Seaspiracy: examining the science, the message, and what you can do to help save the ocean

Updated: Jun 30, 2021

Written by: The staff and students of the Fish and Fisheries Lab with guest contributor and JCU alum Dr Stephen Ban (Victoria, Canada)

Thai Fishing vessel and catch
Thai fishing vessel and catch: photo by Shin Arunrugstichai

All of us in the Fish and Fisheries Lab are passionate about the ocean. It’s why we chose careers in marine science, and also why we try to work in ways that bring about the best outcomes for the ocean. As a research lab, our values include respecting diversity of opinion, continuous learning, participating in discussion and debate, and sharing our scientific knowledge and expertise.

The recently released Netflix documentary Seaspiracy is making waves around the world, and is being hotly debated in social media and online. It’s a thought provoking and controversial film, that has at its core, a central message to viewers: ‘stop eating fish’. It is doing a great job of getting people talking about ethics and sustainability of global seafood, a conversation that is sorely needed.

As a fisheries science lab, we work on projects to improve fisheries sustainability and marine conservation, it’s in our mission statement. As such, we felt compelled to write this blog to examine some of the points made in Seaspiracy, but perhaps more importantly, we also provide practical suggestions for ocean advocates about how all of us can make our own informed choices about what we can do to help protect the oceans that we all love.

Examining the scientific evidence for claims made in Seaspiracy

Claim 1

Seaspiracy says: Whales create phytoplankton blooms, so losing whales means losing phytoplankton and a major component of the Earth’s oxygen generation.

Unlikely - an extreme extrapolation. We found scientific evidence that whales contribute to nutrient cycling (e.g. Ratnarajah et al. 2014), and that in high densities, whales and seals can concentrate significant amounts of nitrogen near the surface which then enhances primary productivity (Roman & McCarthy 2010). In the Southern Ocean, sperm whales may contribute up to 50 tonnes of iron every year which helps to stimulate and prolong phytoplankton blooms (Lavery et al. 2010). However, whales are also concentrated in areas of high productivity, i.e., where plankton blooms and productivity are already occurring (Tynan 1998). Meanwhile, oceanographic science suggests that plankton blooms are regulated by a wide range of factors including nutrients, winds, temperature, and the biology of different types of plankton themselves (Sommer et al. 2012, Hunter-Cevera et al. 2016, Silkin et al. 2019). So, whales are important, and they can supplement and enhance phytoplankton blooms. However, it seems unlikely that at the scale of the global oceans, cetaceans are the source of the world’s marine productivity and phytoplankton blooms.

Claim 2

Seaspiracy says: In Taiji, Japan, dolphins are being killed by fishers because of competition over fish stocks.

Misleading: Some nations, including Japan, have in the past claimed that cetaceans compete with fishers for fish and state that because of this, they should be allowed to continue commercial whaling. These claims have been discredited (see Gerber et al. 2009) and we agree that cetaceans are not threatening the world’s fisheries.

However, Seaspiracy provides no evidence that the dolphin hunting in Taiji is being driven by fishers thinking that dolphins are competitors. Meanwhile, there is evidence that dolphins in Taiji are being specifically hunted for other reasons. Taiji is the birthplace of Japanese whaling, Taiji whalers invented net capture methods for whaling all the way back in 1675, and cetaceans have been taken for food there for 100’s of years (Segi 2003, McNeill 2007). This historical context suggests that the Taiji dolphin hunt is not driven by local beliefs that they compete with fisheries, and thus this statement is misleading. Nevertheless, dolphins are still captured in some fisheries, and we agree that urgent action is needed to save some dolphin species from extinction and to minimise the impacts of fishing on these animals (Rojas-Bracho et al. 2006).

Claim 3

Seaspiracy says: Bluefin tuna sell for millions of dollars at auction.

Misleading: The price of millions of dollars for a single tuna is only for the first fish of the season, not all tuna. These exorbitant ‘first fish of the season’ prices are widely reported in the news, but the average trading prices varies between 2,500 to 14,000 Yen per kg (approx. $24USD to $130USD/kg), with an average price for bluefin tuna of $45 USD/kg) – (click here for market prices).

