Featured Creature: Beaver

Photo by Derek Otway on Unsplash

Which creature fights fires, creates wetlands, recharges groundwater, alters landscapes, and is a climate hero?

Beavers!

Photo by Derek Otway on Unsplash

At Bio4Climate, we LOVE beavers. We’re borderline obsessed with them (or maybe not so borderline) because they do SO much for Earth’s ecosystems, natural cycles, and biodiversity. These furry, water-loving creatures are finally beginning to receive the recognition they deserve in mainstream media now that more people see how their existence and behaviors lead to numerous benefits for everyone’s climate resilience.

We are one of the many organizations advocating for their reintroduction across North America and some places in Europe. For this reason, when I spotted one on a hike during my time in Tennessee, I did what any Bio4Climate team member would do: jump in excitement, yell out “Oh my gosh it’s a BEAVER!” and take a picture that I’ll treasure forever.

Photo by Tania Roa

The rockin’ rodent

Beavers live in family groups of up to eight members. Offspring stay with their parents for up to two years, meanwhile helping with newborns, food gathering, and dam building. To create dams, beavers use their large teeth to cut down trees and lug over branches, rocks, and mud until they successfully slow down the flow of water. These dams include lodges that beavers use as bedrooms and to escape from predators. Dams are designed according to the water’s speed: in steady water, the dam is built straight across, and in rushing water the dam is built with a curve. These engineers build their dams in a way that makes them nearly indestructible against storms, fires, and floods.

Look at those bright orange teeth! The color is thanks to an iron-rich protective coating. Beaver teeth grow continuously, and require gnawing on trees for trimming.

Photo by Denitsa Kireva: Pexels
Photo by tvvoodoo on Freeimages.com

Furry firefighters

Beaver dams are what make these rodents, the largest ones in North America, so special. When dams alter the flow of water, they create ponds that stretch out a river into a wide wetland. These ponds filter pollutants and store nutrients that then attract a variety of wildlife including fish seeking nurseries, amphibians looking for shelter, and mammals and birds searching for food and water sources.

The abundance of wildlife and the storage of necessary nutrients in beaver ponds classifies these places as biodiversity hotspots, meaning they are “biogeographic regions with significant levels of biodiversity that are threatened by human habitation” (Wikipedia). Beaver ponds also store sediment, and this helps recharge groundwater. Due to the sheer wetness of these ponds, and how deep the water filters into the soil, fires are often extinguished as soon as they reach a beaver pond. In this way, beavers are nature’s firefighters, of which we need many more in areas where extreme heat is increasing.

“There’s a beaver for that”
Ben Goldfarb

  • Wetland Creation
  • Biodiversity Support
  • Water Filtration
  • Erosion Control
  • Wildlife Habitat
  • Flood Management
  • Drought Resilience
  • Forest Fire Prevention
  • Carbon Sequestration
  • They’re Cool (pun intended)

Beavers are considered ‘ecosystem engineers’ because they actively shift the landscape by fluctuating the flow of water and the placement of plants and trees. Muskrats, minks, and river otters also find refuge in beaver lodges. When beavers take down trees, they create pockets of refuge for insects. Using their constructive talents, beavers significantly modify the region and, in turn, create much-needed habitat for many. Numerous creatures rely on beaver dams for survival, and the local ecosystem dramatically changes when a beaver family is exterminated; for these reasons, we also consider them ‘keystone species.’

Disliked dam builders

Despite the positive impact beavers have on biodiversity and ecosystems, we humans have viewed them as fur, pests, and perfume. By 1900, beavers went nearly extinct across Europe and North America. We hunted them for their fur in response to fashion trends, and trapped them for their anal musk glands, or castors, which produce castoreum, a secretion that beavers use to mark their homes and that humans use to make perfume. When beaver populations plummeted, so did the number of dams and ponds, meaning vast swaths of land were drastically altered during this time – and not for the better. To this day, we kill beavers when they wander into military bases or near urban areas since we see their dam-building behaviors as potentially damaging to man-made properties.

Thankfully, as more ‘Beaver Believers’ speak out against these practices and more authorities recognize the importance of beaver benefits, these rodents are beginning to return to their original homes. California recently passed a program specifically for beaver reintroduction efforts across the state. Washington, Utah, and Massachusetts are other states witnessing the return of beavers. People like Skip Lisle of Beaver Deceivers are designing culverts that prevent beaver dams from damaging infrastructure, but allow the beavers to create their biodiverse-filled ponds. These are just a few examples of the ways we can coexist with beavers, and in turn heal our communities.

Beaver Dam on Gurnsey Creek commons.wikimedia.org

Climate heroes

There are places in North America where water sources are decreasing for all living things, and in other regions the amount of rainfall is increasing while the amount of snow is decreasing. These weather conditions are detrimental to all of our health, unless we welcome back beavers.

