Harvesting fish in pens

100. If you have used baby fish 8 to 10 centimetres long and have fed them well, they will be ready for harvest in about six to seven months. At this time the fish will weigh 100 to 150 grams each.

101. If you want to harvest only some of your fish you can use a seine net with a large mesh.

102. A seine net with a mesh size of 3 to 3.5 centimetres will catch only the biggest fish and allow the medium and smaller fish to escape.

Seine net

103. To harvest with a seine net you will need several people. Start at the deep end of the pen and pull the seine net slowly toward the shallow end. The drawing below shows you how.

Harvest with seine net

104. If you want to harvest only part of your fish, you can also use a cast net or a lift net.

Cast net

Lift net

105. If you use a cast net or lift net you will catch both big and small fish. Keep the fish that you want and put the others back in the pen.

106. With a cast net or a lift net it is easier to catch the fish while they are eating and they are all together. So, feed them some food first.

Give fish some food

107. If you want to harvest all of the fish you can use a seine net with a fine mesh of less than 1 centimetre.

Seine net

Now if you do not need all of the fish harvest only what you need and leave the rest in the pen. Fish can be left in a pen as long as you continue to feed them.