Help Support EcoWatch
The best of EcoWatch, right in your inbox. Sign up for our email newsletter!
Sydney's Endangered Seahorses Find Protection in Underwater Hotels
By Manuela Callari
It can grow to a maximum of six inches (16 centimeters), change color depending on mood and habitat, and, like all seahorses, the White's seahorse male gestates its young. But this tiny snouted fish is under threat.
White's seahorse, also called the Sydney seahorse, is native to the Pacific waters off Australia's east coast. In recent years, populations have decreased drastically. It and the South African Knysna seahorse are the only two out of around 50 seahorse species to be listed as endangered.
A wild storm season from 2010 to 2013 left the Sydney seahorses' habitat in tatters, wiping out 90% of the population in the area. Several large storms shifted huge volumes of sand, smothering the soft corals, sponges and seagrass they call home.
That's why researchers in Sydney Harbor have built special seahorse hotels to help restore their habitat and encourage would-be White's seahorse dads to fall pregnant.
"There are two things that we're trying to gain from this project," said Robbie McCracken, an aquarist at Sydney Sea Life Aquarium, who's working with researchers from University of Technology Sydney and the New South Wales DPI Fisheries on the program.
"Number one is that we can breed these animals in an aquarium to release them into the wild. And number two is that the seahorse hotels provide a suitable environment for them to live on."
Building an Ocean Seahorse Destination
Seahorses are found in tropical and temperate coastal water worldwide, but are most abundant around Australia, China and the Philippines.
Trade in the tiny creatures is strictly regulated because of their use in traditional medicine, aquariums and their sale as dried curios. But because they are poor swimmers and cannot easily move elsewhere, habitat loss is a particular threat for these curious animals.
Seahorses wrap their tails around seagrass and corals to avoid being carried away on currents. They use the habitat to spawn and hide from predators such as crabs, while also feeding on riches of plankton and small crustaceans living in the reef.
Where corals aren't available, scientists found seahorses taking up residence in fishing nets and old crab traps abandoned at the bottom of the ocean.
This inspired the Sydney team to increase available habitat in the famous Australian harbor by building cages of net and steel. Over time, algae, sponges and corals colonize the structures, creating a safe, welcoming environment for the seahorses, say the researchers. The hotel frame will eventually corrode, leaving behind the coral mounds that have grown around them.
The researchers trialed the first hotels in 2018. Within two months, seahorses had begun to move in and soon a few males fell pregnant. Knowing that the hotels were a hit, the next step was to boost seahorse numbers.
In 2019, the team caught eight pairs of White's seahorses — the creatures are monogamous and, so, mate with one partner for life. The babies were born in September and October of last year.
"We were able to watch them court with each other, and mate with each other, and then we were able to watch the dads deliver," said McCracken, "so, it was always quite exciting."
Mixing With the Locals
Baby seahorse mortality is high in the wild because they are easily caught, so those bred in the protected environment of the aquarium weren't ready to be released into the wild until early May.
The team released 90 new arrivals into Sydney Harbor, placing some directly into the purpose-built hotels, and others onto a net that wild seahorses had already settled on.
Before setting them free, the researchers marked each young seahorse with a fluorescent tag with unique IDs inserted just beneath the skin to track how they get on in the different environments.
"The most exciting part was being able to put these animals into the wild and then go back a month later and still see them surviving and growing," said McCracken.
The seahorses will be old enough to mate and reproduce around October or November 2020. And researchers hope that by then, they will be able to breed with the wild population.
Building a Global Seahorse Hotel Chain
With seahorses everywhere facing the loss of their coral reef homes, similar projects have sprung up in places like Greece and South Africa, home to the world's most endangered seahorse, the Knysna seahorse.
"The endangered South African seahorse is benefiting from something quite similar, even though it wasn't intentional," said Peter Teske, professor at the Department of Zoology, University of Johannesburg.
