While swimmers and boaters don’t have to fear sharks or giant squid in the Great Lakes watershed, invasive fish the size of large dogs lurk in the freshwater. Invasive carp have wreaked havoc on the ecosystem for over a century, but officials have hit a milestone worth celebrating in the fight against these mega fish.
In the past 15 years, wildlife officials have removed 50 million pounds of invasive carp from the Illinois River. That’s equivalent to roughly 5,000 elephants. The removal is part of a broader and coordinated effort to protect the rivers and lakes from this non native species.
Currently, four species of invasive carp cause harm in the Great Lakes and beyond—bighead carp (Hypophthalmichthys nobilis), silver carp (Hypophthalmichthys molitrix), black carp (Mylopharyngodon piceus), and grass carp (Ctenopharyngodon idella).
According to the Great Lakes Fishery Commission, all four species were imported to North America to help with pest control in aquaculture facilities in the 1970s. The carp escaped confinement in only 10 years, and have spread to the Mississippi River basin and other large rivers, including the Missouri and Illinois.
Each of the four invasive carp species can weigh more than 100 pounds and grow to four feet from tip to tail. Bighead carp and silver carp generally feed on the tiny plankton in the water, while grass carp eats rooted plants in shallow water, and black carp feed primarily on mollusks and snails.
“They consume so much food and can exist in such great numbers that they can really reduce the amount of [resources] for resident species of fish,” Peter Alsip, an ecologist with the NOAA Great Lakes Environmental Research Lab told Popular Science in 2024. “They can have indirect effects on the whole ecosystem because [silver carp] are consuming phytoplankton and zooplankton, which are essentially the base of the food web.”
Once inside a watershed, they can reproduce rapidly and compete with native fish species for resources. In areas where invasive carp are abundant, they have harmed other fish species and interfered with commercial and recreational fishing, according to the United States Fish & Wildlife Service (USFWS). They can also pose a danger to humans, as the giant fish can jump out of the lake and hit unsuspecting boaters.
Carp eradication measures have been active for over 100 years. These efforts include targeted mass removal efforts, developing barriers to block or impede their movement, and ongoing monitoring.
The 50 million pounds of fish removed from the Illinois River were part of a program focusing on the northern part of the river about 50 miles from Lake Michigan. The removal project is designed to suppress the mostly adult populations of carp living in the area, by limiting their ability to reproduce and reduce their migration upstream towards the Electric Dispersal Barrier System. Located about 37 miles from Lake Michigan, this electric barrier is designed to deter their movement through the Chicago area. It is one of the main tools wildlife officials are using to keep them from further entering the Great Lakes through the Illinois River. Another program in the Illinois River offers fish harvest incentives to commercial fishers in the river’s lower 240 miles.
“The more invasive carp we remove, the more we reduce their harmful impacts and the risk of them reaching Lake Michigan,” the USFWS wrote on Facebook. “Thanks to these and other efforts to monitor our waters and prevent the spread of invasive carp, Illinois and more than two dozen partners are safeguarding some of our most prized native fisheries, and the Great Lakes regional economy.”
The post 50 million pounds of invasive fish removed from Illinois River appeared first on Popular Science.
Field notebooks from the late Richard Köhler allowed researchers to finally catalog a remarkable fossil tarpon from Aotearoa New Zealand. Recently disclosed notebooks from a late paleontologist supplied the missing details researchers needed to complete their study of a “remarkable” fossil found nearly 30 years ago. Dr. Richard Köhler discovered the fossil fish in 1999 [...]
Routine checkups for humans are usually straightforward. The doctor tells you what to do, and unless you’re a squirming baby or terrified of needles, you pretty much follow instructions.
But what happens when the patient is a giant yellow-orange eel with sharp teeth? Things get a bit slippery. At the New England Aquarium, experts need to follow a complicated process in order to get Thomas, a green moray eel (Gymnothorax funebris), ready for his yearly checkup.
The first step consists of retrieving Thomas from the aquarium’s giant ocean tank. Divers get him into a plastic barrel.Thomas and the barrel are then submerged into a different water tank with powdered anesthetic water, Melissa Joblon, New England Aquarium’s director of animal health, tells Popular Science.
“We have to be really cautious to make sure that he’s fully anesthetized before we handle him because they can be dangerous,” she adds, “and they’re very slippery and can kind of slither away if we’re not really careful.”
Once Thomas is essentially knocked out, the team lifts him from his sedation bin and onto a rack. They then flush water—with more of the anesthesia agent—which allows him to continue breathing.
The medical exam is preventative care, meaning the team is on the lookout for any health issues to catch them before they become serious. The session includes a physical exam, bloodwork, a full ultrasound, and an electrocardiogram. The team is essentially investigating the eel’s outsides and insides.
“We do full routine annual exams on the majority of the animals that live at the aquarium, similar to bringing your cat or dog to a vet once a year,” Joblon explains.
Thomas is probably 18 to 21 years old, but he was a juvenile when the New England Aquarium took him in. A pet owner donated him after wisely deciding that they couldn’t care for the eel anymore—Thomas was becoming too big. Green moray eels are, after all, among the largest morays—they can be eight feet long.
Here’s to making sure Thomas eels good.
The post Thomas the moray eel goes to the doctor appeared first on Popular Science.
Paleontologists in Argentina have identified a previously unknown species of unenlagiid dinosaur that stalked freshwater wetlands during the Late Cretaceous epoch, adding to evidence that some dinosaurs specialized in catching fish.
The post New Dinosaur Species from Argentina May Have Specialized in Catching Fish appeared first on Sci.News: Breaking Science News.
A marine biologist studying the photophores of a bioluminescent fish species found needle-shaped guanine crystals that scatter and redirect light instead of merely reflecting it, a discovery that could inspire more efficient biomedical and optical devices.
The post Bioluminescent Deep-Sea Fish Use Crystal ‘Prisms’ to Recycle Their Own Glow appeared first on Sci.News: Breaking Science News.
These ancient fish lineages survived mass extinctions, ice ages, and evolutionary upheaval.
I spend more time today than ever before interacting with terminal windows, which is something I don't think Past Me would have believed in the early '90s. Back then, poor MS-DOS was the staid whipping boy of the industry, and at least on the consumer side, graphical environments like Windows (and maybe even odder creatures like AmigaOS) seemed poised to stamp the command line into oblivion, leaving text interfaces behind as we all blasted into the ooey-GUI future.
As it turns out, though, the command line is still the best tool for some jobs—many jobs, in fact. I read a wise post some years ago (probably on Slashdot) arguing that a mouse-driven point-and-click interface essentially reduces the user to pointing at something on the screen and grunting, "DO! DO THAT!" at the computer. (The rise of right-click context menus adds the ability for the user to also grunt "MORE THINGS!" but doesn't otherwise add vocabulary.)
The command line, by contrast, gives the user the opportunity to precisely tell the computer what they want done, using words instead of one or two gestalts that the computer must interpret based on context.
© Aurich Lawson | Getty Images
Login