seaweed

Seaweed and concrete

August 29, 2025 By EarthWise Leave a Comment

Modern civilization is pretty much made of concrete. People use more concrete than any other substance apart from water. But concrete is made from cement, and cement is the source of 10% of all carbon dioxide emissions worldwide.

Researchers at the University of Washington and Microsoft have developed a new kind of concrete made by mixing dried, powdered seaweed with cement. By fortifying cement with seaweed, the global warming potential of the concrete is reduced by 21% without weakening it.

This novel recipe for concrete was developed using machine learning models, arriving upon it in a fraction of the time it would have taken by traditional experimentation.

Producing cement leads to carbon emissions from the fossil fuels used to heat raw materials and from a chemical reaction called calcination that occurs during the production process. Seaweed is a carbon sink that pulls carbon dioxide out of the air and stores it while it grows. By replacing some of cement in concrete, the resultant product has a much smaller carbon footprint.

Machine learning was used to predict the ideal mixture of cement and seaweed to yield concrete with a reduced carbon footprint that still passed mechanical strength tests. Finding the right mixture would have taken 5 years ordinarily, but the machine learning process took only 28 days.

The researchers plan to generalize their work to different kinds of algae and even to food waste or other natural materials in order to create local, sustainable cement alternatives around the world.

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Seaweed-infused cement could cut concrete’s carbon footprint

Photo, posted June 29, 2009, courtesy of Peter Castleton via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Plastic from food waste

April 9, 2025 By EarthWise Leave a Comment

Plastic waste management is a complicated business. Most methods of recycling or breaking down plastic are costly and harmful to the environment. The most common biodegradable alternatives – like paper straws – are less than ideal replacements.

There are many approaches to creating biodegradable plastics using feedstocks like seaweed, sugarcane, and other plant matter. However, the resulting plastics often fall short compared with conventional petroleum-based plastics.

One type of bioplastic that is gaining popularity is polyhydroxyalkanoates, or PHA. PHA is a plastic produced by microorganisms. It is fully compostable or biodegradable but in other ways but looks, feels, and functions like regular plastic but without the environmental drawbacks.

PHA can be made using bacterial fermentation of a variety of feedstocks such as vegetable oils, sugars, starches, and even methane and wastewater.

Researchers at a startup from the University of Waterloo in Canada called MetaCycler BioInnovations have developed a process for producing PHA based on bacteria that has been engineered to convert waste from milk and cheese production. This solution upcycles waste from the dairy industry into cost-effective, sustainable bio-based plastics.

PHAs can be tailored to have a wide range of properties ranging from being rigid and tough to being quite flexible. Therefore, they can be suitable for many applications including packaging, agricultural films, and consumer goods.

The Waterloo technology is a way to tackle the problems of both food waste and plastic pollution with one solution.

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Turning food waste into a new bioplastic

Photo, posted December 10, 2017, courtesy of Leonard J Matthews via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Reducing methane from cattle

December 26, 2024 By EarthWise Leave a Comment

Livestock is responsible for almost 15% of global greenhouse gas emissions. Most of that is in the form of methane that cattle release when they burp. Grazing cattle produce more methane than feedlot cattle or dairy cows because they eat more fiber from grass. There are 9 million dairy cows in the U.S. but more than 64 million beef cattle.

Beef cattle spend most of their lives grazing in pastures and producing methane. Controlling the food of pasture-raised cattle is difficult because they often graze far from ranches for extended periods of time. During the winter and during times when grass is scarce, ranchers supplement the diet of cattle.

A new study by researchers at the University of California – Davis has found that feeding grazing cattle a seaweed supplement in pellet form reduced their methane emissions by nearly 40% without affecting their health or weight. There have been previous studies that showed seaweed cut methane emissions by 82% in feedlot cattle and over 50% in dairy cows. But this is the first study to test the effects of seaweed on grazing beef cattle.

The seaweed pellets were made available to grazing cattle and they ate the supplement voluntarily. Compared to a group of cattle who didn’t receive the supplements, the seaweed eaters had a 40% reduction in methane emissions.

