A leading cause of a rising pH value in the world’s oceans is human CO2 emission. As more CO2 is released into the atmosphere and absorbed by the oceans, the water becomes more acidic. This poses problems for many organisms – including sharks, a new study showed. Scientists incubated shark teeth in water with pH levels that reflect the current ocean pH, and in water with a pH value that oceans are predicted to reach by 2300. In the more acidic water of the simulated scenario, shark teeth, including roots and crowns, were significantly more damaged. This shows how global changes reach all the way to the microstructure of sharks’ teeth, the researchers said.

Research published in Proceedings of the National Academy of Sciences confirms that fossilized marine invertebrates serve as a powerful tool for understanding long-term ecological change and informing modern conservation efforts.

A deep sea worm that inhabits hydrothermal vents survives the high levels of toxic arsenic and sulfide in its environment by combining them in its cells to form a less hazardous mineral. Chaolun Li of the Institute of Oceanology, CAS, China, and colleagues report these findings in a new study published August 26^th in the open-access journal PLOS Biology.

New Arizona State University research reveals the extent to which sewage pollution threatens the fragile coral reef ecosystems of West Hawaiʻi Island. The study identifies exactly where sewage-contaminated water is entering the ocean, further damaging coral reefs already impacted by climate change, and endangering human health. The research team used advanced airborne mapping techniques, along with comprehensive field sampling and sophisticated statistical models, to pinpoint locations where high levels of fecal bacteria associated with populated coastal areas are driving worsening contamination. The study provides the critical data needed by government officials and local communities to mitigate this threat and protect the health and biodiversity of coastal ecosystems.

Some 390 million years ago in the ancient ocean, marine animals began colonizing depths previously uninhabited. New research indicates this underwater migration occurred in response to a permanent increase in deep-ocean oxygen, driven by the aboveground spread of woody plants — precursors to Earth’s first forests. 

A study in National Science Review reports systematic observations of diazotroph abundance, community structure, and N₂ fixation rates in the western North Pacific. Using generalized additive models, the team characterized ecological niches of key cyanobacterial diazotrophs and quantified UCYN-B’s contribution to global N₂ fixation. The findings highlight UCYN-B’s pivotal role in marine N₂ fixation and provide new insights into ocean nitrogen cycle and productivity under climate change.

A new study published by researchers at the University of Hawai‘i at Mānoa sheds light on the critical role of iron in Earth’s climate history, revealing how its sources in the South Pacific Ocean have shifted over the past 93 million years. This groundbreaking research, based on the analysis of deep-sea sediment cores, provides crucial insights into the interplay between iron, marine life, and atmospheric carbon dioxide levels.

Tulane researchers found that mid-1990s climate projections of sea-level rise were remarkably accurate when compared with 30 years of satellite data. The 1996 IPCC report predicted about 8 cm of rise, close to the 9 cm observed, though it underestimated ice-sheet contributions. The study highlights both the credibility of climate models and the importance of continued monitoring. Researchers stress the need for region-specific projections, especially for vulnerable coastal areas like south Louisiana, where sea-level rise varies widely.

A research team led by a Ph.D. student at the University of Miami Rosenstiel School of Marine, Atmospheric, and Earth Science has developed a new artificial intelligence (AI) tool that can automatically identify and track tropical easterly waves (TEWs)—clusters of clouds and wind that often develop into hurricanes—and separate them from two major tropical wind patterns: the Intertropical Convergence Zone (ITCZ) and the monsoon trough (MT).