in the 始まり of the 20th century
beginning
人間
human being
繫がる
relate
危険
danger
行動
action
ラッコ
sea otter
苦労
trouble
in the beginning of the 20th 世紀
century
交通事故
traffic accident
decided to help sea otters live 安全に
safely
伐採
logging
危機に
critically
their 人口 decreased rapidly.
population
People were 愕然 about the situation
shocked
danger of extinction due to 原油 spills
oil
絶滅
extinction
分類
categorize
They started to end 乱獲
overhunting
生き残る
survive
住民
citizen
their population decreased 急速に・すばやく
rapidly
シャチ
killer whale
研究
research
生態系
ecosystem
狩り by killer whales
hunting
チーター
cheetah
記事
article
絶滅危惧種 (ぜつめつきぐしゅ)
endangered
土着
native
難題
challenge
人間
human
結果として
as a result