UES 150 Fall 2020

I have never heard of a “Zebra mussel” before I read this article. The Zebra mussel is the invasive species that caught my attention because of the immense destruction that it has caused. I was amazed by the deficits on the economy that this species has created. I couldn’t fathom that a mussel could create and cause this much turbulence.  The zebra mussel is a thumbnail size mollusk native to the Black Sea that showed up in Lake St. Clair, Ontario, in 1988, Zebra mussels like to attach themselves to a hard surface, and they don’t mind a crowd. Sometimes these mussels will stack on top of each other as dense as 70,000 individual mussels per square foot. I try to picture this in my mind it amazes me how they can fit so many is such a small area of surface. The article assigned stated that within two years these mussels were in the shallows of the Great Lakes. This took a significant tole on surrounding business owners. These mussels will get into pipes, ships’ rudders were jammed. Between the U.S. and Canada lose about 140 million dollars a year in direct result of these mussels. 

            Zebra mussels negatively impact ecosystems in many different ways. First, they filter out algae that native species need for food and they attach to—and incapacitate—native mussels. Power Plants must also spend millions of dollars removing Zebra mussels from clogged water intakes. There are many current studies going on to better understand its behavior and biology. They have not figured out a solution to prevent and/or control the population of zebra mussels. 

            There is not a way to eradicate this species yet. There was a documented attempt in Virginia about 12 years ago in a private pond/lake of multiple acres and was successful. They converted it into a saltwater quarry by adding salt. However, there was no outlet to contaminate any rivers. Daniel Molloy, a research scientist at the State University of New York at Albany, created a bacterium that gave way to an environmentally safe pesticide called Zequanox. However, The EPA prohibits treatment of Zeaquanox in open water and “unconfined infrastructure”. This limits this product to very few customers that are legally and efficiently allowed to use this product. Hopefully this will give scientists ideas to innovation to be able to create a product that has lots of potential to help preserve native species and make a good living out of it. 

There are many different species that are predators to the zebra mussel. The pumpkinseed sunfish, freshwater drums, redhorse sucker, river carpsuckers, smallmouth buffalos, and diving ducks are some of the many different species that feed on these terrible invasive mussels. Although there is predation that seems to not have been very effective when trying to control the zebra mussel population. 

The invasive species I chose is called Mikania micrantha, or more commonly known as “Mile-a-Minute” or “Chinese creeper.” It’s a perennial vine meaning once it roots, it will stick around for years. Perennials can withstand seasonal changes, and if they become dormant in cold weather, will revive in the springtime. Mikania micrantha originated in Southeast Asia and the Pacific where it has massively invaded tea and coconut plantations, in some cases causing complete plantation abandonment in these areas. Interestingly enough, it was used in WWII as a camouflage for airfields in India. It was first discovered in the United States in Florida where it has since grossly invaded the state but also spread throughout the country. It thrives in moist areas with high precipitation, hence why it has done so well in the state of Florida where the humidity is often 80% or higher. Mikania micrantha is actually named one of the world’s 100 most invasive species. It spreads similarly to a dandelion in that its flowers dry up, revealing feathery seeds that can be easily carried through the wind. A singular origin of this vine can produce up to 40,000 seeds per year. These numerous seeds can spread very quickly in the wind or carried in the fur of animals and once they arrive, they are difficult to get rid of due to their invasive nature. In addition to its easily-transferable seeds, Mikania micranthia grows at an impressive rate, making it even more difficult to eradicate. This is especially troublesome when considering the types of plants Mikrania micrantha threatens. It often threatens fruiting plants such as banana, cacao, and coconut plants by smothering them out with their rapid growth. The vine blocks light from reaching these plants, inhibiting photosynthesis, and slowly killing the plant. In some cases, this vine has even been known to creep into rice plantations and slowly smother the crop. The following suspicion is not confirmed, but it is believed that this vine releases a chemical that further harms plants in which it grows upon. This vine doesn’t just threaten these plants. It threatens a multitude of produce that feeds America and stimulates the economy. This is why it is so important that we are able to keep this “Mile-a-Minute” under control.

