Philippa Kaur

Schistosomiasis, one of the most common human parasitic diseases, is a global menace because of its high rates of infection and contribution to poverty. Over the past two decades, global campaigns using antiparasitic medication have been carried out to combat the scourge of the disease. In 2022, the World Health Organization released guidelines1 to further expand the scale of these mass-treatment campaigns, with the goal of eliminating schistosomiasis as a public-health problem by 2030. Although this strategy has yielded clear public-health benefits2, the following key question remains: what solutions can be devised to further combat schistosomiasis and forge a sustainable future? Writing in Nature, Rohr et al.3 identify an innovative and transdisciplinary solution to reduce cases of schistosomiasis.
Competing Interests
N.C.L. reports personal fees from the World Health Organization related to work on public-health guidelines for schistosomiasis. More

Phytoplankton bloom off the coast of France in 2004. The greener ocean colour over the past 20 years might be related to increased phytoplankton activity.Credit: NASA/AFP via Getty

More than half of the world’s oceans have become greener in the past 20 years, probably because of global warming. The discovery, reported today in Nature1, is surprising because scientists thought they would need many more years of data before they could spot signs of climate change in the colour of the oceans.“We are affecting the ecosystem in a way that we haven’t seen before,” says lead author B. B. Cael, an ocean and climate scientist at the National Oceanography Centre in Southampton, UK.The ocean can change colour for many reasons, such as when nutrients well up from its depths and feed enormous blooms of phytoplankton, which contain the green pigment chlorophyll. By studying the wavelengths of sunlight reflected off the ocean’s surface, scientists can estimate how much chlorophyll there is and thus how many living organisms such as phytoplankton and algae are present. In theory, biological productivity should change as ocean waters become warmer with climate change.But the amount of chlorophyll in surface waters can vary markedly from year to year, making it hard to differentiate any changes induced by climate change from the big natural swings. Scientists thought it might take up to 40 years of observations to spot any trends2.Another complicating factor is that numerous satellites have measured ocean colour over time, and each did so in a slightly different way, so the data cannot be combined. Cael’s team decided to analyse data from MODIS, a sensor aboard NASA’s Aqua satellite, which was launched in 2002 and is still orbiting Earth, far surpassing its anticipated six-year lifetime. The researchers looked for trends in seven different wavelengths of light from the ocean, rather than sticking with the single wavelength used to track the often-used single measure of chlorophyll. “I’ve thought for a long time that we could do better by looking at the full colour spectrum,” Cael says.With two decades of MODIS data, the scientists were able to see long-term changes in ocean colour. They observed notable shifts in 56% of the world’s ocean surface, mostly in the waters between the latitudes of 40º S and 40º N. These tropical and subtropical waters generally don’t vary much in colour throughout the year, because the regions don’t experience extreme seasons — and so small long-term changes are more apparent there, Cael says.The intensity of the colour change depends on the wavelength of light measured. In general, the waters are becoming greener over time.To see if the shifts could be linked to climate change, the researchers compared the observations to the results of a model3 that simulated how marine ecosystems might respond to increasing levels of greenhouse gases in the atmosphere. The observed changes matched those in the model.Shades of greenNow, the question is what is turning the oceans greener. It’s probably not a direct effect of increasing sea surface temperatures, Cael says, because the areas where colour change was observed do not match up with those where temperatures have generally risen. One possibility is that the shift might have something to do with how nutrients are distributed in the ocean. As surface waters warm, the upper layers of the ocean become more stratified, making it harder for nutrients to rise to the surface. When there are fewer nutrients, smaller phytoplankton are better at surviving than larger ones, and so changes in nutrient levels could lead to changes in the ecosystem that are reflected in changes in the water’s overall colour.But this is just one idea; the researchers can’t yet say exactly why the changes are happening. “The reason we care about the colour is because the colour tells us something about what’s happening in the ecosystem,” Cael says.The discovery ramps up expectations for the next big mission to monitor ocean colour — NASA’s Plankton, Aerosol, Cloud, ocean Ecosystem (PACE) satellite. Set to launch in January 2024, PACE will measure ocean colour in many more wavelengths than any previous satellite, a capability known as ‘hyperspectral’.“All of this definitely confirms the need for global hyperspectral missions such as PACE,” says Ivona Cetinić, an oceanographer at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, who works on PACE. The spacecraft “should allow us to understand the ecological implications of the observed trends in ocean ecosystem structure in years to come.” More

