Articles from August 2024

Wetlands can cool city air by 4.7 degrees Celsius during heatwaves, according to the most comprehensive review of its kind. In a list of various city features, such waterways ranked second for their cooling abilities.

Water is the driving force of all nature. And it seems to take on an added significance in summer when heatwaves roll across the nation. Water cools us and sustains us, but we are abusing it.

Water in the form of wetlands can cool city air by almost 5 degrees Celsius during heatwaves, according to a new review and the most comprehensive of its kind. But a recent analysis shows that human pressures—such as dam construction, global warming and large-scale irrigation—have altered freshwater resources to such an extent that their capacity to regulate vital climatic and ecological processes is at risk.

One of the first steps we can take to better safeguard our waters is to make sure that they have legal rights and that they are not being violated. Luckily, machine learning can now be used to more accurately predict which wetlands and waterways are protected by the Clean Water Act of 1972. Unfortunately, though, a recent analysis found that a 2020 Trump administration rule removed Clean Water Act protection for one-fourth of U.S. wetlands and one-fifth of U.S. streams, and it also deregulated 30% of watersheds that supply drinking water to household taps.

Hopefully, a better understanding of freshwater dynamics will help guide the creation of new policies to help mitigate the harms we’ve caused to our waterways and wetlands.

As an urban cooling agent, botanical gardens ranked first, causing temperatures to be 5 degrees Celsius cooler than they would be without the gardens.

Cooling cities during heatwaves: botanical gardens, parks and wetlands

In February 2024, researchers from the University of Surrey Global Center for Clean Air Research in Guildford, England, looked at green spaces and waterways in cities and towns and analyzed if having such features cooled the air.

Among the key findings of the analysis, which was published in the journal The Innovation, were the following landscape features and how much each of them lowered the surrounding temperatures:

• Botanical gardens: -5 C average (variation: -2.2 C to -10 C)
• Wetlands: -4.7 C average (variation: -1.2 C to -12 C)
• Rain gardens: -4.5 C average (variation: -1.3 C to -7 C)
• Green walls: -4.1 C average (variation: -0.1 C to -18 C)
• Street trees: -3.8 C average (variation: -0.5 C to -12 C)
• City farms: -3.5 C average (variation: -3 C to -3.9 C)
• Parks: -3.2 C average (variation: -0.8 C to -10 C)
• Reservoirs: -2.9 C average (variation: -1.8 C to 5 C)
• Playgrounds: -2.9 C average (variation: -2.8 C to -3 C)

For the past century, humans have been pushing the Earth’s freshwater system far beyond the stable conditions that prevailed before industrialization. Exceptional conditions are now much more frequent and widespread than before.

While it has been known for some time that green spaces and water can cool down cities, this study provides the most comprehensive picture yet. What’s more, it explains why: from trees providing shade to evaporating water cooling the air.

The scientists say they hope their work will help city and town planners around the world confront the challenges of global heating.

Relieving pressure on freshwater systems: returning them to a stable state

It’s clear that wetlands and waterways are becoming more and more important as the Earth continues to warm. Sadly, however, they are in trouble.

Human pressures, such as dam construction, have altered freshwater resources to such an extent that their capacity to regulate essential ecological processes is no longer guaranteed.

In a study that was published in the science journal Nature Water in March 2024, scientists state that human activity has pushed variation in the planet’s freshwater cycle well outside of its preindustrial range, and its capacity to regulate vital climatic and ecological processes is no longer assured.

This is the first time that the global water cycle change has been assessed over such a long timescale with an appropriate reference baseline. Using data from hydrological models that combine all major human impacts on the freshwater cycle, an international research team calculated monthly streamflow and soil moisture at a spatial resolution of roughly 31 by 31 miles. As a baseline, they determined the conditions during the preindustrial period (1661–1860). They then compared the industrial period (1861–2005) against this baseline. Their analysis revealed an increase in the frequency of exceptionally dry or wet conditions, with deviations in soil moisture and streamflow.

Dry and wet deviations have consistently occurred over substantially larger areas since the early 20th century than during the preindustrial period. Overall, the global land area experiencing deviations has nearly doubled compared with preindustrial conditions.

In many regions with a long history of human occupation and agriculture, such as along the Nile River, irrigation has caused exceptionally dry streamflows and wet soil-moisture conditions.

