Let me lay my cards, face up on the table. I spent my formative years in Shetland in the 1970-80’s in a fishing village where skippers were kings and life pretty much revolved around fishing, the sea, the weather and Shetland culture. It was the experience of helping out on my father’s fishing boat that made me want to be a marine biologist – all those weird creatures that came up in the old fashioned and inefficient box dredge – starfish, sea cucumbers, algae, “scabby man’s heids” (echinoderms) and of course scallops and queenies. In the days before GPS we used to watch out for rafts of gulls that would indicate shoals of mackerel just below the surface feeding on baitfish. Like many brought up by the sea and involved in the fishing industry, I love it. I work with fishers and have had a few contracts around developing fisheries management plans, avoiding catching cod and helping ensure fair payment for gear displacement by offshore developments. There are some rogues and there have been some bad practices by fishers in the past but I think that the fishing industry gets an unfairly bad press. I often disagree with fishers but I also have a lot of time for what are an interesting, brave and entrepreneurial group of people.
The movie Seaspiracy sets out to tell the world how fishing is not sustainable, eating fish is bad for you and whale populations are declining because of plastics. As @Taotaotasi illustrates it’s a disjointed affair with the storyline zipping from whales and plastics, whaling, tuna fishing, shark finning, ineffective institutions, coral reefs, overfishing, salmon farming, mangroves, slavery and MPAs. It’s a mix of discussion highlighting issues that are of concern and misinterpretation of or wild exaggeration of the science.
Early in the film he highlights the importance of whales in the Carbon Dioxide cycle. They dive deep to feed, bring the food to the surface where they defecate thus fertilizing the upper regions of the ocean where you find tiny plants (phytoplankton). More wales = more fertilization, possibly. Krill, along with many other pelagic animals, also take part in this regular dance from the deep to the shallows, collectively in temperate regions it is referred to as diurnal vertical migration. According to the International Whaling commission the numbers of whales around the world look to be increasing, recovering from the decimation since the end of the 2nd world war. The narrator makes a link between plastic debris and deaths of whales through ingestion of plastic, however according to the IWC, “clear cases of ingested marine debris causing deaths remain few and scattered”.
There is a lot of focus on people driving cetaceans ashore to butcher them in Taigi (Japan) and the Faeroe Isles. The former has only being going on since 1969 and is said to be driven by the sale of dolphins to ocean life centres and the sale of dolphin meat. He also claims that in Japan it’s driven by the desires of fishers to reduce competition for fish. The Faeoese whale drive is a much older and ingrained traditional affair and the meat is eaten (there is a good documentary here that explores the issues in the fishery in Faeroe). It’s not a particularly pleasant spectacle but the animals are quickly dispatched and the folk that eat them are the folk that kill them. These are pilot whales which are not thought to be endangered. Ironically these animals, along with large tuna are going to be less attractive as food because they have significant amounts of mercury in them. There are ongoing investigations relating to the health effects of consuming too much whale meat in the Faeroes. The truth is, as he points out later, that these events are pretty minimal in the grand scheme of things – maybe a 1000 dolphins a year in Japan. More cetaceans are killed as bycatch in other fisheries.
He states that Pacific Bluefin tuna are at 3% of their original stock levels and that they are endangered. They are neither. Current stock levels are 4.5% of the biomass you would expect if fishing effort was zero and it is rebuilding so that the stock has improved to vulnerable status. Still not fantastic but it illustrates that the relatively young science of fisheries management is having a positive impact (the Western and Central Pacific Fisheries Commission was only established in 2004). Many stocks of tuna are in relatively good condition and international management measures are improving all the time. Satellite based monitoring systems are likely to improve management further.
He states that shark populations have dropped to 1% of their origin. Again, this is needless exaggeration. It is true that Oceanic sharks are thought to have declined by ~70%. For many shark populations we just don’t know, others such as the Blue shark appear to be at equilibrium or in decent condition. He suggests that 90% of large fish have disappeared. This is just wrong. The figure is based on a paper that used catch data (which are not a good measure of population size) from a Japanese longline fishery. He made a statement about a 99% decline in cod. I can’t work out exactly where that came from (there have been numerous nonsensical stories about cod over the last 20 years including one about there only being 100 cod left in the North Sea) but it is patently not true, overall Atlantic cod are increasing in number. Stocks are doing poorly in the south of their range and in the Western Atlantic – this is likely to do with warming water impacting on reproduction and survival. Shark finning gets a mention too – I find this practice abhorrent, it is wasteful. Shark fisheries require particularly careful management due to long generation time and low reproductive rates.
He repeats the completely discredited assertion from 2006 that suggested that by 2048 there would be no fish left in the sea and we would be eating jellyfish. The original authors of the paper no longer stand by that assertion. It’s nonsense. There is a suggestion that large scale extraction of fish isn’t sustainable. This is just rubbish. The best managed fisheries, with robust data collection, good science and observer coverage are the large scale fisheries. These also happen to be the best fisheries when you consider CO2. Large and efficient purse seiners use less CO2 per kg landed than those romantic wee boats that you find in rural villages.
