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Nearshore Habitat Values Model Calculator Frequently Asked Questions

The calculator determines changes in habitat value in a common currency that represents habitat impacts as debits, and habitat improvements as credits.

Q: How will the proposed projects jeopardize Chinook salmon and killer whales?

The nearshore environment where the projects are located provides essential nursery habitat where juvenile Chinook salmon grow before they migrate to the ocean. Research shows that the larger they grow in this productive habitat, the more likely they are to survive their subsequent years in the ocean and return to rivers as adults to spawn. Most nearshore habitat in Puget Sound is gone. More than 95 percent of key tidal wetlands across South and Central Puget Sound have been eliminated, with many river deltas lost to development.

The odds of survival for juvenile Puget Sound Chinook salmon have dwindled as nearshore habitat has declined. Fewer than 1 percent of juvenile Chinook salmon that leave for the ocean typically return as adults. This is not enough to sustain the species, and some populations in South and Central Puget Sound have declined in roughly four of every five years. Southern Resident killer whales are also affected because Puget Sound Chinook salmon are one of the most important Chinook stocks that the fish-eating killer whales depend on as prey.

The availability of prey is considered one of the three main threats to the whales, which also include vessel traffic and noise and toxic pollution.

Q: How can a maintenance project that repairs or replaces a structure cause new impacts?

The replacement of existing structures or structural repairs can meaningfully extend the life of all or part of an existing structure. In these circumstances, future impacts of these repaired or replaced structures would be analyzed as effects resulting from the project in an ESA consultation. Any impacts on nearshore habitat should be offset, and provides for a range of options from project modifications (soft shore bank armoring, smaller footprints) to incorporation of additional on-site habitat improvements (planting, removal of debris) to obtaining conservation credits.

Repair or replacement of projects extend the life of all or part of that structure for many decades. As a result, the additional life of that structure can cause a net loss of critical habitat quality. Those increments of habitat loss aggregate over time and contribute to the declining trend in habitat quality. Against the backdrop of a continued decline in the quality of nearshore habitat in Puget Sound, repair or replacement projects that cause a net loss of nearshore habitat threaten the survival and recovery of Puget Sound Chinook salmon and Southern Resident killer whales.

Q: How do you measure the impact to know how much conservation offset is necessary? What science and review supports this approach?

In 2016, NMFS began using the Habitat Equivalency Analysis (HEA) methodology in Endangered Species Act consultations in the Puget Sound nearshore environment in the Structures in Marine Waters Programmatic Consultation (WCR-2016-4361, aka “RGP6/SIMP”). Using HEA along with the Puget Sound Nearshore Habitat Values Model (NHVM) (Ehinger et al. 2015), NMFS is able to express impacts through a “calculator” currently in use here:

To measure our impact on the nearshore, NMFS uses:

The Habitat Equivalency Analysis (HEA) methodology

Ecological equivalency that forms the basis of HEA is a concept that uses a common currency to express and assign a value to functional habitat loss and gain. Ecological equivalency is traditionally a service-to-service approach where the ecological functions and services for a species or group of species lost from an impacting activity are fully offset by the services gained from a conservation activity.

HEA, developed by the NOAA Restoration Center, in cooperation with stakeholders, has become a common method for Natural Resource Damage Assessments (NRDA). NMFS chose this methodology for its ESA consultation first, as it adopts and requires a high standard of scientific input and rigor and as well as the fact that this method has withstood multiple legal challenges that can occur during NRDA proceedings.

The Nearshore Habitat Values Model

The NHVM was developed by a team of NMFS biologists in 2015. The model’s values are specific to the designated critical habitat of listed Puget Sound Chinook. These values were derived from scientific literature, and best available information as required by the ESA. This model provides the input parameters for HEA that facilitates the evaluation of impacts and benefits to habitat for listed species. This model was vetted with input from tribes, state and Federal agencies, and consultants as outlined in the acknowledgements.

Since developing the 2015 NHVM, along with continued input from external users, stakeholder, tribes and federal and state scientific peers, NMFS has expanded and updated the model to support a broader suite of nearshore habitat actions. The Batch uses the is expanded and update model.

2015 version of the NHVM along with documentation

A “conservation calculator”

The calculator is a user-friendly interface to simplify HEA and NHVM use and provides a model that numerically characterizes impacts as “debits” and benefits as “credits.”

