lucky we are to do what we do in such a special environment.

Further reading:
De Leo et al., "Submarine canyons: Hotspots of benthic biomass and productivity in the deep sea," Proceedings of the Royal Society B 277(2010): 2783-2792.

Errands and celebrations

Julie fixing a Dtag in the lab. (Luis Lamar, Advanced
Imaging & Visualization Lab, WHOI)

Today we had a number of errands to take care of on shore. First, two of us went up in a local helicopter to listen in vain for a missing tag. The hexacopter crew also went ashore for more trials with Bubby, and to track down parts for Archie, Bubby's elder brother.

Bubby flew really well (proudly watched over by his namesake, the Alucia deckhand), so they then tried to launch from the ship's tender. That also went well, except that catching a hexacopter by hand in any kind of swell is difficult. They've concluded he needs to be fully amphibious to allow a water landing near the boat .

After our errands were finished, we headed offshore to deploy the breathalyzer, as there was less swell than yesterday.

But the whales had different ideas, zoo we called it a day at a remarkably early 5:30 p.m. and headed to the ship to celebrate . . .

My Birthday on a Boat 
by Julie van der Hoop (WHOI/ MIT Joint Program PhD student)

Julie celebrating with friends. (Moira Brown,
New England Aquarium)

Today is my 25th birthday, and how better to spend it than at sea, surrounded by marine mammals, enjoying beautiful weather, and celebrating with new friends.

After a late night spent with DTAG data I decided to sleep in until 7:00 a.m.--a luxury for sure. But what was even more luxurious is the fact that I had a chance to squeeze in a workout while Bubby was on a test flight in calm winds in Kaikoura Harbour. Nothing beats the view from the elliptical on the Alucia.

Julie's card. (Jerry Conway, Canadian Whale Institute)

With calm waters in the harbor, we headed out in a Zodiac to photo-ID some inshore whales. Will, Marta, Leigh, and I were lucky enough to come across two whales, one that we had previously tagged. We were also keeping an eye out for skin samples to collect for stable isotope analysis to determine the diet of sperm whales in these waters.

Scanning the water, we saw no skin but skimmed up some mystery substance to try to figure out just what it was. As it turned out, on my birthday, I sat on the side of the Zodiac, holding whale poop (specifically partially digested squid mantle, we think) in my hands. Few people can say that.


I spent a fantastic afternoon on the fly bridge spotting blows, directing the small boats, watching the "breathalyzer" in action, and enjoying the austral summer weather.

Marta Guerra holds a sample of semi-digested
squid found in the feces of a sperm whale.
(Julie van der Hoop, WHOI)

At dinnertime, I was presented with a delicious (and vegan!) cake along with a card signed by the science team and ship’s crew. A Canadian colleague who wasn’t able to join us on the trip had done a fantastic drawing and had sent it by email. Everyone on board has made me feel extra special today, and has gone out of their way to spread the birthday love!

And as for a gift? Today, I came so close to fulfilling one of my life goals. Leigh spotted a blue whale, but try as he might, wasn’t able to spot its next surfacing. Though I’ve seen new species this trip (southern right whales, dusky dolphins, New Zealand fur seals), I can’t count a blue whale that I didn’t see.

Maybe on my 26th birthday.

The whale brethalyzer

Today we went up the hill again to listen for the missing tag in vain. Bubby, the aerial camera, got a work out from the ship's tender (he needs more work) and the breathalyzer got an inshore trial. Then went offshore about 12 miles southeast of the Kaikoura Peninsula and found a whale in some large swells, but decided that the breathalyzer needed a calmer day for its first deployment. We were able to attach a tag, however.

Diving marine mammals live a life of dual constraints. One the one hand, they want to maximize their time underwater to increase foraging success and the number of prey captured. On the other hand, they need to return to the surface to replenish their oxygen stores, which they use to generate energy while underwater.

In a changing environment, where prey density may have been reduced either by overfishing or increasing temperature of surface waters, marine mammals may have to dive longer to catch enough food to survive. Consequently, oxygen management becomes the limiting factor in the time they can spend underwater and, consequently, the amount of food they can capture during each dive. For this reason, physiologists are interested in measuring the metabolic rate, or the rate of oxygen consumption, in marine mammals.

In smaller, captive species, physiologists can measure expired oxygen fairly easily and, from this, estimate the metabolic cost of longer dives. Measuring the oxygen consumption in large whales, on the other hand, has been a bit more difficult. To do this it is necessary to measure to volume of air exhaled in a unit of time and to determine the composition of the expired gas.