Other research studies to reduce methane emissions using feed additives have taken place in controlled environments with daily supplements. This method provides a way to make a seaweed supplement easily available to grazing animals. It could even be introduced through a lick block for cattle.

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Feeding Grazing Cattle Seaweed Cuts Methane Emissions by Almost 40%

Photo, posted February 18, 2016, courtesy of Beverly Moseley/NRCS via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Wind farms and sea farms

August 5, 2024 By EarthWise Leave a Comment

There has been increasing use of agriculture coexisting with solar farms. This dual use of land is a win-win situation. Recently, Danish researchers have been investigating the potential for farming marine products at offshore wind farms.

Scandinavia’s largest wind farm, Kriegers Flak, is the site of a four-year-old project in which long lines are stretched between the wind farm’s pylons and are used to grow mussels and seaweed. With the first harvest that has taken place after 18 months, it is showing signs of early success.

Seaweed and mussels are low trophic aquaculture crops. That means that that they don’t need to be fed or fertilized. They take up nutrients from the sea and produce healthy foods.

The 328-foot lines spread between the turbines can be used to grow substantial quantities of the underwater seafood. According to modeling by Aarhus University – the institution conducting the study – using just a tenth of Denmark’s wind park area could produce tons of seafood annually while using only the naturally-available resources. This form of aquaculture captures emissions instead of producing them.

Researchers say that it is time to develop guidelines to encourage companies to plan for multiple uses of the ocean because countries are ramping up production of clean energy from offshore wind farms. Denmark was the first country in the world to install a commercial offshore wind park in 1991. Over 30 years later, nearly half of the country’s electricity comes from wind turbines.

The benefits of such sea farms combined with offshore wind farms go beyond food production and clean energy production. They also help improve water quality and capture carbon. It is another win-win situation.

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Beneath offshore wind turbines, researchers grow seafood and seaweed

Photo, posted August 5, 2007, courtesy of Andreas Klinke Johannsen via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Energy efficient cows

April 5, 2024 By EarthWise Leave a Comment

Livestock production – primarily cows – produce nearly 15% of global greenhouse gas emissions, mostly in the form of methane emitted by burping caused by the way they process food. A single cow produces roughly 200 pounds of methane gas per year and there are 1.5 billion heads of cattle in the world.

Researchers at Penn State University have found that supplementing the feed of high-producing dairy cows with the botanical extract capsicum oleoresin – a substance obtained from chili peppers – or a combination of that extract and clove oil resulted in the animals using feed energy more efficiently.

Adding these substances – which are commonly called essential oils – to the cattle’s feed results in improved efficiency of energy utilization. It is known that botanicals have the potential to modify fermentation in the cow’s largest stomach – called the rumen.

There have been previous studies for many years adding substances to dairy cow feed – such as seaweed, garlic, and oregano – in an effort to improve milk production and reduce environmental emissions from dairy farms.

The Penn State study was actually not specifically aimed at methane reduction but rather to better use the available energy from the feed to gain body weight. However, the researchers found that the yield and intensity of methane from the cows in the study were decreased by 11% by the combination of capsicum oleoresin and clove oil.

Botanicals have shown a wide range of anti-microbial properties against bacteria, protozoa, and fungi, as well as being potential rumen modifiers in cattle. The new study represents an interesting approach to improve the metabolism of dairy cows.

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Dairy cows fed botanicals-supplemented diets use energy more efficiently

Photo, posted April 9, 2012, courtesy of Aimee Brown / OSU via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Food and the climate crisis

December 18, 2023 By EarthWise Leave a Comment

Agriculture is a major part of the climate problem and remains one of the hardest human activities to decarbonize. It’s responsible for approximately 25% of global greenhouse gas emissions.

Many experts contend that alternative food sources – like insect farming and seaweed aquaculture – are part of the solution. Additionally, expanding production of climate resilient food crops, including quinoa, kernza, amaranth, and millet, likely also have a role to play.

