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The Science Survey

We've got the news down to a science!

The Science Survey

We've got the news down to a science!

The Science Survey

The Invasive Species Threat: A Closer Look at New York’s Ecological Invaders

New York is known for being diverse, but it also holds a diverse range of non-native species that threaten the environment.
The spotted lanternfly became one of the most recognizable invasive species in New York City due to the large swarms identified last year. After numerous reports from civilians and a collective effort to get rid of them, the SLF epidemic came to a close. (Photo Credit: Cbaile19, CC0, via Wikimedia Commons)

There are a few things I remember about my summer last year such as constant trips to the mall with friends, frequent family visits, going to the beach and enjoying the fresh air at my local park. Every moment was filled with enjoyable and laughable memories, but other than providing me with enjoyable experiences to reflect on, all of these activities shared one thing in common. And it all connects back to one miniscule bug: the lanternfly. 

They were everywhere. My sister and I would walk up from the underground parking lot at our local Target, and the stairs were littered with dead lanternflies. My mother hosted a barbeque at some park and  I would shriek every time a lanternfly jumped onto the picnic blanket. Even my bus stops were building their own lanternfly graveyard, lined up with around 50 squashed red bugs.

Lanternflies are just one example of invasive species that reside in New York City. Invasive species are exactly what they sound like: unwanted guests from various parts of the world that range from different plants and animals. These species are non-native to an area and adapt quickly to their new environment. They also multiply at an incredible rate. Invasive species are not just seen as annoyances, however. They are deemed dangerous due to the many environmental, economic, and societal issues they cause.

But how does an organism manage to invade another region? The answer is actually quite simple. Humans have entered a new era of global trade, and with new technology to improve transportation across the world, we have accidentally made it easier for many species to move alongside us. Bugs and other small animals can get into cracks in wood, whipping pallets, and crates that are present inside ships and large marine transportation methods. Although very rare, due to modern restrictions and security, species can also travel airborne. The Mediterranean fruit fly has been reported to be imported from various luggages and packages, and many mosquitoes have survived long air travel times. 

However, sometimes invasive species are introduced to ecosystems intentionally, depending on the surrounding circumstances. Many farmers, for instance, deliberately introduce invasive species into their farms in order to control another native species. The cane toad is one such animal that helped control sugarcane pests in Australia. However, it soon grew to cause serious ecological harm. The Nile tilapia fish, although not introduced by farmers, are sometimes intentionally used to control aquatic weeds and algae in various irrigation canals and ponds. 

Let’s take a closer look at the lanternfly. The spotted lanternfly are small insects with black and white spots wearing striking wings at the front and back portions of their body. The back wings are a mixture of red and black with white bars and the front wings sometimes have an ombre of brown and gray hues. 

These insects are small; there’s no denying it. However, they pose a threat to New York City’s plant ecosystems. The spotted lanternfly feeds on the sap of plants using their sucking mouthparts. As a result, plants become weaker and they become immensely vulnerable to diseases and other insects. As of what we know, the lanternfly has attacked over 70 known woody plant species such as rose, maple, and river birch. (cnr.ncsu) They swarm in large numbers usually and many public places such as restaurants, malls, and even underneath buses, have been amassed by these insects. 

Due to the insects aggregating on public transportation, they travel quickly and multiply quickly. Last year, the lanternfly population in the city was at its peak. In order to quickly handle the situation, the department of invasive species released a statement: if you see it, kill it. This goes for the insects’ eggs as well. Many lanternfly eggs are laid in public places; underneath restaurant doors, station ledges, on public chairs and benches. 

Another invasive species known to harm New York City’s plant ecosystem are the Asian Longhorn Beetles — an invasive wood-boring insect that particularly attacks New York’s hardwood forests. Like the spotted lanternfly, they are native to regions in Asia, specifically China and Korea. 

Unlike the SLF (spotted lanternfly), the Asian Longhorn Beetle (ALB) is large, grows approximately 1.5 inches in length, and is colored deep black with small white dots on their wing cases. On occasion, their antennas can grow twice as long as their actual bodies. Due to their size, they are easily recognizable. 

These beetles were first discovered in Brooklyn during 1996. They originally infested Norway maple trees, and have caused a lot of damage to New York’s forests. It is assumed that larvae and pupae traveled from China in wooden packing material due to international trade. The adult beetles finally emerged in New York Harbor, the heart of all of New York City’s exports and imports. Soon, more infestations were found in Manhattan, Queens, Staten Island, Islip and central Long Island. 

ALBs have a detrimental effect on forests. They attack and kill hardwood trees from the inside. They enter the heartwood and a large swarm of them can kill a tree by girdling (destorying/injuring the bark) them. They feed on the sap of trees and cause open wounds; trees that are attacked are immensely weakened and are typically killed due to being infected with diseases and other insects. Not only that, the ALB reduces the quality of wood and lowers the wood supply. This means the wood industry is more vulnerable to economic losses, creating a huge problem. After all, the hardwood forest industry is worth billions of dollars from selling a variety of wood products. 