To measure the amount and composition of air a sperm whale exhales, we have to place a flow meter and gas analyzer directly over the animal's blowhole when it exhales. To do that, we have to come within a few meters of a while while it is at the surface—not an easy task when you are dealing with an animal that may weigh up to 40 tons that swims at one or two knots in an open ocean with varying swell.

Mike Morrissey, New Zealand Department of Conservation
wearing a helmet camera. (Luis Lamar, Advanced Imaging &
Visualization Lab, WHOI)

We have had the opportunity to learn how to approach these giants in kayaks from our colleague Mike Morrissey at the Department of Conservation. This approach first involved transporting a kayak close to a whale by small boat. After launching the kayak, we approached the whale from the side until we were within one or two meters, at which point we were going to extend a pole to measure and sample the exhaled air.

On the second day of the cruise, we practiced approaching a whale and came within four or five meters before the animal increased its speed and finally decided to dive. During the days that followed, we came closer but realized that managing electronic equipment and a six-meter carbon fiber pole while at the same time paddling next to a whale would minimize our chances of placing the flow meter over the blowhole successfully. Instead, we will attempt close encounters with the whales using one of the small boats. For this purpose, we have rigged one so that we can extend our reach with the precision we need to capture the exhaled gases. We are now waiting for calmer sea conditions so we can test our idea and possibly be the first who captures the exhaled gases of a sperm whale.

Micah Brodsky with the Mark 2 Whale Brethalyzer
(Luis Lamar, Advanced Imaging & Visualization Lab, WHOI)

To measure the volume of expired air we are using a custom-made flow meter, which we have named the whale breathalyzer. BRETHALYZER The breathalyzer is secured to the end of a carbon fiber pole and connected to a pressure transducer that measures gas flow. It also includes an oxygen and carbon dioxide analyzer, which measures the gas composition of the expired air.

The captured air will allow us to estimate the amount of oxygen consumed during the whale's previous dive and get a better picture of the work it to capture its prey. Once we have captured expired air from several whales, we can examine work effort using the DTAG data and create a better picture of how much energy it takes to capture a giant squid.

After fabricating several prototypes from a variety of materials, this second-generation prototype was designed and built out of carbon fiber. The experience, hard work and dedication of the folks mentioned below made it possible to take an idea and transform it into a completed prototype in a record five days.

Dr. Brodsky and Dr. Fahlman would like to thank Trevor and Penny Austin at PaxArms; and Andy, Davie, and Jenny from Davie Norris Boatbuilders.

The routine

We have been on this cruise for a week now. Maybe it is time for a bit of a recap to describe how our routine has been shaking out, and what we all get up to all day.

By dawn the ship heads to a spot in the mouth of the canyon where we hope to find whales. The sun gets up around 6:30, which also reveals bleary-eyed scientists in the mess fixing their favorite blend of cereal, yogurt, fruit, etc, given that the heartier fare isn't set out for a while yet. Whether they got much, if any, sleep the night before depends on if we were tracking a tagged whale or looking for a released tag overnight.

Another day, another tag. (Luis Lamar,
Advanced Imaging & Visualization Lab, WHOI)

Regardless, our trusty scouts, usually Will, Marta or Moe, and Andreas then head off in the ship's tender with one of the ship's crew to listen and look for whales, while we also set a visual watch on the top deck. We take turns at this. Often by 9:00 or 9:30 they have started tracking a whale or two, so it's time for the Zodiac crew to mobilize: Leigh and Julie the taggers, Luis the camera guy, and Michael the driver.

We suit up and head off to join the tender, shut down the engine while Will and Marta determine where the whales are headed. We follow suit, heading in the apparent direction of the clicking and stopping to listen every while. When a whale goes silent ,we start to look out over the water in earnest.

Often, the first to see the whale blow is the person on the top deck of the ship. The Zodiac crew then moves over into a spot behind the whale, slows down, sets a tag on the end of the pole, checks that the ship can hear the radio transmitter, and then ever so gently creeps up behind the whale. Finally, if the whale lets us, we can gently place the tag on its back. If it does not want us there it quickly becomes obvious and we move on to another whale and start all over again.

Once the tag is on, the Zodiac crew returns to the ship and we start radio tracking the whale. A whale will usually surface every hour, at which time we can hear the beeping associated with a surfaced whale, and thus stay with it.

