By Watershed Protection Program Co-op Sarah Barker

Deep in the sleepy haze of a deciduous forest dawn, between bowing black willows and proud sycamores, a lovely little creature works his way back home. Charlie Woodscomb, known to his family and friends as “Chompy” — although he much preferred his given name (even if he wouldn’t admit it to his loved ones) — pattered through the brush towards his warm lodge, ready for a long day’s rest after patrolling his territory throughout the moonlit night. It had been an average night’s work, collecting alder shoots and a bit of aspen for his cache. Along his meandering route, he paused for a moment to smell the air for any signs of unwelcome guests in his modest kingdom. Beavers may be the proud engineers of this landscape, but even Charlie could admit that vision wasn’t their strongest asset. However, his mighty clan made up for this shortcoming with many other wonderous capabilities.

Once he had confirmed with both his powerful nose and sensitive ears that no trouble seemed to stand in between him and his cozy den, he resumed his leisurely promenade, admiring the sounds of water crashing over the many riffles as it danced down to his stately abode. The lodge was something to behold alright! As he stopped to reflect on how lucky he was, he began to reminisce. He had poured countless dark and rainy nights into the lodge’s construction with his beautiful wife, Sandy. For several lonely months before meeting Sandy, he had scouted and prepared this particular stretch of the meandering stream they now called home. 

Charlie had left his parents’ den shortly after his second harvest moon, having decided that it was time to set off and establish a home of his own. He had grown up in a wonderfully large and boisterous family, he had enjoyed playing with his younger siblings, taking turns grooming their thick fur, and contributing to the nightly patrol as he got older and could take on more serious responsibilities. Eventually, he began to long for a home he built himself, a warm shelter where he could protect and take care of his future mate and litters of kits from the harsh winters and raging storms. So, he set off to face the great beyond, taking his first pioneering steps from the valleys of the ancient mountains he called home, onward towards meadows and wetlands just as his father had done many ripe moons ago.

After traveling for several long nights, he found his new home in these gorgeous woodlands, full of dense swaying canopies. The sheer amount of foliage and freshly sprouted woody shoots made his mouth water immediately! He knew that this hidden oasis would be perfect for his future family, and he wasted no time in skittering down the stream bank to find a nice bend on which to begin his very first dam. However, he faced many obstacles in these abundant lands. Just as he had discovered this cornucopia of lush greenery, other creatures of the forest soon began to wander through the area in search of nourishment. Most were not threatening to him, and included friendly songbirds picking at the juicy serviceberries and a couple of muskrats hoping for a tasty cattail snack. These friends he greeted with a kind hum. He had enjoyed socializing with his fellow beavers back at his parents’ den, and so he relished these brief encounters, however fleeting; that was, until he first spotted the red fox. 

Charlie had seen first-hand the devastation these cunning predators could unleash upon a family, and so he made sure to scent-mark his territory vigilantly, hissing and slapping his tail against the water whenever that cursed creature came too close. Thankfully, he was pretty large for his age, and in wonderful shape due to his tireless construction efforts and incessant swimming. The fox carefully backed away upon hearing the powerful sharp snap of his tail, realizing his strength, and recognizing that he would be much more trouble than a quick meal was worth.

Every so often, Charlie would catch a glimpse of crimson fur between the box elders and red maples, but soon enough, the fox gave up on his territory, moving on to find a more vulnerable source of calories. Charlie breathed a great sigh of relief once he noticed this departure, as he had begun to worry that he would have to find another meander to call home. 

His peace was only short lived however, as but a few weeks after the fox had left, the rain began. Normally, he loved a good bit of rain; it expanded his swimming range and allowed him access to new, temporary tributaries or ephemeral pools for even more delicious treats, but this rain was ferocious and unrelenting. He tried his best to prevent the downpours from washing away all his hard work, but mother nature could not be bested, not even by a mighty beaver such as himself. After two long weeks of brutal battering, the great progress he had made on his new dam disappeared downstream, along with the cache of twigs he had begun to stock up for the winter.

