tolerant

Attack of the giant goldfish

January 15, 2024 By EarthWise Leave a Comment

Goldfish are just about the easiest pets to keep. A species of carp native to East Asia, they have been bred to look pretty and are generally little more than home décor. We keep them in little glass bowls and feed them mysterious flakes out of a container. With these confined quarters and meager meals, they remain small, harmless creatures. But released into the wild, it is a very different story.

People dump pet goldfish into lakes and ponds with some frequency. Once they are in the wild, these humble creatures can grow to monstrous proportions. They can eat nearly anything, including algae, aquatic plants, eggs, and invertebrates. They can kill off native marine wildlife and damage or even destroy fragile and economically valuable ecosystems.

For a few years, Canadian researchers have been tracking invasive goldfish in Hamilton Harbour, at the western tip of Lake Ontario, about 35 miles southwest of Toronto. That part of the lake has been decimated by industrial and urban development as well as by invasive species.

Goldfish were first spotted in the harbor in the 1960s, mostly died off in the 70s because of industrial contamination, but then recovered in the 2000s. Goldfish can tolerate a wide range of water temperatures, reach sexual maturity quickly, and can reproduce several times in one season. In resource-rich places, they can grow up to 16 inches long, making them too large a meal for many predators.

There are literally millions of goldfish in the Great Lakes and not only there. Feral goldfish are a problem in Australia and in the United Kingdom. Invasive species are a big problem, even if they start out small and cute.

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Once They Were Pets. Now Giant Goldfish Are Menacing the Great Lakes.

Photo, posted September 20, 2015, courtesy of Watts via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Tepary Beans | Earth Wise

September 2, 2022 By EarthWise Leave a Comment

Tepary beans are an ancient crop native to the northern part of Mexico and the southwestern part of the U.S.. They have been grown in those places by native peoples since pre-Columbian times. They are still grown in Native American reservations in Arizona’s Sonoran Desert. One can purchase them from some small farms in that region.

What sets tepary beans apart from other beans is that they are among the most drought- and heat-tolerant legume crops in the world. They can be grown without irrigation under conditions that are not viable for other crops. They can be consumed by people like many other kinds of beans, and they can also provide forage for livestock with better nutrition content than many other plants. They seem to be a very attractive option for a crop in the changing climate. What is lacking, at present, is large supplies of tepary seeds to be planted.

Researchers at Texas A&M have been funded to bring tepary beans into modern cropping systems and diets. The goal is to develop tepary bean cultivars with high biomass and yield that are still well-suited to drought and heat conditions. Getting the beans to the point of widespread commercialization will take several years. The end result should be of interest to pulse growers, seed industries, and food companies across the U.S.

Tepary beans are higher in fiber and protein than most other beans. They come in several different colors, each of which has unique flavor and texture characteristics. The white ones have a naturally sweet flavor. The brown beans are slightly nutty in flavor and are similar to pinto beans. If the Texas program is successful, we may all be eating tepary beans some day.

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Tepary Beans Offer Producers A Low-Input, Climate-Resilient Legume Alternative

Photo, posted August 25, 2017, courtesy of Katja Schulz via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Prickly Pear As A Sustainable Crop | Earth Wise

April 6, 2021 By EarthWise Leave a Comment

The fruits and pads of opuntia, better known as prickly pear cactus, find their way into people’s diets in many arid and semi-arid places around the world. In Mexico, the pads are known as nopales and are used in a variety of dishes. The pears themselves are used in jams, salads, and juices.

A five-year study by the University of Nevada Reno College of Agriculture, Biotechnology & Natural Resources investigated the prospects for cactus pear to become a major crop like soybeans and corn and to help provide a biofuel source.

As the climate changes, dry areas are going to get dryer and drought issues will increasingly affect traditional crops.

The study looked at the particular opuntia species called the spineless cactus pear and found that it had the highest fruit production while using up to 80% less water than some traditional crops. Cactus pear can be used for both human consumption and livestock feed. As a perennial crop, once the fruit and pads are harvested for food, the remaining biomass can be used for biofuel production.

Corn and sugar cane are the most utilized bioenergy crops right now, but these use three to six times more water than cactus pear. The cactus pear productivity is on par with corn and sugar cane, but not only do they use a fraction of the water, they also have higher heat tolerance.

Over 40% of land area around the world is classified as semi-arid or arid. There is enormous potential for planting cactus for carbon sequestration. If nothing else, it makes great sense to grow cactus pear crops in abandoned areas that are marginal and may not be suitable for other crops.

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Study shows cactus pear as drought-tolerant crop for sustainable fuel and food

Photo, posted April 16, 2020, courtesy of Kevin Dooley via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Heat-Resistant Coral | Earth Wise

June 23, 2020 By EarthWise Leave a Comment

Coral reefs are in decline all over the world. Corals are under increasing pressure as water temperatures rise and the frequency and severity of coral bleaching events increase. Nowhere is this more evident than in Australia’s Great Barrier Reef system, where severe bleaching events have happened in three of the past five years. Long-term prospects for the survival of the world’s largest reef system are now considered to be poor.

A team of scientists at Australia’s national science agency – the Commonwealth Scientific and Industrial Research Organization – along with the Australian Institute of Marine Science and the University of Melbourne have successfully produced in a laboratory setting a coral that is more resistant to increased seawater temperatures.

The team made the coral more tolerant to temperature-induced bleaching by bolstering the heat tolerance of the microalgae symbionts that live inside the coral tissue. They isolated the microalgae from coral and cultured it in the laboratory using a technique called “directed evolution”. Over the course of four years, they exposed the microalgae to increasingly warmer temperatures. When the heat-adapted strain of algae was reintroduced into coral larvae, the newly established coral-algal symbiosis was more heat tolerant than the original one. The heat-tolerant microalgae are better at photosynthesis and improve the heat response of the coral animal.

The next step is to further test the algal strains in adult colonies across a range of coral species. This groundbreaking research provides a promising and novel tool to increase the heat tolerance of corals and might potentially lead to a way to save the Great Barrier Reef as the world continues to warm.

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Scientists successfully develop heat resistant coral to fight bleaching

Photo, posted September 22, 2010, courtesy of NOAA via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Wildlife Corridors

December 28, 2016 By EarthWise

It is widely thought that we are in the midst of the 6th great mass extinction of species on Earth and, unlike the previous ones that were caused by things like asteroid impacts or ice ages, this one is caused by us. Our impact on the climate, on natural resources, on landscapes and habitats, and more, has wreaked havoc on ecosystems across the globe.

[Read more…] about Wildlife Corridors