Meanwhile, the ship's tender heads off to look and listen for other whales to get photo-ID images and a better sense of where in the canyon the whales can be found. Once the tag attachment time has elapsed—usually 3 to 6 hours—the tag detaches and slowly surfaces, at which point we detect a continuous beeping that helps us direct the ship so that we can scoop the tag with a dipnet and start downloading the data.

A white-capped albatross taking flight (Luis Lamar,
Advanced Imaging & Visualization Lab, WHOI)

Meanwhile back in the lab, Wayne and Don are busy with their aerial camera system. Archie is still waiting for parts to be delivered, while his buddy, who today was christened Bubby after one of the ship's deckhands, is almost ready for prime time. The plan is to test fly Bubby off the ship's tender tomorrow. Andreas and Micah are also busy with version two of their breath-sampling device. That, too, may see prime time tomorrow if inshore trials go well.

Today we were surrounded by many Buller's Mollymawk, a local albatross.

The DTAG

This afternoon, we finally found an animal that was approachable and attached a tag programmed to release in 6 hours, so we hope to retrieve it before midnight tonight. While we wait, watch, and listen for the signal that it is on the surface, here is some background about the tags.

Our oceans are not only vast, but also deep. Some marine mammals have evolved the means to exploit resources and ecological niches far beneath the surface.

This is no mean feat, as the deep ocean is an inhospitable place, with cold temperatures and extreme pressures. As an object descends in the water column, the pressure it experiences increases by one atmosphere with every 10 meters. Thus, an animal that dives to 1,000 meters experiences 100 times more pressure than when it as at the surface.

To study deep diving odontocetes—toothed whales such as sperm whales, beaked whales and pilot whales—that forage at depths in excess of 1,000 meters (where no scientist can easily follow), novel techniques are needed to document their behaviour. One such method is to attach data logging devices capable of surviving the rigours of deep ocean exploration. Engineers at WHOI developed just such a device, known as a DTAG, that is able to digitally record movement and acoustic data (Johnson & Tyack 2003).

Three-dimensional dive profile

The DTAG is a non-invasive, cell-phone-sized tool that contains a suite of sensors that includes either a single or a pair of hydrophones (underwater microphones), three magnetometers, three accelerometers, and instruments that record temperature and pressure. These sensors are able to record data 50 times per second, the result being incredibly fine-scale, high-resolution data that can shed a detailed light on a tagged animal’s three-dimensional movements while carrying the tag. The hydrophone in the DTAG is able to sample at a rate of up to 192 kHz and records all the sounds the tagged animal makes and the sounds that it hears while moving through its environment.

Attaching a DTAG. (Luis Lamar, Advanced
Imaging & Visualization Lab, WHOI)

In order to attach the DTAG to a whale, it is placed in a fairing that contains floatation foam, a VHF transmitter, and four soft suction cups and attached to the end of an eight meter carbon fiber pole. A team approaches slowly and quietly in a small boat to minimize disturbance to the whale at the surface. As the body of the animal rises up out of the water the team member on the bow of the boat attaches the tag to the dorsal surface of the animal. The tag is attached to the dorsal surface of animals. After a pre-programmed length of time, the suction cups release automatically.

The capabilities of the DTAG have enabled scientists to shed new light on the diving, fine-scale foraging, and acoustic behaviour of many marine mammal species. It is now helping us to investigate the behaviour of the large male sperm whales of Kaikoura.

1,400 meter dive

The sperm whales here in the Kaikoura Canyon begin making echolocation clicks soon after they "fluke up" to start a foraging dive. As they descend into the depths they produce loud clicks. By interpreting the echoes that return, the sperm whales are able to navigate beneath the surface and detect prey in the darkness beyond the reach of sunlight. So far, our tagged whales have dived to depths of almost 1,400 meters to feed.

The echolocation clicks that the whales produce have a rhythmic nature to them and can be heard for many miles. When potential prey, such as squid, are detected the sperm whales home in on their quarry and then switch from the regular echolocation clicks to a rapid sequence of clicks known as a "buzz" as they attempt to catch their prey. After foraging for almost an hour, the sperm whales return to the surface to breath before heading back to the larder of the abyss once more.

Frequency spectrogram of a
click-buzz sequence.

By attaching the DTAG and analyzing the natural sounds made by the whales, scientists are able to provide previously unavailable perspectives on the three-dimensional nature of their foraging behaviour. Such data can be used to fill information gaps about diving behaviour that can, in turn, be linked to foraging. In particular, how whales exploit the water column during foraging events and how animals respond to the ever-increasing presence of human-produced noise in the oceans. 