Exceptionally dry streamflow and soil-moisture conditions became more frequent in many tropical and subtropical regions, while many boreal and temperate regions saw an increase in exceptionally wet conditions, especially in terms of soil moisture. These patterns match changes seen in water availability due to climate change.

There were more complex patterns in many regions with a long history of human agriculture and land use. For example, the Indus, Mississippi and Nile River Basins have experienced exceptionally dry streamflow and wet soil-moisture conditions, indicating changes driven by irrigation.

With this comprehensive view of the changes in soil moisture and streamflow, researchers are better equipped to investigate the causes and consequences of the changes in the freshwater cycle. Understanding these dynamics in greater detail could help guide policies to mitigate the resulting harm, although the immediate priority is decreasing human-driven pressures on freshwater systems, which are vital to life on Earth, conclude the researchers.

The 1972 Clean Water Act protects the “waters of the United States,” but it does not precisely define which streams and wetlands this phrase covers, leaving it to courts, presidential administrations and regulators to decide.

Predicting coverage of the Clean Water Act: deregulating drinking water, streams and wetlands

Just when we need to augment, protect and value our wetlands and waters, we are doing the opposite, concludes a recent study led by a team at the University of California, Berkeley.

The 1972 Clean Water Act protects the “waters of the United States,” but it does not precisely define which streams and wetlands this phrase covers, leaving it to courts, presidential administrations and regulators to decide. As a result, the exact coverage of Clean Water Act rules is difficult to estimate. So, the University of California, Berkeley, team used machine learning to more accurately predict which waterways are protected by the act.

The machine-learning model predicted regulation across the U.S. under a 2020 Trump administration rule and its predecessor, the Supreme Court’s Rapanos ruling, which had previously guided decisions. It was found that the 2020 Trump administration rule removed Clean Water Act protections from one-fourth of U.S. wetlands and one-fifth of U.S. streams—690,000 stream miles, more than every stream in California, Florida, Illinois, New York, Ohio, Pennsylvania and Texas combined—and it deregulated 30% of watersheds that supply drinking water to household taps. The wetlands deregulated under the 2020 rule provided more than $250 billion in flood prevention benefits to nearby buildings, say the study’s authors.

A 2020 rule deregulated 690,000 stream miles, more than every stream in California, Florida, Illinois, New York, Ohio, Pennsylvania and Texas combined.

Prior analyses assumed that streams and wetlands sharing certain geophysical characteristics were regulated, without scrutinizing data on what was truly regulated, an approach the Environmental Protection Agency and the U.S. Army Corps of Engineers called “highly unreliable.”

It’s believed that the machine-learning model’s predictions could save more than $1 billion annually in permitting costs for developers and regulators by providing immediate calculations of the probability that a site is regulated, rather than waiting months through the uncertain process for obtaining permits.

In 2023, a President Biden White House rule expanded the Clean Water Act’s jurisdiction. The Supreme Court’s 2023 Sackett decision then contracted it. Once Sackett is fully implemented, this machine-learning methodology can clarify its scope.

Unaltered waterways support biodiversity, help control floods and provide clean drinking water. Rivers, such as the Colorado, are also vital to our food supply. The Colorado River irrigates almost 90% of our nation’s winter vegetable crops. We need to take our waters far more seriously.

Valuing water: wells and their worth

This recent game of regulatory ping-pong certainly has had staggering effects on environmental protections. In this era of ever-lengthening heatwaves, we need to take our cooling waters far more seriously.

In his very folksy way, Benjamin Franklin once said, “When the well is dry, we’ll know the worth of water.”

That “well”—whether it’s situated in our neighborhoods or on a global level—may be very close to parched.

Here’s to finding your true places and natural habitats,

Candy

The post Water, Wetlands and Wells first appeared on Good Nature Travel Blog.

According to World Wildlife Fund, the huge, frozen landmass at the bottom of our planet is more than just spectacular icing on the globe. It could be vital for our survival, too. Antarctic ice deflects some of the sun’s rays away from the Earth, keeping temperatures livable.

American environmentalist, historian and novelist Wallace Stegner called our national parks “the best idea we ever had.” In 1983, he wrote: “National parks are … absolutely American, absolutely democratic, they reflect us at our best rather than our worst.”

I wholeheartedly agree, but I think there’s another stellar notion that stands alongside that one for reminding us of the importance of conserving and protecting precious and unique places. And this one’s not only on the national level but, on the global one, as well: the Antarctic Treaty.

