15 Years of Data Sheds Light on Nasty Stuff Hitching a Ride in Whales and Dolphins

So, get this: whales and dolphins, right? They’re out there munching on their seafood platter, snagging fish, squid, and the occasional crab, which is how they get all their important nutrients. But here’s the catch – while they’re feasting, they’re also gulping down some nasty heavy metals that shouldn’t be on the menu.

We’ve bumped into some of these oceanic pals that got stranded along the Southeast coast, and they’re packing more toxins than a villain in a superhero flick. Keeping tabs on these toxin levels is super important because these sea creatures are like the canaries in the coal mine for our oceans. Plus, their health could be a sneak peek into our own well-being because, guess what, we’re all in this together.

But let’s dive a little deeper, shall we? We’re not just talking about a couple of mercury fillings here. We’re talking about a bewildering mix of elements these marine critters are packing in different parts of their bodies. So, the brainiacs over at Florida Atlantic University’s Harbor Branch Oceanographic Institute teamed up with some science superheroes to get the scoop. They rolled up their sleeves and sifted through all sorts of samples from these majestic sea floofs—think blubber, kidneys, liver, muscles, skin, and even their poo. Yup, nothing was off-limits. They went full CSI on 90 of these ocean dwellers that had landed up on the beaches of Georgia and Florida between ’07 and ’21, all to figure out who’s got what and where. Spoiler alert: it wasn’t just sea salt and sunshine.

The science squad examined 319 samples from nine different swimmers of the deep – we’re talking a VIP list featuring dolphins and their whale cousins. They were on a scavenger hunt for a cocktail of elements – seven goodies that are like vitamins to these creatures (think cobalt, copper, iron, manganese, molybdenum, selenium, zinc) and five baddies that are no one’s friends (cue the ominous music for arsenic, cadmium, lead, mercury, thallium). Now, these marine VIPs weren’t picky eaters; all of them were chowing down on a similar diet of squiggly cephalopods and various fishy delights, right at the top of the food chain where the big guns dine.

Alright, so when the science team’s findings hit the presses in Cell Press: Heliyon, it was like unboxing the latest tech gadget, but instead of wires and screens, we got some heavy metal deets on our ocean buddies. The Risso’s dolphins—or as we like to call ’em, Grampus griseus—and the short-finned pilot whales, those Globicephala macrorhynchus rockstars, were totally owning it on the heavy metal charts, and not in the cool, head-banging kind of way. They had the highest median concentrations of those bad boy elements—mercury, cadmium, and lead—just swimming in their systems. Meanwhile, the dwarf sperm whales, those petite Kogia sima dudes, were chilling at the other end of the spectrum with way lower levels. It’s like they had backstage passes to the cleaner parts of the ocean concert while others were stuck in the mosh pit.

Check it out – the ocean’s tiny rockstars, the adult pygmy, and the dwarf sperm whales, are kinda like the grizzled veterans of the sea. But here’s a sobering backstage fact: the crew that washed up between 2019 and 2021 were totin’ more of those heavy metal vibes in their systems – we’re talking a whole mixtape of arsenic, copper, iron, lead, manganese, selenium, thallium, and zinc – than the ones that belly flopped ashore in the earlier 2010 to 2018 tours. Yeah, you got that right. It seems these oceanic critters might be dodging more toxic bullets as the years roll by, tipping us off to a gnarly trend of them swimming in increasingly sketchy waters.

Annie Page, D.V.M., Ph.D., senior author, an associate research professor and clinical veterinarian, FAU Harbor Branch, said “When we separated phylogenetic groups into age classes and compared median concentrations of heavy metals in specific tissue types between adult specimens of species, we found some interesting trends.”  

And you know what’s wild? When they hit the lab to play detective with the poops from our whale pals, they discovered it’s like striking gold—well, if gold was actually a mix of heavy metals that you definitely don’t wanna make jewelry out of. Turns out, the whale doo-doo was a treasure trove, revealing a bunch of elements they probably didn’t have on their dietary plan. It’s kinda brilliant, because snatching up these samples is a whole lot less hassle for everyone involved—no whale-size needles necessary.

