New assessment suggests that a healthy Great Bay Estuary is worth a lot to people who live here

By Kirsten Howard, New Hampshire Department of Environmental Services Coastal Program

We all know that people care about the Great Bay Estuary for a lot of reasons, whether because they boat on it, make their living from it, like to look at it, eat seafood produced in it, are protected by it, or something else. But just how much do people care about the Great Bay Estuary? Or more specifically, how much do people benefit from three of the key habitats—eelgrass, oyster beds, and salt marshes—that help make the Great Bay Estuary what it is? In a new assessment, the N.H. Department of Environmental Services Coastal Program, PREP, The Nature Conservancy, and the N.H. Department of Fish and Game Great Bay National Estuarine Research Reserve together with the National Oceanic and Atmospheric Administration (NOAA), try to answer that very question. Evaluating ecosystem services—a term for the benefits people get from nature—is a tough nut to crack, but through a collaborative process the project partners made some great progress that PREP and others hope to build on in the future.

What are the biggest benefits to people from the Great Bay Estuary?
There are lots of ways people benefit from eelgrass, oyster beds, and salt marshes. Existing surveys together with stakeholder advisory group input were used to help select a few benefits to focus on in this assessment. The project partners came up with a laundry list and narrowed down to a few ecosystem services that we have good data about: commercial fishing and aquaculture, recreational fishing and oyster harvesting, carbon sequestration (the uptake of carbon from thewater column), nitrogen removal, and the value of existence.

What could our estuary’s future look like?
Next, the stakeholder group designed two future scenarios that roughly represent what the Great Bay Estuary could look like in the year 2025. These two scenarios were intended to represent two ends of a spectrum of possible futures where our activities result in either improvements to or degradation of today’s habitats. With that in mind, the scenarios are named: “Gain and Sustain Habitats and Benefits” and “Lose Habitats and Benefit.” These scenarios took into account different configurations of activities, stressors, management actions, and restoration efforts in the Great Bay Estuary to understand what future eelgrass, salt marshes, and oyster beds could look like. The figure below shows the acreage of habitat in the Estuary currently (roughly the year 2013) contrasted against the two future scenarios. As a quick caveat, these scenarios represent hypothetical possibilities that helped the project team investigate a question; they do not represent PREP’s or any other organization’s management goals.

What did we find?
It’s no surprise that people value the Great Bay Estuary, but once you start to quantify the value that people get from various aspects of the Great Bay Estuary, things get both more interesting and more complicated.

The fact that habitats exist is worth something to people. People living in the coastal watershed value the simple existence of more habitat in the Gain Scenario compared to less habitat in the Lose Scenario by around 42 million dollars per year. That doesn’t mean the entire Great Bay Estuary is worth that amount. It means that the existence of 2,866 more acres eelgrass, 142 more acres salt marsh, and 181 more acres natural oyster beds in the Gain Scenario compared to the Lose Scenario is worth 42 million dollars (in 2015 dollars) per year to residents in the coastal watershed, regardless of whether those people ever even visit Great Bay.

If better water quality leads to new areas open for oyster harvest, oyster farmers would benefit. While oyster aquaculture permit areas are expected to expand in both scenarios, water quality improvements in the Gain Scenario could result in currently closed areas being opened to aquaculture permitting. Assuming that, by 2025 33 more oyster aquaculture acres are permitted in the Gain Scenario compared to the Lose Scenario, farmers would see additional annual revenues between $131,000 to $142,000.

If we lose most of the eelgrass in the Great Bay Estuary, Gulf of Maine commercial fishermen could lose a lot of potential revenue. Eelgrass provides habitat for small fish that feed big fish that feed people. Under the Lose Scenario, most of the eelgrass in the Great Bay Estuary disappears, resulting in 1.7 million dollars less annual revenue for Gulf of Maine commercial fishermen compared to the Gain Scenario.

What’s next?
This assessment presents only a small window into the value provided by our Great Bay Estuary. There are many other ecosystem services that we’d like to evaluate, some of which we may be able to put dollar values on and others, such as the cultural and spiritual benefits provided by Great Bay, which may be too hard to quantify. As PREP prepares for the State of the Estuary Report release later this year, this assessment reinvigorates our commitment to better understand, protect, and improve the water quality and overall health of our estuaries.
We want to ask you; how do you benefit from the Great Bay Estuary? And what do you want its future to look like?

Download Full Report HERE
For questions about the Great Bay Ecosystem Services Assessment, please contact Kirsten Howard at the N.H. Department of Environmental Services Coastal Program at

PREP is part of the U.S. Environmental Protection Agency’s National Estuary Program, a joint program between local, state and federal agencies established under the Clean Water Act with the goal of protecting and enhancing nationally significant estuarine resources. PREP is supported in part by an EPA matching grant and is housed within the School of Marine Science and Ocean Engineering at the University of New Hampshire.