marine mammal monitoring and mitigation plan plans/mar… · considerable resources to...

ADMIRALTY INLET PILOT TIDAL PROJECT

FERC PROJECT NO. 12690

MARINE MAMMAL MONITORING AND

MITIGATION PLAN

Submitted by:

Public Utility District No. 1 of Snohomish County

November 16, 2012

Admiralty Inlet Pilot Tidal Project – FERC No. 12690

FINAL APPLICATION FOR A NEW PILOT PROJECT LICENSE PAGE i

Marine Mammal Monitoring and Mitigation Plan – November 16, 2012

TABLE OF CONTENTS

1.0 INTRODUCTION.............................................................................................................. 1

2.0 PROJECT DESCRIPTION .............................................................................................. 1

3.0 BACKGROUND INFORMATION ................................................................................. 4

3.1 Marine Mammal Presence in Admiralty Inlet .................................................................. 4

3.2 Harbor Porpoise Echolocation Activity ........................................................................... 5

3.3 Pre-Installation Acoustic Effects Estimate ....................................................................... 7

3.3.1 Marine Current Turbines SeaGen Demonstration .................................................... 8

3.3.2 European Marine Energy Center .............................................................................. 8

3.4 Pre-Installation Noise Detection Estimate ....................................................................... 8

4.0 PLAN OBJECTIVES AND GOALS .............................................................................. 14

5.0 POST-INSTALLATION MONITORING AND MITIGATION PLAN .................... 15

5.1 Pinniped Response to Turbine Presence ........................................................................ 17

5.1.1 Objective ................................................................................................................. 17

5.1.2 Data Collection ....................................................................................................... 17

5.1.3 Data Analysis .......................................................................................................... 19

5.1.4 Reporting and Adaptive Management .................................................................... 20

5.2 Harbor Porpoise Response to Turbine Presence ............................................................ 20

5.2.1 Objective ................................................................................................................. 20

5.2.2 Data Collection ....................................................................................................... 21

5.2.3 Data Analysis .......................................................................................................... 21


5.3 Killer Whale Response to Turbine Presence .................................................................. 23

5.3.1 Objective ................................................................................................................. 23

5.3.2 Data Collection ....................................................................................................... 23

5.3.3 Data Analysis .......................................................................................................... 25


6.0 APPROACH TO ADAPTIVE MANAGEMENT AND MITIGATION .................... 26

7.0 REFERENCES ................................................................................................................. 29


FINAL APPLICATION FOR A NEW PILOT PROJECT LICENSE PAGE ii


Attachment 1 – Carlson, T.J., J.L. Elster, M.E. Jones, B.E. Watson, A.E. Copping, M. Watkins,

R. Jepsen, and K. Metzinger (2012) Assessment of strike of adult killer whales by an OpenHydro

tidal turbine blade, Pacific Northwest National Laboratory technical report, PNNL-21177

Attachment 2 – November 15, 2012, draft “A framework for detection of tidal turbine sound: A

pre-installation case study for Admiralty Inlet, Puget Sound, Washington (USA)”

Attachment 3 – Power Analysis for Ability to Detect Changes related to Southern Resident

Killer Whales

LIST OF FIGURES

Figure 1 – Conceptual instrumentation layout (fixed and recoverable). Instrumentation shown on

a 4th Generation turbine (higher rotor solidity than 7th Generation turbine). The general

dimensions of the subsea based and support structure are approximately constant between

technology generations for the same rotor size............................................................................... 2

Figure 2 – Turbine deployment location in northern Admiralty Inlet. Blue triangles denote

turbines, each of which is connected back to shore via a separate power cable. Dashed red

polygon to the east of Keystone Harbor is a marine protected area. .............................................. 3

Figure 3 – Typical landmark sequence ........................................................................................... 6

Figure 4 – Porpoise detection positive minutes per day, as classified by different

instrument/software combinations (Collar et al., 2012). Notably, DPM statistics depend

significantly on the type of instrument (T-POD vs. C-POD) and version of software used for the

analysis. This complicates comparison of data between projects where different versions of the

software are employed. ................................................................................................................... 7

Figure 5 – Probability of mid-frequency cetacean (killer whale) detecting turbine noise (30 m

depth relative to surface). .............................................................................................................. 11

Figure 6 – Probability of high-frequency cetacean (harbor porpoise) detecting turbine noise (30

m depth relative to surface)........................................................................................................... 12

