Question asked by Pierre on June 7th.
Your question concerns the veracity of the information and figures put forward in the Netflix documentary Seaspiracy, very dependent against industrial fishing, released in March. Director Ali Tabrizi paints a particularly dark picture of the state of our fishery resources and does not hesitate to accuse environmental protection associations as well as governments. The film, which uses thriller codes, seeks to convince the viewer to the detriment – sometimes – of the scientific method. While a lot of the data put forward is real, others are thus erroneous or dated.
Seaspiracy intends to warn about the dangers of fishing activity, from the ecological consequences, such as the case of the seabed scraped by trawls, to the consequences for humans. We thus learn, in one of the film’s most striking passages, that many Thai shrimp fishing boats use foreign migrants for their labor, even if it means transforming them into real slaves. The documentary also reviews, with supporting figures, the problems of bycatch (10,000 dolphins found on the French coasts each year according to the Pelagis observatory), salmon aquaculture in Scotland (more than 30% of specimens die before being fished) or the concern of overly lax labels.
Still, many voices among scientists have spoken out against Seaspiracy. “With its propagandist vision and its fanciful figures, the documentary even had the rare consequence of bringing together pro-fishing and pro-environmental conservation scientists”, sums it up for Checknews Joachim Claudet, researcher specializing in the impact of human activities on the ocean at the CNRS. Such as Ray Hilborn and Daniel Pauly, figureheads of each of these currents. To see more clearly, Checknews reviews the documentary’s most problematic claims. Solicited by us, neither the director nor the producer of the film responded.
There will be no more fish in the oceans by 2048
Seaspiracy refers to a study by Boris Worm published in 2006 in the journal Science. Except that, as pointed out Telerama, it was a projection in the event that uncontrolled overfishing continued, which was not necessarily the case. “Most of the data are catastrophic figures to test different scenarios, they don’t make sense if they are taken out of context”, confirms Joachim Claudet. Three years later, in 2009, Worm went back on his own predictions and published a text already noting “Individual stock replenishments” of fish. A 2020 study points in the same direction, indicating that a large majority of species are seeing their populations increase due to the tightening of restrictions.
Each year, of all the fish caught in the world, 40% are bycatch
From turtles to dolphins to sea otters, animals sometimes threatened with extinction are mistakenly caught in the nets of sailors before being rejected, often in a poor state. If the documentary puts the figure at 40%, they are actually estimated at 10%, according to a 2017 study. “The vast majority of rejections […] were carried out by industrial fisheries […], while artisanal fisheries have contributed very little to global discards ”, specifies in this article the research group of the University of British Columbia. The 40% highlighted in the documentary concern the work of various associative activists, who have added in their calculations the by-catches and the catches made in an unsustainable way, by the use of an illegal net for example or by violation of quotas when these exist. The calculation nevertheless corresponds to a reality since the rejected specimens do not necessarily survive their capture.
38% of the world’s mangroves have been destroyed by shrimp farming
The director affirms through the voice of journalist and environmental activist George Monbiot that 38% of coastal marshes (mangroves), which are present in 120 countries, have been destroyed because of shrimp farming. The reference work, which probably serves as a source for Monbiot, gives the figure of 35% of mangroves lost (that of 38% corresponding to the United States alone). Moreover, if this study does point the finger at the responsibility of shrimp farming in the destruction of the mangrove – “Shrimp cultivation is by far the main cause” can we read – it also lists the weight of other types of farming in this disaster: fish and shrimp farms together are half responsible for the loss of these natural environments (52%). Finally, more generally, these data are dated since they were recorded … before 2000.
Hammerhead sharks are on the verge of extinction
An alarmist graphic, pointing to the almost complete disappearance of four species of sharks since 1970, also questions. The diagram, which does not cite its source, contradicts figures from a January 2021 study published in the very serious British scientific journal Nature, reference in the matter. If the latter notes a collapse of 71% of the general shark population since 1970 due to the intensification of industrial fishing, this is not the case for the common hammerhead shark, for example. (smooth hammerhead), which is an exception. When the documentary claims their population has declined 86% since 1970, Nature estimates that their number would have on the contrary increased… by 29%. According to the same study, the scalloped hammerhead shark (scalloped hammerhead) has dropped drastically, around 77%, but not as much as the documentary announces, which mentions a drop of 99%.
Fishing litter accounts for 46% of the North Pacific litter vortex
Journalist George Monbiot asserts that waste from fishing (nets and buoys in particular) represents “More than 46% of the plastic floating in the North Pacific vortex”, an area of 1.6 million square kilometers. This percentage does exist. It is from the largest study on the subject, The Great Pacific Garbage Patch, (GPGP, another name for the vortex) dating from 2018, which indicates that fishing nets represent “46% of the mass of the GPGP”.
If it is true, this figure deserves a perspective. Indeed, Seaspiracy does not mention the presence in the vortex of microplastics, much lighter but much more numerous in terms of floating debris (94% of the pieces spotted on the surface), such as straws and bags. Some of them stagnate on the surface, others disintegrate and fall to the ocean floor, where they become particularly dangerous for marine life.
250,000 turtles are killed each year in the United States
On this subject, the documentary uses the figure of 250,000, proposed by researchers in 2004. While it could have used that established by the same specialists in 2011: thanks to the application of drastic regulations, the number of animals killed had fallen, according to minimum estimates, to 4,600. That is a drop of 94%, even if the researchers recognize a percentage certainly overestimated for lack of observers. A more recent study from 2017 concludes that there is an increase “Significant” populations in certain regions since 2010, thanks to new fishing devices: the Turtle Excluder Device (TED), which frees the turtles thanks to a grid installed in the narrow part of a trawl.
This article was produced as part of a partnership with the CFPJ for the application journal for promotion 56.