Life in the ocean's twilight zone ‘could disappear’ amid warming seas. Less food is falling to dimly lit waters, home to specially adapted marine life – but emissions cuts would stem decline. Life in the ocean’s twilight zone is expected to face dramatic declines and even extinction as seas warm and less food reaches the dimly lit waters, a study has found. The twilight zone lies between 200 metres and 1,000 metres below the surface and is home to a variety of organisms and animals, including specially adapted fish such as lantern sharks and kite fin sharks, which have huge eyes and glowing, bio-luminescent skin. Twilight zone animals feed on billions of tonnes of organic matter, such as dead phytoplankton and fish poo, which drifts down from the ocean’s surface. The drifting particles are known as marine snow. Warmer waters were in effect reducing the quantity of food that sunk down to the zone, meaning up to 40% of life in the twilight waters could be gone by the end of the century, according to the study, which was published in Nature. Recovery could take thousands of years. “The rich variety of twilight zone life evolved in the last few million years, when ocean waters had cooled enough to act rather like a fridge, preserving the food for longer and improving conditions allowing life to thrive,” said Katherine Crichton, the study’s lead author and a postdoctoral research fellow at the University of Exeter.

“According to the studies we have done, 15m years ago there wasn’t all this life [in the twilight zone] and now, because of human activity, we may lose it all. It’s a huge loss of richness,” Crichton told the Guardian. “Unless we rapidly reduce greenhouse gas emissions, this could lead to the disappearance or extinction of much twilight zone life within 150 years, with effects spanning millennia thereafter.” Warmer oceans also reduced carbon storage, said Cardiff University’s Paul Pearson, the principal investigator on the study. This is because the “carbon that is sinking down as part of the marine snow” is eaten mostly by microbes nearer the surface, instead of falling further. Less sinking means a faster carbon release. Crichton said the good part about the study was that “we don’t seem to have reached an irreversible point. We can’t avoid some loss, but we can avoid the worst if we control emissions.” Although poorly understood, the twilight zone “contains possibly the world’s largest and least exploited fish stock, and recycles [about] 80% of the organic material that sinks”, according to a UN programme that studies the region. “We still know relatively little about the ocean twilight zone, but using evidence from the past we can understand what may happen in the future.” Her team’s findings suggested “significant changes may already be under way”.The study offered three possible futures for the twilight zone....read more......  https://www.theguardian.com/environment/2023/apr/27/life-in-oceans-twilight-zone-could-disappear-amid-warming-seas

 Buried in marshes': sea-level rise could destroy historic sites on US east coast. New research shows by the end of the century an increase in sea level will threaten the White House, early colonial settlements and other historic places. Large tracts of America’s east coast heritage are at risk from being wiped out by sea level rise, with the rising oceans set to threaten more than 13,000 archaeological and historic sites, according to new research. Even a modest increase in sea level will imperil much of the south-eastern US’s heritage by the end of the century, researchers found, with 13,000 sites threatened by a 1m increase. Thousands more areas will be threatened as the seas continue to climb in the years beyond this, forcing the potential relocation of the White House and Lincoln Memorial in Washington DC and inundation of historic touchstones such as the Kennedy Space Center and St Augustine, Florida, which lays claim to being the oldest city in the US. “Some sites will be destroyed, some buried in marshes. We may be able to relocate some. In some places it will be devastating. We need to properly understand the magnitude of all this.” Threatened areas, including locations on the national register of historic places, include Native American sites that date back more than 10,000 years, as well as early colonial settlements such as Jamestown, Virginia and Charleston, South Carolina. Researchers pinpointed known sites using topographical data and analyzed how they would fare in various sea level rise scenarios. Florida, which has a southern portion particularly vulnerable to sea level rise, has the most sites in danger from a 1m rising of the oceans, followed by Louisiana and Virginia. A 1m sea level rise by 2100 could prove optimistic, with several studies showing the increase could be much greater. Scientists have warned that the break up of the Antarctic ice sheet could significantly fuel sea level rise, pushing the global increase to around 6ft by 2100.The latest US government estimate predicts a worldwide increase of 1ft to 4ft by 2100, although an 8ft rise “cannot be ruled out”. The eastern seaboard of the US is at particular risk, with water piling up along the coast in greater volumes than the global average. The problem is compounded by areas of the coast, such as in New Jersey and Virginia, gradually subsiding due to long-term geological hangover from a vast ice sheet that once covered much of North America. Sea level rise is expected displace millions of people from the US coasts over the next coming decades.          https://www.theguardian.com/environment/2017/nov/29/buried-in-marshes-sea-level-rise-could-destroy-historic-sites-on-us-east-coast    

