VOA科学技术2024--Scientists Say Bird Flu Is Hurting World’s Seal Population

Scientists Say Bird Flu Is Hurting World’s Seal Population

　　An ongoing¹ bird flu outbreak has killed tens of thousands of seals and sea lions in several parts of the world.

　　Scientists said the virus' spread also has caused economic losses at poultry² farms and is harming wild birds.

　　A worldwide bird flu outbreak began in 2020. It has led to the deaths of millions of domesticated⁴ birds and also hit wildlife populations.

　　Health officials have said they do not currently consider the virus a threat to humans. But experts have warned that the continued spread of bird flu could increase the risks to humans.

　　Researchers said seals and sea lions have been affected⁵ in areas such as the northeastern state of Maine and the South American nation of Chile.

　　The virus has been identified in seals on both the eastern and western coasts of the United States. At least 300 seals have died from bird flu in New England. Somewhat smaller numbers have died in Washington state's Puget Sound.

　　Experts said the situation is also severe in South America, where more than 20,000 sea lions have died in Chile and Peru. In addition, thousands of elephant seals have died in Argentina.

　　The virus can be controlled in domesticated animals, but it can spread quickly among wildlife and ocean mammals. In South America, for example, seals that have never been infected with the virus have suffered huge losses, said Marcela Uhart. She is director of the Latin America program at the Karen C. Drayer Wildlife Health Center at the University of California, Davis.

　　Uhart said, "Once the virus is in wildlife, it spreads like wildfire, as long as there are susceptible⁶ animals and species." She said the movement of animals "spreads the virus to new areas."

　　Scientists are still researching how the seals got infected. But Uhart said it is most likely from contact with infected seabirds. She noted⁷ the death rates have been high in South America since bird flu arrived late in 2022. Birds in Peru and Chile have died from the virus by the hundreds of thousands since then.

　　The worldwide outbreak is continuing, and the virus was even found for the first time in mainland Antarctica in February. Scientists have said bird flu might also have played a part in the deaths of hundreds of endangered Caspian seals in Russia last year.

　　The deaths of seals and sea lions can hurt environments where the sea creatures are near the top of the food chain. Seals help keep the ocean in balance by preventing overpopulation of the fish they feed on.

　　Many of the affected animals – such as South American sea lions and Southern elephant seals – have strong populations. But scientists worry about the possibility the virus could jump to more threatened populations.

　　The World Organisation⁸ for Animal Health is a Paris-based intergovernmental organization that seeks to provide information about diseases spreading among animals. The group said in a statement the current situation "presents an unprecedented⁹ risk of wildlife population collapse¹⁰, creating an ecological¹¹ crisis."

　　Some scientists and environmental activists¹² say there could be a link between the bird flu outbreak and warming oceans connected to climate change.

　　Off northern Chile, warmer sea temperatures reduce the population of smaller fish in the area. This can make sea lions weaker and more likely to catch a disease, said Liesbeth van der Meer. She directs the environmental group Oceana in Chile.

　　Van der Meer said scientists and environmentalists are hopeful that vaccinating¹³ poultry will help lessen¹⁴ disease spread. She noted that health officials have also warned humans to avoid any contact with possibly infected animals in the wild.

　　Words in This Story

　　outbreak – n. a sudden occurrence of disease breaking out

　　poultry – n. birds, as chickens or ducks, that are bred for their meat and eggs

　　domesticate³ – v. to bring animals under human control in order to provide food, power or company

　　susceptible – adj. easily influenced or harmed by something

　　food chain – n. a series of living things in which each group eats organisms from the group lower than itself in the series

　　unprecedented – adj. not having happened before

　　ecological –adj. related to the study of relationships between living things

1 ongoing   

adj.进行中的，前进的

参考例句：

• The problem is ongoing.这个问题尚未解决。
• The issues raised in the report relate directly to Age Concern's ongoing work in this area.报告中提出的问题与“关心老人”组织在这方面正在做的工作有直接的关系。

2 poultry   

n.家禽，禽肉

参考例句：

• There is not much poultry in the shops. 商店里禽肉不太多。
• What do you feed the poultry on? 你们用什么饲料喂养家禽?

3 domesticate   

vt.驯养；使归化，使专注于家务

参考例句：

• Many thousand years ago people learned how to domesticate animals.数千年以前人们就学会了饲养动物。
• If you domesticate this raccoon,it will have trouble living in the wild.如果你驯养这只浣熊，它生活在野外将会有困难。

4 domesticated   

adj.喜欢家庭生活的；（指动物）被驯养了的v.驯化( domesticate的过去式和过去分词 )

参考例句：

• He is thoroughly domesticated and cooks a delicious chicken casserole. 他精于家务，烹制的砂锅炖小鸡非常可口。 来自《简明英汉词典》
• The donkey is a domesticated form of the African wild ass. 驴是非洲野驴的一种已驯化的品种。 来自《简明英汉词典》

5 affected   

adj.不自然的，假装的

参考例句：

• She showed an affected interest in our subject.她假装对我们的课题感到兴趣。
• His manners are affected.他的态度不自然。

6 susceptible   

adj.过敏的，敏感的；易动感情的，易受感动的

参考例句：

• Children are more susceptible than adults.孩子比成人易受感动。
• We are all susceptible to advertising.我们都易受广告的影响。

7 noted   

adj.著名的，知名的

参考例句：

• The local hotel is noted for its good table.当地的那家酒店以餐食精美而著称。
• Jim is noted for arriving late for work.吉姆上班迟到出了名。

8 organisation   

n.组织，安排，团体，有机休

参考例句：

• The method of his organisation work is worth commending.他的组织工作的方法值得称道。
• His application for membership of the organisation was rejected.他想要加入该组织的申请遭到了拒绝。

9 unprecedented   

adj.无前例的，新奇的

参考例句：

• The air crash caused an unprecedented number of deaths.这次空难的死亡人数是空前的。
• A flood of this sort is really unprecedented.这样大的洪水真是十年九不遇。

10 collapse   

vi.累倒；昏倒；倒塌；塌陷

参考例句：

• The country's economy is on the verge of collapse.国家的经济已到了崩溃的边缘。
• The engineer made a complete diagnosis of the bridge's collapse.工程师对桥的倒塌做了一次彻底的调查分析。

11 ecological   

adj.生态的，生态学的

参考例句：

• The region has been declared an ecological disaster zone.这个地区已经宣布为生态灾难区。
• Each animal has its ecological niche.每种动物都有自己的生态位.

12 activists   

n.（政治活动的）积极分子，活动家( activist的名词复数 )

参考例句：

• His research work was attacked by animal rights activists . 他的研究受到了动物权益维护者的抨击。
• Party activists with lower middle class pedigrees are numerous. 党的激进分子中有很多出身于中产阶级下层。 来自《简明英汉词典》

13 vaccinating   

给…接种疫苗( vaccinate的现在分词 )； 注射疫苗，接种疫苗

参考例句：

• At first blush, vaccinating the wolves against rabies seems a simple solution. 乍一看来，为狼群注射防狂犬病疫苗是一种简单的办法。
• Also vaccinating children against misers (measles) has saved many lives. 还有，给儿童进行疫苗接种防止麻疹也挽救了许多生命。

14 lessen   

vt.减少，减轻；缩小

参考例句：

• Regular exercise can help to lessen the pain.经常运动有助于减轻痛感。
• They've made great effort to lessen the noise of planes.他们尽力减小飞机的噪音。