Figure 7 – Probability of pinniped (harbor seal) detecting turbine noise (30 m depth relative to

surface). ......................................................................................................................................... 13

Figure 8 – Admiralty Inlet showing possible study area boundaries (500 m or 1000 m) and

probable observer location. ........................................................................................................... 16

Figure 9 – Scan procedure for pinniped monitoring ..................................................................... 19

Figure 10 – Passive acoustic array on OpenHydro turbine. Hydrophone configuration is

preliminary. ................................................................................................................................... 24

MARINE MAMMAL MONITORING AND MITIGATION PLAN for the Admiralty Inlet Pilot Tidal Project

FINAL APPLICATION FOR A NEW PILOT PROJECT LICENSE PAGE 1


1.0 INTRODUCTION

Interactions between marine mammals and tidal turbines are an area of high uncertainty (Polagye

et al., 2011) and pilot projects in Europe, Canada, and the United States have devoted

considerable resources to characterizing how installation and operation of tidal energy projects

affects marine mammals. While marine mammals may respond to any number of cues associated

with project operation, sound is, in many cases, likely to be first cue detected. Based on pre-

installation estimates, sound from project operation is not expected to rise to a level that

constitutes injury, but will periodically rise to a level that may cause behavioral changes over

small spatial scales. Marine mammal behavioral responsiveness to noise is a well-known, but not

well-understood in terms of relating a particular noise to a specific response (e.g., as discussed in

Southall et al., 2007).

The Marine Mammal Monitoring and Mitigation Plan provides studies to evaluate behavioral

changes in marine mammals associated with project operation. These are partitioned by

functional group (i.e., pinnipeds, mid-frequency cetaceans, high-frequency cetaceans). In all

cases, the hypothesis being tested is similar – marine mammals may respond to the sound from

project operation or prey aggregations through attraction, avoidance, or change in behavioral

state. However, the specific approach, duration of observations, and analyses to be undertaken,

vary by functional group based on the statistical power to detect change, need to ensure proper

resource protection, and suitable monitoring technologies.

Through adaptive management, this information will provide for proper resource protection of

marine mammals. Additional details regarding instrumentation on the turbines are presented in

the Monitoring Plan Summary.

2.0 PROJECT DESCRIPTION

The demonstration project proposed by Snohomish County Public Utility District consists of two

turbines manufactured by OpenHydro, an Irish turbine developer. Each of these turbines has a 6

m diameter outer shroud, as shown in Figure 1. These will be deployed on a gravity tri-frame,

with tubular cans contacting the seabed at the vertices. Turbine hub height will be 10 m above

the seabed. The OpenHydro turbines are fixed-pitch, high-solidity rotors with an open center.

The rotor cassette is the single moving part and is supported by water-lubricated bearings. A

permanent magnet generator is contained in the shroud surrounding the blades. Anti-fouling

coatings are applied to the interior surface of the shroud, hub, and rotor blades, but the gravity

frame (steel, ballasted by concrete and aggregate) is left bare. The turbine shown in Figure 1

represents the 6 m version of 4th

Generation technology. The turbines deployed in Puget Sound

will be 6 m variants of 7th

Generation technology – the principle differences being fewer blades

and more streamlined central hub.

The turbines will be deployed in northern Admiralty Inlet, Puget Sound, Washington. Admiralty

Inlet is a constricted sill separating the deep Main Basin of Puget Sound from the Straits of Juan

de Fuca and Straits of Georgia. At the narrowest point, between Admiralty Head and Point

Wilson, the channel is approximately 5 km wide and 70 m deep. Excepting a small exchange

through Deception Pass, the entire tidal prism of Puget Sound passes through this constriction,




giving rise to tidal currents that routinely exceed 3 m/s (6 knots) at mid-water. The project site is

approximately 1 km SE of Admiralty Head in 55 m of water (Figure 2). The project location was

chosen on the basis of strong tidal currents (intensified by the proximity to the headland),

negligible seabed slope (necessary to deploy the gravity foundation), separation from high vessel

traffic areas (federal navigation lanes, ferry route), and ease of cable routing back to shore.

