There are no international standards for eco-tourism. It is up to us to define our criteria for a sustainable tourism industry and then be our own watchdogs. There are some generally accepted practices associated with ecotourism though, such as buying local, training and hiring local people, choosing foods with a regard for the local ecosystem, respecting local lifestyle and cultures, managing waste appropriately, minimizing fuel and water consumption etc. Ecotourism is about understanding lifestyles and cultures - authenticity is important. It's not about performing for tourists or creating something that is not here in order to attract a market that is not really interested in us.
Fishing is something people do here and is interesting to an ecotourist.
A fisher could provide tours of his boat, and other types of fishing boats at the dock He could discuss operations of the boat and processing of fish. If he wanted to add to the experience he could take the tourists out in the boat, maybe let them try some of the equipment, and show them the harbour and town from the water. Later he could show the tourists where the nets are mended, the fish processed, then wrap it up with a fish BBQ on the beach, or a seafood dinner at a local restaurant. Understandably there is a worry about jobs on the Islands. And it would be unrealistic to promise or want tourism to be the only profession in town.