The lobster hatchery I mentioned in my last post is under the umbrella of a much larger company, D.R. Collin & Son, which supplies Scottish fish and shellfish to restaurants across the UK and around the world if I am to believe their website. A short walk out of town, their industrial site in Eyemouth is a rather bleak location, but the larval rearing skills I learned and time spent with Chrissy were well worth it (Chrissy and I started volunteering the same week and have become good friends). The St Abbs station aquarium technician has made Chrissy his assistant for mornings at the hatchery and she has settled into the male-dominated world of factory workers remarkably well, even making out their mighty Scottish accents when I didn't understand a word.
Half a dozen females are kept in separate clear tanks, the ones carrying the most eggs tucked under their tails, while the other twenty or so are kept in two larger basins. The fertilised eggs are stored under the female's abdomen for up to 12 months, changing colour from dark green to black and finally red when the embryo consumes the yolk (a food source rich in lipids) before being released as stage 1 larvae. Every development stage is punctuated by a moult, one a week during the first month of a lobster's life, amounting to the four larval stages depicted above (not my picture and approximately x5 their actual size) and gradually less frequent as the larvae progress into the benthic stages. According to the National Lobster Hatchery, a tiny 0.005% of hatchling lobsters survive the planktonic stages, a percentage hard to fathom when seeing the crates of lobsters pulled from the boats in St Abbs harbour alone. At the station too, I was dismayed to see that only 6 of the 11 one-month-old larvae under my care died inexplicably, and those are survival rates once predation and food scarcity are removed from the equation. Every morning in Eyemouth, the new hatchlings are fished out, acclimated from 15°C to warmer 20°C water in which the development process is biologically sped up and transferred to large hoppers until they are grown enough for release into the wild. The females that are no longer "berried", meaning they are no longer carrying eggs and therefore of no further use in the hatchery, are taken away to be frozen and eventually processed for consumption.
I highly recommend this video, which includes all the rearing techniques that I was involved with at the hatchery, although on a much larger scale, and features some cute footage of larvae:
https://www.youtube.com/watch?v=V2UBdsWR18I
as well as this article if you are interested in more in depth European lobster biology:
https://www.nationallobsterhatchery.co.uk/whats-it-all-about/education/lobster-biology/
After spending a few mornings in Eyemouth, the larval rearing at the St Abbs station seemed rather insignificant in comparison, but I have grown quite attached to them and was naturally overjoyed when I found thirty or so stage ones floating in the lobster tank this week. We relocated the adult lobsters to the mesocosm, some of the females still berried, and I'm curious to know if any of the new larvae will ever make it to adulthood.
Sascha