The Antarctic Treaty was signed on December 1, 1959. It set aside Antarctica—which represents 10% of the planet— “forever to be used exclusively for peaceful purposes and shall not become the scene or object of international discord.”

The treaty recognizes the White Continent as a preserve for peace and scientific study, and it went into effect with 12 original signatories: Argentina, Australia, Belgium, Chile, France, Japan, New Zealand, Norway, South Africa, the United Kingdom, the United States and the U.S.S.R. Today, more than 50 nations recognize the treaty. It is the foundation upon which decades of scientific achievements and advancements rest.

The ocean surrounding the Antarctic continent supports masses of sea life, including five species of dolphins, five species of penguins, nine species of whales and six species of seals. The nutrient-rich waters encourage blooms of tiny plankton, the basis of the ocean food chain.

Nature travelers also flock to Antarctica. But are all those tourists—about 74,000 prepandemic, far more than the annual number of scientific staff—going there to appreciate, learn about and become ambassadors for the White Continent? Or is there another, more compelling reason?

In answer to that question, researchers think they’ve found a new trend—and it may not be what you’d expect.

(function(d,u,ac){var s=d.createElement(‘script’);s.type=’text/javascript’;s.src=’https://a.omappapi.com/app/js/api.min.js’;s.async=true;s.dataset.user=u;s.dataset.campaign=ac;d.getElementsByTagName(‘head’)[0].appendChild(s);})(document,123366,’cklysp4prnt2xgd9n1kg’);

The beginnings of Antarctica Day

Among its many groundbreaking provisions, the Antarctic Treaty froze territorial claims to the continent, banned nuclear weapons and waste there, and preserved the entire region south of 60 degrees latitude for peaceful purposes. The prohibition of military activities makes it effectively the first nuclear-arms-control agreement in history.

Scientific research conducted in Antarctica has three goals: (1) to understand the region and its ecosystems, (2) to understand Antarctica’s effects on and responses to global processes, such as climate change, and (3) to use the region as a platform to study the upper atmosphere and space.

For those reasons and more, the Antarctic Treaty is worthy of celebration and honor. Antarctica Day was established by the Foundation for Good Governance of International Spaces in 2010 to commemorate the continuation of the treaty. Along with Midwinter Day—an annual jubilee held on the day of the southern winter solstice (June 20 or 21)—Antarctica Day is one of the continent’s two principal holidays. It is a celebration for personnel overwintering at Antarctic research stations, although some people off the continent observe it, as well.

The importance of climate research

For the United States, the National Science Foundation (NSF) provides the oversight for scientific endeavors in the region, including logistical and programmatic support to thousands of scientists who travel to the continent each year to conduct research in fields ranging from astronomy to meteorology to paleontology. Some of the most important work there involves climate change studies.

Scientists say that Antarctica is ground zero for understanding global climate change and its effects on society. The continent, its ice sheets and surrounding oceans play a crucial role in the distribution of heat over our planet and the extent of sea-level rise. They also show how Earth-system processes affect the marine resources that humans depend on.

Antarctica has a profound effect on the Earth’s climate and ocean systems. Locked in its two-and-a-half-mile-thick ice sheet is a unique record of what our planet’s climate was like over the past 1 million years.

For example, over the past 30 years, the amount of ice flowing out of Antarctica’s Thwaites Glacier has nearly doubled. Warm ocean water from the Amundsen Sea circulates under the ice, creating melt, which loosens the ice from the bedrock below. This hastens flow and glacial retreat and contributes to rising sea levels.

The International Thwaites Glacier Collaboration, supported jointly by the United States Antarctic Program and the British Antarctic Survey, is exploring marine sediments and the ocean, measuring currents flowing toward the deep ice and examining the bending, grinding and stretching of the glacier over the landscape below. The stakes here are worldwide: should the Thwaites Glacier collapse, the ice released could raise sea levels by as much as 11 feet. Scientists are still trying to determine how long this will take: centuries or just decades.

Another aspect of climate change studied in Antarctica by NSF researchers is the impact of warming temperatures on Antarctic ecosystems. Over the last two decades, demographic studies of Adelie penguins in the Ross Sea explored several potential mechanisms for the birds’ population changes. This research is helping us to better understand population dynamics and how penguin colonies might respond to future environmental changes.

