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Skiing the Greener Slopes

Zachary Lehmann

Every year I pack up my ski gear and head out for a few days of fun in the snow with my friends. After a long weekend of skiing, and a couple ice-cold beverages, my friend asked me “what is the impact of ski resorts on local and regional ecosystems?” While work is usually the last thing on my mind when carving up the slopes, I made an exception this once to provide a crash course in sustainability.

snow cannons at work

Many resorts have had to increase the amount of artificial snow produced to offset warmer temperatures. Photo courtesy of Wongm.

I love skiing, but ski resorts can have a substantially negative effect on the environment. Keeping trails open and covered in snow can consume enormous amounts of energy and water. Telluride alone uses approximately 80 million gallons of water a year to keep the slopes white and the skiers happy. Powering the pumps to get the snow up the mountain, keep the lifts running, and the lodges warm also requires a lot of electricity. Jiminy Peak spent about $635,000 on electricity annually in 2009, and that’s a relatively small mountain with only nine lifts in operation (compared to larger resorts like Vail with over three times as many). When you begin to look at the ski hill in a more critical light, you start to see that our exploitation of the natural landscape is at work even when we’re on vacation.

But, this sad news is not without a silver lining. Many resorts are already well ahead of the curve with regards to getting their mountains back into the green. Smugglers’ Notch in Vermont took it a step further and focused on eco-education and wildlife habitat protection efforts. All ski classes stop by the Mother Nature eco-teacher to teach new skiers about their impacts on the environment and what they can do to minimize them. Park City in Utah has reduced their amount of greenhouse gas emissions by over 15,000 tons.

turbines ski resort

Aspen and Jiminy Peak aren’t the only resorts to use wind turbines to offset electrical demands. Naetschen in Switzerland has also invested in wind power. Photo courtesy of Sas1998.

Aspen started their eco initiatives back in 1997 and have become the first ski resort to offset 100% of its electricity with a number of large wind turbines and by patching into solar and wind power plants. Their vehicles and groomers also run on biodiesel and they have the largest solar power generation system in the industry. They have become the example all other mountains try to follow. Even Jiminy Peak has gotten into the mix, installing a massive wind turbine on its mountain which contributes 33% of the electrical demands of the resort.

A telemark skiier cuts through fresh powder. Photo Courtesy of Timuzapata.

While the ski industry as a whole has a long way to go, it is exciting to see a lot of the resorts, both big and small, taking serious strides to minimize their impact on the environment. So the next time you hit the slopes, make sure to take a minute and check to see if the resort is doing all it can to preserve the global climate you need to enjoy skiing for years to come. I for one can sleep better knowing my beloved K-1 Gondola at Killington runs on 100% renewable energy.

About the Author

Zak LehmannZachary Lehmann has over six years of experience as a field biologist and GIS specialist in New York City and the surrounding wetlands. He specializes in wetland delineation, wildlife and plant inventory and monitoring, with a focus on bird and mammal species.


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Great Ecology’s Local Project Featured in La Jolla Light

Great Ecology is featured in the La Jolla Light Newspaper highlighting conceptual designs created for the La Jolla Whale View Point Shoreline Enhancement project.

Great Ecology’s interdisciplinary team of designers and ecologists were excited to develop conceptual restoration plans for the 20-year coastal restoration project in La Jolla, CA. The La Jolla Light Newspaper featured the Whale View Point Shoreline Enhancement initiative and Great Ecology’s ecological approach to managing the problem of coastal erosion. Great Ecology was engaged by the non-profit, La Jolla Parks and Beaches (LJPB) foundation to examine on-site urban stormwater capture and management, coastal erosion, public access, and interpretive signage.




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Great Ecology at EUEC

Great Ecology is excited to join the Energy, Utility, and Environment Conference (EUEC) this week, February 16-18 in our hometown, San Diego.