RESEARCH BRIEFINGS
12 July 2023

Extensive fieldwork reveals that island plants have similar functions to plants in other regions of the world, but that the island environment, along with biogeographical and evolutionary processes, filters the life-history characteristics and strategies of the plants, rendering the island flora functionally and ecologically distinct from others. More

A survey of 84 coral ecosystems at 25 locations across the Pacific, Atlantic and Indian ocean basins found plastic debris from human activities in almost all of them, both shallow and deep.The study team, led by marine biologist Hudson Pinheiro at the University of São Paulo, Brazil, set out to survey biodiversity on remote reefs, which the researchers expected to be pristine. But during their sampling, they noticed that “these places are not as pristine as we were thinking”, Pinheiro says. It turned out that 77 of the 84 ecosystems contained macroplastics — plastic items measuring 5 centimetres or more across. The researchers found that this type of plastic waste made up 88% of all human-generated rubbish on the reefs1.Much of the debris found in the more remote locations was discarded fishing gear — including nets, hooks and lines. In some places, the team found evidence of “ghost fishing”, in which discarded fishing nets become stuck in the reefs and continue to trap and kill fish.

An old shoe lodged among corals on a reef near the Philippines.Credit: Luiz A. Rocha, California Academy of Sciences

In non-reef marine ecosystems, artificial plastic waste is usually concentrated near the surface and consists mostly of consumer items. But reefs are different — Pinheiro and his colleagues found that deeper reefs contained more macroplastics than shallow ones. There could be several reasons for this: strong waves can carry plastic away from shallow reefs or push it to the depths, for example. And clean-up efforts to remove plastic happen mainly on shallow reefs.

Marine organisms live alongside waste plastic even at a depth of 130 metres.Credit: Luiz A. Rocha, California Academy of Sciences

The deeper reefs are home to abundant fish species, which might explain why fishing nets and gear dominate the litter in these ecosystems, the authors say. As fewer and fewer fish are found in shallower waters, deep-sea fishing is becoming more common, and the amount of refuse could reflect this. “The fishermen are needing to get further away from shore, to fish in deeper reefs because of the pollution and degradation of the shallow reefs,” says Pinheiro.

Fishing lines tangled in a 100-metre-deep reef in the western Pacific.Credit: Luiz A. Rocha, California Academy of Sciences

The plastic waste can damage coral ecosystems in a number of ways. Ropes and nets can get tangled up in coral and cause breakages when fishers try to retrieve them. Plastic debris can also harbour bacteria and other microorganisms that can damage the coral. “Other studies have associated the presence of plastics with coral disease,” says Pinheiro.

A plastic bag drifts around one of Oman’s coral reefs.Credit: Tane Sinclair-Taylor

With negotiations under way for the United Nations global plastics treaty to end plastic pollution, thought needs to be given to how this kind of deep-reef pollution can be eliminated. “We are not talking about going to a supermarket and you change a plastic bag for a paper bag, we’re talking about people that depend on catching their food,” says Pinheiro, who urges negotiators to consider discussing subsidies and other incentives to help fishers to use less plastic, or developing biodegradable materials that could help put an end to contamination of the deepest coral reefs. More

Powerful vested interests are threatening the adoption of the proposed European Union Nature Restoration Law. The law would require restoration measures to be in place on 20% of Europe’s land and sea area by 2030, and aims to make the continent’s rivers, agriculture, forests and cities more biodiverse and resilient. The European Commission calculates that between 8 (US$9) and 38 will be returned in ecosystem services for every euro invested in restoration.Voting to pass the law takes place this month in the European Parliament. Opponents are influenced by lobbyists in favour of intensive agriculture, fisheries and the forestry industry, who say that the law would cut jobs and undermine food and energy security (see, for example, go.nature.com/3nhboyr; go.nature.com/44bfn8o; go.nature.com/3reitid). The political debate mostly disregards the law’s importance for mitigating and adapting to climate change.Time is short. The scientific community must fend off opposition by publicly debunking misinformation from lobbyists. The EU cannot reconcile a failure to approve the law with its calls for developing countries to stop clearing their pristine lands. More