In a recent study, people in the “social bonding” group didn’t mention anything about seeing wildlife as a principal reason for traveling to Antarctica. Rather, the place was chosen as a backdrop for a special occasion.

In the Antarctic Peninsula region, which is experiencing the most rapid climate warming on the planet, scientists involved in the Palmer Station Long-Term Ecological Research Study are determining how the rapid reduction of sea ice is affecting all levels of the food chain. Studies include many organisms in the food web, including bacteria, krill, penguins, phytoplankton, marine mammals, seabirds, viruses and zooplankton.

Antarctic researchers are literally at the tip of the iceberg, exploring new frontiers and seeking answers to some of the planet’s most important questions. None of this would be possible without the Antarctic Treaty.

The reasons for Antarctica travels

Some people travel to Antarctica for the experience and for learning, many go to fulfill a lifelong dream, others visit for the adventure, and there are those who go to socialize—such as to mark an anniversary, go on a honeymoon or to spend time with family for a holiday. It’s the social bonding group’s motivations that researchers find particularly interesting: people in that group didn’t mention anything about seeing penguins or other wildlife as the principal stimulus; rather, Antarctica was chosen as a backdrop for a celebration or event.

While Antarctic tourists are purported to have meaningful interactions with the unique environment, not much is known about how the journey shapes their later pro-environmental behaviors.

The researchers, whose findings were published in the Journal of Outdoor Recreation and Tourism in March 2022, launched their prepandemic study on tourism to Antarctica because travel to the continent has diversified and grown. In the 2019–2020 tourist season, more than 74,000 travelers went to Antarctica, which is double the number of tourists seen five years prior. While tourism can be a tool to inspire people to become ambassadors for the conservation of Antarctica—a fragile ecosystem facing crumbling glaciers, invasive species and wildlife diseases—it also can create challenges.

During the last two decades, a lot of new, different activities have been introduced to Antarctica, and there are also novel ways of traveling there. This is diversifying how you can access Antarctica—and the profiles of the tourists who visit.

To understand these new tourists’ motivations, researchers surveyed people before and after they traveled by airplane or ship to Antarctica during the 2019–2020 season. They found four main reasons tourists gave for traveling there: experience and learning (31%), social bonding (28%), adventure (23%) or to take a trip of a lifetime (17.5%).

Tourism in Antarctica has been diversifying and growing. During the past 20 years, a lot of new activities have been introduced, and there are novel ways of traveling there, including by sailboat.

Many in the “social bonding” and “trip of a lifetime” groups saw Antarctica as a last-chance destination; a finding that researchers have also documented with other sites endangered by climate change, such as the Great Barrier Reef and the Arctic.

Now that we have more people traveling to Antarctica for social bonding, communicating with these tourists may require different strategies than those used in the past. For example, this kind of tourist may not want to attend lectures, and tour providers will have to better deliver conservation messages so that any changes they hope to make in people’s environmental concerns or behaviors will last in the long term.

When the scientists analyzed whether tourists in the various groups were more or less likely to have learned something from the trip—or perceived that they had learned something—they found that tourists in the “trip of a lifetime” group were more likely to have higher perceptions of learning. Tourists in the “experience and learning” group had the highest overall average score for actual learning.

Tourists who go to Antarctica primarily for social bonding reasons may not want to attend lectures. Tour providers will have to deliver conservation and environmental messages in new ways. ©Colby J. Brokvist

Surprisingly, the researchers also found there was a relationship between tourists’ perceptions of how much they learned about Antarctica and its ecosystem and their intentions to change their environmental behaviors. If they felt they got something from the learning experience, then they were more likely to change what they did after the trip. That has important implications for communicators, educators and tour operators and suggests that perception means a lot to people; it’s part of the experience.

The researchers say they want to study actual behavioral changes in future work, as well as look at Antarctic tourism after the pandemic closures and slowdowns. COVID may have caused people to see the world a little bit differently, they postulate.

The wisdom of those who have been there

“You can’t protect what you don’t know,” Lars-Eric Lindblad, leader of the first commercial Antarctica cruise in 1966, once said. And “we should have the sense to leave just one place alone,” stated Sir Peter Scott, founder of World Wildlife Fund and son of Antarctic explorer Robert Falcon Scott.

I think the reality—and the idea—of Antarctica reflects us at our best.

There is a lot of wisdom in both these quotes. Sir Peter Scott is right; there are certainly environmental implications of tourism to Antarctica. But, as Lars-Eric Lindblad implied, if done responsibly, visiting Antarctica can teach people a lot about this unique continent’s environment.

