Botswana Blames Poisonous Algae for Elephant Deaths
The deaths of hundreds of elephants in Botswana earlier this year may have been the result of the animals drinking water containing poisonous blue-green algae. Algae are simple plants with no leaves or stems that grow in or near water.
About 330 elephants in the northwestern Seronga area died from a neurological condition. The cause appeared to be drinking toxic water, said Cyril Taolo. He is acting director of the Department of Wildlife and National Parks. A toxic flowering of "cyanobacterium" was found in seasonal water sources in the area.
Botswana's government announced the finding Monday.
The unexplained deaths stopped after the water sources, or pans, dried up, Taolo told reporters in Botswana's capital of Gaborone.
The Seronga area is close to Botswana's famous Okavango Delta.
No other wildlife species were affected by the toxic water. Even animals like hyenas and vultures that were observed feeding on the elephant bodies showed no signs of illness, Taolo said.
Botswana has the world's largest elephant population. An estimated 130,000 elephants can be found in the country. The animals bring many international tourists to Botswana.
Both male and female elephants of all ages died. The deaths happened mainly near seasonal water pans. The incidents did not spread outside the affected area, Taolo said.
After the mysterious deaths of the elephants, the government carried out extensive tests. The aim was to find out why the animals had died. The test results suggested that the elephants died from cyanobacterium, or blue-green algae, poisoning.
Taolo said neurotoxins from cyanobacteria living in affected water could have affected the brain signals of an animal. This might have caused paralysis and death, mostly related to breathing failure.
However, Taolo could not explain why the toxins did not affect any other animals drinking the affected water. He also said that there was no evidence of human efforts to kill the elephants through poisoning, hunting or other methods.
Talo said the government will immediately put in place a plan to examine seasonal water sources often. It will create methods for measuring and testing for toxins produced by cyanobacteria.
I'm Ashley Thompson.
1.toxin n. 毒素；毒质
Experts have linked this condition to a build-up of toxins in the body.
2.method n. 方法
This is an ineffective method of controlling your dog.
You mustn't fire without my signal.
There is a lot of evidence that stress is partly responsible for disease
5.The aim was to find out why the animals had died.
find out 发现
I need to find out who tried to frame me.
I hope we can find out about it.
6.After the mysterious deaths of the elephants, the government carried out extensive tests.
carried out 实施
Two independent studies have been carried out.
Forensic experts carried out a painstaking search of the debris.
今年年初，博茨瓦纳数百头大象死亡可能是因为饮用了含有有毒蓝藻的水所致 。藻类是一种简单的植物，没有叶子和茎，生长在水中或者水域周边 。
在西北部的塞隆加地区，大约有330头大象死于神经系统疾病 。西里尔·陶洛(Cyril Taolo)表示，死因似乎是饮用了有毒的水 。他是野生动物和国家公园部门的代理主任 。在该地区的季节性水源中发现了有毒的“蓝藻细菌” 。
其他野生物种没有收到有毒水源的影响 。陶洛表示，即使像鬣狗和秃鹫这类被发现以大象尸体为食的动物也没有中毒的迹象 。
博茨瓦纳是全球大象数量最多的国家 。据估计，该国发现了13万头大象 。大象为博茨瓦纳带来了很多的国际游客 。
所有年龄的公象和母象都死了 。大象死亡主要发生在季节性水域附近 。陶洛表示，这些事故没有扩散到受影响的地区以外 。
在大象神秘死亡事件发生后，政府进行了广泛的测试 。目的是找出大象的死因 。测试结果表明，大象死于蓝藻或蓝绿藻中毒 。
陶洛表示，生活在受影响的水中的蓝藻细菌产生的神经毒素可能已经影响了动物的大脑信号 。这可能会导致瘫痪和死亡，主要与呼吸衰竭有关 。
然而，陶洛无法解释为什么毒素没有影响到其他饮用有毒水源的动物 。他还表示，没有证据表明人类试图毒害，猎杀或用其他方式杀害大象 。
陶洛表示，政府将会立即实施计划，经常检测季节性水源 。政府还将设法测量和检测蓝藻细菌产生的毒素 。