Public Event for Metro Park: History, Science, and Clay Art!

This event is to mix three things that don’t necessarily go together. It is hands-on art creation while learning about the history of the Cherokee Tribe and anthropogenic disturbances that aquatic animals endure in streams. Integrating science, art, and history can help connect how all three are intertwined. This event is designed for questions to be asked during the talks for people who have questions about the topics. It is an open dialogue, not a lecture.

Itinerary:

Saturday/Sunday event (Be prepared to get in the water)

  • 2pm – Meet at the park facility.
    • Welcome to the park and talk about the itinerary.
    • Muck boots will be available if anyone needs/wants.
  • 2:15pm – Walk to creek.
    • Talk about the historical use of clay in Cherokee culture during the walk down.
  • 2:45pm – Collect clay from stream.
    • Baggies will be provided to put clay in.
  • 3:15pm – Walk back to facilities with clay.
    • Talk about animal physiology during walk back.
  • 3:45pm – Make clay sculptures!
    • Make any type of plant or animal you want! Be sure to apply water as you make it to keep it moist. Alternative option is to make a pot and carve an animal on the side. This should be a creative activity with no guidelines.
  • 4:30pm – Once everyone is happy with their creation we will place them in a designated spot to dry for two weeks. After two weeks, we will place them in the kiln for two hours.
  • After 2 weeks have the people come back to pick them up. If there is enough demand, there can be a follow up painting session.

Cherokee Talk: The Cherokee Tribe (a piece of my ancestry) were one of the first non-European groups to become U.S. citizens. Currently there are 3 tribes recognized by the U.S.: Cherokee Nation (NC), Eastern Band of Cherokee Indians (OK), and United Keetoowah Band of Cherokee Indians (OK). The Cherokee tribe used to use clay to make utilitarian, ceremonial, and decorative items including bowls, pipes, pots, water jugs, and more. They started using clay about 4500 years ago and created their first pots around 700BC. The first pottery made by a Cherokee was a woman who watched how wasps use the mud to make their home. The mud was fire-resistant and could hold water. It eventually became an art form and used as decoration. When we make our art with clay, we should remember how important it was for the indigenous populations that lived here before us.

Physiology Talk: Our infrastructure in the United States uses waste water treatment plants to clean our water before we pump it back into the rivers. This system allows us to have clean water for people downstream to use and it helps preserve the environment. The problem is that we aren’t filtering everything out of the water. There are chemicals that are left in the water because it takes too much effort to filter out. One type of chemical is an endocrine disruptor. An endocrine disruptor is a hormone mimic molecule. It replicates a natural hormone in our body and can be used to alter our body for better or worse. When people take estrogen supplements such as birth control, we don’t filter it all out of our system and it is excreted in our urine. That is sent to the waste water treatment plant and is not filtered out. These enter the water system and can cause problems on animals. One of the problems is that it can cause feminization in male animals. There was a study done on African clawed frogs that found what Atrazine, a common herbicide, can do to them (Hayes et al. 2010). The herbicide acts as an estrogen endocrine disruptor in some animals. Some of the males that were exposed to this herbicide were able to make their own eggs! When those males with eggs were paired with a normal male, they created 100% male offspring. Males exposed to estrogen mimic hormones also had more feminization characteristics such as their larynx (voice box), genitals, and less pronounced grip pads on feet used for clasping the female during mating. There are more studies on feminization in male animals from estrogen mimic hormones that enter the system through waste water treatment plants and agriculture practices. There are ways to filter out estrogen from the waste water treatment plant but it is an expensive process.

Hayes, T. B., V. Khoury, A. Narayan, M. Nazir, A. Park, T. Brown, L. Adame, E. Chan, D. Buchholz, T. Stueve, and S. Gallipeau. 2010. Atrazine induces complete feminization and chemical castration in male African clawed frogs (Xenopus laevis). Proceedings of the National Academy of Sciences of the United States of America 107:4612-4617.

After walking to the creek.

Find some clay.

Collect and put in bag.

Bring back to create art and use spray bottle to keep clay moist.

It can get messy…

Create an animal! This is a Logperch Darter (Percina caprodes)

It’s not perfect but I had fun!

What it’s supposed to look like.

Citations:

Cherokee information cited from: http://www.cherokeeheritage.org/wp-content/uploads/2013/08/CherokeePotteryCat.pdf

Hayes, T. B., V. Khoury, A. Narayan, M. Nazir, A. Park, T. Brown, L. Adame, E. Chan, D. Buchholz, T. Stueve, and S. Gallipeau. 2010. Atrazine induces complete feminization and chemical castration in male African clawed frogs (Xenopus laevis). Proceedings of the National Academy of Sciences of the United States of America 107:4612-4617.

Logperch Darter Image: http://johno.myiglou.com/fish/darters.html

Colors

Colors like these will disappear if global temperatures continue to rise. These salmon and trout skin colors are found in cold water streams fed by spring or snow melt water. With climate change affecting snowfall and increasing water temperatures, trout and salmon will not be able to live in these warmer conditions. There will be a shift of salmon and trout to move up in latitude due to temperatures increasing (Jonsson and Jonsson 2009). The reason these fish can’t stand warmer temperatures is because they have thermal limits just like we do. A thermal limit is when an animal reaches a certain temperature, they can’t function properly.