Heartbroken and downtrodden, Charlie wondered if he should give up and look for another stretch of river to build his home, but the cold was creeping ever closer and there was no guarantee that there would be suitable foraging grounds further downstream. He had found himself in a great big pickle indeed. After several debates with himself which led to nowhere, he decided to put a pause on his pity party and go for a nice moonlit swim to clear his head; he found that he always had his best ideas when he was diving for submerged morsels. As he started the trek toward his usual mud slip, he began to pick up the scent of someone new. He paused for a moment to focus on the unfamiliar perfume, hesitant at first, for fear that another tricksy fox had happened upon his territory and was now lying in wait for him.

However, he was surprised and intrigued when he realized that he was smelling another beaver, one with whom he was not previously acquainted! Charlie, now full of excitement and anxiety at the thought of finally meeting another fellow beaver, sped down the small trail he had gradually carved out over the past few weeks, and headed toward the stream bank. But once he saw the gorgeous, shiny dark fur in front of him, his heart skipped a beat. The mysterious visitor turned to greet him, and he fell in love all at once. She introduced herself to him with a hum. Her name was Sandy, and he thought that she had lovely teeth and beautiful paws.

Now after two blissful Beaver moons together, they were finally expecting their first litter of kits, much to Sandy’s and his delight! They had enjoyed their time together as a couple, but they were quite eager to welcome the fun and happiness that little ones would certainly bring to their newly expanded accommodations. Sandy and Charlie had worked tirelessly on their pristine dam, homey lodge, overflowing food cache, and sprawling trails that weaved throughout their foraging territory. Charlie, stuck in his nostalgic musings, startled a bit when Sandy herself got his attention with a whine. She had just returned from her night’s foraging and patrolling as well, and was eager to settle down into the warmth of their den for a good day’s rest. Charlie easily obliged, following her into the small pool in front of their comfortable home. As the sun began to rise, he thought about how he was oh so grateful that he didn’t abandon this flourishing land and all the surprising richness it had to offer.

Glossary: terms listed in order of appearance

Cache | Caches are collections of various branches, twigs, and other woody debris which are stashed in a submerged location near the resident Beaver’s lodge as a method of long-term food storage in case of storm events preventing active foraging and as a stockpile for the winter months when Beavers rarely leave their dens to conserve heat and energy.

Harvest Moon | Each full moon corresponding to a calendar month has a traditional name which denotes what is happening in the environment during that season. This system was developed centuries ago by Native American tribes and while some names differ depending on the tribe, there is a general twelve-moon, twelve-month list which is still in use today in the Northern hemisphere! The Harvest moon represents September due to the abundance of crops ready for harvest during early fall.

Smelling Another Beaver | Beavers can tell from scent alone the age, sex, and relative social class (dominant vs. subordinate) of another beaver from its scent. Castoreum which is the substance produced by beavers to scent-mark is unique to the individual beaver and plays an essential role in both territorial defense and communication. There is evidence to suggest that this high level of recognition can help to prevent inbreeding or mating outside of the established mating pair. These processes can help beavers to avoid the negative effects of inbreeding on genetic diversity or prevent hostile or apathetic behavior from a mate in response to unrelated kits in the family lodge. However, these mating traits can change depending on the range of dispersal of beaver pairs and obstacles preventing ideal mating such as heavy snowfall.

Beaver Moon | The Beaver moon coincides with November as an indicator of the intense preparation and increased activity level of beaver families preparing for winter at this time of year.

References:

Coolman, Aaron (2023). [A beaver swimming in a shallow stream] [Photograph]. Willistown Conservation Trust.

Rosell, F. N., & Campbell-Palmer, R. (2022). Beavers: Ecology, behaviour, conservation, and Management. Oxford Academic. Oxford University Press. Retrieved June 1, 2023, from https://academic.oup.com/book/38841/chapter-abstract/337749534?redirectedFrom=fulltext. 