But according to a new study led by researchers from the University of California – Irvine, another solution to this problem may be to eliminate farms altogether. In the study, which was recently published in the journal Nature Sustainability, the research team explored the potential for wide scale synthetic production of dietary fats through chemical and biological processes. The materials needed for this method are the same as those used naturally by plants: hydrogen (in water) and carbon dioxide (in the air).

The research team highlighted some of the potential benefits of farm-free food, including reduced water use, less pollution, localized food production, and less risk to food production from weather.

Cookies, crackers, chips, and many other grocery products are made with palm oil, a dietary fat that continues to be a major driver of deforestation around the world. However, it remains to be seen how consumers would react if the oil used to bake their cookies came from a food refinery up the road instead of a palm plantation in Indonesia.

According to the researchers, depending on food refineries instead of tropical plantations for dietary fats could mitigate lots of climate-warming emissions while also protecting land and biodiversity.

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UC Irvine-led science team shows how to eat our way out of the climate crisis

Photo, posted July 15, 2008, courtesy of Quinn Dombrowski via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Seaweed On The Way | Earth Wise

April 28, 2023 By EarthWise Leave a Comment

A type of seaweed called sargassum has long formed large blooms in the Atlantic Ocean. It gets its name from the Sargasso Sea in the western Atlantic. Since 2011, scientists have been tracking massive accumulations of the stuff each year that starts out off the coast of Africa and works its way across the Atlantic to end up in the Gulf of Mexico.

The amount of sargassum present each year can shift depending on factors like changes in nutrients, rainfall, and wind conditions. But since the 1980s, nitrogen content in the Atlantic has gone up by 45%. This is likely due to human activities such as agriculture and fossil fuel production dumping materials into the rivers that feed into the ocean.

According to recent observations, the mass of seaweed now heading for Florida and other coastlines throughout the Gulf of Mexico may be the largest on record. The giant blob of sargassum spans more than 5,000 miles in extent. It is moving west and will pass through the Caribbean and up into the Gulf during the summer. The seaweed is expected to become prevalent on beaches in Florida around July.

The seaweed provides food and protection for fishes, mammals, marine birds, crabs, sea turtles, and more. But unfortunately, when sargassum hits the beaches, it piles up in mounds that can be difficult to walk through and eventually emits a gas that smells like rotten eggs.

Tourist destinations in the Caribbean region have their work cut out for them to remove seaweed that can pile up several feet deep. For example, in Barbados, locals were using 1,600 dump trucks a day to clean their beaches. Caribbean and Florida resorts spend millions of dollars each year to remove sargassum seaweed.

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A 5,000-mile-wide blob of seaweed is headed for Florida, threatening tourism across the Caribbean

Photo, posted February 24, 2020, courtesy of Bernard Dupont via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Insects On The Menu | Earth Wise

March 6, 2023 By EarthWise Leave a Comment

According to the World Food Programme, a record 349 million people across 79 countries are facing acute food insecurity. This constitutes a staggering rise of 200 million people compared to pre-pandemic levels. Nearly one million people globally are fighting to survive in famine-like conditions, which is ten times more people than just five years ago.

As a result, many experts contend that alternative or so-called novel food sources – such as lab-grown meats, seaweed aquaculture, and insects – will be necessary to help fight global hunger and global food insecurity.

Insects already form a significant part of diets in many cultures around the world. Insects are great sources of nutrients, including protein, vitamins, and minerals. But insects have yet to be embraced in any substantial way in western cultures… but that may be changing.

In fact, the European Union has now certified four types of bugs as food fit for human consumption. The larvae of lesser mealworms and house crickets recently became the third and fourth insects approved for sale as food in the EU, joining yellow mealworms and grasshoppers. Eight more applications are awaiting approval.

Insects are already a delicacy in many high-end restaurants around the world, and a normal and healthy part of diets in countries like Mexico and Thailand. Embracing insects as a food of the future will not only help in the fight against global hunger, but will also help to reduce greenhouse gas emissions and to slow species extinction.

In Western food markets, the so-called “yuck factor” remains the biggest hurdle to cross. But as the world population grows, the need for sustainable solutions in the food industry grows with it.