I, however, keep going back to the thoughts of Wallace Stegner. I think that, more than anything, Antarctica reflects us at our best rather than our worst.

Here’s to finding your true places and natural habitats,

Candy

Explore the White Continent on one of our Antarctica Sailing expeditions!

The post The New, Surprising Reasons Travelers Visit Antarctica first appeared on Good Nature Travel Blog.

It was the early evening when we spotted our first jaguar, a male named Timbó, who was lounging in the tall grass of Brazil’s Pantanal, waiting for night to fall. We watched him closely from the safety of our safari transport, a vehicle that Timbó hardly noticed. This was thanks to the ongoing efforts of Onçafari. This conservation initiative aims to promote ecotourism and wildlife watching within several Brazilian biomes, and in the case of jaguars—transforming the image of this keystone species from one that people might hunt for profit into a source of sustainable tourism and income. By the time our safari was through, we’d spotted six jaguars in less than three days. I’d say their efforts are working. 

© Helder Brandāo de Oliveira (Nat Hab Expedition Leader)

A new study published in the journal Science this April shows just how successful conservation efforts can be when it comes to protecting and maintaining biodiversity. In this first-of-its-kind meta-analysis to see the effects of conservation action overall, scientists from research institutes around the globe reviewed 655 implemented conservation measures that spanned more than a century and target different levels of biodiversity, including a variety of species, ecosystems, and genetics. After evaluating the changes to biodiversity that these measures have led to, compared to what would have happened without them, the results show that in two out of every three cases, the results were positive. At the very least, they slowed declines in biodiversity. 

 “This new analysis is the best evidence to date that conservation interventions make a difference, slowing the loss of species’ populations and habitats and enabling them to recover,” says Stuart Butchart, the study’s co-author and chief scientist at BirdLife International, protecting avian species worldwide. “It provides strong support for scaling up investments in nature to meet the commitments countries have signed up to.”

Butchart is likely referring in part to the United Nations Biodiversity Conference, a nearly two-week gathering of governments from around the globe in Montreal in December 2022. Here, nations are committed to several new global goals and targets that will be achieved by 2030. These include protecting 30% of the planet’s lands, inland waters, coastal areas and oceans, emphasizing areas of particular importance ecosystem functioning and services, as well as biodiversity—which the U.N. calls “our strongest natural defense against climate change.” 

Baobob trees of Madagascar

How Biodiversity Loss Affects Us 

Biodiversity supports healthy ecosystems, including everything from clean air and fresh water to the pollination of crops. In turn, healthy ecosystems reduce the effects of climate change by acting as natural carbon sinks and both absorbing and storing carbon dioxide (CO2) from the atmosphere. Such ecosystems also allow species and organisms to work together to build strength, support life, and thrive. 

Declines in biodiversity also threaten wildlife. According to the International Union for Conservation of Nature’s Red List of Threatened Species, more than 44,000 species are at risk of becoming extinct, including critically endangered wildlife like the orangutans viewable on Nat Hab’s Wilds of Borneo Adventure and African forest elephants that live in the Congo and West Africa. The loss of such species would have a ripple effect, not only changing the dynamics among area wildlife but disturbing everything from the stability of an ecosystem to the livelihood of the people who depend on it. 

Orangutans, Borneo © Brad Josephs (Nat Hab Expedition Leader)

Some Success Stories

A few things that have been working to improve the state of biodiversity include establishing and managing protected areas, eradicating invasive species, and restoring habitats while sustainably managing ecosystems. 

According to the study, the ongoing idea is to up the ante on such conservation interventions, which would go a long way toward stopping—as well as reversing—biodiversity loss. Some concrete examples of successful conservation efforts include Central Africa’s Congo Basin, home to some of the largest tropical rainforests on Earth. Here, deforestation was 74% lower in lands set aside for logging operations under a Forest Management Plan (FMP), which promotes sustainable timber extraction practices, compared with concessions without an FMP. Another is central Idaho’s Salmon River basin, where the captive breeding and release of Chinook salmon boosted the natural population of the basin’s fish exponentially with minimal negative impacts on its wild population. 