But hey, it wasn’t just about the potty analysis. When the scientists rummaged through the other bits and pieces, like the liver—the command center for detoxing—they found it jam-packed with its own metal festival featuring iron, mercury, and some other metal groupies. The same goes for the kidneys, where cadmium was having a solo party, while the skin was flaunting a zinc VIP badge. Copper, arsenic, and lead turned out to be social butterflies, fluttering between the liver and kidneys. So yeah, it’s like every organ in these majestic sea creatures was vibing to its own heavy metal tune.

Diving into the deets, it looks like the dwarf sperm whales are the zen masters of the sea when it comes to dodging the heavy metal scene — we’re talking about mercury and cadmium, the notorious moshers of the marine world. These cool creatures had the tiniest amount of these toxic groupies lurking in the usual fan spots: liver, kidneys, blubber, and muscles, with their skin rocking the lowest mercury levels and their livers practically lead-free zones. Mercury, that sneaky headliner, is super clingy in ocean circles and tends to crash more parties as it moves up the food chain, piling into organs like uninvited guests. Our cetacean buddies catch these toxic vibes by munching on prey that’s already jamming out to these heavy metals, making their insides unintentional storage rooms for these unwelcome guests.

“Exposure to heavy metal contaminants can result in oxidative stress, which can impair protein function, damage DNA and disrupt membrane lipids,” said Page. “Heavy metal exposure has been linked to degenerative heart disease, immunodeficiency and increased parasite infestations, among other disease risks.”

Those lab coats behind the scenes aren’t just digging through all this sea life jazz for kicks. Nope, they’ve laid down some serious baseline beats that are key to tuning into how all these trace elements are cramping our whale and dolphin buddies’ style. By studying the build-up of these riffs in their bods, they can jam out to the bigger picture of how these metals are messing with our finned friends’ inner workings. It’s like the ultimate backstage pass to understanding the health of our oceans and the rockstars that call it home. The data’s like the first track on a mixtape that’s gonna blast out some brainy breakthroughs about the unexpected mosh pits happening inside these marine mammals.

Page said, “Because tissue concentrations of heavy metal contaminants also vary based on an individual animal’s sex, age class, trophic level and location, among other factors, it is important to first establish baseline values and then continue to monitor cetacean populations for exposure to these toxicants.”

So look who we got lined up in our oceanic gig, the who’s who of the deep blue: those compact rockers, the pygmy sperm whales (Kogia breviceps), the elusive dwarf sperm whales just gliding under the radar, and the enigmatic Gervais’ beaked whales (Mesoplodon europaeus)—truly the indie artists of cetaceans. Then, strutting in with their trademark clicks and whistles, are the Risso’s dolphins, always ready to photobomb a deep-sea selfie. Sharing the stage, the short-finned pilot whales bring their tight-knit family vibes, followed by the grandiose sperm whales (Physeter macrocephalus), like the headlining act with their astounding deep dives. The melon-headed whales (Peponocephala electra) show up with their squad goals, just added funk to the mix. And for a touch of rarities, we got a Blainville’s beaked whale (Mesoplodon densirostris) and a false killer whale (Pseudorca crassidens) dropping their unique beats into the ocean mixtape. It’s a lineup that’s as eclectic as a comic con panel, each species jamming out in their own legendary style.

Alright, so let’s give some props to the squad behind this rad research we’re jawing about. The dream team is like a supergroup featuring brainiacs from FAU Harbor Branch, those sharp cadets from the U.S. Coast Guard Academy, the smarty pants from the University of Alabama at Birmingham, the eco-warriors over at Hubbs-Sea World Research Institute, the dynamos from Blue World and Florida Fish & Wildlife Conservation Commissions—yeah, the heavy hitters in marine research. Shoutout to the Georgia Department of Natural Resources for keeping it real with the local insights.

And yo, let’s not forget the VIPs who poured some treasure into the treasure chest that funded this shindig. We’re talking ’bout the Florida State License Plate Program with “Protect Wild Dolphins” and “Protect Florida Whales” grants—cool license plates spinning up some funds. Big-ups to the Harbor Branch Oceanographic Institute Foundation for making it rain, the Link Foundation for linking arms with the cause, and the John H. Prescott Marine Mammal Rescue Assistance Grant for tossing a lifeline. Props to the SeaWorld Busch Gardens Conservation Fund for keeping the party animal-friendly, Discover Florida Ocean’s License Plate for unlocking the ocean’s secrets, and the Brevard County’s tourism bigwigs for kicking in a few bucks to the pot. Together, it’s like they’ve created the ultimate festival sponsorship to rock the boat on marine health.