would any information in your book be useful for someone living in a wetlands?

Brenda the short answer is yes. We can manage holistically, and need to, in all walks of life and all environments. Because of the historical origin in trying to solve the thousands of year old problem of desertification people tend to think holistic management is about livestock. It is not although they are essential to addressing desertification and climate change - where nothing else currently known to mankind can do what is required on the scale and with the frequency required.

Most of our materials do still leave people focussed on livestock and that will be corrected over time. I did once experience a rancher repeating training with me gain a great ah ah moment. We had in the training group a factory owner. He posed a question about two problem in his factory - one trying to determine whether some parts should be manufactured in house or externally contracted out. The second a high labour turn over costing the factory a lot. So we tackled these with him solving his problems using the holistic framework and then had a coffee break. The rancher came up to me and said he was so glad to have been there - finally he got it that this was not about his cattle but about his entire life and business.

For years I lived in the Caribbean daily snorkeling amongst the beautiful coral reefs watching them slowly being destroyed by islanders blaming tourists largely. The only way I knew to end that destruction of coral reefs under water was to have used the holistic framework. I could not persuade authorities.
So yes try to learn more about this if you want to save wetlands or manage wetlands.

Livestock and wetlands

Many people do not think about raising critters and wetlands. I know of example where wild rice was raised and rodents were used to havest it. Trails were laid and places to stash grain provided. The rodents gathered and the rice was replaced with corn and cleaned for use.

In another example ducks were used to remove undesired aquatic life before shrimp were planted. Ducks and geese have also been run in wetlands after harvest.

Wetlands are great for harvesting aquatic life. I know of one person who havests leaches for fish bait. Others collect crayfish and bait fish.

Well managed wetlands can also be good sources of wild aquatic life and plants the have economic value.

It is just with wetlands you have to rethink your ideal of farm critters. You would be surprised at the number of critters that can be farmed in a wetland.
The hard part is working within all the regulations governing wetlands that exists today.