You have to train to the dog not to do things you don't want him to do.
I have 2 dogs that go fishing with me when the weather is not too wet.
My poodle loves to roll in anything that stinks for sure and haven't been able to train him not to do it.
In the beginning when I had one dog and he was very young it was difficult to keep him close by and it did take a lot of my time on the river. I wasn't catching as many fish, let me tell you.
If I were you, I would train the dog to walk with you off leash first before bringing her to the river. Unless you don't mind catching less fish.
Or bring a long leash so the dog will have some space but can't walk away.
When I got the second dog it was even more difficult to keep them from straying too far.
They were constantly goofing around together further and further away.
But as they grew older they became better at being within an eye shot.
Poodle types are very outgoing and will want to greet everyone which can be a pain sometimes.
Train the recall well and make sure the dog will also come back to whistle. I have a particular way I whistle to my dog and they will hear it far away and come back.
Whistle sound carries far. Also have treats with you.
Good luck,
You're gonna need it