The University of Rhode Island’s Environmental Data Center recently completed a major update of submerged aquatic vegetation (SAV) mapping for the Long Island Sound (LIS) and the Peconic Estuary (PEC), marking the first region-wide survey of this kind since 2017 for LIS and 2014 for the Peconic. The project, funded by the U.S. Environmental Protection Agency through NEIWPCC in collaboration with the Long Island Sound Partnership (LIS Partnership) and the Peconic Estuary Partnership (PEP), collected new high-resolution aerial imagery and underwater video surveys during the summer and fall of 2024. Since 2002, eelgrass meadows in the Long Island Sound have been intermittently monitored through aerial surveys and field observations. These surveys provide valuable insight for resource managers into the distribution of eelgrass habitat and how it changes over time.

Eelgrass (Zostera marina Linnaeus) is a common SAV species found in shallow subtidal environments of LIS and PEC. Eelgrass, and other underwater grasses such as widgeon grass (Ruppia maritima), form underwater meadows or beds that provide essential nursery habitat for fish and shellfish, stabilize sediments, improve water quality, and sequester “blue carbon.” Blue carbon refers to carbon dioxide that is captured and stored in coastal and marine ecosystems. Both the LIS Partnership and PEP Comprehensive Conservation and Management Plans highlight eelgrass as a species of critical concern. Because eelgrass is highly sensitive to water clarity and nutrient conditions, its distribution serves as a vital indicator of estuarine health.

Footage of an eelgrass meadow captured during the underwater video analysis. Credit: University of Rhode Island and the US Fish and Wildlife Service.

Following National Oceanic Atmospheric Administration (NOAA) Coastal Management protocols and an approved EPA Quality Assurance Project Plan, both true color and infrared aerial photography were captured over the two estuaries in June and July. Field crews then collected underwater video surveys in September and October using GPS-linked cameras to validate eelgrass locations.

Analysts used Esri ArcGIS Pro software to interpret eelgrass beds from ortho-photography (aerial photographs that have had the distortion removed), incorporating field data and historical maps. More than 8,000 underwater video points informed the delineation of hundreds of SAV polygons – shapes drawn on digital maps that outline where SAV was observed – with an overall mapping accuracy of 84%. This process of capturing true-color aerial imagery over a large region and then interpreting images by eye with the aid of mapping software is referred to as “Tier 1” mapping. This mapping technique is part of a widely accepted seagrass monitoring framework that is used for quantifying the area and distribution over large regions.

In the Sound, 2,041 acres of eelgrass were mapped across 261 individual polygons, with the largest eelgrass meadow spanning 179 acres in Groton-Long Point, Connecticut. A comparison of the 2017 and 2024 LIS mapping found a net gain in eelgrass presence of 473 acres. Meanwhile, 800.6 acres of eelgrass were mapped across 112 individual polygons in the PEC. Here, the largest eelgrass meadow covers 132.8 acres and is located off Shelter Island in Coecles Harbor, New York.

Publicly accessible interactive maps, aerial imagery, and data are now available through Esri’s ArcGIS Online platform using the following links:

Regular Tier 1 assessments, ideally every one to three years, help track the recovery and resilience of these valuable underwater habitats, ensuring that managers and restoration partners can make informed decisions to protect and restore eelgrass meadows. The full report is available here and on the NEIWPCC Resource Library.

The article originally appeared on the NEIWPCC website in November 2025.

Media Contacts:

Map showing the locations of the 14 projects awarded support through the second round of the LIS Resilience Planning Support Program. Nine New York projects are shown with purple markers and five Connecticut projects with teal markers.

Soundwide (Nov. 7, 2025) Fourteen coastal communities in the Long Island Sound region have been awarded $909,121 in planning support to advance resilience-focused projects through the second round of the Long Island Sound Resilience Planning Support Program. The program is a collaboration of New York Sea Grant (NYSG), Connecticut Sea Grant (CTSG), and the Long Island Sound Partnership.