Grizzly bear fishing for salmon, Katmai National Park, Alaska

When conservation efforts work, they can really do a lot of good. In July 2023, Nat Hab even rounded up some of the most amazing conservation wins worldwide to showcase this very point. One is the more-than-doubling of wild tiger populations in India that’s occurred since 2010 (up from 1,411 to 3,167), thanks to rigorous conservation efforts from the country’s central and state governments, support from scientific institutions and NGOs and the involvement of local communities. Another is Australia’s practicing of effective conservation strategies, including policy changes and enhanced management of fishing vessels, which have led to the elimination of gill nets (walls of netting that can entail and harm, or even kill, marine mammals like bottlenose dolphins and sea turtles) in the Great Barrier Reef. 

Although conservation efforts aren’t always successful, those implementing the programs have been able to learn from their experiences and refine their methods accordingly. There are even cases in which an effort might prove unsuccessful for the species it was targeting but unintentionally beneficial for another form of life instead. For instance, while the population of seahorses in protected sites is lower than in non-protected areas, the number of seahorse predators—including octopus—has become much higher. 

Aerial view of river and ocean meeting in Australia

What Does This All Mean?

In essence, “Conservation matters!” says Gernot Segelbacher, co-author of the study and professor and co-chair of the Conservation Genetic Specialist Group (part of the larger International Union for Conservation of Nature). “While we so often hear about species declining or going extinct, this study shows that we can make a difference.”

Some methods of doing so include continuing to invest in nature in sustainable ways, such as focusing on the long-term benefits for people, nature, and the local economies rather than making short-term, financially based decisions. 

Another is in funding the effective management of protected areas, which safeguard critical habitats for species. 

Of course, conservation through exploration, the Nat Hab ethos, is another way of keeping biodiversity in check. Conservation travel not only showcases the value of natural habitats and the wildlife that thrives there, but it also brings economic resources to local communities and encourages them to protect the wilderness around them. 

The post New Study Shows the Positive Impacts Conservation has on Biodiversity first appeared on Good Nature Travel Blog.

Found in cold waters along a quarter of the world’s coasts, kelp forests are the foundations of many marine ecosystems. They also absorb enormous amounts of pollution, help sequester planet-warming gases and underpin coastal fisheries and the seafood industry—benefits valued at $500 billion a year.

Found along 25% to 30% of the world’s coastlines, kelp forests are the most extensive marine vegetated ecosystems in the world. A type of seaweed, kelp attaches to rocky surfaces on the ocean floor and—like terrestrial plants and trees—grows upward toward the sunlight. Some experts even call kelp “the sequoias of the sea.” It’s an appropriate epithet: stems of bull kelp can soar more than 100 feet high, and their canopies—the frond-like blades that tangle on the ocean surface—are visible from space.

Kelp forests harbor a greater variety and higher diversity of animals and plants than almost any other ocean community. Many organisms use the thick blades to shelter their young from predators or even rough storms. Underwater towers of kelp provide food and habitat for all kinds of marine life, including birds, crustaceans and other invertebrates, fish, sea lions, sea otters, seals, whales and several commercially important fishery species, such as kelp bass and black rockfish.

Unfortunately, however, today kelp forests face a variety of threats, such as commercial kelp harvesting, pollution and climate change, which exacerbates El Nino Southern Oscillation events and negatively impacts kelp reproduction and survival. Overgrazing by fish and sea urchins is a particularly large problem for kelp forests. Predators such as sea otters and sea stars typically keep populations of urchins and grazing fishes in check, but recent declines in sea otters and sea stars on the West Coast have led to an explosion in the number of urchins.

In California, kelp forests are more extensive and resilient to climate change where sea otters have reoccupied the coastline. Where sea otters are absent, kelp forests have declined dramatically. In fact, sea otter population density is the strongest predictor of change in kelp canopy coverage.

But don’t count the kelp forests out yet. A recent discovery proves that these ecosystems are far older than we thought and thus have been through more environmental stress than we imagined. And along California’s Central Coast, growth of the southern sea otter population is helping kelp forests expand by increasing resilience to environmental challenges—including extreme ocean warming—nearly compensating for the kelp losses along both Northern and Southern California shores. In Patagonia, the giant kelp of the rugged southwest coast is thriving, showing remarkable stability for almost 200 years.

Pacific kelp forests: “old growth”

The unique underwater kelp forests that line the Pacific Coast support a varied ecosystem that was thought to have evolved in conjunction with kelp over the past 14 million years. But a new study published in the journal Proceedings of the National Academy of Sciences in January 2024 reveals that kelp flourished off the Northwest Coast more than 32 million years ago, long before the appearance of modern groups of birds, bivalves, marine mammals and sea urchins that today call the forests home.

