Lemon Shark in black and white

Sharks

Shark Angels Announce FinRaiser Trivia Night

Join the Angels for a fun filled sharky event where you can test your shark knowledge and win prizes including a week long SCUBA liveaboard adventure!

When: Wed July 14th at 4pm PDT/ 7pm EDT

How: Buy a ticket $15 (donation) to join us via Zoom. Once you buy a ticket you will receive a Zoom link to play. Link to registration page: https://sharkangels.kindful.com/e/finraiser-trivia-night-

Prizes

Sharks can navigate via Earth's magnetic field

Since at least the 1970s, researchers have suspected that the elasmobranchs—a group of fish containing sharks, rays, skates, and sawfish—can detect magnetic fields. But up till now, no one had shown that sharks use the fields to locate themselves or navigate.

By exposing sharks to certain magnetic cue, researchers from Florida State University have now managed to demonstrate not only that sharks have an ability to detect Earth’s magnetic field but moreover that they are able to use it to travel long distances with accuracy.

Fresh shark fins drying on sidewalk
(File photo) Fresh shark fins drying on sidewalk

Maldives backpaddles after outcry over lifting shark fishing ban

Shark fishing was completely banned in the Maldives in 2010 so when the country announced plans to discuss legalising the practice again, it created a massive backlash from the international community.

Sharks have always been a valuable tourist attraction in the small island nation and the declining status of shark fisheries, exacerbated by unresolved conflicts with other stakeholders led to the declaration of total shark fishing ban in 2010. With the shark fishing ban in place, sharks are now caught as bycatch in the Maldivian fisheries.

Researchers conclude the northward range shift demonstrates the young white sharks are being subjected to a loss of suitable thermal habitat

Climate change shifts the range of white sharks

Researchers conclude the northward range shift demonstrates water temperatures within their preferred temperature range of juvenile white sharks are becoming harder to find.

The animals have historically remained in warmer waters in the southern California Current; Between 1982 and 2013, the northernmost edge of the juveniles' range was located near Santa Barbara (34° N).

The Port Jackson (Heterodontus portusjacksoni) shark is a benthic, buccal pumping species that remain motionless for extended periods of time.

Do Sharks Sleep?

Sleep is ubiquitous across the animal kingdom but despite anecdotal reports of sleep-like behaviour in nurse sharks and other seafloor-dwelling species, the question of whether sharks actually sleep has been intensely debated but remains unknown. A key criterion for separating sleep from other quiescent states is an increased arousal threshold. True sleep is characterised by a lack of movement that can be rapidly reversed and a decreased awareness of surroundings.

The Caribbean reef shark (Carcharhinus perezi) is the most commonly encountered reef shark in the Caribbean Sea.

Reef sharks prefer small meals

Researchers from James Cook University's ARC Center of Excellence for Coral Reef Studies examined stomach contents of reef sharks and conducted chemical analyses of shark body tissue to find out what they had been eating.  

Somewhat surprisingly after pumping sharks' stomachs to identify the contents of the last meal, the most common thing to find was in fact, nothing. "These results suggest that reef sharks eat small meals infrequently and opportunistically," Lead author, Dr Ashley Frisch said.

Appeal to Shark Lovers!

The paper presents the reasons why large predators of great ecological importance cannot supply the rising demand for shark fins, which is driven by profits that rival the drug trade and involves the fisheries of nations around the globe. They have essentially run out of fish so are targeting sharks now that the shark fin trade has made them valuable.

Sharks at risk from quest to develop vaccine against corona virus

Development of a vaccine against Covid-19 could come at the expense of sharks, researchers warn; A key ingredient used in vaccines to enhance immune response and increase effectiveness, squalene — an oily substance found in plants and even human skin — is particularly concentrated in shark livers.

Salmon Sharks of Alaska

Salmon sharks lack a nictitating membrane, so their eyes can be seen following a subject, Port Fidalgo, Alaska, USA. Photo by Jennifer Idol.
Salmon sharks lack a nictitating membrane, so their eyes can be seen following a subject, Port Fidalgo, Alaska, USA. Photo by Jennifer Idol.

Sharks elicit strong emotions, be it the thrill of a planned encounter underwater or fear propelled by social media and lack of information. Of the more than 400 species of sharks, it is the small family of mackerel sharks that is most iconic. These sharks prompted me to share why one of them, the salmon shark, is an especially remarkable species.