Starving bacteria (cyan) use a microscopic harpoon—called the Type VI secretion system—to stab and kill neighboring cells (magenta). The prey burst, turning spherical and leaking nutrients, which the killers then use to survive and grow. (Image Credit: Glen D'Souza/ASU/Screen shot from video)NewsletterSign up for our email newsletter for the latest science newsBacteria are bad neighbors. And we’re not talking noisy, never-take-out-the-trash bad neighbors. We’re talking has-a-harpoon-gun-and-points-it-at-you bad neighbors. According to a new study in Science, some bacteria hunt nearby bacterial species when they’re hungry. Using a special weapon system called the Type VI Secretion System (T6SS), these bacteria shoot, spill, and then absorb the nutrients from the microbes they harpoon. “The punchline is: When things get tough, you eat your neighbors,” said Glen D’Souza, a study author and an assistant professor at Arizona State University, according to a press release. “We’ve known bacteria kill each other, that’s textbook. But what we’re seeing is that it’s not just important that the bacteria have weapons to kill, but they are controlling when they use those weapons specifically for situations to eat others where they can’t grow themselves.” According to the study authors, the research doesn’t just have implications for bacterial neighborhoods; it also has implications for human health and medicine. By harnessing these bacterial weapons, it may be possible to build better targeted antibiotics, designed to overcome antibiotic resistance. Ruthless Bacteria Use HarpoonsResearchers have long known that some bacteria can be ruthless, using weapons like the T6SS to clear out their competition. A nasty tool, the T6SS is essentially a tiny harpoon gun with a poison-tipped needle. When a bacterium shoots the weapon into another bacterium from a separate species, the needle pierces the microbe without killing it. Then, it injects toxins into the microbe that cause its internal nutrients to spill out.Up until now, researchers thought that this weapon helped bacteria eliminate their competition for space and for food, but after watching bacteria use the T6SS to attack their neighbors when food was scarce, the study authors concluded that these tiny harpooners use the weapon not only to remove rivals, but also to consume their competitors’ leaked nutrients.“Watching these cells in action really drives home how resourceful bacteria can be,” said Astrid Stubbusch, another study author and a researcher who worked on the study while at ETH Zurich, according to the press release. “By slowly releasing nutrients from their neighbors, they maximize their nutrient harvesting when every molecule counts.” Absorbing Food From NeighborsTo show that the bacteria used this system to eat when there was no food around, the study authors compared their attacks in both nutrient-rich and nutrient-poor environments. When supplied with ample resources, the bacteria used their harpoons to kill their neighbors quickly, with the released nutrients leaking out and dissolving immediately. But when resources were few and far between, they used their harpoons to kill their neighbors slowly, with the nutrients seeping out and sticking around. “This difference in dissolution time could mean that the killer cells load their spears with different toxins,” D’Souza said in another press release. While one toxin could eliminate the competition for space and for food when nutrients are available, another could create a food source, allowing bacteria to “absorb as many nutrients as possible” when sustenance is in short supply.Because of all this, this weapon system is more than ruthless; it’s also smart, and important to some species’ survival. When genetically unedited T6SS bacteria were put in an environment without food, they survived on spilled nutrients. But when genetically edited T6SS bacteria were placed in a similar environment, they died, because their ability to find food in their neighbors had been “turned off.”Harnessing Bacterial HarpoonsAccording to the study authors, the T6SS system is widely used by bacteria, both in and outside the lab. “It’s present in many different environments,” D’Souza said in one of the press releases. “It’s operational and happening in nature, from the oceans to the human gut.” The study authors add that their research could change the way we think about bacteria and could help in our fight against antibiotic resistance. In fact, the T6SS could one day