Organic emissions
Organic emissions from salmon farming may impact the marine ecosystem in the ocean under or around the pens. For this reason, we give the environment time to recover between each generation of fish farmed. Fish feces are a part of the natural ocean eco-system. When a shoal of fish enters an ocean area or a fjord system, fecal emissions from the fish occur naturally. Fish feces contain nutrients, and like manure from agricultural animals, they act as fertilizers for new life. In the ocean, these nutrients sustain the growth of small plankton, which may be eaten by bigger species and thereby move up the natural food chain.
However, too many nutrients in one area can cause eutrophication, which can potentially harm the existing fauna in an eco-system. While the feces of wild fish are widely distributed around the fjord system, salmon farms contain a lot of fish in a smaller area, and the risk of eutrophication increases. On the seabed beneath a farm, there will also be some temporary impact on the benthic fauna due to organic emissions.
Fallowing
When we fallow a farm, we leave it without fish for some time. When a farm is fallowed for a period, the seabed recovers and goes back to its original state.
To avoid eutrophication and a too large impact on the seabed, the release of organic emissions from open pen salmon farms is strictly monitored and regulated in all of the countries in which we operate. We monitor the seabed under and around our sea farms, and perform benthic testing during peak biomass.
Local regulations impose fallowing periods after each generation, to ensure the environment under and around the pen can recover.
- In Rogaland, regulations impose a fallowing period of at least two months.
With Area Based Management, we fallow entire areas simultaneously, to let an entire fjord system rest and recover. If the local environment is not sufficiently restored after fallowing according to independent monitoring, we must extend the fallowing period before putting new fish into the pens or reduce the number of fish at the site concerned. As such, the regulatory system automatically reduces production to fit the local environment of each farm.
New technology may also help us reduce our footprint on nature. In some regions, we are now able to apply models of the fjord systems to understand how we can place the farm to ensure as little impact as possible. In some areas, moving the farm a few hundred meters or placing it with a different angle towards the currents, may reduce the organic impact significantly.
Selecting good farm locations
Key to ensure the lowest possible impact from our operations is to use sites that are well-suited for salmon farming. Before applying for a new site, we spend years collecting environmental data to understand whether that is the case for the particular site in question. We look for locations with deep waters and good currents, which exchange the water consecutively and disperse the feces into a wider area of the fjords, mitigating their negative impact. On good sites, we can farm more fish with better welfare and lower environmental impact. Often, we have to farm a few generations on a site before we understand the particular characteristics of that location and how much time is needed for fallowing.
In the past, technology was less developed and many farms were placed in areas with little water exchange. Grieg Seafood are working to phase out sites that are less optimal for salmon farming, and instead expanding production on well-suited farms. Altogether, this move allows us to farm with better fish welfare and lower organic impact, but also with better sea lice and disease control.
Reducing excess feed
Feed that is not eaten and that is released out of the pens may also impact the environment. We are working to reduce excess feeding by using underwater cameras, so that we can stop feeding when the fish are satisfied. We are also centralizing feeding operations from one or a few operation centers in each region, to develop specialized feeding expertise. Feed is the most expensive input into production, and precise feeding is both an ethical priority but also important to keep cost down.
Co-existence with wildlife
Farms are often located in areas abundant with birdlife and marine mammals. As a responsible salmon farming company, we do what we can to avoid conflicts with wild animals. We arrange operations and facilities in a way that minimizes our impact on local wildlife.
- Potential conflicts with wild animals are evaluated when we consider new sites.
- We aim to minimize impact on wildlife round our farms, such as birds or marine animals, by using equipment preventing such individuals from entering our pens. We set this target every year, including 2023.
- We do not use acoustic deterrent devises (ADDs).
- We generally only euthanize animals that are injured and choose alternative ways to protect farms against intruders. Euthanizing animals must be approved by a manager and in some cases a regulator. We do not euthanize species listed on national red list conservation list.
- Weapons are not allowed on our sites.
We are working to improve our reporting on dead birds, and will continue to work on measures to avoid any dead animals. The ASC standard imposes a limit on wildlife impact.
Co-existence with crustaceans
Medical sea lice treatments may potentially impact other crustacean species in the ocean. That is one of the reasons why we try to avoid using it, and work towards controlling sea lice preventatively.
Laboratory tests show that sea lice medicines may impact crustaceans if these species come into contact with it. Some medicines may make an impact even in smaller doses. However, it is uncertain whether crustaceans actually do come into contact with sea lice medication after treatment in the ocean, because factors like currents, temperature, and other natural aspects impact how the substances break down. More research to improve our knowledge is underway.
In any case, we are working to avoid using sea lice medicines. Use of such medication has declined significantly in recent years in the industry. In line with the precautionary principle, Norway has also prohibited the release of sea lice treatment baths near shrimp fields.
Grieg Seafood prefers to use preventive and biological sea lice measures rather than medical and non-medical treatments. Harvesting will always be considered when sea lice-infected fish are close to harvestable weight. We adhere to the following principles for use of sea lice treatments:
- Sea lice measures are based on IPM (Integrated Pest Management) principles. A multifaceted approach will give improved results and reduce the risk of sea lice becoming resistant.
- Minimize use of pharmaceutical treatments methods that discharge treatment water into the sea. Pharmaceutical lice treatments are acceptable in clean treatment systems, which purify the treatment water before it is discharged back into the ocean.
- Non-medical treatments are preferred if they provide an acceptable level of fish welfare. A risk assessment must be performed prior to any treatment. The treatment’s effectiveness and the risk of side effects on fish and the environment should be evaluated.
- Pharmaceuticals for sea lice treatments must be prescribed by authorized fish health personnel, and only medicines licensed for sea lice control should be used.
- Withdrawal periods for medicine use are rigorously controlled and documented.
