The Sound of Silence

Each year, we have made significant improvements to the audio quality of our HUMPACS payload.

From the first year HUMPACS EAST in 2018 to HUMPACS WEST in 2019, we dropped the hydrophone mount ~4” to help isolate it from the sub. This dramatically improved the amount of noise we were getting from the rudder and the wing stops and even allowed us to not have to filter out so much of the rudder noise (see our Can You Hear Me Now blog).

For HUMPACS PMNM 2020, we again made more improvements, this time to the sub itself, by adding washers and high-density rubber pads to strategic locations (see our Europa Arrives in the PMNM blog).

For HUMPACS MEXICO 2021, we again mitigated more of the self-noise sub sounds which has significantly improved our audio quality.

Here is an example spectrogram of what the whales sounded like from the improved system as Europa left Puako for HUMPACS MEXICO. We are thrilled with the quality!

Land Ho, Land Ho!

Europa has finally made it home and was safely recovered March 14th. This type of survey throughout the pristine Papahānaumokuākea Marine National Monument has been the first of its kind. We are very proud of the mission and collaboration with the Navy and NOAA Sanctuary. Thank you all for following Europa’s journey.

Europa’s course navigating outside of the 200’ depth contour (red circles) throughout the PMNM

Europa lays eyes on the Kohala Coast and Mauna Kea on the Big Island

Europa with view of Mauna Kea: Land Ho!

View of Europa from the May Maru

Europa, moments before recovery on the May Maru

Given the current Covid-19 pandemic, Europa follows appropriate bio-security protocol

She's not sure about coming to shore after her journey in the pristine, uninhabited, PMNM. Please stay safe!

Recovery crew: Beth, Maya, and Jessica (from left to right)

Homeward Bound

Europa is on her way home after successfully surveying The Papahānaumokuākea National Marine Monument. As she exited the monument, she concluded with a cross through, and circle around, Middle Bank.

We expect to recover her in Puako sometime in the next 5-7 days, but the journey is not over yet. For this last leg, Europa has been faced with strong winds and high seas, as well as had to dodge a number of cargo and passenger vessels.

Today, a passenger vessel from the Bahamas, headed to Oahu, passed behind her. The vessel’s name was Europa, a good omen we hope!

The entire team from Jupiter, NOAA and the Navy anxiously await her recovery.

Stay tuned!

Europa passing through, and then circling, Middle Bank at the end of her PMNM journey.

A look at all of the marine traffic that Europa is avoiding on her way back home to Puako. Each of those yellow and red dots represent a cluster of vessel breadcrumbs.

Europa vessel that passed by our wave glider Europa earlier today.

Sunrise from Europa in some heavy seas.

Moonrise (supermoon) from Europa with waves crashing.

Phew…We Made The Crossing!

The Alenuihaha Channel that lies between the Big Island of Hawaii and Maui, is considered one of the most treacherous channels in the world due to the strong winds and high seas that funnel between the two islands’ narrow pass (~26 nm). In the Hawaiian language, alenuihaha means "great billows smashing”, and that it is!! On the day we originally tried to launch Europa, Jan 6th, we were experiencing gale force winds, with gusts over 50mph. We stood by monitoring the weather hourly and were finally able to find a break in the weather on Jan 8th, and successfully launched Europa. However, we were still experiencing gale force winds and seas over 15ft. We decided to not have Europa cross the channel directly from Puako but instead to send Europa 30nm south, off Kailua Kona, in hopes of getting out of the strongest funneling affects. Nonetheless, Europa still faced gusts over 50mph and seas over 15ft. The video below from Windy shows the wind gusts for the channel and Kailua Kona.

Forecast of the extreme sea state that Europa had to travel through at the start of it's journey at the Papahanaumokuakea Marine National Monument. Follow th...

Another reason we sent Europa south to cross the channel is that this avoided crossing the densest part of the shipping lanes coming in and out of the state’s ports. Map below shows the vessels and Europa as the yellow star.

While she had to dodge several ships, there was one encounter that was quite close. When this happens, we get “Proximity Warning” alarms sent to our cell phones (25 of them in the middle of the night!), notifying us of an oncoming ship. Below is the ship Azamara Journey, that was barrelling down on Europa at 15 knots.

Fortunately, Europa has anti-collision software that detects a ship several miles away and when it determines their paths will cross, she takes evasive action to alter her course until the ship has passed by, then gets back on course. At the time of crossing paths, they were 1nm apart (see map below).

Green breadcrumbs are Europa. Grey are Azamara Journey.

