An Overview of Monitoring Options for Assessing the Response of

An Overview of Monitoring Options for Assessing the Response of
Salmonids and Their Aquatic Ecosystems in the Elwha River Following
Dam Removal
Author(s) :Michael L. McHenry and George R. Pess
Source: Northwest Science, 82(sp1):29-47. 2008.
Published By: Northwest Scientific Association
DOI:
URL: http://www.bioone.org/doi/full/10.3955/0029-344X-82.S.I.29

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Michael L. McHenry1, Lower Elwha Klallam Tribe, Fisheries Department, 51 Hatchery Road, Port Angeles, Washington
98363
and
George R. Pess, NOAA Fisheries, Northwest Fisheries Science Center, 2725 Montlake Boulevard East, Seattle,
Washington 98112

An Overview of Monitoring Options for Assessing the Response of
Salmonids and Their Aquatic Ecosystems in the Elwha River Following
Dam Removal

Abstract
Removal of two hydroelectric dams on the Elwha River, Washington, one of the largest river restoration projects in the United
States, represents a unique opportunity to assess the recovery of fish populations and aquatic ecosystems at the watershed scale.
The current project implementation does not contain sufficient funding to support comprehensive monitoring of restoration effectiveness. As a result, current monitoring efforts are piecemeal and uncoordinated, creating the possibility that project managers
will not be able to answer fundamental questions concerning salmonid and ecosystem response. We present the initial elements
of a monitoring framework designed to assess the effectiveness of dam removal on the recovery of Elwha River salmonids, their
aquatic habitats, and the food webs of which they are an integral component. The monitoring framework is linked to the Elwha
Fisheries Restoration Plan, which outlines the restoration of native stocks of salmon and relies upon a process of adaptive management. The monitoring framework includes two areas of emphasis—salmonid population recovery and ecosystem response. We
provide study design considerations and make recommendations for additional monitoring efforts prior to dam removal. Based
on a power analysis, we determined that a minimum of 3–11 years and up to 50 years of monitoring will be required to capture
potential ecosystem responses following dam removal. The development of a monitoring plan will be a significant step forward
in objectively evaluating the success of Elwha River dam removal.

Introduction
In the United States the number of aging dams nearing their life expectancies is projected to increase
dramatically in the next several decades (Heinz
Center 2002, Poff and Hart 2002, Stanley and
Doyle 2003). Dams that are no longer economically
viable or dams that have negative environmental
effects will be candidates for potential removal.
Over the last two decades approximately 500 dams
have been removed in the United States (Pohl
2002). Most of these have been small dams (<2 m
height) and only a few have been systematically
evaluated for ecological responses (Stanley and
Doyle 2003).
The Elwha River Ecosystem and Fisheries
Restoration Act of 1994 calls for full restoration
of native anadromous fish populations and their
ecosystem, with dam removal having been determined to be the most effective means to achieve
this goal (DOI et al. 1994, DOI 1996a). This
legislation will ultimately result in the removal of
1

Author to whom correspondence should be addressed:
Email [email protected]

the Elwha (32 m high) and Glines Canyon Dams
(64 m high) between 2012 and 2014 (Duda et al.
2008). Dam removal presents a unique opportunity
to assess salmon recolonization and ecosystem
recovery processes. Extant populations of salmon
persist in the Elwha River below the dams, providing a source of colonizers. Additionally, the
majority of the Elwha River drainage is located in
Olympic National Park (ONP) and is considered
nearly pristine. As a result, Elwha dam removal
represents a true watershed scale restoration effort
(Wohl et al. 2005).
The specific mechanisms for achieving restoration of native anadromous fish populations have
only recently been defined in the Elwha Fisheries
Recovery Plan (Ward et al. in press, hereafter
refered to as Recovery Plan). Efforts to recover
naturally-reproducing anadromous salmon within
the Elwha River basin will be achieved through
the preservation of extant stocks of anadromous
fish during the removal of the Elwha dams, and
through rehabilitation of all anadromous fish
populations following dam removal. The goals of
the Recovery Plan (Ward et al. in press) are:

Northwest
Science,
82,Removal
Special Monitoring
Issue, 2008
Elwha
RiverVol.
Dam

29

1. Re-establish self-sustaining anadromous
salmonid populations in habitats of the Elwha
River within 5 to 10 generations (i.e., 20 to
40 yrs);
2. Maintain the integrity of the existing native
salmonid gene pools during the dam removal
period;
3. Monitor pathogen distribution in fish populations before and after dam removal; and
4. Evaluate the physical and biological response
of the overall ecosystem to dam removal and
the return of salmon populations.
Funding for dam purchase, dam removal, and
water supply protection was included as part of the
Act; however, due to numerous issues (Winter and
Crain 2008) funding for monitoring the ecosystem
response to the removal of the Elwha River dams
was not included in the Act. This has resulted in
an amalgamation of individual studies that are
focused upon specific questions related to dam
removal and ecosystem response, some of which
are published in this special issue of Northwest
Science. Although a centralized monitoring plan
based upon the Elwha Restoration Act has not

occurred to date, there are basic questions related
to objectives in the Act and the Recovery Plan
that need to be addressed but will not be met by
ongoing and proposed scientific studies. Because
there are numerous uncertainties concerning the
response of salmonids to dam removal on the Elwha
(Table 1), project managers are heavily reliant on
the concept of adaptive management (Lee 1993) to
answer questions concerning project effectiveness.
One of the central requirements of an adaptive
management approach is the adjustment of project
implementation, based upon data collection, so
that restoration goals will be achieved.
Our intention is to focus directly on the response
of fish and ecosystem components (goals 1 and
4, above) to dam removal in the Elwha River. We
base this upon the recommendations outlined by
Roni et al. (2005) for monitoring and evaluating
the response of salmonids and their aquatic ecosystems to dam removal and ecosystem restoration. We define specific parameters that are or
will be measured to a basic conceptual framework
that captures some of the major hypotheses and
predictions addressed in detail by other papers in
this issue (e.g., Brenkman et al. 2008a, Kloehn

TABLE 1. Assumptions used in the development of the Elwha River Fish Restoration Plan (Ward et al. in press).
Fish Restoration Plan Assumption

Uncertainty

Sediment levels return to background levels in 2-5 yrs
after dams are removed

· Assumptions and simplifications of hydrological and
sediment transport models
· Stabilization of reservoir sediments via revegetation
efforts minimizes erosion

All native populations of salmonids survive dam
removal disturbance

· 3 populations are ESA listed (threatened) and others
currently have low population sizes

Recovery rates of salmon populations are steady state
and immediate following dam removal

· Dam removal may initially cause salmon populations to
decline in the short term
· Recolonization into some areas may take longer than
anticipated
· Unanticipated barriers to migration may emerge
· Recolonization rates may change

“Fish Windows”—where deconstruction is temporarily
halted at specific times of the year—will minimize
negative effects of high sediment loads to exant
populations below the dams and will facilitate
collection of brood stock

· Turbidity may remain high for prolonged periods during “Fish
Windows” reducing ability to collect broodstock. Alternatively,
salmon may avoid river outright during times of high turbidity

Hatchery supplementation will speed recovery of stocks

· Whether hatchery supplementation will allow faster recovery
than natural recolonization

Monitoring will allow meaningful evaluation of
management actions

· Funding levels are commensurate with requirements for
data collection

30

McHenry and Pess

TABLE 2. Existing status of sediment supply and migration barriers in the Elwha and Quinault Rivers. The Elwha River is divided
into sections by two dams.$ = change.

