Invasive Species

When I go hiking, one of the first things I notice is whether an area has been taken over by invasive species. It detracts from my enjoyment of the experience because I understand how harmful they can be to an ecosystem. Invasive or nuisance species are usually non-native plants that spread and naturalize. They are able to out-compete with native species and can take over areas. Many invasive species began as ornamental plants because they are hardy and require little attention (EDD MapS 2016). In this blog I will focus on three invasive species that I saw in New York parks during my investigations: kudzu, porcelain berry, and phragmites.

Kudzu is a semi-woody, invasive vine that originated in China and Japan (Cornell University 2016a). It has beautiful purple flowers, which is what encouraged horticulturalists to begin growing it in the United States. It was then used as crop cover to prevent erosion and also as livestock feed. Now Kudzu is a prohibited and regulated invasive plant (Cornell University 2014) in New York. It is a nitrogen fixer, which means it can thrive in nutrient-poor soil, and is also drought tolerant. This combination made kudzu able to thrive in the US. Kudzu’s goal is to get as much sunlight as possible, so it climbs up trees and any other vertical structures, wrapping itself around it until it’s completely covered. Kudzu competes with trees for sunlight, nutrients, and water, but it also suffocates them. Sometimes the weight of kudzu vines leads to trees collapsing. It is rapidly growing and can out-compete native plants. This is very dangerous for wildlife as it can change the availability of food in their diet. There are enormous economic impacts from this fast-growing plant. Control of it can cost up to $200 per acre per year. It takes 5-10 year of focused eradication to get rid of a kudzu infestation and that means digging up their immense root structures and spraying herbicide.

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Kudzu in Pelham Bay Park

Like Kudzu, porcelain berry is a prohibited plant (Cornell University 2014), but only in certain states. It is not allowed in New York, but in other states it can still be used in landscaping and ornamentally. (Plant Conservation Alliance 2005). It originated in Northern Asia and is a type of grape vine with pretty berries, which is what drew so many horticulturists to use it. It spreads over open and wooded areas and grows over other plants, thus shading them out and taking over the habitat. A plant can grow up to 15 feet during one season. Porcelain berry is easily spread by birds and other animals who eat the berries, so it is important to get rid of the plant before flowering occurs. To remove it a combination of hand pulling and application of herbicides like triclopyr is recommended. It can take many years to fully eradicate a porcelain berry plant.

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Porcelain berry – Source: Gardening Know How

Phragmites is a bit more complicated than other invasive plants. There are a three different types of phragmites and only one of them is non-native (Cornell University 2016b). The problem species is Phragmites australius, also known as common reed, which was brought in from ship ballast in the late 18th century. Non-native phragmites likes to grow near wetlands, but it will take over any open area. It is a nuisance because it can decrease the salinity of marshes, decrease the area of usable habitat for animals, and increase the chance of fire to an area. Control of phragmites populations is very important, though one has to be careful to only remove the non-native species. Goats can be used to consume the plant. Also fire has been proven to sometimes be effective, but it is unclear if it gets hot enough to kill the plant’s rhizomes – an underground stem, which phragmites uses to reproduce. Cutting the plant and applying herbicides can also help. It is important to immediately reseed the area with native competitors to prevent recolonization and erosion from occurring. Phragmites roots help stabilize the soil and once it is eradicated native plants are needed to strengthen it.

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Phragmites in Freshkills Park

Though it may seem hard to control and prevent invasive species from taking over parks, it is vital to conserve these natural areas for the future. If you want to help get rid of invasive species, I recommend searching for a “friends of” or “conservancy” for your favorite local park and checking to see if they have any strikes against nuisance plants planned in the near future. The Natural Areas Conservancy would also be a great group to volunteer with to help protect New York City ecosystems. You can also look at volunteer vacation options with the American Hiking Society if you’d like to explore new areas while helping out a park.

 

 

Thank you for reading my blog. I have had a wonderful time exploring new parks across New York. I hope you learned something or felt encouraged to explore parks in your area. This will be my last post for a while, but I do plan to return with more entries about my explorations in the future.

