A Few Days In Portland: Phytoplankton, Sea Ice and Cake!

Early morning photograph of Portland, Maine

Early morning photograph of Portland, Maine

As I talked about in my last blog, this week I’m attending the Ocean Optics XXII Conference in Portland, Maine in the USA. I arrived last Thursday and spent the weekend at a two day pre-conference meeting entitled ‘Phytoplankton Composition From Space’; where we discussed techniques for mapping phytoplankton – the microscopic plants in the ocean.

The smallest phytoplankton taxa (group) are the single celled cyanobacteria known as blue-green algae, they are an ancient life form with a fossil remains of over 3.5 billion years old. They can be mapped from space using ocean colour satellites which measure a signal based on the scattering and absorption of light within the ocean. This enables Earth observation to map the total biomass, via the concentration of the main pigment that’s normally Chlorophyll, and also get a glimpse into which taxa are present.

Understanding the concentration, and diversity, of phytoplankton is valuable as they play a key role in climate processes by absorbing the greenhouse gas carbon dioxide. In addition, they are the very essence of the bottom of the food chain, as they are eaten by zooplankton, who in turn are eaten by small fish and so on. Therefore, significant changes in the concentration or diversity of phytoplankton may have ripple effects through the aquatic food chain. The film Ocean Drifters provides an overview of the role of plankton in the ocean.

The conference itself began on Monday and we’ve had a number of interesting and varied presentations, but I’ve particularly enjoyed two plenary sessions. The first was by Don Perovich, of the Thayer School of Engineering looking at the impact of sunlight on sea ice in the artic. The brightness of sea ice determines the amount of light reflected back to space. If the ice is older, and hence snow covered, then it’s bright white whilst ice that’s melting is much darker due to the pools of water and so absorbs more sunlight. Therefore, there is a positive link between melting ice causing ice to melt quicker. In the Artic, sea ice reaches a minimum in September and causes an increase in melting. There is a scientific analysis on Arctic sea ice conditions here.

The second plenary was given by Johnathan Hair from NASA Langley Research Centre, presenting a paper co-authored with his colleague Yongziang Hu and Michael Behrenfeld from Oregon State University. It focussed on using lasers for mapping vertical profiles throughout the water column from space and applications for inland waters, and how this might be used in global ocean plankton research. Regular readers of the blog will know this is topic is something that particularly interests me, and I have previously written about the subject.

Tuesday morning was eventful, as the conference venue was evacuated just as the first session was starting, due to a strong smell of gas. I took the unexpected networking opportunity, and to catch up with one of my former colleagues over a coffee. Thankfully, we were let back into the venue a couple of hours later, and everything went ahead with a bit of rescheduling. My plenary session on Crowdfunding Ocean Optics went ahead in the afternoon, and seemed to generate a good level of interest. I had lot of questions within the session, and a number of people sought me out during the rest of the day to discuss the idea and the project.

I’ve really enjoyed my time in Portland, and have found a fantastic coffee shop and bakery – Bam Bam Bakery on Commercial Street – which I highly recommend! I’m looking forward to the rest of the week.

Citizen Science, Secchi Disks & Ocean Optics

Tomorrow I’m off to the Ocean Optics conference, which has taken place every two years since 1965 and brings together specialists united by light in the ocean; this year the conference has topics as varied as environmental management, fluorescence, remote sensing, phytoplankton, sediments and underwater imaging.

Secchi disk measurements, as of mid October 2014

Secchi disk measurements, as of mid October 2014

I first came to Ocean Optics in 2006, when it was held in Montreal, Canada. I enjoyed it so much I’ve attend every one since, which have been in Castelvecchio (Italy), Anchorage (USA) and Glasgow (Scotland), and this time we are in Portland, in Maine USA. One of the things I really like it is, unlike large conferences, there are no parallel sessions, and so I don’t have to make any difficult decisions on which speakers I can, and those I can’t, see. Conferences can reinforce the silo approach, with the Ocean Colour group meeting in one room and the land remote sensors meeting in another. I think the Ocean Optics format promotes a more collaborative atmosphere, where you see a more diverse range of presentations and people. The collaborative approach to research and innovation is at the centre of my philosophy of working, and so Pixalytics is also one of the conference sponsors.

Next Tuesday, I’m giving a keynote presentation on Crowdsourcing Ocean Optics. My presentation will bring together the topics of Citizen Science, collaborative research that includes members of the public in any one of a variety of way, and Earth observation (EO) data acquired via ocean colour satellites; one example of this is the Secchi Disk project.

A Secchi disk, originally created in 1865 by Father Pietro Angelo Secchi – who was the
Pope’s astronomer, is a flat white disk 30cm in diameter, attached to a tape measure or a rope and also weighted from below. The Secchi Disk is lowered vertically into the water from the side of a boat, and the point at which the disk just disappears from sight is recorded. This depth measures the turbidity of the water, which is influenced by the amount of phytoplankton in the water column.

The Secchi Disk project developed smartphone Apps to allow participants to use a homemade Secchi disk and their smartphone / tablet to record and upload depth data alongside positional information. Through everyone uploading their measurements we are building up a global map of Secchi depths.

The project is a collaboration between Dr Richard Kirby who leads the project and publicity, with Dr Nicholas Outram and Dr Nigel Barlow (Plymouth University) as the App developers, and myself for the online database and EO linkages. The Apps were released at the end of February 2013, and since then 481 Secchi disk measurements have been collected globally; see the figure at the top that shows the global distribution of the uploaded data with the coloured Secchi disks indicating the values recorded.

The Secchi Disk project data is being compared to ocean colour satellite measurements as a cross-validation exercise and, in the longer term, to contribute to our understanding of phytoplankton dynamics. Why don’t you become part of the growing citizen science movement, go on take a measurement and upload it!