Fish swimming in water filled with pills, representing antimicrobial use in aquaculture.

Seafood Safety: Are Antimicrobials in Aquaculture a Hidden Risk?

Reese Marlowe in Health & Wellness June 2025 • 4 min read.

"Comprehensive monitoring and resistance surveillance are crucial for protecting consumers from antimicrobial-resistant bacteria in fish and seafood."

Eating fish is often touted as a healthy choice, but could there be unseen risks lurking beneath the surface? With wild fish populations declining, aquaculture, or fish farming, is booming to meet the increasing demand for seafood. However, this rapid growth raises questions about the use of antimicrobials and their potential effects on our health.

In Australia, the aquaculture industry is expanding, focusing on species like salmon, tuna, prawns, and oysters. These farmed fish and shellfish are often raised in high densities, increasing the risk of disease outbreaks. To combat these diseases, antimicrobials are sometimes used, but this practice could lead to antimicrobial resistance, a growing threat to public health.

This article explores the concerns surrounding antimicrobial use in Australian aquaculture, highlighting the need for comprehensive monitoring and stricter regulations to safeguard consumers from the potential risks of antimicrobial-resistant bacteria in seafood.

The Rise of Antimicrobial Resistance in Aquaculture

Fish swimming in water filled with pills, representing antimicrobial use in aquaculture.

Antimicrobial resistance occurs when bacteria evolve to withstand the effects of drugs designed to kill them. The use of antimicrobials in aquaculture can accelerate this process, potentially leading to the development of resistant bacteria that can spread to humans through the consumption of contaminated seafood.

While no antimicrobials are registered for use in fish or other aquatic species in Australia, the Australian Pesticides and Veterinary Medicines Authority (APVMA) has issued permits for the minor use of florfenicol and oxytetracycline under specific circumstances. Concerns remain about the potential for overuse and misuse.

Limited Surveillance: Australia lacks a comprehensive surveillance system for antimicrobial resistance in animals, including aquaculture.
Imported Seafood Risks: Under World Trade Organization rules, Australia cannot routinely test imported seafood for antimicrobial-resistant bacteria, increasing the risk to consumers.
Inadequate Residue Testing: The Department of Agriculture, Fisheries and Forestry conducts residue surveys, but the number of aquaculture samples tested is small and may not accurately reflect the extent of antimicrobial use.

Reports indicate that antimicrobial use in Australian aquaculture has declined since the 1980s due to improved management practices and vaccine development. However, some reports also suggest that significant amounts of antibiotics are still being used, raising concerns about transparency and the potential for resistance.

Protecting Consumers: A Call for Action

The Australian aquaculture industry needs to be more transparent about its antimicrobial use. Clear and consistent reporting is essential for monitoring trends and identifying potential problems.

Regulatory authorities must ensure that appropriate permits for antimicrobial use are obtained and followed. Stricter enforcement of regulations is needed to prevent the misuse and overuse of these drugs.

Investing in alternative disease management strategies, such as vaccines and improved husbandry practices, is crucial for reducing the reliance on antimicrobials in aquaculture. By working together, the aquaculture industry, regulatory bodies, and consumers can ensure the safety and sustainability of seafood production in Australia.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.5694/mja12.11484, Alternate LINK

Title: Can We Feel It In Our Waters? Antimicrobials In Aquaculture

Subject: General Medicine

Journal: Medical Journal of Australia

Publisher: AMPCo

Authors: Mary D Barton, Olasumbo L Ndi

Published: 2012-11-01

Everything You Need To Know

What is antimicrobial resistance, and why is it a problem in aquaculture?

Antimicrobial resistance is when bacteria evolve to survive the effects of drugs designed to kill them. In the context of aquaculture, the use of antimicrobials, like florfenicol and oxytetracycline, can speed up this process. This is concerning because resistant bacteria can then spread to humans through contaminated seafood, posing a threat to public health.

What is aquaculture, and why is it important in the context of seafood safety?

Aquaculture is the farming of fish and shellfish, a practice that is expanding to meet the demand for seafood. In Australia, aquaculture focuses on species like salmon, tuna, prawns, and oysters. The significance of aquaculture in this context is that the high-density farming environments increase the risk of disease outbreaks. To manage these, antimicrobials are sometimes used, which can lead to antimicrobial resistance.

What are antimicrobials, and what are the implications of their use in aquaculture?

Antimicrobials, such as florfenicol and oxytetracycline, are used in aquaculture to combat diseases in farmed fish. While no antimicrobials are registered for use in aquatic species in Australia, permits are issued under specific circumstances. The implications of using antimicrobials include the potential development of antimicrobial resistance, where bacteria become resistant to the drugs, and can then be transferred to humans.

What does comprehensive monitoring involve, and why is it important for seafood safety?

Comprehensive monitoring involves surveillance and testing to detect antimicrobial-resistant bacteria in aquaculture. Currently, Australia lacks a comprehensive surveillance system for antimicrobial resistance in animals, including aquaculture. This is significant because without proper monitoring, it's difficult to understand the extent of antimicrobial resistance and protect consumers. Implications include the risk of undetected resistant bacteria entering the food supply, posing a potential health risk.

What is the role of the Australian Pesticides and Veterinary Medicines Authority (APVMA) in aquaculture, and why is it important?

The Australian Pesticides and Veterinary Medicines Authority (APVMA) issues permits for the minor use of florfenicol and oxytetracycline under specific circumstances. The role of APVMA in the context is to regulate the use of antimicrobials in aquaculture. It's important because it is essential for ensuring the responsible use of antimicrobials and minimizing the risk of resistance. The implications of APVMA's regulation are that it directly impacts the safety of seafood and public health by controlling the use of substances which can cause antimicrobial resistance.