Reach
Lower Elwha
Middle Elwha
Upper Elwha
Quinault
1
2

________Sediment Supply________
Current
Post dam
conditions
removal $
Unnatural
Unnatural
Natural
Natural

Yes
Yes
No
No

________Barriers to Migration________
Current
Post dam removal
conditions
fish community $
Yes1
Yes1
Yes2
No

No
Yes
Yes
No

dams block migration
natural seasonal velocity barriers

et al. 2008, Morley et al. 2008, Pess et al. 2008,
Winans et al. 2008, Woodward et al. 2008). Spatial and temporal scale issues are discussed as
part of the study design associated with each of
the parameters. How individual parameters will
be measured is described in general terms, and
specific references are given for existing and proposed methods. For a sub-set of these monitoring
parameters we present a statistical power analysis
that estimates the number of years that will be
required to detect ecosystem response to dam
removal. Finally, for each parameter we describe
the types of metrics and data analyses that will
be used to analyze trends and patterns in relation
to the conceptual framework and hypotheses put
forth in other papers in this issue.

Construction of dams on the Elwha River
has dramatically reduced habitat availability
and quality resulting in isolated populations of
resident and anadromous fish. These populations
have declined dramatically over historic levels
(Pess et al. 2008). The severity of effects to the
Elwha ecosystem varies by reach. The reaches
below Elwha Dam (lower Elwha) and between
Elwha and Glines Canyon Dams (middle Elwha)
have undergone similar physical but different
biological impacts, while the upper Elwha has
undergone similar biological impacts but has not
been physically impacted (Table 2). These reaches
represent logical spatial boundaries for describing
the conceptual framework to ecosystem response
following dam removal.

A Framework for Creating General
Monitoring Questions Based Upon
Recovery Objectives

The Lower Elwha (Estuary to Elwha Dam)

Our first consideration in developing a monitoring framework for the Elwha River dam removals
was to clearly define working hypotheses based
upon Recovery Plan goals (1 and 4) for salmonid
populations and associated habitat. The effects of
Elwha dam removals on salmonid recolonization,
population sustainability, and ecosystem response
can be addressed by two main questions: (1) What
effect(s) will dam removal have on the quantity,
quality and spatial extent of habitat over time?
and; (2) What effect(s) will dam removal have on
the abundance and distribution of salmonids over
time? The development of working hypotheses for
Elwha River dam removal is logically framed by
existing spatial boundaries defined by the dams
and the impacts from dam construction and removal (see discussion in Duda et al. 2008). These
working hypotheses will predict the trajectory of
ecosystem response following dam removal.

The lower Elwha River (rkm 0-8) has arguably
been most impacted by the dams and will be most
impacted by dam removal. Dam construction
dramatically reduced the capacity of the river to
transport sediment and wood from upriver sources,
a necessary process for creation and maintenance
of in-river habitat. The lower Elwha has also been
impacted by flow manipulations, thermal alterations, and floodplain degradation from diking,
logging, and channelization. This has significantly
reduced the abundance of native salmonids. However, anadromous salmonids persist as fragmented
populations (Brenkman et al. 2008a, Pess et al.
2008) that have retained a high degree of genetic
diversity (Winans et al. 2008).
Dam removal will result in changes to aquatic
habitat quality and channel morphology in mainstem and floodplain habitats in the lower Elwha
due to increased rates of fine and coarse sediment
transport. Increases in sediment transport will
result in increased turbidity levels, stream channel
Elwha River Dam Removal Monitoring

31

aggradation, and stream channel instability (Pess
et al. 2008, DOI 1996b). Sediment transport modeling (USACOE 1999) suggests that aggradation
of channel beds downstream of the dams will be
relatively minor during the first 3–5 yr following
dam removal. The initial wave of fine sediments
is expected to increase turbidity and temporarily
fill pools, but not significantly raise channel bed
elevations (DOI 1996b). Coarse sediments stored
within the dams are predicted to reach the lower
Elwha after several decades, and are modeled to
increase bed aggradation by about one meter, in
some areas, after 50 yr (DOI 1996b). The rates
and duration of turbidity generated by stored
fine sediments in the reservoirs are relevant to
extant downstream biological populations, and
will likely affect salmonid growth and survival
in the lower Elwha.
A confounding aspect of the conceptual framework with respect to salmonid response is the use
of hatchery outplants. Two hatcheries (Washington Department of Fish and Wildlife Spawning
Channel [WDFW] and the Lower Elwha Klallam Tribal [LEKT] Hatchery) were constructed
in the lower Elwha River during the 1970s to
offset losses in natural salmon production. Following dam removal these facilities will be used
to provide coho salmon (Oncorhynchus kisutch)
and Chinook salmon (O. tshawytscha) smolts
derived from native Elwha stocks in an effort to
maximize returns of adults (Ward et al. in press).
The hatcheries will also be used to maintain and
rebuild remnant populations of pink salmon (O.
gorbusha), chum salmon (O. keta), and steelhead
(O. mykiss) through the dam removal period using broodstock conservation programs. Because
of their current reduced population sizes, only
small numbers of these species will be moved to
selected habitats (as eyed eggs in hatchboxes, fed
fry, or smolts), during and immediately following
dam removal (Ward et al. in press). The primary
focus of hatchery efforts for these species will be
to maintain extant populations through a period of
short term negative impacts (largely sedimentation) expected following dam removal.
The Middle Elwha (Elwha Dam to Rica
Canyon).
The middle Elwha (rkm 8–26) has also been impacted by a dramatic reduction of sediment and
wood from upstream sources as a result of the
construction Glines Canyon Dam in 1927. The
32

