the giant pantry
LIFE ON THE WADDENS THE EBB AND FLOW BENEATH THE SURFACE
The rich animal life on the wadden presents a lavish buffet for wading birds. At a first glance, the wadden looks barren and sterile with its vast and bare surfaces of sand, but appearances are deceptive. The ebb and flow of life beneath the surface is so immense that it is only surpassed by a few other animal societies. Compared to an average seafloor, the wadden contains ten times as many animals measured by weight, and with a total area of 4,700 km2 it is a giant pantry. The rich animal life is largely due to the tide, that twice every 24 hours brings nutrition-rich waters into the shallow Wadden Sea. Life here is based on the high occurrences of microscopic algae, especially diatoms that are the first link in the food chain. Diatoms are found not only floating in the water, but also on its surface, as well as down in the wadden. The brown color often seen on the wadden is due to these algae. Most of the teeming life is found buried in the wadden’s layers of sand and silt. On the clean sand and in the clean silt, animal life is relatively poor. The largest number of animals is found where the composition of silt is between 2 - 20 percent. Some species, such as the cockle and the blunt gaper are clearly visible if you dig just a little down into the wadden. There can be many thousands of cockles on just one square meter. Most of the animals are very tiny, but they often appear in dizzying numbers. For example,
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there can be more than 100 eelworms on just 1 cubic centimeter of wadden. On the surface of the wadden lives the tiny, but abundantly plentiful spire shell measuring only a few millimeters and therefore easy to miss. However, it you look closely, you will note that it is immensely abundant. On just one square meter there can be more than 120,000 spire shells. Beds of oysters and common mussels create habitats for many other organisms. Bladder wrack, for example, has found a way to gain a foothold in the strong tidal current.
The wadden’s land developers
Another abundant animal is the tiny sandhopper that, in certain places can be found in numbers of 100,000 for every square meter. The sandhopper lives in passages in the seafloor, where it consumes decomposed plant material and bacteria, which it filters from the water or collects from the seafloor. The sandhopper’s digging activity is important for the
Lasse Fast Jensen, Fiskeri- og Søfartsmuseet & Torben Kjærgaard, Vadehavscentret Translation: Nanna Mercer, Sirius Translation
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