 Countries Reach Agreement to Conserve and Sustainably Use High Seas. “The ship has reached the shore,” said Rena Lee, President of the Intergovernmental Conference (IGC) tasked with negotiating a new treaty on the conservation and sustainable use of marine biological diversity of areas beyond national jurisdiction (BBNJ). After a decade and a half of work, including four years of formal talks, governments agreed to conserve and sustainably use the high seas. The resumed fifth session of the Intergovernmental Conference (IGC-5.2) convened from 20 February to 4 March 2023 at UN Headquarters in New York, US, to pick up where delegates left off in August 2022, when IGC-5.1 wasunable to get the negotiations over the finish line. The Earth Negotiations Bulletin (ENB) summary report of the meeting notes that the Ocean “constitutes over 90% of the habitable space on the planet and contains some 250,000 known species.” Nearly two-thirds of the Ocean involves “Balancing conservation and sustainable use is a demanding undertaking,” writes ENB in its analysis. “But when benefit-sharing requirements are added to the equation, achieving the right balance is even more difficult.” The new agreement, ENB underscores, “is a critical piece of the conservation puzzle.” The 1982 UN Convention on the Law of the Sea (UNCLOS) provides the overarching framework. Specific activities are regulated by subsequent agreements, including the 1995 UNCLOS Implementing Agreement relating to the Conservation and Management of Straddling Fish Stocks and Highly Migratory Fish Stocks, and the 1994 Agreement Relating to the Implementation of UNCLOS Part XI on deep-sea mining. According to ENB, the new treaty will fill in remaining gaps, including.....read more                 http://sdg.iisd.org/news/countries-reach-agreement-to-conserve-and-sustainably-use-high-seas/

 Walmart, Target, Home Depot lead pack of retailers emitting millions of pounds of CO2 through shipping. Eighteen U.S. companies’ cargo ships are causing an "onslaught of pollution,” report finds. 2021 was a big year for the global shipping industry, as COVID-19 drove hordes of shoppers to the internet to buy new clothes, gadgets, furniture, and other goods. Booming e-commerce contributed to widely reported supply chain disruptions — but it also led to less-reported consequences for the climate and public health. A new report from the nonprofits Pacific Environment and Stand.earth finds that the ships that carried imports for 18 of the U.S.’s largest retail, fashion, tech, and furniture companies emitted about 3.5 million metric tons of greenhouse gases in 2021, about as much as the annual climate pollution from 750,000 passenger cars. The ships transporting these companies’ clothes, computers, knickknacks, and other goods also released thousands of metric tons of cancer- and asthma-inducing nitrous oxide and particulate matter into port communities. The report brings “awareness and accountability to the companies that were behind that onslaught of pollution in 2021,” said Madeline Rose, Pacific Environment’s climate campaign director. She called on retail companies to demand cleaner shipping fuels and practices from the freight companies they pay to transport their goods, with an eye toward net-zero emissions by 2030. Pacific Environment’s report shines a spotlight on 18 major maritime importers in four retail categories, chosen based on their shipping emissions and their recognizability. Walmart, Target, and Home Depot led the pack in maritime climate and air pollution, together causing more than 1.7 million metric tons of carbon dioxide and 33 metric tons of methane to be released into the atmosphere in 2021. The report attributes this pollution to the brands’ partnerships with shipping companies whose vessels rely on carbon-intensive heavy fuel oil. These vessels aren’t an anomaly; most of the planet’s maritime freight fleet is highly polluting, and the industry writ large accounts for about 3 percent of global greenhouse gas emissions. Besides contributing to climate change, the ships that U.S. companies rely on also release hazardous air pollution in port communities, whose residents tend to be lower-income people of color.  For example, ships carrying goods for Walmart emitted thousands of metric tons of nitrogen oxide, sulfur oxide, and particulate matter during voyages to the Port of Houston in 2021, potentially elevating the risk of cancer and respiratory problems for port residents.            https://grist.org/accountability/walmart-target-home-depot-lead-pack-of-retailers-emitting-millions-of-pounds-of-co2-through-shipping/