McHenry and Pess

dams have also submerged ~10 km (40%) of the
reach in two reservoirs, resulting in broadscale
shifts from lentic to lotic processes. Changes to the
native salmonid assemblage in the middle Elwha
have been profound due to the direct loss anadromous salmonids. The remnant fish community
is now greatly simplified, consisting of rainbow
trout, bull trout (Salvelinus confluentus), sculpin
(Cottus spp.), and an established population of
exotic brook trout (S. fontinalis) (Brenkman et
al. 2008a). The complete loss of marine derived
nutrients (MDN) from returning anadromous
salmonids has likely altered food webs within the
middle Elwha (Munn et al. 1996, 1998; Morley
et al. 2008).
Effects of dam removal on the middle Elwha
will be similar to the lower Elwha in terms of
fine sediment (DOI 1996b). In contrast, stream
channel aggradation will be significantly less
in the middle Elwha than in the lower Elwha,
primarily because sediment transport capacity is
higher in the steeper middle reach (DOI 1996b,
Pohl 2004, Kloehn et al. 2008). As a result, the
primary impacts in this reach are likely to be short
term and associated with turbidity spikes during
and immediately following dam removal.
The middle Elwha will be used to test the effectiveness of hatchery supplementation over a
single generation (2–5 yrs, depending on species).
A single generation for each species was chosen
as a point to assess the initial effectiveness of
hatchery supplementation efforts. Although all
native species are anticipated to use this reach
(DOI et al. 1994), only Chinook salmon and coho
salmon will be planted from the hatcheries in significant numbers (Ward et al. in press). The middle
Elwha contains forested floodplain habitats with
numerous side channels and is hypothesized to be
quickly colonized by both natural and hatchery
origin fish following the removal of Elwha Dam
(DOI et al. 1994, Pess et al. 2008).
The middle Elwha also contains two large
tributaries, Indian Creek and Little River, that are
accessible to salmonids and will not be affected
by increases in sedimentation from dam removal.
These tributaries provide opportunities for recolonization experiments testing the efficacy of
natural and hatchery outplanting techniques. The
Little River supports a mixed origin population
of resident rainbow trout, including an isolated
headwater population possibly of native origin

(Phelps et al. 2001, but see Winans et al. 2008).
Resident rainbow trout populations isolated from
anadromous populations are capable of producing
anadromous smolts many generations removed from
their isolation above anadromous barriers (Hiss
and Wunderlich 1994a, Thrower and Joyce 2004).
Thus, the Little River is ideal to assess natural recolonization mechanisms by steelhead, particularly
given that no hatchery outplanting is planned for
the Little River (Ward et al. in press).
Indian Creek drains Lake Sutherland which
historically supported a population of sockeye
salmon (O. nerka). A robust population of natural reproducing kokanee (the resident form of
O. nerka) in the lake may be producing small
numbers of anadromous smolts (Hiss and Wunderlich 1994b). Dam removal will allow access by
naturally colonizing anadromous sockeye salmon
without hatchery supplementation (Ward et al. in
press). In contrast, other salmon species, particularly coho, derived from hatchery outplants will
be directly seeded into Indian Creek (Ward et al.
in press). The higher proportion of low gradient
channels, associated wetlands and the presence of
Lake Sutherland also make the Indian Creek basin
highly suitable for coho salmon recolonization
(Pess et al. 2008). Thus, Indian Creek is ideal to
assess coho salmon recolonization mechanisms
comparing natural and hatchery supplementation
methods (Ward et al. in press).
The Upper Elwha (Rica Canyon to
Headwaters)
The upper Elwha (> rkm 26) will not dramatically change in terms of physical watershed
inputs because of dam removal. Natural sediment
supply from the upper Elwha River basin since
1927 (when Glines Canyon Dam was built) has
averaged 146 m3 km-2 yr-1 (DOI 1996b). However,
similar to the middle Elwha, the salmonid fish
assemblage has been greatly simplified by dam
construction (Brenkman et al. 2008a). The upper
Elwha River provides a potential reference reach to
assess recolonization for the majority of salmonid
species. We define a salmonid reference area as
a section (100s of meters to kilometers) of the
river where no hatchery practices are conducted
for the purpose of accelerating recolonization for
a particular species. However, the upper Elwha
will not be a reference for all salmonid species
because the Recovery Plan currently targets limited
Chinook outplanting from hatchery sources in

the upper watershed during the first 10 yr (Ward
et al. in press). Natural recolonization will be
the primary mechanism for other species such
as coho salmon, steelhead, cutthroat trout (O.
clarki), and bull trout. Pink salmon and chum
salmon may colonize only limited portions of the
upper Elwha, as stream gradient and confinement
increases dramatically above ~rkm 30 (the Grand
Canyon of the Elwha) and may ultimately limit
their distribution (DOI et al. 1994, Brenkman et
al. 2008a, Pess et al. 2008).
As none of the tributaries in the upper Elwha
will have directed outplanting, they will also be
considered reference areas for natural recolonization. Major tributaries in the upper Elwha
include Hayes, Lillian, Lost, Goldie rivers and
Long creek (Figure 1, see also Table 1, Brenkman
et al. 2008a). Existing anadromous and resident
populations below each dam will have the opportunity to colonize if they can successfully survive
deleterious sediment impacts, by utilizing existing refuge habitats such as groundwater fed side
channels and tributaries. We hypothesize that in
general salmonids will respond to dam removal by
establishing persistent, self-sustaining salmonid
populations in the middle and upper Elwha within
in one to five generations (2–30 yr) following dam
removal (Pess et al. 2008).
In summary, the conceptual framework for dam
removal in the Elwha River will be based upon the
relative spatial location of the river reach (lower,
middle and upper Elwha) as affected by past impacts (dam construction, reservoir innundation) and
potential response (physical and biological inputs)
to dam removal. Planned management practices,
particularly the use of hatcheries to accelerate
fish recolonization rates, present challenges to
the development of a conceptual framework for
monitoring, particularly with regards to establishing reference reaches. However, it is important to
note that hatchery outplanting is limited and will
be curtailed following recovery.
Monitoring Design Considerations
Many study designs have been proposed for use
in evaluation of watershed restoration including
before-after (BA), before-after control-impact
(BACI), post treatment, and various modifications
of these designs such as beyond BACI (Hicks et
al. 1991, Underwood 1994, Roni et al. 2005;).
Any design calling for a true “control” will be
Elwha River Dam Removal Monitoring

33

Figure 1. The Elwha River watershed. Reach boundaries are defined as lower Elwha (Estuary
to Elwha Dam), middle Elwha (Elwha Dam to Rica Canyon), and upper Elwha (Rica
Canyon to Headwaters).

difficult in the case of the Elwha River dam removals, because no true control watershed exists for
the Elwha and no comparable dams exist in the
same region of the Olympic Peninsula. Given the
current availability of resources, we believe that
the most appropriate study design for the Elwha
River dam removal is a BA design.
Although no true control watersheds exist,
we have attempted to identify potential reference
watersheds or river reaches throughout western
34

McHenry and Pess

Washington based on geologic, hydrologic, and
ecological variables. The goal of such reference
sites is to account for variability in response variables due to factors that operate at larger scales,
such as regional weather patterns or long-term climate change, which would operate independently
from effects associated with dam removal. Such
reference reaches could allow for the identification of larger trends in data gathered before and
after dam removal.

