Cetacean Season 2015

Deep Sea News (Nov 16, 2015)

With the towed array deployed 24 hours a day, we have been constantly listening to the sounds of the sea. This is our Deep Sea News. We can hear our propeller and a little cavitation every now and then and anything else we hear or see on the screen, we deem as natural (earthquakes etc.,), biological or man-made. When you look and listen, you can work out what is what. Twenty-four hour monitoring brings the sound into you. A huge ore carrier (around 330m long) headed for China, overtook the sound-scape for over an hour.

Rest Spot? This Great Frigatebird has designs on our flybridge. With 250 nm to go to Cocos, that juvenile will be exhausted upon arrival. Where have the two Frigatebirds and about 20 Sooty Terns been?

Today, we heard sperm whale clicks, dolphin whistles, a possible dwarf sperm whale (known from a Scott Reef encounter) and peeking our interest, a mystery animal that moved from “seeking mode” to “hunting mode” using three different rates of sound pulses. The first sound pulses were 1-2 seconds apart (perhaps a “seeking mode”) for a couple of minutes and then the pulses became more concentrated with 10 pulses per second. Next, the pulses became even more concentrated with approximately 20 per second – appearing on the screen these pulses were much like the broad and fine teeth on a hair comb.

Towed Array Out. Listening 24 hours a day with the array, we have the Deep Sea News beamed live.

With 10-13 knots of SE breeze and 6/8 of cloud cover, surfacing cetacean bodies would appear dark and silhouetted as we headed into the glare. We have had very good sighting conditions all day. From inside the wheelhouse, my eyes were on stalks. I had half an eye monitoring the screen and the other one and a half eyes (you can imagine my scattered look!) scanning the horizon for the possible perpetrators of the interesting noises. We had a pleasant 29.1⁰ C air temperature on deck while Sam diligently scrubbed Whale Song to get rid of all the phosphate dust kindly shared from the mine at Christmas Island.

Hunting Call. A mystery animal is hunting. We hope we will see at least one of these animals.

Travelling across water more than 5000m deep, makes one think more deeply… perhaps, or perhaps not.

Deep Ocean Bliss

Deep ocean bliss

Deep, sea abyss

Currents in motion

Towards a different ocean

Cetaceans – international travellers

Singing humpback revellers

Across open oceans

Following the motions

Breeding time

Each wintertime

Find a friend

Energy extend

Then migrate to the poles

En route switch roles

From concentrated breeding

To concentrated feeding

In co-operative groups

Not competitive dupes

Among iceberg fog

To krill patches jog

Blue whales call across the seas

Reporting “cafes” to their cronies

Deep ocean hum

Not joyous to us, but sort of glum

Ocean full of sound

Noises of species found

At different frequencies

Great species efficiencies

Ocean callers

Bay wallowers

Their ocean home

Free to roam.

(Written by Micheline Jenner)

Sunset Goop. Biomass that comes to the surface in a daily vertical migration each night is targeted by cetaceans. This goop has a way to go!

Here’s to hoping we hear more wonderful critters tonight on our Deep Sea News.

Take care.