The Long Island Sound (LIS) Resilience Planning Support Program was launched in October 2023 by a team of NYSG and CTSG Sustainable and Resilient Communities (SRC) Extension Professionals who are focused on developing resources and tools to assist Long Island Sound communities in achieving their sustainability and resilience goals. The Program aims to address a major barrier that many communities face: a lack of capacity and resources to identify, conceptualize, and develop resilience projects to respond to changing environmental conditions. Participating communities are matched with qualified contractors to assist them with assessing local environmental risks, conceptualizing project ideas and conducting preliminary planning efforts to prepare for future funding opportunities that support project design and implementation. No match is required from the communities. The Program is funded by the US Environmental Protection Agency (EPA) through the Long Island Sound Partnership. 

This year’s 14 awarded projects—nine in NY and five in CT—include community resilience plans, shoreline adaptation plans, strategic plans, natural resource inventories, watershed management plans, and development of stormwater remediation strategies and conceptual design plans. Find more details below and view the full Award Slate at: www.lisresilience.org/planning-support-program-awards.

A third round of the LIS Resilience Planning Support Program will open in early December 2025, with up to $1.5 million available. Interested communities can learn more during the LIS Resilience Planning Support Program session on Friday, December 5, 2025, part of the upcoming 4th Annual SRC Workshop. This session will highlight projects completed from the 1st Round of the LIS Resilience Planning Support Program. For more information, please visit lisresilience.org/annual-workshop. 

“I’m proud to see the federal funds for which I voted last year flow to local initiatives that strengthen our shoreline and safeguard our clean water. Protecting the Long Island Sound and our coastal communities is not only an environmental priority, but also an economic and public safety imperative. In Congress, I will continue to advance these efforts by advocating for robust funding and leading bipartisan legislation to reauthorize the Long Island Sound Program through 2029—ensuring that Long Island’s clean water, healthy habitats, and climate resilience remain national priorities for years to come,” said Congressman Nick LaLota.

Congressman Joe Courtney said, “Long Island Sound and the Connecticut River are jewels of our region. As co-chair of the Long Island Caucus, I have partnered with Sea Grant to keep federal funds flowing through numerous budget cycles. This type of investment is exactly what people who care about the health of Long Island Sound were seeking to achieve. The Sea Grant team at UConn Avery Point has once again done a great job of identifying where to invest with highest value to achieve the goal of a healthy Long Island Sound, ensuring the environmental, economic, and recreational sustainability of our state.” 

“Throughout my 30-plus years in public service, I have dedicated myself to cleaning up pollution in and around the Long Island Sound, reducing nitrogen emissions from sewage treatment plants and stormwater runoff, and restoring and reseeding shellfishing beds in our harbors,” said Congressman Tom Suozzi. “Since coming to Congress in 2017, I have helped deliver a 1,000% increase in funding to improve the Long Island Sound. I am grateful for the bipartisan and collaborative efforts of many, including New York Sea Grant, the Long Island Sound Partnership, and the EPA, who have overseen significant improvements in water quality, including in Great Neck, whose award we are celebrating today. Protecting and preserving the Long Island Sound, our ‘National Park,’ is a top priority and a shared responsibility.” 

“Congratulations to all of the recipients of this year’s Long Island Sound Resilience Planning Support Program, including the Hen Island Nature Society and the Rye Sustainability Foundation,” said Congressman George Latimer. “These important investments will help protect our natural habitats and monitor the health of our ecosystems. We must continue to support projects like these through robust funding now and in the future.”

“The Long Island Sound Resilience Planning Support Program is equipping communities with actionable plans and innovative project concepts to address environmental risks and support long-term sustainability,” said New York Sea Grant Director, Rebecca Shuford. “This year we had 41 applications to the Program, underscoring the need for this important planning work. New York Sea Grant is proud to contribute to this partnership, and we look forward to seeing the positive environmental and economic benefits these projects will have locally and regionally.” 

“The impacts of this unique, match-free Program are far-reaching,” said Connecticut Sea Grant Director, Sylvain De Guise. “Through this initiative, we are building community capacity across the Long Island Sound region to address some of the most pressing challenges, including flooding and extreme weather. Connecticut Sea Grant is proud to help communities take critical steps toward achieving their resilience and sustainability goals. We look forward to supporting even more communities through the next round of the Program.”  