Europa’s first sunset

Europa taking on waves in the channel

Europa on a stormy day

For Immediate Release:

Autonomous (Robotic) Wave Glider Mission from Hawaii to Mexico Detects Humpback Whale Calls in Tropical Mid-Ocean and Questions Definition of Winter Breeding Assemblies 

Current NMFS humpback whale management policies assume Mexico and Hawaii winter assemblies are distinct with separate status and management warranted

BIG ISLAND, HAWAII July 1, 2019 – Jupiter Research Foundation and Whale Trust are pleased to announce the publication of the results of the first leg of their autonomous Wave Glider HUMPACS (Humpback Pacific Survey) acoustic survey in Journal of the Acoustic Society of America – Express Letters. During a 100-day nearly 7,000 km (3,800 nm) round trip survey on a line between Hawaii and Mexico within the 2018 winter breeding season, humpback whale calls were heard in mid-ocean basin, halfway between the known near-shore assemblies. 

“They’re not ‘supposed’ to be there,” says Dr. Jim Darling, Whale Trust biologist and project partner. Humpbacks are known to assemble in specific near-shore, relatively shallow, breeding grounds in Mexico and Hawaii. “But then no one has looked in these more remote, offshore areas either.”

Mission control was from Puako, Hawaii where Beth Goodwin, Jupiter Research Foundation VP and HUMPACS Project Manager, and her team were in daily communication with the Wave Glider: monitoring status, downloading surface and underwater photographs, downloading short samples of recordings via satellite, and making course alterations if needed. 

From January 16 to April 25, 2018, the Wave Glider, named Europa (after one of Jupiter’s moons), performed a 6,965.5 km, 100-day (RT) continual acoustic survey from Hawaii towards Mexico circa 20° N. The survey resulted in 2,272 hours of recordings and included over 4,000 cetacean calls.  Of these calls, 2,048 were identified as humpback whale calls.

The humpback calls were recorded up to 2,184 km (1179 nm) offshore spanning 30 days between January 20, when the Wave Glider left Hawaii, to February 23, 2018. On many days, multiple humpback call detections were recorded (up to 377 calls over 23 hours of a day). Actual numbers of whales cannot be determined, as one whale can make many calls.

“This was risky, we had no idea if humpbacks were even out there,” says Goodwin. “And then, even if they were, there were needle-in-haystack odds of intersecting them considering the size of the Wave Glider and the size of the ocean.”

Possible explanations, suggests Darling, include an undocumented migration route to Hawaii, a separate (from Hawaii and Mexico) offshore assembly of humpback whales, or travel between Mexico and Hawaii assemblies within the same season. At the very least, these results indicate an extension of winter distribution and habitat of humpbacks. It could also be that these offshore whales have not been included in current population estimates.

Since 2016, the model used by the U.S. National Marine Fisheries Service (NMFS) to manage humpback whale populations has treated the Mexico and Hawaii winter assemblies of humpback whales as distinct populations. As such, these populations have different status under the U.S. Endangered Species Act (ESA): Mexico humpback whales are considered threatened while Hawaii humpback whales have been delisted; that is, the Hawaii population has no protection under the ESA.

This assessment is further complicated by longstanding research showing shared song between the breeding assemblies and an interchange of photo-identified individual whales between these two winter breeding grounds.

Our findings question the independence of Mexico and Hawaii humpback whale populations and illustrate the huge potential for the use of autonomous vehicles in the study of whales across remote locations of the ocean.

“We feel certain our results will encourage more research, affect how humpback and other whales are monitored, and help with management,” says Goodwin.

The paper is online: https://doi.org/10.1121/1.5111970

BACKGROUND

Wave Glider

The Wave Glider (produced by Liquid Robotics, a Boeing Company) consists of a surfboard-sized surface platform (the float) tethered by an umbilical cable to a submerged glider (the sub) 8 m (26 ft.) below the surface. The float includes a command and control unit, three solar panels, an instrument package, surface and underwater cameras and communications systems. The sub is the propulsion unit, which transforms vertical wave movement into forward motion (https://www.liquid-robotics.com/wave-glider/how-it-works/). Time-lapse series of images from the two Europa cameras, surface and underwater, are accessible on the JRF blog:
http://jupiterfoundation.org/current/2018/5/22/f2l6bevguh177l21x42gi20pegicbv

About Jupiter Research Foundation

The Jupiter Research Foundation is a 501(c)(3) non-profit scientific research organization. Established in 2003, the Foundation is dedicated to conducting innovative scientific research and finding technological solutions to problems which are outside of mainstream science and technology. Our findings are shared with the public and academic community in hopes of better monitoring and understanding the natural world. Visit https://jupiterfoundation.org/ to learn more. 

