Words by Lewis Jefferies
As our fisheries face increasing pressure to supply an ever-growing population, the National Lobster Hatchery works to protect the UK’s most valuable marine species.
Image by Corey Holtedit
Rearing the next generations of Cornish Lobsters through their early stages, the National Lobster Hatchery gives this valuable commercial species a far greater chance of survival in the wild.
The European Lobster (Homarus gammarus) is the UK’s most valuable marine species with many coastal communities relying upon it to make their living. To help support the sustainability of wild stocks The National Lobster Hatchery (NLH) in Padstow was opened in 2000. They rear hatchlings through their smallest stages and – according to their website – increase their chances of survival by up to 1,000 times. It is led by researchers and scientists who collaborate with fishermen, local restaurants and the community to help sustain the local fishery. Stock enhancement initiatives like the NLH complement fisheries management measures to help conserve and sustain exploited commercial species like the European lobster.
Dr Carly Daniels is the Head of Production, Science and Development at the NLH and has been working there since 2004. Her work with lobsters began when volunteering at the hatchery as part of her Marine Biology degree at Plymouth University. She is also leading the hatchery’s newest project, Lobster Grower 2, where new techniques are being developed and tested to rear hatchlings for longer, in a more natural environment out at sea. As we watch the lobster larvae – in their planktonic stage – floating in the Recirculating Aquaculture Systems (RAS) Carly explains how they receive their mother lobsters.
“We receive females from local fishermen when they catch them berried up with eggs. We take them in to the hatchery usually at a later stage in the incubation, when they are ready to hatch their babies into our tanks.”
Lobster life cycle
In the first two-to-four weeks baby lobsters are classed as planktonic, meaning they float around suspended in the water column. They grow through a process called moulting where they shed their shells and take on water to increase in size. The hatchery rears juveniles through their first four stages, where they are kept in Recirculating Aquaculture Systems which mimic conditions in the wild by keeping them floating.
Once they reach their last larval stage they are then transferred to the Aqua-hive® systems to separate individuals and prevent cannibalism. “Each Aqua-hive® can carry up around 4,000 animals, and we have a capacity of 20,000 in total.” says Carly. When their last planktonic moult is complete – at around three months old – they possess the natural instincts they need to burrow and shelter on or in the seabed.
Currently, they release lobsters around Cornwall and the Isles of Scilly using two methods; dive release, where volunteer divers will take a small number and release them on a suitable reef during a dive, and offshore release, where fishermen release larger umbers from their boats, using a specialist lobster floom.
Fishing frenzy
According to the hatchery’s website other lobster populations in Scandinavia and the Mediterranean have totally collapsed due to overfishing and show no signs of recovery. Along with fisheries management measures the hatchery’s work plays a vital role in making sure UK stocks don’t go the same way.
The hatchery are working closely with local fishermen and restaurants and believe that having the whole industry involved is the best way to the common goal that is a sustainable productive fishery.
As an incentive the fishermen are compensated £10 per kilo to hand over berried hens. When an egg-bearing female is landed the fishermen will phone the hatchery who send a technician out to collect it.
Headstanding hens
Chris Weston, a technician at the hatchery, holds out a berried hen to show us the eggs around her pleopods (feathery parts underneath the abdomen). A single female can carry anywhere between 2,000 and 45,000 eggs depending on her size, however only about 1 in 5,000 of these is expected to survive when laid in the wild.
“When the hen is ready, she will do a headstand to release the eggs. They then naturally float to the surface, in the wild this usually happens at night for safety, so predators can’t see the larvae.” Says Carly. In the hatchery they will be collected and transferred to the larval systems to begin their first moult.
“In the brood system where we keep all our hens, we’ve got two cold water pools that are set to lower temperatures than the other tanks. This allows us to extend the natural season and bring the eggs on when we are ready.” This would normally be between March and October but cooling the female slows the development of the eggs. This gives them a larger capacity and ability to hold hens at different stages of incubation.
Images by Lewis Jefferies
Ancient arthropods
Lobsters’ ancestry dates back to the Jurassic period when they shared the planet with dinosaurs. They are believed to live up to 100 years in the wild and the largest European lobster ever landed was in Fowey in 1931. It weighed a staggering 9.3kg and measured 50 inches in length.
They have an unmistakable appearance – dark blue armour with yellow, white and red markings, large powerful claws and long red antennae. However, they may change colour slightly when they moult – around once a year as an adult – but only turn bright red once cooked. The claws differ in shape: usually one is larger and used for crushing prey while the opposing one is usually lighter and used for slicing.
Lobster Grower 2 project
After the hatchery process, at roughly three months old they still remain small. Despite their natural instincts, due to their size, they may still be susceptible to predation. This led to a new project to cultivate animals for longer in protected natural environments – the Lobster Grower 2 project (LG2).
Led by NLH, LG2 has had great success in rearing lobsters for a further year out to sea. The hope is that this will act as a transition step, introducing them to ecological factors that will make them less vulnerable to predators and therefore, have an even greater chance of survival. This will ultimately provide more positive benefits for wild stocks and the fishing sector and could also benefit the marine environment in the process by providing artificial reefs.
At the moment it is difficult for the hatchery to monitor success rates as it is nearly impossible to track one of their lobsters once released – at only an inch in length, physical tagging is not an option. “We have a lot of anecdotal evidence from fishermen in areas where they have done releases and have found animals to be the size you would expect from the length of growth time, and they are not finding as many at this size in other areas,” says Carly. Although this observation is a good indicator, the hatchery also strives to provide further scientific evidence to support release age and post release survival rates. Combined with larger lobsters reared through LG2 on-growing trials this will allow the NLH to improve and quantify their impact on the fishery.
DNA sampling
The NLH take DNA samples from all their hens – one from the pleopods and one from eggs – which means they have DNA that will help them identify their lobsters once released. In conjunction with the University of Exeter the NLH is running a project (ERDF Agri-tech Cornwall funded project) that will develop the genetic techniques to allow them to identify hatchery reared animals about five to seven years after release. “We have been taking samples for around five years now and are almost in a position where we can start to sample the fishery, to see how effective our work is.” Presently most of their work is based on other stock enhancement programs elsewhere but that’s something they are working to change.
The NLH are partnered with a local mussel company – Westcountry Mussels of Fowey (WCMF) – who help to install and maintain the containers out at sea, next to their mussel lines. This reduces the carbon footprint of the project and its existence creates an artificial reef which helps the natural settlement of a diverse array of species and provides feed for the lobsters’ development. Other project partners include The University of Exeter, The Centre for Environment, Fisheries Aquaculture Science and Falmouth University.
Image by Katie Sindle
What can you do to help?
A donation scheme set up by the hatchery named ‘Buy one Set one Free’ asks diners at 15 UK restaurants to donate a small amount when enjoying a lobster, which pays for the rearing and releasing of a juvenile to replace the one they’ve just eaten. When you visit a seafood restaurant, look for the sign, and if you buy a lobster, be sure to donate!
Another way to support their work is by becoming a friend of the hatchery via a monthly donation. You can also adopt a lobster (or a whole family!) to fund rearing, from egg collection through to to release.
When buying seafood, look out for certified sustainable species; check out the Marine Conservation Society’s ‘Good Fish Guide’, or conduct research of your own before buying.
The future looks promising
The work of The National Lobster Hatchery continues to grow and become more successful every year. In addition to their newer hatchery in Newlyn harbour – established in 2017 – they hope to extend to more satellite hatcheries and partner with more restaurants. In addition, the techniques and expertise developed during LG2 could see fully cultivated lobsters appearing on UK menus in years to come, which would be a pioneering step in the charity’s work.