If we are cold, we shiver; if we are hot, we sweat. When fish get to hot they can’t sweat. They can move to colder water but most are limited on where they can move. If there is not a cooler place to move to, they will have to stop certain biological processes to focus on staying alive.

Two of these processes are growth and egg production. Fish are not like humans in the sense that they stop growing at a certain size. They will keep growing the more they eat. When conditions are too warm, they need more of their energy to process the excessive heat they are experiencing and limit their energy to grow or make more eggs. This results in smaller fish and fewer eggs (Neuheimer et al. 2011).

What can you do about this? Learning more about what causes climate change and how to prevent it. This can be done on an individual level that can affect small-scale local improvements. This can spread to friends and neighbors and ripple across communities. With time, our society can be more aware of climate change issues. Take action by contacting to political figures that govern regulations that affect climate change. Between individual actions and political leaders, we can help preserve these colors that inhabit our streams and rivers.

Literature Cited:

Jonsson B, Jonsson N. (2009) Dec. A review of the likely effects of climate change on anadromous atlantic salmon salmo salar and brown trout salmo trutta, with particular reference to water temperature and flow. Journal of Fish Biology 75(10):2381-2447. doi: 10.1111/j.1095-8649.2009.02380.x.

Neuheimer AB, Thresher RE, Lyle JM, Semmens JM. (2011) May. Tolerance limit for fish growth exceeded by warming waters. Nature Climate Change 1(2):110-113. doi: 10.1038/nclimate1084.

Images:

Image edited by Scott Glassmeyer – Top left: Brook Trout, Top right: Lake Trout, Bottom left: Rainbow Trout, Bottom right: Brown Trout.

Figure source: http://www.nature.com/scitable/knowledge/library/physiological-optima-and-critical-limits-45749376

Image source: http://animals.nationalgeographic.com/animals/fish/sockeye-salmon/

Fish in Drag

For more information on the podcast, Electrified Clay, visit electrifiedclay.wordpress.com

Works Cited

Adams SB (2011) Climate Change and Warmwater Aquatic Fauna. U.S. Department of Agriculture, Forest Service, Climate Change Resource Center. http://www.fs.fed.us/ccrc/topics/climate-change-and-warmwater-fauna

 

Aris AZ, Shamsuddin AS, Praveena SM (2014) Occurrence of 17α-ethynylestradiol (EE2) in the environment and effect on exposed biota: a review. Environ. Int. 69: 104−19.

 

Casas L, Saborido-Rey F, Ryu T, Michell C, Ravasi T, Irogoien X (2016) Sex change in Clownfish: Molecular insights from transciptome. Nature Scientific Reports 6:35461.

 

Esplugas S, Bila DM, Krause LGT, Dezotti M (2007) Ozonation and Advanced Oxidation Technologies to Remove Endocrine Disrupting Chemicals (EDCs) and Pharmaceuticals and Personal Care Products (PPCPs) in Water Effluents. J Hazard Mater 149(3): 631–642.

 

Frankel TE, Meye MT, Kolpin DW, Gillis AB, Alvares DA, Orlando EF (2016) Exposure to the contraceptive progestin, gestodene alters reproductive behavior, arrects egg deposition, and masculinizes development in the fathead minnow (Pimephales promelas). Enviornmental Science and Technology 50: 5991-5999.

 

Harris CA, Hamilton PB, Runnalls TJ, Vinciotti V, Henshaw A, Hodgson D, Coe TS, Jobling S, Tyler CR, Sumpter JP (2011) The consequences of feminization in reading groups of wild fish. Environmental Health Perspective 119:306-311.

 

Langley L (2013) 7 Gender Altering Animals. National Geographic. http://voices.nationalgeographic.com/2013/09/22/7-gender-bending-animals/

 

McKelvey KS, Perry RW, Mills LS (2013) The Effects of Climate Change on Mammals. U.S. Department of Agriculture, Forest Service, Climate Change Resource Center. www.fs.usda.gov/ccrc/topics/wildlife/mammals

 

National Geographic (2017) Anglerfish. http://animals.nationalgeographic.com/animals/fish/anglerfish/

 

Orlando EF, Ellestad LE (2014) Sources, concentrations, and exposure effects of environmental gestagens on fish and other aquatic wildlife with an emphasis on reproduction. Gen. Comp. Endocrinol. 203: 241−9.

 

Petitti DB (2003) Combination estrogen−progestin oral contraceptives. New England Journal of Medicine 349 (15): 1443−1450.

Introduction music and music at the end: Garage Band Presets

Listen to the Canaries

Global climate change poses numerous threats for species across the world—some of these challenges include rising temperatures and sea levels, changing habitats and landscapes, increased severe weather and unstable climate patterns (The Nature Conservatory, 2017). These issues don’t just affect humans—many species are also being forced to respond to this rapidly changing world. Certain species are more sensitive to the results of climate change, and they act as indicators of ecosystems health. Since birds are sensitive to change, they can act as an early warning to the detrimental effects of climate change (Lemoine et. al., 2005), alerting us to take action to address the underlying causes—if we listen.