Claim 4

Seaspiracy says: Bycatch is a serious issue in fishing.

Agree – but bycatch differs between fisheries: bycatch is a very serious issue and is a big problem in fisheries. It’s why there is so much research going into bycatch reduction. It’s why bycatch reduction devices, including turtle excluder devices (TEDs) are law in some trawl fisheries in Australia (see here for the Australian Fisheries Management Authority [AFMA] workplans for bycatch and discards). Even some international trade agreements mandate the use of TEDs, e.g. the USA will not accept shrimp imports from fisheries that do not protect sea turtles by using of TEDs.

As for shark bycatch, in some fisheries using the right fishing gear means that fishers can reduce bycatch and also increase sustainability (McAuley et al. 2007). Additionally, while shark bycatch is sometimes also kept for their fins, the portrayal of the shark fin trade is often misleading and shark fin bans aren’t necessarily the best way to tackle this issue. Finning often gets the public’s attention, but sharks are caught for a whole range of reasons including meat, liver oil, and cartilage. To design effective management, we need to distinguish between sharks caught for their meat and fins and liver oil and cartilage, from sharks caught just for their fins. Overfishing is the problem, shark finning is part of that problem, but shark finning is not THE problem. The solution is in making shark fisheries more sustainable (and sharks CAN be harvested sustainably – see response to Claim 6 below), not just banning the fin trade (read Shiffman et al. 2020).

So yes, bycatch remains a serious problem and we should all be aware of this, but it’s not the same for all fisheries (see suggestions for ocean advocates).

Claim 5

Seaspiracy says: Fisheries sustainability isn’t understood.

Incorrect: There are many different definitions of fisheries sustainability (read Hilborn 2007). The challenge is helping consumers understand what sustainability is so that they can make informed choices.

Some fish can grow and reproduce very quickly. For example, the mahi mahi (Coryphaena hippurus) grows especially quickly, reaching 10 kg in weight in one year, becoming sexually mature within the first year of life, and producing up to 1.5 million eggs per female (Oxenford 1999). Other fish like swordfish grow much more slowly. Both species can be fished sustainably depending on how many fish are removed from the population. In fisheries, a commonly used sustainability target is the maximum sustainable yield (MSY), that is, the maximum number of fish that can be removed before the population starts being unable to replenish those losses. This varies widely between different species but it is perhaps the most widely used definition of sustainability in fisheries science. It is in fact, the exact same concept the former European Commissioner for Fisheries (Karmenu Vella) described in the film using the analogy of bank interest. He explained it well. You fish off the interest, that’s sustainable. So really, a good explanation of the basics of fisheries sustainability was actually provided in the film.

The MSY concept is usually applied at the single species level, but these single species sustainability limits are applied alongside management approaches like Ecosystem Based Management and the Ecosystem Approach to Fisheries Management. These broader approaches explicitly consider the range of physical, biological, social, and economic factors involved with a fishery, such as impacts on habitats, bycatch, and culture, and are part of mainstream fisheries management in the USA and Australia.

Management approaches like Ecosystem Based Management can address issues like byacth, habitat impacts, and balance fisheries and broader conservation.

Claim 6

Seaspiracy says: the oceans will be completely fished out by 2048.


Seaspiracy says: there is no such thing as a sustainable fishery.

Incorrect: The statement that the oceans will be fished out by 2048 came from a controversial paper published in 2006 that has been misinterpreted. Since this 2006 study, new analyses – including one by the author of the original paper – say “In 5 of 10 well-studied ecosystems, the average exploitation rate has recently declined and is now at or below the rate predicted to achieve maximum sustainable yield for seven systems” (Worm et al. 2009). In other words, the catch rate has decreased to levels where populations will be stable. Another more recent paper suggests that many stocks are actually increasing (Hilborn et al. 2020). Essentially, this means that in many fisheries around the world, management changes have reduced catches to levels where fish populations are maintained or rebuilding, i.e. sustainable.