About Whale Trust

Whale Trust is a Maui-based 501(c)(3) non-profit organization whose mission is to promote, support and conduct scientific research on whales and the marine environment and broadly communicate the findings to the public. Whale Trust research programs focus on behavior, communication and social organization of whales. For more information, visit https://whaletrust.org/.

HUMPACS East Results Are In!

We know you’ve all been waiting to hear about the success of HUMPACS East, and believe us, we’ve been just as anxious to let you all know.

Our results have just been published in the The Journal of the Acoustical Society of Amer (Vol.145, No.6).

The purpose of this study was to investigate if whales were present in the offshore waters between the Hawaii and Mexico breeding grounds where, to our knowledge, they have never been documented before. It’s a big ocean out there, so we were searching for a needle in a haystack…and we were successful!

We identified humpback calls out to 1,200nm from Hawaii, approximately midway to Mexico.

Our findings raise more questions regarding humpback whale breeding grounds, migration routes, and habitat. We have presented our results to the Marine Mammal Commission and hope to present at the World Marine Mammal Science Conference in Barcelona, December, 2019. We feel certain our results will elicit more research, affect how marine mammals are monitored and help with management.

Read the Publication (link to PDF)

Supplemental Material (link to download)

Copyright 2019 Acoustical Society of America. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the Acoustical Society of America. The article appeared in The Journal of the Acoustical Society of Amer (Vol.145, No.6) and may be found at https://doi.org/10.1121/1.5111970.

Below is a short annotated power point presentation of our mission and results.

Aloha!

Europa's NOT Drunk!

You may have noticed that Europa has been bouncing around a bit more than it did on HUMPACS East. Well don’t worry…it’s intentional!

The general path that Europa is following goes along 20^oN latitude.

The reason that it is not going in a straight line is because there are numerous seamounts and guyots (aka tablemounts) that we are having it navigate over on it’s way to the Mariana Trench.

Seamounts are basically underwater mountains that are at least 1,000m tall. They do not actually reach the ocean’s surface. Guyots are seamounts that did, at one time, rise above the ocean’s surface, but then eroded away, flattened out, and eventually sunk back down underwater.

Why does all of this matter?

Well, since Europa is basically a very small fish in a very big pond, we need to strategically look for these humpback whales. Even though most of the time the tops of these seamounts and guyots can be found many hundreds, if not thousands, of meters below the ocean’s surface, they are actually great producers of marine ecosystems. That makes us think that we might have a better shot at stumbling upon some humpbacks in those areas, as opposed to simply out in the middle of an even deeper ocean.

There has been some research to support the statement that humpbacks seem to frequent seamounts and guyots, though the exact reason why hasn’t been determined.

The leading theories are that the landmarks serve as resting and/or feeding areas, points for navigation, and even meeting grounds (source: PubMed Central®).

Maybe they’re sharing different versions of their song? At the end of the day, we don’t really know why…yet!

If you’d like to dive a little deeper into the science and evolution of a seamount, check out our blog post Mountains in the Deep Sea.

Figure 1: Europa’s path on a nautical chart. Europa is currently traveling from East to West, and navigating over many different seamounts and guyots. (Depths are in meters).

Figure 2: Zoomed in image to show more detailed depths of the Horizon Tablemount that Europa traveled over Jan 16-19, 2019.

Figure 3: Europa circling a particular seamount. We will have Europa do this from time to time to search a little more for humpbacks in areas we suspect them to be.

If you check out the HUMPACS page, you’ll notice that from January 16-19 Europa was cruising over the Horizon Tablemount. In another two or three weeks, Europa should be traveling around the HIG Guyot. This particular guyot is of note to us here in Hawaii because it was actually discovered about 37 years ago by the “Kana Keoki” research vessel, and named after the Hawaiian Institute of Geophysics (source: Marineregions.org).

So, for those of you that were wondering, and dare we say concerned, about Europa’s up and down path…worry no more! Europa is doing exactly what we want it to do, and we’re collecting lots of great data that we look forward to sharing later on.

Until then, keep checking in and watching Europa as it makes it’s way West across the Pacific Ocean.

Also, check out our live audio stream of the humpback whales that are swimming around Puako, HI right now!

Aloha!

Can You Hear Me Now?

When we were preparing for the first leg of HUMPACS, referred to as HUMPACS East, we found ourselves faced with a tough decision when it came to how the hydrophone should be mounted.

“Do we hang the hydrophone, or try to hard mount it as close to the sub as possible?”

When doing hydrophone operations just outside of Puako, Hawaii, we have found that you get the best audio if you hang the hydrophone at least 30 feet below the sub. This, obviously, is due to the fact that we’re basically decoupling the hydrophone from the sub. We also are able to pick up more sounds when we’re deeper.

Hearing that, you might wonder why we decided to hard mount the hydrophone during HUMPACS East.