So how exactly is climate change affecting birds? Birds are laying eggs earlier, migration patterns are changing or being lost entirely, bird behavior is changing, population ranges are shifting, and extinction of certain species is becoming increasingly common (Nature Canada, 2017). Each of these changes can have a significant effect on population health, and that short list doesn’t take into account that many of those changes are happening simultaneously. There are many examples of this found within scientific literature, but it is difficult to make generalizations about all bird populations because there are a vast number of species of birds. However, almost all bird species rely on precise timing of environmental cues for reproductive, developmental, and spatial distribution. There are precise times to try to attract mates, specific times when breeding should occur, along with times designated for migration preparation (in migratory birds), and all of these events (among others) require a certain synchronicity. These cycles are specifically regulated by hormones that are set in motion when birds integrate sensory information from their environment, so they know how to proceed. However, climate change is greatly affecting these crucially timed cycles, resulting in mis-matched patterns that birds depend on for breeding and mating (Carey, 2009). As a result, birds are being forced to physiologically respond to this changing landscape, mainly by shifting the timing of certain behaviors such as singing songs involved in mating (Nature Canada, 2017). It is important to note, though, that since climate change has many different outcomes, birds respond in many different ways – what affects one species may not affect another.

Unfortunately, timing isn’t the only aspect of bird physiology and behavior being affected. Rising temperatures associated with global climate change have huge effects on bird metabolism and energy requirements. Increase in temperature means an increase in bird metabolism, or energy needed to survive and reproduce. Each species has a specific optimal temperature range, and any change in environmental temperatures can cause huge amounts of stress on these organisms as they try to cope (Milne et. al., 2015). Couple that with changes to resource distribution (such as food and habitat), and things get complicated fast. Regardless of what kind of stressor is in the environment, in many cases, birds are some of the first species affected in an ecosystem (Hills, 2017).

In a changing world, bird populations can act as an indicator for overall ecosystem health because they are some of the first species affected (Stolen et. al., 2005), so when these populations begin to be negatively affected, we need to take action. Birds are excellent environmental indicators, because they can directly indicate habitat quality. Various studies have found that when bird habitat becomes fragmented or degraded, populations respond negatively physiologically and behaviorally in predictable ways (O’Connell et. al., 2000). Additionally, birds are very sensitive to environmental pollutants. This was seen in their response to DDT, a harmful pesticide, among other chemicals that devastated bird populations (Hill, 2017). Bird song has been used to detect safe air environments in the past, as well; have you ever heard of the saying “a canary in a coal mine”? This saying dates back to the early 1900s when coal miners would take canaries into coal mines. If these birds would stop singing, it acted as an early-indication that the mine was likely full of carbon monoxide or other toxic gases (Eschner, 2016). Similarly, to the canaries in the coal mine (hence the title), it is important to look to sensitive species in the environment as our planet continues to warm. They act as a clear indicator that something needs to be done to halt the effects of global warming to the best of our ability.

So how exactly can you help protect bird populations? Small changes, can make big differences, especially when it comes to ecosystem health. There are many things you can do to reduce your ecological footprint, which is just a fancy way of saying the impact you have on the environment. Investing in energy efficient appliances, carpooling or walking to your destination, or even something as simple as remembering to turn off your lights when you aren’t using them—all these things can help fight climate change (The Nature Conservatory, 2017). Additionally, to specifically help protect birds in the face of climate change, you can set up bird feeders (but be sure to keep your pets away!), avoid using harmful chemicals in and around your lawn, and plant native species in your yard to encourage native bird species to eat and nest there (Environment for the Americas, 2012). Another thing you can do is to participate in Citizen Science bird projects (The Cornell Lab of Ornithology, 2017). These projects are essentially to research, and provide critical information about the health of bird populations. Once we listen to the birds around us, we’ll realize there is so much on our planet that is worth protecting, and better yet, we’ll realize that there are so many things we can do to make a difference.

 

Works Cited

Carey C (2009) The impacts of cliamte change on the annual cycles of birds. Philos Trans R Soc Lond B Biol Sci 364:3321-3330.

Environment for the Americas (2012) 20 ways to conserve birds. http://www.birdday.org/birdday/themes/2012-twenty-years-of-imbd/20-ways-to-conserve-birds

Eschner J (2016) The story of the real canary in a coal mine. http://www.smithsonianmag.com/smart-news/story-real-canary-coal-mine-180961570/

Hill J (2017) Birds as environmental indicators. http://www.environmentalscience.org/birds-environmental-indicators

Lemoine N, Schaefer HC, Bohning-Gaese KB (2006) Species richness of migratory birds is influenced by global climate change. Global Ecology and Biogeography 16: 55-64.

Milne R, Cunningham SJ, Lee ATK, Smit B (2015) The role of thermal physiology in recent declines of birds in a biodiversity hotspot. Conerv Physiol 3: 1-17.

Nature Canada (2017) How is climate change affecting birds? http://naturecanada.ca/what-we-do/bird-conservation/climate-change-birds/

O’Connell TJ, Jackson LE, Brooks RP (2000) Bird guilds as indicators of ecological condition in the central Appalachians. Ecological Applications 10: 1706-1721.

