seabed

The dangers of deep sea mining

April 21, 2025 By EarthWise Leave a Comment

The White House is considering an executive order that would fast-track permitting for deep-sea mining in international waters and allow mining companies to bypass a United Nations-backed review process.

Deep sea mining is the extraction of minerals from the seabed in the deep ocean. Most of the interest is in what are known as polymetallic nodules, which are potato-sized mineral deposits that have built up in layers over thousands of years. They are located several miles below the surface, primarily in what is called the Clarion-Clipperton zone, which is an environmental management area of the Pacific Ocean about halfway between Mexico and Hawaii.

A new multiyear study led by UK’s National Oceanography Center and published in the journal Nature found that the site of a deep-sea mining test in 1979 still showed lower levels of biodiversity than in neighboring undisturbed sites 44 years later.

Much is not known about the undersea nodules. We know that they produce oxygen. If the nodules are removed, will that reduce the amount of oxygen in the deep sea and affect the organisms that live there? If mining occurs, what effect will the metal-containing sediment plumes churned up by the mining process have?

The nodule fields sustain highly specialized animal and microbial communities. More than 20 billion tons of nodules are estimated to lie on the seabed of the Clarion-Clipperton Zone. If large-scale mining takes place, and there is much interest in that happening, it is important to find out what the impact will be on the ocean and its ecosystems because it is likely to be largely irreversible.

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Deep sea mining for rare metals impacts marine life for decades, scientists say

Photo, posted September 4, 2014, courtesy of James St. John via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

The doomsday glacier

October 9, 2024 By EarthWise Leave a Comment

The Thwaites Glacier is an enormous Antarctic Glacier. Its area is larger than that of Florida – in fact, larger than 30 other U.S. states – and it is melting. It has been retreating for 80 years but has accelerated its pace in the past 30. Its shedding of ice into the ocean already contributes 4% of global sea level rise. If it collapsed entirely, it would raise sea levels by more than 2 feet. For this reason, it has been dubbed the Doomsday Glacier.

A team of scientists has been studying it since 2018 in order to better understand what is happening within the glacier. They sent a torpedo-shaped robot to the glacier’s grounding line, which is the point at which the ice rises up from the seabed and starts to float. The underside of Thwaites is insulated by a thin layer of cold water. However, at the grounding line, tidal action is pumping warmer sea water at high pressure as far as six miles under the ice. This is disrupting the insulating layer and is speeding up the retreat of the glacier.

The potential collapse of the glacier is not even the only massive risk it poses. It also acts like a cork, holding back the vast Antarctic ice sheet. If that ice sheet were ever to collapse, sea levels could rise 10 feet.

A critical unanswered question is whether the ultimate collapse of Thwaites Glacier is already irreversible. There are regular heavy snowfalls that occur in the Antarctic which help replenish ice loss. Whether nations’ progress in slowing climate change can change the balance between ice accumulation and ice loss on the glacier remains to be seen.

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‘Doomsday’ glacier set to melt faster and swell seas as world heats up, say scientists

Photo, posted January 3, 2022, courtesy of Felton Davis via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Assessing Human-Caused Wildlife Mortality | Earth Wise

May 31, 2022 By EarthWise Leave a Comment

Bycatch is the fishing industry term used to describe the deaths of non-target fish and ocean wildlife during the fishing process. Some bycatch species are thrown away because regulations prohibit them from being kept. Others are thrown out because they won’t fetch high enough prices. According to some estimates, global bycatch amounts to about 10% of the world’s total catch.

Approximately half of global bycatch is a result of trawling. Trawling is a method of commercial fishing that involves pulling or dragging a fishing net – called a trawl – through the water or across the seabed in hopes of catching fish. Commercial fishing companies favor towing trawl nets because large quantities of fish can be caught. But the method is destructive to the seafloor and leads to the indiscriminate catch of all sorts of species, including whales, dolphins, porpoises, sharks, seals, rays, turtles, and seabirds.

Researchers have developed a new method to assess the sustainable levels of human-caused wildlife mortality. When this method is applied to a trawl fishery in Australia, it shows that the dolphin capture is not sustainable. The study, led by scientists at the University of Bristol in the U.K. and United Arab Emirates University, modeled different levels of dolphin capture, including those reported in logbooks and those reported by independent observers. According to the findings, which were recently published in the journal Conservation Biology, even the lowest recorded dolphin capture rates are not sustainable.

The new approach is extremely adept at assessing human-caused mortality to wildlife, and can be applied to fisheries bycatch, hunting, lethal control measures, or even wind turbine collisions.

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Wasted Catch

Dolphin bycatch from fishing practices unsustainable, study finds

Photo, posted May 18, 2011, courtesy of Pete Markham via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Floating Offshore Wind | Earth Wise

April 21, 2022 By EarthWise Leave a Comment

According to a new report by the Global Wind Energy Council, floating offshore wind technology is on track to grow from a miniscule market to a substantial contribution to the world’s energy supply over the next decade. Furthermore, the United States represents one of the countries with the greatest potential.

Wind power is stronger and steadier in the ocean than on land, so the use of offshore wind is rapidly expanding. However, because most installations are based on fixed structures attached to the sea bottom, they cannot be installed in very deep or complex seabed locations.

Floating offshore wind is based on structures that are anchored to the seabed only by means of flexible anchors, chains, or steel cables. Apart from making it feasible to place wind turbines in deeper and more distant locations, floating turbines and platforms can also be built and assembled on land and then towed to the offshore installation site.