Thanks again,

Lily

 

 

Bibliography:

Cornell University. 2014. New York State Prohibited and Regulated Invasive Plants. NYS Department of Environmental Conservation. NYS Department of Agriculture and Markets. http://www.dec.ny.gov/docs/lands_forests_pdf/isprohibitedplants2.pdf

Cornell University. 2016a. Kudzu (Pueraria montana). New York Invasive Species Information. http://www.nyis.info/index.php?action=invasive_detail&id=60

Cornell University. 2016b. Common Reed (Phragmites australis (Cav.) Trin. Ex Steud.). New York Invasive Species Information. http://www.nyis.info/index.php?action=invasive_detail&id=42

EDD MapS. 2016. Why Plants Become Invasive?. Early Detetion & Distribution Mapping System. https://www.eddmaps.org/about/why_plants_invasive.html

Plant Conservation Alliance. 2005. Fact Sheet: Porcelain-berry. National Parks Service. https://www.nps.gov/Plants/alien/fact/pdf/ambr1.pdf

Porcelain berry image: http://www.gardeningknowhow.com/wp-content/uploads/2012/07/porcelain-berry-vine1.jpg

 

 

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Retreat

As I have shown in my earlier science posts, sea level rise is one of the biggest challenges New York City will face due to climate change. The storm surge of Hurricane Sandy made it clear that the city was not equipped against floods caused by extreme weather events. In earlier posts two options were explained, a “soft” approach – beach nourishment – and a “hard” approach – barriers. In this post we will discuss retreat, the option left when nothing else will work.

Retreat is the act of moving away from the shoreline. Residents are encouraged to sell their land and then the government allows the land to return to its natural state. The option was discussed in Gornitz et al.’s 2002 paper Impacts of Climate Change on NYC Coasts. In Storm Surge, Sobel mentions a similar plan in the Netherlands. “Return to the River” forced residents, who were mostly farmers, to leave an area, which was then returned to a floodplain. A few negotiated to stay in the area, but the majority left.

After Hurricane Sandy, it became even clearer that retreat would be necessary. While Bloomberg said that retreat was not an option (Revkin 2013), Governor Cuomo signed off on the purchase of three neighborhoods in Staten Island, Oakwood Beach, Ocean Breeze, and Graham Beach, for retreat as part of the Hazard Mitigation Grant Program. These neighborhoods had almost all of the residents agreeing to sell their homes, with a few holdouts (Rush 2015a). During his State of the State address, Cuomo said, “There are some parcels that Mother Nature owns […] She may only visit once every few years, but she owns the parcel and when she comes to visit, she visits” (Homeland Security News Wire 2013). Many other neighborhoods along the east coast of the island, all of which were hit very hard by the storm surge of Hurricane Sandy, wanted to get in on the buyout, but a representative of Cuomo said the governor would not authorize the purchase of the entirety of the coast. The purchased neighborhoods have already begun to be demolished and reestablished as wetlands. The land would be planted with native grasses and retention pools would be built to capture the rainwater. The process cannot be completed until all residents leave. A large section of one neighborhood is currently owned by a developer who is holding out on selling the land, which poses a problem for the reestablishment (Rush 2015b).

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A home in Oakwood Beach waiting to be demolished – Source Urban Omnibus

There are other options for homeowners who want to relocate. “Build It Back” is a program which offers to pay for repairs or elevation of homes hurt by Hurricane Sandy. An acquisition program run alongside “Build It Back” offers to purchase homes on their own instead of a neighborhood buyout. The difference between this type of purchase and a group buyout is that individual purchases do not get returned to nature, instead they are redeveloped and new structures are built. This is not as good of a plan as retreat. Most of the areas that become severely flooded during storms used to be wetlands and were backfilled to make room for buildings. More than half the people who died during Hurricane Sandy lived in areas that used to be wetlands (Rush 2015a). Rebuilding on these areas could increase the number of fatalities in the future.

Retreat, though the severest choice in the fight for the coast, is the safest option both for human life and wildlife. Beach nourishment and barriers both lead to erosion and damage the habitat of wildlife that lives in the area. They are also incredibly costly and though barriers can reduce flood levels, they still leave residents in danger from the water that makes it over the seawall. Retreat puts no one in danger and returns the land to its natural state. Wetlands will protect the coast from sea level rise and storm surges. They will serve as a buffer for nearby residents from the elements and also vice versa by stopping runoff from going directly into the ocean.