Stolen ED, et al. (2005) Using waterbirds as indicators in estuarine systems: successes and perils. Estuarine Indicators 7: 409-422.

The Cornell Lab of Ornithology (2017) Mission: Conservation. http://www.birds.cornell.edu/page.aspx?pid=1666

The Nature Conservatory (2017) Climate change threats and Solutions. https://www.nature.org/ourinitiatives/urgentissues/global-warming-climate-change/threats-solutions/

Photo

Photo credit to Smithsonian (Eschner, 2016)

Bioaccumulation & Biomagnification: A Heavy (Metals) Topic

In 1962 Rachel Carson published what is now recognized as one of the most important books in conservation literature, Silent Spring. Based on original research conducted in response to reports linking an observed decline in bird populations with widespread use of DDT as a pesticide in the 1950’s, the book broadly asserted that liberal use of DDT was contributing to considerable detrimental impact on the environment through trophic interactions. Although the book was met with considerable opposition from the chemical industry and lobbyists at the time, the academic community, along with the general public, defended the work. The book also emboldened the environmentalist movement, and eventually resulted in a ban on DDT in 1972, following president Nixon’s creation of the Environmental Protection Agency (EPA).

Bioaccumulation is a phenomenon that occurs when chemicals or toxins build in the tissues of organisms over time. One of the key problems with DDT is that at low concentrations it appeared to be harmless to vertebrate organisms, while being lethal to common pest invertebrates such as mosquitoes and flies. Thus, the negative effects of DDT on larger organisms such as mammals and birds were not initially apparent. DDT is not easily broken down through the metabolic pathway, yet readily passes across the gastrointestinal barrier. Organisms that consume organic material containing DDT will therefore accumulate the chemical in their fat stores, until eventually concentrations become lethal. However, such compounds can also be “passed up” the food chain in a process known as biomagnification. Insects such as mosquitoes that die from DDT exposure may find their way into water, where they are consumed by fish. Those fish then sequester the chemical in their tissues, and may then be consumed by larger predators such as eagles, osprey and falcons (Carson, 1962).

Although DDT has been banned for use in the U.S. except for in emergency situations, there are a number of other chemicals and compounds that have been known to bioaccumulate and biomagnify. Heavy metals such as mercury (Hg) are highly toxic to most living organisms. In particular, mercury causes permanent damage to a class of molecules called thioredoxin reductases (Carvalho, et. al., 2008), enzymes that are essential for proper cell growth and in counteracting oxidative damage from metabolic activity (Linster & Van Schaftingen, 2007). In an ecosystem-level study in Connecticut, it was shown that increases in mercury concentrations of fish were correlated with body size and age. Additionally, predators occupying the top of the food chain accumulated mercury the fastest, regardless of species identity (Neumann & Ward, 1999). Similar patterns of bioaccumulation and biomagnification have been observed in sharks in marine ecosystems (Maz-Corrau, et al., 2012), as well as montane stream ecosystems (Chasar, et al., 2009).

However, bioaccumulation of pollutants in aquatic ecosystems may have potentially devastating consequences for non-aquatic organisms as well. In particular, fish-eating sea birds are very susceptible to poisoning from industrial pollutants, as some compounds such as polychlorinated biphenyls (PCBs) are remarkably persistent in tissues (Walker, 1990). In a study conducted  at Kesterson Reservoir in California, bioaccumulation of selenium (Se) was observed in several species of birds, and correlated with reductions in adult body weight, and embryonic mortality (Ohlendorf, et al., 1990).

But bioaccumulation doesn’t just stop at birds and fish. Contamination of fisheries with metabolically stable compounds and chemicals has been reported across the globe, from Romania (Bravo, et. al., 2010) to China (Feng, et al., 2007). Even in the United States there is mounting concern that deposition of atmospheric heavy metals from industrial manufacturing and coal-fired power plants can reach fisheries via hydrologic processes such as runoff, and eventually affect human health (Driscoll, et al., 2007). After all, humankind has in many ways found its way to the top of the global food chain. So while the effects of bioaccumulation may seem a distant or alien concern in our isolated human ecosystem, it may not be long before heavy metals make their way onto our dinner plate.

Sources:

Bravo, A. G., Loizeau, J. L., Bouchet, S., Richard, A., Rubin, J. F., Ungureanu, V. G., … & Dominik, J. (2010). Mercury human exposure through fish consumption in a reservoir contaminated by a chlor-alkali plant: Babeni reservoir (Romania). Environmental Science and Pollution Research, 17(8), 1422-1432.

Carson, R. (1962). Silent spring. Houghton Mifflin Harcourt.

Carvalho CM, Chew EH, Hashemy SI, Lu J, Holmgren A (2008). “Inhibition of the human thioredoxin system: A molecular mechanism of mercury toxicity.”. Journal of Biological Chemistry. 283 (18): 11913–11923.

Chasar, L. C., Scudder, B. C., Stewart, A. R., Bell, A. H., & Aiken, G. R. (2009). Mercury cycling in stream ecosystems. 3. Trophic dynamics and methylmercury bioaccumulation. Environmental science & technology, 43(8), 2733-2739.

