How changing ocean colors could impact California
Earth's oceans have been getting greener at the poles and becoming bluer closer to the equator, according to a study published Thursday in Science. The shift reflects changes in marine ecosystems, which experts say could affect fish populations and create problems for fisheries, including in California.
'It has lots of potential implications for the way we use the ocean,' said Raphael Kudela, a professor of ocean sciences at UC Santa Cruz, who wasn't part of the new study.
The scientists analyzed satellite data from 2003 to 2022 to track ocean concentrations of chlorophyll, a green pigment that phytoplankton use to absorb sunlight and produce sugars. While phytoplankton are often associated with harmful algal blooms, they are also the base of the marine food web, serving as food for fish and other sea creatures.
Ocean regions with the highest concentrations of chlorophyll, or the greenest areas, were at higher latitudes, toward the poles. Mid-latitudes had relatively low levels of chlorophyll, or were more blue.
The authors tracked global shifts in chlorophyll concentrations, a proxy for phytoplankton populations, over recent decades. The authors associated the poleward 'greening' with increasing sea-surface temperatures.
'This uneven distribution of chlorophyll (has been) intensifying over the past 20 years,' said lead author Haipeng Zhao, a postdoctoral researcher at the Georgia Institute of Technology. Zhao performed the research while at Duke University.
The scientists quantified the trend using the Gini index, a measure typically used for studying wealth disparities. Kudela, of UC Santa Cruz, described the approach as 'a very elegant way' to address the question of whether ocean waters have been getting greener toward the poles.
The new study analyzed open ocean waters; researchers didn't directly address coastal regions, like the Pacific Ocean waters offshore of California. Sediment in shallow coastal waters complicates satellite data: 'We don't think there's an effective algorithm that can accurately gather the phytoplankton concentrations in those coastal regions,' Zhao said. Coastal waters and the open ocean also experience distinct physical processes, Zhao explained.
Kudela expects that the poleward shift in chlorophyll and phytoplankton described by the authors extends to the California coast, though the data could be noisier. Much of California lines up with latitudes associated with ocean waters that have gotten bluer over recent decades. Latitudes north of roughly Humboldt Bay have gotten greener.
Scientists have already observed changes in marine environments: 'We're seeing organisms in California and Oregon and Washington moving northward because they're basically trying to follow their preferred temperature,' said Kudela, who authored a perspective accompanying the new study.
Kudela noted in the perspective that the new results contrast with those of a 2023 study, which reported that oceans have become greener at low latitudes in recent decades and that the trend wasn't associated with sea-surface temperatures. That analysis, however, used a different type of satellite observation.
El Niño conditions, associated with warmer-than-average sea surface temperatures, have provided short glimpses into what California waters could be like if global oceans warm, Kudela said.
'We oftentimes see the peak anchovy abundance shifts from Central California (and) Monterey up into Northern California,' Kudela said.
Yellowfin tuna and dorado, normally found off Mexico, are more common off Southern California during El Niño years.
The authors write that additional decades of satellite data are needed to determine whether poleward greening is a product of natural variability or driven by climate change.
Try Our AI Features
Explore what Daily8 AI can do for you:
Comments
No comments yet...
Related Articles
Yahoo
3 hours ago
- Yahoo
Plants emit insect-repelling chemical that could secretly be poisoning our air
In the 2008 film 'The Happening', plants turned against humans in an eerie twist of nature, releasing invisible neurotoxins that drove people to their deaths. It was pure sci-fi horror, but the idea that plants can chemically shape the world around them isn't fiction. In fact, the air we breathe carries traces of a quieter kind of warfare — not against people, but pests. Scientists at Michigan State University have cracked a 40-year mystery around isoprene, a natural chemical that some plants emit to repel hungry insects. But there's a twist: while it defends the plant, it could be polluting the air. Isoprene is a colorless, volatile hydrocarbon, a simple organic compound made up of five carbon atoms and eight hydrogen atoms (C₅H₈). It's naturally released by certain plants, especially in hot weather, and is one of the most abundant hydrocarbons emitted into the atmosphere, second only to methane. Unlike the fragrant terpenes you'd smell in pine forests or poplar groves, isoprene is odorless yet highly reactive. Once released, it interacts with sunlight and nitrogen oxides from vehicle exhaust and industrial emissions, contributing to the formation of ozone, aerosols, and other pollutants that degrade air quality. 'Everyone understands what it smells like when you walk through a pine forest,' Sharkey said. 'In an oak grove, which has more hydrocarbons because it makes so much isoprene, you just don't notice it.' Until now, scientists weren't entirely sure why some plants go to the trouble of producing isoprene at all, especially since it doesn't seem to help them grow. But the new research suggests the answer lies in defense, not just against heat stress, but against hungry insects. In controlled greenhouse experiments, MSU researchers grew two types of tobacco plants — one genetically modified to emit isoprene, the other left unchanged. When whiteflies invaded, they swarmed the non-emitting plants while avoiding the isoprene producers altogether. Further tests using hornworms confirmed the pattern. Worms that fed on isoprene-rich leaves grew smaller and weaker than those that didn't. But it wasn't the isoprene itself that harmed them. Instead, the chemical triggered a spike in jasmonic acid, a defense hormone that disrupts an insect's ability to digest protein. 'The defense was not the isoprene itself, but the consequence of what isoprene did to the plant,' Sharkey said. Another surprise came from soybeans. Long believed to have lost the ability to make isoprene through evolution, soybeans were found to release it in small bursts when their leaves were damaged. The discovery suggests they still carry the gene to produce isoprene and switch it only under stress. Researchers say this discovery could change the way we protect crops. But that upside comes with a downside. Isoprene is a hydrocarbon that can worsen air pollution, especially in areas where air quality is already poor. If more crops are genetically modified to emit isoprene, it could further harm the atmosphere. The findings also raise concerns about how soybeans might be contributing to air pollution. 'That's one of the questions that's most important to come out of this research,' Sharkey said. 'Should we add isoprene to crop plants so that they're protected against insects and put up with their effect on the ozone? Or should we genetically engineer plants to turn off the isoprene synthase as much as we can to improve the atmosphere?' The findings come from two new studies published in Science Advances and the Proceedings of the National Academy of Science.