serve as a foundation for targeted drug delivery systems, which could mitigate the development of broader bacterial resistance to antibiotics. But before that can happen, however, researchers have to learn more about bacterial harpoons, and about when and how bacteria use them, both to beat and eat their neighbors.Article SourcesOur writers at Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles, and our editors review for scientific accuracy and editorial standards. Review the sources used below for this article:Sam Walters is a journalist covering archaeology, paleontology, ecology, and evolution for Discover, along with an assortment of other topics. Before joining the Discover team as an assistant editor in 2022, Sam studied journalism at Northwestern University in Evanston, Illinois.1 free article leftWant More? Get unlimited access for as low as $1.99/monthSubscribeAlready a subscriber?Register or Log In1 free articleSubscribeWant more?Keep reading for as low as $1.99!SubscribeAlready a subscriber?Register or Log In

Big and Small Underwater Faces — 3rd Place. Trips to the Antarctic Peninsula always yield amazing encounters with leopard seals (Hydrurga leptonyx). Boldly approaching me and baring his teeth, this individual was keen to point out that this part of Antarctica was his territory. This picture was shot at dusk, resulting in the rather moody atmosphere.   Credit: Lars von Ritter Zahony (Germany) / World Ocean’s Day Get the Popular Science daily newsletter💡 Breakthroughs, discoveries, and DIY tips sent every weekday. The striking eye of a humpback whale named Sweet Girl peers at the camera. Just four days later, she would be dead, hit by a speeding boat and one of the 20,000 whales killed by ship strikes each year. Photographer Rachel Moore’s captivating image (seen below) of Sweet Girl earned top honors at the 2025 United Nations World Oceans Day Photo Competition. Wonder: Sustaining What Sustains Us — WinnerThis photo, taken in Mo’orea, French Polynesia in 2024, captures the eye of a humpback whale named Sweet Girl, just days before her tragic death. Four days after I captured this intimate moment, she was struck and killed by a fast-moving ship. Her death serves as a heartbreaking reminder of the 20,000 whales lost to ship strikes every year. We are using her story to advocate for stronger protections, petitioning for stricter speed laws around Tahiti and Mo’orea during whale season. I hope Sweet Girl’s legacy will spark real change to protect these incredible animals and prevent further senseless loss.Credit: Rachel Moore (USA) / United Nations World Oceans Day www.unworldoceansday.org Now in its twelfth year, the competition coordinated in collaboration between the UN Division for Ocean Affairs and the Law of the Sea, DivePhotoGuide (DPG), Oceanic Global, and  the Intergovernmental Oceanographic Commission of UNESCO. Each year, thousands of underwater photographers submit images that judges award prizes for across four categories: Big and Small Underwater Faces, Underwater Seascapes, Above Water Seascapes, and Wonder: Sustaining What Sustains Us. This year’s winning images include a curious leopard seal, a swarm of jellyfish, and a very grumpy looking Japanese warbonnet. Given our oceans’ perilous state, all competition participants were required to sign a charter of 14 commitments regarding ethics in photography. Underwater Seascapes — Honorable MentionWith only orcas as their natural predators, leopard seals are Antarctica’s most versatile hunters, preying on everything from fish and cephalopods to penguins and other seals. Gentoo penguins are a favored menu item, and leopard seals can be observed patrolling the waters around their colonies. For this shot, I used a split image to capture both worlds: the gentoo penguin colony in the background with the leopard seal on the hunt in the foreground.Credit: Lars von Ritter Zahony (Germany) / United Nations World Oceans Day www.unworldoceansday.org Above Water Seascapes – WinnerA serene lake cradled by arid dunes, where a gentle stream breathes life into the heart of Mother Earth’s creation: Captured from an airplane, this image reveals the powerful contrasts and hidden beauty where land and ocean meet, reminding us that the ocean is the source of all life and that everything in nature is deeply connected. The location is a remote stretch of coastline near Shark Bay, Western Australia.Credit: Leander Nardin (Austria) / United Nations World Oceans Day www.unworldoceansday.org