Other inputs and fish density are also carefully limited to avoid compromising water quality or degrading the environment.

其他投入或鱼的密度也要小心严格的限制，以避免破坏水质或者污染环境。

youdao

Instead, fish reared in high-density situations may learn that conspecifics are to be viewed as competitors, rather than as potential sources of adaptive information.

"相反，在高密度情况下饲养的鱼类可能会了解到，同种物种应被视为竞争者，而不是适应性信息的潜在来源。

youdao

The humans of the future, the hybrids we are developing, will not live in a lifeless 4th Density world - spare, bleak, without vegetation, song birds, or fish.

将来的人类，即我们培育的混血人种不会居住在没有生命气息的第四密度的世界里----稀疏，荒凉，没有植被和歌唱的小鸟或者鱼类。

youdao

In recent years, problems have fouled acquaculture's reputation: pollution from waste runoff, high disease and parasite rates due to a high density of fish and the uptake of industrial chemicals harmful to humans have combined to make fish less healthy to eat.

FORBES: Magazine Article

Japanese researchers will now study how the bone density of the Medaka fish has changed over time, helping them understand similar changes that occur in human astronauts.

FORBES: Dragon Returns To Earth With 'Space Fish,' Toothpaste Research