15th October: Sponges!

Did you know that some creatures can make their skeletons out of glass?

It never fails to amaze me!  My name is Kate Hendry, and I’m a research scientist at the University of Bristol who specialises in understanding the chemistry of these amazing and diverse organisms.  Diatoms, a type of single-celled algae that grows in sunlit surface waters, make ornate shells out of silica (or opal). Sponges are simple animals that live on the seafloor, and live by filtering particles and taking dissolved nutrients out of seawater. They also make a skeleton out of little “spicules” that can be needle-shaped, star-shaped, hooked and barbed.

All of these organisms need dissolved silicon to grow. I study the chemistry of the opal that sponges and diatoms produce, in order to understand more about how they grow. If we know what processes influence the chemistry of these organisms, we can then use their fossilised skeletons – that we find in deep-sea sediment cores – to figure out more about ocean chemistry in the past and how it relates to carbon cycling, ocean circulation and climatic change.

On this cruise, I have a few roles. Firstly, I’m here – obviously – to collect samples of opal!  I’ll be collecting deep-sea sponges from the seafloor, thanks to the ROV crew, and diatoms from the seawater. I’ll also be able to take samples from the sediment cores for fossilised diatom shells and sponge spicules.

Secondly, as I’ve been to sea a few times before to sample seawater, I’m here to help manage the water collection and archiving. We use large bottles, attached to a frame with various sensors (so we can measure the temperature and saltiness of the water), to collect water from different depths. The water is then brought up to the surface, where it can be measured for its oxygen content, or stored for other tests back in the UK.

Thirdly, I’m always keen to help out with outreach to the public, making podcasts (which can be seen on our Youtube channel!) of videos and interviews, and helping out with the blog. Eventually I’ll also be making a longer edited film, when I’m back on dry land! I hope very much that you enjoy the podcasts and blog, and sign up to our Twitter feed and Facebook page!

Blog written by: Kate Hendry

Posted in Preparing for field work
4 comments on “15th October: Sponges!
  1. scelo says:

    Hi Kate,
    Happy to read your first thoughts at sea and to watch the longer edited version of your film once you’re back to UK. We’ll keep an eye on the blog anyway.
    Good luck to all team!

  2. Anna says:

    Hi Kate and Steph!
    Good luck on your cruise! I will be reading the blog and keep an eye out for the photos on Flickr for some inspiration throughout the wet and windy weeks ahead.
    All the best from Cardiff!

  3. Rob Sherrell says:

    Hi Kate –

    Have a very stimulating cruise! I’ll be in the Pacific starting next Thursday. Hey, can I reach you by email on board? I tried sending an email to Laura, but the away message indicated she would be VERY away.

  4. Sarah says:

    Well, I can’t wait to see pictures of those glassy sponges. Any poets on board? there must be so much inspiration from all those strange images.

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