Bioluminescence: It glows!
April 18, 2013 – Morgan Ostendorf
Last night and this morning, I finally witnessed bioluminescence in person for the first time; it was amazing! The first time I saw it was when I was filtering chlorophyll samples. As I folded over the filter, I saw a blue light flash. I wasn’t sure if my eyes were playing tricks on me or if I was actually seeing bioluminescence.
I started the cruise with a list of things that I was hoping to see while we were out at sea, sort of like a wish list. Earlier in the evening, I was talking with Nancy, telling her that since I was able to check off seeing whales from my wish list, the next thing I really wanted to see was bioluminescence. She had told me not to get my hopes up as this isn’t really the time of year to see bioluminescence, especially as far as phytoplankton go. Less than an hour later, I found myself prodding the filter with tweezers, with a bright blue flash occurring every time. I was overwhelmed with excitement and at the same time, I was having a hard time believing what I was seeing.
I spent some time talking to other scientists about bioluminescence. The most common color to see for bioluminescence is blue. Many of these tiny organisms contain the protein luciferin (from the Latin for “light bringer”). When the protein reacts with an enzyme (called luciferase) it creates light. The light emitting organ of the cell is called a photophore and it exists in many ocean creatures, especially deep sea ones. Photophores are often used to attract prey.
Lisa told me that some copepods are bioluminescent. After telling Dean what I saw on the filters, he said if I was to look at the filter in the light, I might be able to see a small copepod on the filter. I also learned that some bacteria are bioluminescent. As far as phytoplankton go, it is the dinoflagellates that produce bioluminescence.
After the excitement from witnessing bioluminescence on the filter, things went back to normal and I started to analyze the chlorophyll samples that I collected the previous night (after filtering the chlorophyll samples, we let them sit in a freezer for 24 hours before analyzing them). After a few minutes had passed, Peter came in and asked if I was able to take a quick break (I had learned earlier that I could actually put the samples in the fridge after I had removed the filters and centrifuged them). I placed the samples in the fridge, put on my float coat and followed him to the aft (back) of the ship. I looked at the water and saw flashes of light in the water. All I could do was stand there in awe and wonder. Peter told me that this was the first time he saw bioluminescence so far on this cruise. I couldn’t believe that after being told that it was unlikely to see bioluminescence on this cruise, I had seen it three different times, all in one night! After an exciting night/morning of unexpected surprises, I am happy to say that I can check seeing bioluminescence off of my wish list for this cruise.