This season has been a success according to Paul! We set out to work on two programs – recovering experiments and getting a broader quantitative perspective of various habitats - and both have been a success.
This is Paul’s favorite anemone that he has named Miss Piggy because she ate all those scallops. Paul’s favorite animal is the sea star Perknaster because it can do so many things and the magnificent Volcano Sponge because they release eggs whether fertilized or not and if the conditions are right they grow huge really quickly.
On the one hand we returned to specific spots on the seafloor to photograph my old transects and recover my old experiments - floaters, cages and other settling surfaces. With the help of SCINI and the SCUBA divers, we took pictures and videos of about 50 floaters, cages, and settling plates and recovered about 10 experiments. Now we can analyze all of this data to document changes over time. I can already say that from the late sixties to the late eighties, few critters settled and they grew slowly. Then for the next twenty years, from the nineties to now, things grew fast and settled densely. Why? I suspect oceanographic forces are at work but I don’t know why things changed in this way. I need you my dear reader to continue these studies to help us understand this better. What will happen in the next twenty years? Who will research this? Few students are being trained to do this, so all of us and especially these wonderful unusual animals hope that some of you will become interested in being the type of marine biologist that actually goes outdoors and studies nature rather than models and homogenates!
Who will be the next person to see my cages? What will you see?
SCINI is an extremely interesting and effective tool that helped us with our second program - expanding our quantitative understanding of habitats. When I was here in the sixties, seventies, and eighties, it took me days to dynamite or chainsaw holes which then gave me access to the seafloor. I was then able to dive in various locations but I only had about 20 minutes on bottom per dive. Now with about 107 hours of dive time with SCINI, over the course of 37 missions, to depths of 130, 160, 180 and even 320 feet, I was able to see, photograph, and document much, much more.
David, DJ, and Paul with SCINI. SCINI took 9,000,000 images for us!
With all of these dives, we investigated different types of habitats, various spots in each habitat, and different depths in the habitats. For one, we looked at the two different sides of McMurdo Sound. Here in front of our station we have a current that brings nutrients and light for this rich, diverse collection of sponges, tunicates, sea stars, anemones, and all sorts of other critters. Across the west side of the sound at New Harbor and Salmon Bay we observed mostly brittle stars and clams due to the nutrient-poor current. At Salmon Bay, we saw the most impoverished, least productive community. The current that brings water to the west side was under the permanent ice and so is void of food for the critters. With these data, we understand these communities and the effect of nutrients much better.
The nutrient-poor side of McMurdo Sound. What can live here?
Within these two east and west side regions there are also north-south gradients. Along a 10 mile stretch of the Ross Island east side coast, we drilled numerous holes between Cape Armitage and Cape Evans. With SCINI we were able to dive at six of them, exploring a circle with a diameter of up to 600 feet at each hole. At one place called Cinder Cones we saw hundreds of Odontaster validus, the small red starfish, living in the gravel, while at another spot called Cape Evans we saw a seaweed community. In front of McMurdo Station we observed the sponge specula mat. These different communities show us what happens with varying amounts of light due to ice thickness and, more importantly, snow cover. When the ice is thick with a thick blanket of snow on top we see more sponges and bryozoans that grow slowly, while an area illuminated by light due to less snow cover or maybe thinner ice, we see more productivity by high densities of herbivores such as sea urchins and Odontaster validus (sea stars).
Julie with a rich community of critters under a thin layer of ice.
Finally each site has ecological gradients across depth gradients. The different depths showed us different communities. At shallower depths we found more productivity but also more disturbance by anchor ice so the animals that live there, anemones, bush sponges, soft coral and hydroids, grow fast but die sooner because of the anchor ice. As we go deeper we move into long lived sponges, and finally as we get deeper we move into a habitat that has less productivity and fewer sponges, with the space being replaced with very slow growing bryozoans that need much less food. My previous studies had led me to believe that this would be the case, but now we have documentation of it. This documentation helps us understand this part of our world much better. Getting the data now not only allowed me to offer my 50 year perspective of the area, but it allows us to document what we see in this area before it too gets further affected by the changes that our modern lives are having on all parts of the world. Our world is changing and it is important that we remember the past and train students like you to study the future. Thank you very much for your interest dear Reader!
Paul Dayton
What did Paul just do? Look at Stacy’s face. Do you think Paul is disgusting? So do his friends.
