Packing up and heading home

Saturday was our last day on the water. Three pilot whale sightings and numerous attempts to deploy the ECG tag were unsuccessful - the whales were mostly uncooperative. Early in the day we tried to head north to the melon-headed whales, which the satellite tags indicated were in roughly the same area as when we tagged them on Friday, but the wind had picked up so we were forced south once more. So on Sunday we packed up. We're heading back to Massachusetts this afternoon, having collected some great acoustic recordings using the towfish and the Dtags that were deployed. The drifter buoy, which was only used once, on Friday, actually recorded some of the highest quality acoustics we collected.

Equipment to be sent back to WHOI

Fieldwork will continue in May 2013 - the last of four trips on this project. But next week Aran heads to Alaska to carry out hearing tests on beluga whales (Delphinapterus leucas) as part of ongoing health assessments. This project is in partnership with the Georgia Aquarium and the National Marine Mammal Lab. Check back here for regular updates on that project.

Got 'em!

Boy was it an eventful day.  Sharks. Marlin. Pilot whales. Spinner dolphins. Spotted dolphins. Rough toothed dolphins. And.... Peps.

(DTAG going on a melon-headed whale. WooHoo!  Photo: TAM, permit # 15530 to CRC)

We found melon-headed whales today. Also called, Peponocephala electra, or Peps, for short. And it was a great day with these animals which are a focal species for this project.  It was surprisingly calm winds and we were able to travel to the northwest side of the Big Island and the bank where these animals are often found. We steamed around for quite a few hrs, spotting all sorts of marine mammal species, as well as many schools of skipjack tuna and diving birds.  Finally, around 1 in the afternoon, we saw some gentile splashing on the surface. It was a group of about 250 melon-headed whales!  Pretty exiting. We spent the rest of the afternoon with the group. In the process we put out 2 Dtags (one for several hrs, one for several minutes), two satellite tags (which transmit the animal's location via satellite), lots of photo identifications, the towfish and a new device we call the Drifter. Sounds and behaviors were recorded on all devices. So a wealth of data to sort through (did you know that 90% of this work actually occurs on shore).  A great day. We'll update you on the details in the next few days.

Aran with the Drifter after its first successful deployment.

Max recovering the towfish.

Day 15: Calm Waters, Calm Dolphins

Three rough-toothed dolphins. (Photo: A.J. Milette-Winfree
permit # 15530 to CRC)

We had glassy Beaufort 0 – 1 waters for a good part of our day today. This type of water is ideal for finding difficult to see, far off marine mammals. Our two research vessels searched these waters for a combined 263 km. While we did not find melon headed whales or our ever elusive false killer whales, we did have a unique encounter with a group of rough-toothed dolphins (Steno bredanensis). When sighted off of the Big Island, these dolphins are often evasive, making photo-id and tagging a very difficult endeavor. Today however, this pelagic and poorly known species gave us a great opportunity to collect a wide range of data. We were able to photograph each individual in the group, record their acoustic signals using the towfish, and collect 2 biopsy samples for genetic analysis. This was our best towfish recording yet, giving us a wealth of echolocation clicks which will add to our growing catalog of rough-toothed dolphin signals. Renee Albertson of Oregon State University, who is part of our research team, was particularly thrilled with our data collection today. The biopsies and associated data we collected will provide her with valuable data for her PhD research on rough-toothed dolphin population structure.

Tag on, Tag off

A nice, successful tagging event and a good day overall. We had a long encounter with a group of pilot whales. During this time we successfully placed a suction-cup DTAG on a pilot whale. It was a good solid 'stick' by the tagger, Daniel Webster.  The tag stayed on for the pre-determined time of an hr.  After that hour, it properly released (when the whale was next to the boat, of all places). We easily picked it up in a net, downloaded the data and there are some nice pilot whale communication whistles, which we will upload to the blog in a day or so.  This was the first successful attachment of this new DTAG3v.2. Super exciting for us!  All parts worked. It also helps confirm the likely malfunction of the previous tag (that the release and recording programs on the tag were likely reset when the tag was caught was between two whales bumping into each other). 

