Biography of Maria Vernet

Maria Vernet, from the Scripps Institution, who contributed these thoughts on life at Palmer and on the R/V Polar Duke, won't be in the Antarctic this research season. Her group will instead be headed up by Wendy Kozlowski. Nevertheless, her comments about the researchers' days and nights remain of great interest.

A typical day for the phytoplankton group in the LTER project


At Palmer we have 2 or 3 people. One is always in charge, usually Wendy Kozlowski or Maria Vernet. Two other researchers complete the group. On board the Polar Duke we have twice as many people (6) because we work around the clock. There we keep two 12-hour watches and we have 3 people per watch. The only 2 permanent personnel are Wendy and myself. All the others are hired for the season. Usually they stay between 3 and 4 months. We rotate our personnel so that the ones that come to Palmer Station in October/November stay for the cruise. Most of them leave after the cruise. There are 3 new people that come to the cruise at the beginning of January, and 2 of those stay at Palmer Station until the end of March. Wendy is the only one that comes for the whole season (5 to 6 months every year). Maria Vernet comes either to Palmer Station or for the cruise.

Some years she is off the ice to concentrate on data analysis and publication of results. Her usual time on the ice is about 2 months (she has a young daughter at home, Carolina, 10 years old).


As part of the LTER effort we are in charge of estimating the amount of organic matter that is fixed by phytoplankton, small floating algae that take up inorganic carbon in the water and convert it into organic carbon that can be used as food for other organisms. We measure the amount of production (grams of carbon per square meter of water column per day), and look at how things are different in different areas of the ocean (e.g. coastal versus open ocean waters) and at different times of the year (seasonal cycles). By coming to Antarctica year after year we also measure the interannual variability.

In addition to estimating primary production, we look for the factors that control it. For this purpose we measure nutrients which are needed for growth (e.g. nitrogen, phosphorus, and in particular for diatoms, silicic acid). Light is another important factor controlling phytoplankton growth. Light is measured by the (Ray) Smith group (from UCSB). We measure the molecules inside phytoplankton cells which are responsible for absorbing the light. The light needs to be captured to provide the energy to photosynthesize. These molecules are called pigments and they are colored. Chlorophylls, the main pigments, are green or blue-green. Other pigments are yellow or orange.

Finally, we measure the amount of carbon (and nitrogen) that is contained in all planktonic species. Because we cannot separate plants from animals in the plankton, we collect everything that is in suspension in the water. The amount of carbon is usually related to primary production in the sense that where photosynthesis is higher there are more phytoplankton cells and also more zooplankton cells/organisms that eat them. So particulate carbon and nitrogen are higher in coastal waters than far offshore and higher in surface waters than at depth (e.g. 300 m where there is no light).


At Palmer Station we sample mostly for studying the seasonal variability. We have 2 main stations which are sampled twice a week, on Mondays and Thursdays. These days vary a lot depending on wind, ice and snow conditions. We have to wait for good weather because that is the only time that the Zodiacs can go out. On the days in which we sample we leave after breakfast, around 8 to 9 am, and start sampling the farthest station (St. E). We have a Zodiac with a winch to lower the sampling bottles to the desired depth. Water is sampled with 5 liter bottles called "Niskin bottles". The bottle is attached to the wire and lowered. The depths of sampling are chosen according to light levels in the water column. Upon reaching a station we lower a light sensor (measures visible light only, from 400 to 700 nanometers, called PAR or "Photosynthetically Available Radiation"). We pick the depth corresponding to 95%, 50%, 30%, 12%, 5% and 1% light levels. The water collected is placed on a 4-l jar and is kept in a cooler with ice until we get to station.

At (Palmer) station we
  1. Sample the water for chemical and biological analysis and
  2. Start photosynthetic experiments to estimate primary production.
Sampling for photosynthetic pigments and particulate carbon are done by concentration of material on filter pads by applying suction (or vacuum). Once collected the samples are frozen in liquid nitrogen. Carbons are analyzed in the U.S. Pigments are analyzed at Palmer Station. Nutrients are analyzed directly, without treatment or concentration, at Palmer Station. For primary production we divide the water in 4 100-ml flasks for each depth, add a very small amount of radiocarbon to each bottle and place them in an incubator outside the building. The incubator has 6 light treatments. Plexiglass tubes are covered with screens that decrease the amount of sunlight to imitate the depth at which each sample was taken.

The day after a sampling day is used to terminate the primary production experiment (after 24 hour of incubation), analyzing the samples for pigments, entering the data from the sampling and analysis into a database in a computer, cleaning and organizing samples and data and getting things ready for the next sampling day.

Weather permitting we have a third sampling day per week. Usually Wednesdays. We sample at St. B (off Bonaparte Point) to collect water for other experiments, the same way we do on Mondays and Thursdays. Once the water is back at the station we set up specific experiments to estimate growth of phytoplankton or to estimate the effect of ultraviolet radiation on primary production.

Saturdays are spent cleaning and "doing data".

Sundays are off.

(Karen Baker is getting a MS ready for the "Antarctic Journal" where all this sampling is summarized. You might want to get a copy from her when it is ready, probably in 2 or 3 weeks.)

R/V Polar Duke

On the Polar Duke we do similar work as in Palmer Station but about 5 times more intense. The big difference is that we work 24 hours a day, 7 days a week. We sample an average of 4 stations every day, sometimes 5 stations. At each station we start a primary production experiment and sample for all the other variables as well. At the same time we finish the 24-hour experiments from the day before and analyze the pigments collected earlier. Nutrients are analyzed fresh after every station. In between stations and analyses we do the data entry and processing. If time is not enough, the data processing gets delayed.

We usually catch up on the backlog on bad weather days where sampling is not possible or reduced, in days where something else is going on (i.e. only bird sampling), etc.

The routine on the ship is broken up with some parties and visits to nearby stations: Palmer, Faraday, Rothera. Sometimes we go to Hugo Island (ed. note: which some call "Santa Claus Island": see Deane Rink's Journals) to fix or do maintenance on the weather systems.

While at Palmer we have a working day that is more similar to work in the States, work on the ship is very different. At the station we wake up for breakfast and work around mealtime although sometimes we miss lunch (if for example we got delayed in the sampling). But we are usually back for dinner. There is a quota of daily exercise, either walking up the glacier or going to the gym. Sometimes there is skiing, early in the season. At night there are other social activities like watching movies, playing ping-pong, getting together with friends or developing pictures. The bar is open also in the evenings until 10pm. On weekends it is possible to visit nearby penguin rookeries, with permission. On the ship there are no activities besides a very small gym and sauna. There are movies but usually there is not much time (or energy) left to watch them. So we find entertainment while we work, like listening to music or having people not on watch visit (and sometimes help) in the lab. The highlights of the cruise is the camaraderie that develops between people by working very hard towards a common goal. There is also beautiful scenery, particularly when we sample in the channels. And every day is different because we never sample in the same place.

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