In the next, and final, science blog we will take a look at some of the invasive species I got to know during my visits to New York parks.

 

 

Bibliography:

Gornitz, V., S. Couch, and E. K. Hartig. 2002. Impact of sea level rise in the New York City metropolitan area. Global and Planetary Changes 32: 61-88.

Homeland Security News Wire. 2013. NY to buy, demolish beachfront homes, make way for storm buffers. Homeland Security News Wire. http://www.homelandsecuritynewswire.com/dr20130207-ny-to-buy-demolish-beachfront-homes-make-way-for-storm-buffers

Revkin, A. C. 2013. Can Cities Adjust to a Retreating Coastline. The New York Times. http://dotearth.blogs.nytimes.com/2013/08/22/can-cities-adjust-to-a-retreating-coastline/?_r=0

Rush, E. 2015a. As the Seas Rise: Managing retreat along New York City’s Coasts. New Republic. https://newrepublic.com/article/123182/managing-retreat-along-new-york-citys-coasts

Rush, E. 2015b. Leaving the Sea: Staten Islanders Experiment with Managed Retreat. The Architectural League’s Urban Omnibus The Culture of Citymaking. http://urbanomnibus.net/2015/02/leaving-the-sea-staten-islanders-experiment-with-managed-retreat/

Sobel, A. 2014. Storm Surge: Hurricane Sandy, Our Changing Climate, and Extreme Weather of the Past and Future. HarperCollins. New York, New York, USA.

Vinnitskaya, I. 2013. NY State’s Governor Cuomo’s Solution for Ravaged Homes in NYC’s Coastal Region. Arch Daily. http://www.archdaily.com/331154/governor-cuomos-solution-for-ravaged-homes-in-nycs-coastal-region/

Image: http://urbanomnibus.net/redux/wp-content/uploads/2015/02/FoxBeach011_resize-650×465.jpg

 

 

Beach Nourishment

Beaches are an important form of recreation, especially in the summer, but, because of climate change, they are in danger. Rising sea levels as well as the increased potential of dangerous storms exacerbate beachfront erosion. More than 70% of the world’s beaches are experiencing losses due to erosion (Bird 1985). One method of fixing this problem is beach nourishment. Though there are benefits to this solution, there are also large costs, both environmentally and financially.

Beach nourishment, or replenishment, is the act of removing sand from offshore sand bars located close to the beach and replenishing the beach with this sand. This is ideal because the sand is usually a close match to the grain size of the original sand. (Gornitz et. al 2002) If it is not a perfect match it will alter the sand composition of the beach, which can upset some beach goers. Beach nourishment is considered to be a soft approach because it is only a temporary fix to the large problem of erosion. It needs to be repeated often so as to continue the effect. This soft approach is preferred over hard approaches, such as the building of groins or sea walls, because those structures often cause increases in erosion down drift. Replenishment benefits communities because beaches increase tourism and, if located in residential areas, usually increase property values. In some cases, individuals are willing to pay for beach replenishment. Beaches also help to protect coastal areas from storms – they prevent sediment overwash and stop salt water from inundating coastal wetlands (ASBPA 2007).

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Sand being moved to replenish a beach – Source: Sea Turtle Camp

Many New York City beaches have undergone beach nourishment. After the damaging effect of Hurricane Sandy, Rockaway Beach has had 3.7 million cubic yards of sand moved to restore its beach. In addition, Coney Island, the East and South Shore of Staten Island, and Orchard Beach in the Bronx were locations of beach nourishment. Hurricane Sandy also greatly damaged other beaches. In three waterfronts of NYC (New York Harbor, Raritan Bay, and Jamaica Bay) 25% of beaches and 28% of beaches along the Long Island Sound lost between 50 and 100 feet of sand due to the effects of erosion (Anderson 2013). With chances of severe storms increasing because of climate change, according to the IPCC Summary for Policy Makers (2013), one must expect that beach nourishment will be increasingly necessary if New York wants to retain current beach levels.