In Australia, the Status of Australian Fish Stocks (SAFS) report gives an updated account of the stock status and assessment of fisheries from around Australia. These are science based stock assessments compiled and reviewed by professional fisheries scientists, including scientists from our Fish and Fisheries lab at James Cook University (see the Australian Shark Card). Of 406 stocks assessed in the SAFS, 254 are sustainable, 18 are recovering, and 28 have negligible catch. In other words, scientific data indicate that 73% of Australia’s fish stocks are not declining or likely to decline. With good management even sharks can be fished sustainably and some fisheries, like the southern gummy shark fishery, have had stable shark catches for decades (Walker 1998, Simpfendorfer & Dulvy 2017). The Australian Shark Report Card shows that of 199 Australian shark stocks assessed, 124 are considered sustainable.

Are fisheries perfect? No, there is still a LOT of work to do. Many fisheries across vast areas of ocean are still poorly managed, and some fisheries in Australia need more work. But to say that sustainable fisheries don’t exist is simply factually incorrect.

Claim 7

Seaspiracy says: There will be more plastic than fish in the oceans by 2050.

Incorrect – but they raise a crucial issue: This figure came from a 2015 report that extrapolated data from other papers. However, the same research group that did the original report has now revised this claim, and authors of the other studies used to generate the report suggest that this claim may not be warranted (see here). However, ocean plastic pollution is a massive issue and it needs attention, so irrespective of the inaccuracy of this figure, Seaspiracy is well justified in raising this as one of the most pressing issues facing our oceans today (see suggestions for ocean advocates below).

Claim 8

Seaspiracy says: 46% of the Great Pacific Garbage Patch is fishing gear.

Misleading: Scientific surveys have indeed found that 46% of the GPGP is fishing nets (Lebreton et al. 2018), BUT this doesn’t include all types of plastic, much of which sinks and thus isn’t counted. Furthermore, the ocean plastics problem is much bigger than the well-publicised ocean garbage patches. The amount of plastic entering the ocean from land-based sources is ‘one to three orders of magnitude greater than the reported mass of floating plastic debris in high-concentration ocean gyres and also globally’ (Jambeck et al. 2015). This means there is a massive amount of plastic entering the ocean from land-based sources, which also means that our actions on land are still important at an individual level – we do not get to offload our responsibility for ocean plastic pollution to the fishing industry.

So, all of those efforts to rethink-refuse-reuse-reduce-recycle etc are as important as ever. Do not stop supporting organisations that are trying to reduce plastic waste, do not stop your own efforts to reduce your plastic footprint, do not stop pressuring companies and governments to reduce waste. If we really want to tackle this problem, we also need to assist the countries that produce most of this plastic waste by helping improve their waste management systems (Jambeck et al. 2015). Working with local people and governments on waste management in a developing country is probably much less Instagram-worthy than sailing through the Pacific counting marine debris, but that’s the sort of work that’s needed most.

We do not get to offload our responsibility for ocean plastic pollution to the fishing industry. We all need to keep acting on reducing waste, and supporting the people and organisations working towards zero waste.

Claim 9

Seaspiracy says: Non-Governmental Organisations (NGOs) aren’t engaging in the ghost net problem.

Incorrect: This simply isn’t true, lots of NGOs engage in the ghost net issue, including several Australian Indigenous communities along the Gulf of Carpentaria (Dhimurru Aboriginal Corporation), Cape York (Pormpuraaw Art & Culture Centre), and Torres Strait (Erub Arts), who are working to remove and clean up ghost nets in the ocean, and re-use the nets in cultural art pieces and international exhibitions. Tangaroa Blue is doing amazing work on ghost nets and marine debris. Here are a few other examples that came up for us within seconds of doing a Google search:

In Queensland, new legislation will hopefully also help address ghost nets (although we are waiting to see how this will be implemented and whether it works)

Claim 10

Seaspiracy says: Observers can be bribed, they have difficult jobs, and we don’t really know what happens at sea.

