Fish Farmer

Shellfish

Orkney Shellfish Hatchery is using a land-based hatchery to grow lobster larvae

- Nicki Holmyard

Over the five years that I conceived, then managed, Seafood Scotland’s award-winning Seafood in Schools project, we reached several hundred thousand children, through interactiv­e workshops and projects. They got to see and handle fish and shellfish, and to taste it. Our aims were to teach them where it came from, how it got to their plate and why eating seafood is good for one’s health.

Every child attending a workshop was asked to fill in a questionna­ire, to enable us to see how much they had learnt. We read every single one, and my all-time favourite quote was from a primary pupil, whose main takeaway was: “Lobsters are badass!”

I am not sure how he gained that impression, but perhaps hearing about its carnivorou­s nature and the power of its claws let their mark!

The European lobster ( Homarus gammarus), also referred to as the clawed lobster, may be badass, but their stocks are vulnerable, and UK-based projects have been working to help restore them over the past few decades.

The National Lobster Hatchery (NLH) in Padstow, which celebrated its 20th anniversar­y in 2020, has run several successful projects to this effect, releasing more than 20,000 juvenile lobsters each year since it was set up.

NLH’s Lobster Grower project developed a sea-based culture system to ongrow juveniles in compartmen­talised lanterns suspended from a longline system. This enabled lobsters to grow to around hand-size with no artificial feed input, before being released back into the sea. The researcher­s reasoned that the ability to release bigger and stronger animals would give the lobsters an even better chance of reaching adulthood.

The UK’s clawed lobster industry is small in comparison with its counterpar­ts in Canada and the United States, but it still contribute­s more than £32 million to the economy every year for a catch of around 5,000 tonnes. This makes it an important source of income for many small-scale fishermen and an important area for research.

Cultivatin­g lobster larvae is a complex process that uses “berried” (egg bearing) females captured from the wild and kept in seawater tanks until they spawn. Each female can carry up to 40,000 eggs and the resulting larvae are moved to conical upwelling rearing tanks and fed on microplank­ton, until they reach their third moult, which takes two to three weeks.

Lobster larvae go through four moult stages, during which they develop vital body parts. At first, they loosely resemble prawns, but after the third moult, they start to take on a recognisab­le lobster shape.

At this stage, juveniles need to be separated into individual rearing compartmen­ts, as their increasing­ly aggressive territoria­l behaviour makes them liable to attack each other.

The industry-standard rearing system is the Aquahive, which comprises cylindrica­l containers with circular trays divided into individual sections. Each unit can house up to 4,000 juveniles and facilitate­s easy feeding with a formulated feed.

Ocean on Land Technology holds the patent for Aquahive. This sister company to the Orkney Shellfish Hatchery (OSH), is part of Cadman Capital Group’s Aquacultur­e Division. The two companies work closely together to supply clawed lobster hatchery solutions for lobster stock enhancemen­t projects, both at the juvenile stage and at larger body sizes. Their services encompass hatchery and farming

equipment, systems, feeds and consultanc­y.

Ocean on Land Technology ‘s most recent innovation is a plug and play hatchery-in-abox, which provides a complete clawed lobster hatchery solution within a 20ft or 40ft shipping container, depending on customer needs. It incorporat­es units for broodstock holding and maturation, and for larval and juvenile clawed lobster developmen­t. All customers need to do is to plug in to the main electrical supply and connect sea water to the filtration systems.

A major benefit is that this system can be placed in sensitive locations where planning consent may be limited for fixed buildings, and it can be easily relocated.

OSH recently announced plans to produce clawed lobsters on land, using the hatchery-ina-box, after taking delivery of its first lobster broodstock. The company operates as a multi-species hatchery and also produces native flat oysters ) and lumpfish.

A range of specialise­d feeds is produced to complement the hatchery shellfish products, along with microalgae that are phototroph­ically grown and highly concentrat­ed. The microalgae can be utilised for culturing oysters and other filter feeding species, or included in custom design feed formulatio­ns.

“We are excited to launch our clawed lobster production project, as we begin to introduce a second species to the hatchery. As well as culturing clawed lobsters, we will continue to refine our techniques and technologi­es in order to produce specialist shellfish in a world-class facility,” Dr Nik Sachlikidi­s, Managing Director of Cadman Capital Group’s Aquacultur­e Division told .

Cadman Capital Group took over the OSH just over three years ago and has invested heavily to rebuild and expand the facilities, installing cutting edge new recirculat­ion systems, remote monitoring and alarm systems, back-up systems and a high grade wet laboratory.

“As a research and developmen­t facility for the wider aquacultur­e market, Orkney Shellfish Hatchery has also made significan­t investment into its biosecurit­y protocols, efficiency measures and the developmen­t of feed solutions to optimise the growth and health of its shellfish,” said Sachlikidi­s.

He explained that OSH is currently working to prove the various systems in the hatchery-in-a-box, and to demonstrat­e that recent changes to the Aquahive will allow the production of larger-size, more robust lobsters for restocking programmes. Feed trials and feed management systems are also being refined.

“It is all a work in progress, but work that is showing successful results. Our oyster programme for example is ready to be scaled up to commercial size in 2021,” he said.

A project is also planned for next year, examining the changing economics of lobster farming. As Sachlikidi­s puts it: “All our work is geared towards the efficient and sustainabl­e practice of cultivatin­g shellfish on land, in order to replenish the UK’s seafood stocks, as well as support the global aquacultur­e industry.”

“It is all a work in progress, but work that is showing successful results”

 ??  ?? Right: The hatchery
Right: The hatchery
 ??  ?? Below: Lobster larva
Below: Lobster larva
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