Yahoo
7 hours ago
- Yahoo
New Zealand PM Luxon meets China's Xi Jinping
(Reuters) -New Zealand Prime Minister Christopher Luxon said on Friday he and China's President Xi Jinping discussed the role of business, education and science to help boost relations between the two countries. "I raised the importance to New Zealand of the international rules-based system, as well as the key role that China can play in helping to resolve global challenges," Luxon said in a statement after meeting Xi Jinping in Beijing.
Yahoo
8 hours ago
- Yahoo
"We Now Need to Create Opportunities Across Sectors" - UK Minister Patrick Vallance Urges Deeper UK-India Science Partnerships
Science Museum hosts IGF Future Frontiers Forum spotlighting science, tech & innovation collaboration between India and UK NEW DELHI and LONDON, June 20, 2025 /PRNewswire/ -- At the Future Frontiers Forum hosted by IGF London, Patrick J. Vallance, UK Minister of State for Science, Research and Innovation, called for intensified UK–India collaboration in science and technology, urging both nations to align their innovation priorities and unlock sector-wide opportunities. "The industrial strategy coming out in just a couple of weeks which will list the eight sectors we are working on. That's got to be a good foundation for where there can be partnerships," Vallance stated. "India has its focus areas, we have ours, now we need to create opportunities across those sectors." Speaking at the Science Museum, Vallance emphasised the importance of people-to-people scientific ties: "I believe government-to-government relationships in science do not drive everything; we must also create scientist-to-scientist relationships. Academic links and the exchange of people often drive collaborations. Start-ups in particular are becoming central to the innovation ecosystem, and we need more of them in the UK–India mix." The forum, part of IGF London 2025, brought together government leaders, global CEOs, investors, and academics to explore frontier technologies across AI, climate tech, sustainable energy, health innovation, and quantum computing. Opening the event, Sir Ian Blatchford, Director of the Science Museum, celebrated the UK–India Science and Innovation Partnership Roadmap and its focus on critical and emerging technologies. "The Technology Security Initiative is a landmark step," he said. "Imperial College's science hub in Bengaluru will drive collaboration in AI, healthtech, cleantech, and advanced materials, backed by $170 million in joint UK–India funding." India's Commerce & Industry Minister Piyush Goyal highlighted the FTA's role in strengthening innovation ecosystems: "It's not just about trade or investment. The FTA demonstrates that India and the UK are friends and allies. Innovation in India happens at a fraction of global costs. What takes 10x the cost in the US or Europe can be done efficiently in India, with mutual benefit." Sir Oliver Dowden, former UK Deputy Prime Minister, reinforced the values-based alignment between the two democracies: "We must deepen ties with like-minded nations. UK and India share heritage, rule of law, and a commitment to science. Whether it's 6G or quantum, setting international standards together creates a win-win." Health innovation was another key focus, with leaders like Lord Ara Darzi, Alisha Moopen (Aster DM Healthcare), and Monica Huang (Zydus Lifesciences) exploring how India's affordable, tech-driven models could support the UK's struggling NHS. "The NHS isn't in critical condition, but it needs urgent reform," said Lord Darzi. "India's transformative health solutions and COVID-era support show the intellectual and production power we must now collaborate with." A major highlight was the return of Pitchers and Punters, a curated showcase of Indian start-ups pitching to a jury of international investors. Among the standout companies were Zypp Electric, Lina Energy, Steamology Motion Ltd and Electric Miles—with Zypp Electric winning the Clean Tech Award, presented by Octopus Energy. The punters included Neha Manaktala (JP Morgan Climate Tech), Richard Heald (EET), James Edison (Octopus Energy) and Bhavit Sheth (Dream11 & Dream Sports) who praised the depth of Indian innovation in sustainability and AI. Other sessions featured voices like Daniel D'Souza (DreamSetGo), Reena Dayal (Quantum Ecosystems Council of India), and experts from EET, exploring opportunities across deep tech, telecom, and digital health. As global tech landscapes grow more complex and fragmented, IGF London's Future Frontiers Forum showcased a clear vision: the UK and India must build trusted, innovation-led alliances that translate ambition into scalable action. The forum forms part of IGF London 2025. With over 100+ speakers, 1000 participants, and events across iconic venues in London, IGF London 2025 encompasses a spectrum of topics - from technology and trade to culture and commerce. This year's edition marks a powerful milestone - a decade since Prime Minister Narendra Modi's landmark 2015 visit to the UK, and the two nations have finalised the long-awaited Free Trade Agreement. IGF London is the first major international platform to celebrate and analyse this historic achievement, unlock new opportunities that emerge from its conclusion, and shape the next phase of UK-India collaboration. About India Global ForumIndia Global Forum tells the story of contemporary India. The pace of change and growth India has set itself is an opportunity for the world. IGF is the gateway for businesses and nations to help seize that opportunity. To know more, click here. Social Media Handles & Hashtag to Follow Twitter: @IGFUpdates & @manojladwaLinkedIn: India Global Forum#IGFLondon Photo: - View original content to download multimedia:
