{"id":245544,"date":"2025-10-23T07:45:11","date_gmt":"2025-10-23T07:45:11","guid":{"rendered":"https:\/\/www.newsbeep.com\/us\/245544\/"},"modified":"2025-10-23T07:45:11","modified_gmt":"2025-10-23T07:45:11","slug":"unwanted-travelers-on-international-ships-dw-10-22-2025","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/us\/245544\/","title":{"rendered":"Unwanted travelers on international ships \u2013 DW \u2013 10\/22\/2025"},"content":{"rendered":"

At the fish stall in the village of Aspra, near the Sicilian capital of Palermo, the day’s catch is garnished in green. But far from being an ingredient to be cooked up as a side dish, it is the worst enemy of local fishermen. Known as Rugulopteryx okamurae, this invasive seaweed<\/a> has become the bane of their lives. For the past two years they have spent days at a time untangling it from their nets, watching their income suffer as a result.<\/p>\n

The problem is well known among their fellow fishers in Spanish waters. “We’ve had the algae here for 10\u00a0years,”\u00a0says Gregorio Linde, skipper of a small-scale fishing boat in Tarifa, on the Gibraltar Strait. “The seabed is a carpet of it, and the nets don’t catch anything.”<\/p>\n

His family has lived from the fruits of the sea for generations, but now his days often consist of hauling seaweed \u2014 just to dump it back. And he is not alone. Losses to such small-scale fisheries<\/a> in Spain<\/a> exceed \u20ac3 million ($3.48 million) annually.<\/p>\n

\"ATarifa fishermen call for stricter measures against invasive Rugulopteryx okamuraeImage: Irene Ba\u00f1os\/DW<\/p>\n

And it is also harming\u00a0coastal tourism in countries like Spain and Italy,<\/a> where vacationers wrinkle their noses as they tiptoe through foul-smelling mats of algae on once white-sand beaches. Despite the effort and cost of carting it off to landfill, new tides refill the beaches.<\/p>\n

The greatest damage, however, is out of sight. Underwater, the seaweed is smothering vital seagrass meadows, harming sea urchins and occupying fish shelters.\u00a0<\/p>\n

“Socioeconomic impacts can be offset with money, but this unprecedented ecological impact cannot,”\u00a0warns Maria Altamirano, a researcher at the University of Malaga, who first identified the algae<\/a> in Spain. The\u00a0“invasion “is like a wildfire in a national park: Everything is wiped out, and only one species remains,” she says.<\/p>\n

\"MassiveLocal governments in southern Spain regularly bring tons of seaweed from beaches to landfill sitesImage: Irene Ba\u00f1os\/DW<\/p>\n

The Mediterranean: A\u00a0hotspot for\u00a0invasions of non-native species<\/p>\n

Though it covers less than 1% of the world’s ocean<\/a> area, the Mediterranean<\/a> hosts nearly a quarter of global maritime traffic. And that, according to the European Environment Agency, is responsible for introducing half of all non-native species into the sea since 1970.<\/p>\n

More than half of all non-native species found in European waters dwell in this semi-enclosed sea, according to Luca Castriota, an invasive species expert at Palermo’s National Institute for Environmental Protection and Research. He says one in 10\u00a0turns invasive, displacing native marine life and reshaping ecosystems<\/a>.<\/p>\n

Rugulopteryx okamurae is\u00a0a major offender. It’s native to the Pacific, where it lives in balance with ecosystems in Japan, China, Taiwan, Korea, and the Philippines.\u00a0The species was first identified as invasive in 2015 in Ceuta, a Spanish enclave on the North African coast, along the Strait of Gibraltar.\u00a0<\/p>\n

\"AIn the small village of Aspra, fishermen fret as the Asian seaweed invades their nets and boatsImage: Irene Ba\u00f1os\/DW<\/p>\n

Encouraged by overfishing and pollution<\/a> \u2014 which weaken ecosystems \u2014 as well as warming waters<\/a> and the absence of natural predators, its aggressive advance didn’t stop there. It has since spread to different parts of the Mediterranean and reached Atlantic archipelagos such as the Canary Islands, the Azores, and Madeira. In 2022, it became the first algae on the EU’s list of concerning alien species.<\/p>\n