Figure 2. An example reference river selection, based upon river discharge and slope, which compares
the Elwha River with other Olympic Peninsula and Puget Sound watersheds.

We examined several locations across western
Washington. Based on watershed area and flow
characteristics, we found the upper Quinault
River to be similar to the lower Elwha (Figure 2).
Additionally, both the Quinault and Elwha rivers
have similar geology, geomorphic and channel
characteristics (e.g., large, low-gradient meandering channels with forested floodplains), and a distribution of hydrologic regimes in each watershed
(snow-dominated, transition, and rain-dominated).
The Quinault River has been used as a reference
reach in existing studies of invertebrates (Morley
et al. 2008), river-floodplain dynamics (Kloehn
et al. 2008) and fish use that will help inform the
outcome of patterns in the Elwha River. It will
also serve as a reference to account for large-scale
environmental variability (e.g., ocean and climate
conditions) that will also affect the Elwha River
during and after dam removal. In addition, alluvial
reaches in the upper Elwha River will provide
reference reaches for reach-level comparisons
of habitat quality in the middle and lower Elwha.
These unimpacted alluvial reaches also provide a
template for how downstream reaches functioned
before dam construction.

A single reference reach may limit the ability
to infer whether post-dam removal changes are
due to the restoration or other factors operating
at regional or global scales. However, additional
reference sites can also contain high levels of
natural variability between sites, as is the case
when we examined other potential sites in western
Washington. Thus, adding additional unsuitable
reference sites could make it difficult to identify
the signal of the impact (e.g., sediment) or treatment (e.g., reopening of habitat) variables. The
Quinault River is a comparable site which will
allow us an opportunity to identify changes due
to dam removal, but in all likelihood will not
allow for quantitative results to be extrapolated
beyond the Elwha.
Monitoring Objectives
Re-establish Self-sustaining Anadromous
Salmonid Populations
The primary monitoring objective related to the
goal of re-establishing self-sustaining anadromous
salmonid populations is to quantify the recolonization rate of habitats by different salmonid
Elwha River Dam Removal Monitoring

35

species over time. We use two criteria to define a
self-sustaining population: 1) colonizing population growth rate exceeds emigration (stray rates
from the colonizing population) and immigration (stray rates from the source population);
and 2) over 50% of returning adult spawners are
from parents that originated from the same area
(Cooper and Mangel 1998). Rates of population growth and development of self-sustaining
salmonid populations above the dams will vary
by species-specific tendencies to reoccupy newly
opened habitats, distance from source populations,
current population size, and the influence of other
management practices identified in the Recovery
Plan (Pess et al. 2008). For example, the introduction of hatchery fish at different life stages and
in different locations throughout the Elwha River
basin will contribute to species-specific spatial and
temporal variability in recolonization rates. Recolonization will occur by two processes—natural
recolonization and hatchery supplementation. We
define natural recolonization as the establishment
of self-sustaining populations without the aid of
directed hatchery management techniques such as
the planting of fish at specific life stages (e.g., fry
or smolt). A complete discussion of how natural
recolonization rates vary and how this could effect recolonization in the Elwha is provided by
Pess et al. (2008).
The Recovery Plan states that natural recolonization will be allowed to occur for species or
life forms that are not currently maintained by
hatchery production (Ward et al. in press). This
includes summer run Chinook salmon, cutthroat
trout, bull trout, and sockeye salmon. Hatchery
supplementation will be used for other species
such as coho salmon and Chinook salmon, which
have a long history of being raised and planted
into the lower Elwha in high numbers. Populations of some species such as pink salmon, chum
salmon, and winter run steelhead are currently
at such low numbers (<1000, <150, and <250
returning adults, respectively) that hatcheries
will be used to maintain populations during dam
removal through broodstock maintenance programs
that attempt to promote gene conservation. The
number of hatchery salmonids planted into the
Elwha River at different life stages (outplanting)
in subsequent generations will be primarily based
upon population rebuilding rates and to a lesser
extent the availability of salmonid stocks in the
lower Elwha (Ward et al. in press).
36

McHenry and Pess

The combination of natural and artificial recolonization for some salmonid species confounds
attempts at quantifying salmonid recolonization in
the Elwha River. Various supplementation strategies will be used at different locations within the
three general reaches (lower, middle, and upper
Elwha). Each reach will receive different levels
of supplementation: (1) single species (Chinook
salmon) supplementation in the upper Elwha;
(2) a temporally (e.g., 5 yr) and spatially limited
multiple-species supplementation in the middle
Elwha; and (3) a standard practice supplementation
reach below Elwha Dam (Ward et al. in press).
It is understood that there is a great deal of
spatial and temporal interdependence between
locations in a river network due to fluvial connectivity and the ability of fish to move upstream.
For example, upstream inefficiencies in nutrients
and primary productivity can create opportunities
and benefits to downstream recipient organisms
(Vannote et al. 1980, Polis et al. 1997). Salmonids
can migrate from disturbed areas and establish
spawning populations following a major disturbance, resulting in population densities that were
greater than prior to the disturbance (Roghair and
Dolloff 2005). Thus, there will be interdependence
and correlation between upstream inputs and
downstream productivity in the same system or
movement of the response variable of interest
between control and impact reaches. The goal of
having different strategies in different locations
is to focus hatchery supplementation efforts into
discrete areas, which may provide an opportunity
to examine natural recolonization of those species with no hatchery supplementation at a preidentified scale (e.g., site, reach, and watershed)
and potential areas to observe interactions between
natural and hatchery produced salmonids within
a given species.
One way to quantify the interactions of hatchery
supplementation between these different strategies
is to mark all hatchery fish released so that the
origin of adults can be determined. This will also
allow for the assessment of the effectiveness of
hatchery supplementation toward the establishment of self-sustaining spawning populations.
Initial efforts have been made to differentiate
between hatchery and naturally spawning salmonids in the Elwha River. Chinook salmon from
the WDFW hatchery are now thermally marked
as juveniles, allowing the determination of origin through otolith analysis. Coho salmon and

steelhead from the LEKT hatchery are currently
marked with either coded wire tags (CWT) or fin
clips. An additional tool is the analysis of tissue
samples, collected from adult or juvenile fish,
using microsatellite DNA markers. Winans et al.
(2008) are currently establishing genetic baselines
for all Elwha salmonids (natural and hatchery).
This information can be used to assess parentage
and thus the origin of fish occupying any given
habitat in the Elwha.
Recolonization Monitoring Parameters
The measurement of several parameters to enumerate fish recolonization rates, including adult and
juvenile abundance, recruits per spawner, smolts
per spawner, proportion of native origin returns,
and survival at specific life stages (Table 3) will
be necessary to adequately monitor salmonid
recolonization response. In addition, the proportion of potentially habitable river network that is
occupied by anadromous salmonids will be an
important measure of changes in spatial distribution due to dam removal (Table 3). Large-scale
disturbances that have both immediate (e.g., pulse)
and long-term (e.g., press) effects can translate
to changes in variation (Underwood 1994). The
Elwha dam removals are an excellent example. If
salmonid species survive the short-term, negative

