What is nano copper used for in aquaculture?

In aquaculture, nano copper is incorporated into fishing nets and EPS salmon packaging as an antifouling and antimicrobial agent. This article explains why biofouling is a real operational problem, how copper acts at the nanometre scale against fouling organisms and microorganisms, and what certified documentation backs NanoAlsa nano copper for this application. For a general introduction to the material, see the guide what are copper nanoparticles?.

Why is biofouling a problem on farming nets?

Biofouling is the accumulation of algae, molluscs, bryozoans and microorganisms on a submerged surface. On farming cages, this build-up reduces water exchange and the oxygen available to the fish, adds dead weight to the structure, and forces frequent mechanical cleaning that wears down the net material.

Periodic mechanical cleaning — pressure washing, net changes or immersion in treatment tanks — is a recurring operational cost for farming sites. Slowing down the rate at which biofouling attaches allows those interventions to be spaced out and reduces net wear from repeated handling.

How does nano copper act as an antifouling and antimicrobial agent?

Nano copper embedded in the matrix of a material releases copper ions in a controlled way from the surface of each particle. Those ions interfere with cellular processes in bacteria, algae and the larvae of fouling organisms, delaying their attachment and growth on the treated surface.

A 2025 study published in RSC Advances on farming nets with copper oxide (CuO) nanoparticles embedded in a thermoplastic compound documented a marked antimicrobial and anti-biofouling effect compared with untreated nets, attributed to the sustained release of copper ions from the material’s matrix (Mosallaei et al., 2025). The underlying mechanism — release of Cu²⁺ ions that damage cell membranes and generate oxidative stress in the microorganism — is described in reviews on copper as an antimicrobial agent (Salah, Parkin & Allan, 2021).

Mechanism: ion release and oxidative stress

The high surface-to-volume ratio of a copper nanoparticle speeds up the release of Cu²⁺ ions compared with copper in conventional form. Once in contact with a microorganism’s cell, those ions alter membrane permeability and favour reactions that generate reactive oxygen species, damaging internal cellular components.

This mechanism of action — described in the scientific literature for copper and copper oxide nanoparticles — is consistent with using nano copper as a functional coating on surfaces exposed to seawater, where the goal is not to sterilise the environment but to delay the attachment and growth of fouling organisms on a given surface.

Nano copper in EPS packaging for salmon

Beyond nets, NanoAlsa develops a nano copper masterbatch for EPS (expanded polystyrene) used in salmon export packaging. Copper nanoparticles dispersed in the EPS matrix provide antimicrobial and antifouling properties to the packaging throughout the cold chain and product transport.

This application is documented on NanoAlsa’s EPS Salmones page, which details the masterbatch composition and its integration into existing production lines without major process changes.

Both applications — nets and EPS packaging — rely on the same underlying property of nano copper: a high surface-to-volume ratio that sustains ion release over time. The difference is the matrix the particles are embedded in and the operating environment, submerged seawater for nets versus a dry cold-chain packaging surface for EPS, which affects how the antifouling or antimicrobial effect is evaluated in each case.

Certified NanoAlsa nano copper: technical characteristics

NanoAlsa nano copper used in these applications has CAS number 7440-50-8, a purity of 99.987% certified by Alex Stewart Laboratory, and particle size from 5 to 90 nm, with 79% of the distribution between 30 and 60 nm and spherical morphology, according to nanometry certified by the Catholic University of Chile and the University of Chile. It is supplied in dispersions at 50% by weight in acetone, distilled water with PVA 2.5%, or distilled water with PVA 5%.

For the specific application in fishing and aquaculture nets, NanoAlsa publishes a technical datasheet separate from the rest of the product documentation, available on the nano copper data sheet.

Embedded nano copper vs traditional antifouling paints

Nano copper embedded in a material’s matrix and traditional antifouling paints are two different formats for applying copper to a submerged surface, with different application and maintenance protocols. The table below summarises the main differences between the two formats.

Traceability and documentation for buyers

Every claim about NanoAlsa nano copper in this guide is backed by publicly downloadable documentation: a purity certificate from Alex Stewart Laboratory, nanometry certificates from the Catholic University of Chile and the University of Chile, and the specific datasheet on copper for fishing and aquaculture nets. You can also review the full list of NanoAlsa certifications.

This traceability lets a farming site or a net manufacturer independently verify purity and particle size before evaluating the material for an antifouling application. To see available presentations and request a quote, visit the nano copper page.