CT AwardeesProjectContractorAward Amount
City of BridgeportNatural Resource and Wildlife Inventory Report GEI Consultants, Inc.$39,448
Neighborhood Housing Services of New HavenStrategic Plan for a Stormwater Management Counseling Program TPA Design Group$35,000
PT PartnersEnvironmental Resilience Plan for the PT Barnum Public Housing Community and Surrounding Neighborhoods in Bridgeport, CTTPA Design Group$38,500
Town of GrotonComprehensive Green Infrastructure Community Engagement Strategy SLR International Corporation$101,300
Town of StoningtonSustainability and Resilience PlanResilient Land & Water LLC$53,800
NY AwardeesProject ContractorAward Amount
Great Neck Village Officials Association (GNVOA)Environmental Risk and Vulnerability Assessment and Adaptation PlanWoods Hole Group$99,552
Hen Island Nature Society Inc.Hen Island Shoreline Adaptation PlanEA Engineering and Geology, P.C.$78,226
Kissena SynergyFive-Year Strategic Plan for Kissena SynergyLighthouse Consulting Group, Inc.$36,148
Rye Sustainability FoundationNatural Resources Inventory Report for the City of Rye, NYBiohabitats$70,080
Salonga Wetland Advocates Network (SWAN)Conservation and Management Plan for Fresh Pond in Fort Salonga, NYGEI Consultants, Inc.$77,845
Setauket Harbor Task ForceEstablishment of a Harbor Management Model to Enhance Stewardship of the Port Jefferson-Setauket Harbor ComplexLighthouse Consulting Group, Inc.$39,543
Village of Head of the HarborConceptual Design Plans for Stormwater RemediationHayduk Engineering, LLC$58,700
Village of NorthportHarbor Walk Study and Conceptual Design PlanNV5$69,979
Village of ShorehamConceptual Design Plans for Stormwater RemediationL.K. McLean Associates $111,000

Donna Koch, Mayor and Dave Weber, Trustee of the Village of Northport, NY said, The Harbor Walk Study has the potential to shape Northport’s storm resilience for decades to come—and it would not be possible without the dedication and expertise of New York Sea Grant and the Long Island Sound Partnership. Through this resilience planning grant program, they have provided funding that our small Village could not have otherwise allocated, and for that we are truly thankful.”  

“The support we have been receiving from the LIS Resilience Planning Support Program will help us bring forward community driven solutions for a historically flood-prone area in Mystic,” said Sabit Nasir, Sustainability and Resilience Manager for the Town of Groton. “By investing in green infrastructure and engaging locally, we are not only going to address the flooding of today but creating long term resilience and a foundation for years to come, creating a better connection for residents and their natural environment.” 

“Shoreham Village is over 100 years old, and unfortunately, our drainage system and storm water management system are also 100 years old. The existing system is a patchwork of failing facilities, and the topography of Shoreham Village is much like a funnel, so even small rainfalls contribute significant pollution into the Sound. We need to modernize our stormwater management capacity,” said Edward Brickley, Stormwater Management Officer for the Village of Shoreham. “Being awarded this Planning Grant will allow us to begin the process of protecting the ecology of the Long Island Sound and to create a more resilient infrastructure to protect the properties in the Village. We view this as the critical first step and are very thankful for Sea Grant and the Long Island Sound Partnership for making it possible.”  

“The Great Neck Village Officials Association (GNVOA) is honored and pleased to be one of the awardees for a project to identify, conceptualize, and develop resilience to changing environmental conditions,” said Steven Weinberg, President of the Great Neck Village Officials Association. “Nine villages and the Town of North Hempstead make up the Great Neck peninsula. The opportunity to assess risk and to have a plan for shore restoration and flood mitigation to be adopted and implemented by the villages across the Great Neck peninsula is a vital and welcome development in intermunicipal work for all of our residents.”  

