Loch Long Salmon

WelcomeAboutThe Beinn Reithe ProposalBenefits


Loch Long Salmon is a new, low-impact salmon farmer focussed on environmental stewardship and animal welfare, which plans to open its first farm in 2023.

We will be the first in Scotland to use semi-closed systems, which eliminate sea lice, capture, remove and reuse almost all solid waste and eliminate the need to control other marine species such as seals.

We want to change salmon farming in Scotland for good.

© 2021 Loch Long Salmon. All rights reserved.

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Addressing concerns with conventional farming systems

Conventional salmon farms use open net pens. This has proven, for decades, to be a successful method of producing healthy protein for Scotland and, as the UK’s largest food export, for the world.

However, farmers using conventional open net pens have to work hard to manage and mitigate a number of challenges - including fish health issues from sea lice, environmental disruption and predator interaction.

At Loch Long Salmon, we are taking a fresh approach. We believe that prevention is better than cure, and our use of semi-closed farming systems will stop problems before they start.


Sea lice

Sea lice are a naturally occurring marine organism, and in open net farms juvenile lice attach themselves to the young salmon placed into the pens. Sea lice breed quickly, the cycle repeats and very quickly there can be a significant number of sea lice per farmed fish, harming the salmon and dispersing into the surrounding environment.

Conventional salmon farmers go to great lengths and use a variety of methods to control the number of sea lice, such as chemical food treatments, chemical baths, freshwater baths, physical removal by water jets or brushes and biological control by ‘cleaner fish’ which eat the sea lice.

Our new approach will prevent rather than cure, by eliminating the sea lice problem for good.

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Scotland’s industry

As Scotland’s largest food export, Scottish farmed salmon doesn’t just contribute significantly to the economic success and international recognition of Scotland’s iconic food and drink sector - it is a cornerstone of the communities that host the farms. Salmon farming provides quality jobs, investment, and support for a large number of local ancillary businesses. As well as providing stable year-round economic activity and jobs, salmon farming sustains people and populations in these remote coastal areas of the country.

Scotland’s government and regulatory authorities are clearly keenly aware of this. We believe they want to support sustainable growth in the salmon farming sector. However, the problems faced by conventional open net farmers, and the resultant criticism, is proving a massive inhibitor to growth.

In response, some have mooted on-land recirculating aquaculture systems. However, these systems would be completely unsuited for commercial deployment in Scotland’s rural areas. They would be built and operated nearer large population centres in England, mainland Europe, Asia and the USA. Scotland’s coastal communities would miss out on the significant economic benefits associated with farming salmon in the natural ocean environment.

Scotland’s government and regulators need solutions. We believe that our fresh approach offers an important way forward for Scotland.

We are the first movers to the semi-closed system because not only does it deliver environmental and welfare benefits, but the higher costs for build and day-to-day operations will be outweighed by lower treatment costs, better survival and better feed conversion - therefore creating a lower overall cost of production. Our more sustainable approach will enhance the Scottish brand and create more value.

Beinn Reithe

Stewart Hawthorn
Director, Loch Long Salmon

Stewart has worked in the international aquaculture sector for more than 30 years in senior leadership roles in Scotland, Canada and New Zealand. He has been responsible for farming operations including freshwater recirculating aquaculture systems, marine farming systems and complex breeding improvement programmes.  He is currently Owner and Director of Trimara Services UK Ltd, an aquaculture equipment and services company working with customers in Scotland and internationally.
Stewart has led the commercial operations for Grieg Seafood in North America, including the development of a successful and award-winning super-premium branded salmon, Skuna Bay Salmon.


Christoph Harwood
Director, Loch Long Salmon

Christoph is Managing Director and a founder of Simply Blue Aquaculture, which was established in 2018 with a view to developing new salmon farming models in Scotland.  He is also a Director of Simply Blue Group.

As a Director of Loch Long Salmon, Christoph brings extensive experience from the marine energy sector. Having held senior positions in environmental finance and tidal energy technology businesses, Christoph also brings experience of working in start-ups and knowledge of key environmental issues.

Mark Shotter
Project Manager, Simply Blue Aquaculture

Mark is project managing the planning, consenting and engineering of the low-impact, semi-closed sites for Loch Long Salmon, starting with the site at Beinn Reithe.

Mark has a passion for sustainability and the ocean environment. As a project manager he has experience in energy, engineering and the marine environment. He also brings experience of managing engineering projects and operations around the world in often challenging environments.

For further information, or to speak to our team, please get in touch:

E  info@lochlongsalmon.com
T  0131 618 6497

Loch Long Salmon Ltd, 21 Young Street, Edinburgh, EH2 4HU

For illustrative purposes only.

Loch Long Salmon’s application for planning permission will consist of marine components and shore base components.

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Semi-closed salmon farming systems have been developed, trialled, proven and commercially adopted in Norway and Canada. We want to bring this farming system to Scotland for the first time, and with it, a fresh approach to farming salmon in Scotland.

Semi-closed farming systems look much like conventional pens from above. Under the water, they have an opaque, outer barrier that contains the inner net, and which protects the farmed salmon. Water is pumped through the enclosure from deep below the surface.