President, Dr. Mark Laska is leading a session, Remediation, Ecological Design, & Mitigation, and the panel promises to present interesting ideas and approaches. The panel presentations include:

  • Framework For Ecological Re-Use Of Disturbed Ecosystems
  • A Greener Shade Of Brownfields – A Corporate Perspective
  • A Case Study Of Wetland Mitigation In A Heavily Industrialized Waterfront
  • Private Capital Investment In Large Scale Restoration
  • Restoration Of Impaired Ecosystems: An Ounce Of Prevention Or A Pound Of Cure

EUEC attendees, come meet our local San Diego team  – we’ll be at booth 507!

EUEC 2015 Panel & Staff

Great Ecology staff members and panel comprised of representatives from Chevron, Kinder Morgan, and Ecosystem Investment Partners.













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Navigating Over the River: Weighing the Impacts of Art in the Landscape

Chris Loftus, RLA, ASLA

It’s an intriguing vision: miles of luminous sliver ribbon suspended over a wild river, bending light and accentuating canyon curves. First conceived by the artist Christo and his late wife Jeanne-Claude in the early nineteen-nineties, the Over the River (OTR) project proposes to suspend 5.9 miles of silver fabric in eight distinct locations along a 42-mile stretch of the Arkansas River in South-central Colorado.

Over the river trial run

A field test completed in 1999 shows how OTR could look from below the fabric. This image was published in the Environmental Impact Statement issued in 2011.

The path to realization of OTR has been as curvilinear and dynamic as the river over which it is proposed. Years of analysis and thousands of pages of permitting documents, multiple state and federal law suits, and a flurry of public opposition have extended the project’s timeline and still obstruct the announcement of an installation date. Once initiated, the project would take 27 months to implement and would be displayed for a two-week period during the month of August.

Impacts to the ecosystems along the Arkansas’ riparian corridor present one of the most contentious aspects of the project. The proposed installation includes a fabric and cable system anchored to the canyon walls and river banks, which could create temporary obstacles to wildlife movement and altered microclimatic conditions. The entire project area is under Bureau of Land Management (BLM) jurisdiction, and an Environmental Impact Study (EIS) was completed as part of the permitting process. The EIS describes a number of mitigation measures that address terrestrial, avian, and aquatic wildlife and habitat impacts. These measures include the provision of access to previously unavailable bighorn sheep habitat, the establishment of a bighorn sheep adaptive management fund for future mitigation efforts, creation of raptor nest buffers, preservation of all existing trees in the area, and sedimentation prevention to protect instream habitat. The project implementation schedule was also designed to minimize impacts during especially sensitive seasonal wildlife activity.


A map of the proposed project area which spans 42 miles of the Arkansas River in 8 distinct locations.

Following the 2011 BLM Record of Decision approving the project, multiple legal obstacles surfaced. Recent litigious action and associated publicity have rekindled public interest in the project. On January 2, 2015, a federal judge upheld the BLM’s decision to allow the installation. Another federal appeal was filed on January 26, continuing to delay final permitting and project commencement. On February 12, OTR cleared a state hurdle when the Colorado Court of Appeals ruled to uphold a 2013 decision in favor of Colorado State Parks’ approval of the project. The most visible and organized public and legal opposition has originated from Rags Over the Arkansas River, or ROAR, which has fought the project at local, state, and federal levels. ROAR cites potential negative impacts to local communities and wildlife as grounds for blocking the proposal.

Jeanne-Claude_and_Christo_(1995) Reichstag

Christo and his late wife Jeanne-Claude. Taken outside of the Reichstag in Berlin, the location of one of their famous”wrapped” art pieces.

Christo, who has successfully completed other large scale projects around the world including the Gates installation in Central Park and a previous Colorado installation called Valley Curtain, seems unfazed by the ongoing opposition. His comments indicate that he considers it a valuable part of the process for projects of this scope. In a 2013 Denver Post interview, Christo remarked, “For many years, all the people are thinking how the work will be beautiful, how the work will be awful. Basically the work is working in the mind of the people before it physically exists. This is probably the biggest satisfaction we have.” OTR, like Christo’s other installations, is funded solely from sales of the artist’s work, including the original concept sketches.

