Observing plankton under extreme conditions
“For the ocean to remain plentiful, plankton needs help from everyone. We, scientists need explorers and discoverers. Anne Quéméré has long accompanied us in her adventures and expeditions on the world’s oceans. Through her numerous oceanic adventures, Anne transmits her observations of the plankton through a “plankton kit” developed by the Oceanopolis Group of the “Plancton du Monde”, maintained by the Charles Léopold Mayer Foundation. Once the results are received, we relay them through the www.plancton-du-monde.org website to schools and the public, fascinated by this yet generally unknown world.
Marveling at the oceans smallest creatures is recognition of these fragile ecosystems, essential to the ecological balance of all oceans.
Science rhymes with conscience. When we measure the consequences of the plankton balances and what they represent in the study of life’s origins on Earth, on the Oceans capacities to feed the world population or to reduce the speed of climatic change, we better understand why we need adventurers-explorers like Anne who are useful partner to science.”
Pierre Mollo, aquaculture scientist specialized in the study of plankton
Plankton: the world’s lung
The word ‘Plankton” describes all living organisms that either float or are carried by currents in the oceans. The name’s origin is Greek meaning “errant, wandering”. Often misunderstood, plankton is at the base of the food chain in the oceans as well as playing an important part in the reproductive cycle of marine mammals, fish, birds and polar bears. It is divided in two fields: the vegetable plankton known as “phytoplankton” and the animal plankton or “zooplankton”. Simply put, phytoplankton produces by photosynthesis half the oxygen consumed by living beings, absorbs part of the C02 and plays an important role in the climatic mechanism of our planet. The phytoplankton is consumed by the zooplankton and by numerous marine organisms, which in turn are victim to larger predators and so on.
Plankton life in the Arctic Ocean
During the polar night, the growth of plankton algae ceases. As the ice melts, various frozen organisms, relying on a variety of currents, enrich the waterborne nutrients close to the icebergs. When the sun returns, marine life awakens, turning on the food chain. During the summer, micro algae grow in the iceberg as well as under!
Arctic plankton during the summer
A NASA mission has discovered under the Arctic Ice an impressive quantity of phytoplankton growth. Scientists have studied many hypotheses to explain this plankton growth. With the arrival of spring, the melting ice produces a stable, desalinated layer of water in a nutrient enriched base. This generates excellent conditions for the growth of micro-algae: the development and recycling of the remains of certain species, stored in the ice, generate part of the necessary ingredients. The water flowing from the Arctic Ocean into the Greenland Sea contains few zooplankton. In that region, only a mixture of Atlantic Ocean water can introduce herbivorous scavengers, therefore, phytoplankton abounds: at least 4 times more than in open waters. However, since 1950 the quantity has diminished by 40%, mainly due to the climatic changes.
What happens in winter
Very little information exists regarding the distribution, evolution and plankton action on organic matter (especially of CO2) during the Arctic winter. Winter conditions have a definite influence on the biological cycle of numerous plankton species. This results in the build-up of food stocks for the larvae of certain fish species. Some small crustaceans are subjected to hibernation cycles and are carried away by the currents. These animals can only regenerate their species if they reach rich phytoplankton areas, in the spring. Some of the adult species will reproduce while the smaller ones will continue their growth. Other species survive the intense cold and continue their development.
Life on the iceberg
Sometimes the iceberg will develop a brownish appearance and give off a strange odour, due to the diatomic growth under the face of the ice. But, inside the iceberg, life settles down between the ice crystals. Plankton algae and bacteria start their development. Some of these organisms spend their total lifetime in the iceberg, others spend part of their life but they are all adapted to considerable salt base and lighting swings. Some of the algae continue the photosynthesis process regardless of the reduced light the Arctic Winter can offer.
Most organisms originate in the oceans, but some come from nearby rivers. In autumn, they cling to the ice. At the outset, there is little plankton, but in spring, both their development and their consumers explode. The iceberg, which can be quite old, has been through numerous cycles. Bands of microscopic ‘communities” are identified and contribute to determine the dates of the various flowerings.