The calculator allows input of project specific information (e.g., number of piles, bank armoring being replaced, placement relative to forage fish spawning or submerged aquatic vegetation). Using the HEA method that allows for assessment of impacts in time and space, and the habitat values from the NHVM, the calculator produces numerical outputs in the form of conservation credits and debits. Credits (+) indicate positive environmental results to nearshore habitat quality, quantity, or function. Debits (-) on the other hand indicate a loss of nearshore habitat quality, quantity, or function.

Model outputs for new or expanded projects account for impacts to a “pristine” environment and are calculated at a higher debit rate (~2 times greater) than those calculated for replace/repair projects, which assume that some function has already been lost. The calculator outputs account for:

  1. Beneficial aspects of proposed projects, including any positive effects that would result from removing a structure, or piece of a structure, prior to the end of the remaining “useful life period.”
  2. Minimization incorporated through project design improvements (e.g., credit is given for removal replacing creosote piles with steel piles as steel piles typically have less impact on water quality)
  3. Adverse effects that would occur for the duration of a new “useful life period” that would result from the proposed expanded, new, or repaired or replaced structure (or components).

Q: Why would similar projects cause different degrees of impacts?

The number of conservation credits needed for each project is determined by the NHVM conservation calculator. The number of credits needed corresponds to the impact of the project. The Calculator also considers the importance to species of the specific habitat affected by a proposed project. Projects occurring in an important nearshore habitat type will typically incur more debits, and thus need more credits. For instance, development of a pocket estuary will incur more debits due to the importance of these areas to juvenile Puget Sound Chinook salmon. Conversely, the calculator assigns “credits” to many repair or replacement projects for the positive impacts of removing that structure, along with credits for conservation improvements, for a certain period of time. And finally, the model assigns a reduced debit/credit factor to habitat impacted by repaired or replaced projects compared with habitat impacted by new construction to account for the fact that impacts to habitat already impaired by existing structures is less detrimental to species than future impacts to unimpaired habitat.

Q: Does this mean future projects in nearshore habitat will face similar conditions?

Nearshore habitat in Puget Sound continues to decline. This negatively affects the survival and recovery of Puget Sound Chinook salmon and Southern Resident killer whales. We cannot predict the outcome of future consultations in Puget Sound. For instance, an action that had only minor short-term adverse effects combined with long-term beneficial effects on the quality of nearshore habitat may not result in a jeopardy or adverse modification of critical habitat finding. As explained in the preamble to the 2019 revision of the ESA Section 7 regulations, the concept of ‘baseline’ jeopardy does not apply to a section 7 consultation. A jeopardy finding can only be reached if the effects of the proposed action would reasonably be expected, directly or indirectly, to reduce appreciably the likelihood of both the survival and recovery of a listed species in the wild by reducing the reproduction, numbers, or distribution of that species. A poor baseline condition in and of itself cannot cause jeopardy.

If nearshore habitat in Puget Sound quality continues to decline, it seems more likely that projects resulting in a net loss of habitat quality would result in a jeopardy or adverse modification of critical habitat. However, we must evaluate each future proposed action using the appropriate consultation framework and based on the best scientific and commercial data available at that time. We therefore cannot predict the outcome of those future consultations.

Q: Is there a simpler way to determine the number of debits per square footage of an overwater structure in each shore zone?

No, because site specific factors vary from project to project. A structure with no site specific factors (not in natal estuary or embayment/pocket, no forage fish spawning nearby, etc.) may result in a much smaller habitat loss (in DSAYs) than a structure with site specific factors. Additionally, different structures have different impacts. For example, a 100 sq. ft. grated float in the LSZ has a much larger output than a 100 sq. ft. grated pier in the LSZ. Also, new structures are calculated differently because they eliminate new or additional habitat, resulting in a higher impact.

The calculator has mathematical nuances and complexities that attempt to mimic the complexities in the real world. Those "factors" are taken into account when determining habitat gain and loss for our ESA listed salmonids

Q: What kind of conservation measures can offset impacts on nearshore habitat?