By Watershed Protection Program Co-op Sally Ehlers

The northern snakehead (Channa argus) is a type of fish that is originally from Asia which has made its way to Pennsylvania and is causing problems in local streams. In 2004, an angler found a northern snakehead in Meadow Lake in FDR Park in Philadelphia County. This was the first confirmed sighting of this type of fish in Pennsylvania. 

About a year later, there was a recorded catch in the Delaware River. They have since spread through canals, reservoirs, lakes, and rivers along the East Coast and as far west as the Mississippi River. The presence of the northern snakehead is worrisome because it can be harmful to other fish and their homes. The northern snakehead is a voracious predator and eats other fish. This aggressive behavior can reduce the number of other fish in a waterway. Northern snakeheads will compete with other fish for food and habitat.

One thing that makes the northern snakehead unique is its ability to survive in water with many different levels of dissolved oxygen. Even if there is not a lot of dissolved oxygen in the water, the northern snakehead can still survive. This is because it has a special organ called a suprabranchial organ, or primitive lung. This organ allows the northern snakehead to breathe air directly from the atmosphere. They can even survive out of water for up to four days if they stay moist. This adaptation, in combination with its ability to move across land for short distances by wriggling on its fins, allows it to easily travel from one body of water to another.

To stop the northern snakehead from spreading, the Pennsylvania Fish and Boat Commission has made some rules: 

1. Do not keep or sell northern snakeheads. 
2. Do not release them into other bodies of water. 

This ensures the northern snakehead does not continue to spread.

The Pennsylvania Fish and Boat Commission is also working hard to teach people how to identify the northern snakehead. If people know what to look for, they can help make sure it doesn’t spread to other areas. The northern snakehead has some distinctive features, such as a long body with a single fin running along the length of the back, a somewhat flattened head, and a brown body with dark blotches.

The northern snakehead can be confused with the native North American Bowfin (Amia calva). In the western part of Pennsylvania, northern snakeheads may also be confused with burbot (Lota lota). These species have similar body shapes and coloration, however, there are some key differences. As the name implies, the northern snakehead has enlarged snake-like scales on its head. The Northern American Bowfin does not have scales on its head, rather it has bony plates between its lower jaw bones. The burbot has a scaly head, but unlike the northern snakehead, it has two fins on its back. 

If you catch a northern snakehead, it is essential to report it to the Pennsylvania Fish and Boat Commission by calling 815-359-5163 or visiting their website. You are also encouraged to kill it, freeze it, and record the location where you found it. This information is useful for figuring out the geographic range of the northern snakehead and possibly finding ways to control its spread.

References:

“California’s Invaders: Snakehead,” California Department of Fish and Wildlife,

https://wildlife.ca.gov/Conservation/Invasives/Species/Snakehead#:~:text=Snakeheads%20have%20small%20heads%20with,days%2C%20if%20they%20stay%20moist

“Northern Snakehead,” Chesapeake Bay Program,

https://www.chesapeakebay.net/discover/field-guide/entry/northern-snakehead

“Northern Snakehead,” Pennsylvania Fish and Boat Commission,

https://www.fishandboat.com/Fishing/All-About-Fish/Catch-PA-Fish/Pages/Snakehead.aspx

“Northern Snakehead,” Pennsylvania Sea Grant, https://seagrant.psu.edu/sites/default/files/snakehead2013_reduced_0.pdf

“Northern Snakehead Fish,” Smithsonian’s National Zoo and Conservation Biology Institute, https://nationalzoo.si.edu/animals/northern-snakehead-fish

By Watershed Protection Program Co-op Sally Ehlers

Have you ever heard of the New Zealand mudsnail (Potamopyrgus antipodarum)? These tiny creatures, each just a few millimeters long, are causing big problems in some Pennsylvania streams and rivers.

