Commotion in the Ocean

Visibility in the ocean is relatively weak, especially at a depth of 400+ meters, making vision rather useless in the deep sea where whales reside. Sunlight doesn’t travel very far into the ocean. However, acoustic vibrations travel faster and farther in water than they do on land (Image 1). Therefore, sounds are valuable tools in deep, dark environments where whales use their ears as their eyes.

Image 1: An image by NOAA. A visual representation how far low-frequency sounds travel through the ocean.

Animals in marine environments rely on sound for basic survival needs. For example, baleen whales, which are the largest of marine mammals (including humpback, blue, fin, right, and gray whales, etc.) emit long, low-frequency sounds ranging from 7Hz to 22kHz that travel long distances across the ocean. Baleen whales also travel long distances making periodic migratory trips from their feeding grounds to their breeding grounds. Thus, scientists hypothesize that baleen whales use low-frequency sound in part to aid in navigation and long-distance communication.

The ocean is already a naturally loud environment, and humans have significantly increased that noise level. Anthropogenic noise pollution (such as ship traffic) obscures animals' communication, and could potentially have adverse effects on marine life; especially baleen whales (Image2). Although, considerable scientific uncertainty remains. Many factors influence the degree of impact, including multiple characteristics of the sound, and the animal. Potential impacts include behavior alternation, temporary hearing loss, and various communication interferences (Image 3).

Image 2: An image by the University of Rhode Island. A visual representation (in frequency (Hz)) of how anthropogenic noises interfere with marine mammals. Baleen whales' sounds are masked by seismic, ship traffic and bubbles & spray noises.

Image 3: An image by SSPA. A visual representation of anthropogenic noise interference with marine animals.

Scientists study sounds and their relationship with the environment over a wide range of scales (both spatial and temporal) via a new science called ecoacoustics. They investigate sounds to understand their evolution, functions, and properties under environmental stressors and changes. Sounds are used as tools to monitor ecological factors, such as biotic and abiotic relationships, and animal behavior, diversity, abundance, distribution, etc.

Using hydrophones to record marine acoustics have helped scientists gain knowledge, and a better understanding of the ocean and how we’re affecting it. We are proud to say our Wave Gliders (WGs) don’t produce noise that’s harmful to whales or other marine life. So far, we think WGs do not deter animals: fish aggregate around them, birds rest on them, whales swim near them, and dolphins bow ride them. The WG has revolutionized the way we collect data and monitor the ocean. The hydrophone we attached to Europa is gathering acoustic data 24/7 through which we hope to gain more knowledge and understanding of the sea. Additionally, we expect our data will create a baseline, and contribute to marine ecoacoustics, as well as, support conservation efforts and the management of marine resources.

Europa Update:

Europa is approaching our second seamount; we’re within 25 miles! Stay tuned for a seamount update, the ecology of seamounts, and the habitats they provide in our next blog.

A Whale of a Tale

We have a whale of a tale to tell you! Whale actually, we just want to tell you about our HUMPACS presentation at Whale Tales. Every year since 2016, whale lovers from around the world gather at the Whale Tales event on Maui. Hosted by Whale Trust (our HUMPACS partner), this event allows world-renowned scientists, photographers, filmmakers, and conservationists to share and discuss their work and latest research with the public through captivating talks, receptions, and exciting whale watches. This year’s presenters were terrific.

On February 16th, our HUMPACS project manager and VP of Hawaii Operations, Beth Goodwin, flew over to Maui to present our HUMPACS project with Dr. Jim Darling (Image 1). Beth has given talks at Whale Tales a couple of times within the past few years on JRF Wave Gliders and her humpback research. We are honored to participate in this memorable event, and it’s a great way to impart current scientific discoveries and research to the public.

Image 1. Beth Goodwin and Dr. Jim Darling presenting HUMPACS. The slide consists of our team members, Murray (left), and Adam (right), assembling Europa.

In the U.S, a significant gap in opinion exists between the general public and scientists on a wide range of science-related topics. The difference is partly due to the lack of STEM education in grades K-12, which creates a population that is scientifically illiterate. Science can be hard to understand if one is not familiar with the scientific method and the language scientists use, thus resulting in mistrust and misunderstanding of scientific data. Therefore, communicating scientific matters to the public can be a challenge. 

Whale Tales is an event that contributes to bridging this gap because presenters convey their research via engaging media presentations, storytelling (tales), and discussions from which the public can gain knowledge that’s been modified to be intelligible. Additionally, the event creates a way for scientists to present their work to their colleagues and professional peers. This allows the scientists (and other presenters) to receive feedback on their research and engage in discussion, which enables them to improve their work.

After her presentation, Beth, and Dr. John Ford volunteered to be naturalists on one of the whale watches where they were able to share their knowledge about humpback flukes and photo identification (Video 1). It’s not a fluke that they saw so many whales! Humpback whales have unique pigment patterns on their flukes (tails). Researchers compare fluke pictures to identify individuals. In 2007, Cascadia Research completed the SPLASH Project, which compiled thousands of fluke photos from numerous researchers with the purpose of determining population size within the entire North Pacific basin. 

Video 1. Beth Goodwin and Dr. John Ford talking about humpback whales on a whale watch. Video by Bryan Berkowitz

In other news, On Feb 19th, Europa made her way to the first seamount! Once there, we had her swim in a circle around the seamount for a few days while we listened to audio snippets. We’ve heard some unusual noises, but nothing that confirms the presence of humpback whales. So, we will persist forward. Our next target is a chain of seamounts within the outskirts of the Baja California Seamount Province (Image 2). It’s approximately 660 nautical miles away and will take about 18 days to arrive; between March 10th-13th. 