“Salonga Wetland Advocates Network (SWAN) is extremely fortunate to be included in the Long Island Sound Resilience Planning Support program. Thanks to the expertise and funding being provided by the Long Island Sound Partnership, Sea Grant and GEI, the Fort Salonga community will soon have a science-based plan to protect Fresh Pond and surrounding areas from the effects of a changing climate,” said Charlie Muller, President of SWAN. “Fresh pond is a thriving wildlife habitat and valued recreational and scenic asset in the local community.” 

“Rye Sustainability Foundation is thrilled to receive this award from the Long Island Sound Resilience Planning Support Program,” said James Ward, City of Rye Council member and Rye Sustainability Foundation Co-Founder/Director.. ”This support will allow us to refresh the City of Rye’s Natural Resources Inventory which was originally created in 1979. The new NRI will serve as a baseline for future planning efforts and resilience projects. It will also be incorporated into our Comprehensive Plan that kicks-off in early 2026. Thank you, New York Sea Grant and the Long Island Sound Partnership!” 

“We are pleased to have our resilience planning grant submittal accepted for funding,” said George Hoffman, Co-Founder and Trustee of Setauket Harbor Task Force. “A major goal of the Setauket Harbor Task Force was to fund a comprehensive look at how the various stakeholders and municipal entities manage the Port Jefferson harbor complex and provide new strategies for effective and cooperative management.” 

“We are grateful for the planning support that we have received from Connecticut Sea Grant and the Long Island Sound Partnership,” said Neighborhood Housing Services of New Haven. “Through this support, we aim to establish a stormwater counseling program that will promote the development of stormwater infrastructure on private properties in Connecticut’s key coastal urban watersheds, thus reducing nonpoint source pollution from flowing into our local waterways and the Long Island Sound. Our target communities will enjoy the benefits of a healthier aquatic environment while playing an important role in its improvement.” 

“Our Village of Head of the Harbor rises above the waters of Stony Brook Harbor and, as a result, we serve as a channel for stormwater runoff into the Harbor. This results in the degradation of the water quality of Stony Brook Harbor and Long Island Sound, as well as severe damage to our roads. Many of our local roads were built by simply paving over dirt carriage paths, and they cannot withstand the impact of stormwater rushing towards the Harbor, said Michael Utevsky, Mayor of Head of the Harbor, NY. “We are hopeful that the new grant from NY Sea Grant and Long Island Sound Partnership will help us find long-term solutions to these problems and result in more stable roads and cleaner waters.”

“The Town of Stonington is grateful for the support and funding provided through the Long Island Sound Resilience Planning Support Program,” said Danielle Chesebrough, Stonington First Selectman. “We look forward to collaborating with Resilient Land & Water to develop a comprehensive, town-wide Sustainability and Resilience Plan that unifies existing resiliency initiatives, identifies data gaps through robust community engagement, and prioritizes projects for implementation. This plan will help Stonington better understand current conditions and future risks related to sea level rise, severe storms, stormwater management, and tideland preservation. It will also establish a clear framework for addressing these challenges. Together, we are advancing a stronger, more resilient, and sustainable future for our community.” 

For more information, please visit www.lisresilience.org or direct questions by email to LISResilience@gmail.com

### 

About the Long Island Sound Partnership

The Long Island Sound Partnership, established by EPA and the states of Connecticut and New York in 1985, brings together federal and state agencies, local governments, communities, universities and industry to protect and care for the health of the Sound and its connecting rivers and bays.

For more information, visit lispartnership.org 

About New York Sea Grant

New York Sea Grant (NYSG), a cooperative program of Cornell University and the State University of New York (SUNY), is one of 34 university-based programs under the National Oceanic and Atmospheric Administration’s National Sea Grant College Program. Since 1971, NYSG has represented a statewide network of integrated research, education and extension services promoting coastal community economic vitality, environmental sustainability and citizen awareness and understanding about the State’s marine and Great Lakes resources.

