A hands on look at what lives on the Kimberly sea floor

Welcome back! We are now on day 3 since arriving in the study area (Sunday 6 Dec 2015).  See where we are right now.

In my last blog, I showed you how we can see live video footage of creatures and habitat on the sea floor without even getting wet (using the Tow-vid system).

Sometimes, though, scientists need to see creatures first hand in order to understand more about them and where they live. For that reason, on this expedition we are also collecting samples of sea floor creatures for scientists from the Western Australian Museum and elsewhere to study.

To do this, we are using a large metal frame with a mesh bag attached to it called a sled (see below). The RV Solander crew lower the sled carefully into the water using a strong steel cable until it hits the sea floor. The RV Solander then slowly moves forward for 50 to 100 metres as the sled drags along the sea bottom, collecting sand, mud and critters in the mesh bag. Then the crew then slowly pull up the sled using one of the several heavy duty winches mounted from the upper deck.

RV Solander crew carefully raise the sled, secure it on deck, lift the mesh bag over the sorting table, and release the contents

Once the sled is securely anchored to the deck, the crew use the winch to raise the mesh bag above a sorting table and empty the bag.

Sorting sled contents

The next step is to sort everything that came out of the mesh bag into groups based on what kind of animals and plants they are (see below).

WA Museum and CSIRO scientists sort samples into groups on the back deck of the RV Solander

Measurements, photos and preservation

Samples are then weighed, assigned a unique ID number and bar code and then recorded in a computer database (see below). A series of photos is taken of each specimen with its bar code for later use by scientists on land in the laboratory.

WA Museum scientists carefully weigh, catalog and photograph each specimen.

Caption: WA Museum and CSIRO scientists carefully weigh, catalog and photograph each specimen.

Finally, the specimens are then carefully stored in a liquid that keeps them from decaying or are frozen. This keeps them fresh until they can be analysed back on dry land in the lab.

Sample sled hauls

A few examples of the types of creatures we’ve found so far are:

Examples of starfish. Most have 5 arms, but some have 8 or more. An arm can regrow if lost to a predator.
Example of a coral crab.
Nudibranchs (sea slugs) eat sponges and leave a ‘slime trail’ where-ever they go to avoid getting lost
Sea cucumbers are so named because some people consider them a delicacy. Don’t eat the ones shown here though because they are poisonous!
Examples of feather stars. The one on the left is broken and you are seeing the top of it. The one on the right is intact and you are seeing the bottom of it. It has nearly 100 arms!
Examples of creatures collected. Clockwise from top left: sea whips, sponge, sea urchin, soft corals, sponge, sponge.

Now that I’ve given you an idea of the ways we are exploring the Bonaparte Archipelago, the rest of my posts will focus on interesting creatures or habitats we find along the way.

Sea whips look just like their name.

Thanks for reading – see you next time!


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