As you can imagine, Mikrania micrantha is extremely difficult to eradicate. A few experimental fungal pathogens and bugs have been introduced to this vine in an effort to pinpoint a strong natural enemy. It appears, however, that no clear or solid solution has been identified. A straightforward method of removal is manual cutting the vines and stripping the area of all traces of the vine. This will help the issue in the short term in that light will again be able to reach the plants it was previously surrounding. However, this vine will quickly reproduce from the remaining seeds and/or from any small fragments left behind. Chemicals will also help eradicate this invasive vine with the risk of infecting the produce plants surrounding. In summary, there is no clear-cut method yet on the removal of Mikrania micrantha. It will likely continue to be one of the prevalent invasive species in the world until new information or new technology is discovered.

https://www.fdacs.gov/Agriculture-Industry/Pests-and-Diseases/Plant-Pests-and-Diseases/Mikania-Micrantha-Mile-a-Minute

http://www.iucngisd.org/gisd/species.php?sc=42

I chose to research The Burmese python for my invasive species. They are non venomous and are constrictors so they squeeze their prey to death instead of injecting them with venom. The Burmese Python can get up to 23 feet in length and become as dense as a telephone pole, weighing up to 200 pounds. Making them the second largest snake behind the Green Anaconda. They’re native to South and Southeast Asia but can be found in the Florida everglades due to the rise of interest in the exotic pets. Their natural habitats are swampy jungles so the everglades are a perfect match for the Burmese Python. According to fox news there are an estimated 100,000 pythons in the everglades. This could be attributed to the large boom of popularity the python had in the 1980’s.They have been imported as pets but have been released into the wild due to how large and unmanageable they become. Some experts believe that a large number of snakes were released into the wild after hurricane Andrew, a category 5 hurricane, destroyed a python breeding facility releasing thousands of snakes into the swamp. Releasing them into the wild has effected the ecosystems heavily because they have no natural predator, making them the apex predator in the everglades. This has caused a large decline in the mammal, birds, and even reptiles population. The Flordia wildlife confederation encourages people to remove and hunt pythons on private property when ever spotted. They need help from the public in eradicating the invasive species because they are very hard to spot due to their camouflaged skin.

Burmese pythons are the species that I decided to choose for this discussion. Growing up in Florida it has been a very real thing for me when traveling down to the Everglades/Miami area of hearing stories about these giant snakes. The Burmese python is one of the largest snakes that slithers the earth today. Some fan grow 20 plus feet and are known to first originated in South East Asia but now have made there way to the Florida Everglades. An on going controversy with the Burmese python is how exotic pet owners are the reason that they are in the United States today. Many pythons were either kept as pets by people or brought over to be sold in the United States. One major key to the pythons survival in Florida is the weather conditions. South Florida’s climate and heat is a prestige and ideal place for the Burmese python to thrive. The fish and wild life services as well as a variety of other services that you may have seen on reality tv have pledged to get rid of or limit the python population in Florida. Many people have had pythons in their own back yards or houses in south Florida making for a terrifying experience. The Burmese python has shocked Florida’s ecosystem and habitat as a now huge predator roams south Florida that was not there prior. Many people fear for there safety as well as pets such as dogs etc. Pythons tends to attack smaller mammals such as household pets or possums etc rather than a human in most cases. One problem of the continuing growth of Burmese pythons is that they are constantly breeding. Many fish’s and wild life rangers as well as civilians have found loads of python eggs in various locations. Pythons have even been known to eat objects as large as full grown deer so the threat to humans is still very real. Bases on an article I researched I read that the Burmese python has caused over 100 billion dollars in damages just in the United States alone. If a 20 foot slithering snake doesn’t scare you I’m sure that amount of money lost will. Burmese pythons have became such a problem in the everglades and south Florida area that there is now a hotline for people to use who see or think they have seen an invasive python. Even though some pythons can grow up to 20 feet. The average python caught in Florida is a round 8-9 feet which is still huge! Weighing over 200 pounds sometimes they can be a struggle to catch or capture. Burmese pythons are huge in weight but lack in the ability to obtain stamina. This really isn’t that big of a deal because they use their brain to stalk their prey before making a move. Out of the incidents that have happened with him and it is usually when they are sleep or not paying attention. All Burmese python incidents with humans have been with their owners or the family of the owners associated with the snake. As the problems continue to grow for people in south Florida dealing with Burmese problems, hopefully the solutions will as well. Fish and wild life as well as many other organizations are working hard to figure out what they can do to stop this invasive species. 

