[ams6110]

Even an entire human lifetime is an eyeblink in the ebb and flow of the ocean environment. No matter what experience a person has, his own observations mean nothing, or rather, are insufficient to assign any causality other than natural variability. Most of the species that have ever lived in the oceans (or anywhere else on the planet) are now extinct, and this happened long before humans had any influence.

[sousousou]

I agree with you, but this statement has no ethical weight. We still get to choose whether to do something, and if something, what.

[Shinkei]

"his own observations mean nothing, or rather, are insufficient to assign any causality other than natural variability."

This would be an accurate statement, but the last hundred years have been particularly relevant as human activities have exponentially soared. You are hiding your head in the dirt if you think that our level of influence is insignificant over the course of a lifetime.