Above Water Seascapes — 3rd PlaceParadise Harbour is one of the most beautiful places on the Antarctic Peninsula. When I visited, the sea was extremely calm, and I was lucky enough to witness a wonderfully clear reflection of the Suárez Glacier (aka Petzval Glacier) in the water. The only problem was the waves created by our speedboat, and the only way to capture the perfect reflection was to lie on the bottom of the boat while it moved towards the glacier.Credit: Andrey Nosik (Russia) / United Nations World Oceans Day www.unworldoceansday.org Underwater Seascapes — 3rd Place“La Rapadura” is a natural hidden treasure on the northern coast of Tenerife, in the Spanish territory of the Canary Islands. Only discovered in 1996, it is one of the most astonishing underwater landscapes in the world, consistently ranking among the planet’s best dive sites. These towering columns of basalt are the result of volcanic processes that occurred between 500,000 and a million years ago. The formation was created when a basaltic lava flow reached the ocean, where, upon cooling and solidifying, it contracted, creating natural structures often compared to the pipes of church organs. Located in a region where marine life has been impacted by once common illegal fishing practices, this stunning natural monument has both geological and ecological value, and scientists and underwater photographers are advocating for its protection. (Model: Yolanda Garcia)Credit: Pedro Carrillo (Spain) / United Nations World Oceans Day www.unworldoceansday.org Underwater Seascapes — WinnerThis year, I had the incredible opportunity to visit a jellyfish lake during a liveaboard trip around southern Raja Ampat, Indonesia. Being surrounded by millions of jellyfish, which have evolved to lose their stinging ability due to the absence of predators, was one of the most breathtaking experiences I’ve ever had.Credit: Dani Escayola (Spain) / United Nations World Oceans Day www.unworldoceansday.org Underwater Seascapes — 2nd PlaceThis shot captures a school of rays resting at a cleaning station in Mauritius, where strong currents once attracted them regularly. Some rays grew accustomed to divers, allowing close encounters like this. Sadly, after the severe bleaching that the reefs here suffered last year, such gatherings have become rare, and I fear I may not witness this again at the same spot.Credit: Gerald Rambert (Mauritius) / United Nations World Oceans Day www.unworldoceansday.org Wonder: Sustaining What Sustains Us — 3rd PlaceShot in Cuba’s Jardines de la Reina—a protected shark sanctuary—this image captures a Caribbean reef shark weaving through a group of silky sharks near the surface. Using a slow shutter and strobes as the shark pivoted sharply, the motion blurred into a wave-like arc across its head, lit by the golden hues of sunset. The abundance and behavior of sharks here is a living symbol of what protected oceans can look like.Credit: Steven Lopez (USA) / United Nations World Oceans Day www.unworldoceansday.org  Above Water Seascapes — 2nd PlaceNorthern gannets (Morus bassanus) soar above the dramatic cliffs of Scotland’s Hermaness National Nature Reserve, their sleek white bodies and black-tipped wings slicing through the Shetland winds. These seabirds, the largest in the North Atlantic, are renowned for their striking plunge-dives, reaching speeds up to 100 kph (60 mph) as they hunt for fish beneath the waves. The cliffs of Hermaness provide ideal nesting sites, with updrafts aiding their take-offs and landings. Each spring, thousands return to this rugged coastline, forming one of the UK’s most significant gannet colonies. It was a major challenge to take photos at the edge of these cliffs at almost 200 meters (650 feet) with the winds up to 30 kph (20 mph).Credit: Nur Tucker (UK/Turkey) / United Nations World Oceans Day www.unworldoceansday.org Above Water Seascapes — Honorable MentionA South Atlantic swell breaks on the Dungeons Reef off the Cape Peninsula, South Africa, shot while photographing a big-wave surf session in October 2017. It’s the crescendoing sounds of these breaking swells that always amazes me.Credit: Ken Findlay (South Africa) / United Nations World Oceans Day www.unworldoceansday.org Wonder: Sustaining What Sustains Us — Honorable MentionHumpback whales in their thousands migrate along the Ningaloo Reef in Western Australia every year on the way to and from their calving grounds. In four seasons of swimming with them on the reef here, this is the only