Today is Endangered Species Day... The day activists and the public all over the world come to together to learn and take action for Endangered species. Whilst there might be cuter and more charismatic threatened animals, like giant pandas or dolphins, it is vital that we spread the message about how seriously at risk all sharks and rays are. Often described as one of the most threatened groups of animals on the planet, we are at very real risk of losing many of these precious animals forever. So which sharks and rays are threatened? Why are they threatened? And most importantly, what can be done to turn the tide?
What Does Endangered Mean?
The International Union of the Conservation of Nature is responsible for assessing populations of wild plants, animals and fungi to determine whether they are declining, increasing or remaining stable. This organisation then produces the Red list of Threatened Species, which gives detail about every species that has been assessed to date and whether they have been flagged for concern.
The Red List sorts species into nine different categories that describes the status of their populations in the wild: Not Evaluated, Data Deficient, Least Concern, Near Threatened, Vulnerable, Endangered, Critically Endangered, Extinct in the Wild and Extinct. Species that are flagged as Vulnerable, Endangered or, worst of all, critically Endangered are considered to be "threatened" with extinction in the wild.
To flag a species as threatened involves a very complex science-based assessment by many experts in the field. Scientists in the Shark Specialist Group (IUCN SSG), for instance, are often involved in analysing the wild populations of sharks, skates and rays (IUCN, 2020).
This team of experts assesses the species' current population sizes on both global and regional scales, learns what threats they face, and determines whether they are declining. They also consider how likely the species is to be able to rebound from these declines by considering how many offspring they can have and how often the can breed, how long it takes them to reach maturity and how long they live (IUCN, 2020; IUCN, 2023). If you would like to get more detail about this process, you can read the assessment criteria the IUCN uses, which are all open access.
The IUCN Red List is regularly updated, with scientists working constantly to assess more species and continually reassessing threatened species to see whether they are improving, or whether their populations are declining even further. The Red List is then formally updated twice a year to publish all these (re)assessments to the public and the scientific community (IUCN, 2020; IUCN, 2023).
How Many Sharks are Endangered?
Sharks, skates and rays are so closely related that we often talk about them as one group - the "elasmobranchs". There are over 1200 different species: some 530+ sharks and 800+ "batoids" (flat sharks), including rays, skates, guitarfishes, wedgefishes and sawfishes (Ebert et al, 2021).
In 2020 the IUCN made headlines by announcing that their regular update of the Red List had reclassified 300 species of sharks, batoids and their close relatives the chimaeras, as Endangered. This included adding many species to the Red List that had not been assessed before, but also involved upgrading many species that were already considered at risk to much more serious risk categories. This meant that about 1/4 of all species of sharks, skates, rays and chimaeras are now considered to be "threatened" according to the IUCN. Sadly, the IUCN also concluded that several species of sharks and rays should already be considered extinct, including the Pondicherry shark (Carcharhinus hemiodon). Scientists now consider sharks and their relatives to be one of the most seriously threatened group of animals on the planet (IUCN, 2020; IUCN, 2023). See Will 300+ Species of Sharks Go Extinct? to learn more.
“ Sharks and their relatives are facing an alarmingly elevated risk of extinction ”
- Dr Nick Dulvy, IUCN SSG Co-Chair
Which Sharks are Threatened with Extinction?
Not all species of sharks, skates and rays are equally threatened with extinction. Each species experiences unique threats, and every population grows and shrinks at different rates. Within the sharks, there are specific groups (known as "taxonomic groups", which are made up of closely related species) that are especially threatened. Two groups of sharks are considered to be at the most imminent risk of extinction in the wild: the angel sharks (Family Squatinidae) and hammerheads (Family Sphyrnidae) are seriously in trouble and they now have a disproportionate number of their members flagged by the IUCN (Dulvy et al, 2014; Gallagher et al, 2014; IUCN, 2020; IUCN, 2023). To learn more you can check out Hammer Time.
But it is not just sharks that are at risk! Their skate and ray relatives (known collectively as "batoids") are also a major cause for concern! A plethora of batoids are threatened with extinction. In fact, some groups - such as Guitarfishes (Family Rhinobatidae) and wedgefishes (Family Rhinidae) - are far more threatened than sharks! Whatsmore, their close relatives the sawfishes (Family Pristidae) are thought to be one of the most threatened groups of animals in the world! (Dulvy et al, 2014; Kyne et al, 2019). To learn more, see The Rhino-Saws.
Why Are So Many Sharks and Rays Endangered?
There are many, many threats that sharks and their relatives face, mostly driven by human activities. Whilst the hazards vary depending on the species, the greatest threat generally comes from overfishing. When you look at threatened species of sharks and rays, overexploitation in fisheries is always a factor in their declines. These animals are fished, not only for their fins, but also for their meat, cartilage, liver oils, teeth and jaws. They are also the victim of bycatch in fisheries targeting other commercially valuable species (Ward-Paige et al, 2012). To learn more, check out A Fish Out of Water and If You Love Me, Let Me Go.
