This website has been down for a number of months. It had been hacked and blocked, but that is all fixed now. Meanwhile much has changed around me. I will resume fieldwork in South-America with colleagues from Chile, Argentina and Uruguay. A first model to predict killifish population dynamics is being debugged. The fish are done with overwintering. See you all soon!


tanks (2017)Inside the wooden house, there is still fry approaching maturity. They were born a few weeks ago and have been fed once with Artemia, after that with pond invertebrates. Now they will need to overwinter at relatively small sizes and without heating. Critical to make this work seems to be using tanks with a large surface and low depth and to have sufficient thermal mass in the house. When I see a plastic box in a shop, I get the feeling I can predict how many I can raise in there to maturity, just by looking at the surface area. Maybe it’s time now to start experiments on density-dependent growth and survival in my fish.

In the house I also store orchids (Zygopetalum), palm trees (Archontophoenix) and citrus (Yuzu, finger lime) during winter and cuttings of Physalis Peruvian groundcherry.

Bad luck

Hedgehog (2017)This guy has made a wrong decision or has just been unlucky. I spotted him while fishing Chaoborus. That isn’t very easy at the moment, due to the layer of Asolla cristata. I try to remove it every week and plan to use it as a soil fertilizer.

1000 islands

Filter plant islandTo keep tanks clean(er), I decided to use plants that grow well and root well in water as filters. Here on the photograph three different plants on small floating islands in my fish basins, situated in an unheated greenhouse. They all grow through winter. Leftmost: Vietnamese coriander (Persicaria odorata), middle: Japanese parsley (Oenanthe javanica), right: watercress (Nasturtium officinale). What’s really great is that the plants need to be kept growing to make them take up nutrients. What helps well for that is harvesting them, and all three are edible. Aquaponics in its simplest form.

What’s eating my banana

Roseringedparakeet2015Funny surprise a few days ago. Not a recent summer storm, but an Asian invader seems responsible for a lot of damage to one of my Musja basjoo lining the allotment. Less funny: the small canal aside is full of sticklebacks at this moment (already before the storm), eating the food for my killies away. When I fill my tanks, I need to be careful to keep them out.