Well, what we have also learned through years of experience monitoring the gliders off the coast of the Big Island is that when we have a hydrophone hanging, ocean currents become a much larger problem.

There are different currents at different depths, and so even though the glider (float, sub and hydrophone) are all relatively in vertical alignment, each part of them is getting pushed and pulled by a different current.

In Hawaii, it’s not that big of a deal for us because we keep the gliders in a relatively small area the majority of the time, and we can go rescue the glider if we really need to.

When sending it across the Pacific Ocean, it’s a different story. There are no rescue missions. It just has to work!

For that reason, we decided to keep the hydrophone hard mounted directly to the sub, with no separation or “acoustic isolation”. We knew that the background noise (flow noise, wing springs and rudder) would be very loud. However, we confirmed that even with all this loud background noise we would be able to detect humpback whales, as we did a proof of concept with humpbacks singing off Puako before sending it east. All this was worth it to know that the hydrophone would be very safe. After all, we’d never made this trek before, (no one had for that matter), so we didn’t know what kind of abuse it might encounter. Sharks, rubbish, wear and tear, getting tangled up by the umbilical. These were all big concerns, and, at the time, we needed to play it as safe as possible.

HUMPACS East

Copper Hydrophone Mount

All these concerns continued to stand true with HUMPACS West. We still agreed that the unknowns about drifting were too much of a risk, so we mounted it close, but not hard mounted.

Since we did not encounter any drift that could have entangled the hydrophone, nor any shark bites, for HUMPACS West, we decided to see what the minimum distance was that we could drop the hydrophone and achieve higher quality audio. We still needed to keep the hydrophone safe, but we wanted more vibration isolation between the sub and the hydrophone itself.

After testing many different materials and changing up the distance of which we dropped the hydrophone below the sub we came to the conclusion that a three inch drop using EPDM Fiberglass Reinforced rubber sheets to mount was the way to go. It improved our audio and also kept the hydrophone safe at the same time. As an additional safety measure, we added a deflector bar to the bottom of the sub to help prevent shark bites and entanglement on the hydrophone.

HUMPACS West

EPDM Fiberglass Reinforced Hydrophone Mount

Take a look at the two spectrograms below and see the difference in noise levels. HUMPACS West is exponentially more quiet than HUMPACS East. There is also almost a complete elimination of the 650Hz and 975Hz harmonics from the rudder module. This, alone, is a very improved piece of the puzzle, as the primary range that we listen and view the humpbacks’ song is in that <1KHz range.

HUMPACS West Spectrogram

HUMPACS East Spectrogram

As you can see, HUMPACS West is much more quiet as far as background noise goes. What’s that do for us? Well, if the background noise is less, then it becomes substantially easier to detect humpback whales (and other species). This improvement should greatly improve our post processing efforts, and is more efficient at detecting as many humpbacks as possible.

Currently, Europa is a little over 700nm (nautical miles) west of the Big Island of Hawaii. Follow its journey on the HUMPACS page!

Aloha!

We're Back!

Europa is back in the water on her second mission to listen for humpback whales, just in time for the Holidays. Last year, Europa successfully completed the East Leg (from Hawaii to the Baja California Seamount Province and back), and now she will swim to the Mariana Trench and back (the West Leg). Biologists have wondered if there is an undiscovered distribution of humpback whales among the seamounts between these areas. Since the East Leg was successful, we hope Europa’s journey west will be triumphant. You can track Europa’s path on our website. Stay tuned for more updates!

Wishing you a Happy Holiday and a Joyful New Year!

Photo Time-lapses from Europa

Almost one month has passed since we recovered Europa, and we are still in the process of analyzing data, however; we have reviewed all of our photos. During the 3.5 month mission, we had a camera attached to both the top and bottom of Europa’s float that took above and underwater images periodically on a daily basis.

The top camera was mounted on the back of the float looking forward, which enabled us to inspect the float and antenna deck during the mission. The bottom camera looked down towards the sub underneath the water to help us check the sub and umbilical. In the previous blog, we mentioned we had a gooseneck barnacle that grew over the underwater camera lens. Even so, we were still able to get glimpses of the sub for diagnostic purposes.

Over the 3.5 month mission, the top and bottom mounted cameras took over 500 photos each. We have constructed two time-lapse videos of the above and underwater pictures, which are each a little over three minutes long. We were able to capture some fantastic photos! The sunset photos and waves washing over the float are captivating, and it’s fun to watch the barnacle grow over time in the underwater footage.

In our next blog, we will post some sample of audio files of some exciting sounds we’ve heard, including odontocetes whistles and clicks, echolocation, and other unusual noises. Stay tuned!