warming waters

Manatees are not Florida natives

December 20, 2024 By EarthWise Leave a Comment

Florida is very proud of its manatees. It has a county named after them and has pictures of them on license plates. These gentle creatures are part of Florida culture. But recent research indicates that manatees – also known as sea cows – might only be relatively recent residents of the Sunshine State.

Manatees have been spotted in Florida waters for several centuries but might have only been tourists visiting briefly before returning to their home waters in the Caribbean in places like Cuba.

The new research suggests that manatees might not have actually taken up residence in Florida until after Europeans colonized the area in the 1500s. There is a rarity of manatee bones on archaeological sites that date back further. It was particularly striking that Crystal River, which is an epicenter for modern manatee populations, had little evidence of their presence in earlier times.

Even into the early 1900s, Florida newspaper reports treated manatee sightings as a spectacle rather than a common occurrence. In the 1920s and 1930s, there started to be more routine sightings in places like yacht basins and canal harbors. In the 1950s, manatees became more plentiful in Tampa Bay and Crystal River. The warming waters and human activities creating shallow warm water refuges increased manatee populations, particularly near places like power plants.

The current Florida manatee population is between 8,000 and 12,000 and is classified as threatened under the Endangered Species Act, an improvement over its previous endangered status. But pollution is killing a lot of the seagrass that they eat, and their safety is by no means assured.

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Why manatees are likely not Florida natives

Photo, posted March 25, 2012, courtesy of David Hinkel / USFWS via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Helping Corals With Beneficial Bacteria | Earth Wise

March 31, 2021 By EarthWise Leave a Comment

A group of researchers at the King Abdullah University of Science and Technology in Saudi Arabia is exploring a novel technology to improve the health of corals. Around the globe, corals are being stressed by pathogens, toxins, and warming waters leading to widespread bleaching events.

The new idea is to introduce beneficial bacteria to the corals, thereby boosting the strength and resilience of their symbiotic partners. The concept is akin to the use of probiotics in plant science. Corals rely on bacterial and algal symbionts to provide nutrients, energy (through photosynthesis), toxin regulation, and protection against pathogens.

The researchers selected bacteria that are naturally symbiotic to specific coral species on reefs in the Red Sea, ensuring that no alien bacteria are accidentally introduced. A probiotic cocktail comprising six bacteria strains was used in a laboratory setting. Results in the lab have been promising so far, as they have observed dynamic and metabolic alterations to the corals that boosted their chances of survival under heat stress.

Success in the lab will need to be translated to success in the open oceans, which is challenging. Scaling up and seeding whole reefs might involve robots and artificial intelligence in order to deliver probiotics either into sediments or directly onto corals.

The use of beneficial microorganisms is not the solution to the global destruction of coral reefs. Only worldwide CO₂ mitigation can ultimately accomplish that. But the probiotic approach might buy corals some time as they deal with shifting environmental pressures and try to adapt to a changing world.

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Microbiome boost may help corals resist bleaching

Photo, posted March 18, 2018, courtesy of Steven dos Remedios via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Giant Jellyfish | Earth Wise

August 28, 2020 By EarthWise Leave a Comment

There have been recent news stories about giant jellyfish washing ashore from Maine to the south coast of Massachusetts. These stories have claimed that some of these lion’s mane jellyfish have been the largest on record and even might be the largest animals in the ocean.

The truth of these accounts is rather suspect. For one thing, it is rather difficult to measure the size of a jellyfish when it is out of the water. Gravity compresses and spreads out the bell portion of the animal, and that makes up the bulk of its mass. For example, a jellyfish bell that measures four feet across on the beach would appear to be much smaller if the animal was floating in the water.

Some claims that lion’s mane jellyfish are larger than blue whales date back a full century and are very much disputable. The claimed size certainly included the animal’s long tentacles, and such things hardly compare with a blue whale.

In any event, the current spate of jellyfish sightings is not necessarily that unusual. Many factors influence jellyfish populations, including water temperature and food supply. It is possible that warming water temperatures may be influencing the jellyfish population this year, but there is not enough data to know for sure.