Reference
Johnson, M. and Tyack, P. L., "A digital acoustic recording tag for measuring the response of wild marine mammals to sound," IEEE J. Oceanic Eng, 28 (2003), 3-12.

How to radio track a tag

It seems the whales have wised up today.

We worked with a couple this morning and another this afternoon and each one was less cooperative than in previous days. But they were smaller animals and so perhaps less tolerant of our presence. Plus, we are using a tag with an extra piece to it, which makes it less easy to deploy. So we struck out today in terms of tagging.

We did, however, get good photo-ID images of three animals and a skin sample—a total of five so far, which is beginning to look like a sample set worth looking at for the planned dietary studies.

Julie van der Hoop listens for a tag.
(Luis Lamar, Advanced Imaging & Visualization Lab, WHOI)

Perhaps this is a good time to tell a bit more about how we recover the tags. Because they are slightly buoyant, the tags slowly rise to the surface after releasing from a whale. Once at the surface, their radio transmitter broadcasts a steady beeping, which we can hear using directional antennas (hand-held and installed on the ship) and a suitably tuned radio. With these, we can acquire a bearing on the tag and move in that direction. As we approach the tag, the signal gets stronger and stronger.

The signal of a tag floating at the surface is very different to one from a tagged whale. While on a whale, we detect a periodic chirp or two as the animal it is on surfaces every 45 to 60 minutes, especially as the whale arches to dive; once on the surface, the tag beeps continuously. Once we get a visual sighting of a tag in the water, which is by no means easy, we then maneuver nearby so we can retrieve it using a dipnet.

Leigh Hickmott detects the missing tag.
(Marta Guerra, University of Otago)

The other day, we had to leave a recalcitrant tag on a whale (one that we'd been trying to recover for two and a half days) and head for shelter. Once on shore, we climbed the nearest hill to get a better vantage point to listen for the tag. There was jubilation when we finally detected it, and we carefully took a bearing so the ship could run down the bearing to relocate it. Once back on board the sense of relief was palpable. It had been stuck on the whale for 36 hours or more and it had been causing more than a little loss of sleep.

Leigh Hickmott retrieves the errant tag from the bow of the ship.
(Luis Lamar, AIVL, WHOI)

So that might give you a bit more of a sense of the various skills our team has: radio tracking, tag application, photography, boat driving, microelectronics, data analysis—and a boat load of patience.

Tonight our aerial imaging team will test fly their new bird on shore so that it can get a sense of which way is up before it gets to fly off the ship tomorrow. Hopefully. Some of you older comic readers might have a sense of what it has been christened.

Figuring out who’s who in the Kaikoura Canyon

Today played out at a slower pace than yesterday. The stuck tag remained elusive and the weather precluded any thought of small boat activity, so we retreated to the town of Kaikoura for the night.

Our tracking crew climbed a hill and were able to get a bearing on the missing tag had finally released from its whale. So we all went back out in the Alucia, homing in on the tag's signal, and were able to recover it. The malfunction had been caused by seawater entry into the tag. It is now winging its way to Woods Hole in the hope that it has retrievable data.

Today was a relatively quiet day, so we thought we'd give you some background on why it is so useful to photograph marine mammals so carefully and systematically.


Figuring out Who’s Who in the Kaikoura Canyon: How sperm whales tell us their stories

A sperm whale surfaces after a long dive

The ability to identify an individual whale from photographs, or photo IDs, of the animal taken during short encounters at sea allows scientists and naturalists to assemble the pieces of a very large life-history puzzle one image at a time. Coordinated efforts have produced photographic catalogues for many marine mammal species including sperm, right, blue, and humpback whales, to name a few.

From the information in the ID catalogues, researchers can piece together an animal’s migrations and pattern of habitat use on scales from one day to a period of years. We can also use photo-ID data to estimate how many animals are in a given population, how long they live, how often they have calves, and who they prefer to hang out with.

February 19, 11:16 a.m -

Our photo-ID work here in the Kaikoura Canyon is focused on sperm whales. We are contributing to the sperm whale catalogue compiled by the Marine Mammal Research Group at University of Otago. As more and more photographed sightings of each catalogued individual are collected during a day, from day to day and even over months and years across many locations, the story of the lives of individual whales is developed into an epic tale--or, in the case of the sperm whale, an epic tail.