Daniel about to put the DTAG on the pilot whale. (Photo: T. A. Mooney
permit # 15530 to CRC)

In addition to this awesome event, we also placed the towfish in the water near five Feresa attenuata (pygmy killer whales) and recorded some cool echolocation clicks from a species rarely studied. All in all, a great day for the project.

Max proudly recovering the tag.

Day 13: The search continues

Pilot whale
(Photo: T. A. Mooney
permit # 15530 to CRC)

Both yesterday and today we were forced to turn south after trying to steam north on the leeward side of the Big Island because of weather. Sea states of Beaufort 3 or 4 (breaking waves and whitecaps) make the ride uncomfortable for us on boat the boat, but more importantly, it makes spotting whales even more difficult (for more about the difficulty spotting whales, see here for a recent blog post by Alexis Rudd, a biologist who was helping us out last week).

Just before noon today our other research vessel sighted a group of pilot whales and we arrived shortly thereafter to attempt to attach another ECG tag to a large adult male. The whales were cooperative, but for some reason the tag didn't attach. We quickly brought the tag back on board but damage prevented another try, so we kept steaming south.

Attempt to attach the ECG tag to an unwitting pilot whale
(Photo: T. A. Mooney, permit # 15530 to CRC)

Our second and last encounter of the day was with more pilot whales. Their behavior was interesting so we deployed the towfish to record for around 15 minutes, and continued our search but were not rewarded for our efforts with any further sightings. With the challenges posed by the weather this field season the towfish has been a crucial acoustic tool, which allows us to get acoustic recordings of the animals even if we can't get close enough to tag them. Ideally, we can have data both from the towfish and the DTAGS. Wind looks like it will be a little better tomorrow, so hopefully we will have an easier job of spotting our targets.

Spyhopping
(Photo: T. A. Mooney, permit # 15530 to CRC)

Day 11: "Those are peps!"

Two of the melon-headed whales we were with yesterday
(Photo: T. A. Mooney, NMFS permit # 15530 to CRC)

The wind had calmed down and so we headed north. Early into our steam we encountered, for the first time of the trip, one of our study animals, the melon-headed whale (Peponocephala electra), or "peps". Typical group sizes for these animals in Hawaii are 100-200 individuals, but we only found a few, spread out animals. Things got complicated when, in following the peps, pilot whales and rough-toothed dolphins (Steno bredanensis) started popping up everywhere. But we eventually found the peps and followed them away from the mix. Associations between these three species are not uncommon, but make following a focal species difficult. We stayed with the peps for nearly 5 hours, but it turned out to be an uncooperative group, and we couldn't get close enough in the boat to put a tag on. Instead, we got some good towfish recordings of clicks and whistles. Today we head north again. Now that we've found our study animal, it's time to get some tags on (and then get the tags back).

Day 10

Our hopes for recovering our lost tag were temporarily revived today when  we sighted the University of Hawaii's research vessel Kaimikai-O-Kanaloa 30 km offshore and heading north. Aran called their bridge on the radio but after a follow-up phone conversation we were told they had engine trouble and were returning to Honolulu, and so were unable to search for the tag which, at this point, was probably nearly 100 km from our harbor and at least 50 km offshore in the middle of a windy channel. A quick survey of the charter boats in the harbor and a subsequent check on the radio signal, which had weakened overnight as the tag drifted further away resulted in us again halting the recovery plans. 

Aran using the radio tracking equipment
from land to search for the tag's signal
(Photo: M. Kaplan)

That bad news was slightly offset by the fact that we were able to deploy the towfish four times today, making a total of 50 minutes of recordings of the clicks and whistles of rough-toothed dolphins. And the weather appears to be improving: we plan to head north tomorrow morning in search of the as-of-yet elusive false killer whales and melon-headed whales.

Some times things go your way. And some times they really, really don't. Yesterday we put out two new tags on a nice, docile group of pilot whales. The first tag was an ECG tag. It collects heart rate information on diving pilot whales. It's a novel tag with incredible potential to learn how these deep divers can manage their extraordinary fast and deep dives.  This ECG tag was designed by Russ Andrews of Alaska Sea Life Center.

