Climate Explained: Impacts on Wildlife

Climate issues can be difficult to understand. This series is designed to deliver what you need to know about some of the most prevalent issues in climate policy today. In 1,000 words, let’s explore what climate change means for wildlife in the Long Island Sound region. 

This article is written by Kaleigh Pitcher, a Policy Consultant at Save the Sound, working primarily in climate and environmental justice advocacy. She has a Master’s of Public Policy with a focus on Health and Social Policy from the University of Connecticut.  

Forested land adjacent to the Hudson River in New York.

How Does Climate Change Affect Plants and Animals? 

Humans aren’t the only ones feeling the effects of climate change. Rising temperatures and more frequent extreme weather events can lead to invasive species, food chain disruptions, habitat destruction, and disease outbreaks. The International Panel on Climate Change estimates that if global temperatures continue to rise at their current rate, 20-30% of plant and animal species are at risk of extinction by the end of the century. The Long Island Sound region is no exception, and it is already seeing adverse effects of the climate crisis. Some of the greatest threats to wildlife in our region are changes in weather, invasive species, and disease outbreaks. 

Animal Migration  

As the regional climate changes, it becomes less hospitable to some flora and fauna and more hospitable to others, causing changes to the natural environment as some non-native species migrate in and native species leave. It’s not just animals; even indigenous flora can leave an area. Species of plants, including trees, are capable of migrating, albeit over generations, through seed dispersal. Animals assist in this process, but seed dispersal is not likely to keep up with climate change. At the current rate of animal extinctions, fewer animals are available to assist with dispersal; recent research suggests that about 60% fewer seeds will be dispersed far enough to avoid detrimental impacts. Since natural migration is a slow process, some ecological organizations have begun moving species to more hospitable areas for their protection. Assisted migration is a beneficial tool in maintaining global biodiversity.  

Sea Level Rise 

Climate change is responsible for an increased frequency of extreme weather events. The northeastern United States has greater increases in extreme precipitation than any other region in the country, and more frequent and intense storms are damaging coastal forests and marshes through inundation. Sea levels have fluctuated throughout time, but coastal forests can no longer keep up with the accelerated rate of sea level rise. The result is ghost forests, or areas of dead trees near the coast that could not survive in salty or flooded soil. According to a Rutgers University study, by 2100, Connecticut and New York are expected to lose 1,965 acres and 4,552 acres of forest land, respectively, to future sea level rise.

Increasing water temperatures are also detrimental to aquatic species–iconic cold water species like lobster are disappearing from the Sound’s waters. For more information on how climate change is affecting our oceans, read our blog post on ocean acidification

Invasive Species 

Invasive species are a significant threat to biodiversity. An invasive species is defined as a living organism that is “not native to an ecosystem and causes harm.” The introduction of new species creates more competition for limited resources. Threats from invasive species can also include introducing new diseases, preying on native species, and disrupting the food web. These species can destroy or replace food sources, harming the environment’s biodiversity in the process. Climate change may also lessen the effectiveness of certain invasive species management practices. For instance, barriers designed to prevent the spread of invasive aquatic species may be designed for specific water flows, and stop working when extreme rain events change local conditions. 

Pictured: A Japanese Barberry, an invasive species in the United States.

As an invasive species management tool, the Early Detection Distribution Mapping System (EDDMapS) was developed to document the ranges and quantify the threat of invasive species. In New York, the most common invasive species is the Eurasian watermilfoil, an aquatic plant which crowds out native species. In Connecticut, that title belongs to the Japanese barberry, an attractive but harmful plant that provides a humid environment favorable to ticks. The plant is so damaging to the ecosystem that New York (among other states) has actually prohibited the possession, sale, and import of it.  

Long Island Sound is currently contending with harmful invasive species including common periwinkles, mitten crabs, and some types of red algae. Many species came to the region via transit or human interference, and once here, they can quickly overtake an ecosystem through prolific reproduction and species migration. For example, the mitten crab is a generalist predator that can alter the food web of Long Island Sound. It can survive in both salt and freshwater, and often burrows in stream banks, causing instability and erosion, which can be a flood damage risk. Another invasive Sound species, oyster thief, is a type of seaweed that commonly overgrows and disrupts shellfish beds. It received its name from its harmful propensity to attach to shelled mollusks, and, as it grows and gets more buoyant, lift the shellfish from its bed

Disease Outbreaks 

As our environment changes, new diseases are introduced and able to thrive. Climate change has been linked to an increased threat of zoonotic diseases, or diseases spread from animals to humans (or vice versa). Our region faces increasing threat of Lyme disease, as ticks thrive in warmer and more humid climates. This can affect many types of wildlife, including deer, squirrels, chipmunks, and raccoons, all of which are indigenous to the Long Island Sound region. The Northeast will be most severely impacted by Lyme disease cases as a result of climate change. Rising temperatures are also favorable to mosquitoes.

As ecosystems change, different wildlife will interact with each other, and this can contribute to cross-species transmission. Certain viruses, like influenza, Lyme disease, and rabies, can be transmitted between two different animals. With increased contact between species as they expand their ranges, new disease outbreaks can be expected, placing additional stress on certain populations. In one study, it was found that “over half of known human pathogenic diseases can be aggravated by climate change.”

And it’s not just pathogens that can affect human health–a warmer region is also more hospitable to certain types of plant allergens, like ragweed.

Mitigating the Effects 

Despite the threats posed to wildlife by climate change, there are means of mitigation and adaptation. Dramatically reducing greenhouse gas emissions is the only way to curtail climate change long term, but there are steps that can be taken mitigate its on-the-ground effects.

Green infrastructure, like rain gardens, watershed planning, and constructed wetlands, can increase climate resiliency and protect both our communities and our coastal ecosystems in the face of severe weather.

Ecological restoration can also combat invasive species. This includes replanting native species, assisted tree migration, and resiliency projects.

Learn more about your state’s invasive species, so you can help report harmful wildlife to the national database for better management. 

Explore some of Save the Sound’s efforts to protect our region’s wildlife through green infrastructure projects, ecological restoration, eelgrass planting, living shorelines, and more.  

Get Involved
Jump in

Join the fight! Memberships start at just $25 – support that’s badly needed now for a healthy, sustainable environment over the long term.

Join now

Take part

Tuesday, May 21, in Windsor, CT
Celebrate World Fish Migration Day! Join us for a river walk, networking, the premiere screening of “Reconnected: Restoring the Rivers of Long Island Sound,” and a panel discussion with experts and advocates.

See more

Connect with us

Stay in touch by joining our activist network email list. We'll keep you up-to-date with current initiatives, ways you can take action and volunteer opportunities.

Sign up