There are many options for restoring habitat in ways that offset impacts, whether on the same property or elsewhere. The options may range from elimination of harmful impacts such as toxic creosote pilings or shoreline armoring to restoring wetland habitat that can support juvenile salmon. Adverse impacts are estimated as conservation debits, while improvements are estimated in the form of credits. If project debits exceed credits, project proponents can secure additional credits that offset their net impact, by, for example:

  • Adding on-site habitat improvements to their projects.
  • Removing pilings and overwater structure to reduce impacts on nearshore habitat.
  • Removing shoreline armoring to improve the value of nearshore habitat.
  • Partnering with state agencies, local watershed councils or other local organizations to contribute funds to a project that improves nearshore habitat within the same marine basin or estuary.
  • Partnering with other landowners to remove an in-water and over-water structure within the same marine basin or estuary.
  • Acquiring conservation credits from approved conservation banks and in-lieu fee programs, or a NMFS-approved third-party responsible agreement.

Q: How much would the credits cost?

The cost would be determined by the market as credits are purchased for a comparable amount of habitat improvement or restoration. That value could change over time if more restoration options became available such that the prices change in response to costs and supply and demand. You will need to work directly with a conservation credit provider for cost estimates.

Q: What about advance conservation credits?

Currently, advance conservation credits can only be provided within the framework of conservation banking.

Q: Is it fair to burden someone who wants to build a dock or fix a broken one with saving killer whales?

Recovery of killer whales and the salmon they depend on will take much more than conservation offsets for a specific nearshore project. The required conservation offsets are specific to the impacts of each project, based on what science says about the importance of that habitat to juvenile Chinook salmon, and in turn to Southern Resident killer whales. The conservation responsibility includes only that impact determined based on the design, location, and type of project involved. Some proposed actions might yield a net benefit to the species. That is the case for several projects assessed under this biological opinion: their combined result is a net benefit to juvenile Puget Sound Chinook salmon and therefore they have no conservation offset requirement. For some projects this may increase the cost of the overall project.

Conservation of endangered species and their habitats requires all sectors to do their part. Halting the species decline is a prerequisite for long-term survival and movement towards recovery. In Puget Sound there has been significant conservation progress made in hatchery production, harvest, and fish passage at large dams. The one remaining but most important piece is focused efforts to facilitate progress in habitat protection and restoration. It is imperative to recognize that the expected benefits of habitat restoration will take years or decades to produce significant improvement in natural population viability.

Q: Doesn’t a lot of money already go to habitat restoration?

While the Pacific Coastal Salmon Recovery Fund and other programs do dedicate millions of dollars toward habitat restoration, it is only a sliver of what we calculate will be necessary to recover Puget Sound Chinook salmon and support the Southern Resident killer whales. The Governor's Salmon Recovery Office had reported that in the past 18 years, the Puget Sound regions had received/obtained only 38% of the identified funding needs. By some estimates the funding going to offset the habitat losses we have seen over the decades may be billions of dollars short of what is needed over the longer term to make progress toward recovery.

Q: Why does beach nourishment not fully offset the impacts from a bulkhead?

A bulkhead has several adverse impacts on critical habitat for listed Puget Sound Chinook. First, it renders the area behind the bulkhead inaccessible to juveniles at high tides. This is a big deal, as juvenile salmonids need the shallow water to avoid predators. Second, it prevents sediment supply to the beach. Sediment is important for forage fish at the site and within the entire drift cell. Third, it changes the wave regime and that reduces the ability for wrack and beach logs to accumulate waterward of the armoring. The altered wave regime also contributes to beach lowering and coarsening.

Q: What are on-site actions that could offset the high conservation debits for bulkhead replacements?

The likely most beneficial action around shoreline armoring is reducing the amount of hard armoring. When replacing hard armoring with soft and hybrid approaches, no conservation debits are incurred. For example, installing a pocket beach with soft or hybrid armoring will result in NO impacts for that section of shoreline. In fact, a section of shoreline that replaces hard armoring with soft of hybrid can generate conservation credit[1]. You can use the calculator to find out how large your pocket beach would have to be to offset some hard replacement armoring. Additionally, moving the hard armoring landward will result in reduced impacts.

[1] Credit for the removal of previously unpermitted structures in the nearshore will be approved on a case-by-case basis.

Puget Sound Nearshore Habitat Conservation Calculator main page

Last updated by West Coast Regional Office on June 24, 2022