Driscoll, C. T., Han, Y. J., Chen, C. Y., Evers, D. C., Lambert, K. F., Holsen, T. M., … & Munson, R. K. (2007). Mercury contamination in forest and freshwater ecosystems in the northeastern United States. BioScience, 57(1), 17-28.

Feng, X., Li, P., Qiu, G., Wang, S., Li, G., Shang, L., … & Fu, X. (2007). Human exposure to methylmercury through rice intake in mercury mining areas, guizhou province, china. Environmental science & technology, 42(1), 326-332.

Linster, C.L.; Van Schaftingen, E. (2007). “Vitamin C: Biosynthesis, recycling and degradation in mammals.”. FEBS Journal. 274 (1): 1–22.

Maz-Courrau, A., López-Vera, C., Galvan-Magaña, F., Escobar-Sánchez, O., Rosíles-Martínez, R., & Sanjuán-Muñoz, A. (2012). Bioaccumulation and biomagnification of total mercury in four exploited shark species in the Baja California Peninsula, Mexico. Bulletin of Environmental Contamination and Toxicology, 88(2), 129-134.

Neumann, R. M., & Ward, S. M. (1999). Bioaccumulation and biomagnification of mercury in two warmwater fish communities. Journal of Freshwater Ecology, 14(4), 487-497.

Ohlendorf, H. M., Hothem, R. L., Bunck, C. M., & Marois, K. C. (1990). Bioaccumulation of selenium in birds at Kesterson Reservoir, California. Archives of Environmental Contamination and Toxicology, 19(4), 495-507.

Walker, C. H. (1990). Persistent pollutants in fish-eating sea birds—bioaccumulation, metabolism and effects. Aquatic Toxicology, 17(4), 293-324.

 

Images (In Order of Appearance):

1st edition copy of Rachel  Carson’s Silent Spring. (https://thebreakthrough.org/archive/silent_spring_environmentalism_and_fear)

Illustration of the process of bioaccumulation and biomagnification. World Wildlife Fund. (http://sustainable-nano.com/2013/12/17/the-cautionary-tale-of-ddt-biomagnification-bioaccumulation-and-research-motivation/)

American Coot, one of the many species detrimentally impacted by bioaccumulation of selenium (https://www.allaboutbirds.org/guide/American_Coot/id)

Coal fired power plant. Shutterstock. (https://thinkprogress.org/7-out-of-10-americans-want-their-states-to-comply-with-the-epas-climate-plan-8ad8f9fe8e74)

 

Plastic Power!

Song produced and performed by Lewis Lolya (lyrics and music adapted from Damon Albarn and Jamie Hewlett)

Lyrics

I’m a seabird nesting on an isle
that you stained with plastic power
Your precious merchandise from factories far away

When the chemical dreams that we all seem to keep
drift on beaches where we sleep
our heart is beating in factories far away

So, call the colony from the beach
Our wings are all washed up in bleach
the waves are crying polyethylene tears
And nobody knows where to go from the heat
with plastic slicing up our feet, the seas are rising for this time of year

I got a feeling now my heart is broken
All these eats that I have chosen
rumbling in my stomach and in my soul
I pray, my wings are unmovable
Yeah clinging to this ocean shoal
Seasons seas, the adjustments, fateful change
I can’t see now my eyes are hazy
have you been out to my beach lately
The storms wash strange things beneath our feet

I’m a seabird nesting on an isle
That you stained with plastic power
Your precious merchandise from factories far away

Albatross fly over the beach
Same time every day, same routine
Clear eyes in the summer, their skies are blue
but It’s part of the noise when plastic comes
It reverberates in their lungs
Nature’s corrupted in factories far away

The seas are rising for this time of hear

Our hearts are beating in factories far away    X2

 

Lyrics Meaning 

Even the most remote corners of the world are not spared by the human footprint. One would think that a place like Midway Atoll or Laysan Island, hundreds of miles from the nearest human civilization, would be unspoiled paradises. These islands are home to vast colonies of seabirds of several amazing species. Some of the longest lived birds, the Albatross, call these islands home. Naturally free from predators, they certainly were what one would consider a paradise. But if one steps foot on these island, you may be in for a stomach churning surprise.

The pacific ocean garbage patch, a vast cyclone of plastic and discarded human products, swirls like a fantastic polyethylene sea-monster. This conglomeration of garbage, larger than the size of Texas,  is one of the most visually striking examples of the pollution we tend to ignore, but excessively create. Much of the garbage we throw away ends up in our oceans, where the currents and tides carry it to far away lands. Although the islands of Midway and Laysan are seemingly untouchable by the human hand, they have ended up being the poster child for the often unseen effects of plastic pollution. Like many other similar pacific islands and beaches, plastics of different shapes, colors and varieties festoon the once-pure sand. Certainly, the plastic debris have made these landscapes visually unappealing. However, some of the more insidious problems occur when wildlife and plastic pollution meet face to face. Seabird and many other forms of marine life ingest plastics found on beaches and in the ocean. Many confuse these oddly shaped plastics for natural food, or simply ingest them incidentally. Seabirds in particular, like the long lived albatross, are facing the worst effects from the ingestion of oceanic plastics (Pettit et al., 1981)