Moving that much sand has a cost. Gornitz, et. al (2002) states that over half a million dollars has been spent in New York state alone on beach replenishment. Rockaway Beach’s restoration project, which included reconstruction of the boardwalk, construction of baffle walls, and sand retaining walls, as well as beach nourishment, cost more than $140 million dollars. Before that $216 million had been spent to replenish Rockaway’s beaches (Nessen 2013). From 1923-1995, $25 million dollars was spent on beach nourishment for Coney Island. These costs will only increase in the future as more sand will be needed for replenishment and the sand closest to the beach will be depleted. In addition, sand added through beach nourishment erodes two to three times faster than natural beaches (Barber n.d.). This will add to the amount of nourishment needed.

As well as these financial effects, beach nourishment negatively affects the environment. The moving of sand can make the water too muddy, bulldozers can squish species that reside on the beach, or change the shape of the beach to such a level that it makes it impossible for certain species to reside there. After Hurricane Sandy, even though beaches were heavily eroded, there are possible positive effects for animals. The flattening of beaches in Breezy Point, the Rockaways, and Fire Island could enable the piping plover, which is endangered, to nest in new places (Anderson 2013). The changes on the beach caused by erosion or storms are natural and beneficial to animals that make their habitat on the shore, while human caused beach nourishment can make life difficult of species like sea turtles who lay eggs on beaches.

Beach nourishment is a complicated matter. While it helps protect coastal areas and allows for recreational use of beaches, it can also destroy ecosystems and be financially costly. In the fight to conserve recreational spaces in the face of climate change, we much decide whether protecting our beaches is worth the cost it carries.

 

 

Bibliography:

Anderson, J. 2013. Rebuilding the Coastline, but at What Cost?. New York Times. http://www.nytimes.com/2013/05/19/nyregion/rebuilding-the-coastline-but-at-what-cost.html?pagewanted=all&_r=1

ASPBA. 2007. Beach Nourishment: How Beach Nourishment Projects Work. ASPBA. http://www.asbpa.org/publications/fact_sheets/HowBeachNourishmentWorksPrimerASBPA.pdf

Barber, D. n.d. Beach Nourishment Basics. Bryn Mawr College. http://www.brynmawr.edu/geology/geomorph/beachnourishmentinfo.html

Bird, E.C.F., C. Wiley. 1985. Coastline Changes: A Global Review. 219 pp. New York, New York, USA.

Gornitz, V., S. Couch, and E. K. Hartig. 2002. Impact of sea level rise in the New York City metropolitan area. Global and Planetary Changes 32: 61-88.

IPCC, 2013: Summary for Policymakers. In: Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change [Stocker, T.F., D. Qin, G.-K. Plattner, M. Tignor, S. K. Allen, J. Boschung, A. Nauels, Y. Xia, V. Bex and P.M. Midgley (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA.

Nessen, S. 2013. The ‘Most Expensive Beach in America’ Gets More So. WNYC. http://www.wnyc.org/story/299390-dumping-more-sand-most-expensive-beach-america/

NYC Parks Department. n.d. Rockaway Beach Restoration. NYC Parks Department. https://www.nycgovparks.org/facility/beaches/beach-recovery

Image: https://www.seaturtlecamp.com/coastal-development/

Barriers

With the threat of rising sea levels, the New York City government has to seriously consider how to protect its land. New York is not only threatened by elevation of the water level, which could decrease the size of coastal areas, but also by the increasing damage that could be caused by storm surges. One way that the coast could be protected is by building barriers.

Examples of barriers include seawalls, groins, and jetties. Seawalls are exactly what they sound like, walls built in the sea, which protect the coast from being inundated with too much water (Gornitz et al. 2002). Groins are a series of posts or sometimes a wall, built onto a beach that is meant to catch littoral sand that is moved by the currents. Jetties are long strips of land that make inlets stable and protect harbors from the worst effects of waves. The decision of where to place barriers and what kind of barrier to use is vitally important, both to the area it protects and the ecosystem it affects.