The New Zealand mudsnail is an invasive species, which means it is not native to the area where it is now living. This species is native to the freshwater streams and lakes of New Zealand and neighboring islands. They do not cause any trouble there because native parasites and predators keep their populations from growing too large. 

However, in the United States, this species has no natural parasites or predators, which allows populations to explode in waterways where they are introduced. This species was first discovered in the United States in the late 1980s, and it has since spread to many different parts of the country, arriving in Pennsylvania in 2006. In Pennsylvania, New Zealand mudsnails have been found in several rivers and tributaries, including the Schuylkill River, Wissahickon Creek, and Wyomissing Creek.

You can identify these snails by looking at their rice-sized shells. New Zealand mudsnails are right-handed which refers to their shell’s coiling direction. When viewed from the top, the shell of a right-handed snail coils clockwise. They also typically have five to eight whorls, or complete rotations of the spiral shell.

One of the reasons the New Zealand mudsnail is such a threat is that it reproduces asexually, so it only takes one snail to spread the population to a new waterway. A single snail can produce thousands of offspring in just one year. In some infested waters, these snails can reach densities of hundreds or even thousands of snails per square foot. That means they can quickly take over habitats and outcompete other species for food and space. One concern is that they could be displacing other snail species that are important food sources for fish and other animals. They also eat a lot of green algae which can result in altered nitrogen levels in the waterway. Changes can potentially hurt the ecosystem’s health because too little nitrogen can stunt plant growth while excess nitrogen can lead to eutrophication. 

These snails can attach themselves to boats, fishing gear, and other equipment. This means that people who fish or kayak in an area with New Zealand mudsnails could unknowingly transport them to other waterways, spreading the invasion even further.

So what can be done to stop the spread of these snails? One important step is to clean your gear thoroughly if you’ve been in contact with infested waterways. This means washing your boots, waders, and other gear. Techniques known to effectively disinfect gear from these mudsnails include putting your gear in the freezer for at least six hours or soaking it in really hot water (greater than 120 degrees Fahrenheit) for at least five minutes. Another way is to soak your gear in chemicals, either a 50/50 mixture of water and Formula 409® Cleaner Degreaser Disinfectant or 2% Virkon Aquatic, for 20 minutes. It is important to note that other cleaning agents, like bleach, are not as effective against New Zealand mudsnails.

The New Zealand mudsnail is a significant issue in some Pennsylvania waterways. By taking steps to prevent their spread, we can help protect our native ecosystems and the animals that depend on them. WCT’s Watershed Protection team has not found any New Zealand mudsnails in Ridley, Crum, or Darby Creek to date, but they continue to check and clean their equipment thoroughly whenever they are working in the field. 

If you find a New Zealand mudsnail, report it to Pennsylvania Fish and Boat Commission by calling 815-359-5163 or visiting their website. 

References:

“New Zealand Mud Snail,” Pennsylvania Fish and Boat Commission,

https://www.fishandboat.com/pages/New-Zealand-Mudsnail.aspx

“PFBC Urges Anglers and Boaters to Help Prevent Spread of Invasive New Zealand Mudsnails,” Pennsylvania Pressroom, https://www.media.pa.gov/pages/fish-and-boat-commission-details.aspx?newsid=445

“Potamopyrgus antipodarum,” U.S. Geological Survey, https://nas.er.usgs.gov/queries/factsheet.aspx?SpeciesID=1008

“Potamopyrgus antipodarum (New Zealand mudsnail),” CABI Compendium,

https://www.cabidigitallibrary.org/doi/10.1079/cabicompendium.43672#toimpactEnvironmental

By Watershed Protection Program Co-op Sarah Barker

Biofilms are all around us! Often thought of as pests in any environment humans find them, these overlooked communities are wonderous mini ecosystems that power some of our most treasured natural habitats. “Biofilm” is a catch-all term used to describe communities of primarily fungi, bacteria, micro and macro algae, viruses, and an ancient group of single-celled organisms called archaea that, together, can thrive in extreme environments, living in a kind of micro-city. Depending on where they are found, the numbers and types of different little creatures living within a given biofilm can change wildly. 

