Tioga

Two project team members bringing the grab 
on board Tioga, hopefully with a good sample!

As a benthic ecologist, I've taken plenty of grab samples in my day. It's pretty much a staple of the field. You lower a grab over the side of a boat, scoop up some sediment, sieve it, and preserve the animals. Every benthic ecologist knows how to collect a good grab sample. I can't even tell you how time I've spent sieving sediment samples in the field. The whole process is second nature by now. 

As you might guess, grab sampling is not second nature for everyone. Recently, I had the opportunity to bring others up to speed when a local consulting company asked me to partner with them. I joined the team on WHOI's boat, R/V Tioga, as the resident expert on benthic ecology. 

It was a fun trip. Two of the consultants deployed and recovered the grab - they didn't need me for that part. But once the sampler was on deck, I had to check it. Ideally, you want a grab that fills the chamber between half-full and all the way full. If the sampler penetrates too deep into the sediment, the chamber will overflow, and you have to try again. On the other hand, if the sampler is too light or the current is too strong or the seafloor is too rocky, you might not get a sample at all. You're looking for that Goldilocks zone. 

After the first few grabs, the team knew my selection criteria, so I moved over to the sieve station. I have strong opinions about sieving technique, mostly from years of training from senior researchers. You never shake a sieve side-to-side. Ever. You're not panning for gold. Side-to-side motion will create friction between the mesh and the delicate animals you're trying to sample, destroying their anatomy. Instead, you use rapid up-and-down motions to suspend the fine sediments and let them wash through the sieve. A few people on the team picked up the sieving technique quickly, so we worked together on the samples for most of the day. 

The final step is preservation. For this particular project, we were required to use formalin - a pretty nasty substance, but an excellent fixative. I made sure we had plenty of latex gloves and the formalin was only opened outdoors (you don't want to breathe the fumes). One of the consultants stepped up to learn, and we came up with a good procedure to stay safe during work at sea. 

I was on Tioga for just two days, but the rest of the team kept sampling for a week and a half without me. Daily sample drops mean that the collection of jars in my lab is growing rapidly. We will have plenty of animals to sort and identify over the winter!