Day 19: It's gettin hot in here.......

The swell continues to prevent any ROV deployments, but everyone's spirits are up, particularly after learning that we appeared on the BBC Jubilee Show in our home-made crowns! The science continues, as there is also equipment that we can deploy in these conditions, and there are many on-board experiments taking place with the corals and sponges collected from the seamound.....

Collecting corals
Today's blog is written by Sarah from Heriot-Watt University in Edinburgh, all about warming up corals!

Think about the reaction of the human body when we enter a very cold room? We all know that we will get freezing hands and feet, but we also breathe faster to compensate for the loss of energy. This is because our bodies are trying to heat up and perform their usual processes under freezing conditions. Now interestingly, the same happens with corals, but in response to warmer temperatures!

We are out in the middle of the North Atlantic Ocean, and we share this spot with deep-sea corals. The corals live 600-800 m below us and are amazing in their structure and diversity, as we see most days on the High-Def screen, pictured by the ROV cameras. We assume that these corals are comfortable in their 9°C, cold environment; we can see their polyps extended and their tentacles waving in the current. It is thanks to Helen and the CTD array that we know all about the conditions on the reef, from the temperature and salinity to oxygen levels!

Corals of the deep
As we know, global warming is happening on our planet, and the ocean temperature is increasing.  the question that I am trying to answer is: Will the cold-water coral Lophelia pertusa increase their metabolism and ‘breathe’ differently when the oceans warm? Or can they adapt to these warmer conditions? Fingers crossed it is the latter!

Corals in their respiration chambers
In my project, I am comparing how corals respond when the seawater temperature is increased slowly, at a medium rate, and rapidly up to 12°C. This is a relatively large temperature increase for these corals, who would have only experienced small fluctuations of less than 1°C. My corals are living in tanks in the cold-room that we have on board the ship. The room is regulated to 9°C to ensure conditions comparable to the deep sea where we collected them – also means we have to wrap up warm when working in there! I am using heaters in each of the tanks to steadily warm up the tanks and control their level. Every third day, I measure the respiration rate of the corals using an optode system and specially designed chambers. I can then compare any changes in coral metabolism that have occurred, and see if the rate at which we change the temperature affects the corals response.

Research so far on both tropical and cold-water corals has shown they are very sensitive to stress, particularly temperature changes, seen in the mass coral bleaching in the tropics. Even though cold-water corals are out of sight, 600 m below us, we still need to work out how they will respond to future changes in temperature, and protect these amazing creatures!