Meredith came to us as an undergraduate student, she wanted to gain some experience working in our lab, and brought with her an infectious enthusiasm. During her time with us she has traveled with us to California, Florida and closer to home in the Chesapeake Bay. She already has one publication to her name and is as we speak busy turning her thesis into a manuscript. Her master’s work was focused on the environmental and physiological influences on productivity of eelgrass through δ13C. You can read her defense abstract at the end of this entry. We are all sorry to see Meredith leave us, but she is moving on the new pastures or should we say meadows. One thing that I realized while going through all the pictures of Meredith that I have taken over the past few years is that even when cold, tired and hungry she was always smiling. Now I just have to find a reason to go to a meeting in San Fransico so we can catch up. Victoria

Meredith measuring the reflectance of exposed seagrass PIC_020820110624__Sea Grass_photog Carly Rose_0020Image9Image25Image8

A reflection of lessons learned (post-thesis defense):

Sometimes these types of things are so much more anti-climactic than you hoped they would be.

I didn’t have a great weight lifted off my shoulders, and I always expected to pass (although I had doubts at one point during the defense!). Don’t get me wrong, I’m ecstatic and feel like I’m on top of the world (at least for now), but in my mind, there were no fireworks shooting off in the distance or dancing in excitement around the room after the results came in from my committee. Of course, there are edits to be made to the thesis, but who doesn’t have those? Right? Oh, and that manuscript I still have to submit…

I would have never gotten to the place I am without so many people around me. Leaving for California in three weeks has left with conflicted emotions. There’s a constant cloud of sadness over my head in the anticipation of leaving my real family, and my school family. All of whom I will miss terribly. However, life is giving me new opportunities for adventure and success, so, I must take them. And what better place than beautiful Northern California, where the hills are so steep that I can’t even ride my bike up them and kelp forests call me to the chilly sea?

I’d like to leave you with 3 lessons I’ve learned over the course of 6 years with the BORG,

  1. Never be scared to ask for help or admit that you were wrong. You can learn a lot from people when you open up to them.
  2. Stay at the lab until 2 am to finish those last minute experiments before that meeting that you secretly regret signing up to give an oral presentation at.
  3. Travel those 5,500 miles to present at a meeting that you’re not even sure if people care about your research because every little bit helps. No matter how expensive it is.

 

So, goodbye BORG and ODU. It’s been real. And wonderful!

 

 

Abstract

Seagrasses’ relatively low capacity to exploit HCO3 as a source of dissolved inorganic carbon (DIC) for photosynthesis forces them to rely extensively on CO2(aq), which is typically present at low concentrations in seawater. As a result, seagrass photosynthesis is generally carbon limited. This study investigated the influence of CO2(aq) transport to RUBISCO, controlled by environmental and physiological mechanisms, on photosynthesis, and the impact on seagrasses stable carbon isotope (δ 13 C) composition. Light saturated photosynthesis (PE) was measured at a variety of flow and DIC regimes to understand carbon uptake at the leaf level, boundary layer conditions, and permeability of the unstirred layer. PE was saturated with respect to increases in flow above ~2.3 cm s-1. The non-linear response of PE to [CO2(aq)] was used to predict the maximum physiological photosynthetic rate (Pm). Stable carbon isotope signature for light-saturated conditions was modeled from the theoretical relationship between PE/Pm and physiological responses to [CO2(aq)] and flow that drive changes in fractionation. Predicted δ13C for flow saturated, ambient [DIC] was ~7‰, well within the range of reported values for seagrasses. Measured δ13C values from the Goodwin Islands were lower than predicted light saturated δ13C. However, when historical epiphyte loading was taken into account, δ13C signatures agreed with published values from similar light-limited environments. The ability to accurately model productivity and δ13C of seagrasses suggests a comprehensive understanding of the influence of light, carbon acquisition, and environmental conditions on photosynthesis.

The flowing seawater system at the aquarium has been providing our tanks with lovely fresh creek water, the only problem is all the algae that comes with it. The algae foul the sides of the tank as well as the seagrass, and combined with all the leaves that have fallen from the surrounding trees this makes for a lot of crud in the tanks. We need to reduce the fouling as much as possible as it will cover the seagrass and prevent light from reaching the leaves. Once we transplant our seagrass in January we will be at the facility several times a week and keeping the tanks clean on a regular basis. Our mission last week was to get the tanks clean and ready to receive seagrass in the new year. We skimmed all the leaves off the surface, then drained each tank and scrubbed the algae off the sides finishing with scooping all the crud off the bottom. We had two trays of seagrass that we placed in a tank last month as a test, they were heavily fouled and we feared that they would be dead, but under all that algae they were alive and growing, so the good news is that seagrass love our tanks.