Suction-cup ECG tag about to be placed on a male pilot whale
(Photo: T. A. Mooney, permit # 15530 to CRC)

The second tag we put on in the group was the new DTAG3.2. It was our first deployment of this tag. We were aiming for short and sweet 2 hr deployment to test our equipment and procedures. It is supposed to release its suction-cups after a pre-programmed amount of time.

A suction-cup DTAG3 on a large male pilot whale
(Photo: T. A. Mooney, permit # 15530 to CRC)

Unfortunately, both tags stuck a little too well. The DTAG didn't release on time, nor did the ECG tag. They stayed on the whales a few extra hours and this was long enough for the whales to swim north and offshore, away from us and into the current. The tags finally released far off-shore, and are still being carried away by the current. Amazingly, we can track the tags movement away from the islands. But the winds remain strong and the waves are large and we can't safely catch up with the tags right now. We'll follow the tags progress; the ECG tag has a satellite transponder and the DTAG through its radio beacon. We will keep you posted. And it's a big ocean. Please keep your eyes out.

One week down

One week down. A fair amount of acoustic data, but not from our target species. The strong trade winds are holding us back from heading up north to the 'hotspot' areas where we are most likely to see melon-headed whales and false killer whales. We traveled north for a short while today but were pushed back by strong winds and 10' seas.

Two pilot whales
(Photo: T. A. Mooney, NMFS permit # 15530 to CRC)

Heading back south, we encountered a group of pilot whales. We deployed the towfish withe DMON acoustic recorder (we now call the system the DFish) and recorded some great sounds. This group had about 4 young animals in it, including 3 'young-of-the-year.'  These are animals that are born this year. They were a quite a helpful group that allowed us to record some social sounds, perhaps between the mom-calf pairs, or to coordinate diving. We hope to address who is making the sounds (and why) as we analyze these data in the upcoming months.

Day 6: More acoustics, and more wind

Two spotted dolphins
(Photo: M. Kaplan, NMFS permit # 15530 to CRC)

The weather has taken a turn for the worse and has prevented us from heading north to our study species' habitat, so we headed south out of the harbour today and encountered pilot whales, spotted dolphins and more rough-toothed dolphins.

For the rough-toothed dolphins we deployed the towfish to make more acoustic recordings of their echolocation clicks. But we had yet to see for ourselves how the towfish behaved in the water, so we donned our masks, fins and snorkels for the second day running to do some in-water tests. The result? The towfish looks great, and the acoustic data that we are collecting with it somewhat makes up for our inability as of yet to tag any false killer whales or melon-headed whales. We're hoping for better luck and less wind over the next couple days.

The towfish in water, with the DMON (yellow) attached below
(Photo: T. A. Mooney)

Day 5: "It's a whale... shark"

The whale shark (Photo: T. A. Mooney)

"Get your mask fins and snorkel, get in the water quickly and try not make a splash," said Robin as we approached a 17ft juvenile whale shark several kilometers offshore. The morning had, up until then, been mostly uneventful, with one early sighting of bottlenose dolphins followed closely by a pilot whale sighting. We had tried to steam north but the weather had significantly deteriorated and we quickly turned back, after getting a report of a large group of whales around the harbour. Once back around the harbour though we didn't see anything, so we continued to travel south. Around 11:00 am, Robin spotted something in the distance from the flying bridge and we approached. From a distance, the fin protruding from the water made it clear that it was a shark but only when we drew close to it did we realize it was a whale shark.

We quickly but cautiously piled into the water, afraid that the slightest splash could send it on its way. But it stuck around for over 20 minutes as we swam with it, and it was us that eventually had to get back on the boat to continue our work while it continued to swim around us.

The whale shark (Ryncodon typus) is the largest living fish and yet it eats some of the smallest animals in the sea, primarily plankton, by filter-feeding. It's giant head is mostly mouth, but in spite of this shark's size it is docile and can manoever its body gracefully using its ability to sense movement in the surrounding water. Not exactly the kind of whale we are looking for, but a rare encounter that made our day.

