Each port has a Fishery Station or a Whaling Station. The owner of such a Station can engage in fishing or whaling, but is also responsible for processing the catch and selling it on the market. Other gamers can start a fishing or whaling career by purchasing a ship and joining their local Station as an associate. Associates go out to sea, catch and bring their catch to the Station, the Station processes the catch and sells the produce, and then pays the associate their share.
This way, each fisherman or whaler is part of a fleet, and the owner of their Station represents their interests. The owner petitions the Governor or Navy when the fleet needs protection, gathers intelligence on good fishing grounds, provides a place for fleet members to meet and makes sure they sell the product for the best price.
Catching fish or whales is a real specialization. Fish comes in fifteen species, whale in six. The schools migrate the oceans in different patterns across specific regions. Finding the catch is all about keeping track where schools of particular fish or whales are found so their migration pattern can be worked out and the time and place of their location can be predicted. This is knowledge that different fishing fleets will want to keep for themselves. Once the fish are located, a fisherman has to stay on top of a school long enough to fill the nets, while a whaler needs to launch the whaleboats and start the hunt. Wind and current can make this a tricky business, not to speak of the weather, pirates and privateers.