Every year Havets Hus release their home-bred small spotted red sharks into the Gullmarn fjord. Some years, also Thornbacked rays and cod. Here we will tell you a little more about our shark release.
Shark release is a part of the work of Havets Hus to conserve life in the ocean, which is also done by disseminating information on different species and their importance, biological diversity and about threats to the marine environment.
Read more about the conservation project here.
On this page you can track the sharks’ journey from egg to release into the sea.
Below there is a film of an earlier ray and shark release.
It begins with 55 minutes of the ocean then the release begins.
Located sharks
We have released circa 200 sharks since 2003, some have been recovered, here you can see which and where we found them:
Shark mating
Sharks have internal fertilisation, and mating can get quite wild. It begins with the male swimming up to the female and biting her. He then pulls her down to the bottom where he wraps himself around her. Sharks have two penises, and he fertilises her with one of them. Mating takes from fifteen minutes to an hour. Generally, it takes place in the afternoon or evening, at least in the large aquarium within Havets Hus.
Shark eggs
The shark embryo grows in an egg capsule which hangs in long curly threads on, for example, seaweed or ropes in the sea. It takes up to nine months for the shark to develop and during this time it gets nutrition from the yolk sac in the egg. The small spotted red shark lays quite a lot of eggs and survival in captivity is good.
This is what a shark egg looks like:
Baby sharks
When the yolk sac is empty the young unfold and swim out of the capsule. The newly born young are light in colour as the distinctive spotting develops later. The young grow at approximately ten centimetres a year, dependant on the temperature of the water. To begin with the young get finely chopped shelled prawns to eat. When they are a little bigger, they get prawns, mussels, fish and bits of octopus. For most of the time the sharks lie on the bottom and swim only occasionally. But when they get food they are suddenly very active!
Small spotted red shark’s young
Sharks about to be released
Sharks that are born inside Havets Hus are mostly released into the sea. Before that the sharks are weighed and measured. They are also tagged with a number on a piece of green plastic. If later someone happens to catch one of our sharks, they can read the number on the plastic tag and report back to us. Then the shark must be returned to the sea again as they are protected and catching them in Sweden is forbidden. Thanks to the tagging we know that our sharks swim along both the Swedish and Norwegian coasts and can live to at least 14 years of age.
Measuring a small spotted red shark.
Newly tagged small spotted red shark.
What can we do to improve the shark’s situation?
– Do not eat shark! Shark fins are considered a delicacy in many places in the world and are even served in Sweden. They are often offered under a name other than shark and so one must be aware.
– When you eat normal fish, eat eco-labelled. That way you reduce the risk that sharks have been caught unnecessarily as a result of bad fishing practice.
– Support the world’s sharks – many organisations work for shark survival and marine conservation. Among other things one can be a marine sponsor at the World Wildlife Fund WWF.
– Be a Citizen Scientist. If you find a small spotted red shark contact Havets Hus with the tag number, the length of the shark and where it was found. Please also send a photo of the shark. Other sharks can be reported to the species observation portal www.artportalen.se.
-You can also tell others why Havets Hus releases sharks and about the shark’s situation in the ocean.
– Do not eat shark! Shark fins are considered a delicacy in many places in the world and are even served in Sweden. They are often offered under a name other than shark and so one must be aware.
– When you eat normal fish, eat eco-labelled. That way you reduce the risk that sharks have been caught unnecessarily as a result of bad fishing practice.
– Support the world’s sharks – many organisations work for shark survival and marine conservation. Among other things one can be a marine sponsor at the World Wildlife Fund WWF.
– Be a Citizen Scientist. If you find a small spotted red shark contact Havets Hus with the tag number, the length of the shark and where it was found. Please also send a photo of the shark. Other sharks can be reported to the species observation portal www.artportalen.se.
-You can also tell others why Havets Hus releases sharks and about the shark’s situation in the ocean.
What can we do to improve the situation in the ocean?
– Reduce the amount of plastic in the sea by recycling your waste and never leaving rubbish anywhere.
– Shop less frequently and choose natural materials rather than synthetics.
– Launder less often, air out and dry instead.
– Choose products without microplastics (avoid polyethylene, polypropylene, polyethylene terephthalate, polymethyl methacrylate and nylon).
– Encourage your municipality to lay out real grass instead of artificial grass pitches, and drive on stud-free tyres.
– To reduce global warming and acidification of the oceans one can choose environmentally-friendly transport and avoid unnecessary long journeys.
– Choose local and environmentally approved goods and electricity.
Start small because this also impacts the large. Together we can help ourselves by helping the oceans. After all the oxygen for every second breath we take comes from the sea.
Havets Hus and WWF
Havets Hus collaborates with the WWF which supports measures that further develop the work with breeding and release as well as dissemination of information concerning the predicament of the world’s sharks.