The purpose of the lines is to:
And every fair from fair sometime declines,By chance,or nature’s changing course untrimm’d

The correct answer to this open question is the following.

I am going to pick Kara, the main character of the story "The White Dolphin," to write my speech keeping in mind the character's point of view about 'saving the dolphins and marine life.

Dear people of Cornwall.

Mother nature provides us with everything we need, why is the purpose of damaging the mother nature of one of its creatures? Who gets the benefit of doing so?

It is unbelievable that we hurt nature daily and nobody cares. Do we need a time of scarcity to learn a lesson? Do we need a natural event to make us think? What about a hurricane or an earthquake? Only in those moments, we remind ourselves of taking care of nature because it is more powerful than humans.

No, we better not live a situation like that because it causes so much destruction and pain. But that is precisely what we do to the earth and its creatures when we do not pay attention to our actions when we forget to take care of the planet.

If we make our living from the sea, we need to take care of it and the sea life.

Please, I kindly invite you to reflect on these issues and change your perspective. If we still hurting mother earth, in the end, we as humans must suffer the consequences.

Please dear people form Cornwall, let's change our attitudes and make better decisions.

With love, Kara.