The much greater age of these coastal kelp forests means that they likely were a main source of food for an ancient, now-extinct mammal called a desmostylian. The hippopotamus-sized grazer is thought to be related to today’s manatees, sea cows and their terrestrial relatives, elephants.

Coastal kelp forests were probably a main food source for an ancient, now-extinct mammal called a “desmostylian.” This hippopotamus-sized grazer is thought to be related to today’s manatees, like the one shown here.

Scientists didn’t think kelp were older than 14 million years because the organisms associated with the modern kelp forest were not there yet. But this study shows that the kelp were there; it’s just that all the organisms that researchers expected to be associated with them were not.

Evidence for the greater antiquity of kelp forests comes from newly discovered fossils—found along the beach near Jansen Creek on the Olympic Peninsula in Washington state—of kelp holdfasts, the root-like kelp parts that anchor them to rocks or rockbound organisms on the seafloor. The stipe, or stem, attaches to the holdfast and supports the blades, which typically float in the water, thanks to air bladders.

The authors of the study dated these fossilized holdfasts to 32.1 million years ago, in the middle of the Cenozoic Era, which stretches from 66 million years ago to the present. It was determined that the holdfasts lived in slightly warmer water than that of today, at the upper range of temperatures found in modern kelp forests. The oldest previously known kelp fossil, consisting of one air bladder and a blade similar to that of today’s bull kelp, dates from 14 million years ago and is in the collections of the University of California Museum of Paleontology.

Newly discovered fossils of kelp holdfasts, the root-like parts that anchor kelp to rocks or rockbound organisms on the seafloor, provide proof of the greater antiquity of kelp forests. The stipe, or stem, attaches to the holdfast and supports the blades, which typically float in the water.

The only order of mammals that went extinct during the Cenozoic Era are the desmostylia. Kelp had long been suggested as a food source for these marine mammals, but actual evidence was lacking. The newfound fossil holdfasts indicate that kelp is a likely candidate.

These early kelp forests, however, were probably not as complex as the forests that evolved by about 14 million years ago. Detailed, 3D, X-ray scans through slices of the 32.1-million-year-old fossils revealed a barnacle, a mussel, a snail and tiny, single-celled foraminifera hidden within the holdfast, in addition to the bivalve on which it sat. That diversity of invertebrates, though, is not as high as would be found inside a kelp holdfast today. Fossils from the late Cenozoic along the Pacific Coast indicate an abundance of bivalves (clams, mussels and oysters), birds and sea mammals—including sirenians, related to manatees—and extinct, bear-like predecessors of the sea otter called Kolponomos. At 32.1 million years ago, the diversifying of organisms living in kelp forests had not yet started.

Kelp helper: sea otters

Moving ahead in time to just the past century, one of the biggest kelp forest supporters has been the sea otter.

Southern sea otters were hunted to near extinction during the fur trade of the 1700s and 1800s. They survived because a few dozen animals eluded hunters off the rugged coast of California’s Big Sur.

In a paper published in the journal PLOS Climate in January 2024, California’s Monterey Bay Aquarium researchers show that sea otter population growth during the last century enhanced kelp forest resilience in the state. In fact, over the more-than-100-year period from 1910 to 2016, there was a significant increase in kelp forest canopy along the Central Coast, the only region of California where southern sea otters survived after being hunted nearly to extinction for their fur in the 1800s. At the century scale, the species’ favorable impact on kelp forests along the Central Coast nearly compensated for kelp losses along both Northern and Southern California coasts, resulting in only a slight overall decline statewide during this period.

Aquarium scientists used historical surveys of kelp forests dating back to the early 1900s to perform detailed estimates of biomass, canopy extent and carbon storage, while correcting for annual variations and differences in survey methods. This allowed the scientists to examine California’s kelp forest trends over a longer period, going back more than 60 years before available data from modern surveys based on aerial or satellite imagery. The team compared the corrected and conservative historical estimates to contemporary datasets, and then they used a machine-learning framework to assess the dominant drivers of change over the last century.

Statewide, the data showed only a 6% decline in kelp canopy from 1910 to 2016. Regional changes, however, proved more sizable. Kelp canopy decreased in northern and southern regions by 63% and 52%, respectively. Contrastingly, it increased nearly everywhere throughout the Central Coast, gaining an estimated 56% of kelp forest coverage.

