{"id":685524,"date":"2026-03-27T12:46:17","date_gmt":"2026-03-27T12:46:17","guid":{"rendered":"https:\/\/www.europesays.com\/us\/685524\/"},"modified":"2026-03-27T12:46:17","modified_gmt":"2026-03-27T12:46:17","slug":"one-predator-scares-away-white-sharks-even-more-than-orcas-sciencealert","status":"publish","type":"post","link":"https:\/\/www.europesays.com\/us\/685524\/","title":{"rendered":"One Predator Scares Away White Sharks Even More Than Orcas : ScienceAlert"},"content":{"rendered":"<p>Off the coast of South Africa, near the fishing town of Gansbaai, two orcas have made a name for themselves worldwide.<\/p>\n<p>Their names are Port and Starboard, and on multiple occasions, they&#8217;ve been observed <a href=\"https:\/\/www.sciencealert.com\/great-white-sharks-were-scared-out-of-their-habitat-by-just-2-predators\" rel=\"nofollow noopener\" target=\"_blank\">hunting and killing<\/a> one of the most fearsome predators in the ocean: the great white shark, <a href=\"https:\/\/en.wikipedia.org\/wiki\/Great_white_shark\" rel=\"nofollow noopener\" target=\"_blank\">Carcharodon carcharias<\/a>.<\/p>\n<p>So efficient are the hunting skills of these two killer whales (<a href=\"https:\/\/en.wikipedia.org\/wiki\/Orca\" rel=\"nofollow noopener\" target=\"_blank\">Orcinus orca<\/a>) that some <a href=\"https:\/\/doi.org\/10.1002\/ecy.3875\" rel=\"nofollow noopener\" target=\"_blank\">scientists have attributed<\/a> the sharks&#8217; dwindling numbers in a once-heavily populated habitat to them.<\/p>\n<p>There&#8217;s just one problem, a new paper lays out. The orcas aren&#8217;t the real culprit. Rather, an even more efficient predator could be driving sharks from their home: us.<\/p>\n<p>In recent years, it has begun to emerge that killer whales are highly skilled hunters of sharks, including large species such as <a href=\"https:\/\/www.sciencealert.com\/orcas-have-a-killer-technique-to-hunt-the-biggest-fish-in-the-ocean\" rel=\"nofollow noopener\" target=\"_blank\">whale sharks<\/a> and <a href=\"https:\/\/www.sciencealert.com\/theres-one-predator-in-the-ocean-instilling-terror-in-great-white-sharks\" rel=\"nofollow noopener\" target=\"_blank\">great whites<\/a>.<\/p>\n<p>Orcas use echolocation to <a href=\"https:\/\/www.fisheries.noaa.gov\/feature-story\/sound-strategy-hunting-southern-residents-part-2\" rel=\"nofollow noopener\" target=\"_blank\">essentially ultrasound<\/a> a shark&#8217;s body, targeting the liver \u2013 rich in lipids that sustain sharks on long migrations \u2013 and extracting it with near-surgical precision.<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/www.europesays.com\/us\/wp-content\/uploads\/2025\/12\/1766369420_173_0.jpg\" alt=\"YouTube Thumbnail\" tabindex=\"0\" role=\"button\" class=\"youtube-thumbnail-preview\" loading=\"lazy\"\/> frameborder=&#8221;0\u2033 allow=&#8221;accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share&#8221; referrerpolicy=&#8221;strict-origin-when-cross-origin&#8221; allowfullscreen&gt;<\/p>\n<p>Between 2017 and 2025 \u2013 a span of about eight years \u2013 there were 11 documented occurrences of orca predation on white sharks, mostly wash-up carcasses, thought to be the work of Port and Starboard. In 2017, researchers watched as the pair killed and eviscerated 17 smaller sevengill sharks <a href=\"https:\/\/www.sciencealert.com\/two-orcas-went-on-feeding-frenzy-killing-17-sharks-in-one-sitting\" rel=\"nofollow noopener\" target=\"_blank\">in a single day<\/a>, but that was a rarity.<\/p>\n<p>It&#8217;s impossible to tell how many sharks Port and Starboard kill each year on average, since we can&#8217;t be sure humans always record the hunts.<\/p>\n<p>However, according to a paper led by marine biologist Enrico Gennari of the Oceans Research Institute in South Africa, humans likely have the killer whales beat hand over fist.