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Insects on the menu as EU approves two for human consumption

World Hunger Surged in 2020, U.N. Says

A global food crisis

Photo, posted April, 2014, courtesy of Shankar S. via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Feeding Cows Seaweed | Earth Wise

July 15, 2022 By EarthWise Leave a Comment

When cows digest their food, they burp, and when they burp, they release methane. This is called enteric methane and it’s a real problem. A single cow belches out 220 pounds of methane each year, which is the greenhouse gas equivalent of burning over 900 gallons of gasoline. That’s more than the average car uses in a year.

Several studies have shown that feeding cows seaweed has the potential to substantially reduce the amount of methane in cow burps. The latest comes from a trial that took place at the Straus Family Creamery, an organic dairy producer in Marin County, California.

The trial used a new seaweed-derived feed additive called Brominata. Brominata is made of a red seaweed called Asparagopsis taxiformis. The addition of the seaweed to the cows’ diets on the Straus farm resulted in an 52% average reduction in enteric methane emissions. One cow in the study showed a reduction of 92%.

Cutting enteric methane emissions in half would be a huge improvement that would be quite difficult to achieve by convincing enough people to reduce meat and dairy consumption.

The California Air Resources Board has identified feed additives as an emissions-reduction strategy for the dairy industry. There are now some synthetic feed additives that have been developed that reduce enteric methane, but they haven’tyet received FDA approval for use in the U.S. Brominata has been approved as Generally Regarded as Safe by the California Food and Drug Administration. Whether it and similar seaweed-based feeds can be produced in sufficient quantity and without adverse environmental effects remains to be seen. But it is an intriguing approach to solving a complicated problem.

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Feeding Cows Seaweed Reduces Their Methane Emissions, but California Farms Are a Long Way From Scaling Up the Practice

Photo, posted November 10, 2015, courtesy of Lance Cheung/USDA via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Removing Carbon With The Oceans | Earth Wise

January 26, 2022 By EarthWise Leave a Comment

There is increasing concern that reducing carbon emissions alone will not be sufficient to stabilize the climate and that technologies that actively remove carbon dioxide from the air will be needed. There has been a fair amount of analysis of the efficacy of storing carbon in agricultural soil and in forests, but there has not been comparable studies of the risks, benefits, and trade-offs of ocean-based strategies.

The oceans currently absorb about a quarter of the world’s carbon dioxide emissions. There are multiple ways in which oceans could be induced to store much more. A new report from the National Academies of Sciences, Engineering, and Medicine looks at several ocean carbon dioxide removal strategies in terms of efficacy, potential costs, and potential environmental risks.

One approach involves adding nutrients to the ocean surface to increase photosynthesis by phytoplankton. The approach has a medium to high chance of being effective and has medium environmental risks.

Another approach is large-scale seaweed farming that transports carbon to the deep ocean or into sediments. It has medium efficacy chances but higher environmental risks.

Protection and restoration of coastal ecosystems including marine wildlife would have the lowest environmental risk but only low to medium efficacy.

Chemically altering ocean water to increase its alkalinity in order to enhance reactions that take up carbon dioxide would be highly effective but a medium environmental risk.

The report describes some other approaches as well. It recommends a $125 million research program to better understand the technological challenges as well as the potential economic, social, and environmental impacts of increasing the oceans’ absorption of carbon dioxide.

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Oceans Could Be Harnessed to Remove Carbon From Air, Say U.S. Science Leaders

Photo, posted August 21, 2016, courtesy of Quinn Dombrowski via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The World’s Largest Harmful Algal Bloom | Earth Wise

July 1, 2021 By EarthWise Leave a Comment

Brown sargassum seaweed floats in surface water in a bloom that stretches all the way from West Africa to the Gulf of Mexico. Sargassum provides habitat for turtles, crabs, fish, and birds.

The stuff carpets beaches along the tropical Atlantic, the Caribbean Sea, the Gulf of Mexico, and the east coast of Florida disrupting tourism. Florida’s Miami-Dade County alone spends $45 million a year cleaning up sargassum. Annual Caribbean clean-up is in excess of $120 million.

