Debunking Shiffman's Latest: "The role and value of science in shark conservation advocacy”

Although written in an authoritative style, Shiffman et al.’s paper “The role and value of science in shark conservation advocacy” (2021) contains a number of lethal flaws which invalidate it. In particular, it claims that the survey on which it is based shows that conservationists favour bans over sustainable shark fishing more than scientists. But in fact the survey of scientists cited (Shiffman & Hammerschlag 2016 b) showed that 63% of scientists favour bans while this paper states that only 41% of conservationists do. This mismatch between the findings of the two surveys and the claims of these authors invalidates much of what they state. Their survey also establishes that conservationists do in fact base their published information on scientific papers, rather than public belief or moral considerations, so the authors’ conclusion is seriously in error.

Leaving aside for the moment the reason why alleged “shark scientists” would spend the time it took to write this attack on people who value biodiversity and are concerned about the current status of sharks, this paper is based on a mickey mouse questionnaire which fails to take into account the nuances in a complex subject, telescoping it into two political positions. It would have been tossed in the bin if submitted in any philosophy class in a learning institute. That it could have been published at all strongly supports our conviction that 'sustainable shark fishing' is not being defended against unsustainable shark fishing, but against effective shark protection from the forces that are driving them to extinction.

The authors focus only on the conservationists’ attitude to the subjects of the two bills now being considered as future legislation in the USA, revealing an essentially political stance. The Sustainable Shark Fisheries and Trade Act of 2018 is the shark fishing industry’s supposed solution to shark depletion (Gehan 2016), while The Shark Fin Sales Elimination Act of 2017, which would effectively remove the USA from the shark fin trade, is the choice of those who want effective protection for sharks. The cited article’s slanted presentation suggests, therefore, that it is political in nature, and written to grant scientific credibility to the erroneous idea that the shark fin trade is sustainable (see their Fig. 5). Indeed, Shiffman’s rhetorical arguments tend to echo, often almost word for word, those of the shark fishing industry spokesmen from the Sustainable Shark Alliance (Shiffman & Hueter 2017, Gehan 2016).

The only evidence offered to establish the existence of sustainable commercial shark fisheries is Simpfendorfer and Dulvy’s 2017 paper “Bright spots of sustainable shark fishing,” a work that was already in error two years after it was published. It claimed, for example, that the mako shark fisheries in the North and South Atlantic serving the shark fin trade could be sustainable with management. But at the same time, scientists from the International Commission for the Conservation of Atlantic Tunas (ICCAT) found that the status of the mako shark was so dire that even if all fishing was stopped immediately, its numbers would continue to decline for the next fifteen years. With a population collapse imminent, there was a probability of only about 50% that the stock would be rebuilt by 2045, and the probability that it would be rebuilt would not exceed 70% until 2070, 50 years from now (ICCAT 2019).

Commercial fishing of the blue shark was also promoted by Simpfendorfer and Dulvy (2017) as being potentially sustainable in spite of a paucity of data. They used MSY to make their claim, but MSY is based on actual landings so it is completely inapplicable to a species which is mostly discarded (Campana 2016). The blue shark is also considered to be overfished in the North Atlantic (ICCAT 2020).

The sharks in the North Atlantic are managed by ICCAT, which represents 48 contracting nations and groups, including the European Union. Member nations provide data – of highly variable quality – for their fisheries, and there are several major fishing nations working the North Atlantic that are not party to ICCAT and provide no shark catch data to anyone. It is estimated that only a quarter of the sharks killed there are reported, and that illegal finning is rampant (Campana 2016). No scientific paper brings any evidence as to how shark fishing could possibly be managed sustainably under such circumstances. Indeed, it has been scientifically established that it is impossible to manage the commons (Agrawal 2001), especially the high seas. These authors should be aware of that.

The North Atlantic, right in the heart of the “civilized” world, should be the very epitome of excellent fishing management and sustainable shark fishing. The truth clearly is far from that, and the situation is even worse in the Pacific and Indian oceans. Yet Shiffman et al. write:

“Results show that in general, the environmental advocates who most strongly supported bans on fisheries and trade were the least familiar with the current state of scientific knowledge on sustainable shark fisheries.”

