Pesticides: a vicious circle.

The indiscriminate use of pesticides sets off a vicious circle: 

• natural predators are destroyed 
• emergence of pests resistant to chemicals 
• without predators, pests increase 
• new, more powerful pesticides are created 
• more predators are destroyed 
• emergence of new, more resistant strains 
• without predators, crop pests increase dramatically 
• a new pesticide is put on the market
• ...and the spiral goes on... 

(Thanks to Lorenzo S. for helping me writing this post)

We're destroying our source of survival. WATER POLLUTION.

As teachers have always told us since the very first years of school, water is essential for life. They taught us the water cycle, that it covers 71% of the earth's surface, that it makes up 65% of our bodies. 
Now, water is becoming increasingly polluted and this is a threat to our health, to the fertility of the soil and to the survival of wildlife. 

Water pollution is the result of human activities. 
The water we daily use in our houses and industries is taken from lakes, rivers and from the underground and, after we have used it (and contaminated it) most of it returns to these locations. 
If this waste water is not treated before it is discharged into waterways, then serious pollution will be the result. 

To prevent water pollution we should remove the pollutants before the water gets back into the environment. 
When the polluted water of the rivers arrive to the sea the nitrates and phosphates create beds of green algae and produce periodic catastrophic loss of marine life. 
In the 60s the Thames was biologically "dead"...nowadays the quality of its water is better. 

This situation is worse in the developing countries, where environmental policies are often almost non-existent and hazardous substances are used in the industrial processes and then poured out into lakes and rivers. 
Lots of people in these countries die because of the contaminated water and many ecosystems have been or are being destroyed. 

(Thanks to Lorenzo S. for helping me writing this post) 

The Iberian lynx.

Lynx pardinus is a species native to the Iberian Peninsula which is in a serious danger of extinction. It is the most threatened feline in the world. 
According to the organization SOS Lynx if it went extinct it would be the first extinction after the one of Smilodon 10000 years ago (indeed it is not a subspecies of the European lynx but a species in its own right).

It is 85-110 cm long and 60-70 cm tall and weighs about 13 kilos. It eats rodents, birds, amphibians and small reptiles; its biggest prey is the hare. It lives in territories of approximatley 10-20 square kilometres. 
Up to the half of the 19th century it was present in almost all the Iberian Peninsula. Nowadays there are only two small zones left in Andalusia, in southern Spain. In 2005 less than 100 specimens were counted, while in 2000 they were more or less 400 and in 1960 they were 4000. 

The only zones in which they live now are Doñana National Park and Andujar Sierra. 
The reasons for the disapperance of the Iberian lynx are the destruction of its habitat, voluntary or accidental poisonings, car accidents, wild dogs, poaching and the lack of preys. 

Luckily, there are good news. In 2005, precisely on the 29th of March, there was the first birth in captivity. In the two zones populated by the lynx, great efforts have been made and this species is on the road to recovery. In 2008 in the Andujar zone the maximum capacity was reached (150 speecimens). 
Now it is estimated that from here each year approximately 20 specimens are taken to be reintroduced in other zones. 

(Thanks to Lorenzo S. for helping me writing this post) 

When the victims become victimizers.

75% of the terrestrial mammal predators (over 15 kilos) are at risk of extinction. This is a serious problem for the environment and the ecosystems as the herbivores and the smaller predators are becoming too numerous. 
The great carnivores are vulnerable as they are few and scattered over large territories; they also have a low reproduction rate and they are often hunted by man, who considers them as a threat. 

In Australia, in the grazing areas the wild dogs dingo have been killed and this provoked an explosion in the number of kangaroos, which damage the grass, and of foxes, that exterminated small marsupials. 

In Alaska, the disappearence of 90% of sea otters, killed by the killer whales, is causing serious problems to the algae prairies because the sea urchins (once hunted by the sea otters) are devastating them. 

In Yellowstone there were too many deers beacuse there were no predators and this problem was solved by the return of wolves. 

Man can try to solve the excess of herbivores with hunting, but he will never be an efficient predator like the natural ones as he often kills young specimens instead of the old and sick ones. 

(Thanks to Lorenzo S. for helping me writing this post)