Proponents of Christo’s work believe that it accentuates natural forms and invites people to reinvent their perceptions of the landscape. Opponents find the installations obtrusive and unnatural. Time and the legal system will determine OTR’s fate. In the meantime, the Arkansas River will continue its dynamic flow through the Rocky Mountains toward the Great Plains.

About the Author

Chris LoftusChris is a Registered Landscape Architect with over ten years of experience working in the western United States. He specializes in the reintroduction of highly functioning ecological systems to degraded landscapes.


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Great Ecology’s Top 5 Must Watch TED Talks

Erin Hathaway

TED Talks are a wonderful resource to hear the world’s thought leaders discuss their passion and research. We’ve picked our top five TED Talks that take a deeper look into the field of ecological restoration – some new ideas, some old with new applications, but all well worth watching.

Eric Sanderson: New York – Before the City

Why: Sanderson’s passion for uncovering New York City’s historical ecologies reminds us all to be conscious of what came before and how much we impact the landscape. Sanderson’s talk resonates with our staff because on September 10th 2001, Great Ecology started in a tiny office space in Manhattan. Great Ecology’s employees, based in large urban centers including New York City, Denver, and Sacramento are inspired by the surrounding urban landscape and the potential to restore what once inhabited the waters and soil.

Shubhendu Sharma: How to grow a tiny forest anywhere

Why: Sharma’s talk encourages viewers to think about habitat from a production value perspective. By applying industrial techniques and the lean manufacturing principles developed by Toyota, Sharma has developed a process to create forests which grow 10 times faster and are 100 times more biodiverse.  A tiny, yet complex, forest functions extremely efficiently and offers many benefits reminding us that quality is often better than quantity.

Allan Savory: How to fight desertification and reverse climate change

Why: The practice of landscape ecology is constantly evolving to serve changing conditions, new technologies, and innovative thinking. Savory dedicated his life to remediating the harmful effects of desertification, and he shares how managed livestock grazing can be integral to restoring grasslands across the world. Savory’s story reminds us to challenge the status quo, take risks, and find sustainable solutions.

Pavan Sukhdev: Put a Value on Nature!

Why: Natural assets are often overlooked and undervalued. Sukhdev discusses the several trillion dollar value of natural capital across the world. As restoration ecologists, we look for ways to increase ecological function, maximize the value of natural assets, add economic value, and introduce public access.

Rob Harmon: How the market can keep streams flowing

Why: This is an incredible story about how partnerships can be formed with businesses to be mutually beneficial and provide ecologically guided solutions. The ecosystem marketplace is just beginning to take shape and we see it moving to the forefront of conversations in government, industry, and environmental organizations.

These are just a few of our favorite TED Talks which highlight the increasing trend of ecological guided solutions to land use, management, and restoration. Do you have any favorite environmental-focused TED talks? Share them!

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Dr. Mark S. Laska: Most Admired CEO Award Finalist

We are thrilled to announce Great Ecology President & CEO, Dr. Mark S. Laska, is recognized as a Most Admired CEO Award Finalist by the San Diego Business Journal. This annual awards program recognizes outstanding CEO’s in the San Diego region who contribute to the company’s financial success and growth through innovative leadership practices, demonstrate exceptional community involvement and philanthropic contributions, maintain a positive work environment, and empower and inspire others.

SDBJ Most Admired CEO

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Great Ecology Featured in Green Build & Design Magazine

Great Ecology is proud to be featured in the recent issue of the  Green Build & Design Magazine. The article, Ground Swell, highlights the new Corktown Common Waterfront Park, a post-industrial site along the Toronto waterfront. Collaborating with Michael Van Valkenburgh Associates Inc. Great Ecology supported the restoration of the native habitat and ecology. The project creates wetland and upland wildlife habitats infused with a cultural and ecological public space along the Toronto waterfront.

Corktown Common Waterfront Park

A Glimpse at Corktown Common Waterfront Park in Toronto. The new public space supports wetland and upland wildlife habitat along Toronto’s post-industrial waterfront.


