2023

Aloha!

Once again, it has been a long while since we have update our Blog. However, we are very happy to announce the publication of our results from Europa’s 2021 Voyage to Isla Clarión, Mexico in Frontiers in Marine Science: Further evidence of humpback whale presence in deep tropical ocean during the breeding season: confirmation and extension of acoustic detection’s between Hawaii and Mexico! We hope you enjoy!

2023

Aloha!

It has been a long while since we have update our Blog. However, I am very happy to announce the publication of our results from Europa’s 2020 Voyage through The Papahānaumokuākea Marine National Monument in Frontiers in Marine Science: The occurrence of humpback whales across the Hawaiian archipelago revealed by fixed and mobile acoustic monitoring.

I hope you enjoy!!

EUROPA IS HOME!

On May 14th, after a 150 days at sea and over 5,000 miles, Europa finally made it back home from her journey all the way to Mexico and back! For days we had to stand by patiently and wait for her to round South Point to be in the lee of the Big Island for a safe recovery. When this would occur was all up to currents and sea state, as her speeds fluctuated between under a knot to over 2.5 knots as she approached. Finally at midnight on April 13th, Europa rounded South Point. Early morning calls were made and crew rallied to trailer the boat to Honokohau Harbor. We ran 50 miles in 2 hours to south of Miloli’i.  The first 40 miles were pretty mellow, but the last 10 miles, the seas got a bit rougher. By the time we reached Europa, who was about 6 miles offshore, we had wind gust of over 22 knots and swells up to 4 feet. However, the recovery went very well, and she looked GREAT! The whole recovery mission was over 100 miles round trip, hard on the crew, but nothing compared to what Europa had just gone accomplished!

Map of the Big Island. Green dots are Europa as she rounded South Point. Purple dots are of the May Maru as she traveled from Honokohau Harbor south to meet Europa. Purple and green are of Europa on the May Maru heading back to Honokohau Harbor.

What a Site For Sore Eyes! Europa after her 150 day journey! We are so pleased to have her back home safe and sound!

As expected, she had a few barnacles.

The copper housing for the hydrophone looked pretty clean.

She also had some unusual marks on two wings… possibly teeth rakes from some critter.

Of note, unlike all the other missions Europa has done, she had zero plastics stowed away! Perhaps the currents at 18°N latitude.

We are busy downloading the audio files. Next is several months of data analysis and paper publication.

what a relief to have her back HOME!

We made it to Isla Clarión!

We are extremely excited to report that this afternoon at 1250 HST Europa made it to within 5 NM of our eastern most destination, Isla Clarión, the westernmost and most remote of the Revillagigedo Islands. To date Europa has been underway for 84 days and traveled over 2300 NM!

Europa reaching her eaternmost waypoint, 5 NM away from Isla Clarión.

Below are a couple of pictures of the float taken from the stern end of Europa and a sub picture. All is looking very well.

Float pics from Europa. Not sure, but possibly can see Isla Clarión on the horizon 5 NM away.

Sub picture from Europa

She has turned around and is officially headed home!

Alphecca Seamount

In just few hours, Europa will be crossing over Alphecca Seamount, which is about 485 nautical miles SW of the tip of Baja California and only 120 NM from Isla Clarión. This is the shallowest feature she has come across since she left the Big Island. Europa will be going right over the top of the seamount which is about 156 meters (511 feet) deep. As Europa’s pilots, we are a bit nervous of currents or any fishing activity that could give Europa any trouble, but figure the risk is no greater here than anywhere else Europa has been over the last 3 months crossing the Pacific. As scientist, we are extremely excited to sail Europa over the seamount, which to our knowledge has not been surveyed before, and there is no telling what we will hear! You can track Europa on our map.

Alphecca Seamount from Biogeosciences Network

Alphecca means “the bright (star) of the broken (ring of stars)” and is the name of the brightest star in the constellation Corona Borealis, the Northern Crown. Alphecca is also called Gemma, the Latin name for gem or jewel.

Corona-Borealis  Constellation. Alphecca is the brightest star.

From Galactic- Astrology Blog:

“Alphecca is a star that reminds the quality of the planets Uranus and Pluto, and also the centaur Amycus. The symbolic image 'ring' refers to a situation or circular process that ends and starts again, repeating indefinitely ('limit cycle attractor' in the theory of dynamic systems). Therefore, the symbolic image 'broken ring' refers to interruption of this kind of endless processes; It is equivalent to the classic theme of the fairy tales of 'breaking the curse'.
Alphecca is related to the amazing experience of achieving what had been tried so many times.”

LET’S HOPE SO!!!

Another one bites the dust!

A mere 26 days after re deploying Metis with a new cable and hydrophone, and hearing fantastic whale song, the hydrophone once again was preyed upon! Is is really hard to tell if it is a shark or a barracuda, non-the-less, we are not sure why this is happening. The sea surface temperature has been about the same (78.8°F). We have had a Wave Glider equipped the same way, in these same waters every winter season for years, and never experienced this. This time we have a little audio to go with it. While there is no Jaws music in the background, it does sound like a freight train hit the hydrophone.

P.S. Europa is still happily cruising along and about 400 NM away from Isla Clarión, Mexico. More on this in our next blog.

Hydrophone cable with several rake marks.

Take a look and listen at the audio and spectrogram below of the exact time when the hydrophone got bitten off!

Clear Humpback Whale Song followed by either a shark or a barracuda biting off the hydrophone

Live Humpback Song - Puako, Hawai'i

Europa is doing fine and continuing to head towards Isla Clarión, Mexico. However, we wanted to update you on our wave glider Metis, who earlier this year was deployed off Puako to stream Live humpback whale song over our website. But on Jan 25th, the sound suddenly stopped. When we went out to investigate, we learned that some ocean critter, likely a shark, had bitten off the hydrophone! After a couple of weeks to do repairs and reassemble, we were able to re deploy Metis. Enjoy the audio and keep your fingers crossed no more predators!

Hydrophone cable bitten off presumably by a shark!

WHALE TALES 2021

Once again Beth will present at Whale Tales, along with many prestigious marine mammal scientists. More than 50 scientists, photographers, musicians, and videographers from around the world will share their knowledge to educate, inform, and inspire people of all ages at this year's virtual event. Please register for this amazing event. Visit whaletales.org to learn more and register.

WHALE TALES - A VIRTUAL EXPERIENCE - FEBRUARY 13-14

Woohoo! Half way to Mexico!

Last night Europa made a slight SE turn towards Isla Clarión, half way to Mexico (~1,100 NM). From the map you can see that in 2018 at this point Europa went more NE towards Baja California Seamount. Europa is now exploring all new acoustic ground!

Map showing Europa’s track and Isla Clarión, Mexico

We are using an Ocean Sonics icListen SB2 Ethernet digital hydrophone that has a sampling rate range from 1kHz to 512 kHz at a 16 bit depth or 1kHz to 256 kHz at 24 bit depth. Its frequency response is 10 Hz to 100 kHz +/- 3db or 10 Hz to 200 kHz +/- 4db. We are using a sample rate of 32 kHz at 24 bit depth, producing audio files with a frequency of 10Hz to 16 kHz to target humpback whales. We are storing .wav audio files onboard Europa 24/7.

We have been downloading approximately eight 30 sec mp3 audio files per day and have been getting some very clear humpback and minke whale calls. This validates that the humpbacks we heard in 2018, far offshore in deep ocean waters, were not a one-time only occurrence. This is very exciting.

Below is a sample spectrogram of humpback calls and a minke whale recorded offshore.

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!