Using synchrotron X-ray nanotomography with detailed 3D imaging and in-situ mechanical testing, researchers are peering inside shark skeletons at the nanoscale, revealing a microscopic “sharkitecture” that helps these ancient apex predators withstand extreme physical demands of constant motion. After hundreds of millions of years of evolution, scientists can now finally see how shark cartilage works at the nanoscale – and learn from them.

Animals facing distress due to human action or aggression may react in several ways, for example, by fleeing or retaliating. New research showed that sharks may defend themselves – not unlike land-dwelling animals or humans. In French Polynesia, scientists observed a previously undocumented, rapidly delivered but usually non-lethal type of shark bite in response to human aggression. These new insights should be considered by the media to stop systematically blaming sharks, especially if motivated by self-defense, the researchers said.

A marine conservation incentive program in Indonesia successfully increased the overall rate of live release for critically endangered wedgefish and hammerhead sharks, according to a new study. Participants in the program were paid for each fish they captured and released live, as documented on video. However, some vessels began targeting the cartilaginous fishes, so as to release more and earn more compensation. This complicated the approach’s impact on fish mortality; while wedgefish mortality did decrease, hammerhead shark mortality increased. “Our results do not imply that a pay-to-release program cannot work in Indonesia, but rather they offer valuable insights into how such programs could be more effectively designed and deployed,” Hollie Booth and colleagues write. Lately, conservationists and policymakers have proposed incentive strategies, such as pay-to-release programs, to protect cartilaginous fishes. The pay-to-release approach is particularly appealing for small-scale fisheries (SSFs) in the Global South, because it prevents fishers from suffering economic loss at the cost of conservation. Yet, there has been a shortage of empirical evidence about the efficacy of pay-to-release programs. Now, Booth et al. provide results from a randomized, controlled, pre-registered, pay-to-release trial involving 87 small-scale fishing vessels in 5 Indonesian villages in East Lombok and Aceh Jaya. Based solely on tracking live releases from videos, the team calculated this incentive reduced wedgefish mortality by 71% and hammerhead shark mortality by 4%. However, interviews with fishers and vessel surveys changed these statistics. Some SSFs reported catching more of the fish deliberately to then conduct more live releases, and thus receive more pay. Since live release does not always mean the fish survives afterwards, the authors adjusted the findings: wedgefish mortality decreased just 25% – and hammerhead mortality actually increased by 44%. “Given the importance of program design and implementation context, we do not wish to speculate about the degree to which our results generalize to other areas or time periods,” they caution.

Okinawa and its surrounding waters represent what marine biologists call a "shark and ray hotspot" in terms of both diversity and conservation significance. In this episode of the OIST podcast, Dr. Fabienne Ziadi-Künzli, a marine biologist and shark researcher at the Okinawa Institute of Science and Technology (OIST), explained that this region creates unique habitats for sharks throughout their different life stages.

A new Flinders University-led research paper, published in Marine Environmental Research, shows that chemicals used to preserve shark jaws do not affect the isotopes, enabling preserved jaws to be used for revealing what sharks eat and where they feed.

Nearly one-third of sharks are threatened with extinction, mostly due to fishing. While mandated releases are helpful, researchers discovered that they aren't enough to stabilize shark populations.

A new scientific study provides many new insights into the biology of the prehistoric gigantic shark, Megalodon or megatooth shark, which lived nearly worldwide 15-3.6 million years ago. Paleobiology professor Kenshu Shimada of DePaul University led the study along with 28 other shark, fossil, and vertebrate anatomy experts around the globe. Findings from the study will be published in the journal “Palaeontologia Electronica.”