Fireworms are thriving in the warming Mediterranean region due to climate change, leading to reduced fish catch and burning tourists who go swimming.
The fish in Alfonso Barone’s nets pulled up off the coast of Sicily are all gnawed by the fireworm (Hermodice carunculata), a voracious predator thriving in the warming Mediterranean Sea, according to AFP. This centipede-like creature measures 15 to 30 cm in length and voraciously consumes everything from coral to dead or dying fish caught in fishing nets. Rising sea temperatures due to climate change are driving their numbers to surge.
Fireworms can regenerate when cut in half. (Photo: AFP).
Barone yanked a squirming red worm from a headless mackerel on his boat. Its toxic, stiff white bristles fell off with just a light touch. The 34-year-old fisherman reported that he has been stung several times, even once in the eye. Fish are attacked the moment they get caught in the nets. “Fireworms eat the head, the entire body, and the fish’s intestines,” said Barone, who specializes in fishing near the village of Marzamemi in southeastern Sicily.
Fireworms are native to the Mediterranean but were previously few in number and only appeared in Sicily during the summer. With global warming, the sea temperatures are rising, creating an ideal environment for them to thrive year-round, year after year, according to Barone. Fish that are gnawed can’t be sold, so fishermen are reducing their time spent casting nets to prevent the worms from consuming their catch. As a result, the catch yield is lower, with a significant portion still being nibbled by the brown, green, or red worms. The proportion of fish eaten by them has increased from about 30% to 70%.
Fireworms are also migrating northward. Francesco Tiralongo, a zoologist leading a fireworm research project at the University of Catania, noted numerous specimens in Calabria, southern Italy. He explained that fireworms are opportunistic organisms that act like both predators and scavengers. The number of worms in shallow waters is massive. On the beaches of Marzamemi, many locals wear masks or boots before diving. When entering the water, 51-year-old tourist Salvatore Lazzaro, who was stung by a fireworm the day before, still dared to swim again under the glaring sun.
Fireworms not only cause concerns for fishermen but also scare beachgoers. Global warming is leading to several changes in the Mediterranean, and the situation may worsen in the coming years, according to Federico Betti, an expert on invasive species at the University of Genoa. The average temperature of the Mediterranean has increased by about 1.2 degrees Celsius over the past 40 years.
Warming sea waters mean less seasonal fluctuations, destroying deep-sea populations and eliminating habitats, leading to a more homogeneous environment that cannot support a diverse and rich ecosystem. The heat also causes mass die-offs in some species. However, some invasive species, such as the blue crab, have adapted well to the Mediterranean waters.
The blue crab has no natural predators, although Italians are trying to turn it into a delicacy. But fireworms are not a viable food source. While more research is needed to find solutions, Tiralongo made a concerning discovery.
“You cannot kill a fireworm by cutting it in half, as it has remarkable regenerative abilities. If cut in half, not only does the head grow back a tail, but the tail also regenerates a head in just 22 days,” he said.