Learn more at nyseagrant.org 

About Connecticut Sea Grant

Connecticut Sea Grant (CTSG), based at UConn’s Avery Point campus in Groton, is one of 34 Sea Grant programs supported by the National Oceanic and Atmospheric Administration in coastal and Great Lakes states that encourage the wise stewardship of our marine resources through research, education, outreach and technology transfer.

Learn more at seagrant.uconn.edu 

Municipal officials leading the resilience project in the Mystic section of Groton are, left to right, Sabit Nasir, sustainability and resilience manager; Johathan Reiner, director of planning and development services; Alexis Torres, sustainability and resilience specialist; Geoff Foster, town engineer; and Dave Prescott, planner II/floodplain manager. They are standing at a public access area in a neighborhood that borders the Mystic and is susceptible to flooding.
Municipal officials leading the resilience project in the Mystic section of Groton are, left to right, Sabit Nasir, sustainability and resilience manager; Johnathan Reiner, director of planning and development services; Alexis Torres, sustainability and resilience specialist; Geoff Foster, town engineer; and Dave Prescott, planner II/floodplain manager. They are standing at a public access area in a neighborhood that borders the Mystic and is susceptible to flooding.

Each year the Long Island Sound Partnership develops a work plan as part of the National Estuary Program. The work plan describes the activities conducted with EPA funds to help achieve the goals of the LIS Partnership’s Comprehensive Conservation and Management Plan. The 2025 Work Plan covers LIS Partnership activities planned with 2025 federal funds that will be conducted from Oct. 1, 2025 to Sept. 30, 2026 (fy26). It also highlights projects that were undertaken from Oct. 1, 2024 to Sept. 30, 2025 (fy25) with 2024 federal funds.

The 2024 Year in Review issue of Sound Update highlights some of Long Island Sound Partnership’s projects and achievements from 2024. This issue includes stories about the development, the Long Island Sound Community Impact Fund, and the new Long Island Sound School Network.

Aug. 12, 2025 FOR IMMEDIATE RELEASE
More information: Nancy Balcom, Connecticut Sea Grant associate director, Nancy.balcom@uconn.edu

A survey of more than 3,700 Connecticut and New York residents shows the majority view Long Island Sound as a major asset to the quality of life and economy of the region.

The survey by Connecticut Sea Grant on behalf of the Long Island Sound Partnership was conducted in 2024, 18 years after the first public perceptions survey of the estuary was completed. Survey respondents are residents of the Long Island Sound (LIS) watershed—the land area that drains into the estuary—who are a representative sample of the regional population. Nearly 9 million people live in the LIS watershed.

“General impressions of Long Island Sound are overwhelmingly positive,” said project manager Nancy Balcom, associate director of Connecticut Sea Grant. “Sixty percent of respondents agreed that ‘being near Long Island Sound makes [them] feel peaceful and happier.’ Sixty-one percent said the Sound provides recreational opportunities, 58 percent said it has a positive economic impact on the region, and 60 percent would call Long Island Sound ‘a national treasure.’”

Several questions from the 2006 survey were repeated in 2024 for comparison. For example, they were asked, “From a public health perspective, how safe do you think it is for adults and children to swim in Long Island Sound?” Sixty percent said they view the water as very safe or somewhat safe for swimming, while 26 percent believe it is somewhat unsafe or very unsafe. While still high from a public health perspective, 26 percent is an improvement over the approximately 38 percent who felt that way in 2006. Further, in the 2024 survey, 54 percent of residents said they felt it is safe to eat fish and shellfish from Long Island Sound, while 25 percent believe it is unsafe and 21 percnet were not sure. In 2006, about 41% of those surveyed felt it was unsafe to eat the Sound’s fish and shellfish.

The earlier survey was undertaken by the Stony Brook University Center of Survey Research for the Long Island Sound Study (recently renamed the Long Island Sound Partnership), a cooperative organization of the US Environmental Protection Agency (EPA), the Connecticut and New York Sea Grant programs and multiple state agencies and nonprofits focused on restoring and caring for the estuary. The partnership celebrated its 40th anniversary on June 20 with the release of an updated Comprehensive Conservation and Management Plan for the Sound.