A study by Florida Atlantic University has discovered dramatic changes in the chemistry and composition of sargassum which has transformed the so-called Great Atlantic Sargassum Belt into a toxic dead zone.

The findings of the study suggest that increased nitrogen availability from both natural and human-generated sources, including sewage, is supporting blooms of sargassum and turning a critical marine nursery habitat into harmful algal blooms with catastrophic impacts on coastal ecosystems, economies, and human health.

The study found that today’s sargassum tissues compared with those of the 1980s have 35% more nitrogen content and 42% less phosphorus. Much of the nitrogen increase is a result of agricultural and industrial runoff from the Congo, Amazon, and Mississippi Rivers.

The fact that the bloom itself has expanded so tremendously was already suspected to be the result of significant changes in the ocean’s chemistry. Given the negative effect that the Great Atlantic Sargassum Belt is having on the coastal communities, additional research is essential to guide mitigation and adaptation efforts.

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Sargassum now world’s largest harmful algal bloom due to nitrogen

Photo, posted June 5, 2016, courtesy of J Brew via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Sea Turtles And The Sargasso Sea | Earth Wise

June 15, 2021 By EarthWise Leave a Comment

The lifecycle of sea turtles includes a longstanding mystery, often called the “lost years”. Turtles hatching from nests along Florida’s Atlantic coast head into the ocean and are generally not seen again for several years before they return in their adolescence. Very little is known about where they spend this time in the open ocean.

Researchers at the University of Central Florida have learned that green turtles as well as loggerhead turtles – both iconic species in conservation efforts – may be spending their youth in the legendary Sargasso Sea. The Sargasso Sea is located off the east coast of the U.S. in the North Atlantic Ocean. It has frequently been featured in popular culture, such as in the novel Twenty Thousand Leagues Under the Sea, as a place where ships could be trapped in thick mats of floating, brown Sargassum seaweed for which the sea is named.

The researchers tracked the baby turtles by attaching advanced, solar-powered tracking devices, about an inch long, to their shells. They used a special adhesive that held the devices to the turtle shells but would allow the devices to fall off after a few months causing no harm to the turtles or inhibiting shell growth or behavior.

It was previously thought that baby turtles would passively drift in sea currents and simply ride those currents until their later juvenile years. The new research shows that the turtles actively orient to go into the Sargasso Sea.

Studies of where turtles go as they develop are fundamental to sound sea turtle conservation. If we don’t know where turtles are and what parts of the ocean are important to them, we are doing conservation blindfolded.

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Legendary Sargasso Sea May be Sea Turtles’ Destination during Mysterious ‘Lost Years’

Photo, posted October 23, 2016, courtesy of Kris-Mikael Krister via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The Collapse of Northern California Kelp Forests | Earth Wise

March 30, 2021 By EarthWise Leave a Comment

For thousands of years, thick canopies of kelp formed an underwater forest spanning the coast of Northern California. Kelp is the cornerstone of a rich subtidal community, providing food and habitat for all sorts of marine creatures. But in recent years, a shocking transformation has occurred. Satellite imagery reveals that the area covered by kelp forests off the coast of Northern California has declined by more than 95%. Only a few small, isolated patches remain.

In a new study, researchers at the University of California Santa Cruz found that the kelp forest decline was an abrupt collapse as opposed to a gradual decline.

According to the study, which was recently published in the journal Communications Biology, kelp forests north of San Francisco were resilient to warming events in the past, like El Niños and marine heatwaves. But the decline of a key sea urchin predator – the sunflower sea star – from sea star wasting disease caused the kelp forests’ resiliency to plummet. Sea urchins are voracious consumers of kelp.

But it was a series of events – not just the sea urchins – that combined to decimate the Northern California kelp forest. A marine heatwave that became known as “the blob” developed in 2014 and moved down the West Coast in 2015. Around the same time, a strong El Niño event developed and brought warmer water up the coast from the south. The warming ocean waters combined with the ravenous sea urchin population resulted in the dramatic decline of kelp.