Agree – we need better monitoring, and we need to support our observers. Independent verification of fish catches, bycatch, and discards is crucial and that’s why observers are so important. There are observers out at sea, but observer coverage IS low. It’s a tough job. Imagine living on a boat for weeks to months with a captain and crew that may be hostile to you, in cramped and poor conditions, for relatively low wages. Some observers can be bribed to falsify reports, others may be forced by threats and actual violence. We need to do better, both in terms of observer coverage, and in protecting at sea observers (Ewell et al. 2020). New technology is providing some opportunities for better fisheries monitoring and enforcement, for example:

  • Remote electronic monitoring using cameras and sensors can result in better data and compliance (e.g. Emery et al. 2019)

  • Satellite monitoring can be used to detect illegal fishing (e.g.

While these show promise, they do not solve all our problems. Uptake of technology such as electronic monitoring has been slow and there are many issues to consider in using it (van Helmond et al. 2020). Electronic monitoring may not work for some fisheries due to the vessels involved, and a whole range of logistical issues. We need to do better. In the meantime, there are things we can do to act on this (see suggestions for ocean advocates).

Claim 11

Seaspiracy says: Fishing slavery is a major issue.

Agree - but its’ not all fisheries: Fishing slavery and the rights of fisheries workers ARE major issues in some fisheries (Decker Sparks & Hasche 2019). Slavery, coercion, and forced labour by any means, including debt traps, intimidation, and violence, even murder, are not OK. These practices should be aggressively unearthed and stamped out. However, while these issues are very real, they are not an issue in every fishery. For example, fisheries slavery just isn’t an issue for Australian operated fisheries with local owners and companies. So, what should you do? Know where your seafood comes from and support efforts to track seafood and stamp out modern day slavery (read more here). Ghost Fleet is an excellent documentary based in Indonesia and Thailand that is well worth watching.

If you want to directly support seafarers and fishers, check out:

Claim 12

Seaspiracy says: Bottom trawling is wiping out 3.9 billion acres of seabed every year, a catastrophe greater than rainforest deforestation.

Misleading – but trawling does significantly impact seabeds: An benchmark scientific paper in the 1990s found that worldwide, every year trawling covered an area about 150 times larger than the area of land cleared for deforestation (Watling & Norse 1998) – and this was the source for the figures used in Seaspiracy. However, the paper uses many assumptions and extrapolations in deriving a figure for the global trawling footprint, and it also highlights why the comparison made in Seaspiracy is misleading. The paper looked at the area trawled every year compared to the area of new rainforest cut down. Trawlers repeatedly trawl over the same trawl grounds, year after year, while deforestation is permanently cutting down relatively untouched rainforest. There is no doubt that trawling a new area will significantly impact the seabed habitats and marine biodiversity there, but comparing the area being trawled – and that may have been trawled for years – to the area of new rainforest cut down every year is a misleading comparison. Does trawling have serious impacts? Yes, but some areas are more impacted than others. For example, the waters off Europe are extensively trawled, but In Australia less than 10% of the marine area is trawled (Amoroso et al. 2018). Furthermore, in Australia, marine parks and changes in fisheries management and the market have reduced both the area available for trawling, and the number of active trawlers (e.g. Chin et al. 2019). While trawling impacts are demonstrably serious, the details about where it’s happening, how long it’s been going on, and what other management might be in place still matter.

Claim 13

Seaspiracy says: Aquaculture is destroying mangroves.

Agree – but check your sources: Aquaculture can cause extensive habitat loss and degradation and this is well documented (e.g. Herbeck et al. 2020). There are also concerns about pollution from nutrients, uneaten food, and antibiotics and the effects on surrounding marine ecosystems. Australian aquaculture has pollution controls and there are government approvals processes about where aquaculture can be developed. We suggest that everyone eating seafood at the very least find out if it is aquaculture or wild caught, and whether the source is sustainable (see suggestions for oceans advocates).