The European Reference Genome Atlas (ERGA) aims to coordinate the production of high-quality genome sequences that represent eukaryotic biodiversity in Europe. As part of the Earth BioGenome Project, it will foster the widespread use of genomic resources for biodiversity protection, restoration and conservation.
Competing Interests
The authors declare no competing interests. More

I am passionate about the environment and everything related to it. My career path has included entrepreneurship and software development. But my first entry into conservation work was at National Geographic, where I learnt how technology can help with tangible problems, such as tracking elephant migration.In 2018, I joined EarthRanger, a technology platform now owned by the Allen Institute for AI in Seattle, Washington. EarthRanger collects, integrates and displays data and combines them with field reports on everything from animal traps to landslides. The platform has nearly 100 hardware and software data sources, including acoustic sensors and vehicle trackers. Conservationists can see a map with a unified, real-time view of relevant data, from positions of collared wildlife to observations from rangers. Before EarthRanger, these data were recorded on paper or spread across databases.I oversee the platform and develop the software. I spend a lot of time in the field with our partners, which include more than 400 organizations. I work with teams that track animals, study ecosystems and promote human–wildlife coexistence.One of our founding partners is Save the Elephants, based in Samburu, Kenya. It tracks hundreds of elephants across Africa and uses EarthRanger to monitor their locations.In this picture, I’m at the Save the Elephants headquarters. I’m surrounded by the skulls and jaws of elephants that have died from both natural and unnatural causes. It’s a remarkable place to reflect. It reminds you of the magnitude and urgency of the problem we’re facing.One elephant dying is a tragedy, and local interventions are needed to prevent more deaths. Tens of thousands dying is an existential risk. Mitigating that risk requires coordinated actions across many communities, organizations and governments. More

A TEPCO representative measures radiation levels around the treated water storage tanks in 2018.Credit: Kimimasa Mayama/AFP via Getty

