All articles tagged with #marine biology
A bull southern elephant seal sets a record by diving up to 2,388 meters and holding its breath for up to two hours, aided by storing three times more oxygen in its blood than humans, a slowed heart rate, and tissue oxygen reserves, while hunting squid and rays in nutrient-rich zones.
A long-term study of whale records along the Benguela coast (Namibia and South Africa) shows blue and fin whales are slowly reoccupying parts of their former southeast Atlantic range after decades of commercial whaling that killed hundreds of thousands of individuals. Sightings have risen since 2012, but both species remain far below historic levels and face ongoing threats from ships, fishing gear, noise, pollution, and climate-driven shifts in prey. The researchers urge expanded acoustic monitoring, trained vessel observers, and habitat-based planning to sustain the ongoing recovery.
Researchers off Hervey Bay, Australia filmed dolphins using empty seashells to trap fish, with a mother and calf showcasing the behavior. This is the first video evidence of shelling as a prey-catching tactic, suggesting potential maternal transmission and possibly independent emergence across populations, highlighting dolphins’ intelligence and prompting questions about the evolution of tool use.
Researchers in Queensland, Australia captured the first evidence of bottlenose dolphins using empty seashells to catch fish, a behavior called shelling. The footage shows dolphins herding fish into shells, lifting the shells to the surface, and shaking them to drain prey, with a calf imitating its mother, suggesting maternal social transmission. The findings extend the known range of shelling to the east coast and indicate sophisticated tool use and learning in dolphins, highlighting the need for further study.
Fifteen years ago, a Japanese research team photographed about 100 neon flying squid leaping from the Pacific and gliding in near-formation for roughly 30 meters, likely using their hyponomes to propel themselves. The neon flying squid (Ommastrephes bartramii) are social cephalopods that rise near the surface to feed, and while the exact purpose of the group gliding remains unclear, predator evasion is a leading hypothesis.
Dolphins off the coast of Queensland, Australia, have been filmed using empty seashells to stun and extract fish—a rare foraging method called shelling. New 2025 footage, along with a Marine Mammal Science study, shows an adult female and her calf shelling together, hinting that mothers may teach this technique to offspring and that the behavior could spread within populations. Previously, shelling was only documented in Shark Bay, Western Australia; researchers plan further study to understand learning pathways across popuations.
A tongue-eating isopod (Cymothoa exigua) enters a fish through the gills, drains blood from the tongue to cause it to wither, and then clamps onto the tongue’s stump to function as the fish’s new tongue for the rest of its life. The species is protandrous hermaphroditic, with rare cases of a female at the tongue site and a male in the gill chamber; researchers have identified related mouth-dwelling isopods (including Cymothoa facimar) and noted how parasite load can vary with fishing pressure and market sightings.
The bootlace worm (Lineus longissimus) can reach extraordinary lengths, with rare reports of up to 55 meters and a typical length around 15 meters. When threatened, it releases a poisonous mucus containing alpha-nemertides that paralyze crabs and can kill insects, a potential source for new insecticides, highlighting this remarkable nemertean as a formidable, though overlooked, marine predator.
Five blue whales and four humpbacks were tagged to measure heart rates during lunge-feeding; results show heart rates rise to about 21.9 bpm (blue whales) and 28.2 bpm (humpbacks) during lunges and then slowly fall between lunges, indicating a mix of anaerobic energy and rapid recovery that enables feeding while conserving oxygen. Resting rates were as low as 18.5 bpm, highlighting a shared metabolic pattern and potential health indicators for whales amid changing prey and noise pollution.
Researchers from Murdoch University fitted whale sharks with small on-body cameras to document their underwater foraging, uncovering six frequent low-effort feeding tactics and a broader range of strategies than other large filter feeders, including active feeding when krill patches appear, offering new insights into how these endangered giants eat and survive in tropical waters.
In Cornwall, snorkeler Katie Maggs encounters a translucent comb jelly whose comb rows refract light as it glides by, creating a rainbow glow (not bioluminescence) that leaves her and online viewers spellbound.
In Marina Palamós, five Mediterranean sponge species were transplanted into a polluted harbor. Four failed, but the chicken kidney sponge (Chondrosia reniformis) survived 91.7% over 455 days and reproduced by creeping and fission, suggesting native sponges could aid harbor cleanup by filtering pollutants and supporting habitat restoration.
A 2020 study of Cuvier’s beaked whales logged a 222-minute dive on a single breath, the longest mammal dive on record and far exceeding prior aerobic dive-limit estimates (about 33–78 minutes). Analyzing thousands of dives from 23 tagged whales off Cape Hatteras, researchers found a median around an hour but two extreme dives that pushed the known limits. The findings point to a combination of high oxygen storage, low metabolic rate, and metabolic buffering, yet recovery patterns did not follow a simple rule, leaving the true limits and mechanisms unresolved.
Marine researchers exploring Rotuma, Fiji, in a deep-sea submersible at about 365 metres witnessed a nautilus swim up to the vehicle and hover at eye level, a rare encounter with this ancient mollusc that inhabits the twilight zone and relies on gas-filled buoyant chambers. The moment highlights the nautilus’s continued presence in deep-sea ecosystems and underscores the importance of protecting these habitats for deep-sea species.
Researchers from the California White Shark Project propose a systematic way to interpret scars on great white sharks, based on a 2025 Frontiers in Marine Science study. They cite a 16‑ft female great white with a circular head wound from a cookiecutter shark as an example, showing how scar patterns reveal interactions with prey, boats, mates, or entanglement. The team suggests offshore migration brings cookiecutter encounters and that certain scars—like hold bites that heal—could indicate offshore mating, helping scientists infer where and when white sharks reproduce.