BARCELONA, SPAIN—Two major airlines have stopped transporting laboratory animals from mainland Spain to the Canary Islands, an archipelago in the Atlantic Ocean. Their move has put research projects on the islands on hold and has left scientists and politicians scrambling for solutions. The ban is particularly problematic for researchers who need transgenic mice, which are often ordered from specialized labs.

The issue may soon be debated in the Spanish parliament; some members want the federal government in Madrid to force the companies to lift their ban, according to a story in Spanish newspaper El País last week. At the request of the Canarian government, the Spanish civil aviation authority has been negotiating a possible solution with various airlines, local newspaper Diario de Avisos reports.

Air Europa stopped transporting research animals last year, without providing an explanation. Iberia, Spain's national airline, followed suit in March, citing international regulations and safety issues, including the possibility that mice might escape and damage the aircraft. But regulations don't preclude animal shipments, and damage from escaped rodents "has never been reported in the history of aviation,” says a spokesperson for the European Animal Research Association (EARA) in London. EARA suspects the companies have given in to pressure from animal rights activists. Both Air Europa and Iberia continue to fly pets, including some rodent species.

The issue was brought to the media's attention recently by Javier Castro Hernández, a postdoc in rheumatology at the University Hospital of the Canary Islands on Tenerife. Castro had ordered 29 knockout mice from Charles River Laboratories, headquartered in Wilmington, Massachusetts, but the animals have been stranded at an animal facility in Madrid since late September, which costs money and is delaying research, Castro says.

Canarian researchers say some 30 other biomedical research projects at the islands' two universities and at university hospitals will be affected as well. Researchers who need transgenic mice from overseas have put their plans on hold, says Teresa Giraldez, who studies the role of ion channels in neurological diseases at the University of La Laguna on Tenerife. "We cannot take the risk that [the animals] get stuck in Madrid,” says Giraldez, who calls the situation “very worrisome.” Without access to transgenic mice, Castro says he's "competing at a disadvantage" with mainland Spain.

In recent years, animal rights groups have pressured the few airlines that still transported nonhuman primates for research into ending their service. Many companies, including British Airways, which merged with Iberia in 2011, have gone further and have halted shipments of all research animals; so have some ferry companies. Several scientific associations have expressed support for Air France, which is continuing to ship laboratory animals all over the world.

An Iberia spokesperson says Canarian researchers still have other transport options, but researchers have been struggling to find a suitable alternative. The only solution that Castro and his institution could find for his mice is road transport to Lisbon, followed by a flight on Canarian airline Binter. But the long journey would create extra stress for the animals and drive up costs, says Castro, who's hopeful that Spain's civil aviation authority will negotiate a solution. Using a ferry for the more than 1200-kilometer trip across the Atlantic is logistically complex, Giraldez says.

Nuno Franco, who studies laboratory animal welfare and ethics at the University of Porto in Portugal, calls the ban "poorly justified" and "damaging" to science. “Canarian scientists, their institutions, and science itself are being [held] hostage," Franco says. “The issue goes beyond whether we should do animal research or not,” Giraldez says. Regulations across Spain are the same, she says, so "you can't have discrimination of this type” between regions.