Coqui Tree Frogs are native to Puerto Rico and were accidentally introduced to Hawaii because these frogs were hiding in a shipment of plants to the island. These frogs are very small (smaller than 2.5 cm) and have a rounder body shape that are found on the ground level of different trees and bushes. These tree frogs have no natural predators and no competitors meaning this particular tree frog’s population is not in check and therefore has skyrocketed Hawaii’s numbers above Puerto Rico’s numbers. This frog eats a lot of insects which takes food away from other species, and takes away insects who are valuable in the pollination process. The only potential predators for these frogs would be snakes if they were to arrive on the islands of Hawaii that these frogs invaded. Coqui tree frogs have very loud voices that are around 90 decibals, and breeding males co-KEE all night long trying to summon a mate. These frogs have decreased the property value in Hawaii and failure to report one of these frogs on your property when you sell it can lead to getting sued. On the subject of the economy, tourism is hurting in Hawaii because of these particular frogs.

The National Wildlife Federation describes the Puerto Rican coqui as “a small arboreal frog that’s brown, yellow, or green in color and does not have webbed feet.” Because the coqui do not have webbed feet, they cannot swim like other frogs, but these frogs can climb. This article gives more information about their native range. They are originally from Puerto Rico and have been introduced to the U.S. Virgin Islands, Hawaii, Florida greenhouses, and in some Louisiana greenhouses. In the Virgin Islands, they live peacefully, but everywhere else they are considered an invasive species or a "pest". The coqui frogs spend their nights in the trees and then retreat to the ground level of the forests right before morning. Something interesting the National Wildlife Federation points out is the reproduction and growth process. These frogs do not have a tadpole stage. Because of this, their tails emerge from the eggs. The National Wildlife Federation also mentions how the father of the eggs stays with them for a couple of days after hatching to protect them from potential predators as well as keeping them from drying out.

https://www.nwf.org/Educational-Resources/Wildlife-Guide/Amphibians/Puerto-Rican-Coqui

https://mauiinvasive.org/coqui-frog/

https://www.orlandosentinel.com/news/os-xpm-2006-09-15-coquis15-story.html#:~:text=Unlike%20other%20frogs%2C%20coqui%20don,to%20the%20island's%20urban%20areas.

Coqui tree frogs are native to Puerto Rico’s rainforests and got their names from the noise that they make that literally sounds out their name, Co-qui. They are tiny, only growing to 1 to 2 inches in length and 2 to 4 ounces in weight, yet the noise that they make can reach a deafening 90 decibels. The noise that they make is designed to attract mates and their scientific name translated means free toes because they do not have webbed feet.

These frogs travel very short distances, however, can be transported great distances. They can infest nurseries for plants and flowers that are being exported to other countries. One of the main areas that the frog has infested is Hawaii. Hawaii is struggling with property devalue issues because the noise of the frogs is disruptive to visitors and people that are investing in Hawaiian properties. They have traveled by way of plants and human travel to specific islands of Hawaii. Maui, Kaua’i, and O’ahu are infested with this invasive species, while Moloka’i and Lana’i currently do not have these frogs on the island.

The characteristics that make it so successful are the size of the frogs and the fact that there are absolutely no natural predators. It is surprising that no one species in the life-filled rainforests for such a small amphibian. Another aspect is that they have no native competition for food sources or habitual tendency.

Since there are no predators or competition, Coqui frogs are free to roam and thrive with no consequence. They disrupt the balance of native ecosystems by the sheer number of insects that they are able to feast upon. They kill extremely large quantities of ants, spiders, crickets, and other small insects. This has an impact on the plants throughout the rainforests because the insects that pollinate and provide ecosystems with other services that they provide for life to flourish. There is an even more influential importance to stop the spread of these frogs to delicate ecosystems where one imbalance can decimate populations of wildlife and plants.