“We can’t catch fish because we don’t know where to draw the line”
This made me laugh out loud. There is uncertainty in fisheries management (along with most other aspects of life) and I’d argue we do know where to draw the line. There are instances where we don’t get it right but these are becoming fewer. In the face of an exponentially increasing human population, fisheries management has done pretty well to stabilize fishing effort in most fisheries. According to the FAO, 67% of fisheries worldwide are now thought to be managed sustainably.
I agreed with much of the section on aquaculture although I think salmon farmers have got a bit better at not feeding fish to fish. Open pen salmon farming is an awful practice and I try to avoid eating farmed salmon. Open pen marine aquaculture is not the answer. Wild fish are a much healthier food choice and are a renewable resource.
If people can’t eat fish they will turn to other sources of protein. This is discussed in relation to the exploitation of seas around Africa where legal EU boats and illegal fishery pirates are overfishing stocks that local artisanal fishers depend on. He claims that in the absence of fish people turn to bush meat and then links that to Ebola. I’d like to see evidence linking these but it is true that if people cant eat fish they will eat other animal protein. People will not turn vegan because they can’t access fish. If they did that would bring its own environmental concerns. I’d argue that fish are a healthier source of protein and their consumption is less damaging to the planet. The environmental costs of many terrestrial sources of protein in terms of CO2 and Biodiversity loss are much higher than most fisheries. George Monbiot suggested that the only way to save life in the oceans is to stop eating fish. He suggests that fishing is the main issue threatening the integrity of the oceans. This is patently nonsense. The proportion of threatened fish species is the lowest of any group or animals.
Fisheries management has generally been an overwhelming success. In the face of an exponentially growing population landings from marine stocks have plateaued. They have plateaued because of stronger fisheries management and we continue to improve. Obviously there are issues, as there are with agriculture, big pharma, transport and social inequality.

To me the biggest problem in fisheries (well everything really) is inequality. Rich nations develop robust management systems but still want to eat cheap fish. They therefore import fish from countries with weaker management systems – for example Australia with its robust spatial management imports 60-70% of its fish from human consumption from Thailand, Vietnam (and New Zealand). The rich nations export or offshore their environmental issues elsewhere – this isn’t just a problem in fisheries.
Inequality rears its most ugly head in relation to poor labour practices in some fisheries. There are parts of the world where this is an issue and it is important to keep up pressure on government and supermarkets to end this practice. Twenty years ago I was an observer on a longliner around South Georgia in the South Atlantic. The Namibian crew on the boat were paid US$25 a week for a 7-day week. The sister ship to mine sank with many crew losing their lives – the observer on that boat was a hero and wrote a book about the experience. I have been picking away at the issue since then. It was an example of marine aprtheid where all the white officers were from the wealthy north and the black crew were from poverty backgrounds in rural Namibia. Poor labour practices mostly happen in Asia and around Africa but we also have a two tier system in the UK and Europe with some boats hiring migrant labour at 50% of the cost of local workers. But while these are issues of concern and grab headlines, they are not in every fishery by any stretch of the imagination.
This is a disappointing documentary, it’s more about the narcissism of a privileged young white boy talking about things that anyone with a smidgeon of interest in marine conservation can tell you are problematic – Japanese whalers, shark finning, plastic pollution, open pen salmon farming, inequality, tied together with a tissue if falsehoods, exaggeration and nonsense. There is no “big reveal” here. By breaking the law in Thailand and interviewing without a permit he may have put some poor guy at risk – someone who could very well be dead or imprisoned now. He interviewed a social scientist who really is trying to help make changes – without informing her of the direction he was taking or what the film was for. These are worryingly unethical behaviours and I’d be surprised if @netflix were happy with it. He picked on soft targets, folk trying to make a difference in a complex world and I think probably selectively edited the interviews to try and show the interviewees in a bad light. This guy isn’t an environmental hero.
If you want to keep up with the real science around fisheries and people who really are trying to make a difference, I recommend bookmarking @TrevorABranch pages of all time must read and annual must read papers. In putting this article together, I’ve leaned heavily on the https://sustainablefisheries-uw.org/ library (@SustainFishUW). The site has an interesting article about how misinformation gets into the public understanding of fisheries.
If you have read this article and are concerned about the environment, it should just be a starting point. Read more, inform yourself, take nothing at face value, listen carefully to opposing viewpoints, be ready to change your mind when faced with good evidence. You won’t learn much living in an echo-chamber.
If there are any errors in this piece – please let me know, give me evidence and I’ll correct them.
If you are a twitterer see comments by @BlahaFrancisco, @Taotaotasi, @Jack_IM9, @BD_Stew, @JamesBellOcean and @SeafloorScience