After the disastrous effects of Hurricane Sandy, New York City had to consider what can be done to protect itself. One option that was first thought of was to build moveable barriers in the ocean, like those found in the Netherlands. (Sobel 2014) There are examples of barriers like that as close as New England, protecting small channels from being flooded with water. But those types of barriers only work for small areas. The shores of New York are too long to be protected by a moveable barrier. Bryan Walsh wrote in Time that a Dutch-style barrier surrounding New York City from Sandy Hook, New Jersey to Rockaway Beach would be an option, but would cost anywhere around $10 – $15 million (Walsh 2012). Christa Marshall in Scientific American wrote about a proposal to build two different seawalls, first a seawall in the East River, then a seawall from Sandy Hook to Rockaway Beach (Marshall 2014). This double seawall would create an extra layer of protection. It is doubtful that this will completely stop all flooding, but it would limit the amount of damages that would occur in New York. Still, though barriers are able to stop water from damaging the land, they also have great consequences.

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A rendering of a sea wall between Brooklyn and Staten Island – Source Fox News

The greatest consequence of coastal barriers is erosion. With seawalls, erosion occurs both at the base of the seawall (Gornitz et al. 2002) and further down the coast where the seawall does not extend. These areas suffer even more than they usually would because the seawalls just move the waves further along and when they reach an unprotected area, the waves are even more powerful than normal (Dunn 2009). If rubble is placed directly next to the seawall, erosion at the base can be decreased. Groins, if they are not placed in the right spot usually increase erosion of beaches further downstream, as do jetties. Erosion of beaches causes habitat loss for animals who nest or lay eggs there and can decrease the number of invertebrate species who live on the beach (Dugan and Hubbard 2010).

New York must consider the cost of building barriers. Though they might protect the city from flooding, they could also pass the consequences further along to other cities. Building barriers is considered to be a “hard” approach. In the next science post, I will investigate a “soft” approach, beach nourishment.

 

 

Bibliography:

Dugan, J.E., and D. M. Hubbard. 2010. Ecological Effects of Coastal Armoring: A Summary of Recent Results for Exposed Sandy Beaches in Southern California. US Geological Survey, Department of Interior. Scientific investigations report, 2010-5254. Reston, VA, USA.

 

Dunn, P. 2009. Can Seawalls Prevent Beaches from Eroding?. MIT School of Engineering. http://engineering.mit.edu/ask/can-seawalls-prevent-beaches-eroding

Gornitz, V., S. Couch, and E. K. Hartig. 2002. Impact of sea level rise in the New York City metropolitan area. Global and Planetary Changes 32: 61-88.

Marshall, C. 2014. Massive Seawall May Be Needed to Keep New York City Dry. Scientific American. http://www.scientificamerican.com/article/massive-seawall-may-be-needed-to-keep-new-york-city-dry/

Sobel, A. 2014. Storm Surge: Hurricane Sandy, Our Changing Climate, and Extreme Weather of the Past and Future. HarperCollins. New York, New York, USA.

Walsh, B. 2012. Sandy: What a Coastal U.S. Can Learn from Other Threatened Cities. Time. http://science.time.com/2012/11/05/sandy-what-a-coastal-u-s-can-learn-from-other-threatened-cities/

Image – http://www.foxnews.com/science/2013/10/29/one-year-after-sandy-progress-on-20-billion-sea-wall.html

 

Hurricane Sandy

It’s one of the signals of summer – the weathermen announce that it’s hurricane season. To skeptics, saying that Hurricane Sandy was caused by climate change, would be considered ridiculous. But, Sandy’s consequences are a clear sign of the changing climate and it could be just the first of many severe acts of nature in the future. The consequences of storms like those could be disastrous for New York and any other areas affected.

The majority of Atlantic hurricanes head into the ocean and dissipate, but Sandy followed a different path. It took a left turn and ran straight into NYC. This is not necessarily directly caused by climate change, but global change could create increases in certain extreme weather events. The IPCC (Intergovernmental Panel on Climate Change) states in their Summary for Policy Makers (2013) that there will be an increase in near-storm precipitation in the future, but there is also a low chance that overall tropical cyclone frequency would decrease. This intensification of the hydrologic cycle occurs because greenhouse gasses warm the atmosphere and make evaporation and precipitation occur more forcefully. These predications also say that there could be an increase in the number of intense hurricanes.