On the contrary, it appears to be Shiffman et al. who are out of touch with the current state of scientific knowledge on sustainable shark fisheries. They also cite Walker (1998) as evidence of their existence, but his paper actually questions whether sustainability in commercial shark fishing can be realized and focuses on the difficulties of accomplishing it. Further, it was written before the shocking results of the shark fin trade became evident and so is completely irrelevant here. The only other paper which the authors cite as evidence that sustainable shark fisheries exist is Shiffman’s own paper (Shiffman & Hueter 2017), which claimed that they exist all over the world, but provided no evidence whatsoever that they actually do. It was indeed thoroughly rebutted (Porcher et al. 2019).

Contrary to what the authors state, there is much evidence which throws into question the idea that long-term sustainable commercial shark fisheries are possible, particularly in the face of the secretive and largely criminal shark fin trade (Porcher & Darvell 2021, submitted). Traditionally, the shark and skate fisheries that have been managed sustainably were those few, mostly in the USA and Australia, that took the animals for meat (Dent & Clarke 2015). But this present paper fails to differentiate between those and the current hunt to supply the shark fin trade, which now involves industrial fisheries from nations around the globe.

That is all the scientific evidence that these authors can find to support their statement, made about four times throughout the paper, that “there is no scientific doubt that sustainable shark fisheries exist”. However, there are plenty of papers that document the loss of sharks as a result of seven decades of industrial fishing, and with the added scourge of the shark fin trade, increasing numbers are listed by IUCN as being threatened with extinction. This makes it clear that whoever is saying that sharks are being sustainably fished is claiming that black is white. That this claim can seriously be made and published indicates a monumental level of cognitive dissonance not only in shark fisheries, but in ‘shark science.’

This paper’s theme of promoting shark fishing while belittling conservationists is a common one in Shiffman’s writings (Shiffman & Hammerschlag 2014, 2016a,b). The claim that the public is concerned about sharks because they “can be ecologically important” implies that sharks may or may not be of much ecological importance, and minimizes an important concern with regards to the current and ongoing extent of shark depletion.

All relevant ecological studies have found that, as top and middle predators, sharks are among the most strongly interacting animals in the food chain, with the result that the extreme disruption wrought by more than seven decades of industrial shark removal has caused major, cascading biodiversity shifts throughout the originally complex and diverse aquatic ecosystems which evolved during the previous 500 million years (e.g. Okey et al. 2004; Ward & Myers 2005; Myers et al. 2007; Heithaus et al. 2007, 2008; Ferretti et al. 2010).

There is also the claim that the public is concerned about sharks because they “are a popular encounter for scuba divers and other marine tourists.” Terming divers “marine tourists” disparages a major force behind shark conservation efforts. A large proportion of divers dive locally and regularly, knowing their area well. They have personally witnessed the disappearance of sharks from the oceans and coasts the way the buffalo vanished from the plains of North America during the 1800s. Therefore, they have always been at the forefront of shark conservation efforts. This statement wholly misrepresents the reasons why so many members of the public are concerned about sharks.

The results of the survey on which this paper is based show that two thirds of NGO employees read scientific papers regularly and more than half have published scientific papers. This was found even though the authors deliberately excluded scientific researchers working in conservation from the survey, which is an altogether startling bias. The data show that NGOs use scientific and not moral reasons for their arguments for shark protection, so the conclusion should have been that NGO employees working on shark conservation are, with few exceptions, scientifically-informed, rather than the contrary.

To anyone who is aware of the actual state of shark depletion, it is extremely worrying to see this sort of pseudo-philosophical, pro-shark fishing propaganda neglecting biological facts, yet being published as if it were science. 

 

References

Agrawal A (2001) Common Property Institutions and Sustainable Governance of Resources. World Development 10(29): 1649-1672.

Campana S. E. (2016) Transboundary movements, unmonitored fishing mortality, and ineffective international fisheries management pose risks for pelagic sharks in the Northwest Atlantic. Can. J. Fish. Aquat. Sci. 73:1599–1607.