As the effects of climate change and biodiversity loss increase, storing water, preventing runoff and erosion, and protecting biodiverse hotspots become more important by the hour. By restoring local water cycles, beaver ponds provide a source of life. By spreading water channels and creating new ones, beaver dams prevent flooding and stave off wildfires. By encouraging the cycling and storage of nutrients, beaver ponds nurture soil health and that leads to carbon sequestration. We all have something to gain from beavers as long as we allow them to do what they do best: build those dams.

To learn more about beavers, watch the video below and the two in the ‘Sources’ section. We also highly recommend Ben Goldfarb’s Eager: The Surprising Secret Life of Beavers and Why They Matter for further reading.

For all creatures that deserve a feature,

By Tania Roa


Sources:
Why BEAVERS Are The Smartest Thing In Fur Pants
Why beavers matter as the planet heats up 
9 Amazing Beaver Facts
Environmental Benefits of Beavers – King County 
8 Facts to Celebrate International Beaver Day | Smithsonian’s National Zoo 

Featured Creature: Giant Barrel Sponge

What creature grows tall and sturdy, cleans up its neighborhood, and defends itself from predators – all without moving a muscle?

The Giant Barrel Sponge, or Xestospongia muta!

Photo By Twilight Zone Expedition Team 2007, NOAA-OE – NOAA Photo Library (Public Domain, via Wikimedia Commons)

A Giant Barrel by any other name… 

Giant barrel sponges are aptly named for their shape and great size. They grow over 1 m tall, but only grow an average of about 1.5 cm a year. After all, good things take time! 

Giant barrel sponges come in a range of colors, depending on the presence of the cyanobacteria that they work with in symbiosis. They can be pink, purple, brown, reddish brown, and gray, and tend to be different colors at different depths. 

You may be wondering why this “giant barrel” doesn’t look very much like Spongebob Squarepants, or the sponge you use to clean up in the kitchen. Well sponges, or animals of the phylum Porifera, come in all shapes and sizes, and there is great diversity among the 8,550 species of them. Sponges are quite ancient, with their oldest fossil records dating back 600 million years, so they’ve had time to differentiate and find their own ecological niches.

The giant barrel sponge is known as the “Redwood of the Sea.” The phrase comes from the fact that giant barrel sponges share the tendency for individuals to live long lives, from a few hundred to thousands of years old. In fact, the oldest known giant barrel sponge is over 2000 years old. 

Old age isn’t the only thing they have in common with their counterparts on land. Like the magnificent redwoods, they do wonders to clean up and support the environment around them. Giant barrel sponges can filter up to 50,000 times their own volume in water in a single day. They also provide habitat to several small fish and other invertebrates that can be found living inside or on the surface of the sponge.

Photo by Andre Oortgijs (CC BY-SA 3.0 via Wikimedia Commons)

How does such a giant creature sustain itself?

Although giant barrel sponges are, well, giant, their diet is anything but. These creatures, like many species of whales, sustain their size not by eating very large sources of food, but by eating large volumes of it. Giant barrel sponges are filter feeders, and consume microorganisms from the water around them that they pump through their bodies. The sponges have special cells along their inner cavities called choanocytes, which work to facilitate the movement of water and the capture of food from it.

In their ocean food chain, giant barrel sponges take their place above their symbiotic partners cyanobacteria, and are consumed in turn by macroorganisms like fishes, turtles, and sea urchin. They try to defend themselves by releasing chemicals to repel their predators, but there’s only so much they can do when stuck in one place, waiting to be ingested by so many types of marine life. Like other filter feeders, giant barrel sponges ultimately form an important branch in the transfer of nutrients from very small to much larger life forms.  

They don’t even have tissues, let alone organs, but their simple structure is more than enough to ensure their survival and proliferation. Giant barrel sponges reproduce by spawning, and are one of the few species of sponge that undertake sexual reproduction. Males and females release sperm and egg cells into the ocean synchronously, so that when the time comes, they have a chance of contributing to a fertilized egg that grows into a larva and, after being carried by currents to a new spot of the ocean floor, establishes itself as an independent sponge. 

Check out this short video of the spawning phenomenon:

A valued community member

Giant barrel sponges are native to the oceans of the Americas, found primarily in the Caribbean Sea, and observed as far south as the coasts of Venezuela. 

Due to their filtration capabilities, giant barrel sponges are real assets to the ecosystems they are a part of, but boosting water quality is not the only ecological role they play. As mentioned, many other creatures live in and around the cavernous sponges, and giant barrel sponges are one of the largest organisms in the coral reef environments where they are found. They are thought to help coral anchor to substrate (the mix of mineral, rock, and skeleton that binds reefs together), and themselves make up about 9% of coral reef substrate in certain areas where they are found. By helping in this binding process, giant barrel sponges can play an important role in reef regeneration. 