disturbance associated with increased levels of
sediment and temporally unstable habitats, then
large areas of newly accessible habitat may result
in long-term gains at the population level. We will
use adult and juvenile abundance and population
productivity metrics to assess both short- and
long-term changes at the population level (Table
3). These metrics will include the rate of change,
mean, and variance in each parameter category.
We will attempt to measure the rate of change of
these parameters in occupied and newly accessible
habitats to gain a watershed-scale perspective of
the relative contribution of new habitats.
The general sampling approach for recolonization parameters will be a stratified sampling approach (Table 3). A stratified sampling approach
uses the hierarchical nature of physical and biotic
variables to identify how each variable is nested
within a larger variables, and at which scale this
occurs. For example, stream channel substrate is
nested within several variables occurring at larger
scales, including channel gradient, valley confinement, channel roughness and geology. Spatially
this also incorporates the heterogeneous nature,
or patchiness, of the habitat being sampled. Many
of these differences are captured in the Elwha
River by general habitat types such as tributary,
confined mainstem, unconfined mainstem, and

TABLE 3. Fish recolonization parameters expected to be monitored before, during, and after dam removal in the Elwha River.
Reach scale refers to newly opened and pre-dam removal reaches
Parameter

Scale

Statistics

Technique(s)

Frequency

Sampling Scheme

Adult-Abundance1

Reach and population

Mean
Variance
Rate of change

Spawner surveys

Annual

Stratified by habitat
and using index
reaches and random
sampling

Juvenile Abundance2 Reach and population

Mean
Variance
Rate of change

Snorkeling
Electrofishing

Seasonal
and annual

Same as above

Productivity

Recruits per
spawner
Smolts per
spawner

Spawner surveys

Annual

Same as above

Smolt traps

Annual

Reach and population

Origin

Reach and population

% return

Microsatellite
DNA markers

Annual

Same as above

Distribution

Reach

Proportion of
newly opened
habitat occupied

Spawner surveys
Radio-telemetry

Annual
Supplimental
to surveys

Same as above

1
2

Chinook salmon, pink salmon, steelhead
Chinook salmon, coho, steelhead.

Elwha River Dam Removal Monitoring

37

TABLE 4. Adult salmon population enumeration techniques based upon species and location. Spawner surveys are not feasible
for all species and reaches due to seasonal differences in flow and visibility associated with peak spawning time of
different species (Adapted from Roni et al. 2005). NA = not applicable.
Location

Chinook

Coho

Steelhead

Pink

Chum

Sockeye

Tributaries

NA

Spawner survey

Spawner survey

Spawner survey

Spawner survey

Weir counts

Side Channels

Spawner survey

Spawner survey

Spawner survey

Spawner survey

Spawner survey

NA

Upper ElwhaMainstem

Spawner survey

Spawner survey

Spawner survey

Spawner survey

Spawner survey

NA

Middle ElwhaMainstem

Spawner survey

Spawner survey
Fish Wheel
Sonar

Spawner survey

Spawner survey

Spawner survey
Fish Wheel
Sonar

Weir counts

Lower ElwhaMainstem

Spawner survey

Sonar

Spawner survey

Spawner survey

Sonar

Weir counts

floodplain (Munn et al. 1998, Kloehn et al. 2008,
Pess et al. 2008) measured over time at specified
locations. We will attempt to include replication
at specific scales such as the site or reach and to
include random sampling in the overall structure
of the sampling approach so as not to just focus on
index reaches over time. However, due to funding
constraints it is unclear how much replication and
random sampling will occur and whether or not
there will be balanced number of sites for each
parameter category.
We will measure adult salmonid abundance by
the number of returning adults. Spawner surveys
will be used to determine the number of returning adults during summer, early fall, and spring
when flows are typically low and clear. During
these time periods, we will focus upon Chinook
salmon, pink salmon, and steelhead. Spawning
ground surveys of live fish, carcasses, and redds
will be conducted on foot at 10–14 day intervals
throughout the spawning period. Spawner surveys
will include mainstem, floodplain, and tributary
channels to gain comprehensive estimates of adult
salmonid abundance and distribution by major
habitat type. This technique has been established
in the lower Elwha, but will need to be expanded
into the middle and upper Elwha following dam
removal. The upper Elwha presents a significant
challenge, as access to roadless areas at the limit
of upriver fish distribution requires multi-day (at
least 5 days for the uppermost portions of the
watershed) hiking in the backcountry.
Fall and winter spawning species (coho salmon
and chum salmon) that return when river discharge
38

McHenry and Pess

is typically higher (and visibility lower) make
traditional visual survey techniques difficult,
particularly in mainstem habitats. Other sampling
technologies, including a fish wheel (Meeham
1961) and sonar imaging (Moursund et al. 2003),
are currently being tested on the Elwha River to
ascertain their ability to estimate adult abundance.
If successful, a fish wheel can be used to estimate adult population size using mark-recapture
techniques. It is important to note that accurate
measures of adult abundance will be challenging
to obtain in the Elwha because of access, flow, and
visibility issues. Table 4 summarizes the existing
and projected adult enumeration techniques by
species and habitat type for the Elwha River.
Radio-telemetry (High et al. 2006) will be applied to assist the determination of recolonization
rates to the upper basin. This technique may be particularly useful for fall and winter timed spawners
that will be difficult to enumerate using traditional
counts. A series of seven monitoring antennas have
been established along an upstream gradient in
the Elwha River. This system is currently being
used to assess bull trout and resident rainbow
trout movements in the river sections above,
between, and below the dams (Sam Brenkman,
Olympic National Park, personal communication)
as well as coho salmon (Burke et al. 2008) and
winter-run steelhead behavior in the lower Elwha.
Individual adult fish will be captured in the lower
river and surgically implanted with radio tags to
assess upstream migration rates and distances.
Supplemental ground tracking and aerial overflights will be conducted in an effort to expand

