Past participles as the predictive and the adverbial

For the fish living in the Yellow River, it is often impossible to "rot/tank" for a long time. Instead, it is necessary to constantly adjust itself according to the changes in water flow and surroundings. If they perceive/notice/are aware that they are approaching the sea mouth and the salinity will change dramatically, they need to work hard to "go upstream", otherwise they will die in the sea.

对于生活在黄河当中的鱼来说，很多时候是不能够长期“摆烂”的，而是要根据水流和周围环境的变化不断地调整自己游动的方向。如果察觉到已经逼近入海口，盐度会急剧变化的话，它们就需要奋力的“逆流而上”，不然的话进入海中就难逃一死了。

不能够 unable ; not able 

周围环境 environment ; surroundings

不断地 end-to-end ; steadily 

游动 move about ; go from place to place ; play ; free ; unfixed ; swim

入海口 estuary ; entrance ; mouth

盐度 salinity

急剧变化 change rapidly

奋力 do all one can ; spare no effort 

逆流而上 go against the current ; sail up the stream ; sail down the stream

不然的话 Otherwise ; if not

1. (NAmE) [V] (of a company or a product 公司或产品) 彻底失败；破产；倒闭 to fail completely

The company's shares tanked on Wall Street.这家公司的股票在华尔街彻底崩盘了。

2. (NAmE, sport 体) （尤指故意）输掉（比赛）to lose a game, especially deliberately

[VN] She was accused of tanking the match. 有人指责她故意输掉这场比赛。

[also V]