Ingestion of plastics can harm seabirds in several ways (Azzarello & Van Vleet, 1987). The most common cause of death by ingested plastics is the physical blockage of sections of the digestive system. Obstructions can usually occur in the intestines and the proventricular pathway. Often, Procellariforms are unable to regurgitate accidentally ingested plastics because their gizzard size is too small. Therefore, plastics can accumulate for long periods of time until digestive function slows or ceases.  Post mortem analysis of seabirds that died of plastic ingestion reveal that many had lacerations on the lining on several parts or their digestive system. Furthermore, the presence of non-food items in the gizzard and stomach of birds may lower their hormonal ability to regulate their hunger sensation and feeding activity levels (Sturkie, 1965). Stimuli processed by the central nervous system relay signals to the hypothalamus gland, which in turn control the hunger and feeding activity response in birds. The muscular contractions of an empty stomach are one of the main triggers for hormonal hunger control. When large quantities of plastic stay in the stomach, the sensation of fullness prevents the hypothalamus from initiating a feeding response. The birds end up starving themselves on a complete and balanced diet of plastic (Sturkie, 1965)

Plastic does get partially digested when stored in the stomach for a long duration (Peakall, 1970). Harmful trace chemicals such as DDT, DDE, and PCB’s, which are known endocrine disruptors, will be absorbed by the gastrointestinal system of the bird. Some effects of this include delayed ovulation, impaired reproductive success, and lowered sex steroid levels (Peakall  1970). Tanaka et al., (2013) analyzed polybrominated diphenyl ethers (PBDEs) in the stomach adipose tissues of some seabird species. The researches found significantly higher concentration of these chemicals than normal, which suggests that plastic chemicals are getting synthesized into the body tissues from ingested plastics particles, which may lead to many physiological impairments.

Several other adverse effects exist in seabirds that ingest large quantities of plastics. The fat content of migratory phalaropes decreased with the relative presence of plastic particles in the digestive tract, suggesting inhibition of proper nutrition. For migratory birds, the inability to refuel properly can be devastating; lowering survivorship, flight range capabilities, and breeding success rates (Connors & Smith, 1982). Even remote areas far from the source of these plastics are sometimes seeing the worst effects of plastic pollution.

 

What can you do?

There are simple ways that you can help reduce the impact of plastics on the environment. Reduce, reuse, and recycle all materials that you make or purchase. Opt for utilizing biodegradable containers or no packaging materials at all. Avoid purchasing items that are packaged in multiple layers of plastics. Many of the plastic bags and packaging that is malleable is non-recyclable and provides little in the way of alternative uses. However, what do we do with the plastics already in our environment? Several companies and engineers have developed methods of removing large quantities of plastics from out oceans. Methods like ocean rakes and ocean vacuums are being tested in polluted areas. On a large scale, these techniques can have a huge impact on cleaning our oceans and saving our seabirds.

Long live the albatross!

 

Literature Cited

Auman HJ, Ludwig JP, Giesy JP, Colborn TH. (1997) Plastic ingestion by Laysan albatross chicks on Sand Island, Midway Atoll, in 1994 and 1995. Albatross biology and conservation. 239244.

Azzarello MY, Van Vleet ES. (1987) Marine birds and plastic pollution. Marine Ecology Progress Series. 37:295-303.

Connors PG, Smith KG. (1982) Oceanic plastic particle pollution: suspected effect on fat deposition in red phalaropes. Marine Pollution Bulletin. 13(1):18-20.

Peakall DB. (1970) p, p’-DDT: Effect on calcium metabolism and concentration of estradiol in the blood. Science. 168(3931):592-4.

Pettit TN, Grant GS, Whittow GC. (1981) Ingestion of plastics by Laysan albatross. The Auk. 98(4):839-41.

Sturkie PD, editor. (2002) Avian physiology. Springer Science & Business Media

Tanaka K, Takada H, Yamashita R, Mizukawa K, Fukuwaka MA, Watanuki Y (2013) Accumulation of plastic-derived chemicals in tissues of seabirds ingesting marine plastics. Marine Pollution Bulletin. 69(1):219-22.

 

Photo Credit (in order of appearance)

Tristan Savatier

Kim Starr

Frans Lanting

Jeff Dunst

The scientific fisherman

Frans Lanting

Chris Jordan

Serje Takao

 

 

 

Coyotes in Columbus

One of my favorite courses at Ohio State University (OSU) is the mammalogy course offered in the School of Environment and Natural Resources, which is instructed by Dr. Stan Gehrt. A big part of this course is a field study, where students use different sampling techniques to survey wildlife around Columbus. Our group chose to survey mammals in Chadwick Arboretum, which is located on OSU’s west campus. In addition to daytime in-person surveys, our group set up camera traps in an effort to capture the area’s nightlife. We were mostly expecting to capture images of deer, and maybe raccoons, so you can imagine our surprise when a coyote showed up in our photos (Figure 1)!

Figure 1. Camera trap photo of a coyote in Chadwick Arboretum (my own)

Urban coyotes are far more common than some people realize, and research groups in urban centers around the country have studied this phenomenon. For example, Dr. Gehrt’s lab studies urban coyotes in Chicago, Illinois. Additional research efforts include the Urban Coyote Initiative and the Denver Urban Coyote Project (See the links below for more information on these projects!).

