Frequently Asked Questions

Why should I join OneFishTwoFish?

OneFishTwoFish helps people give back to the ocean, so their seafood consumption is more sustainable. By joining the program you’ll be helping to return more fish to the ocean. You can feel proud about doing your bit for ocean health and becoming Seafood Positive.

How does it work?

OneFishTwoFish captures fees from individuals, couples, families and businesses through annual subscriptions and makes grants to selected projects. These projects use the proceeds to undertake conservation activities that measurably improve fish habitat and populations. The remaining fees are used by Seafood Positive to provide supporters with ocean-related news and information and to market the program to new supporters.

What's the science behind returning fish to the sea?

Our projects use two methods for returning fish to the sea: 1. Fish habitat restoration and 2. Assisted breeding (also known as fish restocking). To calculate the number of fish returned to the sea through habitat restoration, we use a simplified fisheries model based on a common scientific method (zu Ermgassen et al. 2021). Projects calculate the number and type of additional fish created at one year of age in the newly restored habitat compared to unrestored habitat. The calculations are measured over a 10 year period and we apply discounts to ensure our estimates remain conservative. For assisted breeding, we use the number of fish returned at the time of release. All projects are required to follow our detailed technical guidance document and adhere to our project standards. For a copy of the technical guidance document or for more information on how we calculate fish, please email:

How are projects selected?

Projects are chosen by undergoing a rigorous selection process that includes assessment using 10 scientific principles and 17 project criteria. These are summarised in our Technical Guidance to Voluntary Seafood Offset Projects which all projects much follow. Our project criteria and standards were developed by Dr Chris Gillies and several external scientists including from CSIRO, NSW Government Department of Fisheries, The Nature Conservancy and several universities. Our project standards are based on global biodiversity and carbon offset standards applied by hundreds of organisations and governments globally.

Do you replace fish on a like-for-like basis?

We can't always replace two fish for every fish sold or consumed on a like-for-like basis, but the initiatives supported endeavour to holistically increase fish stock in the ocean. For some pelagic or deep sea fish species (like tuna) habitat restoration or assisted breeding is not yet possible. We therefore focus on improving coastal ecosystems and fisheries, where most of our seafood comes from, and importantly, where the ocean most needs our help. Read our FAQ 'What's the science behind returning fish to the sea' to find out more about our methods.

Why are the oceans in trouble?

Oceans suffer many threats, including pollution from land, coastal development, habitat destruction, overfishing, ocean acidification and marine plastics. Cumulatively, these threats have degraded and destroyed many marine ecosystems and caused harm to fish and marine life.

What do I receive if I join? (Personal)

Individuals, couples and families who purchase a subscription receive a digital certificate congratulating them on becoming Seafood Positive for a year. They also receive our e-newsletters and special offers and recipes. We provide stories from the projects we support, as well as information on sustainable seafood, seafood recipes, interviews with chefs, and articles on the latest marine science and technology to keep you up to date on everything related to the oceans.

What do I receive if I join? (Business)

Businesses purchasing a subscription receive access to project images, videos and stories from the projects, marketing collateral, logo use and invitations to special events. We also provide access to our OneFishTwoFish sustainable seafood network that connects like-minded businesses and customers.

Are there any other benefits to OneFishTwoFish?

Plenty! Habitat restoration typically has a number of other benefits beyond just creating fish and improving biodiversity. Shellfish reefs are great at using up the nutrients coming out of our rivers and estuaries. Mangroves, saltmarshes and seagrasses (known as coastal wetlands) are great at sequestering carbon and supporting a variety of bird species. Rocky reefs, like giant kelp forests, are amazing places to snorkel and dive, and support recreation and tourism. By supporting OneFishTwoFish, you'll be helping to restore these ecosystems and the many benefits they provide to people and nature.

How do you know the number of fish sold or consumed?

We use the weight of seafood as a substitute for the number of fish because seafood is rarely sold or recorded by number. Most seafood is sold on a per weight basis. Our calculations are therefore based on one kilogram of seafood representing the average weight of one fish. To determine the average amount of seafood consumed per person per year in Australia, we use the 10-year average (2009-2010 to 2019-2020) apparent consumption of seafood data, published by the Australian Bureau of Agricultural Resource Economics and Sciences. This equates to approximately 14 kg of seafood per person per year.

Why was OneFishTwoFish created?

OneFishTwoFish offers a simple way for seafood consumers, retailers, restaurants and other businesses to offset their seafood consumption. Restoring marine ecosystems is one of the best ways of helping fish populations and marine life to recover. We created OneFishTwoFish to support projects that address the loss of fish and biodiversity in our oceans.

I’ve changed my mind. Can I get a refund?

We offer a 100% refund if you’re not completely satisfied with our service. We only ask that you provide us with feedback so that we can improve our services for next time. If you need a refund, please get in touch via email:

How do I know the program is genuine?

OneFishTwoFish only works with reputable organisations with a track record in successfully completing habitat restoration and assisted breeding. We also have a government and industry advisory board to ensure projects align with the latest strategies to improve ocean health. We’re committed to transparency and will post project reports and other documentation on our website so people can review outcomes for themselves.