spatial coverage of the watershed with the goal
of identifying spawning aggregations.
Repeatable spatial and temporal monitoring of
juvenile abundance using snorkeling techniques
at stratified (e.g., mainstem, floodplain, and,
tributary habitats within the lower, middle, and
upper Elwha) index areas as well as in randomly
sampled locations will be an important technique
for monitoring response of Elwha fish communities. Snorkeling provides non-invasive, reasonably
precise estimation of abundance (Thurow et al.
2006). Juvenile fish population estimates conducted
over different reaches of the river can be used not
only to monitor recolonization of habitats, but
changes in fish community structure over time.
This will be particularly important in the middle
and upper Elwha, where fish communities are
currently dominated by resident rainbow trout and
bull trout (Brenkman et al. 2008a). As anadromous
species move into these areas, community structure
is anticipated to change, as seen in other Pacific
Northwest watersheds where recolonization has
occurred (Brenkman et al. 2008a, Anderson et
al. in press).
Snorkel surveys are considered an appropriate
tool to use in the Elwha because the natural variability between units, seasons, and years can be
quite high (Pess et al. 2008). Having high natural
variability means that sampling greater habitat
area increases the precision of mean density
estimates relative to the trade-off of increasing
observation error, which can typically be larger
with snorkel surveys relative to other techniques
such as electrofishing. Regardless of the technique
utilized both observation and process error will
be quantified in order to detect trends following
dam removal. The biggest drawback with using
snorkel surveys will occur during and immediately
after dam removal when turbidity levels are high
and visibility will be low. During these periods,
other methods such as electroshocking (Connolly and Brenkman 2008) and seining will be
utilized to obtain juvenile population estimates
in mainstem habitats.
To assess changes in salmonid productivity, we
will monitor smolt abundance using traps including rotary screw traps in the mainstem and fence
weirs in floodplain channels and tributaries. Currently a 2.45 m diameter rotary screw trap is used
in the lower Elwha (rkm 0.5) between February
and June to sample smolt outmigration rates and

timing. The screw trap has been fished annually
since 2005, sampling a small proportion of the
flow during peak outmigration periods. This has
allowed for the estimation of smolt production
for several salmon species including Chinook,
coho, pink, and chum. The trap will be used in
combination with adult enumeration to provide
estimates of productivity such as the number of
smolts produced per spawner. Additional smolt trap
sites will be established following dam removal to
monitor production from newly accessible portions
of the watershed. Of particular importance will be
an additional mainstem site that would measure
output from the upper Elwha watershed and in
the large middle Elwha tributaries (Indian Creek
and Little River). Smolt traps will also provide
a convenient means of collecting fish for genetic
analysis, fish health screening, and tagging.
Evaluating Physical and Biological
Ecosystem Responses
Dam removal on the Elwha River will release
large volumes of stored sediment that will, over
the short term, affect ecosystem productivity in
the downstream reaches, estuary and nearshore. As
sediment levels stabilize following dam removal,
populations of anadromous fish will colonize
upstream reaches increasing nutrient availability
for freshwater ecosystems after nine decades
of absence. Dam removal also restores natural
hydrologic conditions (flow, temperature) and
other critical habitat forming processes (large
wood transport). Additionally, two reservoirs will
be drained and exposed sediments on the reservoir bottom will be revegetated through natural
processes (Brown and Chenoweth 2008) as well
as supplemental revegetation (Chenoweth et al.
in press). Sedimentation due to dam removal and
subsequent habitat degradation, the restoration of
natural watershed processes, habitat expansion, and
increases in nutrient availability focus the Elwha
River ecosystem recovery monitoring efforts on
four areas: (1) habitat and food web response to
the release of stored sediment in the middle and
lower Elwha; (2) food web response to salmon
recolonization in the middle and upper Elwha;
(3) the recovery of reservoir reaches as forests
recolonize exposed reservoir sediments; and (4)
responses of the river delta and nearshore ecosystem to release of stored sediment. We emphasize
one and three and note that Elwha food web
response (Morley et al. 2008) and the nearshore
Elwha River Dam Removal Monitoring

39

monitoring efforts are developing simultaneously
(e.g., Schwartz 2005, Warrick et al 2008; see also
Shaffer et al. 2008).
Habitat Response to the Release of Stored
Sediment
Measuring the response of fish habitat to the release of stored sediment will focus on the mean,
variance, and rate of change in habitat quantity
and quality (Table 5). We will monitor spawning
gravel beds in mainstem and side-channel habitats in the lower and middle reaches (including
the reservoirs), where the greatest changes are
anticipated as a result of dam removal. In addition there will be reference sites in the lower
portion of the upper Elwha (e.g., Geyser Valley),
and the Quinault reference reach in order to gain
a quantitative estimate of variability in available
spawning area for each habitat type. Spawning
gravel aggregations are defined as gravels (16–64
mm) and cobbles (64–128 mm) that exceed 3.0
m2 in surface area for larger salmonids, and 1.5m2
for smaller salmonids (Bjornn and Reiser 1991,
Beechie and Sibley 1997). These areas will be
located and mapped using GIS. This technique
has been used to map changes in Chinook spawning aggregations in the lower Elwha (McHenry
et al. 2007).

We will monitor changes to the bed surface and
subsurface in order to quantify changes in spawning
habitat quality over time (Table 5). Large increases
in the supply of fine sediment will affect quality
of salmon spawning habitats and may be visually
obvious in the bed surface material (Roni et al. in
press). These can be evaluated by surface pebble
counts or a measure of embeddedness (e.g., Potyondy 1989). More subtle changes in fine sediment
delivery to channels can be monitored by changes in
the subsurface material, which may not be obvious
on the bed surface (Young et al. 1991).
We propose to visually estimate substrate size
and embeddedness in every potential spawning
area, and to conduct pebble counts (Wolman
1954) in every 10th habitat measured (Roni et
al. in press). We will analyze changes in D50 and
the proportion of substrate that is sand or finer
(< 2 mm) over time. Annual summer surveys are
initially recommended for all spawning habitat
quality and quantity metrics, though periodic
(every other year or third year) may be more
feasible. We also propose to monitor subsurface
fine sediment (< 0.85 mm) using bulk sampling
techniques (Schuett-Hames et al. 1999) in selected areas of the Elwha River. Emphasis will
be placed on habitats in the lower and middle
reaches (including exposed reservoir surfaces
following dam removal). Areas in the upper

TABLE 5. Candidate ecosystem monitoring parameters that could be collected before, during, and after dam removal in the
Elwha River. Reach scale includes newly opened and pre-dam removal reaches.
Parameter