encounter I’ve had like this one. This pair of huge adult whales repeatedly spy-hopped alongside us, seeking to interact with and investigate us, leaving me completely breathless. The female in the foreground was much more confident than the male behind and would constantly make close approaches, whilst the male hung back a little, still interested but shy. After more than 10 years working with wildlife in the water, this was one of the best experiences of my life.Credit: Ollie Clarke (UK) / United Nations World Oceans Day www.unworldoceansday.org Big and Small Underwater Faces — 2nd PlaceOn one of my many blackwater dives in Anilao, in the Philippines, my guide and I spotted something moving erratically at a depth of around 20 meters (65 feet), about 10 to 15 centimeters in size. We quickly realized that it was a rare blanket octopus (Tremoctopus sp.). As we approached, it opened up its beautiful blanket, revealing its multicolored mantle. I managed to take a few shots before it went on its way. I felt truly privileged to have captured this fascinating deep-sea cephalopod. Among its many unique characteristics, this species exhibits some of the most extreme sexual size-dimorphism in nature, with females weighing up to 40,000 times more than males.Credit: Giacomo Marchione (Italy) / United Nations World Oceans Day www.unworldoceansday.org Big and Small Underwater Faces – WinnerThis photo of a Japanese warbonnet (Chirolophis japonicus) was captured in the Sea of Japan, about 50 miles (80 kilometers) southwest of Vladivostok, Russia. I found the ornate fish at a depth of about 30 meters (100 feet), under the stern of a shipwreck. This species does not appear to be afraid of divers—on the contrary, it seems to enjoy the attention—and it even tried to sit on the dome port of my camera.Credit: Andrey Nosik (Russia) / United Nations World Oceans Day www.unworldoceansday.org Wonder: Sustaining What Sustains Us — 2nd PlaceA juvenile pinnate batfish (Platax pinnatus) captured with a slow shutter speed, a snooted light, and deliberate camera panning to create a sense of motion and drama. Juvenile pinnate batfish are known for their striking black bodies outlined in vibrant orange—a coloration they lose within just a few months as they mature. I encountered this restless subject in the tropical waters of Indonesia’s Lembeh Strait. Capturing this image took patience and persistence over two dives, as these active young fish constantly dart for cover in crevices, making the shot particularly challenging.Credit: Luis Arpa (Spain) / United Nations World Oceans Day www.unworldoceansday.org

A bubble ring created by a humpback whale named Thorn. Image © Dan Knaub, The Video Company Humpback Whales Are Approaching People to Blow Rings. What Are They Trying to Say? June 13, 2025 NatureSocial Issues Grace Ebert After the “orca uprising” captivated anti-capitalists around the world in 2023, scientists are intrigued by another form of marine mammal communication. A study released this month by the SETI Institute and the University of California at Davis dives into a newly documented phenomenon of humpback whales blowing bubble rings while interacting with humans. In contrast to the orcas’ aggressive behavior, researchers say the humpbacks appear to be friendly, relaxed, and even curious. Bubbles aren’t new to these aquatic giants, which typically release various shapes when corraling prey and courting mates. This study follows 12 distinct incidents involving 11 whales producing 39 rings, most of which have approached boats near Hawaii, the Dominican Republic, Mo’orea, and the U.S. Atlantic coast on their own. The impact of this research reaches far beyond the oceans, though. Deciphering these non-verbal messages could aid in potential extraterrestrial communication, as they can help to “develop filters that aid in parsing cosmic signals for signs of extraterrestrial life,” a statement says. “Because of current limitations on technology, an important assumption of the search for extraterrestrial intelligence is that extraterrestrial intelligence and life will be interested in making contact and so target human receivers,” said Dr. Laurance Doyle, a SETI Institute scientist who co-wrote the paper. “This important assumption is certainly supported by the independent evolution of curious behavior in humpback whales.” (via PetaPixel) A composite image of at least one bubble ring from each interaction Previous articleNext article

Otherwise it cannot protect them properly