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Climate Change Models – Why Buying Beachfront Might Not be Your Best Bet

Marlene Tyner, M.E.S.M. 

The New York Times recently urged everyone to pull up their New York, San Diego, and Miami roots and move on over to Portland, Seattle, and Detroit. Why the incitement to mass-migration? Climate change.

In an article published in the journal Nature, climate change researchers concluded that in a warmer future, several American cities will be losers (higher temperatures, drought, sea level rise), and some will be winners (moderate climate, reasonable precipitation, consistent shorelines). Because climate models contain both spatial and temporal variables, they can be mapped. And as a result, the authors found that some parts of the United States will feel the impacts of climate change more than others.

Sea Level Rise can really lengthen your morning commute. Photo courtesy of Marvin Nauman.

Sea Level Rise can really lengthen your morning commute. Photo courtesy of Marvin Nauman.

But, before you sell your beachfront Miami home and move to Milwaukee, it might be useful to ask: How accurate are these predictions anyway? To answer that question we need to understand how these predictions were generated and how to interpret them.

General Circulation Models
General Circulation Models (GCMs) are the models used by climate scientists to generate global climate change predictions. There are a ton of these models out there, developed and run at institutions as wide-ranging as the U.S. National Centre for Atmospheric Research, the Russian Institute for Numerical Mathematics, and the Korean Meteorological Administration. In total, approximately 80 GCMs from across the globe were evaluated for the Intergovernmental Panel on Climate Change’s (IPCC) Climate Change 2013 Report.

GCMs attempt to mimic the global climate, a complex system influenced by the way the atmosphere, land, sea-ice, and ocean behave and interrelate. Climate modelers apply basic laws of physics to each individual component of the earth system, and then use those same laws to link all the systems.

Each GCM differs in both the equations used to approximate physical processes in these systems, and how the equations are parameterized, or what values can be plugged into the model. You may see model results reported under different ‘scenarios’ – that just means that they’ve run the models using varying levels of carbon dioxide (CO2) emissions to see how the climate will be behave in a world filled with the same or more CO2.


Climate models are systems of differential equations based on the basic laws of physics, fluid motion, and chemistry. To “run” a model, scientists divide the planet into a 3-dimensional grid, apply the basic equations, and evaluate the results. Graphic & caption courtesy of NOAA.

GCMs are run on computers, which read and process data in globe-sized grids. Think of the pixels on photos or your TV screen, but bigger (~40 square miles per cell) and covering the entire world. The various component models are layered on top of each other on this grid, and the computer calculates a target value for each grid cell. If scientists were interested in temperature, for example, they would output the average temperature in each cell across the globe. You can run GCMs multiple times in succession to approximate how temperature might change over time, with each run representing a month, or a year, etc. This works because the models reference back to the previous time step for many of their parameters. The temporal aspect of climate models allows scientists to make temperature and other variable predictions based on various climate starting-points.

That’s partly why GCMs are run under different climate change scenarios. These scenarios represent approximations of variables in the environment that will be different in the future and by how much. The standard today is to use Representative Concentration Pathways (RCPs), which describe greenhouse gas concentration trajectories and their effect on how much of the sun’s energy gets trapped between the Earth’s surface and the atmosphere. A higher RCP indicates a warmer future, with the hottest scenario denoted as RCP8.5 by the IPCC. Running different scenarios allows us to understand what the Earth will look like in the future based on the actions we take today, such as reducing greenhouse gas emissions.

So how robust are climate change model predictions?

Satellite observations align with the most extreme IPCC predictions of sea level rise, which were generated by running several GCMs using historical data, Graph source:

Satellite observations align with the most extreme IPCC predictions of sea level rise, which were generated by running several GCMs using historical data. Graphic courtesy of The Copenhagen Diagnosis.

One way is to use a data comparison method known as hindcasting. When you hindcast, you’re really matching model projections of past climate variables, such as sea level rise, with observed data (see sea level rise graph). This allows you to see how good your model is at generating the same climate data as what we already observed long ago.

