Username: Password:   Mandate   Objectives   Environmental Policy   Oyster   Mussel   Finfish   R&D priorities   R&D Coordinator   R&D funding agencies   Species   Health & Nutrition   Benefits of Eating Finfish   Benefits of Eating Shellfish   Market Forms of Seafood   Grades of Oysters   Buying Fresh Seafood   Basic Cooking Methods   Recipes   Care & Storage of Seafood   Sources & References   Island Finfish Association Finfish Production and Methods Summary Spawning Finfish Picture Gallery Pictures courtesy of: Leon Moyeart; Mike Murray; Greg MacCallum A finfish farmer's production cycle begins when the eggs are collected in the fall of the year from the females. A gentle pressure on the abdomen of the female fish will cause her to release the eggs, a process called stripping. In some cases, air may be gently injected into the abdomen to help force the eggs out. Egg fertilization and rearing The eggs are fertilized using the same techniques – gentle pressure on the sides of the abdomen of the males, which expresses the milt. Typically, fertilized eggs are placed into incubation trays with flowing oxygenated water. However, one Alliance facility keeps its salmon eggs in small silos with oxygenated water flowing up from the bottom (upwellers). The amount of incubation time depends on the species of fish and the rearing temperature. A gentle flow of water through the trays maintains the temperature and oxygen conditions at the right level to ensure healthy fry are produced. Salmon start off as pea-sized orange coloured eggs. Eggs are very delicate until they reach the eyed stage (eyes are visible through the egg). Eggs develop into alevin (2 cm long) or sac fry. During this period the alevins utilize their attached sac for food. Feeding is normally initiated when the sac is almost completely absorbed. Once feeding has begun, they are referred to as fry (5-8 cm long). Growout and market size Depending on the species, a number of different grow-out options may be pursued. Arctic Charr are grown in land-based tank systems. Each of these tanks is capable of holding 5000 fish. When harvested each Charr averages about 1.5 kg (3 lbs) and are 40-50 cm long. Because the Gulf of St. Lawrence becomes frozen in the winter, PEI salmon aquaculture is limited to land-based operations. As a result, Island salmon aquaculturists specialize in the egg to fry market. Rainbow Trout are generally grown in pond based cages. Trout fry are typically reared in circular tanks and may double their weight every 28 days. By the time they are four months old they will have grown into 10-gram fingerlings. They are considered market size once they reach ½ kg (1 ¼ pounds). At one Alliance facility trout are also be stocked into ponds for U-fish operations. Generally 18-22 months after they reach first feeding, trout and charr are ready for harvest. The fish are sold in the market place and local restaurants as either a head on gutted product or a fillet.