So I asked leading shark ethologist and behaviourist, Professor Samuel 'doc' Gruber to elaborate. After pointing out how much pain women feel when they give birth, making the point that suffering has no effect on reproduction, he reminded me that sharks evolved their mating behaviours and the physical structures involved, separately from other animals.
Featuring some unbelievable dive expeditions around the globe, items are up for bid until June 17th and can be viewed here: auction.sharkangels.org
“This year’s auction is bigger & better than ever,” says Executive Director, Jamie Pollack. “We’re thrilled with the support we’ve received from many of our regular donors and excited about our partnerships with new donors.
Most sharks give birth to live young, but a few species, known as oviparous sharks, lay eggs. The new species could be identified because researchers noticed something interesting about its egg cases, pouches that attach to a surface in the ocean and hold onto a fertilized shark eggs as it develops.
(VIDEO: Researcher Al Dove collecting a blood sample. Video by Dr Simon Pierce)
DS: What were some of the challenges encountered when doing underwater ultrasounds? How did the team overcome them?
As fans of crime series will know, every living creature sheds DNA through skin cells, hair, scales and other bodily secretions as they move. This leaves behind a trace in whatever environment they were in, thus becoming environmental DNA (eDNA).
An emerging molecular technique called eDNA analysis enables researchers to scan samples of water, air, or soil for tiny remnants of DNA and identify organisms it came from.
Genomic data reveals historical population declines and high levels of inbreeding in great hammerhead.
In a recent report by the IUCN Red List of Threatened Species, 31 percent of all shark species are threatened (Critically Endangered, Endangered or Vulnerable). In 1980, only 9 species of oceanic sharks and rays were listed as threatened.
Shark dives provide an excellent way to meet a lot of sharks, and represent a unique situation in which sharks are treated well by humanity.
Shark dive clubs usually bring some fishy scraps—in most cases the remains left over after big fish have been cut up for sale. The scent attracts the sharks into view, and provides a bit of excitement as the animals investigate and try to get a piece.
The shark and ray population in the north Atlantic are in recovery, according to a recent study published in the Proceedings of the National Academy of Sciences (PNAS) journal.
Lead author Nathan Pacoureau, postdoctoral research fellow at Simon Fraser University (SFU), and his team came to this conclusion after analyzing trends in fishing pressure, fisheries management and population status for wide-ranging coastal sharks and rays in the western Atlantic Ocean.
Sand tiger sharks, top predators that live in coastal waters off the Eastern United States, have experienced drastic population declines over the past several decades. Understanding how these sharks move and interact could help biologists better conserve this species and determine how vulnerable they are to human activities. During summer, the sharks congregate in the shallow waters of Delaware Bay but are highly migratory, travelling as far south as the Carolinas and Florida during the winter and early spring.
This action expands on the 2022 closure of the Guadalupe Island Biosphere Reserve by the National Commission of Natural Protected Areas (CONANP), the federal agency tasked with managing Mexico’s protected natural areas.
They also closed the island to cage diving in 2021 and the pandemic closed down operations in 2020.
Scientists with the New England Aquarium found that nurse sharks, Ginglymostoma cirratum, returned to the waters off the Dry Tortugas, 70 miles (113km) from Key West, to mate for up to 28 years. The Dry Tortugas has been known as a courtship and mating site for nurse sharks since 1895.
A 30-year (1992–2021) study documented long-term site fidelity to this area, with data from 137 adult sharks.