Each turbine will be connected to shore by a separate power cable. These cables will also

provide power for monitoring instrumentation and fiber optic communication with the turbine

and monitoring instrumentation. Turbine monitoring systems are grouped into two categories –

instruments that will be deployed for the duration of the demonstration project (fixed) and

instruments that will be periodically recovered for maintenance (recoverable). This will be

enabled by an Adaptable Monitoring Package (AMP) consisting of a self-aligning frame with

instrumentation and a wet-mate power and fiber connector.

Figure 1 – Conceptual instrumentation layout (fixed and recoverable). Instrumentation shown on a 4th

Generation turbine (higher rotor solidity than 7th Generation turbine). The general dimensions of the subsea

based and support structure are approximately constant between technology generations for the same rotor

size.




Figure 2 – Turbine deployment location in northern Admiralty Inlet. Blue triangles denote turbines, each of which is connected back to shore via a

separate power cable. Dashed red polygon to the east of Keystone Harbor is a marine protected area.




3.0 BACKGROUND INFORMATION

3.1 Marine Mammal Presence in Admiralty Inlet

As described in the District’s Final License Application (Snohomish PUD, 2012), marine

mammal species reported to occur in central Puget Sound include: Southern Resident Killer

Whale (SRKW) (Orcinus orca), humpback whale (Megaptera novaeangliae), Steller sea lion

(Eumetopias jubatus), harbor porpoise (Phocoena phocoena), Dall’s porpoise (Phocoenoides

dalli), Minke whale (Balaenoptera acutorostrata), gray whale (Eschrichtius robustus),

California sea lion (Zalophus californianus), harbor seal (Phoca vitulina), and northern elephant

seal (Mirounga angustirostris).

Programs to document presence of marine mammals in Puget Sound include twelve years of

vessel surveys conducted by the Washington Department of Fish and Wildlife (WDFW). These

surveys were conducted basin-wide, and WDFW has compiled the results in a spatially rectified

database. Harbor seals accounted for 687 sightings in Admiralty Inlet followed by harbor

porpoise (67 sightings), Dall’s porpoise (16 sightings), river otter (12 sightings), killer whale (10

sightings), and California sea lion (8 sightings) (WDFW, 2006). There are also several known

pinniped haulout locations in the vicinity of Admiralty Inlet, the nearest being to the southeast

for the proposed location for the demonstration project.

Harbor seals are the most common, widely distributed pinnipeds found in Washington waters

and represented 86 percent of the marine mammals observed by WDFW between 1992 and 2004

(WDFW 2006). Jeffries et al. (2000) identified 13 harbor seal haulout locations in Admiralty

Inlet. Harbor porpoise, the second most commonly observed marine mammal in Puget Sound,

are relatively common and can be observed in the region year-round (Calambokidis and Baird,

1994; further discussion in §3.2). Seasonal changes in abundance along the west coast have been

noted; however, movement patterns are not fully understood. In recent years, the population of

harbor porpoise in Puget Sound has increased significantly relative to the 1970’s. The factors

underlying this increase are not entirely understood.

The Southern Resident killer whale (SRKW) is one of four distinct population segments of

resident killer whales in the northeastern Pacific, whose range extends from Alaska to California

(Krahn et al., 2002; Krahn et al., 2004). This distinct population segment consists of three pods

(one or more matriline groups traveling together), designated J, K, and L pods, that reside for

part of the year in the inland waterways of Washington State and British Columbia (Strait of

Georgia, Strait of Juan de Fuca, and Puget Sound), principally during the late spring, summer,

and fall (Bigg, 1982; Ford et al., 2000; Krahn et al., 2002). Pods can be found in Puget Sound

year-round, but during fall, winter and spring, SRKW are more prone to excursions out of Puget

Sound and can be seen as far south as California. Winter and early spring movements and

distribution are largely unknown for the population (NMFS, 2008). The majority of sightings

occur at locations off San Juan Island where there have been 750 to 1,550 sightings from 1993 to

2005. At locations in Admiralty Inlet, in the vicinity of the Project, between 6 and 25 sightings of

SRKW were recorded annually from 1990 to 2005 (NMFS, 2009). From January 1990 through

December 2008, the Orca Master database recorded 2,532 sightings of SRKW in Puget Sound

“proper” (south of Deception Pass and Admiralty Inlet), and of those, 196 occurred within 5

nautical miles (9 km) of the proposed Project (Whale Museum, 2009).




