City of Arabel has a fishing system. There are a number of features to the system, some of which are best learned in game. The fishing system is primarily used to support the City of Arabel crafting system and spell reagent system.
Fishing: To fish your character needs to obtain a fishing rod from an NPC and obtain bait. Then locate one of at least 45 separate fishing spots around the module.
Fishing Spots: Every fishing spot is set up to have several different species of fish, the species are often thematically linked to the location of the fishing spot. ie: trout tend to be in fresh water lakes and streams, pyrimo tend are in ponds found in the Underdark, strange mutated and corrupt fish are found in foul waters or places contaminated by strange magics. Some fishing spots may have unique fish found only in that location and the most useful fishing spots are found in out of the way places (after all, an easy to find fishing spot is often over fished and empty of the most useful varieties of fish).
Length of Fish: The length of your fish is determined by a variety of stats found on characters including your Wisdom, Strength, and Animal Empathy.
Cleaning Fish: While most fish used for crafting are 'processed' in the crafting workstation, you can also clean fish that you do not need for crafting. These fish have a chance of producing unique rewards when cleaned. The most common reward is minor magical healing from eating the fish. The longer the fish, the better the reward and the higher the chance of obtaining a reward.
Bait: Most bait costs 1 gold coin, but better bait can be found in the module. The better the bait you purchase, the larger the fish you can catch.