This system delivers environmental and animal welfare benefits.

The impermeable barrier prevents sea lice from entering the farmed environment and attaching to the salmon. The pumped water comes from beneath the depth at which sea lice live. It prevents seals and other predators from seeing the fish.  The system also captures the vast majority of uneaten food and fish waste, significantly minimising the impact of the fish farm on the seabed.

What are semi-closed systems?

Wild salmon and sea trout

There are concerns that the sea lice from farms spread outside the nets to wild salmon migrating past salmon farms and to resident sea trout that live in our coastal waters. There is some evidence to suggest that wild salmon and sea trout can collect much larger numbers of sea lice than would have occurred naturally when nearby salmon farms have sea lice outbreaks.

By preventing sea lice entering the farm and multiplying, we eliminate any potential harm to wild salmon and sea trout.

The secondary impermeable barrier further reduces the risk of salmon escaping from the farm and interacting with the wild population.

Our fresh approach will benefit both our salmon and the wild fish around them.


Most of the animal welfare questions which salmon farmers commonly face can be traced back to sea lice, because the methods of sea lice control used by farmers weaken the fish.

Fish are kept healthiest when left undisturbed in the water. Being handled by farmers and subsequently being chemically treated, brushed or bathed creates stress and causes scale, skin and mucus loss and damage.  This increases the likelihood of mortality.  

The semi-closed system prevents lice from entering the farming enclosure rather than controlling them when they do. By focusing on prevention rather than cure, our fresh approach will improve fish welfare for good.


The benefits of preventing sea lice from entering the enclosures is not limited to better welfare of wild and farmed stocks - there is also an environmental bonus.

Conventional salmon farmers are often forced to use a range of sea lice control measures, including chemical treatments. Residues from these treatments can be found in the wider marine environment.

Loch Long Salmon is so confident about the efficacy of the semi-closed system that we will not be applying for a license to use any of these chemical treatments for sea lice.

The elimination of chemical treatments for sea lice is one of the environmental advantages of the semi-closed system over conventional open net farming. An arguably more significant one is the collection of over 85% of the solid waste, in the form of uneaten food and fish faeces. Rather than this waste collecting on the seabed, it will be pumped to shore via the sump at the base of the outer barrier, removed of excess water, then used as a valuable resource.

An independent study funded by Zero Waste Scotland has identified that the organic matter collected could be used as a fertilizer ingredient for land-based farms or for use in anaerobic digesters for green energy production – allowing the farming system to contribute to Scotland’s circular economy.

Moreover, the water quality, flow rate, oxygen saturation and temperature regulation of a semi-closed system allows for more healthy fish to be grown per volume of water.

In other words, Loch Long Salmon farms will grow more, healthier fish in fewer farming enclosures than is achievable with conventional open net pen systems. This significantly reduces the visual impact and area required by our salmon farms.


Historically, conventional salmon farms have suffered from significant attacks by predators. This has sometimes been from above, by birds, but the most devastating attacks have come from below, by seals, which can kill or maim enormous numbers of fish in a single attack.  

With evolving regulations on the use of lethal force against seals conventional farmers have increasingly adopted sophisticated acoustic deterrent devices (ADDs) to scare the seals away from the farm.  They sometimes use anti-predator nets to stop seals getting to the farmed fish. The seals sometimes become entangled in anti-predator nets and drown.  

Our fresh approach will change the way predators interact with our farmed salmon. The impermeable outer barrier of the enclosure is opaque, so seals cannot see the salmon inside. Seals are visual predators, so if the seals can’t see the salmon, they can’t attack the salmon. The system therefore prevents the need to use ADDs - and eliminates any risk of harm to dolphins, whales, and porpoises. We won’t need anti-predator nets so eliminate the risk of seal entanglements.

Loch Long Salmon will shortly submit a planning application to the Loch Lomond and Trossachs National Park Authority to open its first farm, which will be on Loch Long. Should planning permission be approved, we hope that Beinn Reithe Fish Farm will be operational in 2023.

Detailed information on our proposal can be seen on the dedicated website 

Loch Long Salmon is a joint venture between Simply Blue Aquaculture, Trimara Services and Golden Acre Foods.

Our team, and our contact details, are:

Contact details

Images courtesy of Aquaculture Alliance

When Scotland started farming salmon 50 years ago, climate change was not on the local, national or global radar. Then, farming salmon was a solution to different problems, primarily those around the growing global demand for healthy protein.

This remains critical, but people, governments and business around the world now accept that the primary problem has changed to building a low carbon, circular economy that is sustainable, green and inclusive.  

Farming salmon was the answer then, and it is the answer now. Farmed fish have, by some distance, the lowest greenhouse gas emissions of all farmed animals, and the best food conversion ratio of all farmed animals.

The expanding global population is inextricably linked to the climate crisis; people need protein, and as they become wealthier they want healthier protein that is rich in marine omega-3 oils.

Farmed salmon provides part of the solution the world needs to the climate problem. And our fresh approach to salmon farming, with its focus on environmental stewardship and animal welfare, makes the case for its expansion more compelling.

Climate change

Sea Lice Statement