Including both a survey and four focus groups, the recent survey was managed by Connecticut Sea Grant in conjunction with many local partners and the consulting firm OpinionWorks of Annapolis, Maryland. Funding was provided by the LIS Partnership and EPA.

While respondents to the recent survey expressed positive feelings about the Sound, only one-third were even aware that they live in the LIS watershed.

“There’s still work to be done here to build awareness of location and connection,” said Balcom. The survey report (https://lispartnership.org/2025/08/2024-public-perception-survey/) shares perceptions on topics ranging from water quality to access, outdoor activities to personal priorities, environmental behaviors to stewardship practices and communication preference. Feedback on renaming the Long Island Sound Study was gathered from the focus group participants.

Among the findings:

  • LIS has a positive image in the eyes of the vast majority of residents as a source of recreation and emotional uplift.
  • Convenient access remains a challenge.
  • Perceptions of water quality are mixed, but many people see it improving, especially in the densely populated western Sound region which for many years was plagued by the low oxygen condition known as hypoxia. Hypoxic events have steadily declined in recent years, largely the result of upgrades in sewage treatment plants that empty into the watershed.
  • While most residents understand that the actions of people on land affect the Sound’s health, more work is needed to encourage individual actions that collectively make a positive difference.

“The Long Island Sound Comprehensive Conservation and Management Plan (CCMP) includes a new goal for an Informed and Engaged Public, which focuses on inspiring the public to appreciate, value, and protect Long Island Sound,” said Nicole Tachiki, acting director of the EPA Long Island Sound Office. “Understanding current public perception is the first step in considering how we increase appreciation of the Long Island Sound. These survey results provide a basis for making improvements and assessing our goals.”

The survey release is strategically timed to help guide actions to implement the new CCMP. It will provide ideas for new programming to engage and inform more Connecticut and New York residents living in the LIS watershed and help address identified critical actions outlined in the CCMP that protect and preserve the Sound for all.

This survey sample produces a margin of sampling error of no more than ±1.6 percent at the 95 percent confidence level, meaning that if every adult resident of the region had been interviewed, the actual results could be expected to fall within that margin at least 95 percent of the time.

Connecticut Sea Grant, based at the UConn Avery Point campus in Groton, is one of 34 Sea Grant programs supported by the National Oceanic and Atmospheric Administration in coastal and Great Lakes states that encourage the wise stewardship of our marine resources through research, education, outreach and technology transfer.

The news release was written and distributed by CT Sea Grant on Aug. 12, 2025.

flyer for the aug. 16 40th anniversary events.

Celebrate 40 years of collaborative conservation on August 16 with the Long Island Sound Partnership. The program, formerly the Long Island Sound Study, marks its 40th anniversary with events events in Connecticut, New York City, and Long Island. Each will include a boat ride to commemorate the Partnership’s start on Aug. 15, 1985 when EPA, the states of Connecticut and New York toured areas of the Sound on a research vessel and announced a $1 million research grant to study pollution and water quality problems plaguing the Sound. The initiative led to the formation of the Long Island Sound Study, which changed its name to the Long Island Sound Partnership this June.

Besides the boat trip, each location will feature hands-on science activities, arts and crafts, and games. All events are from 10 am to 2 pm, include free lunch and desserts, and are free and open to the public. Some activities, including boat rides, require advance registration.


Southeastern Connecticut

Location: UConn Avery Point
Address: 1084 Shennecossett Rd, Groton, CT 06340
Highlights: Boat trips with Project Oceanology, touch tanks (from Mystic Aquarium), science stations, games, art, and more
Register here


The Bronx

Location: SUNY Maritime
Address
: 6 Pennyfield Avenue, Bronx, NY 10460
Highlights: Boat trip aboard Sea Lab 41, oyster exploration, art activities, raffle prizes, and more.
Register
here.


Nassau County

Location: The Waterfront Center
Address: 1 West End Ave., Oyster Bay, NY 11711
Highlights: Boat rides aboard the Ida May, seining, fishing lessons, arts and crafts, morning beach cleanup, and more.
Register here.