Eradication attempts have been difficult. There is a widespread amount of reporting systems that I have found that people can input findings to local areas. Habitat limitation and plant nursery biosecurity efforts have been the main source of eradication attempt for these frogs.

Burmese Pythons are native to South East Asia and are known as some of the largest snakes in existence. Although frightening to humans, these snakes are nonvenomous. They primarily eat small mammals and birds by unhinging their jaw and swallowing their prey. Burmese pythons are usually 12 to 23 feet in length and weigh up to 200 pounds in the wild. While they thrive in their grassy marshlands and the jungles of South East Asia, the "exotic pet" craze of the 1980s brought Burmese Pythons to the United States. Before that, large snakes could be mainly seen at fair exhibits or for photo opportunities. South Florida became a hub for python owners. In the 1980s, some owners either purposefully released their snakes into the wild after learning they were difficult to care for or after the snakes grew up and doubled in size. Also, without a proper habitat, these snakes can easily escape from yards or poorly designed cages. It is estimated that about 2 million constrictor snakes have come through Miami due to the exotic animal trade. Since then, the Florida Everglades have been plagued with Burmese Pythons that are ruining the Everglades' ecological balance. 

A report in The New York Times entitled "The Snake that's Eating Florida" states, "They are believed to have eaten their way through the Everglades, bringing about startling changes in the ecosystem." Native mammals have dwindled in numbers in the Everglades. For example, no snake was big enough to eat mammals such as racoons or opossums until the release of the pythons. As the snake population grew, the pythons migrated to the mainland and put other species in danger. Florida's tropical climate is perfect for these snakes to thrive. Still, they have decimated the native wildlife such as Key Largo Woodrat. Also, they compete with other native predators such as the indigo snake. Burmese Pythons in the wild rarely attack humans. Still, there have been incidents of attacks, especially in pets that are not cared for properly. 

Recently, there have been attempts to quell the Burmese Python population in South Florida. The Florida Nature Conservancy started "Python Patrol" in 2008, where citizens report and capture pythons. Similarly, the Florida government has the "Python Challenge." They essentially offer "snake ranging courses" for citizens to go into the Everglades and spot and capture pythons. Pennsylvania News states, "The FWC, working together with the South Florida Water Management District, under the direction of Gov. Ron DeSantis, have removed 5,000 invasive Burmese pythons from South Florida's Everglades." The National Fish and Wildlife survey also has scientists looking at ways to remove or limit the python population.  The most promising would be a "freeze" coming to South Florida, but that would cause other issues with crops such as citrus. Additionally, the Obama administration enacted laws about the selling and transporting of constrictors as pets. This law seems to still stand during the Trump administration. Without proper management of these snakes, the everglades, which are already plagued with other invasive species, will suffer environmentally. Efforts need to be made locally, nationally, and personally. Pythons are interesting in the wild but should rarely be a pet because humans are the reason for this invasion. 

Caulerpa taxifolia, a particular strain of marine, green alga, is deemed an invasive species that is causing major environmental problems in the Mediterranean Sea. This alga is found natively in tropical waters such as the Caribbean, the Gulf of Guinea, the Maldives, Japan, and many more. In these waters, the patches of this alga are relatively small and cause no issues. The species was briefly found in California but was eradicated in 2006. In the early 1980s, it was even used for decoration in aquariums. However, a cold-water strain of this tropical alga was released into the Mediterranean Sea by the Oceanographic Museum of Monaco where it was established. At this time, it was a manageable population that could have been handled if it had been removed completely, but this was not done. Now, this alga covers thousands of hectares of the sea bottom across the Mediterranean, from France to Croatia, and it will likely continue to expand.