Another way is to run the model multiple times under the same climate scenario(s) to account for any variation in predictions. The figure below shows temperature observations in black, model temperature predictions in yellow, and the average of the model predictions in red. See how close the red average predicted value tracks the observed values in black?

Global mean near-surface temperatures over the 20th century from observations (black) and as obtained from 58 simulations produced by 14 different climate models driven by both natural and human-caused factors that influence climate (yellow). The mean of all these runs is also shown (thick red line). Temperature anomalies are shown relative to the 1901 to 1950 mean. Vertical grey lines indicate the timing of major volcanic eruptions.

Global mean near-surface temperatures over the 20th century from observations (black) and as obtained from 58 simulations produced by 14 different climate models driven by both natural and human-caused factors that influence climate (yellow). The mean of all these runs is also shown (thick red line). Temperature anomalies are shown relative to the 1901 to 1950 mean. Vertical grey lines indicate the timing of major volcanic eruptions. Graphic & caption courtesy of IPCC 2013

However, while GCMs are great at predicting long-term changes across large areas, they are limited in a few key ways. First, they don’t predict the weather, but instead show long term trends. Like the U.S. stock market, some days might be up and some might be down, but it has experienced an overall increase over the past 100 years. The same is true of CO2 concentrations and temperature. Second, there is a lot of debate over the utility of global climate models to accurately predict regional climate change due to their large spatial scale. When one square contains 40 square miles, you miss a lot of detail. However, there are different models which can facilitate regional climate analysis.

Downscaling to Enhance Regional Climate Models
Regional Climate Models allow scientists to understand the impacts of climate change at higher resolutions over specific regions, and are developed through either dynamical or statistical downscaling. Dynamical downscaling involves running a climate model using a smaller grid size, zooming in on a specific part of the Earth, and interpolating the input data to fit the new grid size. Statistical downscaling uses advanced statistics to predict smaller-scale variation in each larger grid cells using predictor variables (IPCC 2013). However, the researchers of the previously-mentioned Nature article used a novel data aggregation technique that gives a much more local understanding of climate change in a statistically robust manner. This technique could be used to generate city-specific guidelines for land-use planning, real estate development, and an understanding of which natural resources to prioritize for conservation.

So say goodbye to the beach, San Diegans, and head to the Midwest. At least the real estate prices are reasonable.

About the Author:

Marlene TynerMarlene Tyner has over 6 years of experience in ecological research and environmental analysis. Her past work includes coastal and near-shore sedimentation modeling, responses of ecosystem processes and communities to climate change, and global habitat modeling under various climate change predictions. 

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Salmon Receive Armed Support in Fight for Survival

Devin O’Dea

“All animals are equal, but some animals are more equal than others.” – George Orwell

What happens when two federally protected species go head to head over habitat and limited natural resources? Who decides which species will be saved and which species will be eliminated? These questions have begun to surface with increasing frequency as federal agencies have been forced to take drastic measures in an attempt to save critically endangered species in the Pacific Northwest.

Historical competition between species is an intrinsic component to evolution. It is a natural process that predates humanity by billions of years, and one that will persist far past human existence. However, certain anthropogenic impacts have had a caustic influence on the rate of species loss, with some estimates ascribing an accelerated rate of extinction at 100 to 1,000 times faster than the rate of species loss before human existence. Faced with these facts, federal agencies, such as the U.S. Fish & Wildlife Service (USFWS), the U.S. Army Core of Engineers (USACE), and the National Marine Fisheries Service (NMFS), have considered and in some cases piloted programs which systematically kill one federally protected species to protect another.

A Double-crested cormorant colony on East Sand Island, OR

The massive cormorant colony on East Sand Island, OR.

East Sand Island, Astoria, Oregon30,000 hungry cormorants (Phalacrocorax auritus) have gathered to feast upon the thousands of tiny coho salmon (Oncorhynchus kisutch) making the dangerous journey along the Columbia River to the mouth of the Pacific Ocean. Researchers tasked with the protection and management of salmon populations are concerned by the number of fish that never make it to the ocean, and instead end up in the mouths of the voracious cormorants. Scientists have estimated that the bird population on East Sand Island consumes approximately 25 million smolts, or 20% of all juvenile salmon and steelhead swimming down the Columbia River, and each individual cormorant can eat up to 2lbs of fish a day.

