Before every dive we check our equipment. Some have more than others: transect lines, clipboards, cameras, buckets, tripods, containers for collecting water. We all have dive gear to check. Once everything is in order we jump in the water, and after a few dives at Kingman we quickly got into the habit of the next round of checks - for sharks and snappers. How many, and where are they? Do they look agitated or curious? Would we know the difference between an agitated shark and a curious one? The equipment check is to make sure everything works. The animal check is make sure we know our environment -- and that we are not being served as a light snack for a voracious shark. We survived Kingman, and its sharks and snappers with all fingers and toes intact. Most of the sharks were just curious, not being used to human presence, they wanted to know what we were doing in their space. What we never check for before our dives is the microbes. Not consciously.
Just as on land, there are microbes everywhere in the ocean. A single mouthful of sea water contains more microbes than there are people in the United States. We don't check for them because we can't check for them. You can't see, smell, or taste the microbes, but they are omnipresent. The ocean is crystal clear, and yet we are looking past millions and billions of tiny microbes with each anxious glance towards a curious shark. The sea is full of microbes, and each coral, fish, invertebrate, plant, and scuba diver is constantly bathed in them. Almost all of these microbes are mostly harmless. They convert sunlight into energy, they fix nitrogen and carbon dioxide, they break down pollutants; they are good for the environment. However, a few of the microbes have a more nefarious intent. These are the bacteria that cause diseases. Just like people get a variety of diseases from microbes, corals get diseased too. When we get a cut or scrape on our hands, or our heads, we reach for the antibacterial ointment. When we are very sick, the doctor may prescribe antibiotics. When corals get a cut or a scrape on them, there is no antibacterial ointment for them. There is no coral doctor to help them mend. At the moment.
The microbial researchers on the crew are investigating the types and causes of coral disease caused by microbes. We would like to know how the interactions between corals and bacteria affect both the coral and the bacteria. We are trying to find out what types of microbes are present in, on, and around the coral, and how these microbes vary between the same coral from different sites or different corals from the same sites. The questions about how microbes affect the reef structures and communities are as abundant as the microbes themselves. Team microbe, our team colors are blue and black, are also examining the quality of the water at each of the sites we visit. We use the same tests for water quality that are used along the streams, rivers, lakes, oceans, and beaches of our hometowns. Using these tools we can figure out how the water quality affects the corals and the bacteria in the oceans.
The bacteria don't mean to be nasty. Like everything else in the ocean, the bacteria are trying to eat, grow, and divide. Get bigger and stronger. Like everything else in the ocean, there are bugs — both bigger and littler — that are trying to eat the bacteria. When bacteria find a way to evade being eaten by something bigger, that often results in their ability to cause disease if they end up in the right place at the right time. Just like we have little viruses that infect us and give us the flu, bacteria have littler viruses (called phages) that infect them. By comparing the delicate balance between phages, bacteria, and corals maybe we can help favor the corals and reduce the amount of disease. Maybe the coral doctor is on his way.
When we get out from a dive we dry off and reach for the antibacterial ointment. Each of our battle scars, won through dives and adventures, gets treated with a little ointment. We don't check for bacteria before we go in - we know they are there. We treat them when we get out. Microbes are everywhere, we are just trying to minimize their effect on our hectic schedules.
—Rob Edwards
Scripps Line Islands Expedition 05