The floating offshore wind industry is currently in a pre-commercial phase but has great potential. Many offshore locations with great potential in terms of their wind resources are unsuitable for conventional installations either because of the depth of the seabed or its complex structure. This is particularly true of the waters off the coasts of California, Oregon, and the Gulf Coast, which otherwise offer excellent wind resources.

There are many issues to deal with in expanding the use of floating offshore wind, including transporting the power to shore and the ability of the local power grids to handle the incoming power. On the other hand, distantly placed floating offshore wind reduces environmental concerns and eliminates issues associated with the visual impact of wind farms for coastal residents.

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What’s the potential of floating offshore wind?

Photo, posted May 10, 2015, courtesy of Olin Gilbert via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The Threat From Thwaites | Earth Wise

January 20, 2022 By EarthWise Leave a Comment

The Thwaites Glacier in Antarctica is the widest glacier in the world. It is about 80 miles across and in places extends to a depth of about 2,600 to 3,900 feet. The glacier is roughly the size of Florida, and it currently contributes 4% of annual global sea level rise as it continues to retreat from a warming ocean.

The International Thwaites Glacier Collaboration is a team of nearly 100 scientists dedicated to studying the glacier. According to the scientists, Thwaites has doubled its outflow speed within the last 30 years. The glacier in its entirety holds enough water to raise global sea levels by over two feet, which would be catastrophic.

A third of the glacier flows more slowly than the rest because it is braced by a floating ice shelf that is held in place by an underwater mountain. The concern is that the brace of ice slowing the glacier may not last for long.

Beneath the surface, warmer ocean water is attacking the glacier from all angles. The water is melting the ice directly beneath the glacier causing it to lose its grip on the underwater mountain. Massive fractures have formed and are growing.

Warm water is also a threat for what is called the grounding zone, which is the area where the glacier lifts off the seabed. There are many possible scenarios under which there could be a major ice loss from the glacier. It is unclear how quickly it could occur. It might take decades, or it could be centuries. The threat is large enough and real enough that continued observation and research is essential.

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The Threat from Thwaites: The Retreat of Antarctica’s Riskiest Glacier

Photo, posted October 16, 2012, courtesy of J. Yungel / NASA Ice via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Carbon Capture In Denmark | Earth Wise

January 11, 2022 By EarthWise Leave a Comment

Denmark has pledged to reduce greenhouse gas emissions 70% by 2030 compared with 1990 levels. The country has also banned oil exploration in Danish waters and plans to phase out offshore drilling in the North Sea by 2050.

Instead of pumping oil from the North Sea, Denmark plans to capture CO2 and store it there. To meet its climate goals, Denmark is investing $2.4 billion in a plan to capture carbon dioxide from its energy and industrial sectors and inject it into the seabed in geological formations that previously held oil and gas deposits.

The first North Sea carbon capture and storage facilities will be put into service in 2025 and will remove nearly half a million tons of emissions from the atmosphere each year. The carbon dioxide will be captured from energy and industrial sectors such as waste incineration and cement production.

There are multiple carbon capture projects underway around the world. Many are directed at so-called direct air capture, which is taking carbon dioxide out of the air once it is already there. In Iceland, a project named “Orca” is extracting CO2 from the air and piping into a processing facility where it is mixed with water and diverted into a deep underground well. Other large direct air capture plants are being built in the U.S. Southwest and in Scotland.

Whether capturing carbon from industrial operations or directly from the air ultimately makes environmental and economic sense remains to be seen. What is driving the development of these technologies is the troubling math that reducing emissions is not happening fast enough to stave off the destructive effects of climate change that will result from global temperatures rising too much.

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Denmark bets on North Sea carbon capture to hit climate goals

Photo, posted July 2, 2018, courtesy of Ansgar Koreng via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A Giant U.S. Offshore Wind Project Begins | Earth Wise

June 22, 2020 By EarthWise Leave a Comment

In recent years, the Bureau of Offshore Energy Management – the agency that oversees energy projects in federal waters – has been granting leases for offshore wind projects in the waters of multiple states on the East Coast. Up until now, none of these leases have actually resulted in the deployment of any wind turbines because the process of gaining approvals, project plans, surveys, funding and other requirements is a long and tortuous one.

In late May, the first offshore wind turbine in U.S. federal waters was installed 27 miles offshore from Virginia. The 6-MW Siemens turbine is one of two turbines making up the Coastal Virginia Offshore Wind pilot project. The pilot project is expected to be operational later this year. This project is the first to receive go-ahead approval by the BOEM.

The CVOW project is a development by Dominion Energy, a Virginia-based utility that operates in 20 states. Dominion’s project will eventually be a 2.64 GW mega-farm that could be the largest offshore wind farm in the world. Construction of the main project is expected to begin in 2024. It will be sited in the seabed of a 112,800-acre lease area. The site is currently being surveyed to determine potential impacts to ocean and sea life.

Dominion Energy has made multiple commitments to emissions reduction and the massive offshore wind farm is an important part of its efforts to meet those commitments. The CVOW pilot project is only the second offshore wind installation in the U.S. The first, the Block Island Wind Farm in Rhode Island, is in state waters and did not require BOEM approval.

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A ‘monumental day’ for US offshore wind as first turbine is installed in federal waters

Photo, posted May 13, 2011, courtesy of the Department of Energy and Climate Change via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.