Other sightings

We don't always just see dolphins and whales.  Today was a good day for sighting some other ecologically key species. We spotted an oceanic white tip shark and a deep water squid. The squid was dead and partially consumed, floating on the water's surface. It was likely brought up from the depths by a deep diving cetacean such as a pilot whale or beaked whale. Sometimes we find these squid by sighing birds sitting on the water, feeding on the squid. But this one was simply floating at the surface and we happened to drive by it in our boat. We pick up the squid with our sample net, place it in a labeled ziploc bag and it will be shipped to Seattle for genetic identification. Notice all the little fish that make floating items like this their home.

A lost squid meal floating at the water's surface with small fishes using it as a temporary home.

 
Several hours later we spotted the ocean white tip. It also had a large school of fish associated with it (not visible in the picture). In this case, there were larger fish that were below the shark, perhaps feeding small leftovers from the sharks meals.  Both the squid and shark are key links in the ecology of the system here in Hawaii and elsewhere. Squid are a vital link between top predators such as sharks, cetaceans, birds and game fish, and the squids smaller and more abundant pelagic and mesopelagic prey. Sharks are the top of the food chain and sentinel predator species that are often over fished.

Oceanic white tip reef shark.

Day 3: Pilot whales (again and again) and a rare sighting

Pilot whales
(Photo: M. Kaplan, NMFS permit #15530 to CRC)

Today was the longest day on the water yet. We covered around 160 km and had 4 sightings, 3 of which were of pilot whales. In fact, we've seen so many pilot whales over the last couple days that tonight over dinner none of us could actually remember our second encounter of the day, which was, of course, more pilot whales. Memory starts to go and events blend together when you spend long consecutive days on the water, which is why recording sightings and all of the associated data right at the time is so important.

Aran (l) and Daniel (r) photograph pilot whales while Robin (center) manoevers the boat and Jeff (bottom) records sighting data (Photo: M. Kaplan)

Our third sighting of the day was of Risso's dolphins (Grampus griseus), which are infrequently seen around Hawaii and very rarely seen in the numbers we encountered today (around 40 individuals). We got around 15 minutes of good acoustic recordings from the towfish - lots of clicks. Unfortunately, this species isn't the most cooperative so attempts to satellite tag an individual were unsuccessful. Even though we haven't yet seen our two main focal species - false killer whales and melon-headed whales - we've still been collecting some good acoustic recordings. And hopefully, if the weather cooperates, in the next few days we will be able to head north out of the harbour on the leeward side of Hawaii, where these species are more frequently encountered. To prepare for that, we have finally got the drifter buoy working.

Two Risso's dolphins with characteristic white scarring on the body
(Photo: T. A. Mooney, NMFS permit #15530 to CRC)

Day 2: Got some sounds!

Spotted dolphins
(Photo: M. Kaplan; NMFS permit #15530 to CRC)

Yesterday's low sightings numbers were more than made up for by this morning. Not 15 minutes after leaving the harbour did we catch a group of pilot whales, followed shortly by a few bottlenose dolphins (Tursiops truncatus). An hour later we came upon rough-toothed dolphins (Steno bredanensis), and then, a large group of spotted dolphins (Stenella attenuata). In total, we had 9 sightings today of these four species while travelling 126 km. 

Spotted dolphin with a "cookiecutter" wound from a cookiecutter
shark bite (Photo: M. Kaplan, NMFS permit # 15530 to CRC)

While we didn't find the species we are looking for, this cetacean abundance let us try out the towfish for real. It was deployed 3 times for a total of 45 minutes of recording, split among rough-toothed dolphins and pilot whales. Once back on land, we had a look at the recordings and found lots of clicks and some whistles. So the towfish is looking good. Now to fix the drifter buoy once and for all...

Spotted dolphin (Photo: M. Kaplan, NMFS permit # 15530 to CRC)

Spectrogram of two pilot whale whistles picked up by the DMON while in the towfish

Day 1: Pilot whales

Prepping the boat at 6:00am
(Photo: M. Kaplan)

Today was the first of 17 days out on the water. We left the harbour at 6:30am aboard the Wild Whale, a 27' Boston Whaler, and headed south in search of our target species.