How ballast water balances ships and unbalances seas<\/p>\n

Scientists believe the seaweed reached the Mediterranean via ballast water discharged by cargo ships traveling between Asia and Europe. Before leaving harbor, vessels pump water into their internal tanks to stabilize cargo. They then expel it at their destination \u2014 along with any hidden spores, larvae, or eggs.\u00a0<\/p>\n

“Today the world is interconnected. We buy products in China,<\/a> for instance, that are distributed across the planet. But along with the goods we want, we are transporting species from one place to another,”\u00a0explains Maria\u00a0Garcia of the Spanish National Research Council (CSIC). She has been monitoring invasive species in Mediterranean coastal waters for 30 years and says trade is “completely altering”\u00a0its fauna and flora.<\/p>\n

\"AThe Suez Canal and the Strait of Gibraltar are major entry points for invasive species Image: Irene Ba\u00f1os\/DW<\/p>\n

In 2004, the International Maritime Organization (IMO) adopted a convention requiring ships to treat ballast water \u2014 though it only took effect in 2017. And from September last year, ships flying a signatory country’s flag, or discharging ballast in its ports, must install onboard treatment systems preventing anything but tiny particles \u2014 10 microns \u2014 from being discharged.<\/p>\n

Experts call it a step forward, but enforcement remains weak. “Efforts have been ongoing for years, but compliance is difficult because of the costs involved. It often depends on the goodwill of shipowners and crews,”\u00a0Garcia admits.<\/p>\n

Checks rarely rank above other port priorities such as vessel safety. In countries like Spain, authorities are underfunded. Others like Italy have not ratified the IMO convention, which means foreign ships can legally discharge untreated ballast water in the country’s ports.\u00a0<\/p>\n

“We cannot directly intervene with private individuals, because this would conflict with economic activities,”\u00a0Castriota says. “Until the IMO convention is ratified, our hands are tied.”\u00a0<\/p>\n

Cyprus fishermen at war with a toxic invasive species<\/p>\n

To view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 video<\/a><\/p>\n

Citizen science: An ally against the tide<\/p>\n

Once a species is installed, slowing the spread becomes essential. “We know the algae can thrive in a much larger area than it currently occupies. We must prevent it from getting there,”\u00a0Altamirano stresses.<\/p>\n

Stronger ballast water controls and cooperation with fishers and recreational boat owners are key, since nets and hulls often carry the algae further. But civil participation also matters.\u00a0<\/p>\n

It was a citizen science platform that first flagged the Asian algae’s arrival in Murcia, southeastern Spain. And Garcia’s team collaborates with more than 5,000 volunteers in the northern Catalonia region, which is also affected.\u00a0They upload photos of suspected invasive species to the Observadores del Mar platform. “We scientists work in our labs, but there are huge areas of the sea we cannot cover,”\u00a0Garcia says.\u00a0<\/p>\n

\"AGarcia analyzes the ecological impacts of Rugulopteryx okamurae in her laboratory near BarcelonaImage: Juan David Escorcia<\/p>\n

But preventing future invasions will take more than dawn sails and lab experiments.\u00a0<\/p>\n

It requires international coordination, dialogue between science and policymakers and affected sectors, and active citizen participation, Altamirano says.\u00a0<\/p>\n

“Rugulopteryx okamurae is just one of many invasive species,”\u00a0she adds. “We need to have the machinery running smoothly for the next ones that are sure to come.”<\/p>\n

Edited by: Tamsin Walker<\/p>\n

This reporting in this story was supported by\u00a0Journalismfund Europe.<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"At the fish stall in the village of Aspra, near the Sicilian capital of Palermo, the day’s catch…\n","protected":false},"author":2,"featured_media":245545,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[47],"tags":[192,79],"class_list":{"0":"post-245544","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-environment","8":"tag-environment","9":"tag-science"},"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/posts\/245544","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/comments?post=245544"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/posts\/245544\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/media\/245545"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/media?parent=245544"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/categories?post=245544"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/tags?post=245544"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}