The beetle favors maple species, and the damage caused to these trees greatly hurts the maple syrup industry. This is not just a New York City problem. Canada, which also exhibits the invasive species in their own forests, is worth about $100 million dollars each year from maple syrup alone. Since the ALB has no predators inside of North America, they repopulate rapidly. The rising swarms of beetles causes great damage to ecosystems if not contained properly. The hardwood tree species that ALB favors so greatly make up a huge portion of natural and urban forest canopies in Canada and in some parts in upstate New York. The northeastern side of the U.S is especially known for their beautiful and lush forests, and the widespread ecological damage caused by the insects will impact tourism and recreation values. 

Ironically, the very same trees that the ALBs have first attacked are also considered invasive species. The Norway Maple Trees are a bit different from the ALB and the SLF. The invasive trees themselves are a product of deliberate infestation due to the aesthetic appeal of the plant. During the early American nursery trade, the Norway Maple was planted in North America solely for its appeal. 

The scientific name for the Norway Maple Trees is Acer platanoides and they turn into a beautiful mixture of orange and yellow during the fall. However, they are reducing the population of various other native tree species. (Photo Credit – Włodzimierz Wysocki, CC BY-SA 3.0 <https://creativecommons.org/licenses/by-sa/3.0>, via Wikimedia Commons)

The Norway maple was deliberately planted in the continent and it first was documented in 1756. John Bartram had acquired seeds from England and then decided to plant them in his own garden in Philadelphia. It didn’t take long for the species to appear all through catalogs and newspapers and soon it reached its peak popularity for being known as the ideal street tree. These trees grow especially quickly and are very beautiful during the fall. They are also strong to handle tough and dense urban environments and are able to grow in compacted soil, limited root space, and in air polluted areas. Popular cities in northern California, Canada, and of course, New York City, soon reported many Norway maple trees. 

The tree can grow up to 40 to 90 feet long depending on the specific growing conditions and the diameter of the stem can reach 5 feet. Its leaves are relatively large, sometimes reaching 10 inches in width and they turn a deep yellow color during the fall season. Flowers appear on the trees during early spring and they grow in big groups of 10 to 30 in numbers. 

The trees are very similar to the Sugar Maple tree (which is native to North America) but there are a lot of key differences to distinguish the two. Firstly, the Sugar Maple leaves are smaller and their leaves turn red or orange in autumn. When you break off a leaf stem and peek at the sap, sugar maple trees and its sap are clear while the Norway Maple sap is thick and white. 

The seeds spread quickly due to wind and are very easily carried from the cities into natural areas. This is a problem, as the trees grow tall and pose a threat to native plants and trees. With the Norway maple joining the party, other trees have to fight for sunlight due to the tall nature. Additionally, everything about the Norway maple is fast. Other species cannot keep up. Studies have shown that with areas containing Norway maple trees, there is less diversity underneath. Since the maple trees also provide dry shade underneath their towering bark, studies have also claimed that they release allelopathic chemicals deep into the soil that hinder the growth of other plant species. 

There are also many types of aquatic invasive plants residing in New York. The Hydrilla originates in Asia and it is actually considered one of the most difficult invasive species to contain and deal with due to its complexity.

The plant, which originates in the wetlands of Asia, firstly grows along the bottom of rivers, lakes, and ponds during the late spring and hot early summer seasons. They vary in color depending on the water conditions. For instance, in brackish water, the color will turn a deep brown. In water that contains a high amount of dissolved calcium and magnesium, it will develop a white coating (which is a coating of calcium carbonate ringing the edges.) 

The tubers of the Hydrilla rise to the surface and thus create a thick wall of vegetation. Each of the “branches” have many leaves that swirl around the center and the leaves grow along the same plane. This shape of the Hydrilla is called a whorl and every whorl contains 4-8 blade-like leaves with sharp tooth-like edges. 

The main issue is the vegetation walls. They grow so thick that it’s hard for boaters, swimmers, and fishers to move around. Many wet areas in New York are known to be an ideal spot for tourists and if an area suffers from an infestation, these municipalities will lose income. Additionally, waterfront property values can be greatly reduced. The costs of management when dealing with the Hydrilla are expensive and take a while, due to the root of the problem being underneath the waters, far from the surface. 

The vegetation also creates a huge shade. Like with tall trees in dense forests, they form a barricade for other native aquatic plants to get sunlight, and thus slowly harms them in the process of them thriving. The Hydrilla displaces native wildlife and also decreases the amount of dissolved oxygen in the water. This kills fish. Not only does the native population of our fish get lower and lower, the Hydrilla also harms the fish industry by lowering the amount of fish inside the waters and also interfering with fishers and boaters. 

The European Starling are found almost everywhere in North America, but as beautiful as these birds are, don’t let that fool you. They are extremely disastrous to the fruit economy. (Photo Credit: Solitude at English Wikipedia., CC BY-SA 2.0 <https://creativecommons.org/licenses/by-sa/2.0>, via Wikimedia Commons)

Finally, the European Starling is an invasive species native to Europe and some parts of West Asia and North Africa. These birds are seen almost as frequently as pigeons and aren’t just New York City’s problem. There are currently 150 million of these birds in North America alone. Picture that. How did these birds arrive and spread so quickly? 

