Our lobsters go through distinct growing cycle stages whilst with us and as they are marine invertebrates moult their exoskeleton as they grow and become bigger. Each area of the Hatchery is dedicated to a part of the process of producing a juvenile lobster from an egg for release back into the Firth of Forth as we hatch, rear and release.
Hatch-Broodstock Lobsters in Hen Room
Our female lobsters with eggs (called berried hens) are kept in individual tanks until the eggs hatch. It can take many months for the black eggs the female carries to hatch in the wild, with sea temperature being the main factor. A hatchery can speed up or slow down this hatching by heating or cooling the water to manage the supply of larvae. As we run seasonally our hens are supplied to us by local fishermen when their eggs have naturally ripened, typically between May and October, ensuring we keep things as close to nature as possible.
Eggs close to hatching change to a brown/red colour from a darker black. The female lobster will help the larvae to hatch by pointing and “fanning” her tail which helps shake off the larvae that are ready. This is normally done at dawn and dusk over a few days until all of the eggs have hatched. We have tanks designed to receive the newly hatched larvae automatically as the water flows directly from the individual female lobster containers.
Rear-Larval Lobsters in Production Container
The hatched larvae are collected each morning and transferred and counted into the larval pods in our production container. The tiny lobster larvae are kept in a constantly moving gentle flow of water and fed plankton and a specially formulated diet as they grow. The movement of the water helps keeps the larvae suspended and reduces the risk of the larvae settling out on the bottom and fighting. In the wild the larvae would be floating in the top few feet of the ocean where they hatched.
As lobsters grow they shed their skin progressing through each stage until the fourth moult, where they are identifiable as a miniature lobster. After their third moult they are known as juveniles, are separated into individual cells and transferred to our aquahive tanks.
Rear-Juvenile lobsters in aquahive
The juvenile lobsters now begin their benthic lifestyle (living on the sea floor) and can be very aggressive towards each other so in the hatchery they are kept in individual cells within the aquahive. They grow rapidly and will moult every few days until they are a size suitable for release.
Release-Juveniles back to sea
The timing for release is dependent upon tides, staffing, volunteers and weather as well as the temperature within the hatchery, which is controlled by the hatchery technician, but it is most likely that juvenile lobsters will be about 8 weeks old when they are released into the sea. This is done straight from their individual cells, after they have been acclimatised to the sea temperature.