This alga is resistant to low seawater temperatures and can colonize most substrates, such as rock, sand, mud, and seagrass beds, allowing it to withstand various locations. It is much longer than its tropical strain and much larger. It is capable of rapid growth and reproduction due to its asexuality, making it hard to control. Dispersal occurs through fragmentation, including even the smallest of pieces. These fragments are created by the unintentional movement of the plants, by boats, sea currents, or fishing gear. Further, Caulerpa taxifolia has no natural predators in the Mediterranean. It is protected from fish, sea urchins, and herbivores due to the toxic effects of caulerpenyne compounds found within its foliage. Those fish that do eat the alga ingest the toxic compounds found within the leaves, making them inedible for human consumption. Caulerpa taxifolia smothers other algal species, seagrasses, and sessile invertebrates, reducing the diversity of native species and fish. It can kill up to 45% of the dominant Mediterranean seagrass, Posidonia oceanica, in just one year. It accomplishes this by out-competing other species for food and light by completely covering the species underneath or uses the toxic compounds found in its foliage to hard other organisms. Due to these facts, other seaweed or alga species are being replaced.

As far as eradicating this species, there was a successful attempt in southern California in 2000. The appearance of the Caulerpa taxifolia was likely due to improper dumping of the contents of marine fish tanks into stormwater systems feeding into the Agua Hedionda Lagoon in Carlsbad where the weed was found. This Caulerpa taxifolia population was small enough for eradication to be a possibility. To do this, the alga was covered with tarpaulins and held down onto the seafloor with sandbags, sealing the edges. Chlorine was then pumped under the tarpaulins, trapping it within, acting as a pesticide, and killed the alga. Any other organisms killed by the chlorine during this process were unintentional but deemed necessary to eradicate the weed and prevent any further spreading. California has since passed a law forbidding the sale, transport, or possession of Caulerpa taxifolia within the state. There is also a federal law forbidding the sale and transport of aquarium strain Caulerpa taxifolia.

https://cisr.ucr.edu/invasive-species/caulerpa-taxifolia-or-killer-alga

https://plants.ifas.ufl.edu/plant-directory/caulerpa-taxifolia/

The invasive species I chose to talk about is the Brown Tree Snake. The Brown Tree Snake is native to new Guinea and Australia. However, they have completely taken over the island of Guam. They originally invaded Guam during World War II. The brown tree snake snuck into war equipment, arrived in Guam, and eventually invaded the island. Today, there are around 13,000  brown tree snakes per square mile. Like its name suggests, they are great climbers and spend most of their time in trees. They also possess a very toxic venom. These two traits are what make them excellent invasive species. Because they have no competition with other predators and they themselves are prey to none, this is why the number of snakes keeps growing. Another benefit of the brown tree snake is when they first invaded the island there prey, which are mostly birds, were not used to being hunted by a snake because it had not ever been introduced in their environment. Because of this, the bird had no prior genetic adaptations to help defend themselves from the snakes. Now, the brown tree snakes cause many emergency room visits for humans each year as well as substantial power line damage. 8 out of 11 native bird species in Guam have been eradicated from the island due to the brown tree snake. The conservationists is Guam rely on one of two strategies to try and capture these invaders. The first is live trapping of the snakes in cages. The second is aerial delivery of toxic bait, which is pretty much rat poison. Both methods are not something I would like to engage in myself, but for those brave enough to carry out the duties, these are the best current options due to the habitat. 

Caulerpa taxifolia is a green alga that is invading parts of the Mediterranean Sea and western coasts of the United States. Caulerpa is used in aquariums, as saltwater decorative plants. It is bright green with ern like fronds that connect from a main stem. The fronds extend upward at long lengths. Caulerpa grows in shallow coastal lagoons, and also in deeper ocean waters. The species is native to the tropical oceans and seas, like the Caribbean. Caulerpa is a native alga to Hawai’i, but it has not demonstrated any invasive tendencies there. It has also invaded Australia, Eastern Atlantic, Western Atlantic, Indo-Pacifico, and the Gulf of Mexico. It has begun to spread to spread in California waters as well. It was accidentally introduced in the Mediterranean and California. Natural dispersion of the species occurs near the central invasion zone, however, is also transported by the anchoring systems of boats and fishing nets. It spreads by fragmentation, so even a small broken off fragment can form a new plant. 

