Starting in 2018, gray whales began regularly stopping in California’s San Francisco Bay, where they are vulnerable to ship strikes in one of the busiest ports in the United States. In response, researchers have deployed a monitoring network of thermal cameras and AI software to alert ships when whales are present in the bay to help them avoid whale collisions.  Gray whales (Eschrichtius robustus) have one of the longest migrations of any mammal species, roughly 19,000 kilometers (12,000 miles) from their feeding grounds in Alaska to their breeding grounds in Mexico, and back again. Climate change is making their feeding grounds in Alaska less productive, leaving the whales hungry as they head south to breed. Scientists believe that’s why gray whales have started stopping in San Francisco Bay to eat along their migration route. But the new pit stop brings whales into busy shipping zones, where more than 20 were killed by ship collisions in 2025, according to a news release. Whale biologists at the Benioff Ocean Science Lab, WhaleSpotter, and the Marine Mammal Center have developed thermal cameras that can detect the heat signature of whale spouts and bodies when the whales surface.  “Next a trained human confirms the detection and will help classify the species when possible,” Rachel Rhodes, a project scientist with the Benioff Ocean Science Lab told Mongabay in an email. Then the information is, “posted publicly on [the] Whale Safe website, which is accessed by mariners in the Bay Area including Vessel Traffic Service and…This article was originally published on Mongabay

A massive slab of wartime concrete blocked the Pčinja River in Kumanovo, North Macedonia for more than 70 years. A 53-meter-long and 30-meter-wide (174 by 98 feet) structure of reinforced concrete packed with salvaged railway steel impeded the free flow of water and fish for at least 70 kilometers (44 miles) upstream. It was considered a safety hazard by the local Shuplji Kamen community. In late 2025, the barrier was demolished after efforts by the nation’s Eko-svest environmental organization. It was the first large-scale removal of its type in North Macedonia. It was also one of 603 obsolete river barriers, including dams, weirs and culverts, removed from European rivers in 2025, according to the 2025 Dam Removal Europe report. Researchers estimated removing those objects reconnected more than 3,740 km (2,324 miles) of rivers across the continent, a new single year record for dam removal in Europe. “Barrier removal [is] one of the biggest ecological ‘easy wins’ available today,” Chris Baker, director of Wetlands International Europe (WIE) wrote in a statement. “These obsolete barriers no longer provide any benefits, yet they continue to degrade rivers.” According to WIE, there are roughly 1.2 million barriers in place today that fragment Europe’s rivers, of them more than 150,000 are “considered obsolete.” Since 2020, nearly 2,300 dams have been removed across Europe, mostly in Sweden, Finland and Spain. Iceland, along with North Macedonia, carried out its first removal in 2025. Iceland removed an old hydroelectric dam that was no longer in use. The barrier…This article was originally published on Mongabay