return

Saving Florida’s Corals | Earth Wise

September 6, 2023 By EarthWise Leave a Comment

When corals are exposed to extended periods of excess heat, they are subject to bleaching, which occurs when they expel the algae that live within their structure. Bleaching can lead to coral death.

This summer, temperatures in the Florida Keys crossed the bleaching threshold in mid-June and remained above it for extended periods of time. This cumulative heat exposure leads to widespread bleaching and significant die-offs. The last major mass bleaching event in the Florida Keys occurred in 2014 and 2015.

The Coral Restoration Foundation has been receiving reports ranging from partial bleaching to mass coral mortality throughout the keys. Several coral restoration sites in the lower Keys have been totally lost already.

The National Oceanic and Atmospheric Administration and its state agency, university, and non-profit partners have initiated actions to try to save Florida’s corals.

They have halted all restoration-related planting and are evacuating some of their nursery-grown stock to climate-controlled labs. They are considering interventions such as shading coral nurseries or even high-value reef sites. They are also considering feeding nursery and wild corals until the waters cool off enough for algae to return.

Modeling indicates that there is a 70-100% chance that the extreme heat in the North Atlantic will persist through September-October. NOAA and its partners will continue to do what they can to save Florida’s Coral Reef for the marine and human communities that depend on them.

**********

Web Links

NOAA and partners race to rescue remaining Florida corals from historic ocean heat wave

Photo, posted April 19, 2012, courtesy of U.S. Fish and Wildlife Service Southeast Region via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

El Niño Will Likely Return | Earth Wise

June 21, 2023 By EarthWise Leave a Comment

El Niño, a weather phenomenon triggered by warm waters in the eastern Pacific, is likely to return this year, according to the World Meteorological Organization. The Pacific has been in the cooler La Niña phase for the past 3 years, which is unusual, but that appears to be coming to a close. According to the WMO, there is an 80% chance that the Pacific will shift to the El Niño phase before fall.

Record hot years typically coincide with El Niño, which adds to the ongoing warming trend in the climate. There is not yet a clear picture of how strong the forthcoming El Niño event will be or how long it might last, but even a mild El Niño could affect precipitation and temperature patterns around the world.

The hottest year on record, 2016, occurred during a particularly strong El Niño. Experts expect that 2024 is likely to see soaring temperatures again. El Niño generally leads to drier conditions in Australia, Indonesia, and southern Asia, but greater amounts of rainfall in South America, the U.S., and parts of Africa. Despite the presence of a cooling La Niña for the past three years, the last eight years have been the hottest on record.

El Niño and La Niña form an intermittent cycle known as the El Niño Southern Oscillation, or ENSO, that is highly influential in shaping the year-to-year variations in weather conditions around the world. ENSO is a natural phenomenon and scientists are still trying to understand how human-caused climate change might be impacting the behavior and dynamics of the cycle.

**********

Web Links

‘A New Spike’ in Global Temperatures in the Forecast

Photo, posted October 11, 2015, courtesy of Harshil Shah via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Two Lost Lakes Return To California | Earth Wise

May 10, 2023 By EarthWise Leave a Comment

The recent siege of powerful storms in California driven by a series of atmospheric rivers has had a significant effect on the severe drought that has plagued most of the state for many years. Many of the state’s reservoirs are at the highest level they have been for decades. The snowpack in the Sierras is well over 200% of its historical average. Many parts of the state are no longer considered to be in drought conditions, and, in fact, flooding has been a serious problem in some areas. This flooding has had some surprising results.

Two California lakes that drained a century ago have reappeared as a result of floodwaters from the recent storms.

Tulare Lake, in California’s Central Valley used to be fed by rain and snowmelt from the Sierras. A system of dams and canals constructed in the early 20th century to support regional agriculture diverted water away from the lake. It used to be the largest freshwater lake in the West but farmers ultimate planted crops in the dried lakebed.

The atmospheric river events in March inundated that farmland and once again there is water in Tulare Lake.

Owens Lake, on the eastern side of the Sierra Nevada, was long fed by mountain streams. The 1913 construction of the Los Angeles Aqueduct redirected water to that city and desiccated the lake. Floodwaters in March caused a partial collapse of the aqueduct and when the spill gates on the aqueduct were opened to drain the damaged areas, floodwaters poured in and partially refilled the lake.

