A group of highly endangered Yangtze finless porpoises (江豚) was recently seen in the Yangtze River in the area of Wuhan, Hubei province, which may be a result of China’s 10-year ban on fishing in the river at the beginning of the year 2020, less interference (干扰) from human ________(activity) or an increase in food availability. （所给词的适当形式填空）