food source

A common plant could be a valuable food source

April 4, 2024 By EarthWise Leave a Comment

A new study by researchers at Penn State University has found that a common water plant in the eastern U.S. could be a valuable green fertilizer, a feed for poultry and livestock, and even a life-saving food for people in the event of a catastrophe or disaster.

The plant is the Carolina azolla. It is sometimes called mosquito fern, fairy moss, or water fern. It is a water plant that grows very rapidly; it can double its biomass in two days. There are many varieties of azolla, but the Carolina strain is more digestible and nutritious for people than any of the others.

Azolla species have been used across the world for centuries as a livestock feed and as a fertilizer. They have not been good for human consumption because of high polyphenolic content, which can be 10 times more than that of common food plants. Polyphenols are abundant compounds in many plants and, in low concentrations, are beneficial antioxidants. But in high concentrations they act as antinutritional agents.

It turns out that the Carolina azolla – described as having a crisp texture and neutral taste – has a polyphenolic content comparable to many fruits, nuts, and vegetables. Furthermore, cooking significantly decreases the polyphenolic content in foods.

Carolina azolla has significant nutritional value including high mineral yields and calories, and moderate protein content. Whether it is used as a quick-fix in a disaster situation or as part of a long-term resilience plan, the study concludes that Carolina azolla holds excellent potential for use as a fast-growing, short-season crop that requires minimal effort to grow and process and could be used to increase food security in a hungry world.

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Common plant could help reduce food insecurity, researchers find

Photo, posted October 8, 2020, courtesy of Dana L. Brown via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Less Phytoplankton In The Gulf Of Maine | Earth Wise

July 20, 2022 By EarthWise Leave a Comment

Phytoplankton, also known as microalgae, are the base of the marine food web and also play a key role in removing carbon dioxide from the air. They are eaten by primary consumers like zooplankton, small fish, and crustaceans.

Phytoplankton, like land plants, absorb carbon dioxide from the atmosphere and use photosynthesis to grow. Then they become a food source for other organisms and ultimately for people who depend upon marine ecosystems. If phytoplankton productivity is disrupted, there can be adverse effects on regional fisheries and the communities that depend on them.

The Gulf of Maine is becoming warmer and saltier, because of ocean currents pushing warm water into the gulf from the Northwest Atlantic. These temperature and salinity changes have led to a significant decrease in the productivity of phytoplankton. According to a new paper from scientists at Bigelow Laboratory of Ocean Sciences in Maine, phytoplankton are about 65% less productive in the gulf than they were 20 years ago.

The study’s results come from the analysis of the Gulf of Maine North Atlantic Time Series, a 23-year sampling program of the temperature, salinity, chemical, biological, and optical measurements of the gulf. The scientists refer to what they describe as a giant windmill effect happening in the North Atlantic, which is changing the circulation of water coming into the Gulf of Maine. In the past, inflows from the North Atlantic brought water from the Labrador Current, which made the gulf cooler and fresher. The new circulation is making the water warmer and saltier.

These changes have significant implications for higher marine species, fisheries, the lobster industry, and other activities in the states that border the Gulf of Maine.

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NASA-funded Study: Gulf of Maine’s Phytoplankton Productivity Down 65%

Photo, posted November 15, 2015, courtesy of Paul VanDerWerf via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Manatees And Pollution | Earth Wise

November 11, 2021 By EarthWise Leave a Comment

Manatees are large, gentle, and curious marine mammals measuring up to 13 feet long and weighing up to 3,300 lbs. There are three living species of manatees: The Amazonian Manatee, the West African Manatee, and the West Indian Manatee, which is commonly found in Florida and the Gulf Coast. Manatees inhabit the shallow, marshy coastal areas and rivers of the Caribbean Sea, the Gulf of Mexico, the Atlantic coast, the Amazon basin, and West Africa.

The West Indian Manatee, which includes the Florida Manatee, is protected under the Endangered Species Act. Today, the range-wide population is estimated to be at least 13,000 manatees, with more than 6,500 in the southeastern United States and Puerto Rico.

In Florida, an uptick in nutrient loading from nonpoint sources is triggering algal blooms in Indian River Lagoon and neighboring areas. These algal blooms have decimated seagrass, manatees’ primary food source.

As a result , manatees have starved to death by the hundreds along Florida’s east coast. The state has recorded 974 manatee deaths in 2021, shattering previous annual all-time highs with still approximately two months to go. Manatees, which need to eat between 100-200 pounds of seagrass daily, are now eating the seagrass roots, which permanently kills the aquatic plants.

Efforts are being made to replant seagrass and to restore clam and oyster beds so that the mollusks can help clean the water. But manatees face a myriad of additional threats, including collisions with boats and ships, temperature changes, disease, and crocodile predation.

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Florida lawmakers hear Fish & Wildlife agency response to manatee death ‘catastrophe’

West Indian manatee

Preliminary 2021 Manatee Mortality Table by County

Photo, posted May 7, 2010, courtesy of Jim Reid/USFWS via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A Hidden Source Of Arctic Carbon | Earth Wise

April 24, 2020 By EarthWise Leave a Comment

Researchers from the University of Texas at Austin, the U.S. Fish and Wildlife Service, and Florida State University have published a paper presenting evidence of significant and previously undetected concentrations and fluxes of dissolved organic matter entering Arctic coastal waters. The source of the organic matter is groundwater flow atop the frozen permafrost. The groundwater moves from land to sea unseen, but the new research reveals that it carries significant concentrations of carbon and other nutrients to Arctic coastal food webs.

Globally, groundwater is important for delivering carbon and other nutrients to oceans, but in the Arctic, where much water is trapped in the permafrost, its role was thought to be minimal. But the new research reveals that groundwater may be contributing an amount of dissolved organic matter to the Alaskan Beaufort Sea that is comparable to what comes from neighboring rivers during the summer.

The researchers found that shallow groundwater flows beneath the surface and picks up new, young organic carbon and nitrogen, but it also mixes with layers of deeper soils and thawing permafrost, picking up and transporting century-to-millennia old organic carbon and nitrogen. This material is unique because it is directly transported to the ocean without seeing or being photodegraded by sunlight and may be valuable as a food source to bacteria and higher organisms that live in Arctic coastal waters.

The study concluded that the supply of leachable organic carbon from groundwater amounts to as much as 70% of the dissolved organic matter that enters the Beaufort Sea from rivers during the summer. The role that groundwater inputs play in Arctic coastal ecosystems will be an area of active research for years to come.

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Hidden Source of Carbon Found at the Arctic Coast

Photo, posted June 14, 2015, courtesy of Eugen Marculesco via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.