Closing the net on copper

Copper pollution from fishing nets discharges into the sea 1 gram of copper for every 2 kilograms of farmed salmon produced, according to a report published in Norway.

The environmental effects of the leaching of copper from fish farm nets and cages were highlighted by figures released by the Norwegian Pollution Control Authority, which show that the leaching of copper from fish farm nets in the sea amounts to about 160 tonnes of copper per year.

Copper is a common ingredient used to impregnate fishing nets because it prevents biofouling – the accumulation and growth of unwanted microorganisms, including algae, barnacles and other organisms on underwater structures.

Copper however can have a negative impact on animal and plant life both below and in the vicinity of the cages. Copper ions are released into the open water and sink to the bottom. Copper compounds in the nets are also taken up by macroalgae and fauna that grow on the actual nets and sink to the bottom with them.

In fact copper is one of the most toxic metals to aquatic organisms and ecosystems. The effects of copper on marine life can be lethal and can impact populations and ecosystems as well as individual aquatic organisms. For example, when sea scallops were exposed to realistic concentrations of copper, sperm and egg production decreased. The successful mass spawning of coral reefs can also be decimated by even low levels of copper pollution in seawater, according to research in Australia.

Silver is also naturally antibacterial and inorganic and non-leaching – unlike copper, it stays within the item to which it is added. The active ingredient provides maximum antibacterial protection for the lifetime of the product.

Addmaster (UK) Ltd is working with the British fishing industry to help reduce the spread of fish disease, using Biomaster silver-ion technology.

Bacterial diseases such as Yersinia, Carnobacterium, Aeromonas are a serious problem for many fisheries, killing tens of thousands of fish every year.  A new generation of antimicrobial fishing nets treated with silver ion technology are ensuring healthier fish stocks.

Biomaster antimicrobial technology actively inhibits the growth of bacteria thereby reducing the risk of cross infection in fish. When added to any surface it prevents bacteria from multiplying, permanently. Laboratory tests prove that fishing nets treated with Biomaster start to kill harmful bacteria on contact and kill to a 99.9% efficacy rate within 24 hours, wet or dry.

Addmaster (UK) Ltd. Marketing Manager Karl Shaw explains: “we use silver in our antimicrobial technology because it has low toxicity and low impact on the environment. It can introduced into almost any item in the food chain, safely. Unlike copper it also complies with all the relevant legislation for biocidal products, including the new Biocidal Products Regulation.”

*Please note that Addmaster was acquired by the Polygiene Group AB in January 2021, so all news articles prior to that date will still be branded as Addmaster.