Even with these predictions stating that there might be a decrease in storms, future hurricanes will have an even worse effect than they used to because the seas will swell, causing an increase in storm surges. In Adam Sobel’s 2014 book Storm Surge: Hurricane Sandy, Our Changing Climate, and Extreme Weather of the Past and Future Sobel says that because of the increase in greenhouse gases, the planet could warm and make land ice melt more, thus swelling the ocean. This means that future hurricanes could have even worse flooding effects because of the rising sea level.

Sandy had many disastrous consequences for New York. New York is in a generally low-lying area. When New Orleans was hit with Katrina, the topography proved to be one of the biggest causes of destruction. With almost half the land below sea level, hurricane floods created standing pools of water, destroying many parts of the city. The low-lying areas in New York faced similar problems during Hurricane Sandy and will be problematic in the future as well. Subway tunnels flooded, as did all the automobile tunnels in Manhattan, except for the Lincoln tunnel. West Harlem Waterfront Park was submerged; Coney Island, Brighton Beach, most of Jamaica Bay, the barrier islands of Brooklyn and Queens, and many neighborhoods in Staten Island were all completely flooded (Sobel 2014). The rising sea levels caused by climate change could make the next storm to hit New York even worse than Sandy. The sea level around New York City has already risen a foot during the past hundred years and that number will grow as the planet continues to warm (Sobel 2014).

During the storm 3,444 trees fell into city streets. 3,403 limbs fell down and 1,577 branches were left hanging (Foderaro 2012). This reflects a great loss to the city’s green landscape, but that wasn’t the only effect. The salt water that flooded the city during the storm is believed to be the cause of 10,000 dead or declining trees all over New York (Langfield 2015). The city plans to plant more salt tolerant species to replace these trees, which will hopefully save the plants in the future.

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Trees being taken down after Hurricane Sandy – Source: The New York Times

One final effect of Hurricane Sandy is how it has impacted the parks in New York City. Three years after the storm, Inwood Hill Nature Center in Manhattan, Taafle Playground in Brooklyn, and Wolfe’s Pond Park in Staten Island all remain closed due to the effects of Hurricane Sandy. As will be mentioned in my blog post about Jamaica Bay, the West Pond loop trail was rendered impassable by the storm and still remains so.

Climate change will cause storms to be even less predictable than they already are and will make them produce even more destruction than previously seen. Hurricane Sandy is a perfect example of what will happen. New York must take up measures to protect its resources from both the rising sea levels and the damage that will be caused by extreme weather events. In the next science blogs I will look at three different measures that could be taken to counteract these effects: barriers, beach nourishment, and retreat.

 

 

Bibliography:

Brenner, M. 2015. Understanding the effects of Hurricane Sandy on Atlantic Coast tidal marshes, wildlife. Hurricane Sandy Recovery. https://www.doi.gov/hurricanesandy/understanding-effects-hurricane-sandy-tidal-marshes-wildlife

Environmental Defense Fund. 2013. Sandy Success Stories: New York, New Jersey June 2013. Environmental Defense Fund. https://www.edf.org/sites/default/files/sites/default/files/content/SandySuccessStories_June2013.pdf

Foderaro, L. W. 2012. Storm Inflicted a Beating on City Trees. The New York Times. http://www.nytimes.com/2012/11/12/nyregion/hurricane-sandy-inflicted-a-beating-on-new-york-city-trees.html?_r=0

IPCC, 2013: Summary for Policymakers. In: Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change [Stocker, T.F., D. Qin, G.-K. Plattner, M. Tignor, S. K. Allen, J. Boschung, A. Nauels, Y. Xia, V. Bex and P.M. Midgley (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA.

Langfield, A. 2015. New York City still feeling the wrath of Superstorm Sandy. CBS Money Watch. http://www.cbsnews.com/news/new-york-city-still-feeling-the-wrath-of-superstorm-sandy/

Long Island Press. 2014. Sandy 2 Years Later: Winners and Losers on Long Island. Long Island Press. https://www.longislandpress.com/2014/10/29/sandy-2-years-later-winners-and-losers-on-long-island/

NYC Parks Department. 2016. Notices: Park and Facility closures. NYC Parks Department. https://www.nycgovparks.org/news/notices

Sobel, A. 2014. Storm Surge: Hurricane Sandy, Our Changing Climate, and Extreme Weather of the Past and Future. HarperCollins. New York, New York, USA.