Oceanic Whitetip Sharks: Swimming Toward Extinction

Of the world’s large shark species, the oceanic whitetip (Carcharhinus longimanus) is one of the most striking. It takes its common name from its distinctive long, white-tipped, rounded fins. The oceanic whitetip is a pelagic species, meaning it lives offshore in deep waters, although it tends to remain close to the surface. It is highly migratory and widely distributed in the world’s tropical and subtropical oceans.ⁱ 

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Thomas Ehrensperger/WikiCommons (CC BY-SA 3.0)

Like other large sharks, oceanic whitetips are top predators. They primarily eat bony fish such as tuna and mackerel and cephalopods like squid, but have been known to eat sportfish, sea birds, other sharks and rays, marine mammals, and even garbage.ⁱⁱ  Because their pelagic habitat is resource poor, prey items can be few and far between, so they have evolved to be opportunistic eaters.

Oceanic whitetips have a fearsome reputation as an extremely dangerous shark.ⁱⁱⁱ  They are known to have attacked survivors of plane crashes and shipwrecks as well as surfers and snorkelers. But oceanic whitetips are far more likely to be killed by humans than they are to kill humans. The International Shark Attack File has tracked shark attacks around the world since 1958. The data, although incomplete, show that an average of 70 unprovoked shark attacks (by all shark species) occur each year, resulting in about five fatalities.^iv

Humans, on the other hand, kill tens of millions of sharks every year, through both targeted fishing efforts and incidental bycatch in fishing gear targeting other fish species. Fishing continues to kill northward of eighty million sharks annually, even after two decades of increased regulation.^v  According to the International Union for the Conservation of Nature Red List, overfishing has resulted in one-third of all shark and ray species worldwide being threatened with extinction.^vi  

The Red List categorizes the oceanic whitetip as “Critically Endangered,” the second-to-last stop before extinction.^vii  Because of its preference for warm, tropical waters and its tendency to remain near the surface, the species is frequently caught and killed accidentally by fisheries throughout its range in gears such as longlines, purse seines, and gillnets.^viii Because their distinctive fins are especially prized in the international shark fin trade,^ix  fishermen often cut them off and sell them. 

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Michael Aston (CC BY-NC 2.0)

Humans are killing the species far faster than it can reproduce. A slow-growing, long-lived apex predator, the oceanic whitetip does not reach maturity until between six and nine years old and then only gives birth every other year after a lengthy gestation of 10-12 months to an average of six pups.^x  The oceanic whitetip was once among the most common sharks in tropical waters. The Red List assessment, however, calculates that it has suffered a median global population reduction of 98 to 100% across six different ocean regions over 60 years.^xi 

Defenders has long focused on shark conservation both within the U.S. and around the world. On the international front, Defenders staff worked for years to get the oceanic whitetip and other shark species listed under the Convention on International Trade in Endangered Species (CITES) to help protect them from international trade pressures. This hard work paid off in 2013 when the Conference of the Parties added the species to CITES Appendix II. On the domestic front, Defenders attorneys petitioned NOAA Fisheries in 2015 to list the oceanic whitetip as endangered or threatened under the Endangered Species Act (ESA). In 2018, NOAA Fisheries issued a rule listing the species as threatened throughout its range,^xii meaning that although it is not yet in danger of extinction, it is likely to become endangered in the foreseeable future.^xiii  

Unfortunately, the oceanic whitetip’s survival and recovery prospects remain far from certain. Despite recent conservation successes such as the Shark Fin Sales Elimination Act, a federal law enacted in 2022 to establish a nationwide trade ban on shark fins,^xiv fisheries bycatch and trade in the species’ fins persist worldwide and its population declines continue. 
The oceanic whitetip shark’s ongoing decline despite its ESA listing illustrates a significant weakness in NOAA Fisheries’ approach to protecting threatened species in the U.S. and around the world, because the agency rarely brings the full force of the ESA to bear.

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Alexander Vasenin/WikiCommons (CC BY-SA 4.0)

Section 9(a)(1) of the ESA contains powerful protections for listed fish and wildlife species, including prohibitions on the unauthorized import, export, interstate and foreign commerce, and, most broadly, “take” in the United States (including its territorial sea) or on the high seas.^xv In turn, “take” as defined by statute to include harassing, harming, pursuing, hunting, shooting, wounding, killing, trapping, or capturing—and even attempting to engage in such conduct.^xvi  Importantly, these prohibitions apply to “any person” subject to U.S. jurisdiction,^xvii where a “person” can be an individual but also a corporation or other private entity, an employee of any federal, state, or local agency or the agency itself, or a foreign government.^xviii Otherwise-prohibited actions can be authorized through processes that help ensure they will not interfere with the species’ survival and recovery.^xix 

When NOAA Fisheries lists wildlife species as endangered, all section 9(a)(1) protections apply automatically. When it lists wildlife species as threatened, however, none of these protections apply unless it also issues an ESA section 4(d) species-specific rule.^xx This represents a significant difference in how NOAA Fisheries and the U.S. Fish and Wildlife Service (FWS) protect threatened species. As my colleagues recently described, the Biden administration “took a big step in the right direction for species protection by reinstating what’s often called the ‘blanket 4(d) rule’” for FWS, to ensure threatened species get all section 9 protections by default, unless FWS issues a more limited species-specific rule.^xxi  

