Sampling cold seep communities

Having located a cold-seep site with its attendant community of organisms, it is important to collect samples from the site. This is done not only to identify the organisms present but also to gain more understanding of how they live in such a hostile environment. Dr Ashley Rowden, of NIWA, explains some of the techniques used in the sampling process.

Transcript

DR ASHLEY ROWDEN
What we now want to do is collect some samples from there. So we then follow up the camera work using grabs and corers and sleds trying to target particular habitats within the seep environment, the soft sediments or the hard substrates, to bring back some of those animals. Because without bringing them back, we won’t actually know what species they are, and that won’t help us address that question of how similar or dissimilar are our seep communities around New Zealand from elsewhere.

So when a sample comes back on board, which could be a core for instance or the contents of a grab which might – if you think of like a couple of buckets worth of mud – once one of those samples comes on board, then there’s a whole lot of people there ready to process it by whatever technique is required. So that can for instance include sieving of that mud to get the animals out from the mud matrix, and then you take those animals and you put them in a preservative fluid to make sure that we can look at them safely when we get back. We’d also take some photographs of those animals when we first recover them because colour can change when you’ve put the animal into the preservative.

So we bring those jars and pots full of the preserved material back to NIWA where people will distribute those animals to various experts around the world for identification. Now in the case of an underexplored environment like chemosynthetic environments, most of the animals that we might find were probably new to science and they won’t have been described before. So it’s actually going to take them quite a long time to work out where that animals sits in relation to similar species to be able to give it a name, which then we can use to finally describe the community.

Acknowledgements:
National Institute of Water and Atmospheric Research (NIWA)
NOAA/NIWA
Dr Kareen Schnabel
Max Quinn