Most of the organisms that live in biofilms are very specific about what conditions they need to survive and thrive. Factors like temperature, light availability, and moisture or humidity can completely change what kinds of algae, fungi, bacteria, archaea, viruses, and other organisms decide to join that community.

Biofilms can be found in any number of places from desert sand to the backs of your teeth! However, your dentists don’t love biofilms, because they can accumulate cavity-causing bacteria if you don’t brush your teeth often enough. Biofilms can also be destructive to man-made objects and buildings. When it comes to water pipes, any submerged concrete, or regular stone buildings, biofilms can worsen natural weathering, create cracks, or even destroy the entire structure given enough time. 

However, biofilms are also, surprisingly enough, quite useful in some industrial, agricultural, and sanitary operations like breaking up toxins from chemical spills and promoting root growth in crops. They can also be used in facilities to treat wastewater for certain kinds of toxins. Studies show that freshwater biofilms serve as an essential “sink” for some toxic trace metals like arsenic. What this means is that they can take up these metals, store them, and over time, turn them into other molecules that can be used by the ecosystem safely!

The main difference between the two functional extremes of nuisance and foundation of the food web is the unique mixture of methods an individual biofilm will use to produce and use energy.

There are two main ways that biofilms can generate or consume energy: through oxygen-driven processes like photosynthesis, or chemical reactions which happen in areas lacking oxygen. These chemical reactions, mostly caused by bacteria or archaea, are essential sources of nutrients including nitrogen for freshwater ecosystems. 

Almost every biofilm will have a combination of these processes happening at the same time. Bacteria and archaea will generate chemical reactions that produce molecules needed by another member of the biofilm like diatoms (microscopic single-celled algae) in order to start photosynthesis. Therefore, each individual part of the biofilm contributes to a vast network of chemical reactions and energy exchanges that can enrich or maintain an entire ecosystem.

Biofilms can play any number of roles in a habitat. In desert ecosystems, biofilms act as anchors, using their sticky materials to bind sand grains together, which allows plants to start growing without being ripped from their positions by the strong winds. In rivers and streams, biofilms are major producers of energy for the whole food chain, and out in the ocean, biofilms are responsible for taking a great deal of nutrients and oxygen from the air and making them available in the water for other creatures to use. 

However, maybe most impressively, biofilms are the main producers of energy for areas that feature many ice sheets, like polar ice valleys and ice-covered lakes. Biofilms truly are fascinating forces of nature capable of sustaining an entire ecosystem, destroying structures, cleaning our water, fertilizing crops, and even causing cavities. So the next time you see a slimy film on a rock, thank your little biofilm friends for all their hard work!

References:

Barral-Fraga, L., Martiñá-Prieto, D., Barral, M. T., Morin, S., & Guasch, H. (2018). Mutual interaction between arsenic and biofilm in a mining impacted river. Science of The Total Environment, 636, 985–998. https://doi.org/10.1016/j.scitotenv.2018.04.287 

Bharti, A., Velmourougane, K., & Prasanna, R. (2017). Phototrophic biofilms: Diversity, ecology and applications. Journal of Applied Phycology, 29(6), 2729–2744. https://doi.org/10.1007/s10811-017-1172-9 

Romani, R. M., Guasch, H., Balaguer, M. D., & de Montilivi, C. (2016). Aquatic biofilms: Ecology, water quality and wastewater treatment (1st ed.). Caister Academic Press. 

Zijnge, V., van Leeuwen, M. B., Degener, J. E., Abbas, F., Thurnheer, T., Gmür, R., & M. Harmsen, H. J. (2010). Oral biofilm architecture on natural teeth. PLoS ONE, 5(2). https://doi.org/10.1371/journal.pone.0009321