Though the giant barrel sponge is not currently classified as threatened, like all of us, it is living in vulnerable times, as reef habitats are weakened in warming, acidifying waters. It is susceptible to a disease called Sponge Orange Band disease that afflicts all kinds of sponges. They can also be damaged or killed by human activities that disturb reefs and break sponges off from their surroundings. 

On the flip side, when these great creatures are doing well, they enable the thriving of life all around them. May all of us aspire to say the same.

With one giant smile,
Maya


Maya Dutta is an environmental advocate and ecosystem restorer working to spread understanding on the key role of biodiversity in shaping the climate and the water, carbon, nutrient and energy cycles we rely on. She is passionate about climate change adaptation and mitigation and the ways that community-led ecosystem restoration can fight global climate change while improving the livelihood and equity of human communities. Having grown up in New York City and lived in cities all her life, Maya is interested in creating more natural infrastructure, biodiversity, and access to nature and ecological connection in urban areas.


Sources and Further Reading:
https://animaldiversity.org/accounts/Xestospongia_muta
https://oceana.org/marine-life/corals-and-other-invertebrates/giant-barrel-sponge
https://en.wikipedia.org/wiki/Giant_barrel_sponge
https://www.americanoceans.org/species/giant-barrel-sponge
https://oceanservice.noaa.gov/facts/sponge.html

Featured Creature: Dragonfly

Which creature existed before the dinosaurs, is an aerial genius, and can detect things we can only witness through slow-motion cameras?

The dragonfly!

Eugene Zelenko (CC BY-SA 4.0 via Wikimedia Commons)

Predecessors to the Dinosaurs

Dragonflies were some of the first winged insects to evolve, about 300 million years ago. When they first evolved, their wingspans measured up to two feet! In contrast, today’s dragonflies have wingspans of about two to five inches.

Although in this feature we speak of dragonflies in a general sense, there are more than 5,000 known species of them, each with its own characteristics. 

The Dramatic Entrance

Dragonflies begin as larvae. During this almost 2-year stage, they live in wetlands such as lakes or ponds across every continent except Antarctica. Despite their small size, their appetite is huge, and they are not picky eaters. In their larval to nymph stages, they will eat anything they can grasp including tadpoles, other insect larvae, small fish, mosquitos, and even other dragonfly larvae. 

After their nymph stage, dragonflies emerge as if they were reviving from the dead. They crawl out of the water, split open their body along their abdomen, and reveal their four wings- along with their new identity. Then, they spend hours to days drying themselves before they can take to the skies as the insects we know and love. 

Once a dragonfly is dry and ready to fly, their voracious appetite continues. As usual, they’ll eat almost anything, but now they will only eat what they catch mid-flight. These feasts consist of butterflies, moths, bees, mosquitoes, midges, and, yet again, even other dragonflies. They seem to embrace the motto “every fly for themself.”

Check out their dramatic transformation:

Engineered for Optimal Flight

Dragonflies emerge after their larval stage as masters of the air. Their four independently moving wings and their long, thin bodies help them maneuver the skies. They hunt and mate in mid-air and they can fly up to 60 miles per hour. They are also able to fly backwards, sideways, and every which way in a matter of seconds or less. 

This incredible ability requires excellent vision. (Or else we would likely see them crash much more often!) Thankfully, dragonflies have just the answer. Their head mostly consists of their eyes. Their multiple lenses allow them to see nearly everything around them, covering every angle except one: right behind them. The insect’s vision not only reaches far and wide, but allows them to see the world at faster speeds than we can.

How are human activities impacting dragonflies?

Since dragonflies consume a variety of organisms, and rely on healthy bodies of water to grow, they are considered important environmental indicators. In other words, when dragonfly populations plummet, conservationists have something to worry about. Nymphs and dragonflies will eat just about anything, so they will only go hungry if there is no available food. Looks like those big appetites came in handy after all. 

Declines in dragonfly populations also indicate water pollution and habitat loss. These are consequences of agricultural methods that favor chemicals and synthetic fertilizers, and forest management that disregards the importance of maintaining balance within an ecosystem. One solution is regenerative agriculture which ensures fewer toxins in our environment. 

Overall, the more green (and blue) space for wildlife, the more likely these iconic insects will thrive. 


Tania graduated from Tufts University with a Master of Science in Animals and Public Policy. Her academic research projects focused on wildlife conservation efforts, and the impacts that human activities have on wild habitats. As a writer and activist, Tania emphasizes the connections between planet, human, and animal health. She is a co-founder of the podcast Closing the Gap, and works on outreach and communications for Sustainable Harvest International. She loves hiking, snorkeling, and advocating for social justice.


Featured Creature: Pacific Salmon

This week we ask,

What creatures navigate oceans, climb mountains, feed forests, and motivate us to destroy renewable energy infrastructure?