Despite concerns from several nations and international groups, Japan is pressing ahead with plans to release water contaminated by the 2011 meltdown of the Fukushima Daiichi nuclear power plant into the Pacific Ocean. Starting sometime this year and continuing for the next 30 years, Japan will slowly release treated water stored in tanks at the site into the ocean through a pipeline extending one kilometre from the coast. But just how safe is the water to the marine environment and humans across the Pacific region?How is the water contaminated?The power station exploded after a devastating earthquake and subsequent tsunami crippled the coastal plant, overheating the reactor cores. Since then, more than 1.3 million cubic metres of seawater have been sprayed onto the damaged cores to keep them from overheating, contaminating the water with 64 radioactive elements, known as radionuclides. Of greatest concern are those that could pose a threat to human health: carbon-14, iodine-131, caesium-137, strontium-90, cobalt-60 and hydrogen-3, also known as tritium.Some of these radionuclides have a relatively short half-life and would already have decayed in the 12 years since the disaster. But others take longer to decay; carbon-14, for example, has a half-life of more than 5,000 years.How are they treating the water?The contaminated water has been collected, treated to reduce the radioactive content and stored in more than 1,000 stainless steel tanks at the site. The power-station operator, Tokyo Electric Power Company (TEPCO), so far has used what it describes as an advanced liquid-processing system (ALPS) to treat the water. TEPCO says the water undergoes five processing stages of co-sedimentation, adsorption and physical filtration. The plan for disposing of the radioactive waste created in the ALPS process will be “gradually revealed as the decommissioning process progresses”, according to communication the Permanent Mission of Japan to the International Organizations in Vienna sent to the International Atomic Energy Agency (IAEA).The ALPS process removes enough of 62 of the 64 radionuclides to bring their concentration below Japan’s 2022 regulatory limits for water to be discharged into the environment. These limits are based on recommendations from the International Commission on Radiological Protection.But that process does not remove carbon-14 and tritium, so the treated water needs to be diluted further to less than one part per 100 parts of seawater. TEPCO says that the resulting concentration of tritium is around 1,500 becquerels (a measure of the radioactivity of a substance) per litre — around one-seventh of the World Health Organization’s guidelines for tritium in drinking water. The company suggests that the concentration of tritium will drop to background ocean levels within a few kilometres of the discharge site. The carbon-14 in the tanks is currently at concentrations of around 2% of the upper limit set by regulations, TEPCO says, and this will reduce further with the seawater dilution that takes place before the water is discharged.Jim Smith, an environmental scientist at the University of Portsmouth, UK, says the risk this poses to nations around the Pacific Ocean will probably be negligible. “I always hesitate to say zero, but close to zero,” he says. “The nearest Pacific island is about 2,000 kilometres away.” He argues that a greater risk is posed by keeping the treated water on-site. “The risk of another earthquake or a typhoon causing a leak of a tank is higher, and they’re running out of space.”Will radioactivity concentrate in fish?Nations such as South Korea have expressed concern that the treated water could have unexplored impacts on the ocean environment, and a delegation from the country visited the Fukushima site in May. Last year, the US National Association of Marine Laboratories in Herndon, Virginia, also voiced its opposition to the planned release, saying that there was “a lack of adequate and accurate scientific data supporting Japan’s assertion of safety”. The Philippine government has also called for Japan to reconsider releasing the water into the Pacific.“Have the people promoting this going forward — ALPS treatment of the water and then release into the ocean — demonstrated to our satisfaction that it will be safe for ocean health and human health?” asks Robert Richmond, marine biologist at the University of Hawaii at Manoa. “The answer is ‘no’.”Richmond is one of five scientists on a panel advising the Pacific Islands Forum, an intergovernmental organization made up of 18 Pacific nations including Australia, Fiji, Papua New Guinea and French Polynesia. The panel was convened to advise on whether the release of the treated water from Fukushima was safe both for the ocean and for those who depend on it. Richmond says they have reviewed all the data provided by TEPCO and the Japanese government, and visited the Fukushima site, but there are still some unanswered questions about tritium and carbon-14.Tritium is a β-radiation emitter — albeit a weak one — meaning that it emits ionizing radiation that can damage DNA. TEPCO says the concentrations of tritium in the treated water release a dose of ionizing radiation lower than that experienced by someone flying a round trip from New York to Tokyo.But human skin partly blocks ionizing radiation, Richmond says. “If you eat something that’s radioactively contaminated with β-emitters, your cells inside are being exposed.”TEPCO says fishing is not routinely conducted in an area within 3 kilometres of where the pipeline will discharge the water. But Richmond is concerned the tritium could concentrate in the food web as larger organisms eat smaller contaminated ones. “The concept of dilution as the solution to pollution has demonstrably been shown to be false,” Richmond says. “The very chemistry of dilution is undercut by the biology of the ocean.”Shigeyoshi Otosaka, an oceanographer and marine chemist at the Atmospheric and Ocean Research Institute of the University of Tokyo says that the organically bound form of tritium could accumulate in fish and marine organisms. He says international research is investigating the potential for such bioaccumulation of the radionuclides in marine life, and what has already happened in the waters around Fukushima after the accidental release of contaminated water during the tsunami. “I think it is important to evaluate the long-term environmental impact of these radionuclides,” Otosaka says.A spokesperson for TEPCO said that the company has been conducting tests in which marine organisms are raised in seawater containing ALPS-treated water. “We have confirmed that the tritium concentrations in the bodies of marine organisms reach equilibrium after a certain period of time and do not exceed the concentrations in the living environment,” the spokesperson said. The tritium concentrations then decrease over time once the organism is returned to untreated seawater.TEPCO will continue to compare the health of organisms reared in diluted treated water with those reared in untreated seawater.Has this been done before?Smith points out that releasing tritium-contaminated water is part of the usual operating procedure for nuclear power plants. He says that both the Heysham nuclear power station and Sellafield nuclear-fuel-processing plant in the United Kingdom release between 400 and 2,000 terabecquerels of tritium into the ocean each year. “Overall, because it’s such a weak β-emitter, it’s not really that radiotoxic,” Smith says.Otosaka says that is also the case in Japan: “More than 50 terabecquerel of tritium was discharged annually from each nuclear power plant in regular operation before the accident,” he says. TEPCO says that less than 22 terabecquerels of tritium will be released from the pipeline each year. “The release rate of the tritium … is well controllable,” Otosaka says.TEPCO says there will be continuous monitoring of sea life and sediments around the area, which will be done by TEPCO, the Japanese Nuclear Regulation Authority and the IAEA.The IAEA, which has been supervising the clean-up and management of Fukushima, is expected to release a final report on the site and the plan for the wastewater release later in June. More