Isn’t Science Great? Biologists Collect Unborn Baby Sharks and Raise Them 

Isn’t Science Great? Biologists Collect Unborn Baby Sharks and Raise Them 

Whenever I see dead sharks in a fish market, I sigh because I feel so helpless. But apparently there’s still hope, provided that the sharks are female and haven’t been dead that long. The hope is not about reviving the sharks, it’s about saving what’s inside them. 

Greg Nowell is a biologist and a founder of Sharklab-Malta, one of at least three organizations around the Mediterranean that nursemaids several species of sharks and their close relatives, skates. 

Every early morning, Nowell tries to identify females and runs his fingers along the belly of these marine creatures. If he finds the ones carrying eggs, he takes them. Even though the eggs may look beyond hope, they’re actually quietly thrumming with life. 

After, he brings the eggs back to his office and his lab, trying to give each unborn shark another shot at living. By collecting and raising babies this way, Nowell and his team at Sharklab-Malta wants to make a small difference in a world that hasn’t been kind to sharks. 

When these eggs hatch, the young sharks have two roles to fill. First, they’ll help educate kids and adults to see that sharks are worth protecting. Second, they’ll act as guinea pigs. It sounds bad, but they’re important to help refine standardized procedures for raising babies like them. 

Thanks to Nowell’s experiments, scientists working with these eggs may be ready to adopt these methods for other species of sharks and skates in the future. 

Saving shark babies 

Around 30 to 40% of sharks and all skate species reproduce using egg case. This pouch serves like an external womb, packed with nutritious yolk that feeds the young shark as it grows. 

Unfortunately, not all shark species use this egg case method for reproduction. So, the scientists hope that the techniques involving egg case developed today could help species currently facing a much greater risk of extinction.  

Nowell said, “Some people ask, ‘If you’re taking these eggs and recovering sharks, are you saving the population?’ And we’re not.  

“If we can put two back for every one [fished], fantastic. But ultimately what this whole process enabled us to do was look at a methodology, and develop a method that can be used anywhere in the world.” 

Should there be any eggs from fishermen, Jaime Penadés Suay has learned the hard way that one shouldn’t throw or toss the babies or eggs.  

The marine biologist stated that unhatched sharks within their egg cases are actually tough little creatures. Being snarled on fishing nets and seaweed? Not a problem. Sitting for hours in a plastic bottle on a fishing trawler without refrigeration? Piece of cake.  

Fun fact: the one without refrigeration was a bit of an accidental discovery. Fishermen were given buckets of ice for the eggs, but they used them for beer instead.  

But one thing’s for sure, they don’t survive impact. Penadés Suay learned when a fisherman tossed the eggs to his colleague Pablo García Salinas, that was the end. 

Penadés Suay said, “Those eggs never developed. We tested maximum velocity, and it’s not good.” 

Even so, García Salinas and Penadés Suay have raised and released over 120 small-spotted catsharks out of 150 viable egg cases in less than two years.  

Founding organization and working with the locals 

The eggs were collected directly by local fishermen who work under Associació Lamna, a small NGO that García Salinas and Penadés Suay  cofounded in Spain to promote shark conservation and research. 

Apparently, the two marine biologists had found that people around them, including the ones in marine sciences field, are not too concerned about sharks. Penadés Suay said that Spain has a national program to respond to stranded cetaceans and sea turtles, but not stranded sharks. 

So, they founded Lamna, hoping to show some love to sharks and spread it to other people. It kind of works, because now whenever there’s a stranded shark or ray, the local government calls Lamna to investigate its cause of death. 

“They still only care on paper about cetaceans and marine turtles—we haven’t changed the law. We’ve been doing this assistance to stranding scenes since 2012, but by creating this NGO the local government had to recognize our work and to acknowledge this problem,” he said. 


Mediterranean people love their fish, which is nutritious, but maybe a bit too much. According to a 2008 research, large shark populations in the Mediterranean had declined by more than 97% over the last 200 years. 

Sharks, rays, and skates which used to populate the Mediterranean are now so scarce, exacerbated by human consumption. Conservation efforts are aplenty, that’s for sure. But maybe growing eggs are quite new. 

Nowell was reportedly the first to do that. In late 2011, he was conducting a survey of the different shark species sold at the Valletta market. Something caught his eye then: an egg case poking out of the cloaca of a whole shark for sale. 

He wasn’t thinking much but he took the egg case home, watching it for two months. To his surprise, it matured within the walls of his home aquarium. And when he shone a light through the egg case, there it was: a moving, pulsing embryo beginning to grow. 

“That was when the thoughts started. Prior to this, during the [market’s] cleaning process, anything that couldn’t be sold would just be thrown away. Our opportunity is giving a chance to something that would simply be discarded,” said Nowell. 

And since then, he began to experiment more on egg cases and he eventually managed to grow baby sharks. 

Comments from a skeptic 

A professor of marine biodiversity and conservation and leader of the IUCN’s Global Shark Trends Project Nick Dulvy isn’t too convinced about these efforts. 

“You don’t want to be seen punching down at people just doing their best. But when people say they’re rearing baby skates or baby sharks and putting them into the ocean, they’re just feeding wild fish,” Dulvy said. 

According to Dulvy, like most fish species, any shark or skate contributes little to the growth of a population as a whole. During its lifespan, a shark will produce hundreds of eggs rather than investing energy in an individual egg. 

Basically, every egg is a bit like a lottery ticket, with a slim chance of cashing out as an adult shark. Therefore, Dulvy argues that the value is not in each baby shark, it’s in the adult that’s capable of making them. 

Moreover, sharks can take years before they are able to start reproducing. Some species need four decades before they’re fully mature. What Dulvy suggests is to protect reproductive-age adults, like science-based catch limits. According to him, that’ll leave the greatest impact. 

Dulvy added, “The right question to ask is, given that there are few adults in the population, what’s the best conservation activity I should be taking? 

“Should I be focusing my efforts on reducing mortality on adults or rehabilitating juveniles? Your effort is always better spent focusing on the subadults and adults.” 

There’s a glimmer of hope though 

Even though Dulvy may seem harsh about the egg case rearing projects, he doesn’t dismiss them completely. There are situations that may need growing shark egg cases. 

Dulvy and other shark researchers highlighted the international effort to restore the wild population of zebra sharks, an endangered species native to the Indo-Pacific. 

Rather than collecting them from the wild, egg cases for the Stegostoma tigrinum Augmentation and Recovery (StAR) project will come from adults bred in zoos and aquariums around the world. 

Since these sharks are a popular attraction in such institutions (and many have their own successful breeding programs), the species may be more populous in captivity than it is in the wild. 

So according to Dulvy, these projects may work, but not in the wild. And despite his criticism, Dulvy doesn’t want to bash these projects at all. 

“It’s really churlish to pour scorn on hopeful activities. With climate change, overfishing, everything—everybody’s looking for a little thing they can do.” 

And he’s right in that sense. Plus, I personally think that at least the human-grown baby sharks can always provide education and awareness to kids and adults so that we humans care more about them in the future. 



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