大象传媒

text and photos by Courtney Flanagan

Two of the scientists worked fast in the brilliant sun and blue sky of 3 AM to carefully pick the fauna out of the mud while two others prepared the lab to receive the samples. Teacher Anna Karin Wallace stayed up with the scientists through the next three collections, all from the Dredge, to help in pulling the fauna from the mud of the sediment. The last Dredging was finished at about 5 AM.

The work of the biologists once the samples are in has to be very fast as the organisms change quickly, as you can imagine, once they leave their dark, highly pressured environment and are in contact with the above surface world. They are first carefully pulled from with tweezers, or rinsed clear, of sediment.

Then they are photographed, and next, depending on the research to be done on each sample back on land, they are put in solutions of ethanol, formaldehyde, or liquid nitrogen. The ethanol preserves the DNA, and since that is currently a primary focus of research, a small part of every specimen is generally always put in the ethanol. Formaldehyde fixes the tissues of the sample, so is used then there is interest in studying the histology of the subject. Finally, liquid nitrogen freezes a specimen immediately at a temperature of -80C.

Of course, careful notes need to be taken of exactly when in time, on what dive, and where on the sea floor and at what depth the samples have been taken.

In addition, a label has to be put into the solution identifying each storage container's specific contents. Labels have to be written in a special pencil which cannot be washed out by the solution. One scientist who was trying to identify some older samples in a museum asked a detective friend to use his skills to decipher labels not written with the correct pencil because they were impossible to read with the naked eye.

Once labelled, the samples are stored in the freezer or refrigerator, depending on their future use. (Periodically, the ethanol has to be changed because the existing seawater in the sponges especially will dilute the ethanol solution otherwise.) And then, finally, the scientists get to rest!

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MICROORGANISMS

The macro organisms are easy to see and admire. Microorganisms however, though not visible to the naked eye, are just as important for study. In fact, it is probably the least known area of biology. Over the last twenty years, knowledge in this field has exploded because technology has become so much more sophisticated, allowing scientists like microbiologist Steffen Jergensen to study the genetic material in these one-celled life forms far more effectively. And there are millions to study. In the sediment we are collecting on this cruise, there are 100 million in one gram at the top levels.

Microorganisms exist everywhere. Currently a Norwegian scientist is running twenty vacuum cleaners 24 hours a day to suck them out of the air! (No, I don't know what kind of vacuum he uses, but he evidently did shop around for the best one!) . Steffen Jergensen photo

The two microorganisms whose cell has no nucleas are bacteria and archea. Archeas have only been recognized since the 1980's. They are particularly interesting for scientists because these particular single cells "work" most like us; their genetic code, for example, is in many ways similar to ours. Initially, the archeas were found only in extreme environments. However now we know that they can be found anywhere. A property of some microorganisms is their ability to oxidize ammonia and form nitrogen, a crucial ingredient for plant life. It is now believed that the archeas are perhaps most active in this regard.

What to this diarist is particularly interesting about microorganisms is the way in which their genetic code can be transferred from one cell organism to another, very different cell organism. Steffen explained with this example: one cell can essentially "spit out" part of its genetic components into the soil, and another cell can pick some of that code up. This process it is believed happens most when the organisms are under stress. Clearly this has all sorts of implications for many aspects of human existence, antibiotic resistance to name one.

Look up our interview with Steffen for continued insights from him on this fascinating area of science.

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