A fieldwork course teaches through touch, smell and even taste

During a week-long intensive course, biology students learn to identify the plants and animals of the archipelago as well as to take samples of water and the benthic fauna on the sea floor. At the same time, they hone the basic skills marine biologists need, such as snorkelling.

The Island Ecology course has been arranged at the Tvärminne Zoological Research Station since the 1990s. Year after year it has been a favourite of first-year biology students.

 “This course binds the students to the experience of being a biologist,” explains Tia-Maria Pietikäinen, who studies biology as a major subject.

The week consists of five intense theme days: plankton, benthic fauna, the coastal zone, shore plants and the fish of the Baltic Sea. Each theme has its own experienced and pedagogically skilled teacher. The teacher teaches the same programme to a different group of students every day, but the location of the day’s experiments depends on the weather and, above all, the wind.

A mini-seminar is organised on the sixth day, during which each group gives a presentation on one of the course themes.

 “This course binds the students to the experience of being a biologist.”

 “We have made the contents of the course more research-focused to correspond with the requirements of a new course that will launch next year. We’ve also added new things to our teaching methods, such as underwater photography as well as visualising observations on a digital map template,” explains Kimmo Karell, director and long-term teacher of the course.

Learning to dive

During the morning, the coastal zone group has familiarised themselves with wetsuits and snorkels and taken a peek into the underwater world along the protected shore. For the afternoon session, teacher Niko Nappu takes his group to the rocky shore of Furuskär, on the windy edge of the outer archipelago. The goal is to study the plants and animals of the coastal zone, both on land and in the sea.

The equipment is swiftly carried to the rocks, and after a moment, the whole group are squatting along the shore, photographing plants.  The teacher leads them along at a leisurely pace, first to study the sweet water rock pool that’s teeming with life, and then to the sea. He explains the kinds of algae and invertebrates that can be found on the sea floor, and ones that he has found in previous years.

 “Amazing, but difficult. It’s great that the visibility is so good, the water is clear and there’s so much to see.”

Only one of the five students in the group has tried diving, but in Thailand.  Niko Nappu explains the basics of diving, such as equalising and diving under the surface.

 “Nobody is forced into the water, and during the morning many claim that they will refuse. But by the afternoon, almost everyone will be diving. Some snorkel on the surface, but quite many will also try diving proper,” Nappu explains.

And this happens with this group of students as well. The entire group squeeze into the wetsuits. The students can’t seem to stop giggling, but working together, everyone gets suited up and into the water. And they stay there for a long time. The sample bags fill with algae and crustaceans.

“Amazing, but difficult. It’s great that the visibility is so good, the water is clear and there’s so much to see,” say the last students to climb ashore.

Finally the snails, crustaceans, algae and small fish are poured into a large white vat, and the identification process begins.

“Water plants decompose quickly, so we identify them here on the island. And identification is more fun on-site anyway,” says the teacher.

The best find of the day is a Furcellaria lumbricalis which was found at four meters. Together with a few other findings, it will be brought to the aquarium of the Research Station so others can see it. The rest of the samples are poured back into the sea.

Sampling seawater and bottom sediment

The groups focusing on plankton and benthic fauna, respectively, get in the speed-boat J.A. Palmén to head to Källvik, a gulf in front of Tammisaari.

The plankton group goes first, as taking samples of the benthic organisms in the bottom muddies the water.

The plankton group practice taking water samples with teacher Sanna Korkonen. Sampling is meticulous work – the first sample must be taken at exactly 15.5. meters. The samples must then be transferred to bottles with pipettes in a rocking boat, with no air bubbles allowed to interfere with the sample.

“This sample is teeming. I see long and short strands.”

At the same time, the students must be careful not to tangle the ropes. The teacher gives practical instructions on work safety on the deck of the boat. During sampling, all necessary equipment must be in their designated places to avoid accidents.

 “Drop the string into a basin, don’t wrap it around your hand,” says Sanna Korkonen.

Samples are taken with a variety of equipment from a variety of depths and each case has its own tricks. The sampling comes with a fair amount of bycatch.

“This sample is teeming. I see long and short strands,” says Matias Järvinen, lifting the brown glass bottle against the sunlight. Matias’ major subject is geography, biology is his minor subject.

Later the samples will be studied in a laboratory to determine their nutrient and oxygen levels.

At the beginning of the course, students are warned that during the benthos day, one gets dirty. A few of the students are wearing rubber boots.

“We will take four samples from the mud at the bottom at each measuring site, today from the deep and shallow zones. We take so many samples to ensure that everyone has something to study at the laboratory and to make our work statistically viable. The purpose of the day is to teach students about both the identification of benthic organisms and the long-term, meticulous work required for scientific research,” says Kimmo Karell.

The samples are taken with an instrument constructed by the teacher. There are some misses. A few times, the instrument scoops up nothing, or hits a hard area of the sea floor and is unable to extract a sample before the boat changes position.

During the afternoon, the benthic samples are sifted and studied with a microscope. This time they have found a Monoporeia affinis, an amphipod that is very sensitive to environmental changes, and a mudworm of the Marenzelleria genus, an invasive species which is now plentiful in the area.

“The most necessary and best thing”

While the plankton group are working, the benthic group enjoys the sunshine at the bow of the boat. Some of them jump in for a swim.

The students all agree that fieldwork enables learning at a completely different level than reading things on a computer or from a book.

 “We get to see the plants and animals in their natural environment, and it’s easier to remember their names. It’s easier to remember when the same organism shows up again and again,” says Noora Rinne, an education student who is studying to become a subject teacher of biology.

The courses on plant and animal identification are in the winter, but the teaching progresses at a rapid place, and details such as the orientation of the spirals in different snail shells can be difficult to take in.

 “During the plant identification day, we drive around Hankoniemi in a car, looking for plants. We can touch them, smell them, sometimes even taste them. During the fish days we take the fish out of the nets, we dissect them, study them, identify them, and at the very end, on Friday night, we smoke them and eat them. These methods make sure students learn," says Rinne.

 “Field courses are the most necessary and best thing,” says Tia-Maria Pietikäinen.

The students’ day does not end with the boats and cars returning to the Research Station at the end of the teaching sessions. After dinner, they must still wash the equipment, such as the wetsuits, and prepare their presentation for the seminar on the last day. Many also use the free time to make short excursions, either by boat or by foot, because they may find an interesting individual to add to their herbaria. The laboratory is also open in the evening. Niko Nappu promises to come help the coastal zone team identify the organisms that remained unclear on the rocks of Furuskär.




More information

Read the blog of the University of Helsinki’s research stations.