In the South African case, seahorses have bedded down in "Reno mattresses" — wire cages filled with rocks — that were used to build a new marina. Researchers from NGO Knysna Basin Project found the structures acted as a refuge for the animals.
While Teske describes the seahorse hotels as "a positive news story" and a great way to create public awareness of conservation, he added that establishing artificial habitats in some areas will only prevent the extinction of local populations.
"For a complete recovery, it is necessary to give the natural habitat a chance to regenerate," said the seahorse expert.
In Australia, the researchers hope the project could provide an opportunity to raise awareness not only of the plight of the Sydney seahorses but the other animals with which it shares its ocean habitat.
The waters around Sydney and the east coast are rich in biodiversity and include several threatened species like the weedy seadragon — a relative of the seahorse — and the grey nurse shark. Like the seahorse, they're also under pressure from pollution, ocean traffic and habitat loss through storms and coastal construction.
"It's a good thing to get people's support and interest. The seahorses are a useful vehicle to get people concerned if the harbor is in trouble," said David Booth, professor of marine ecology at the University of Technology Sydney who is also working on the project.
The hotels have become an attraction for divers hoping to catch a glimpse of these small but near mythical creatures.
"Everyone loves seahorses," added Booth, "they are so popular."
Reposted with permission from Deutsche Welle.
- 7 Amazing New Fish Species Discovered in 2017 - EcoWatch ›
- Millions of Seahorses Wind Up Dead on the Black Market for This ... ›
- Seagrass Could Play a Major Role in Slowing Climate Change ›
EcoWatch Daily Newsletter
- Singapore Will Plant One Million Trees by 2030 - EcoWatch ›
- Australia to Build the World's Largest Solar Farm to Power Singapore ›
- Giant Water Battery Cuts University's Energy Costs by $100 Million ... ›
By Tara Lohan
In 1999 a cheering crowd watched as a backhoe breached a hydroelectric dam on Maine's Kennebec River. The effort to help restore native fish populations and the river's health was hailed as a success and ignited a nationwide movement that spurred 1,200 dam removals in two decades.
Transmission lines from the Churchill Falls generating station in Labrador. Douglas Spott / CC BY-NC 2.0
Atlantic sturgeon were brought to the brink of extension in the 20th century and are now are listed as an endangered species. NOAA
Near Happy Valley-Goose Bay on the Churchill (Grand) River downstream from Muskrat Falls. Douglas Sprott / CC BY-NC 2.0
Construction of the Site C dam in British Columbia in 2017. Jason Woodhead / CC BY 2.0
The Block Island Wind Farm off the coast of Rhode Island is the first U.S. offshore wind farm. Dennis Schroeder / NREL / CC BY-NC-ND 2.0
We pet owners know how much you love your pooch. It's your best friend. It gives you pure happiness and comfort when you're together. But there are times that dogs can be very challenging, especially if they are suffering from a certain ailment. As a dog owner, all you want to do is ease whatever pain or discomfort your best friend is feeling.
The excess carbon dioxide emitted by human activity since the start of the industrial revolution has already raised the Earth's temperature by more than one degree Celsius, increased the risk of extreme hurricanes and wildfires and killed off more than half of the corals in the Great Barrier Reef. But geologic history shows that the impacts of greenhouse gases could be much worse.
- Earth Is Hurtling Towards a Catastrophe Worse Than the Dinosaur ... ›
- Are We Doomed If We Don't Curb Carbon Emissions by 2030 ... ›
- Humans Release 40 to 100x More CO2 Than Volcanoes, Major ... ›
By Teri Schultz
Europe is in a panic over the second wave of COVID-19, with infection rates sky-rocketing and GDP plummeting. Belgium has just announced it will no longer test asymptomatic people, even if they've been in contact with someone who has the disease, because the backlog in processing is overwhelming. Other European countries are also struggling to keep up testing and tracing.
Meanwhile in a small cabin in Helsinki airport, for his preferred payment of a morsel of cat food, rescue dog Kossi needs just a few seconds to tell whether someone has coronavirus.