<\/p>\n<p>He and his colleagues drew on multiple lines of evidence to estimate the anthropogenic white shark death toll among the South African population, and the numbers are far higher than known orca kills.<\/p>\n<p>Humans, they find, are removing an estimated 44 white sharks per year from coastal South Africa through the KwaZulu-Natal shark control program and as bycatch of <a href=\"https:\/\/news.mongabay.com\/2025\/10\/south-african-sharks-threatened-by-fisheries-weak-enforcement\/\" rel=\"nofollow noopener\" target=\"_blank\">longline shark fisheries<\/a>.<\/p>\n<p>Historically, this line of enquiry has been complicated. In 1991, South Africa became the first nation to <a href=\"https:\/\/hdl.handle.net\/10520\/AJA00382353_6665\" rel=\"nofollow noopener\" target=\"_blank\">enact legislation protecting<\/a> the great white shark. Subsequently, it needed to monitor shark populations and take measures to protect them.<\/p>\n<p>However, exactly what those white shark populations are doing has been the subject of debate. A 2023 study suggested the sharks have not declined, but instead <a href=\"https:\/\/doi.org\/10.1016\/j.ecolind.2023.110720\" rel=\"nofollow noopener\" target=\"_blank\">shifted their range eastward<\/a>, with the same group of researchers <a href=\"https:\/\/doi.org\/10.1016\/j.ecolind.2024.112160\" rel=\"nofollow noopener\" target=\"_blank\">clarifying in 2024<\/a> that the lack of population growth since the 1991 protections was nevertheless cause for concern.<\/p>\n<p>The narrative of a stable population <a href=\"https:\/\/www.dailymaverick.co.za\/article\/2024-03-12-scientists-challenge-research-showing-sas-white-shark-population-is-stable\/\" rel=\"nofollow noopener\" target=\"_blank\">may limit the urgency<\/a> with which governments consider further conservation efforts, researchers warned.<\/p>\n<p>Gennari and his colleagues <a href=\"https:\/\/doi.org\/10.3354\/esr01465\" rel=\"nofollow noopener\" target=\"_blank\">argue<\/a> in their opinion piece that the broader evidence is more concerning. The white shark population is not stable, they say, but declining. And this has graver implications for the species globally.<\/p>\n<p>&#8220;If the worrying declines observed in what were once considered the largest aggregation sites of white sharks in the world, in just less than a 15 yr period, were representative of the entire population of white sharks in southern Africa, as we believe they are,&#8221; <a href=\"https:\/\/doi.org\/10.3354\/esr01465\" rel=\"nofollow noopener\" target=\"_blank\">the researchers write<\/a>, &#8220;the situation would be extremely alarming, and the possible extinction risk could happen much earlier than modelled.&#8221;<\/p>\n<p><a href=\"https:\/\/www.sciencealert.com\/newsletter?utm_source=promo_generic_health\" rel=\"nofollow noopener\" target=\"_blank\"><img decoding=\"async\" src=\"https:\/\/www.europesays.com\/us\/wp-content\/uploads\/2025\/11\/Generic-Health-Promo-Final-642x273.jpg\" alt=\"Subscribe to ScienceAlert's free fact-checked newsletter\" width=\"642\" height=\"273\" class=\"alignnone wp-image-182810 size-medium\"   loading=\"lazy\"\/><\/a><\/p>\n<p>The most recent count of white shark numbers used data up to 2011 and estimated that the population swam at <a href=\"https:\/\/doi.org\/10.1371\/journal.pone.0066035\" rel=\"nofollow noopener\" target=\"_blank\">around 908 individuals<\/a>. Subsequent analyses incorporating genetic data published in 2016 suggested there are <a href=\"https:\/\/theconversation.com\/i-spent-the-past-seven-years-counting-white-sharks-the-findings-are-troubling-62567\" rel=\"nofollow noopener\" target=\"_blank\">only 333 mature individuals<\/a> in a single interbreeding population along the South African coast.<\/p>\n<p>No census has been taken since then \u2013 and sightings of the animals have fallen dramatically in some places.