Sharks and rays are also often affected by habitat loss and degradation. This includes removing habitat for urbanisation and other forms of construction, and damaging habitats via alteration (dredging, mining, underwater construction etc.) and pollution (chemicals, litter, plastics etc.). This is especially true for species which live near to the coast or in freshwater systems, like rivers and lakes, where they are closer to human disturbances (Ward-Paige et al, 2012). Find out more at Getting Fresh.
Climate change is now also known to be having some impact on sharks and rays, with ocean acidification affecting their behaviour and their ability to breed, and increasing temperatures and ocean deoxygenation altering their natural distibutions. As this is such a new field of study, there is still a lot more to learn about the impact these issues may have on threatened sharks and rays (Ward-Paige et al, 2012; IUCN, 2020; IUCN, 2023).
Can We Turn the Tide?
Listing a species as threatened on the IUCN Red List does not automatically mean that that species is offered any kind of protection. Instead, after the IUCN has flagged that a species is at risk, conservationists must then begin designing management plans and urging governments to implement legislation which can protect endangered species on regional and global scales (IUCN, 2023).
This takes an enormous amount of work, with multiple different non-profit organisations, advocacy groups, politicians, scientists and conservationists all coming together, to pressurise governments and global organisations to enforce new laws.
But it is certainly not hopeless! And we are getting there! Many varied species of sharks and rays are now the subject of different protective measures, in many different countries around the world. Some are even protected by agreements between multiple nations.
Shark lovers celebrated an especially big win after the Convention on International Trade in Endangered Species of Wild Fauna and Flora made history by voting in favour of groundbreaking restrictions to the international trade in shark products at COp19 in 2022. This legislation massively limited how products (including meat, fins, teeth etc.) from hammerheads (Family Sphyrnidae) and requiem sharks (Family Carcharhinidae) may be bought and sold on the international market. So steps are being taken and improvements are being made (CITES, 2022).
“Recovery of elasmobranchs is certainly possible but requires time and a combination of strong and dedicated management actions to be successful”
- Ward-Paige et al. (2012)
The question remains whether our efforts are going to effective or whether it is all too little too late. Only time will tell. But we must stay positive and keep trying! Sharks are vital to the health and welbeing of our oceans as a whole; balancing ecosystems and ensuring food security for millions of people around the world.
BUT we also have a moral obligation to do everything we can to undo the damage that we have done to them, because sharks and their relatives have just as much of a right to life as we do! Human beings have put an enormous amount of thought and effort into developing the technology that has allowed us to so-effectively decimate shark and ray populations in the wild, so if we can turn all that creativity and innovation into saving them, there is no limit to what we could achieve! It is my firm belief that we have it in us to make the changes and successfully turn the tide for endangered species of sharks and rays, we just have to put in the effort!
To stay up-to-date with shark and ray conservation you can follow the IUCN SSG on YouTube.
References
CITES (2022). Nineteenth meeting of the Conference of the Parties for the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CoP19) Summary Records. Access online.
Dulvy NK, Fowler SL, Musick JA, Cavanagh RD, Kyne PM, Harrison LR, Carlson JK, Davidson LNK, Fordham SV, Francis MP, Pollock CM, Simpfendorfer CA, Burgess GTH, Carpenter KE, Compagno LJV, Ebert DA, Gibson C, Heupel MR, Livingstone SR, Sanciangco JC, Stevens JD, Valenti S & White WT (2014). Extinction risk and conservation of the world’s sharks and rays. eLife , 3:e00590. Access online.
Dulvy NK, Davidson LHK, Kyne PM, Simpfendorfer CA, Harrison LR, Carlson JK & Fordham SV (2016). Ghosts of the coast: global extinction risk and conservation of sawfishes. Aquatic Conservation: Marine and Freshwater Ecosystems, 26, 134–153. Access online.
Ebert DA, Dando M& Fowler S (2021). Sharks of the World: A Complete Guide, Second Edition. Princeton University Press: UK. IBAN: 978-0-691-20599-1.
Gallagher AJ, Hammerschlag N, Shiffman DS & Giery ST (2014). Evolved for extinction: The cost and conservation implications of specialization in hammerhead sharks. BioScience, 64:7, 619-624. Access online.
IUCN (2020). International Union for the Conservation of Nature Red list of Threatened Species Report.
IUCN (2023). International Union for the Conservation of Nature Red list of Threatened Species. Access online.
Kyne PM, Jabado RW, Rigby CL, Dharmadi, Gore MA, Pollock CM, Herman KB, Cheok J, Ebert DA, Simpfendorfer CA & Dulvy NK (2019). The thin edge of the wedge: extremely high extinction risk in wedgefishes and giant guitarfishes. BioRxiv Preprint. Access online.
Ward-Paige CA, Keith DM, Worm B & Lotze HK (2012). Recovery potential and conservation options for elasmobranchs. Journal of Fish Biology, 80 , 1844–1869. Access online.
By Sophie A. Maycock for SharkSpeak
