Author: Derrick Lester

Off the coast of St. Croix, there is a wall that descends from a reef flat in roughly fifteen meters of water to a location that is unreachable by any diver who has ever gone down it. Coral species, fish groups, and the ecology of what scientists refer to as the mesophotic zone—the twilight band between recreational divers’ halt and the point at which light completely disappears—are all very well described in the higher sections. The wall extends below that. With specialized diving equipment, you may still follow it for a while. After that, it travels to a location that…

In ocean science, sixty years is a long time. Long enough, it turns out, to observe changes in the deep sea that the scientists who first monitored it in the 1960s would not have anticipated. Teams from the Chinese Academy of Sciences, France’s Mercator Ocean International, and the École Normale Supérieure in Paris collaborated on a study published in Nature Climate Change that accomplished something that oceanographers have been working toward for decades: it integrated several ocean variables into a single monitoring framework and systematically asked how much has actually changed since we started paying close attention. The response exceeds…

For many years, meteorologists relied on the following rule: hurricanes do not survive when vertical wind shear is significant. The structured structure that a storm requires to intensify is destroyed by wind shear, which is the variation in wind direction and speed at different altitudes. The engine is knocked out of alignment. Florida International University research professor Hugh Willoughby put it simply: “Shear is death for hurricanes.” He described Hurricane Lee’s formation in September 2023, during an El Niño year that should have created precisely this type of adverse shear environment, as “a nasty surprise.” The mechanism that was supposed…

There is a layer in the Eastern Tropical Pacific where the water’s oxygen content drops to the point where most fish cannot survive, generally between the surface and 700 meters below the surface. The layer has existed for many years; beginning in the middle of the 20th century, oceanographers identified and charted oxygen minimum zones, treating them as stable, rather unusual aspects of deep-ocean chemistry. They weren’t growing very quickly. They weren’t regarded as an urgent ecological emergency. They were a component of the ocean’s background state, found in some basins, significant to scientists researching ocean biogeochemistry, and mostly undetectable…

Restoration crews are working in settings most people don’t identify with post-fire recovery along the Malibu shoreline, where flames have burnt the cliffs and runoff from burned slopes has drowned kelp holdfasts in the shallow sea below. The shore was not the end of the fire destruction. It continued to enter the ocean as trash flows and sediment pulses that covered the rocky substrate where kelp grows and adheres. Restoring the physical conditions necessary for kelp to anchor and thrive is more important for rebuilding those forests than simply planting kelp. Time, consistent funding, and scientific collaboration are necessary for…

individuals’s reactions to sea level rise differ from those of individuals who live inland along Louisiana’s Gulf Coast in areas where the road to the closest grocery store already floods on a typical high tide without any storm in sight. To them, it’s not abstract. It’s the water seeping under the back door in October, the sandbags that are now a permanent feature in garages, and the school system that subtly rearranged the schedule to avoid the twice-weekly flooding on the access road. The NOAA and NASA Sea Level Rise Technical Report quantifies the difficulties these communities are presently facing…

There are models in the offices where federal climate policy is formulated, such as the EPA’s regulatory shop, the interagency groups that determine emissions targets and compute societal costs, and the budget offices that assess the costs of doing nothing. The models provide analysts with information on the amount of warming that a particular level of atmospheric CO2 will produce, the economic harm that warming produces, and consequently the cost to society of each additional ton of CO2 entering the atmosphere. From the initial commitment made in the Paris Agreement to the renewable energy provisions of the Infrastructure Investment and…

When a tracked vehicle travels across the abyssal plain during a deep-sea mining operation in the Clarion-Clipperton Zone, the surrounding seafloor vanishes into a haze. Sediment that has accumulated over millions of years, layer by layer, gets disturbed by the machinery; this is a material archive of geological time that hasn’t been touched since before any extant creature evolved. The cloud does not remain at the bottom. As the car passes by and the suction systems pick up nodules, fine particles are agitated into suspension and start to drift. They are picked up by ocean currents. And what was once…

About 168 miles southwest of the Louisiana coast, the Orca Basin is located in water deep enough that chemistry and pressure have combined to produce something unique: a layer of brine so rich and oxygen-depleted that virtually nothing can break down in it. In contrast to regular seawater, objects that sink into the Orca Basin do not decompose. Biological and chemical deterioration is slowed to a fraction of its typical rate by the anoxic conditions, which are virtually an oxygen desert at the bottom of the Gulf of Mexico. For many years, marine scientists have been aware of this and…

Tanks big enough to test underwater vehicles under controlled conditions that mimic the physical demands of the ocean are located within a facility on the Johns Hopkins Homewood campus in Baltimore. In order to simulate real operating environments, engineers lower instrumented robots into these indoor pools, run navigation algorithms through scenarios, and observe what happens when the software encounters the kinds of disturbances that real ocean deployments produce, such as shifting currents, unexpected physical contact, and sensor noise. The difference between a promising algorithm and a deployable system is measured in real data at this unglamorous activity, which involves repeating…