Lemon Shark in black and white

Sharks

Palaeohypotodus bizzocoi tooth.
Palaeohypotodus bizzocoi tooth. /McWane Science Center.

Scientists discover fossilized remains of new ancient shark species

Palaeohypotodus, pronounced pale-ee-oh-hype-oh-toe-duss, translates to "ancient small-eared tooth," a reference to the shark's distinctive small needle-like fangs found on the sides of its teeth. Spearheaded by Jun Ebersole, Director of Collections at McWane Science Center in Birmingham, alongside David Cicimurri, Curator of Natural History at South Carolina State Museum, and T. Lynn Harrell, Jr., Paleontologist and Fossil Collections Curator at the Geological Survey of Alabama in Tuscaloosa, the team named the new species in honour of the late Dr.

Newborn White Shark Pup
Newborn white shark pup (Photo by Carlos Gauna)

Drone discovery: A newborn great white shark

(TOP BANNER IMAGE: Carlos Gauna/The Malibu Artist) 

The remarkable sighting occurred on 9 July 2023, approximately 400m (1,300ft) off the shores of Carpinteria, California. Wildlife filmmaker Carlos Gauna and Phillip Sternes, a doctoral student in the Department of Biology at the University of California Riverside, stumbled upon the extraordinary sight while filming aerial footage.

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drying shark fins
Demands of the shark fin trade

Global challenges and evolving threats: A comprehensive analysis of shark fishing

The ancient group of marine predators, which first appeared in the fossil record 440 million years ago, are facing a critical juncture in their existence. Though they have been resilient to other mass extinctions, the current one is caused by decades of industrial overfishing along with the growing demands of the shark fin trade. It has put those shark and ray species accessible to fisheries at risk of extinction, with far-reaching consequences for ocean ecosystems.

Shark dorsal fin with shark still attached.

Shark conservation: A critical reassessment needed

Over the past two decades, sharks have become emblematic of the world's threatened wildlife, leading to heightened scientific, regulatory and public scrutiny. However, a recent study challenges the effectiveness of these protective measures, revealing that global shark mortality has not only persisted but increased, despite increased regulations and finning bans.

If a shark or other animal is captured, the pressure on the line triggers the communications unit, which then sends an alert via phone call, email and text message to a boat crew who will respond to the animal within 30 minutes. If it is a target shark, namely a white, bull or tiger shark, it will be tagged and then released one kilometre offshore. All other marine animals caught are released immediately.

Catch-and-release deters sharks from beaches

Researchers conducted trials using SMART drumlines in New South Wales, Australia, to catch and release sharks, particularly White Sharks. The study aimed to quantify the short-term post-release movements and the longer-term fate of these sharks.

Sharks were caught using SMART drumlines deployed about 500 meters from shore. Once captured, they were quickly secured to a research vessel, minimising potential injuries. The sharks were tagged with satellite-linked radio transmitting tags and acoustic transmitters to monitor their movements post-release.

A quick pass into view.

Enigmatic world of shark and ray behaviour unveiled

Elasmobranchs have become lucrative targets with the depletion of traditional fish stocks and the surge in the shark fin trade. Although, in recent decades, much scientific evidence has challenged traditional misconceptions, stereotyped media portrayals persist, and they hinder conservation efforts. So, this special issue was created to highlight the complex behaviour and cognition of sharks and rays.

Baby hammerhead during development with a nascent hammerhead snout.
Baby hammerhead during development with a nascent hammerhead snout.

How hammerheads grow their hammers

In an unprecedented study, scientists from the University of Florida (UF) have delved into the development of hammerhead sharks' skulls, uncovering the process behind their iconic hammer-like shape at the embryonic stage.

Led by UF professor Gareth Fraser, the study focussed on bonnetheads, the smallest among the hammerhead shark species. The species’ abundance in the Gulf of Mexico and the Atlantic Ocean, along with their near-shore presence, made them ideal subjects for the study.

The revelation that basking sharks are partially warm-blooded adds a fascinating layer to our knowledge of these gentle giants. It underscores the complexity of marine life and the continuous surprises it holds.
The revelation that basking sharks are partially warm-blooded adds a fascinating layer to our knowledge of these gentle giants. It underscores the complexity of marine life and the continuous surprises it holds.

Basking sharks are not cold-blooded

The revelation that basking sharks are partially warm-blooded challenges previous assumptions about the physiology of these colossal creatures and has significant implications for their conservation and understanding of marine ecosystems.

Ecotourism increases the probability of sharks being in a disturbed behavioural state, likely increasing energetic expenditure and potentially leading to downstream ecological effects.

Behavioural consequences of shark ecotourism

Ecotourism, particularly shark diving tourism, has become a significant global industry, attracting over half a million participants annually across approximately 85 countries. While it generates substantial revenue and raises awareness for shark conservation, concerns about its impact on shark behaviour and health, as well as human safety, persist.

Ecotourism has been posited as a potential solution to many of the issues facing shark conservation, yet increasingly studies suggest that such activity may negatively influence aspects of shark ecology and so further pressure declining populations.

— Joel H. Gayford, et al.