According to researchers, the prospects for a Northern California kelp forest recovery remain poor unless sea urchin predators return to the ecosystem.

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The collapse of Northern California kelp forests will be hard to reverse

Photo, posted August 13, 2019, courtesy of Sara Hamilton of OSU College of Science via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The First Earth Fund Awards | Earth Wise

December 25, 2020 By EarthWise Leave a Comment

Last February, Amazon CEO Jeff Bezos announced that he was launching the Bezos Earth Fund that would grant money to scientists, activists, NGOs and others making an effort to help preserve and protect the natural world. The fund would start out with $10 billion and would begin issuing grants later in the year.

In November, the first Earth Fund award recipients were announced. In total, 16 organizations will be receiving nearly $800 million in funding.

The largest awards include the following: the Environmental Defense Fund received $100 million to build and launch MethaneSAT, a satellite that will locate and measure sources of methane pollution around the world and provide public access to data that assures accountability.

The Natural Resources Defense Council was awarded $100 million to advance climate solutions and legislation at the state level, promote policies and programs focused on reducing oil and gas production, protect and restore ecosystems that store carbon, and accelerate sustainable and regenerative agriculture practices.

The Nature Conservancy also received $100 million and plans to use the money to help protect the Emerald Edge forest. (That is the largest intact coastal rainforest on Earth, spanning 100 million acres through Washington, British Columbia and Alaska).

The World Resources Institute will receive $100 million, doled out over five years, to be used to develop a satellite-based monitoring system to advance natural climate solutions around the world.

An additional $100 million award went to the World Wildlife Fund to help protect and restore mangroves, develop new markets for seaweed as an alternative to fossil fuel-based products, and to protect forests and other ecosystems around the world.

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The organizations that will benefit from Bezos’ $791M and what will they do with the money

Photo, posted March 4, 2015, courtesy of Kevin Gill via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Foods of the Future? | Earth Wise

March 27, 2020 By EarthWise Leave a Comment

In a world where many go hungry in the context of rapidly changing environments, many experts contend that alternative food sources will be necessary to solve global food security problems. So-called novel food sources are central to this conversation, defined as foods with no history of consumption in a region – or perhaps anywhere.

Three popular examples are lab-grown meat, insect farming, and seaweed aquaculture. Each of these offer opportunities as well as challenges.

Lab-grown meat can refer to actual animal tissues raised in vats as well as the increasingly common cultured plant products made to resemble meat. Lab-grown meat faces push back from the livestock industry that contends it should not be labeled as any kind of meat. While results to date are positive, barriers still remain including concerns over product taste, healthiness, and cost. And while less land- and water-intensive than conventional livestock, cultured meat production is still energy intensive.

Insects do form a significant part of diets across the globe but have yet to be embraced in any substantial way in western cultures. Nutritionally, numerous species of insects are rich in key proteins, micronutrients, and minerals. But the “yuck factor” is a big barrier to cross.

Seaweed is a long-established part of many East Asian diets and has many potential dietary uses. Several selectively bred varieties of seaweed supply a range of valuable nutrients. Growing seaweed does not tax freshwater and terrestrial resources. But intensively cultivated seaweeds would have potential negative effects on local marine ecosystems.

There is no single solution to complex issues like food security. Novel foods may very well form part of the solution to a growing food crisis.

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Insects, seaweed and lab-grown meat could be the foods of the future

Photo, posted March 12, 2009, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Mistaking Plastic For Food

September 27, 2019 By EarthWise Leave a Comment

Green sea turtles are one of the world’s largest species of turtle, with some measuring close to four feet long and weighing up to nearly 300 pounds. Their range extends throughout tropical and subtropical seas around the world, with the largest nesting populations found in Costa Rica and Australia.

Green sea turtles get their name from the green layer of fat under their shell, as opposed to their shell itself, which can be brown, green, yellow, and/or black. Scientists believe the green coloring of their fat is a result of their diet. Unlike most other sea turtles, green sea turtles eat marine plants such as seaweed and seagrass.

