Maintaining high standards of fish welfare is a top priority for all fish farmers, and for many a key part of that is protecting fish from predators. Often the most challenging balancing act is creating a safe environment for your fish while also minimising impact on other marine life. America’s National Marine Fisheries Service – informally known as NOAA Fisheries – recently issued new guidance detailing what kind of predator deterrents are compliant with the USA’s Marine Mammal Protection Act (MMPA). These rules impact anyone selling seafood products into the American market. |
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What you need to know about the MMPA legislation
From 1 January 2022, the MMPA will ban fish product imports from countries whose farming operations cause “mortality and serious injury of marine mammals”. “Serious injury” is defined as “an injury that is more likely than not to lead to the death of the affected marine mammal”.
This means that countries which previously sanctioned seal shootings as a last resort to protect fish from attacks have to now take steps to move away from these practices and ensure their predator management practices meet NOAA’s standards.
What practices are covered in the legislative ban?
As well as insisting on an end to seal shootings, a number of other deterrent methods are also very clearly prohibited. These include:
- chemical irritants
- sharp objects
- chasing with vessels
- explosives like firecrackers
It’s important to understand the MMPA is not a ban on acoustic devices or any particular technology; the focus is on getting the industry to invest now in non-lethal methods of deterring predator attacks to reduce mortalities and serious injury of predators.
What else can you do now to safely protect your fish from predators?We looked at our customers with the best track records of keeping predators away from their farm sites and found they had these five best practices in common:
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How Ace Aquatec can helpFor the last 8 years, we’ve been advocating a combination of safe acoustics, reinforced nets, and good farming practices. Our award-winning acoustic technology won the 2018 Queen’s Award for Innovation for successfully reducing conflict between seals and farms. We have two world-leading acoustic deterrents that are 100% compliant with NOAA/MMPA welfare criteria and proven highly effective over years of use compared to other traditional acoustic devices in the market:
Click here for more information on our predator control products |
How to check if your current deterrents are NOAA compliant
NOAA has launched an Acoustic Deterrent Web Tool to help quickly check which higher volume (over 170dB) startle devices are approved.
Try out their tool to see if your current deterrent system meets the criteria. If it does, you’re immediately issued a certificate of approval valid for one year.
If you already use Ace Aquatec’s RT1 deterrent (a low frequency device) you would select multi-frequency on the Web Tool, and enter in the requested parameters for the Ace Aquatec deterrents you have on your sites using the table below for reference. For the low frequency RT1 deterrents please generate a certificate for each setting.
Ace Aquatec Deterrent | RT1 Flex | RT1 Ring | US3 |
Lowest Frequency Pitch (kHz) | 0.8kHz | 1kHz | 8kHz |
Highest Frequency Pitch (kHz) | 1.2kHz | 2kHz | 11kHz |
Average source level (dB)* | 176dB | 180dB | 181dB |
Duty Cycle | 11% | 11% | 10% |
Then, enter your name, the name of the deterrent (Names in table above), the species you are trying to deter? (harbour seal, grey seal), and select “Generate Certificate”
For guidance on how to process any of our other deterrents through the Web Tool please get in touch and our team will walk you through it.
* Average within a transmission: re 1uPa rms @ 1m

It’s also important to understand if other local regulations apply to your site. For example, if you need a European Protected Species (EPS) Licence for your site then any MMPA guidance is in addition to that, not instead of it.
The latest NOAA guidance is open for public comment until 30 October 2020 but gives a good indication of how the MMPA is likely to be interpreted. We will keep this page up to date as their guidance is finalised.