Caulerpa is above average in size, length, growth rate and temperature tolerance. Another characteristic that allows the species to be successful is its longevity. Caulerpa is protected from being preyed on by sea urchin, fish and other herbivores because of its toxicity. In the Mediterranean, Caulerpa is causing a “major ecological event”. The species is invading and dominating all other seaweeds in the Mediterranean. It is invading the dominant seagrass, Posidonia oceanica, and killed up to 45% of the seagrass in one year. Since the species has become the main food source for herbivores, after killing off other seagrass, it is also causing herbivores to be eliminated because it is toxic to them. A decline in fish biomass in areas where Caulerpa is present is becoming an issue. 

There is a lack of natural predators to this species and it is essential to its success. According to the article, in 2000, authorities isolated and poisoned the Caulerpa patches found in the water’s northwest of San Diego, and it appeared successful. The patches of Caulerpa were covered with containment devices that trap adequate volume of water for treatment with chemical herbicides, while still protecting surrounding areas. There was also an infestation in Orange County in 2000 that was treated. Both of these strains of Caulerpa were identical to the aquarium strain of the species. Releases from aquarium into the ocean or indirectly through a storm drain were probably the sources of the Southern California infestations. Other ideas for controlling this invasive species have been to introduce a natural predator into their environment. This could create more problems, however. Caulerpa has been designated as a U.S. Federal Noxious Weed and is prohibited in the U.S. The Assembly Bill 1334 prohibits the possession, sale, and transport of Caulerpa in California. Since early eradication was not attempted from the Caulerpa manifestation in the Mediterranean, it now infests over 30,000 acres of the sea floor, and negatively impact tourism, fishing, and scuba diving. Infestations in Australia are reported to be the aquarium strain, that was also reported in New South Wales, and efforts are being made to control its spread. 

The Caribbean Tree Frog, also known to Hawiian natives as "quarter-size frog with the million-dollar voice,” was one of the many alien species that McGrath highlights in her National Geographic article. This species is native to Puerto Rico; however, it has invaded  Florida, Hawaii, the Galapagos Islands, New Zealand and a few other Caribbean islands since the 1970s. The state of Hawaii has even declared national emergency due to this animal and the threats it imposes. The frog, small insize, but loud in voice, has grown large populations throughout the areas it has invaded.

This species is successful in being invasive for many reasons. First, it is highly adaptable to different elevation and types of ecosystems, giving it the ability to survive in areas past its native range. Though it does thrive and reproduce best in higher elevations with more rain, it is able to live in most types of elevations. Even when reproducing, the species does not require the typical needed habitat; this species is a direct developer, so it doesn’t need bodies of water for its different life stages. Additionally, the species has a “voracious” appetite, giving it the ability to consume multitudes of other organisms, such as insects and spiders. Also, there are very few direct predators of this species in the areas in which it has invaded, giving it the ability to constantly expand. 

In Hawaii specifically, there is great cause for alarm over this species. In one night alone, a group of Caribbean Tree Frogs can consume 350,000 in one square hectare per night. This rapid consumption can lead to the decline of the species in which they are eating, typically plant material decomposing invertebrates, or ants, amphipods and isopods. This decrease also causes problems with bird population in the area. The birds are now being forced to compete with this species for food in a much more competitive environment than what they were previously used to. However, not everything that this species is doing is bad. The consumption of invertebrates by this species has led to an increase in the nutrient cycling rate, helping plants within the habitat to grow. 

There is much being done to try to eradicate this species from these habitats. Since 2005, Hawaii alone spends $2.8 million every year to try to track down and control this species. Since this species was originally introduced to these habitats on accident through horticultural trade, there have been strict guidelines put into place for plant trade. It is now mandatory for infested materials to be treated for these “pests” when coming into these areas. Physically catching the frogs has also become a helpful way to capture the species. By catching them, typically after modifying their habitats, people are able to capture the species. Additionally, the use of chemicals like citric acid, caffeine, and hydrated lime have been used to control the animals. Eradication is best completed when all of these methods are used together, as can be seen in the successful eradication of the species from the Hawiian island Oahu. 

https://www.cabi.org/isc/datasheet/84734#:~:text=E.%20coqui%20is%20a%20relatively%20small%20tree%20frog,quite%20adaptable%20to%20different%20ecological%20zones%20and%20elevations.

https://www.aphis.usda.gov/wildlife_damage/nwrc/publications/12pubs/pitt123.pdf