"Phalacrocorax auritus with a fish" by Brocken Inaglory -

“(Phalacrocorax auritus) with a fish” Photo Courtesy of Brocken Inaglory

The massive population of birds migrated to East Sand Island and other similar locations along river mouths of the Pacific Northwest approximately 15 years ago. Scientists believe the birds settled here due to the rebounding salmon population. Today, in a drastic attempt to save the struggling salmon population, the USACE is considering controlling (primarily through trapping & shooting) the East Sand Island bird/cormorant population by approximately 4,000 birds a year. From 2015-2018, their goal is to eliminate 2/3’s of the local population or all but 5,939 nesting pairs. This initiative has provoked a strong negative response amongst many environmental organizations and conservation groups, who argue that there are better alternatives which would benefit both species. They claim that the emphasis should instead be on the hydroelectric dams and habitat restoration. A representative of the USACE, Joyce Casey, states that the agency has “tried other methods to try to address the consumption problem and they don’t seem to be working,” Some of these methods include hazing or attempting to drive the birds away from the site, but these efforts have repeatedly failed as the birds always return to East Sand Island.

Federally Endangered Salmon leaps up waterfall.

A salmon attempting a heroic leap up a waterfall to reach spawning grounds. Photo courtesy of Edward Mcmaihin.

Anthropogenic Impacts to Habitat

Anthropogenic impacts have played a pivotal role in the modification of salmon and cormorant habitats in the Columbia River basin. Hydroelectric dams on the Columbia and Snake Rivers were primarily responsible for the decline in the local salmon population as salmon were blocked from their spawning sites and often killed by the dam’s turbines. Conversely, the cormorant habitat was actually improved by dredging activities associated with the Columbia River Channel Improvement Project which significantly reinforced East Sand Island, providing the cormorants an excellent breeding ground and habitat to rear their young. According to a study published by the Environmental Protection Agency, (EPA) “In the Columbia Basin over one-third of the habitat formerly occupied by salmon is now blocked by dams. Further, dams alter several key characteristics of water, especially temperature, dissolved gases, sediment transport, and the quantity and timing of flow.”  Many argue that because the Columbia River dams negatively impacted aquatic wildlife habitat, drastic measures are now necessary to compensate for this species loss.

Blaine Parker a fisheries Biologist for the Columbia River Intertribal Fish Commission who supports the USACE initiative, argues that tax payers who purchase hydroelectric power “have spent hundreds of millions annually to make the ecosystem more fish-friendly,” and they are not inclined to see the fish population rapidly consumed by birds. According to the USACE’s Double-crested Cormorant Management Plan “for some salmonid groups, average double-crested cormorant predation impacts can be similar to or exceed the mortality experienced at a hydropower dam in the Federal Columbia River Power System, and, in some years, can be three to four times higher.”

Federally Protected Species Targeted for Removal

Invasive barred owl threatens the species survival of the Northern Spotted Owl

The barred owl, an invasive species targeted for removal by the USFWS in order to protect the endemic Northern spotted owl.

Many groups who oppose the USACE plan made similar arguments in regards to the protection of the Northern Spotted owl (Strix occidentalis caurina), an endangered species endemic to the Pacific Northwest whose existence was threatened due to logging and invasive species. However, similar to the plight of the salmon, the conservation and protection of their habitat alone wasn’t enough, due to an invasion of barred owls (Strix varia) from the East. As a result, the USFWS approved an experiment to shoot the barred owls in an attempt to help the Northern Spotted owl recover. Shortly thereafter, the USFWS was sued by an advocacy group, Friends of the Animals, on the grounds that the Barred owls are a federally protected species under the Migratory Bird Treaty Act of 1918.


A california sea lion (Zalophus californianus), a federally protected species currently being trapped and killed to protect endangered salmon.