People do need to be cautious around lion’s mane jellyfish. They do sting and while their stings are not as bad as those of a number of other species, they can be a problem for people who have allergic reactions. Furthermore, the stinging cells remain active in a jellyfish that has washed ashore.

Sightings of these animals are continuing, and reports of larger specimens continue as well, even if they don’t compare with blue whales.

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Jellyfish larger than blue whales?

Photo, posted September 13, 2015, courtesy Derek Keats via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

More Antarctic Warming

April 23, 2019 By EarthWise Leave a Comment

East Antarctica is the coldest place on Earth. It makes up two-thirds of the continent, is home to the South Pole, and has vast ice sheets that have been around for tens of millions of years and are nearly three miles thick in places. Temperatures there hover around 67 degrees below zero. In 2010, a few spots on East Antarctica’s polar plateau reached a record-breaking 144 degrees below zero.

But almost unbelievably, parts of the East Antarctic seem to be melting.

Scientists are seeing worrying signs of ice loss in the East Antarctic. Glaciers are starting to move more quickly and are dumping their ice into the Southern Ocean. Satellite images show the fast-moving ice. The biggest glacier – the Totten Glacier – alone contains enough ice to raise global sea levels by over 12 feet.

The Antarctic as a whole contains about 90% of the planet’s ice. In theory, if it all melted, it would raise global sea levels by an average of 200 feet.

The growing concerns about eastern Antarctica are not that its interior plateau will soon start to melt. It is still extremely cold there and should stay that way for a long time. But its edges, which are in contact with warming ocean waters, are the real worry. As the region’s ice shelves, which float atop the Southern Ocean, erode, the vast glaciers behind them could rapidly accelerate their slide into the sea.

Today, satellites show huge glaciers moving rapidly toward the coast, with wide rivers of ice sometimes moving several miles a year. In the face of rapid change and limited data, it is difficult to predict what the Antarctic will do in the future. But it doesn’t look good.

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Polar Warning: Even Antarctica’s Coldest Region Is Starting to Melt

Photo, posted January 3, 2013, courtesy of Christopher Michel via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Protection From Toxic Algae

March 28, 2019 By EarthWise Leave a Comment

Toxic algal blooms have been a growing problem in recent years associated with warming waters and nutrient-rich agricultural runoff in lakes, rivers, and oceans. In 2014, an algal bloom in Lake Erie left half a million residents of Toledo, Ohio without safe drinking water for three days.

The most common toxic substance released by algal blooms in the lake is called microcystin, which is closely linked to liver cancer and other diseases. Toxicologists measure microcystin and other contaminants using the metric of parts per billion. The EPA recommends that young children not drink water containing more than 0.3 parts per billion and adults no more than 1.6 parts per billion of microcystin.

Scientists at the University of Toledo have been working on developing a biofilter that uses naturally occurring Lake Erie bacteria to remove microcystin released by algal blooms and thereby reduce or eliminate the use of chlorine and other chemicals.

They have successfully isolated a number of types of bacteria that degrade microcystin toxin at a daily rate of up to 19 parts per billion. To their knowledge, such bacteria have not been previously used to fight algal blooms in other parts of the world. Based on the recorded toxin levels in Lake Erie in recent years, the bacteria would be able to effectively remove microcystin from water supplies. None of the 13 bacterial isolates they found have any association with human disease so their use in future water-purifying biofilters should not pose a public health concern.

The researchers are now developing and testing biofilters, which are water filters containing the specialized bacteria that will degrade the toxins from lake water as it flows through the filter.

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Scientists advance new technology to protect drinking water from Lake Erie algal toxins

Photo, posted April 30, 2014, courtesy of NOAA via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Climate Change And Lobster

September 2, 2015 By EarthWise

It’s no secret that ocean waters are warming, especially in New England. The waters in the Gulf of Maine are warming 99% faster than the rest of the world’s oceans. What’s the problem? Well, lobsters like cold water, and as a result, they’re heading north.