California has suffered from drought for many years. With its massive snowpack, as the weather warms, the state may face even more flooding.

**********

Web Links

Two Long-Drained California Lakes Refilled by Floodwaters, Satellite Images Show

Photo, posted November 10, 2014, courtesy of CN via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Return Of The Fin Whale | Earth Wise

August 15, 2022 By EarthWise Leave a Comment

The fin whale is the second largest whale species and therefore the second largest creature on Earth. They can grow to more than 80 feet in length. From 1904 to 1976, there was massive industrial whaling in the Southern Ocean surrounding Antarctica. During that period, whalers killed about 700,000 fin whales, reducing their population by 99%. The species was nearly extinct.

In 1982, the International Whaling Commission voted to ban commercial whaling. Since that time, fin whales started to make a comeback in their historical feeding grounds.

During a nine-week expedition in the waters around the Antarctic Peninsula, researchers encountered the largest gathering of fin whales ever documented. About 150 fin whales were seen diving and lunging against the water’s surface. It was a feeding frenzy triggered by large amounts of krill in the water. The actions of the whales are known as a “whale pump” that drives the krill to the surface. Not only does it provide huge amounts of food for the whales but also for other animals, including seabirds and seals.

Forty years after the commercial whaling ban, the number of fin whales has been increasing. Large groups were observed in a 2013 survey. Aerial surveys in 2018 and 2019 recorded 100 groups of fin whales, usually composed of a just a handful of individuals. They did document eight large groups of up to 150 individuals.

Not all species of whales have rebounded so successfully since the whaling ban. The rebound in fin whale population is not only good for the whales, but for the entire ecosystem in the Southern Ocean. It is a glimmer of good news in a time of great challenges for global biodiversity and for marine life in particular.

**********

Web Links

Once Facing Extinction, Massive Fin Whales Have Returned to Antarctic Waters

Photo, posted November 15, 2007, courtesy of Gregory Smith via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Return Of The Blue Whales | Earth Wise

December 21, 2020 By EarthWise Leave a Comment

An international research team has revealed that critically endangered Antarctic blue whales have returned to the sub-Antarctic island of South Georgia, 50 years after whaling just about wiped them out. Other recent research has found that humpback whales are also returning to the region.

Blue whales were commonplace off South Georgia before 20th century industrial whaling taking place between 1904 and 1971 killed over 42,000 of them there. Most of that number were killed before the mid-1930s. As a result, blue whales essentially vanished from the region. Whale survey ships sighted only a single blue whale between 1998 and 2018.

But things have changed in recent years. A survey this past February resulted in 58 blue whale sightings and numerous acoustic detections. Although commercial whaling was banned in the area in the 1960s, it has taken a long time for the whales to make a comeback.

Researchers are not sure why blue whales have taken so long to return to the area. It may be that so many were killed over the years that the remaining population had little or no cultural memory of South Georgia Island as a foraging ground, and that it is only now being rediscovered.

In total, 41 individual blue whales have been photo-identified from South Georgia over the past 10 years, although none of those matched the 517 whales in the current Antarctic blue whale photographic catalogue. Dedicated whale surveys are difficult in a region known for its harsh weather and inaccessibility but are crucial to the future management of South Georgia’s seas. In any case, researchers see the recent sightings as a very positive step forward for conservation of the Antarctic blue whale.

*********

Web Links

Blue whales return to South Georgia after near extinction

Photo, posted September 7, 2007, courtesy of the NOAA Office of National Marine Sanctuaries via Flickr. Photo credit: NOAA.

Earth Wise is a production of WAMC Northeast Public Radio.

The Return Of The Bison

September 28, 2018 By EarthWise Leave a Comment

At one time there were 20 to 30 million bison in North America, dominating the landscape from the Appalachians to the Rockies, and from the Gulf Coast to Alaska. A combination of habitat loss and totally unregulated hunting of the huge animals reduced the population to just over 1,000 in 1889.

The Return Of The Bald Ibis

September 6, 2018 By EarthWise 1 Comment

The northern bald ibis, also known as the waldrapp, is a strange-looking bird with a long, curved beak, a naked head, and feathers that point straight into the air like a Mohawk haircut. In former centuries, it occurred widely in northern and eastern Africa, Asia Minor, Arabia, and parts of Europe. The ancient Egyptians considered it to be an afterworld divinity and its likeness can be seen in hieroglyphs dating back thousands of years.