Image 2. Our next target: a chain of seamounts.

On Feb. 21st, Oceans Deeply interviewed Beth and wrote a compelling article about our mission. This media outlet is an excellent source for current ocean discoveries, and they’ve written numerous articles about Wave Gliders. 

Stay tuned for more updates!
 

Building our Acoustic Payload

Searching for humpback whale vocalizations in the middle of the Pacific Ocean is sort of like searching for a needle in a haystack. So, how do you search for a needle in a haystack? You build a sophisticated audio payload and keep your fingers crossed. Luckily our needle is a loud one!

The construction of our acoustic payload required a lot of software and hardware engineering because we wanted our hydrophone to detect whales from miles away, and keep data from being lost in case of an accident. Consequently, we acquired a “smart” digital hydrophone (HP) called the Ocean Sonics icListen 200 kHz, which can record a wide range of frequencies and target most cetaceans (Image 1).

Image 1. Ocean Sonics Hydrophone

Many mishaps could occur to a dangling HP in the middle of the ocean, hence we attached the HP to Europa’s sub to ensure we wouldn’t lose it to entanglement or predation (Image 2). However, the self-noise of the sub is relatively loud, and we found that it interfered with the acoustic sampling. Therefore, we embarked on a design to decouple as much of the sub noise as possible and enlisted the help of an acoustician, Mike Holt, who has built similar devices his entire career. He helped us make a mount that would be durable but not too heavy, biofoul resistant for the several months mission and allow sound transference to occur. To construct this, we used a thick-walled 3” type K copper pipe, which is an excellent biofoul deterrent and provides mounting strength. We mounted it to the center of the sub so that it did not add drag or change the pitch of the sub (Image 3).

Image 2. Pelagic white tip shark chasing an entangled Wave Glider

Image 3. Hydrophone mounted to center of sub

To mask the mechanical noise, Mike first designed an inner casing tube out of low-density polyethylene into which the HP would slide. To keep it from hitting the bottom or the sides we manually cut 15 donuts of 10 pores per inch by 0.75” thick polyurethane open cell foam to encase the HP. We then sealed the tube and filled it with medical grade castor oil, which is well matched to the impedance of seawater. After testing it for leaks, we slid the inner casing into the outer copper pipe modified with 250 drilled holes. The holes enabled the interference to be no greater than 12th lambda of the highest frequency of interest (Image 4).

Image 4. Murray and Beth building hydrophone casing

Overall, the entire process was painstaking but worth the effort to boost our chances of finding our needle in a haystack.

For question, please email HUMPACS@jupiterfoundation.org

Europa’s Super Blue Blood Moon Photos

The Super Blue Blood Moon was a sight to see! Don’t you think so? Many awoke in the early morning hours to watch the moon turn red, and those who missed it were able to view stunning photographs of it on the internet. Amazing photographers from all over the world captured shots of this ‘once in a blue moon’ event.

On January 30th, from 6:15 p.m. to 7:15 p.m. HST with location coordinates of 18.99°N, 149.50°W, Europa was able to capture a photo series of the moon rising! She wasn’t able to catch the moon when it turned red because it was too high in the sky. We only had a short window (an hour) of when the moon was in the camera view. Even so, the pictures are remarkable, as they are likely the only pictures in the world captured that night by an autonomous ocean vehicle (see image series below). In the first photo of the series, it was still light because the sun had just set. As the moon rose, the images became darker but then lightened again as the moon rose further into the sky because of its brightness.

To obtain this image series, we calculated the trajectory, angle, and rising time of the moon relative to Europa's location. We then steered Europa to face the right direction where the camera could capture the moon rising in front of her. During that hour (starting at 6:15) we set the camera payload to take a photo every 15 minutes, totaling five pictures.

Who knows what will be taking pictures of the next Super Blue Blood Moon on January 31, 2037!

For questions, please email HUMPACS@jupiterfoundation.org

Mahalo!

Deploying Europa

On January 15, 2018, we successfully deployed our Wave Glider (WG), Europa, to embark on our most ambitious mission to date, HUMPACS (Humpback Pacific Survey). It was a beautiful day when we launched Europa; the wind was relatively light, and the sea state was calm. Conditions such as these enable a smooth process of loading and unloading WGs from our 32 ft boat, the May Maru.  

Our team worked for a year to prepare Europa's payloads and ensure her success during the three-month mission at sea. Thus, we celebrated the triumph by pouring a bottle of champagne over Europa before letting her swim away (see video below). Please note that we drank what was left of the bottle after working hours! Once deployed, a school of dolphins joined Europa; bow riding and spinning while escorting her out to sea (see video below). We perceived this as a good omen to our cetacean mission!!! 

We deployed Europa off Puako, the northwest coast of Hawai'i Island. As she made her way around South Point, the southernmost tip of the Island (and the USA), strong currents from a big winter swell kept pushing her off course. This was a little discouraging because Europa was only a few days into her mission and we didn't want her to go astray. Nevertheless, Europa pulled through and she’s making impressive progress, averaging ~1.5 knots. Europa is scheduled to reach her first seamount anywhere between February 18th-21st. Track Europa's journey here.

Europa is transmitting multiple data types to us via satellites, in real-time. Some of the data are available to view in our Data Portal. We just assembled a graph of daily sea surface temperature (SST) means that will be updated periodically to display recent data. An additional SST logger called a HOBO, which is more precise, is attached to Europa but its data can't be accessed until the mission is complete. Stay tuned for more updates!

For questions, please email HUMPACS@jupiterfoundation.org

Mahalo!