On the Misery and Splendour of Ponds in the Czech Republic
Mojmír Vlašín
Summary: A discussion of Czech ponds should probably begin with the famous and memorable history of pond building which dates back to the 12th century. Famous names such as Štěpánek Netolický or Jakub Krčín of Jelčany should be mentioned. As a zoologist, however, I will start in a different way, with the equally memorable history of a fish without which we cannot imagine pond-building in our country, the history of the carp.
The common carp is probably the first historically domesticated fish and today has a cosmopolitan distribution. It is in the true sense of the word a domesticated animal. Czech fisheries are currently based mainly on pond carp farming (87.7% of the fish caught).
But ponds have other very important functions besides fish production. In addition to their undeniable landscape value, they provide good living conditions for a number of specially protected species of organisms, they break down and retain organic and inorganic pollution, as well as they help with water retention in the landscape and function in complex flood protection solutions.
There is a problem with foresters coming up with ideas on how to adjust the composition of Czech forests to a more diverse composition of species as quickly as possible. The same is true for carp, which account for almost 90% of fish production, and fishermen are already starting to think about how to achieve a more diverse fish stock. Yet carp still form the basis of the economics of any fishery.
The basis of the solution to this problem must lie in a society-wide recognition of the non-productive function of ponds.
Because of carp farming, the water quality in Czech ponds is disastrous. In recent decades, cyanobacteria and algae have become prominent, mainly due to a general excess of nutrients, especially phosphorus.
On the one hand, ponds have a glorious history and importance for the landscape and the hydrological systems. On the other hand, they destroyed aquatic ecosystems, tarnished the water, and disrupted non-productive functions. Finding the ideal approach is not an easy matter, nor is a uniform approach possible for all ponds.