WP1 is back in the water for the May campaign and diving in some pretty spectacular underwater forests! Seems like we were just here sampling in March, but a lot of changes have happened to the kelp since then. The plants have grown an entire new blade in the last 2 months! That is 50 to 70 cm of growth in the last 8 weeks. Amazing productivity. We have also added another task to all our stations: measuring how quickly tagged pieces of kelp move out of the forest. We originally thought that freely moving pieces would move quickly away from from these exposed reefs. But, most of the drift is actually retained in the kelp forest or accumulates at the border. Urchins seem to be playing a key ro
Yes! And it ended with 2 long days working through the night... which wore out your trusty blogger. So apologies for the late update. Final days of WP3 cruise were spent collecting samples of benthic macrofauna (animals that are large enough to see) and meiofauna and microfauna (animals too small to see) from our 'kelp' and 'no kelp' areas. We used a grab and a box core, both of which we lowered from the boat on a wire until it hit the seafloor, triggering a release that trapped a known size of soft sediment. On deck we sieved the grab sample and took 1 cm slices of the core sample to look at how the community changes with sediment depth. It can sometimes take 30 minutes to gently break down
Well folks... it is time to bring up the time lapse camera. First step, position the ship over the drop location, lower a transceiver over the side and send an acoustic code down to 400 m to tell the rig to drop weights. Seems simple. Except during the long 15 minutes it takes to return to the surface you start to worry, then look frantically, … then desperately hope you have not lost the most expensive piece of equipment on the project. After some suspense it broke the surface! Step 2, bring it on board. An easy task when it is calm, not so much when the waves and winds are up. But, our crew performed some nifty crane work and got it safely back on ship. Exciting to finally see the images.
A key part of understanding the importance of detached kelp in deep sea habitats is measuring how it influences the community. Half of the ship is hard at work on this question. The trawl crew have been collecting fish, shrimps, and other invertebrates from our study area using beam and otter trawls. Data on the total biomass, age, length and number of species will be used to understand the community composition. Information from gut contents and stable isotopes can help us figure out what they are feeding on. Our goal is to track how energy derived from kelp moves upwards through trophic levels, from tiny detritus feeders to larger fish. These data will be used by the third and fourth work
There was a time when the only gear you needed to answer all the pressing kelp-related questions was a scuba tank, a quadrat, flagging tape, and an unreasonable amount of cable ties. Times are changing and WP3 is definitely upping their equipment game. Our second leg of the cruise began with 4 hours on the dock unpacking and assembling the time lapse camera system! Good thing we had our NIVA expert Medyan to help us get it up and running. Also, while we were unpacking Eva found her wool socks. She had packed them with the Gemini core! Classic deep sea biologist move. Our first task was to deploy the time lapse camera at the deep kelp area to record the community response to a fall of kelp. N