More general ethical issues

Aside from factual errors, the film raises some ethical questions for us, for example: failing to get a permit to legally film in Thailand (a fairly standard requirement across Asia); failing to tell their interviewees that their footage would be used in the film; recording someone who believes that they turned the camera off. Christina Hicks, who used to work here at JCU tweeted Unnerving to discover your cameo in a film slamming an industry you love and have committed your career to.” These are the ethical lapses that the film makes no attempt to hide, what other lapses may have occurred that we don’t know about?

Then, while the film does occasionally make the distinction between commercial and industrial fishing and sustenance or artisanal fishing, it throws all that out the window when it offers the unrealistic and utopian "solution" of telling people to simply stop eating seafood. More than 10% of the world's population relies on fish and fisheries for their livelihoods, and up to 3 billion people rely on wild or farmed seafood as their primary source of protein (see here). Getting everyone to switch to a plant-based diet is simply not realistic (see suggestions for ocean advocates below).

Finally, Seaspiracy continues to perpetuate a white-saviour industrial complex (WSIC, coined by Nigeran-American novelist Teju Cole in 2012), which refers to people who may help non-white people in a self-serving manner, to gain an emotional experience that validates privilege (Anderson 2013). This mentality does occur in environmental NGOs and conservation science (Brown et al. 2017), and is echoed in the overriding narrative of the film: Asian people are the villains, black people are the victims, and white people are here to sort it all out. The film’s talking heads are almost all white and UK-based (with the notable exception of Dr Christina Hicks), however, Dr Hicks makes a 30-second cameo and is one of the people who is uncomfortable with her portrayal in the film.

What does this mean for us, the passengers and crew of spaceship Earth?

As the crew and engineers of this planet, we agree with Paul Watson when he said that all of us have shared responsibility to look after the ‘Spaceship Earth’ that keeps us alive. We agree with Sylvia Earle when she said that everything starts with someone. So, considering what Seaspiracy claims and promotes, and what the science says about it all - what should we do? How do we do our part to protect the ocean that we all love?

As a lab of ocean advocates and fisheries scientists, there are five things that we think that everyone can do.

Suggestions for ocean advocates

1. Be passionate – but be informed. The oceans are under incredible pressure and we need passionate people to bring about change. However, there is a big difference between evidence-based facts (i.e. science and data) and personal opinion. If you are interested in fisheries and ocean conservation, track down the facts, and that may mean finding the original research articles or data reports – not just what someone says about the research. Make up your own mind. For example, anyone can access either summaries or full scientific stock assessments for Australian fisheries and Pacific tuna fisheries for free, and almost all scientists will happily share their research papers on request.

2. Check your privilege. We support anyone who makes an informed choice to not eat fish. However, we need to remember that this choice is a privilege. It is easy to fall into an ‘us and them’ mindset, that people should just stop fishing or eating fish. The reality is that fish are vital sources of food, nutrition, and livelihoods for millions of people (Kittinger et al. 2017, Hicks et al. 2019). The money from a small amount of shark fin is vital for the health and survival of some of the world's poorest and most marginalised people (Vieira et al. 2017). Furthermore, sometimes our conservation efforts can backfire and disadvantage these same people, forcing them into illegal activities and creating new conservation problems (Jaiteh et al. 2017). Conservation is not simple. Ignoring the realities of life for subsistence fishers and their dependents means that we might end up implementing conservation actions that look good on paper but fail on the ground.

3. If you eat seafood, think global – buy local. That means asking three questions:

i. What fish is this and is it sustainable? Know its scientific name and check this against a reputable seafood guide (i.e. one that clearly shows the science behind its assessments). In Australia, check the Status of Australian Fish Stocks (SAFS) – there’s even an app available. Elsewhere, check the MSC label (click here for the MSC’s response to Seaspiracy), or check the Monterey Bay Aquarium’s Seafood Watch. No system is perfect, but these systems do have systematic assessment processes that you can read about yourself.

ii. How was it caught/produced? Some fishing methods have less bycatch and habitat impact than others. Check the tin or ask the fish monger about how the fish was caught, go online to find out about the amount of byca