Dent F, Clarke SC (2015) State of the Global Market for Shark Products. United Nations Food and Agriculture Organization Fisheries and Aquaculture. (Technical Paper 590)

Ferretti F, Worm B, Britten GL, Heithaus MR, Lotze HK (2010) Patterns and ecosystem consequences of shark declines in the ocean. Ecology Letters. 13(8):1055–1071 doi.org/0.1111/j.1461-0248.2010.01489.x

Gehan, S. M. (2019) Testimony of the Sustainable Shark Alliance Before the House Subcommittee on Water, Oceans, and Wildlife March 26, 2019 naturalresources.house.gov/imo/media/doc/Gehan%20Testimony%20WOW%20Leg%20Hrg%2003.26.19.pdf Accessed 14 April 2020

Heithaus MR, Frid A, Wirsing AJ, Dill LM, Fourqurean JW, Burkholder D, Thomson J, Bejder, L (2007) State-dependent risk-taking by green sea turtles mediates top-down effects of tiger shark intimidation in a marine ecosystem. Journal of Animal Ecology 6:837-844 doi.org/10.1111/j.1365-2656.2007.01260.x

Heithaus MR, Frid A, Wirsing AJ, Worm B (2008) Predicting ecological consequences of marine top predator declines. Trends in Ecology & Evolution. 23(4):202-210.

ICCAT (2019) International Commission for the Conservation of Atlantic Tunas Report of the Standing Committee on Research and Statistics (SCRS) Madrid, Spain, 30 September to 4 October 2019 www.iccat.int/Documents/Meetings/Docs/2019/REPORTS/2019_SCRS_ENG.pdf Accessed 22 April 2020

ICCAT SCRS (2020) Advice to the Commission, English version Madrid, Spain 2020 https://www.iccat.int/Documents/SCRS/SCRS_2020_Advice_ENG.pdf Accessed 18 September 2021

Myers RA, Baum JK, Shepherd TD, Powers SP, Peterson CH (2007) Cascading Effects of the Loss of Apex Predatory Sharks from a Coastal Ocean Science. 423(6937):280-3 doi.org/10.1126/science.1138657

Okey TA, Banks S, Born AF, Bustamante RH, Calvopiña M, Edgar GJ, Espinoza E José MiguelFariña J, Garske LE, Reck GK Salazar S, Shepherd S, Toral-Granda V, Wallem P (2004) A trophic model of a Galápagos subtidal rocky reef for evaluating fisheries and conservation strategies. Ecol. Model.172:383–401

Porcher I. F., Darvell B. W., Cuny G (2019) Response to “A United States shark fin ban would undermine sustainable shark fisheries” D.S. Shiffman & R.E. Hueter, Marine Policy 85 (2017) 138-140. Marine Policy. 104:85-89 doi.org/10.1016/j.marpol.2019.02.058

Porcher, I. F. & Darvell B. W. (2021) Shark Conservation – Analysis and Synthesis. Preprints 2021, 2021020145 doi: 10.20944/preprints202102.0145.v3

Simpfendorfer, C. A. & Dulvy, N. K. Bright spots of sustainable shark fishing. Curr. Biol.27(3), R97–R98 (2017).

Shiffman D. S. & Hammerschlag N. (2014) An Assessment of the Scale, Practices, and Conservation Implications of Florida's Charter Boat–Based Recreational Shark Fishery, Fisheries, 39:9, 395-407, DOI: 10.1080/03632415.2014.941439

Shiffman, D. S. & Hammerschlag, N. Shark conservation and management policy: A review and primer for non-specialists. Anim. Conserv.19(5), 401–412 (2016).

Shiffman, D. S. & Hammerschlag, N. Preferred conservation policies of shark researchers. Conserv. Biol.30(4), 805–815 (2016).

Shiffman D. S., Hueter R.E. (2017) A United States shark fin ban would undermine sustainable shark fisheries. Mar. Pol. 85:138–140.

Shiffman D. S., Macdonald C. C., Wallace S. S., & Dulvy N. K. The role and value of science in shark conservation advocacy 1Vol.:(0123456789)Scientific Reports | (2021) 11:16626 | https://doi.org/10.1038/s41598-021-96020-4www.nature.com/scientificreports

Ward P, Myers RA (2005) Shifts in open-ocean fish communities coinciding with the commencement of commercial fishing. Ecology 86:835–847.