But new research suggests that green sea turtles are also more likely to swallow plastic because it resembles their natural diet. The scientists from the University of Exeter and the Society for the Protection of Turtles who examined green sea turtles that washed up on beaches in Cyprus found they favored narrow lengths of plastic in natural colors (like green and black) as opposed to debris of other shapes and colors.

Researchers were able to examine the full gastrointestinal tract of 19 green sea turtles. They found pieces of plastic inside every one of them, with the number of pieces ranging from three to 183. Smaller turtles tended to contain more plastic, possibly because they are less experienced or because diet choices change with age and size.

Previous research has suggested that leatherback sea turtles also eat plastic that resembles their food: jellyfish.

Researchers hope these findings will help motivate us to continue to work on reducing our overall plastic consumption and pollution.

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Green turtles eat plastic that looks like their food

Photo, posted September, 2007, courtesy of Brock Roseberry via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A Giant Seaweed Bloom

August 19, 2019 By EarthWise Leave a Comment

Scientists using data from NASA satellites have discovered and documented the largest bloom of seaweed in the world, stretching all the way from West Africa to the Gulf of Mexico. The gigantic macroalgae bloom has been dubbed the Great Atlantic Sargassum Belt.

The brown seaweed floats in surface water and in recent years has become a problem to shorelines lining the tropical Atlantic, Caribbean Sea, Gulf of Mexico, and east coast of Florida. The stuff carpets popular beach destinations and crowded coastal waters. In 2018, more than 20 million tons of it floated on the ocean surface.

Scientists have been studying the Sargassum algae using satellites since 2006, but the major blooms have only started appearing since 2011. They have occurred every year between 2011 and 2018 except for 2013. Before 2011, most of the free-floating Sargassum in the ocean was primarily found in patches around the Gulf of Mexico and the Sargasso Sea located on the western edge of the central Atlantic Ocean.

Sargassum provides habitat for turtles, crabs, fish and birds, and produces oxygen via photosynthesis. However, too much of it can crowd out many marine species.

According to researchers, the ocean’s chemistry must have changed in order for the bloom to get so out of hand. The factors involved include a large seed population left over from a previous bloom, nutrient input from West Africa, and nutrient input from the Amazon River. The increase in nutrients may be a result of deforestation and fertilizer use.

Climate-change effects on precipitation and ocean currents ultimately do play a role in this, but increased ocean temperatures do not. Unfortunately, these giant seaweed blooms are probably here to stay.

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NASA Satellites Find Biggest Seaweed Bloom in the World

Photo courtesy of NASA.

Earth Wise is a production of WAMC Northeast Public Radio.

Sustainable Plastics

January 28, 2019 By EarthWise Leave a Comment

According to the United Nations, plastic accounts for up to 90% of all the pollutants in the ocean. Conventional plastics take hundreds of years to decay, so all the plastic that gets into the oceans piles up and endangers marine life and pollutes the environment. Unfortunately, there are few comparable, environmentally friendly alternatives.

An often-proposed solution is bioplastics, which are not made from petroleum and degrade quickly. The downside of bioplastics is that growing the plants or bacteria used to make the plastic requires fertile soil and fresh water, which are scarce commodities in many places.

One such place is Israel. So, researchers there at Tel Aviv University have developed a process to make a bioplastic polymer that doesn’t require land or fresh water. The new polymer is derived from microorganisms that feed on seaweed. It is biodegradable, produces zero toxic waste and recycles into organic waste.

The polymer is called polyhydroxyalkanoate, or PHA for short. The raw material is multicellular seaweed, cultivated in the ocean. These algae are eaten by single-celled microorganisms, which also grow in salty seawater and produce a polymer that can be used to make bioplastic. PHA is already produced in commercial quantities, but it is currently made from plants that require agricultural land and fresh water. The new process would enable countries with limited fresh water, such as Israel, China and India, to switch from petroleum-based plastics to biodegradable plastics.

Plastics from fossil sources are one of the world’s biggest pollution problems. The new study shows that it is possible to produce bioplastic completely based on marine resources in an environmentally-friendly process.

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