The USACE management plan will not be the first time endangered salmon have received preferential treatment over a predator species. In 2012 the National Marine Fisheries Service approved an initiative to trap and/or kill sea lions that were guilty of consuming salmon near the Bonneville Dam in Oregon. A decision which was also challenged in a court of law, this time in an unsuccessful lawsuit filed by the Humane Society.

The questions remain

How do we decide which species needs more protection? How do we balance the competing objectives of different species? Is eliminating one species to save another the only recourse for federal agencies seeking to bring a species back from the brink of extinction? Stay tuned for a follow up blog on New Zealand and Australia’s answer to adopt a mathematical approach to species conservation.


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Sea Level Rise – Where Do We Go From Here?

David J. Yozzo, Ph.D.

The occurrence and destructive aftermath of Hurricane Sandy, which struck New Jersey’s central/southern coast in 2012, certainly captured the attention of those who live, work and recreate along shorelines. For proponents and practitioners of ecosystem restoration projects, especially coastal wetlands, the effects of Sandy were striking.

Coastal resiliency planning and sea level rise became a major concern after the destructive effects of Hurricane Sandy

Coastal resiliency planning and sea level rise became a major concern after the destructive effects of Hurricane Sandy. Photo by Dr. David Yozzo.

While it has been recognized for decades that restored coastal wetlands are subject to adaptive modification as a result of stochastic processes, such as storm events and vessel traffic, the design of these systems has not always benefitted from forecasting the effects of sea level rise (SLR) on tidal flooding regimes and storm events over anticipated project lifetimes (i.e. 50+ years). Resource management agencies and coastal ecologists often question the value of investing considerable time, money and labor into restoring habitats at the dynamic water’s edge – will these ecosystems and the ecological and social benefits they provide persist for sufficient durations given current SLR forecasts? How should current thinking with regard to design elevations, planting schemes, and proximity to adjacent natural and engineered habitats be modified to compensate for SLR impacts, especially within estuaries surrounded by dense residential, industrial, and commercial infrastructure?

The Impacts of Rising Seas

Centuries of shoreline development and realignment have left New Jersey and other coastal land forms in jeopardy of inundation and ecological habitat loss

Centuries of shoreline development and realignment have left New Jersey and other coastal land forms in jeopardy of inundation and ecological habitat loss.

The primary impact of sea level rise on coastal environments and infrastructure is the direct loss of land and habitat from inundation. A secondary impact is the migration of coastal landforms inland (retreat). In an urban setting such as the New York/New Jersey metropolitan area, the likelihood of coastal retreat is severely restricted from centuries of shoreline development and re-alignment. An additional impact of climate change and sea level rise is the effect of increased salinity associated with rising coastal waters, ultimately resulting in the conversion of freshwater tidal wetlands to brackish salt marshes in the upper reaches of estuaries.

Piermont Marsh, lower Hudson River – common reed (Phragmites australis) is believed to have provided a defense from storm surge damage to nearby homes and other coastal infrastructure during Hurricane Sandy.

Piermont Marsh, lower Hudson River – Common reed (Phragmites australis) is believed to have provided a defense from storm surge damage to nearby homes and other coastal infrastructure during Hurricane Sandy.

Presently, the rate of sea level rise in the Hudson-Raritan Estuary (HRE) is approximately 2.7 mm/year, which exceeds the global average of 1.8 mm/year (IPCC, 2014, Needelman et al. 2012). The higher observed average rate of sea-level rise in this region is partially the result of post-glacial rebound. This exacerbates the amount of observed wetland/shoreline subsidence attributed to eustatic sea-level rise (i.e., that brought about by an increase in the volume of the world’s oceans, because of the thermal expansion) (Hartig et al. 2002). Along with increases in mean sea level, storm intensity and frequency are also predicted to increase. A shift in storm intensity towards Polar regions is anticipated under future climate change scenarios, with more frequent and damaging storms expected to occur in the north Atlantic (NWF 2011). These processes are complementary, as an increase in mean sea level will exacerbate the surge effects associated with more intense and frequent coastal storms.