Scale

Statistics

Technique

Frequency

Sampling Scheme

Habitat response
to release of stored
reservoir sediment

Reach/watershed

Mean
Variance
Rate of change

Gravel mapping

Annual

Stratified and including
index reaches and annual
randomly located sites

Reach/watershed

Mean
Variance
Rate of change

Embeddedness

Annual before
and every 3 yrs
following dam
removal

Every 10th habitat sampled

Reach/watershed

Mean
Variance
Rate of change

Sub-surface
Same as above
sediment sampling

Stratified and including
index reaches and
randomly located sites

Reach/watershed

Mean
Variance
Rate of change

Census of pool
depths

Annual

Stratified and including
index reaches and
randomly located sites

Mean
Variance
Rate of change

see list above

Annual

Complete census

Reservoir reach
Reach
recovery as forest
recolonize exposed
reservoir sediments

40

McHenry and Pess

Elwha represent potential reference conditions
of unimpacted spawning habitat.
An additional area of emphasis will be the effect of dam removal on the quality and distribution
of rearing habitats in the Elwha River. Habitat
measurements will focus on the quantifying the
amount, location, and condition of habitat types,
especially in regards to the parameters related to
sediment and wood supply, which are expected
to change following dam removal (Table 5). Field
measurements will include parameters sensitive to
changes in sediment supply such as habitat unit
type and area, residual depth of pools, variation in
bed material grain size, and size and abundance of
wood debris (Beechie et al. 2005). One example of
this is change in residual pool depth. Holding pools
are a critical habitat for most spawning salmonids,
and pool filling is likely to be the most obvious
effect of sediment release after dam removal (Roni
et al. in press). Repeated surveys of thalweg profiles
or channel cross sections can indicate changes in
bed elevation variability (Madej 1999), but these
methods are expensive and yield little information
directly relevant to holding pools or spawning
habitat. Measurement of residual pool filling is a
direct measure of changes in holding habitat quality, but the method is relatively time consuming
to apply over a large area. Measuring changes in
number of pools or residual pool depth is more
efficient than other techniques because surveys
can be conducted rapidly (Beechie et al. 2005),
and the information obtained is a direct measure
of holding habitat availability and quality. Hence,
we propose to monitor residual pool depths in all
pools in accessible mainstem reaches, and record
locations of pools with GPS. Pools will be identified and measured by floating the mainstem and
walking the floodplain channels on an annual basis.
Because we expect the location of many bedrock
pools to remain stable following dam removal, we
will track changes in depths of individual pools
over time. Because some pool locations will shift
frequently with channel migration and movement of wood debris jams, we will also compare
frequency distributions of residual depths in each
reach over time.
Dam removal also restores the natural fluvial
transport process for large wood to the lower and
middle reaches of the Elwha. These reaches have
been historically depleted of in-channel wood
and their riparian forest sources (Johnson 1997,
McHenry et al. 2007). Annual surveys of in-channel

wood snags and accumulations (jams) have been
established in the lower Elwha (below Elwha Dam)
since 2001 (McHenry et al. 2007). Surveys involve
measurement of individual piece characteristics
(e.g., species, size) as well as geographic location.
These provide useful information on the quantity
and quality of large wood and its function for habitat
forming processes. This wood budgeting approach
also provides information on rates of recruitment,
longevity, and movement. These surveys will be
repeated at 5 yr intervals in the lower Elwha. Expansion of the wood budget to include the middle
Elwha would also be an important priority.
Removal of Elwha and Glines Canyon Dams
exposes ~324 ha of former reservoir surface to
fluvial processes. This ~10 rkm of river reaches
will be initially devoid of vegetation and subject
to high rates of sediment transport from the
reservoir surfaces, where the bulk of sediments
have accumulated since dam construction. Initially, channel instability is likely to be high, with
harsh and unstable conditions of spawning and
rearing habitats for both resident and colonizing
fish. The exposed reservoir surfaces will require
extensive revegetation efforts and a restoration
and monitoring plan has been prepared to accomplish this goal (Chenoweth et al. in press).
Current planned monitoring for the reservoir
surfaces focuses on vegetative responses only
(Chenoweth et al. in press).
We propose to implement intensive survey efforts within the newly exposed reservoir surfaces
following dam removal. These areas are likely to
highly dynamic during peak sediment transport
periods with unstable braided channel morphology.
Analysis of historic aerial photographs and existing
bathymetry indicates that both reservoirs were formerly unconstrained alluvial valleys dominated by
island braid channels (DOI et al. 1994, Chenoweth
et al. in press). We will use both remote sensing
and in situ data collection techniques described
throughout this paper to asses changes in physical
and biological habitats (Table 5).
Ecosystem Study Design Considerations
River and floodplain habitats are dynamic, creating
a shifting mosaic of terrestrial and aquatic habitats
(Stanford et al. 2005). Sampling strategies must
therefore accommodate channel movement across
the floodplain by allowing sample locations to
move between years. We stratify habitats into
Elwha River Dam Removal Monitoring

41

three general types (e.g., floodplain, mainstem, and
tributary) and will sample each type throughout
a given study reach for each sample year. In this
way, we will represent all habitat types in each
year regardless of channel movement. Within
each general habitat type we will identify more
specific habitats at the site scale (e.g., pool, riffle,
and glide) and develop a sample design to assure
that sampling of ecosystem components broadly
represent both specific and general habitat types.
We will then sample attributes in the same locations
so that we can document changes over space and
time (e.g., periphyton, benthic invertebrates, fishes
are sampled every nth pool and riffle within a side
channel). We will couple this field sampling design
with channel mapping to characterize spatial and
temporal trends in each ecosystem parameter at
the site, reach, and watershed scale. This sampling
design will allow results to be scaled up from the
site to characterize each reach in aggregate.

Power Analysis
One of the key components to the Elwha monitoring effort is to link the objectives, study design,
and monitoring parameters to expected outcomes.
To address these fundamental monitoring questions, we used a power analysis to examine the
number of years required to detect statistically
significant change, given different effect sizes
(i.e., magnitude of change before and after dam
removal) in a sub-set of the parameters described
above (Figure 3). A priori power analyses such
as these are an important, yet often overlooked,
step in identifying the level of effort, amount of
time, and consequently overall cost necessary for
restoration monitoring. Specifically, we determined
how many years of post-dam removal data would
be needed in order to detect a zero to four-fold (i.e.,
0 to 400 %) effect size, 95% of the time (alpha =
0.05), with a power of 0.80 (i.e., type II error =
0.20). We assumed a before-after-control-impact

Figure 3. Power analysis results for select Elwha River monitoring parameters showing the number of years required to detect
50% to 400% effect sizes, 95% of the time, with an alpha of 0.05.

42

McHenry and Pess

(BACI) design for each parameter and examined
a range of effect sizes.
The parameters chosen for this exercise, and
likely to be part of a final monitoring plan, include
adult salmonid population size, juvenile salmonid
fish density, the number of outmigrating Chinook
smolts, residual pool depth, and benthic invertebrate density. We identified a “control” or reference
reach for each parameter and have between 2–10
yrs of before (pre-removal) data for each. Reference
data for juvenile fish density, residual pool depth,
and invertebrate density were from reaches in the
Quinault River where we will continue to sample
following dam removal. Reference data for adult
Chinook salmon and pink salmon populations
come from the Dungeness River, the nearest large
river system in the Strait of Juan de Fuca. The
correlation in the population size estimates for
each species between the Elwha and Dungeness
populations is over 0.80. These data will also be
collected following dam removal. No reference data
was available for outmigrating Chinoook salmon
smolt counts, so we used data from Elwha River
chum salmon as a proxy. Effect size examined for
each parameter was in increments of a one-fold
(100%) increase. We used a range of 0 to 400%
based on changes seen in other watershed-scale
restoration actions and salmonid response (Solazzi
et al. 2000). The between-year variance for each
metric was calculated by using time series data
for each variable.
The number of years needed to detect a statistically significant change varied considerably
among parameters (Figure 3). Adult Chinook
salmon required the greatest amount of time,
ranging from 7 to 50 yrs, depending upon the
effect size. It will take a little over a decade (two
generations) to detect a significant difference in
Chinook population size following dam removal,
assuming a 250% increase, which is comparable
to other reach and watershed-scale responses by
salmonids (Roni and Quinn 2001, Solazzi et al.
2000). The amount of time required to detect
significant differences in invertebrate density was
the shortest at 1–7 yrs. Juvenile salmonid density
and the number of outmigrating smolts showed
similar time frames between 3 and 28 yrs, while
the amount of time required to detect change in
residual pool depth was 4 to 38 yrs. Assuming an
average effect of 250% for the five parameters
tested here, 3 to 11 yrs of monitoring will be
needed to capture a statistically significant signal

