The golden squid swims back to Mexico.
About a quarter of a century since the shiny little fish disappeared from its only natural habitat, the golden skipjack (Skiffia francesae) has been released back into the wild. The moment coincided with the traditional Día de Muertos celebrations.
“The Day of the Dead is a traditional Mexican celebration, when people’s deceased ancestors are believed to return to the land of the living one night, to talk and spend time with their families,” said Omar Domínguez-Domínguez, professor and teacher researcher at the University of Michoacan in Mexico, who led the reintroduction.
“Releasing the golden squid at this time is a metaphor for how the species has come back from the dead to return home, not for one night, but forever.”
Researchers aren’t sure why the golden skiffia disappeared in the wild because the fish wasn’t studied before it went extinct. They last saw each other in the 1990s. They suspect that pollution and the introduction of other species likely led to their demise, Dominguez-Dominguez tells Treehugger.
They play an important role in the ecosystem because they regulate algae and eat the larvae of disease-carrying mosquitoes.
Because the fish are so small, they are of little value to some fisheries that harvest goodeids, this family of fish. Many of them are known as splitfins. Species losses like these can affect some threatened freshwater fish around the world, says Harmony Patricio, SHOAL conservation program manager and director of Re:wild’s freshwater fish conservation program.
SHOAL is a global association working for the conservation of freshwater fish. Re:wild’s mission is to protect and restore the biodiversity of life on Earth.
“Knowledge gained through research and action to conserve goodeids is relevant to effectively conserving a wide range of fish,” Patricio tells Treehugger.
“They also act as indicators of the health of a freshwater system: when fish populations are healthy, so is the ecosystem. When populations are declining, it’s a sign of a failed system. Fish and freshwater ecosystems are a critical part of the livelihoods and well-being of humans worldwide.”
Scientists released about 1,200 golden skipjack into their native habitat on the upper Teuchitlán River in Jalisco, Mexico. The fish came from a conservation breeding program.
“The fish were marked and we will do samples every two months to follow the population,” says Domínguez-Domínguez. “We hope that in the coming months we will start to find untagged fish, which will be a sign that the species is surviving and reproducing in the wild.”
In order to prepare for release, the fish were first placed in ponds to learn to adapt to semi-captive situations. They were wormed and marked for identification and then placed in floating cages in the river for at least a month so they could acclimate to natural conditions.
Plans for its release began in 2014, when scientists from the University of Michoacan in Mexico and fishermen from the Goodeid Working Group began to eliminate the threats that caused the species to become extinct in the wild. They helped restore golden squid habitat and began removing non-native species from the ecosystem.
“The team that launched the Golden Squid has been preparing for this for years and has learned a lot along the way,” says Patricio.
“They conduct regular population monitoring surveys and hope that reproduction rates will reach the levels necessary for the population to become self-sustaining. We hope that this reintroduction can serve as a model and conservation success story for similar efforts around the world”.