Coastal Resiliency Planning

An important factor that is often ignored in forecasting the response of coastal wetlands to sea level rise is tidal range, which varies considerably along the world’s coastlines. Estuarine and coastal habitats characterized by a micro-tidal regime (tidal range of less than 2 meters) (i.e., the Gulf of Mexico) may experience the greatest effects of sea level rise, as native plant and animal communities are not accustomed to large fluctuations in inundation frequency and depth. In contrast, macro-tidal systems (4+ meter tidal range), such as the Puget Sound region of Washington or estuaries along Maine’s coast, are expected to exhibit a considerable degree of resilience to changes in sea level, as the plant and animal communities present in these systems are adapted to wide fluctuations in tides and current regimes. Meso-tidal estuaries, for example the Hudson–Raritan Estuary, are likely to exhibit a moderate degree of resilience in comparison to micro- or macro-tidal systems (Needelman et al. 2012).

Piermont Marsh, lower Hudson River – common reed (Phragmites australis) is believed to have provided a defense from storm surge damage to nearby homes and other coastal infrastructure during Hurricane Sandy.

Ribbed mussel (Guekenisa demissa) and salt marsh cordgrass (Spartina alterniflora) matrix behind dilapidated wooden cribbing in Jamaica Bay, NY. Both species function as ecosystem engineers to stabilize coastal sediments.

An additional source of uncertainty in attempting to predict the effects of climate change and sea level rise on coastal habitats within the Hudson-Raritan Estuary (and elsewhere) is the occurrence of non-linear response patterns (Needelman et al. 2012). Often, impacts to wetlands and other coastal habitats are not necessarily observed until a disturbance threshold is reached. This may explain the rapid and recent loss of salt marsh islands in Jamaica Bay, New York, a lagoon-type estuary subjected to dredging, coastal development, and wastewater inputs for several decades before exhibiting tangible degradation. Once the impact threshold was reached, perhaps in the late 1990s, the system reached a tipping point, and degradation became readily discernible. In the future, Jamaica Bay will likely continue to experience rapid erosion and/or subsidence of wetlands in the face of rising sea level. In contrast, wetlands associated with a continuous source of sediments from river drainage basins (i.e., Raritan River wetlands) may persist for a much longer duration before reaching disturbance thresholds.

Non-linear responses in coastal systems are not well-studied and future restoration programs in the Hudson-Raritan Estuary would benefit substantially from a better understanding of ecological tipping points and disturbance thresholds, especially with regard to enhancing resiliency in the face of climate change impacts.

The second edition of this two part blog series will provide an overview of ongoing restoration and management initiatives in response to SLR within the Hudson-Raritan Estuary, including living shoreline approaches, managed retreat, and the beneficial use of dredged material in coastal habitat restoration programs.


Hartig, E.K, V. Gornitz, A. Kolker, F. Mushacke, and D. Fallon. 2002. Anthropogenic and climate change impacts on salt marshes of Jamaica Bay, New York City. Wetlands 22:71-89.

IPCC. 2014. Climate Change 2014. Synthesis Report. An Assessment of the Intergovernmental Panel on Climate Change.

Needelman, B.A., S. Crooks, C.A. Shumway, J.G. Titus, R.Takacs, and J.E. Hawkes. 2012. Restore-Adapt-Mitigate: Responding to Climate Change Through Coastal Habitat Restoration. B.A. Needelman, J. Benoit, S. Bosak, and C. Lyons (eds.). Restore America’s Estuaries, Washington D.C., pp. 1-63.

NWF 2011. Practical Guidance for Coastal Climate-Smart Conservation Projects in the Northeast: Case Examples for Coastal Impoundments and Living Shorelines. National Wildlife Federation.

About the Author

Dave YozzoDr. David Yozzo is an estuarine ecologist with over 20 years of experience in academics, government, and the private sector. His professional and research expertise includes community ecology of tidal and freshwater wetlands, ecosystem functional assessment, and coastal/freshwater habitat restoration.

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