Another night dive and another success for capturing fluorescence from the ROV! The payload developed for this had stopped working, which we’re currently troubleshooting. As such the dive flashlight was attached to the payload bar and after Paul and Chris had helped to achieve the desired weight distribution and buoyancy, we deployed the ROV in the same place as last time (North Aitutaki). We made three transects with the first starting directly ahead of us (North) where we found there to be a considerable current which the ROV was getting caught in, though we did see small amounts of fluorescence. A second transect started West and was flown out to 40m, where we saw flecks of fluorescence. A third transect started West and was flown out to 50m from the beach, which moved with the current East, zig zagging across the coral. This transect proved to be the best distance as we captured extensive areas of green fluorescence! 
Author: Guy Trimby
Oh holy night, the proteins are brightly shining
Tonight we launched the OpenROV equipped with the payload to detect fluorescence in the ocean. It consists of a blue LED strip (excitation source), a power source and a GoPro with a yellow filter (detection). It was launched from the North of Aitutaki in the Cook Islands where an abundance of life exists, including corals, fish, clams etc. Given that many corals are known to fluoresce, our aim for the first trial was to detect fluorescence emitted from a coral. After only 9 minutes in the water fluorescence was detected! A fantastic green hue was observed coming into the view of the camera ending with the coral being seen to fluoresce at about 60-70cm. We believe the coral in the photo is a member of the Porites genus, though this is difficult to tell. Whilst the fluorescence is dimmer than using a torch, this proves the principle that we can detect fluorescence from an affordable ROV (OpenROV) which people from all over the world can have relatively easy access to. We hope that this method can be used to assess coral health and discover a novel fluorescent protein and proving it works is a massive step forward in this research. Perhaps this is the beginning of a great way for everyone to join in and start to systematically assess coral health.
Furthermore a vivid pink colour was observed (picture not shown) using a blue diving torch and a yellow filter and whilst this can be seen in normal conditions, it is particularly vivid with the torch. This was later identified to be a disease that affects Porites coral. So we should definitely quantify the pink areas as well as the total fluorescence as a proxy for coral health.
A few adjustments need to be made to optimise the performance of the ROV, including tinkering with the weight distribution, ballast and buoyancy of the payload. Given the torch has shown better results at the same distances, we may also try and attach it to the ROV and compare the data. Furthermore we ran into a few problems with the tether getting caught on corals, as such we’re going to use a positively buoyant tether on the next tests to avoid this happening again.
Fluorescence
Having landed in Rarotonga a day earlier than the rest of the team, I took the time to try out my fancy new torch to excite fluorescent proteins. I began taking images during the daytime where it was very difficult to see fluorescence but nonetheless was there. Unfortunately I’m still processing the images so they’re not shown in this post. I then took images of the same coral (and many others) after sunset, which produced some fantastic results of green fluorescence (below).
I met the team from CSUCI on Monday and have spent the last few days getting to know them, familiarising myself with a lot of American words and trying to explain how tea is better than coffee! Not great results for the latter but there’s still time …
Hard work begins soon and I expect some problems to crop up, as they always do. But with help from Paul, Chris and the team I’m under no illusion we’ll be able to overcome them with relative ease. As for now, I look forward to getting to know everyone better and getting some fantastic fluorescence pictures!
Fluorescent proteins and the British contingent
As part of this research trip to the Cook Islands, I’m bringing my payload for the OpenROV which has been designed, developed and tested to excite and detect fluorescent proteins in coral reefs. This work is in partial completion of my masters degree at Plymouth University, UK where my research is being completed at Plymouth Marine Laboratory, UK. As such, I am also bringing the British contingent to this international collaboration!
My interests are within using technology to explore and discover the marine environment. This research venture will explore the fluorescence corals produce using my payload. This will be the first time it has been tested in a real world environment, rather than controlled laboratory experiments which have shown great results so far.
Fluorescent proteins pose one of the best visualisation tools in biology. They can be ‘tagged’ to other cells inside the body, including neurons, cancer cells, fibroblasts and many more to act as reporters for cellular localisation, function, movement etc., which is particularly useful in metastasising cancer and tumour growth. They work by absorbing photons at a given wavelength and re-emitting them at a higher wavelength.
These proteins have a colour palette that spans most of the visible spectrum, with the most useful to biomedicine in the far-red. This is due to the body becoming more transparent in the far-red than lower in the spectrum (blue, green etc.), and therefore increasing the resolution and precision we can see down to, allowing us to examine the body and its functions like never before. Yet the far-red remains the only part of the visible spectrum to have no natural fluorescent protein. Whilst this venture is focused on proof of concept, future projects will develop this further to discover a novel far-red fluorescent protein.
On top of this, we believe we may be able to use coral fluorescence as a proxy to assess the state of coral health. This trip, with materials and expertise from our collaborators at CSUCI (Sean Anderson, Paul Spaur and the research team), will provide an excellent starting point to get the ball rolling for a cheap method of coral health assessments.
I very much look forward to meeting the team in person – in less than a week! Now, back to the lab to battle with more technology …