<\/p>\n<p>In False Bay, near Cape Town, white sharks could be seen at a rate of about <a href=\"https:\/\/climatecompass247.com\/science\/this-was-once-the-best-place-to-see-great-white-sharks-then-they-disappeared\/\" rel=\"nofollow noopener\" target=\"_blank\">1.64 per hour<\/a> between 2000 and 2015. Between 2016 and 2020, that rate dropped to 0.3 sharks per hour. By 2018, the number was <a href=\"https:\/\/www.frontiersin.org\/journals\/marine-science\/articles\/10.3389\/fmars.2025.1530362\/full\" rel=\"nofollow noopener\" target=\"_blank\">effectively zero in boat-based surveys<\/a>.<\/p>\n<p>Gennari and colleagues are likewise concerned that the white shark population is in decline. They estimate that the 44 white sharks killed each year, through the demersal shark longline (DSL) fishery regulated by the South African government and the KZNSB shark control program, amount to around 5 to 10 percent of the estimated population yearly.<\/p>\n<p>That&#8217;s unsustainable on its own, and it&#8217;s not even accounting for other sources of human-caused mortality not included in the estimate.<\/p>\n<p><strong>Related: <a href=\"https:\/\/www.sciencealert.com\/theres-one-predator-in-the-ocean-instilling-terror-in-great-white-sharks\" rel=\"nofollow noopener\" target=\"_blank\">There&#8217;s One Predator in The Ocean Instilling Terror in Great White Sharks<\/a><\/strong><\/p>\n<p>We can&#8217;t control what Port and Starboard do, obviously \u2013 but that, the researchers say, makes it even more important to impose limits on human activity that <a href=\"https:\/\/sharkallies.org\/valuation-reports\/south-africa-white-sharks-valuation-report-5ztrr\" rel=\"nofollow noopener\" target=\"_blank\">endangers this population of sharks<\/a>.<\/p>\n<p>&#8220;Predation by orcas is a natural phenomenon that, no matter the level, does not fall under management control of the government of South Africa, similarly to other sources of mortality occurring in international waters,&#8221; <a href=\"https:\/\/doi.org\/10.3354\/esr01465\" rel=\"nofollow noopener\" target=\"_blank\">the researchers write<\/a>.<\/p>\n<p>&#8220;However, the ongoing mortality of white sharks from the DSL and KZNSB, which do fall under government regulation, [is] alone at levels sufficient to prevent white shark recovery, and likely to drive its decline.&#8221;<\/p>\n<p>&#8220;While South Africa was the first nation to protect white sharks,&#8221; <a href=\"https:\/\/doi.org\/10.3354\/esr01465\" rel=\"nofollow noopener\" target=\"_blank\">the team concludes<\/a>, &#8220;we fear that it may soon also hold the title as the first nation to lose this species.&#8221;<\/p>\n<p>The report was published in <a href=\"https:\/\/doi.org\/10.3354\/esr\" rel=\"nofollow noopener\" target=\"_blank\">Endangered Species Research<\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":"Off the coast of South Africa, near the fishing town of Gansbaai, two orcas have made a name&hellip;\n","protected":false},"author":3,"featured_media":685525,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[27],"tags":[352,159,67,132,68,837],"class_list":{"0":"post-685524","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-wildlife","8":"tag-msft-content","9":"tag-science","10":"tag-united-states","11":"tag-unitedstates","12":"tag-us","13":"tag-wildlife"},"share_on_mastodon":{"url":"https:\/\/pubeurope.com\/@us\/116301213640775286","error":""},"_links":{"self":[{"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/posts\/685524","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/comments?post=685524"}],"version-history":[{"count":0,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/posts\/685524\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/media\/685525"}],"wp:attachment":[{"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/media?parent=685524"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/categories?post=685524"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/tags?post=685524"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}