The European Starlings were first seen in Central Park in 1890. They are easily recognizable, with their beautiful coat of feathers with polka dot patterns and a purple-green sheen. The interesting thing about their origin in North America is that it is not confirmed. There is a rumor that they were originally introduced by a man named Eugene Schieffelin in New York City due to his obsession with William Shakespeare. Schieffelin wanted to make the plays as realistic as possible and decided to bring the European Starling, a bird mentioned in the plays, over to the city. Though there is not enough viable evidence to prove this to be true, the story is an example of how invasive species can be intentionally planted for various reasons. 

Starlings have been in North America for about 130 years and as a result, have created a lot of destruction regarding the ecosystem. The birds damage numerous varieties of fruits, such as apples, blueberries, cherries, figs, grapes, peaches, and strawberries. The Starlings eat the fruits, but they also peck and slash at them, causing the quality of the products to decline dramatically. The birds cause the fruits’ susceptibility to diseases to increase and the damage worsens. 

In a survey from 2012, producers indicated that there was a $51 million damage payout to sweet cherries and $33 million to blueberries. The total amount of bird damage from the Starlings was estimated to be $189 million. 

Starlings are also birds that are both biological and mechanical vectors of pathogens that transmit and amplify bacterial, fungal, parasitic and other viral pathogens with ease. They can carry Salmonella and several Escherichia coli serotypes, as well as Campylobacter jejuni and Chalmydophilia psittaci (which are different bacteria types.)  They can carry all of these pathogens without showing any symptoms of illness, increasing the chance that other animals and humans can get the diseases. 

Starlings have spread all across the country, but in urban environments, the birds can cause disruption to ventilation and unsafe clogs. In New York City especially, with a lot of buildings congested in one place, Starlings use those discrete areas to make nests. They use a lot of vents which can clog them and create unsafe venting conditions. They also compete with other native bird species for cavity nesting sites. The competition harms species such as the Eastern Bluebirds and the Purple Martins. 

Clearly, there are a lot of invaders residing inside such a huge urban environment like New York City. These species move quickly and adapt in different ways, which make it difficult to contain them. This is why reporting any sighting of these animals is crucial to the NYSDEC. The Department of Conservation supports the Bureau of Invasive Species and Ecosystem Health (BISEH) by providing assistance and immediate action whenever a threat is reported. The departments have grant opportunities, which are funded by EPF. These grants greatly help numerous non-profit organizations and municipalities in order to control and research invasive species. 

The Water Chestnut is another example of an aquatic invasive species residing in New York. Here is a CIP intern participating in removing the Water Chestnut from the Long Island waters at the Long Island National Wildlife Refuge Complex. (Photo Credit: U. S. Fish and Wildlife Service – Northeast Region, Public domain, via Wikimedia Commons)

The responsibility does not only fall on the DEC’s shoulders, however. Normal civilians walk through the sidewalks of the city, visit numerous tourist centers, and take strolls through parks. We have all these opportunities to encounter the invasive species talked about above as well as other invaders. This means we also have the opportunity to report them. The DEC and the BISEH rely on information based on the reported incidents, so it is up to us to make sure the encountered species are accounted for. 

We want to make sure our city, our state is protected from harm. By recognizing the threat of these species and understanding their impact on our environment and our economy, we should empower ourselves to take action. Each of us has a role to play in preserving the biodiversity of New York and safeguarding the ecosystems for future generations. Support the local conservation efforts, take part in invasive removal programs, and  importantly, spread awareness. 

There are many links that you could use to stay informed and to stay aware. If you encounter any sort of invasive species, make sure to take action quickly. The appropriate link to document a sighting for New York state can be found here. For more information regarding the DEC or how to regulate invasive species, the link can be found here

Each of us has a role to play in preserving the biodiversity of New York and safeguarding the ecosystems for future generations. Support the local conservation efforts, take part in invasive removal programs, and  importantly, spread awareness. 

About the Contributor
Maliha Chowdhury, Staff Reporter
Maliha Chowdhury is an Editor-in-Chief and a Social Media Editor for ‘The Science Survey,’ and she enjoys the value of truth that is expressed in journalistic writing. She loves the idea of spreading beautiful stories in the form of both writing and detailed photography, and she hopes to one day publish a piece that gains a broad reading audience. Maliha also enjoys photography, capturing moments with any form of camera, whether it is of objects or people. She believes that even one photograph can truly enlighten people by evoking various emotions in the viewer. Maliha is currently a member of the Photography club. Along with photography, Maliha enjoys writing all sorts of prose pieces, including dystopian stories, and also poetry. She also loves watching a variety of shows and reading novels. Maliha plans on pursuing a scientific-centered career, specifically in the field of Astronomy, but she still wants to hold onto the love of reading and writing for as long as she can.