Recently, the U.S. Fish and Wildlife Service announced that reintroducing sea otters to the Oregon coast would be feasible. It would help restore kelp forests to ecological balance by cutting down on the number of sea urchins.

While the modeling showed sea otter population density was the strongest predictor of change in kelp coverage, it also identified other factors, including extreme marine heat due to climate change. Today, extreme heat in the ocean affects more than half of its surface. This is a major problem for kelp forests, as chronic temperature stress undermines kelp growth and health. Returning sea otters to areas of their historical range could help recover kelp forests and restore their benefits in more places along the California coast.

Another kelp helper: Patagonia’s cool coastal waters

While giant kelp forests around the world have struggled to stay healthy in recent decades—with some vanishing altogether—Patagonia’s giant kelp forests, on the southern tip of Chile, look just as they did in the early 20th century.

Heat waves can drive changes in what species inhabit kelp forests, such as sea urchins and the sea otters who snack on them in the Northern Hemisphere. But high sea temperatures can also stress kelp directly, as kelp are best adapted for cooler waters. In northern and central Chile, unregulated direct harvesting by humans is devastating kelp forests, too. These threats have degraded many kelp forests over recent decades and led to losses of 2% every year.

Along Patagonia’s rugged southwestern coast, giant kelp is thriving. It’s thought that frequent marine cold spells could be keeping kelp happy.

But nautical charts as far back as Charles Darwin’s 1831 HMS Beagle expedition and modern satellite imagery of kelp forests show that little has changed around Patagonia, despite climate change and human influence. To find out why, researchers analyzed sea surface temperatures from the southernmost 800 miles of South America’s coastlines from 1981 to 2020. They were looking for marine heat waves and cold spells. While heat waves stress kelp forests, they wondered what impact cold spells could have.

When glaciers melt, more cold water enters the ocean environment. This can create very short peaks in cool temperatures, from a few days to two to three weeks. Cool waters can act like air-conditioning for kelp, regulating their environment and keeping temperatures comfortable. The researchers, who published their report in the Journal of Geophysical Research: Oceans in June 2022, found that South America’s southwestern giant kelp forests haven’t experienced an extreme marine heat wave since 1984 and, in fact, the area has had regular marine cold spells that are growing more intense. From 2014 to 2019, the region saw more severe and extreme cold spells than over the rest of the study period. Glacial melt and increased wind activity could explain these quick, localized cooling events. (Wind patterns that affect ocean surface circulation, heat fluxes or cold water traveling around Antarctica could also be factors.)

The outlook for these kelp forests may stay bright, at least for the immediate future. Current climate and ocean models predict that the Southern Ocean, the waters in which these thriving kelp forests live, will avoid dramatic warming. But as glacial melt increases, that freshwater can bring with it sunlight-blocking sediment, different sets of nutrients and even too-cold temperatures. Scientists don’t yet have well-defined windows for how long different kelp species can tolerate extremely cold water.

In southern Patagonia, most of the lands surrounding the kelp forests are protected. However, that’s not always the case regarding the waters.

In addition, in southern Patagonia, most of the lands surrounding the kelp forests are protected, but not necessarily the waters. And in the northern regions of Chile, kelp forests are harvested for the alginate industry (alginate has applications in the dyeing, cosmetic, food, pharmaceutical, printing and textile industries), creating underwater deserts in environmentally favorable conditions. The researchers conclude that environmentalists, local communities, nongovernmental organizations and current governments should make kelp protection a priority.

Kelp continuance: otters and onward

Healthy kelp forest ecosystems provide us with many benefits, including contributing to carbon storage, reducing coastal erosion from storms and serving as nursery grounds for fisheries. And once washed up on the beach, kelp wrack plays a major part in the beach food web, feeding a highly productive community of small invertebrates—crustaceans and insects—that are in turn a favorite food of shorebirds. In many ways, we’re still on the cusp of learning more about the value kelp forests have for the environment and, thus, for us.

The conservation and recovery of endangered sea otters is one potential, nature-based solution for restoring kelp forests along the California Coast—and, perhaps, beyond.

Here’s to finding your true places and natural habitats,

Candy

The post Kelp: Coastal Sea Otter Help and Patagonia Cold Comfort first appeared on Good Nature Travel Blog.