Unlike FWS, NOAA Fisheries has never had a blanket 4(d) rule and does not automatically confer section 9(a)(1) protections at listing. Although NOAA Fisheries-listed threatened species like the oceanic whitetip receive important ESA section 7 protections that require the agency to protect the species from undue harm when authorizing U.S. fisheries, they aren’t protected by the full power of the ESA unless NOAA Fisheries takes explicit action. Out of the 85 threatened species under NOAA Fisheries’ jurisdiction,^xxii only a handful have ever gotten section 9 protections via 4(d) rules.^xxiii In failing to follow the ESA’s mandate to issue protective regulations that are “necessary and advisable” for a threatened species’ conservation,^xxiv i.e., survival and full recovery,^xxv at the time of listing, NOAA Fisheries is missing an important opportunity to prevent threatened species from declining further. 

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Michael Aston (CC BY-NC 2.0)

NOAA Fisheries recently started the process of filling this gap for oceanic whitetips by issuing a proposed section 4(d) rule to give the oceanic whitetip sharks additional statutory protections under section 9(a)(1). If finalized, the rule will prohibit import, export, take, transport, and trade in the oceanic whitetip shark (or any of its parts).^xxvi These protections would mean that no one can engage in prohibited activities without a permit. 

There has already been a six-year gap between the agency’s listing the oceanic whitetip as threatened and proposing a 4(d) rule, and we do not expect to see a final decision on the proposal before 2025. While we support NOAA Fisheries’ proposal, NOAA Fisheries needs to do better by threatened species like the oceanic whitetip shark. NOAA Fisheries should bring the full power of the ESA to bear when it lists threatened species, to halt their declines and put them on the road to recovery. 

ⁱNOAA Fisheries, “Oceanic Whitetip Shark,” https://www.fisheries.noaa.gov/species/oceanic-whitetip-shark (last updated July 10, 2024).
ⁱⁱId.
ⁱⁱⁱFlorida Museum, “Oceanic Whitetip Shark,” https://www.floridamuseum.ufl.edu/discover-fish/species-profiles/carcharhinus-longimanus/ (last revised 2018).
^ivFlorida Museum, International Shark Attack File, “How to Avoid a Shark Attack,” https://www.floridamuseum.ufl.edu/shark-attacks/reduce-risk/how-to-avoid-a-shark-attack/ (last visited Aug. 29, 2024).
^vWorm, Boris et al. Global shark fishing mortality still rising despite widespread regulatory change. Science Vol. 383, No. 6699, pp. 225–30. Jan. 11, 2024. https://doi.org/10.1126/science.adf8984
^viDulvy, Nichols K. et al. Overfishing drives over one-third of all sharks and rays toward a global extinction crisis. Current Biology Vol. 31, Issue 21, pp. 4773–87. Nov. 8, 2021. https://doi.org/10.1016/j.cub.2021.08.062
^viiIUCN Red List, Oceanic Whitetip Shark, https://www.iucnredlist.org/ja/species/39374/2911619 (last visited Aug. 29, 2024).
^viiihttps://www.fisheries.noaa.gov/species/oceanic-whitetip-shark
^ixId.   
^xhttps://www.fisheries.noaa.gov/species/oceanic-whitetip-shark
^xihttps://www.iucnredlist.org/species/39374/2911619
^xiiNOAA Fisheries, Listing the Oceanic Whitetip Shark as Threatened Under the Endangered Species Act, 83 Fed. Reg. 4153 (Jan. 30, 2018).
^xiii16 U.S.C. § 1532(6), (20) (defining “endangered” and “threatened” species).
^xivNational Defense Authorization Act, FY2023, 117 H.R. 7776, Pub. L. 117-263 (Dec. 23, 2022), § 5946
^xv16 U.S.C. § 1538(a)(1).
^xvi16 U.S.C. § 1532(19).
^xvii16 U.S.C. § 1539(a)(1).
^xviii16 U.S.C. § 1532(13).
^xix16 U.S.C. §§ 1536(b)(4), 1539.
^xx16 U.S.C. § 1533(d).
^xxiU.S. Fish and Wildlife Service, Regulations Pertaining to Endangered and Threatened Wildlife and Plants, 89 Fed. Reg. 23,919 (Apr. 5, 2024).
^xxiiNOAA Fisheries, Species Directory, ESA Threatened & Endangered, https://www.fisheries.noaa.gov/species-directory/threatened-endangered (last visited Aug. 29, 2024). 
^xxiiiSee 50 C.F.R. Part 223.
^xxiv16 U.S.C. § 1533(d).
^xxv16 U.S.C. § 1532(3) (defining conservation to mean the use of all methods and procedures necessary to bring listed species to the point at which the ESA’s protections are no longer necessary).
^xxviNOAA Fisheries, Protective Regulations for the Oceanic Whitetip Shark (Carcharhinus longimanus), 89 Fed. Reg. 41,917 (May 14, 2024).