Scanning for whales
(Photo: M. Kaplan)

As we were leaving the harbour, Robin Baird, one of our collaborators from Cascadia Research Collective, described the method of scanning the water for whales. Each of us on board was given a section of the boat - for example, from 12 o'clock to 6 o'clock - to survey for the day. So the 7 people on board were each responsible for an area, which overlapped with someone else's designated area.

When someone spots a whale, they shout out the location, distance from the boat, number of animals and the direction that they are heading in. And then everyone springs into action, some people grabbing cameras to take close-up shots of dorsal fins for photo-ID catalogues while others pick up the clipboard to record the sex, number and estimated ages of the animals, and others still picked up long poles with waterproof video cameras attached to film the whales underwater as they get close to the boat.

Around 11:00am our scanning efforts were rewarded: we came across a group of around 30 pilot whales (Globicephala macrorhynchus) and immediately got to work. We stayed with this group for just shy of half an hour, and then moved on in search of other species.

A pilot whale "spyhopping"
(Photo: T. Aran Mooney, NMFS permit #15530 to CRC)

Unfortunately, as they day continued the weather started to deteriorate with big swell and whitecaps, which makes sighting whales very difficult. On our return to the harbour we managed to try out the towfish for the first time, which, after we managed to untangle its rope, worked rather well.

In all, we covered nearly 150 kilometers of tracks, but we only managed to see that one group of pilot whales so have yet to make any acoustic recordings.

I included some of the video here that I shot using a GoPro in an underwater housing - unfortunately the quality has been degraded by uploading it, but I am working on putting together a clip with more footage. We hope to use this system to look at how animals react to being tagged and potentially to follow false killer whale predation of fish at the surface (Video: M. Kaplan, NMFS permit # 15530 to CRC).

Once back on land we got straight to work prepping the DTAGS and DMONs for tomorrow and again trying to fix the drifter buoy. Almost there, I think. We have two boats tomorrow, which should improve our chances of seeing our target species.

Day 0: Prep for the field and some quick-thinking solutions (almost)

Our first day in Kona and the only one before we head out on the water, so we spent the day getting our equipment together and picking up the last few items we need.

View from our apartment

On this section of the project we are using two types of acoustic recorders - the DTAG, which we attach by suction cups to a whale for up to a day, and the DMON, a passive acoustic recorder. The DMONs will either be towed behind the boat in a "towfish" or drift passively underwater, attached to a floating buoy, depending on the behavior of the animals and our research objectives. One of our tasks to get ready for tomorrow was to seal the floating buoy to protect the electronics inside that allow us to track and retrieve the DMON once it has been deployed.

The DMON

Unfortunately, only after it was sealed up did we realize that the electronics weren't working. We took it apart again only to realize that a crucial switch had been damaged during shipping. A number of potential fixes were discussed until Aran came up with the idea to use a door alarm. So after trekking around Kona for nearly four hours and trips to RadioShack, Home Depot, the drugstore and about 5 other places, we had everything we needed to put together a quick fix. Eventually we got our makeshift switch working, only to have it break as we were putting the lid on the buoy. Hopefully tomorrow we get it right the first time.

A fleeting feeling of victory

This evening we met up with some of the other members of the field team but had to leave early to finish up our prep. Forecast suggests that there won't be much wind tomorrow and we plan to meet tomorrow at 5:45am to take advantage of the favorable weather.

Equipment all ready to go for tomorrow morning

A new field season

Well, we are on our way to Kona Hawaii again.  We are starting a new field season in two days.  This will be the third of four field expeditions to tag false killer whales and melon headed whales. I am writing this as we take the bus to Boston Logan airport.  Heading on this trip is Aran, as well as Max Kaplan.  Max is a new WHOI-MIT joint program graduate student starting in our SPASE Lab this fall.

So stay tuned! This is a 3 week project with high hopes.  We will keep you posted on the progress.