Not surprisingly, not all animals can thrive in the urban landscape. Urban environments can cause stress in animals (Schell et al., 2013; Birnie-Gauvin et al., 2016). When an animal becomes stressed, stored energy in its body is mobilized (Randall et al., 2001). This energy fuels the animal’s “fight or flight” response. This stress response allows the animal to deal with the stressor, which is beneficial in the short term. However, long-term stress can have negative health impacts, such as decreased functioning of the immune system, that result in decreased fitness (Randall et al., 2001).

When faced with anthropogenic disturbance, coyotes do present a stress response (Schell et al., 2013). However, research has shown that coyotes thrive in urban environments (Morey et al., 2007; Gehrt et al., 2011). This success in urban environments may be due, in part, to increased survival (Gehrt et al., 2011; Rodewald & Gehrt, 2014). Although adult coyotes have similar survival rates in urban and rural environments, research has shown that juvenile coyotes have higher survival rates in urban environments (Gehrt et al., 2011).

In addition to changes in reproduction and survival, urban species often behave differently than their rural counterparts (Ditchkoff et al., 2006; George & Crooks, 2006). For example, research has shown that coyotes have lower activity levels in areas where human activity is high (George & Crooks, 2006). Other species, such as bobcats, may become more nocturnal in urban areas in order to avoid high human activity during the day (George & Crooks, 2006). Urban species may also change their diets and foraging strategies in order to take advantage of food sources such as garbage or garden fruits and vegetables (Ditchkoff et al., 2006). These behavioral modifications help urban species to take advantage of new resources and avoid human-induced stress, which ultimately enables them to survive, and sometimes even thrive, in urban environments.

Check out the following links for more information:

References

Birnie-Gauvin K, Peiman KS, Gallagher AJ, de Bruijn R, Cooke SJ (2016) Sublethal consequences of urban life for wild vertebrates. Environ Rev 24: 416 – 425.

Gehrt SD, Brown JL, Anchor C (2011) Is the urban coyote a misanthropic synanthrope? The case from Chicago. Cities Environ 4.

Morey PS, Gese EM, Gehrt SD (2007) Spatial and temporal variation in the diet of coyotes in the Chicago metropolitan area. Am Midl Nat 158: 147 – 161.

Randall D, Burggren W, French K (2001) Eckert Animal Physiology: Mechanisms and Adaptations. W. H. Freeman and Company, New York.

Rodewald AD, Gehrt SD (2014) Wildlife Population Dynamics in Urban Landscapes. In: McCleery RA, Moorman CE, Peterson MN, eds. Urban Wildlife Conservation. Springer US, pp 117 – 147.

Schell CJ, Young JK, Lonsdorf EV, Santymire RM (2013) Anthropogenic and physiologically induced stress responses in captive coyotes. J Mammal 94: 1131 – 1140.

The True Sixth Sense: Electroreception

Electroreception is the biological ability to perceive natural electrical stimuli. In simpler words, it’s an animal’s ability to perceive the world via electricity. There are two forms of electroreception, active and passive. In active electroreception, the animal senses its surrounding environment by generating electric fields and detecting distortions in these fields using electroreceptor organs. This electric field is generated by means of a specialized electric organ consisting of modified muscle or nerves. In passive electroreception, the animal senses the weak bioelectric fields generated by other animals and uses it to locate them. These electric fields are generated by all animals due to the activity of their nerves and muscles.

Electroreception is quite common among aquatic or amphibious animals, considering water is a much more effective conductor than air. Some examples include sharks, rays, and the electric eel.

But what about mammals?

With recent estimates stating that there are nearly 5400 mammalian species, there has to be a few species possessing this ability, right? A few there are indeed! From what we know, the only mammals that possess the ability of electroreception are the platypus (Ornithorhynchus anatinus), echidnas (Tachyglossidae), and the Guiana dolphin (Sotalia guianensis).

Platypus & Echidnas (Monotremes)

Monotremes are very bizarre animals. They are mammals and yet, they lay eggs! The only surviving monotremes today are the platypus and four different species of echidnas. These momotremes possess the sixth sense of electrorecption!

Between the two, the duck-billed platypus by far has the most acute electrical sense. The platypus has about 40,000 electroreceptors striped along it’s bill. This allows it to catch large amounts of prey in the murky water at night. They swim with their eyes, ears, and nostrils closed, making electroreception a very useful trait.

Guiana dolphin

Although aquatic, this mammal was just recently discovered to also have electroreceptors and can sense electrical fields. On the snout of the dolphin, there are rows of little holes called hairless vibrissal crypts. Inside these crypts the dolphins have electroreceptors, capable of electroreception as low as to detect small fish.

There definitely may be more aquatic mammals that have this amazing ability, yet they have yet to be discovered.

Downfalls?

Although electroreception is an amazing ability, electrofishing may have deleterious consequences. Higher amounts of electroreceptors lower these mammal’s electrical impedance and make them vulnerable to the intense current generated by electrofishing devices. Direct observations show that these mammals were immobilized in the vicinity of the probe. This stressor, which makes these species particularly vulnerable, often causes death within hours of capture without rescue. It is important that we, as humans, are attentive when entering the homes of these mammals.