We also made screens for each tank to prevent leaves falling in and to reduce the light to levels the seagrass would experience in the natural environment. With this done they we are set for transplanting in January.

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It seems somewhat illogical to fly 13 hours on a plane and ride 6 hours on a bus (total trip equaling 27 hours) for a meeting that is only 3.5 days long. However, there was no turning back once we boarded the plane in New York bound for South America. The Coastal Estuarine Research Federation 2012 meeting in Mar del Plata, Argentina was meant to bring the two American continents together, but it also attracted scientists from Europe and Australia – a truly international meeting. It was also a tribute to Scott Nixon, one of the grandfathers to marine ecology, who passed away unexpectedly this year. The small meeting size allowed students and researchers to intermingle over the abundant pastries and drinks provided and tango lessons brought us all dancing together in a small, crowded room. Eating and dancing aside, the CERF 2012 meeting was a huge learning experience for me. With no co-occurring sessions, I was able to listen to a broad range of research topics, from new studies on coastal eutrophication, to the physics of the Plata River, to the fishery rivaries between Chile and Argentina (don’t mess with the Chileans!). More so, I was impressed with the caliber of research presented by the South Americans and their ability to do so much, with much less than most US scientists. My oral presentation was well received, so I now have two meeting presentations under my belt! All in all, it was a great experience and I met several people I plan to stay in touch with throughout my career. I also learned that sometimes it’s worth it to travel 27 hours in the name of science.

Meredith McPherson

Meredith is a masters student with the BORG, she is only a few weeks away from defending her thesis.

Dick and I just spent a very productive week at our favourite conference, Ocean Optics. This is a relatively small meeting compared to AGU or ASLO, there were about 2 hundred attendees and with only one session going on at a time you don’t have to make a decision between several interesting talks. I presented my work on Arctic CDOM in sea ice from the Catlin Ice Camp and Dick presented our work on modeling the light availability for seagrass growth in the Chesapeake Bay. I had some very informative talks with the guys from Satlantic and have made my decision on which light sensors to use on my new Arctic buoy system. This meeting is a great way to catch up with friends and colleagues, many of whom I only get to see at this conference. After all the science talk we spent a fun evening at the conference banquet, Dr Alex Cummingham entertained us with a brief history of Scotland, including pictures of the normally shy wild haggis, and a discussion on the Loch Ness monster. We then spent the rest of the night working off dinner with traditional Scottish country dancing. The conference included two very moving tributes to Andre Morel and Charlie Yentsch giants in the world of Ocean Optics who both passed away this year.

Good news! We now have power and flowing water at the experimental seagrass facility, this is a big step for us as it has taken quite a while to get through the construction phase of this project. Our next task was to set up the data and power cabling to each tank. We have spent the past two weeks pulling cables through hundreds of feet of piping to connect each tank to the mobile lab. Today we finished the cabling and the next step is to start setting up the control boxes which will monitor pH and temperature within each tank. It was a beautiful day at the aquarium, we have a very pretty spot right on the creek. Here are some pictures of us working hard.

We are all very excited to be have been awarded a new grant from NSF Office of Polar Programs! The title of our new project is “Warming and irradiance measurements in the Arctic: Determining the link between solar energy absorption and surface warming through long term observations.” This project will look at the connection between seasonal warming of arctic surface waters and the absorption of solar energy. We will be measuring temperature and light both in the ice and the water column at hourly time intervals using a new buoy system, in addition we will add a fluorometer at 5m depth in the water which will help us identify absorbing compounds such as phytoplankton and coloured dissolved organic material. Our collegues in this work areDr’s Mike Steele and Bonnie Light from the Applied Physics Lab at University of Washington, and Pacific Gyre who will make the buoys for us.

As we get to travel back to the Arctic for this project there is a lot of excitement in the lab, everyone wants to see polar bears. I’ll post more information as we progress with this project, we will be making the data from the buoys available in near real time, and will also develop a lesson plan for teachers. For now I will leave you with a picture from our last trip to the Arctic.

This the view every morning as I exit my sleeping tent.