Making Waves Weekly: LEDs could prevent shark attacks, orcas are hunting whale sharks, and more…
Plus: 1st of the season.
Sharks, orcas, and whales–oh my! Let’s get to it:
HIGHLIGHTS
Could LEDs keep us safe from great whites?
While great white sharks don’t deserve the reputation that Jaws gave them, it’s not a secret that this particular shark species is at the top of the list regarding unprovoked attacks on humans. Now, researchers think they may have discovered a way to deter great whites humanely: LED lights.
Great white sharks’ most dominant sense is smell—they can sense roughly 1 part of specific matter (such as blood) per 10 billion parts of water, leading to picking up scents a great distance from the original source. However, eyesight does play an essential role during a shark attack. Poor eyesight, not smell, makes sharks mistake surfers and swimmers for seals or turtles.
Researchers have been testing the use of LED lights in deterring sharks, particularly great whites. While a few studies have tested how implementing LEDs could break up the silhouettes sharks associate with food, one study in great white hotspots in South Africa is particularly promising.
During the South Africa study, researchers experimented with towing seal-shaped decoys behind a boat. This is the same sort of method commonly seen on TV in shows like Air Jaws, which can prompt a shark attack and subsequent breach. After using the normal decoys, researchers swapped in decoys wrapped in different LED light configurations. They found that seal decoys that had LED stripes effectively deterred shark attacks.
"It's sort of like an invisibility cloak but with the exception that we are splitting the object, the visual silhouette, into smaller bits," said Professor Nathan Hart, head of Macquarie University's Neurobiology Lab. "It's a complex interaction with the shark's behavior. The lights have to be a certain pattern, a certain brightness."
Who knows? Maybe after a few more years of research, we’ll all be using surfboards lit up with LEDs.
Read more about the studies here.
Orcas are eating whale sharks
Whale sharks have been thought to be on the menu for some orca ecotypes for a while. Researchers have now released evidence proving that orcas feast on these giant fish.
Between 2018 and 2024, orca predation of whale sharks in the Gulf of California was studied and documented. Scientists and members of the public captured unique predation events through images and video. Examining the digital evidence has allowed scientists to identify involved individuals and sense repeated patterns.
In a study released in Frontiers in Marine Science, researchers detail how these attacks are carried out and which individual orcas are repeatedly involved.
“When hunting, all pod members work together, hitting the whale shark to turn it upside down. In that position, the sharks enter a state of tonic immobility and can no longer move voluntarily or escape by going deeper,” explains Erick Higuera Rivas, the study’s senior author and a marine biologist at Conexiones Terramar. “By keeping it under control, the orcas then have greater ease and speed in approaching the pelvic area of the shark and are able to extract organs of nutritional importance for them.”
It has always been theorized, and anecdotal evidence supported the theory, that orcas would take advantage of the food available by attacking large, slow whale sharks. However, this is the first time video and photographic evidence confirms that whale sharks are regularly on the menu for orcas.
Read more about orcas attacking whale sharks here or here.
Getting quiet to count the whales
Our oceans grow noisier every year. The sound of boats and ships traveling through these waters can easily drown out the noise of the natural world in the depths below. Now, to better hear whales, Oregon researchers are trying quieter research tactics.
Researchers associated with Oregon State University and the National Oceanic and Atmospheric Administration Fisheries are deploying three autonomous vehicles known as Seagliders. Gliders can quietly travel long distances through the water while recording data from the surrounding environment. These specific gliders are being deployed for passive acoustic monitoring, a way of tracking noise underwater, to research whales in area waters.
“Passive acoustic monitoring may better detect some whales, for instance. Beaked whales make up a quarter of all cetacean species but dive deep after their squid prey for as long as 2 hours,” explained David Mellinger, a professor at Oregon State University. Mellinger began using gliders like these to record whales 15 years ago.
The team hopes to expand the research from Oregon’s coastal waters and launch a similar project in the coastal waters surrounding the Hawaiian Islands in 2026.
Read more about this research here.
DATA POINT
The fisheries division of the National Oceanic and Atmospheric Administration announced the first sighting of a North Atlantic right whale mother and calf pair this season! The mother is #2413, known as “Nauset,” and they were spotted six miles off Sapelo Island, Georgia. The estimated remaining North Atlantic right whale population is only 370 individuals, so a new baby is cause for celebration. See the photo and read more about these whales here.
ICYMI
SWIMMING ACROSS YOUR SCREEN
Signing off on this week's marine news. See you next week with a new wave of ocean updates!
Kelvey 🌊🦈
P.S. You can send news tips, story ideas, hate mail, and photos of cute ocean creatures to thesaltwaterchronicles@gmail.com.