References:
Czech-Damal, N. U., Liebschner, A., Miersch, L., Klauer, G., Hanke, F. D., Marshall, C., Dehnhardt, G., & Hanke, W. 2012. Electroreception in the Guiana dolphin (Sotalia guianensis). Proceedings. Biological sciences / The Royal Society, 279 (1729), 663-8.

Pettigrew, J. D. 1999. Electroreception in monotremes. The Journal of experimental biology, 202, 1447-1454.

Scheich, H., Langner, G., Tidemann, C., Coles, R., & Guppy, A. 1986. Electroreception and electrolocation in platypus Nature, 319 (6052), 401-402.

Photo Credit:
Joel Sartore, National Geographic.

Manger, P.R. and Pettigrew, J.D., 1995. Electroreception and the feeding behaviour of platypus (Ornithorhynchus anatinus: Monotremata: Mammalia). Philosophical Transactions of the Royal Society B: Biological Sciences, 347(1322), 359-381.

Marcos Santos, WDC

“Cutbow” Trout: Sportfish Hybridization Increases with Climate Change

Rainbow Trout are a popular sportfish in the United States. The species has been stocked in lakes and streams outside of its native range since the late 1800s. Interestingly, in many areas where stocking has stopped, Rainbow Trout populations continue to thrive. This is because stocked Rainbow Trout have been able to survive and reproduce in their introduced ranges (Muhfeld et al., 2017). Over time, these stocked individuals and their offspring have immigrated out from the stocked locations and colonized new habitats. Rainbow Trout populations are now established across much of the United States, and the species is considered invasive in many areas.

Rainbow Trout populations are negatively impacting native trout species in these systems. This is because Rainbow Trout can hybridize with other closely related trout species. Hybridization occurs when two separate species reproduce. Hybridization between a native and invasive species can be dangerous. Native species are usually adapted to their habitat. However, invasive species often do not have the same set of adaptations. Thus, when a native and non-native species hybridize, some of the beneficial traits of the native species are lost or diluted by traits from the invasive species.

A team of researchers and USGS scientists have been studying this phenomenon in trout populations in the Northern Rocky Mountains since the 1980s (Muhfeld et al., 2017). Specifically, the team is interested in “Cutbow” Trout, which are produced when native Cutthroat Trout and invasive Rainbow Trout reproduce (Figure 1). Cutbow Trout are generally fertile, which means they can produce offspring of their own. This is an issue because as hybrids reproduce, the gene pool continues to get polluted.

Figure 1. Hybridization between native Cutthroat Trout and invasive Rainbow Trout produces “Cutbow” Trout.

Scientists expect climate change to favor Rainbow Trout, which will result in more hybridization between the invasive and native trout species (Bear et al., 2007; Muhfeld et al., 2014; Muhfeld et al., 2017). All species have a range of temperatures that they can live comfortably in (Randall et al., 2001). This range varies within and between species. At temperatures above or below this range, individuals experience decreased performance. Climate change results in warmer temperatures, which Rainbow Trout can tolerate better than Cutthroat Trout (Bear et al., 2007). In addition, Rainbow Trout have a higher capacity for growth at higher temperatures than native Cutthroat Trout (Bear et al., 2007). As waters continue to warm, Rainbow Trout are expected to continue to spread into new areas. Rainbow Trout will encounter more native trout populations in these areas, which will result in more hybrid trout populations (and continued decline of native trout populations).

Fortunately, invasive Rainbow Trout populations are being managed in several ways (Muhfeld et al., 2017). For example, barriers are often installed so that Rainbow Trout cannot reach uninvaded areas. Additional management strategies include habitat restoration and protection and fishing efforts targeting the invasive Rainbow Trout. These efforts will be critical for biodiversity conservation, especially in the face of climate change (Muhfeld et al., 2017).

 

Check out the following links for more information:

 

Figure created with images attributed to the National Park Service (http://www.yellowstone.co/fish.htm#wscut)

 

References

Bear EA, McMahon TE (2007) Comparative thermal requirements of westslope cutthroat trout and rainbow trout: implications for species interactions and development of thermal protection standards. Trans Am Fish Soc 136: 1113 – 1121.

Muhfeld CC, Kovach RP, Al-Chokhachy R, Amish SJ, Kershner JL, Leary RF, Lowe WH, Luikart G, Matson P, Schmetterling DA, Shepard BB, Westley PAH, Whited D, Whiteley A, Allendorf FW (2017) Legacy introductions and climatic variation explain spatiotemporal patterns of invasive hybridization in a native trout. Glob Change Biol.

Muhfeld CC, Kovach RP, Jones LA, Al-Chokhachy R, Boyer MC, Leary RF, Lowe WH, Luikart G, Allendorf FW (2014) Invasive hybridization in a threatened species is accelerated by climate change. Nat Clim Change 4: 620 – 624.

Randall D, Burggren W, French K (2001) Eckert Animal Physiology: Mechanisms and Adaptations. W. H. Freeman and Company, New York.