The Long Island Sound 2024 Public Perceptions Research Study was developed and conducted for Connecticut Sea Grant and the Long Island Sound Partnership to assess residents’ perceptions, knowledge, attitudes, and behaviors related to the Sound.

This comprehensive study consisted of a representative survey of 3,709 residents of Connecticut and the portions of New York State within the Long Island Sound watershed, conducted between June and August 2024, and four focus groups held in October 2024 and January 2025 to better understand important issues that emerged from the survey. This research was developed and conducted in close collaboration with the sponsors by OpinionWorks of Annapolis, Maryland.


Taken together, these two research phases provide a thorough analysis of public perceptions of the Sound, residents’ connections to the Sound and nearby waters, and their interest in and willingness to become more engaged with both the enjoyment and the restoration of Long Island Sound.

The focus groups also provided feedback on whether to rename the program from the Long Island Sound Study. Based on this input, the program was renamed the Long Island Sound Partnership in June 2025. Because the survey and report production began before the name change, the report refers to the Long Island Sound Study rather than our new name, the Long Island Sound Partnership.

Resources Describe Causes of Low Levels of Oxygen & What Scientists are Doing to Breathe New Life into the Sound

a graphic illustration of what causes hypoxia
A graphic illustration on what causes hypoxia–one of the new resources in the Hypoxia Toolkit. Illustration by Lucy Reading-Ikkanda for the LIS Partnership.

What is Hypoxia and Why Does It Matter?

Ever felt short of breath after a workout? That winded feeling – like you’re not getting enough oxygen – is called hypoxia.

The same thing can happen underwater. Fish, shellfish, and other marine animals depend on oxygen in the water to survive. When oxygen levels drop, it can mean life or death.

Every summer, parts of Long Island Sound become hypoxic. This condition can drive fish away, harm or kill stationary bottom-dwellers, and disrupt the ecosystem. It’s often referred to as an invisible sign of water pollution because you can’t see it. During extreme hypoxic or anoxic events, there may be large fish kills, which are obvious. But more often, people won’t see the impacts of hypoxia in our waters.

That doesn’t mean we won’t feel the effects, however. Hypoxic events can affect where fish go, how they grow, and their ability to reproduce. These changes can impact fishing success and, ultimately, what ends up on local tables.

Additionally, prolonged exposure to hypoxia can lead to mass mortality in shellfish populations. Shellfish like mussels, oysters, and clams are tolerant of brief periods of low oxygen, but are especially vulnerable to prolonged periods because they can’t escape low-oxygen areas. In 2021, commercial shellfishing in Connecticut brought in over $20 million. When shellfish populations decline, it hurts local harvesters and can drive up prices for consumers.

Hypoxia Toolkit: New Communications Tools to See the Unseen

But if we can’t see it, how do we know it’s there, and more importantly, where it’s going to be? That’s where our new hypoxia StoryMap and public education toolkit come in. These communication tools can help people across the region better understand what’s happening under the surface. Developed with scientists at EPA and partners across the Long Island Sound Partnership, the toolkit brings together the latest data, visuals, and explainer content – including a hypoxia forecasting tool, an animated video, and more.

These resources make it easier than ever to understand what causes hypoxia, why it matters, and how science is helping us respond.

Forecasting the Future of the Sound

Still, knowing when and where hypoxia will occur has remained a challenge. That’s why scientists scoured decades of monitoring data to develop the forecasting model to predict the extent and severity of hypoxia in the Sound. For 2025, it forecasts that up to 31 square miles of bottom waters could be affected, peaking around August 15.

Even if the forecast isn’t exact, it’s a major leap forward. “This is the first year we’re using the model to forecast hypoxia in Long Island Sound, so it’s a big step forward – even if the forecast isn’t perfect,” said Cayla Sullivan, EPA Habitat and Reporting Coordinator for the Long Island Sound Partnership, and the coordinator in developing the forecast. “The data we gather this season will help us refine the model and improve its accuracy in the future. Each year, we’re getting closer to understanding, and predicting, how hypoxia develops in the Sound.”

