Sharks this week
AOTANI, Masayasu
***********************
Science in the News - Research Shows How Fishing for Sharks Also Affects Other Sea Animals
Also: a new kind of big cat is found on Borneo island. British researchers call for drug policy reform based on new findings. And American officials order stronger warnings for sleep drugs. Transcript of radio broadcast:
07 May 2007
This is SCIENCE IN THE NEWS in VOA Special English. I'm Barbara Klein.
And I'm Steve Ember. On our program this week, we will tell how fishing for sharks may affect other sea animals. We will also tell about (1) a newly identified large cat and warnings for drugs to treat (2) sleep disorders. And, we will report on a proposed system for measuring harmful substances.
Several recent studies have linked human activities to reduced numbers of sharks in the world's oceans. Scientists now say a sharp decrease in the number of large sharks in the Atlantic Ocean has helped some kinds of fish. They say such fish are now threatening other sea animals.
Canadian and American scientists studied the effects of people fishing for sharks in the Northwest Atlantic over the past thirty-five years. Results of their studies were published in Science magazine.
The scientists say one effect of shark fishing has been an estimated ninety-nine percent decrease in some shark populations. They say the loss of larger sharks has caused a population explosion among fish like skates and rays. Such fish and smaller sharks have increased in number along the east coast of the United States.
Sharks usually eat skates and rays. The scientists say these fish feed on shellfish, which are disappearing from the ocean. They say other sea animals are also being threatened by the area's changing environment.
Demand for shark fins has been rising in Asia. Shark fins are used for medical purposes and also for food. The popularity of shark-fin soup in China has made the demand for these animals greater.
For one of the studies, scientists from Canada examined information from private fishing companies and other research projects. They noted a sharp decrease in eleven kinds of great sharks since the nineteen-eighties.
One of the scientists was Julia Baum of Dalhousie University. She says the World Conservation Union earlier this year listed great hammerhead and scalloped hammerhead sharks as being in danger of disappearing. The group also reported the dusky and sandbar sharks as being threatened.
Other scientists agree that the shark population decrease may be linked to the increase of smaller fish. But they say the decrease in sharks is not the only cause. They debate how much the decrease has affected other fish species. Other theories for these changes include pollution and (5) loss of native waters for some animals. (4’2”)
1. Comprehension and Discussion Questions/Topics (10 minutes)
1. What are they talking about here?
2. Name different types of sleep disorders.
3. Why has the shark population sharply decreased?
4. According to the text, what is one possible way in which MDR-TB develops?
5. Give an example of this. It does not have to be a sea creature.
青谷英語のすべて
「英語勉強力： 成功する超効率学習」
（DHC出版のCDBook）
http://aoitani.net/dhc.html
**********************************
青谷正妥（あおたにまさやす）♂
-----------------------------------------------------------
『下に出ていますが、年20回発行で、一回400字という、非常に
slowなメルマガを始めました。』
幸運の青い谷、京大のゴールデンボーイ： 青谷正妥
http://aoitani.net/
（来ると不幸になるホームページ：但し、虫はいません。）
・英語のカリスマ青谷正妥：TOEFL,TOEIC満点達成
http://aoitani.net/TOEFL_iBT.html
・英語のコンビニ：目からウロコの英語情報（メールマガジンです。）
http://www.mag2.com/m/0000113907.htm
・国際交流等の為のメーリングリスト"Friends"
http://aoitani.net/Friends.html
・「人は不特定多数に名刺を配り続けると有名になれるのか？」
http://www.japantoday.com/jp/newsmaker/2
-----------------------------------------------------------