because of the removal of the Elwha River dams.
The number of years required to identify a change
in any of the preceding parameters was qualitatively similar in shape if the alpha was increased
from 0.05 to 0.10 or higher, however the number
of years to detect a change decreased.
Data Analysis
Data analysis of before and after data sets can
be both relatively straightforward and complex
depending upon the model used. Several authors
have suggested simple graphical methods over a
purely statistical approach (see Roni et al. 2005
for a review of the literature). Thus we will rely
upon exploratory graphical analysis to discern
trends in parameters before and after dam removal
and between control and treatment reaches. We
will then use parametric tests such as a t-tests and
ANOVA to compare before and after fish abundance and redd density throughout the watershed
and among reaches. Changes in distribution and
frequency will initially be examined using a chisquare tests (Zar 1999).
One key component to analysis of any of the
preceding variables will be to examine changes
in variation as well as changes in means by quantifying the components of variation (Underwood
1994, Larsen et al. 2004). Several approaches exist
for such analyses including maximum likelihood
analysis, a nested analysis of variance, and trend
detection analysis (Underwood 1994, Larsen et al.
2004). The key to each of these analyses will be to
examine and quantify the variation between years,
among locations, and their respective interactions
in order to help identify the relative importance
of any change due to the treatment. The type of
ANOVA analysis will be a function of the number
of sites, replicates, time intervals, and locational
differences for each of the preceding metrics.
Summary
The removal of dams on the Elwha River offers a
unique opportunity to evaluate the effects of dam
removal and subsequent recovery of formerly
productive aquatic ecosystems that supported large
populations of anadromous salmonids. Although
intentional dam removal of this magnitude has
never been attempted before, it could become more
common as the nation manages an increasingly
aging system of dams. In the western United States
alone, dams on California’s Ventura (Matilija)
Elwha River Dam Removal Monitoring

43

TABLE 6. Summary of past and ongoing Elwha River biological monitoring studies relevant to dam removal.
Topic

Methods

Years

Reference

Nearshore benthos

Diver quadrats along transects

1995

Seavey and Ging 1995
USGS planned for 2008

Macroinvertebrates

Hess Sampling - riffles

1992–1997

Slack sampling – riffles

2004–2006

Munn et al. 1996
Munn et al. 1998
Morley et al. 2008

Salmon escapement

Adult/Redd counts

1984–present

Hiss 1995
WDFW and LEKT
unpublished data

Smolt outmigration

Rotary screw trap

2005–present

LEKT unpublished data

Estuary characterization

Fish seining, invertebrate sampling,
habitat mapping

2006–2008

LEKT, in progress

Nearshore fish use

Beach seining, surface trawling

2005–2007

NOAA, WDFW in progress

Periphyton

AFDM and chlorophyll a

2004–2006

Morley et al. 20008

Water chemistry

Standard techniques

1997
2004–2006

Munn et al. 1998
USGS/NOAA unpublished data

Fish movement

Radio-telemetry in lower Elwha River
by adult Coho

2005–2006

Burke et al. 2008

Fish movement

Acoustic-telemetry of outmigrating
Chinook and coho salmon

2005

U. of Idaho and LEKT

Fish movement

Radio-telemetry in Elwha River
watershed by bull trout and rainbow
trout

2006–present

NPS

Juvenile fish assemblage

Snorkling, electrofishing

1984–present

Pess et al. 2008
Connolly and Brenkman 2008
Unpublished studies by LEKT,
ONP, USGS, and NOAA

Fish genetics

Microsatellite DNA, electrophoresis

1983–present

Reisenbichler and Phelps 1989
Phelps et al. 2001
Winans et al. 2008
LEKT in progress

Fish disease

ELISA and PCR screening

1988–present

Brenkman et al. 2008b

Temperature

continuous recording thermograph

1994–present

LEKT, ONP unpublished data
Connolly and Brenkman 2008

and Washington’s White Salmon (Condit) are
currently being considered for removal. In 2007 a
dam on the Sandy River, Oregon was removed. We
have discussed components of a watershed scale
monitoring plan designed to evaluate the effects
of dam removal on existing salmon populations
and the food webs and habitats of which they are
an integral part. Portions of this plan have already
44

McHenry and Pess

been initiated. However, there remains a major
challenge in scaling the project to the entire basin.
Long term funding outlooks are uncertain for the
existing monitoring efforts (Table 6) as well as
the monitoring outlined herein. If resources to
implement the long-term monitoring strategy
are unavailable, then it is likely that a piecemeal
monitoring strategy will be implemented. As a

result, managers will be limited in their ability to
evaluate the success or failure of dam removal in
relation to the goals and objectives identified in
the Elwha Fisheries Recovery Plan.
Acknowledgements
Numerous individuals and agencies have contributed to the development of concepts in this
paper through their participation in the recovery
planning effort including P. Crain, R. Elofson,
B. Freymond, G. Ging, D. Morrill, D. Poon, R.
Peters, R. Reisenbichler, A. Shaffer, T. Tynan, L.
Literature Cited
Anderson, J. H., P. M. Kiffney, G. R. Pess, and T. P. Quinn.
In press. Distribution and growth of juvenile coho
salmon (Oncorhynchus kisutch) during colonization of
newly accessible habitat. Transactions of the American
Fisheries Society.
Beechie, T. J. and T. H. Sibley. 1997. Relationships between
channel characteristics, woody debris, and fish habitats
in northwestern Washington streams. Transactions of
the American Fisheries Society 126:217-229.
Beechie, T. J., C. N. Veldhuisen, D. E. Schuett-Hames, P.
DeVries, R. H. Conrad, and E. M. Beamer. 2005. Monitoring treatments to reduce sediment and hydrologic
effects from roads. In P. Roni (editor) Methods for
Monitoring Stream and Watershed Restoration, American Fisheries Society, Bethesda, MD. Pp. 35-65.
Bjornn, T. C. and D. W. Reiser. 1991. Habitat requirements of
salmonids in streams. In W. R. Meehan (editor), Influences of forest and rangeland management on salmonid
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