Ecosystems - biodiversity and exotics.

In an ecosystem there is a variety of living beings that live together interdependently. This system can be big (a river), small (a pond), or smaller (bottom of your rainwater barrel).

In the ecosystem there is this dance of a hunter and the hunted. The hunter doesn't want to kill all his prey for he wants food for tomorrow. Nevertheless, if the hunted is without a natural predator it risks inbreed and plague. These dancers both benefit to each others presence in this matter.

Every individual human is one of the participants in many ecosystems around the world. It is us who tremble over others for our needs; like expanding urban area, wearing leather shoes, desire for hot showers and use of non-biodegradable substances.

For the rest of the interview this information is basic understanding. Do you read?

UICN Red List
Jip Louwe Kooijmans - Vogelbescherming
Amsterdam Wildlife - Martin & Merel
Groenblauwe Netwerken - Hiltrud Pötz

* 1. As we continue you might realize that unnatural loss or degradation to any of the species has consequences to the entire ecosystem it lives and socialises within. The everchanging balance of populations (plants, animals, micro-organisms) is responsive to all changes.

* 2. To make this clear I'd like to tell you a story of a little critter all of us most certainly are familiar with. He's known as a 'schaatsenrijder' but Latin people would have called him Gerris Lacustris.

* 3. Also, we have this human-being. Out and about camping in nature as we all should. Now what he forgot to consider was that when he throws the soapy water from cleaning his cups and plates in the lake, the soap makes the water retention curve drop (waterspanning).

* 4. This is when Gerris gets in trouble as he is no longer able to walk on water due to the soap. Now when this human-being repeats this a lot for a longer period of time many Gerris' will find trouble to continue living in this area thus food reserves drop for fish, frogs, dragonflies and what not. So as the heron (reiger) starts thinking about moving to another place, we're talking real loss of biodiversity as a result of our way of living.

* 5. Did you already know that over 614 species have left Dutch territory since the last one hundred+ years? Driven out of habitat by infrastructure, climate change or extinction.

* 6. The gray wolf and European eel ('paling') seem to become near-mythical in the Netherlands. They are critically endangered because of human interaction. Mainly reptiles, mushrooms and butterflies have also started skipping this region as a place-to-be.

* 7. With environmental regulations and under the right circumstances populations of vetblad (Panguicula vulgaris), aalscholver (Phalacrocorax), muurhagedis (Podarcis) and the kerkuil (Tyto alba) seem to be on the rise again.

* 8. Empty trailer ships fill up their decks with exotic waters before they cross the ocean. Traditional ships need to do this because a minimum cargo weight ensures stability on open seas.

* 9. When they fill up, all kinds of eggs, larva, bacteria’s, algae, snails, crabs and snakes get sucked in. When they release the water in our home-seaports the organisms blend into our neighbourhood. Sometimes they fit nicely in our ecosystem, sometimes they tend to dominate because they lack a natural enemy. Because of global warming more and bigger exotics will find comfort in our canals and there's nothing we can do about it once they arrive.

* 10. The bright-green Psittacula (halsbandparkiet) have been intentionally introduced and/or have escaped as pet-birds. Four subspieces inhabit city parks and they reproduce. They've squeezed themselves between the others in order to live. They have been described as a plague as they pushed around some of our more timid native birds. They're assumed to steal nesting places. Natural enemy is the (native) predacious peregrine falcon (slechtvalk). They pluck out some distracted parakeets as the rebalancing ecosystem takes it's claim.