Photographing sperm whales is the epitome of hurry-up-and-wait. The researchers on the photo-ID boat track a whale’s movement underwater with a directional hydrophone for 30 minutes to an hour; the goal is to be within a few hundred meters of the whale when it announces its presence at the surface with a robust exhalation.

February 19, 12:18 p.m.

The vessel eases over to the now surface-resting whale, staying about 75 meters astern to be ready when the animal hoists its flukes and reveals the unique markings along the trailing edge of its tail. Photographers are positioned on the bow of the boat, at the ready with hefty cameras held at eye level (the favorite is a Nikon D3 with a 300mm lens). Now it is just a matter of firing off a series of shots as the whale lifts its flukes skyward to sound for another feeding dive. Squid and fish of the Kaikoura Canyon beware!

On the right are images of a whale we’ve already seen multiple times on this trip. The nicks and notches on the fluke make it very distinctive. With each photographed sighting, we collect time, position (in latitude and longitude), as well as dive and surface intervals. At the end of Day 2 we had three sightings of the same whale, which gives us and idea of its movements and an its preferred habitat. Two days later we identified it again, still hanging out in the same area.

February 19, 3:01 p.m.

The fun part begins once we are back at our computers, where we can compare the images from the day to the ones in the sperm whale catalogue to search for a match. This time, we checked our email first and it turns out that the image of the sperm whale dorsal fin posted in our second blog entry has already been recognized by the experienced eyes at Whale Watch Kaikoura as a whale known as Tutu. Sure enough, Tutu is also in the University of Otago sperm whale catalogue, but with the slightly less prosaic name of HL160. Looking back through our records tells us that HL160 has been seen at Kaikoura regularly since 1991—a true local!

February 21, 9:13 a.m.

The more photos, the merrier the knowledge. The sperm whales of New Zealand have let us learn a lot about their personal histories, and the longer the photo-ID project goes on, the more powerful that resource become.

All images on this page by Will Rayment, University of Otago.

A bad day fishing is better than a good day at work

But what happens when you are working, and fishing for data, and you have a really bad day. You talk to your team and look for the good news. That sums up today pretty well.

Dtag being attached. Ideally it releases later. (Luis Lamar,
Advanced Imaging & Visualization Lab, WHOI)

Wednesday night we attached a Dtag to a sperm whale at 19:30 local. It was programmed to release at 22:30. We heard the VHF beep on the tracking system occasionally through the night, when it was supposed to be steadily beeping at the surface waiting for us to pick it up. We slowly realized that the tag was still diving with the whale and returning to the surface about every hour, but its location on the animal meant that it could not transmit well, as it was mostly submerged even when the animal surfaced to breathe.

The result was a long and utterly sleepless night. Nevertheless, this morning our indefatigable tracking crew was out listening and watching and managed to relocate the animal. Indeed, the tag was still on where we had left it. The release mechanism must have failed. These tags are expensive—and priceless to us while we're out here. We have to recover it. That is the status of the tagging effort.

Archie taking off on his first (and hopefully not last)
science mission. (Luis Lamar)

But there is still more bad news, though with some serious silver linings. Archie, the aerial camera system, had a tough time today, as well. It was a calm day, so we launched Archie and, for the first time, it flew from the ship to a position over a whale and took some photographs. On his way back, he got a bit lost in the haze, and pilot Don had to hit the "come home" button to tell Archie to return to the helideck. Trouble was that Archie was programmed to return to where the helideck was when he was launched. The ship had moved since then.

Archie did what he was told, but his target was gone and he went for a swim. Happily, he was right where he was supposed to be, patiently waiting to be picked up, albeit upside down in the water.

Sperm whale from the air (Don LeRoi, Aerial Imaging Solutions,
and Wayne Perryman, SWFSC, NMFS)

In talking with Don and Wayne about this they can see nothing but positives:
1) We measured a sperm whale from a radio-controlled device at sea for the first time.
2) Archie passed his first-ever swim test.
3) Archie needs a homing beacon.
4) In a long career, this was Don's first ever crash.

Archie is now disassembled and drying out in the lab in pieces, doubtless an older, saltier, and wiser bird. Don and Wayne are bizarrely happy—it is as if their protégé went out into the big, bad world and got beat up, but came back with data and a pile of lessons learned.

All the while, the crew of the good ship Alucia remain endlessly patient and supportive as we stumble our way through our research plan.

