• Indhold

Phytoplankton – seen from space

Written by Peter Viskum Jørgensen and Niels Kristian Højerslev

The oceans cover around 70 % of the Earth’s surface, and it is home for a great fraction of life on Earth – from the biggest animals, the whales - to the smallest forms of life in the form of bacteria and virus.

The phytoplankton makes up the first part of the marine food chain. They are very small plants (in the order of tenths of a millimetre) which are eaten by zoo-plankton (animal plankton), fish or even whales. The latter can filter enormous amounts seawater each day to get their daily supply of plankton food. The figure opposite shows some of these algae seen in a microscope.

Phytoplankton

The oceans are therefore an important part of the world’s nature and resource basis. Therefore, everybody has an interest in keeping a healthy marine environment. In order to ensure this, we monitor the oceans, both locally, nationally and in a few cases also internationally.

Both the frequency observations and method of observation varies from area to area and from country to country. Traditionally ships have been used to collect water samples at sea a few times per year, but today methods also encompasses measurements from buoy’s, ferry’s, aircrafts and satellites that can be taken more or less continuously. In some cases all around the clock, 365 days a year, in others covering large areas once every day as what is the case with some satellites.

Recently, biologists have also started working with advanced mathematical models to better understand the variations in the environmental parameters. This can also serve as a supplementary tool in periods with little or no observations from other sources.

Algae as seen in the microscope. Click to enlarge