Post the Thirty-Fourth

It's time for some more SCIENCE!

"Hearken ye to SCIENCE for, lo!  SCIENCE yet never sleepeth, even unto the completion of the voyage."  
 - Shakespeare, King Melvin III, Part IV





Meet Tasha Waller, Marine Research Aquarium Supervisor.

Swim-Swim makes a new friend.

Hi Tasha!


Tasha's mission (she chose to accept it) is to collect more krill (Euphausia Superba) for the Antarctic Division's krill aquarium .  The krill in the aquarium do in fact breed, but not in sufficient quantities to make up for natural loss and the use of eggs and larvae in research.  So periodically (every 2 to 3 years) there is trawling done in the Southern Ocean to collect more.

Tasha is here to conduct the aforementionated trawling, and your faithful correspondent is on hand to report.  Lucky, lucky, LUCKY you!

There were a couple of trawls done on the first day out of Davis, but things really got serious on that first night.  We reached the planned trawling area - an undersea bank that was only about 200m deep - at about 3am, and the Krill Team swung into action.  For safety reasons I was not permitted on the trawl deck during the operation, but I could see some of it from the helideck above.

(Please excuse the quality of the photography. More than usual, that is.  Although not fully dark it's quite gloomy at 3am and the camera struggled a bit).

Gull's-eye view,.  (Mine?  Mine?)

The ship slowed to 1 - 1.5 knots, and the Krill Team deployed the trawl net to about a depth of 30 metres.  It was then slowly raised back to the surface.

A trawl tale, I'm sure.

Any krill trapped in the net would be funnelled into the cod end - a cylinder of hard plastic at the tip of the net that prevents the animals being crushed.

This cod end well, or it cod end badly...

After each trawl the cod end was disengaged from the net and taken into the Wet Lab, where Tasha emptied it into a holding tank.

An air of expectancy pervades Team Krill

Tasha was hoping to collect up to 30 000 individuals, but the krill gods were not playing the game on this occasion.  Each trawl was bringing in some krill, but only in very small numbers.  Between 3am and 11am there were 8 trawls conducted, but with minimal success.  An estimated 2000 to 2500 animals were collected, which is a start, but Tasha is hopeful that she will get the opportunity to conduct further trawling after we leave Mawson.

The krill she did collect were moved from the holding tank to the krill aquarium on board, and here is Tasha examining some of today's catch.

What do we have here, then?

As for the day's catch - here some of them are, happily swimming around in the aquarium...

Happy, happy, happy krill

Evidently some of these krill are well acquainted with Weddell seals (!), because they seem to be quite adept at staying out of focus.

Weddell Krill

At least that's my story, and I'm sticking to it.

So thank you very much for letting me get involved, Tasha!


Aaaand...

While I was in the area,  Cath King (remember Post the Twenty-Fifth?) was kind enough to show me some of the fruits of Ecotoxicology team's labours at Davis, which were being kept in the aquarium next door to the krill.

In this first one we have some more Sterechinus neumayeri urchins which had been collected, just sitting around and being spiny.

Pronounced ste-ruh-KI-nus.  For your info.

They're always getting up to some shenanigans or other, those Sterechinus.



Near to those are some specimens of the Heart Urchins (Abatus) which are the focus of this part of the ecotoxicology efforts.

Pronouced uh-BAR-tus.  Learning a lot today, entcha?  SCIENCE!

Always on the go, those crazy Abatus!

Swim-Swim expressed great interest in having a closer look, and Cath obliged him by carefully fishing one out for him so he could have a closer look.

Swim-Swim: a student of SCIENCE!

Thank you very much Cath, from Swim-Swim and me both!  Swim-Swim's interest in activities scientific has certainly been piqued.



SCIENCE!  It sleepeth not.