The Pacific Salmon!

USEPA Environmental Protection Agency (Public Domain via Wikimedia Commons)

How do salmon find their way home?

Pacific salmon are famous for their migrations from the saltwater habitats they live in as mature adults to the freshwater rivers and streams where they were born and return to spawn. Salmon have two means of finding their way back to where they first hatched, often to the very same patch of gravel.

In the open ocean, they have a GPS system based on the earth’s magnetic fields sensed through their lateral line (a highly-sensitive line of nerves running down each side of their bodies). When they get near shore, they then follow smells that they imprinted from their natal river up to where they originally hatched, to spawn again and continue this cycle.

How do salmon manage to get back upstream?

Salmon make their way back home against the current of streams and rivers, even climbing mountains in the process. As they go, they feed upland forests by transporting ocean nutrients into the headwaters of their natal streams, supporting all kinds of life in the process (and not just hungry bears)!

Istvan Banyai (CC BY-SA 3.0 via Wikimedia Commons)

What happens to Pacific salmon after they successfully spawn?

Spawned-out Pacific salmon all die after completing their journey. In late fall, on a salmon river, rotting corpses and dying fish appear everywhere, white with mold and stinking with decay. In doing so, they feed forests and the aquatic life that sustains the next generation of fish when they hatch in the spring. We don’t really know why they all die after spawning, unlike the Atlantic salmon, which live after the process is complete. 

Bears also increase the ecological reach of these salmon by catching them in rivers and streams and carrying them deep into the forest to feast. This brings their helpful nutrients, particularly nitrogen, into dense stretches of forest where they can fertilize the ecosystem and help trees grow. In fact, it is estimated that eighty percent of the nitrogen in the trees of the Great Bear Forest in Canada comes from salmon. Learn about the interdependent links of salmon, bears, and forest health here.

Where do we find Pacific salmon?

Pacific salmon are an anadromous species, which means they live in seawater but spawn in freshwater. They hatch from eggs in gravel and spend their early years in freshwater rivers up high in the mountains and forests along the Pacific coast. Then, once they reach about 6-8 inches in length, they move down through the estuarial waters to spend several years in the open ocean, feeding and growing large, before they journey upstream to spawn and die.

What is the cultural significance of these fish?

Pacific salmon are part of a religious cycle of life for Indigenous peoples on the American and Canadian West coasts as well as across the planet. Their annual return is celebrated as part of a natural process in which Autumn brings a bountiful harvest of fish to add to other stores of food to last through a long cold winter. Salmon are objects of worship by coastal native inhabitants, human and nonhuman alike, who depend on the annual return of these salmon in the fall to help them get through a long cold winter.

A Shoshone-Paiute tribal member during the reintroduction of the Chinook Salmon
into the East Fork Owyhee River by the Shosone-Paiute Tribe (May 28, 2015)
(Photo by Jeff Allen, Northwest Power and Conservation Council)

We want renewable energy sources! So why are we destroying them for these salmon?

From the 18th into the 20th centuries, our human thirst for factory power had us constructing many dams on our rivers, with little attention to their harmful ecological impact. Many of our anadromous fish species – adapted to the specific conditions of their river watersheds – were lost forever when dams left them unable to complete their journeys upstream.

It is only in recent decades that a powerful movement for dam removal and habitat restoration has been gaining momentum as a means of saving these precious species. The beneficial effects of removing these barriers have been spectacular, as rivers – freed from their shackles – blossom with new life. Along with the salmon have come a revival of other runs, including steelhead, herring, eels, shad and other diadromous fish (ones that transition between freshwater and saltwater environments), as well as birds and wildlife previously not seen in these areas. Our rivers are showing us all that we had lost and all the flourishing that is possible once we get out of their way.

How are human activities impacting these salmon?

Pacific salmon are in serious trouble. A thirst for hydropower has placed them at dire risk of extinction. We are removing dams, building fish ladders on existing dams (since their proper design is crucial), making sure culverts and other means of fish passage stay open and unhindered. But salmon are cold water species, so a warming planet puts them in peril.

However, there is much we can do to protect them, and restore them once they are threatened or lost. Several short but informative videos on salmon restoration efforts can be found here and here.

May we keep supporting the Pacific Salmon,

Fred


Fred is from Ipswich, MA, where he has spent most of his life. He is an ecological economist with a B.A. from Harvard and a Ph.D. from Stanford, both in economics. Fred is also an avid conservationist and fly fisherman. He enjoys the outdoors, and has written about natural processes and about economic theory. He has 40 years of teaching and research experience, first in academics and then in economic litigation. He also enjoys his seasonal practice as a saltwater fly fishing guide in Ipswich, MA. Fred joined Biodiversity for a Livable Climate in 2016.