And why does that matter? Because better forecasting enables better decisions for resource managers, fishermen, shellfish growers, and anyone who relies on a healthy, productive Sound. It means knowing when and where marine life might be at risk. Making forecasts also challenges scientists to improve their models.

Together, the resources in the toolkit give us new tools to protect life in the Sound and adapt to a changing environment.

We may not be able to see hypoxia, but with tools like these, we can see it coming, and do something about it.

The toolkit is available in the Reduce Nutrients section of the LIS Partnership website.

Larissa Graham, education coordinator for the Connecticut National Estuarine Research Reserve, describes the importance of Bluff Point State Park, part of a LIS Stewardship area and a CT NERR site, to the LIS Partnership's Informed and Engaged Public work group.
Larissa Graham, education coordinator for the Connecticut National Estuarine Research Reserve, describes the importance of Bluff Point State Park, part of a LIS Stewardship Area and a CT NERR site, to the LIS Partnership’s Informed and Engaged Public work group.

The Long Island Sound Partnership has announced a new Stewardship Strategy to support the Long Island Sound Stewardship Initiative and its 33 designated Long Island Sound Stewardship Areas.. The Initiative, established in 2006, designated the 33 areas, 17 in Connecticut and 16 in New York, of land and water with outstanding or exemplary scientific, educational, or biological value for protection, management or acquisition. Since 2005, the Partnership has invested a total of $35 million in protecting and restoring habitat, educating the public, and improving access at the different Stewardship Area locations. The development of the Stewardship Strategy reemphasizes the Partnership’s commitment to the Initiative through a series of recommendations driven by the Stewardship Areas’ current challenges, needs, and priorities.

Over the past year, LIS Partnership staff met with Stewardship Area managers to identify challenges, needs, and priorities, which are summarized in the strategy and categorized by the Partnership’s 2025 Comprehensive Conservation and Management Plan goal to identify connections and drive future implementation. Priorities include improving water quality, filling in data gaps through monitoring and research, restoring and protecting important habitat, increasing coastal resiliency, ensuring adequate staffing capacity, improving education and outreach programs, and supporting public access.

The recommendations, derived from Stewardship Area manager discussions, aim to identify, protect, and enhance upland sites within the Long Island Sound ecosystem with significant ecological, educational, open space, public access, or recreational value. Recommendations include developing a Stewardship Network to provide a platform for the site managers and partners to collaborate and communicate on initiatives, projects, and lessons learned; establishing a framework to address existing site-specific challenges, priorities, and needs; revamping a process to identify and add new Long Island Sound Stewardship Areas; and enhancing education and outreach about the Stewardship Initiative. In particular, by developing a network, the Long Island Sound Partnership and Stewardship Area managers and their partners can work together to strengthen partnerships and address site-specific challenges, needs, and priorities to better protect and restore the Sound.

The Partnership recognizes the ecological importance of these sites, their benefits to surrounding coastal communities, and the need for long-term sustainability of investments. Through this strategy, the Long Island Sound Partnership reaffirms its commitment to sustaining viability of Stewardship Sties, by strengthening collaboration, leveraging additional resources and expanding stewardship efforts. The expected outcomes of this network are to increase acres of habitat restored and protected, strengthen community resiliency, and ensure investments last for generations to come.

The Stewardship Strategy is available in the media center of the LIS Partnership website. Information about each of the LIS Stewardship Areas is available in the Long Island Sound section of the website.

Cover page of the Long Island Sound Stewardship Strategy

The Stewardship Strategy seeks to leverage the potential strength of the network of 33 Stewardship Areas in the Long Island Sound coast that were identified in the 2000s as having outstanding or exemplary scientific, educational, or biological value for protection, management or acquisition. The development of the Stewardship Strategy lays the foundation for building this network by summarizing the site-specific challenges, needs, and priorities at each of the Stewardship Areas, identifying approaches to enhance the collaboration and communication among the managers and partners, and establishing a framework for action to support key priorities and address existing challenges and needs. 

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