Archie joins the science crew

Sperm whale at the surface. (Luis Lamar, Advanced
Imaging and Visualization Lab, WHOI)

Today has been another full day here over the Kaikoura Canyon. Our routine of looking, and especially listening, for sperm whale continues. We are finding sufficient animals to do what we need to do and have attached two more Dtags. The first detached as programmed and is safe in the lab downloading its data files. The second is still traveling with its whale and will hopefully release later this evening for recovery before the weather turns.

Meanwhile, other aspects of the science plan are beginning to come into focus. Don LeRoi and Wayne Perryman, our aerial imaging crew, have been working hard to get ready for prime time. Getting an Aerial Remote Controlled System (we call it Archie) in a state of mind to be able to launch from a rolling, moving ship is not trivial. Lesser birds have failed to come home. Watching Don and Wayne work through the programming and calibrating of the gyro-controlled system has been as if a pair of anxious parents were readying a favored, but queasy child for school for the first time. This afternoon, Archie was finally ready--he took off and flew around the ship, took some video and came back again.

This may seem small beans, but for us it is a huge step forward. The next step is to fly Archie from the ship over a whale and photograph its body shape to get an index of body condition. We have used such data in the past from full-sized aircraft to make inferences about how body condition impact the growth, development and reproductive success of various whale species. We hope that Archie will become a regular tool in the toolbox for whale biologists.

Here is a quote (and a video) from Archie's proud parents about their charge's first test flights:

Today, February 20, the Aerial Remote Controlled Sampling (ARCS) system team struggled with the challenge of calibrating the aircraft’s gyros on a ship that was pitching and rolling in the seas left over from last night’s heavy swells and winds gusting over 20 kts. By afternoon, the winds had dropped, and after attempting to use a gyro-stabilized stand that we had constructed for this cruise we found that we could time the calibration to occur in a brief motionless moment in the ship’s roll pattern.

Once the calibration was completed, we made a short, low-level test flight to ascertain the platform’s stability. After this first flight, the bird was dubbed “Archie." We then performed three more successful flights near the vessel, each a little farther from home, until we were confident that the flight characteristics were not impacted by either the ships motion during calibration or the ship’s magnetic field when Archie was near the vessel.

Footnote: As this post went to press, Julie van der Hoop revealed that data from today's first tag recorded dives of up to 1,400 meters depth--about 4,600 feet, or almost one mile down.

Success in the Kaikoura Canyon

February 19, 2013

Will Rayment with hydrophone.
(Moira Brown, NEAQ)

There is nothing quite so sweet as success.

Today we set a watch on the top deck and started running a grid search pattern to survey the outer parts of the canyon for sperm whales.

In addition, we deployed our secret weapon out in the ship's tender in the form of Will Rayment from the University of Otago. His routine is to steam along, shut the engine down, and use a small, handheld hydrophone to listen for sperm whale clicks. Rotating the hydrophone allows him to determine of the direction from which the clicks are loudest, indicating the direction to head, to listen again.

As the boat gets closer to the whale, the sounds become louder and more "surrounding." At that point we wait and listen.

The whale will stop clicking before it surfaces--all eyes are peeled and as if by magic, there is the whale close by. Then we gently idle over in a Zodiac and apply the tag.

Leigh Hickmott ready to apply the Dtag.
(Marta Guerra, Univ. of Otago)

It sounds easy, and indeed this morning, that is just what we did. Leigh Hickmott, a veteran tagger from St. Andrews University plied his skill, and was able to attach a tag to the right side of the animal. It was not a very secure attachment, as not all four of the suction cups seemed to hold, but enough, the tag stayed on for its programmed three hours, came off and floated back to the surface, where we were able to retrieve it.

Tag secured (for the moment) and ready to record.
(Marta Guerra, Univ. of Otago)

There was a wonderful scene in the lab this evening as we all crowded around the laptop as Julie van der Hoop, A graduate student in the MIT/WHOI Joint Porgram, downloaded the data and made the first plots. So, for the first time we were able to get a sense of what these animals are doing at depth. It underwent 3 dives while it was tagged: two to 500 meters, and then the last dive before the tag detached went to 1000 meters, where the animal could be heard buzzing, which is a good sign of foraging activity. Getting new information about the dive behavior of these animals in this habitat is an important contribution to efforts to conserve this species.

Our work to better understand short and long term responses to stress are all coming along, albeit on a slower track than the Dtag work, but stay tuned for updates in that regard in coming days.

Dive trace of a sperm whale in the Kaikoura Canyon. (Julie van der Hoop, WHOI)