The tragic story of Lulu, a beloved orca found dead and entangled in fishing gear last year, has taken a turn for the worse.
"The levels of PCB contamination in Lulu were incredibly high, surprisingly so," Dr. Andrew Brownlow, head of the Scottish Marine Animal Stranding Scheme and veterinary pathologist at Scotland's Rural College, told BBC News. "They were 20 times higher than the safe level that we would expect for cetaceans to be able to manage."
"The threshold where we think that there is some form of physiological effect caused by PCBs is around 20-40mg/kg stored within the tissues," Brownlow said.
But Lulu had a level of PCBs of 957mg/kg, putting her as "one of the most contaminated animals on the planet in terms of PCB burden," Brownlow said.
Lulu was estimated to be at least 20 years old when she died, which is why she might have built up such high PCB levels.
As one of the last remaining killer whales in the UK, Lulu's death has raised fears of extinction for the population. There may be only eight remaining individuals in the killer whale's pod.
The long-term survivability of this group of UK killer whales is now being questioned, as the remaining animals might be similarly contaminated.
Lulu was found dead on Jan. 3, 2016 on the Scottish island of Tiree with deep lesions on her body. After a necropsy was performed, experts concluded that Lulu had been "chronically entangled" in abandoned fishing gear for several days and likely drowned from entanglement.
But it was suggested that PCBs could have contributed to her demise since the chemicals are known to affect the brain.
"It is potentially plausible that there was some effect of the PCBs that was in some way debilitating her so she wasn't strong enough or even aware enough to deal with this entanglement (in fishing line)," Brownlow said. "We very rarely see entanglement in killer whales—actually this is one of the first cases we have documented."
The chemicals can also cause infertility and could explain why Lulu never reproduced.
"That's certainly what we found in the case of Lulu," Brownlow explained. "Having examined her ovaries, there was no evidence that she had ever been reproductively active or had ever had a calf."
Scientists have not observed any calves born the UK's waters in 25 years.
"Lulu's apparent infertility is an ominous finding—with no new animals being born, it is now looking increasingly likely that this small group will eventually go extinct," Brownlow told The Guardian.
By Aaron W Hunter
A chance discovery of a beautifully preserved fossil in the desert landscape of Morocco has solved one of the great mysteries of biology and paleontology: how starfish evolved their arms.
The Pompeii of palaeontology. Aaron Hunter, Author provided<h2></h2><p>Although starfish might appear very robust animals, they are typically made up of lots of hard parts attached by ligaments and soft tissue which, upon death, quickly degrade. This means we rely on places like the Fezouata formations to provide snapshots of their evolution.</p><p>The starfish fossil record is patchy, especially at the critical time when many of these animal groups first appeared. Sorting out how each of the various types of ancient starfish relate to each other is like putting a puzzle together when many of the parts are missing.</p><h2>The Oldest Starfish</h2><p><em><a href="https://www.biorxiv.org/content/10.1101/216101v1.full.pdf" target="_blank" rel="noopener noreferrer">Cantabrigiaster</a></em> is the most primitive starfish-like animal to be discovered in the fossil record. It was discovered in 2003, but it has taken over 17 years to work out its true significance.</p><p>What makes <em>Cantabrigiaster</em> unique is that it lacks almost all the characteristics we find in brittle stars and starfish.</p><p>Starfish and brittle stars belong to the family Asterozoa. Their ancestors, the Somasteroids were especially fragile - before <em>Cantabrigiaster</em> we only had a handful of specimens. The celebrated Moroccan paleontologist Mohamed <a href="https://doi.org/10.1016/j.palaeo.2016.06.041" target="_blank" rel="noopener noreferrer">Ben Moula</a> and his local team was instrumental in discovering <a href="https://www.sciencedirect.com/science/article/abs/pii/S0031018216302334?via%3Dihub" target="_blank" rel="noopener noreferrer">these amazing fossils</a> near the town of Zagora, in Morocco.</p><h2>The Breakthrough</h2><p>Our breakthrough moment came when I compared the arms of <em>Cantabrigiaster</em> with those of modern sea lilles, filter feeders with long feathery arms that tend to be attached to the sea floor by a stem or stalk.</p><p>The striking similarity between these modern filter feeders and the ancient starfish led our team from the University of Cambridge and Harvard University to create a new analysis. We applied a biological model to the features of all the current early Asterozoa fossils in existence, along with a sample of their closest relatives.</p>
Cantabrigiaster is the most primitive starfish-like animal to be discovered in the fossil record. Aaron Hunter, Author provided<p>Our results demonstrate <em>Cantabrigiaster</em> is the most primitive of all the Asterozoa, and most likely evolved from ancient animals called crinoids that lived 250 million years before dinosaurs. The five arms of starfish are a relic left over from these ancestors. In the case of <em>Cantabrigiaster</em>, and its starfish descendants, it evolved by flipping upside-down so its arms are face down on the sediment to feed.</p><p>Although we sampled a relatively small numbers of those ancestors, one of the unexpected outcomes was it provided an idea of how they could be related to each other. Paleontologists studying echinoderms are often lost in detail as all the different groups are so radically different from each other, so it is hard to tell which evolved first.</p>
EcoWatch Daily Newsletter
- Biden Reaffirms Commitment to Rejoining Paris Agreement ... ›
- Biden Likely Plans to Cancel Keystone XL Pipeline on Day One ... ›
- Joe Biden Appoints Climate Crisis Team - EcoWatch ›
Listen:<iframe style="border: none" src="//html5-player.libsyn.com/embed/episode/id/17278520/height/45/theme/standard/thumbnail/yes/direction/backward/" height="45" width="100%" scrolling="no" allowfullscreen webkitallowfullscreen mozallowfullscreen oallowfullscreen msallowfullscreen></iframe><p><em>Reposted with permission from </em><em><a href="https://yaleclimateconnections.org/2021/01/college-course-teaches-students-how-to-be-climate-leaders/" target="_blank" rel="noopener noreferrer">Yale Climate Connections</a>.</em></p>
By Daniel Raichel
Industry would have us believe that pesticides help sustain food production — a necessary chemical trade-off for keeping harmful bugs at bay and ensuring we have enough to eat. But the data often tell a different story—particularly in the case of neonicotinoid pesticides, also known as neonics.
- Bees Face 'a Perfect Storm' — Parasites, Air Pollution and Other ... ›
- European Top Court Upholds French Ban on Bee-Harming Pesticides ›
- UK Allows Emergency Use of Bee-Killing Pesticide - EcoWatch ›
By Andrea Germanos
Fed up with "empty promises" from world leaders, a dozen youth activists on Wednesday demanded newly sworn-in President Joe Biden and Vice President Kamala Harris take swift and bold climate action — even more far-reaching than promised on the campaign trail — stating that their "present and future depend on the actions your government takes within the next four years."
- Stories From the Youth Climate Movement in the Global South ... ›
- Young Climate Leaders Conclude Mock COP26 With Calls for ... ›
- Climate Activist Greta Thunberg Endorses Biden in Tweet - EcoWatch ›