Between October 2009 and April 2010 land- and boat-based observations of marine mammals

were made in the study area (a 5 nautical mile (9 km) radius around the proposed Project

deployment site). Overall, 2,145 sighting locations were recorded of seven marine mammal

species. Harbor seals were observed most often, occurring on 95 percent of survey days and

accounted for 49 percent of all sightings, with a total of 1,041 sightings recorded on 110 separate

days (Tollit et al., 2010).

Members of all three SRKW pods were identified during boat-based observations. In summary, a

total of 11.5 hours of focal sampling were conducted. During this time, SRKW spent most of

their time in the study area traveling (74 percent), while the remainder of the time was spent

foraging (21 percent) and socializing (5 percent) (Tollit et al., 2010). Dive depth information was

collected using a vertical hydrophone array deployed from a boat. During seven SRKW transits,

a total of 655 calls and clicks were localized at depths from the surface down to 142 meters;

however, 80 percent of the vocalizations were produced at depths of 30 meters or less, with little

difference in average depth by behavior category. During the closest approach to the proposed

Project site (October 21, 2009), while the focal group was categorized as foraging, depths from

23 to 58 meters were recorded from eight calls and clicks. The focal studies indicated that there

is great variability in SRKW vocalization rates when transiting through the study area (0 to 92

percent of recording time). Periods with little or no vocal activity were witnessed, most notably

on October 10, 2009, when the pods were described as undertaking slow (thought to be restful)

travel (Tollit et al. 2010).

3.2 Harbor Porpoise Echolocation Activity

Pre-installation studies intended to characterize the physical and biological variability in northern

Admiralty Inlet have included cetacean click detectors (C-PODs, Chelonia, Ltd.). These

specialized hydrophones detect clicks, which may be of cetacean origin, and log characteristic

information. In post-processing, a classifier is used to detect trains that are of cetacean origin (as

distinct from clicks caused by sediment transport, boat sonars, etc.). Seasonal variability in

harbor porpoise activity is shown in Figure 4, in terms of detection positive minutes per day (i.e.,

the number of minutes each day in which porpoise are detected). In absolute terms, porpoise

presence can be quite high, approaching 800 DPM/day (more than 50% of all minutes).

Significant seasonal variability is observed, as well as a pronounced diel inequality (presence

much more likely during the night than during the day). These strong patterns of activity and

high relative abundance offer potentially greater ability to detect behavioral changes associated

with the operation of tidal turbines at this location.

Additionally, “landmark” activity recorded by C-PODs provides a mechanism to directly

evaluate harbor porpoise awareness of the turbines. A “landmark” is defined as a sequence of

echolocation click trains with linearly decreasing inter-click intervals (ICI). This pattern

indicates cetaceans approaching the instrument and actively echolocating at the C-POD, its

mooring, or other nearby object (Chelonia user guide). The name for the behavior is derived

from the use of such “landmarks” by harbor porpoises for the purpose of navigation. Landmark

sequences are identified by cpod.exe software and must be analyzed manually for validity. A

typical sequence indicative of landmark behavior recorded during the deployment is depicted in

Figure 3. These sequences can be used to roughly estimate the distance at which porpoises

becomes aware of their echolocation target (Chelonia user guide).




Figure 3 – Typical landmark sequence

A total of six highly likely landmark sequences were identified in the year of data from May

2010 – May 2011 from a single C-POD (Unit #718). As given by the equation above, the

average initial distance from the instrumentation package at the start of a landmark sequence was

approximately 60 m. The sequences also indicate approaches to within 20 m of the

instrumentation, on average. The farthest distance at which a landmark sequence begins is

estimated to be approximately 90 m.




Figure 4 – Porpoise detection positive minutes per day, as classified by different instrument/software

combinations (Collar et al., 2012). Notably, DPM statistics depend significantly on the type of instrument (T-

POD vs. C-POD) and version of software used for the analysis. This complicates comparison of data between

projects where different versions of the software are employed.

3.3 Pre-Installation Acoustic Effects Estimate

There has been limited, though high profile, monitoring of marine mammals at other tidal energy

projects, principally for the Marine Current Turbines (MCT) SeaGen demonstration in

Strangford Lough, Northern Ireland and the European Marine Energy Center in the Orkney

Islands, Scotland. Other projects that have undertaken pre-installation baseline surveys of marine

mammal population and presence, similar to those described in § 3.1.




3.3.1 Marine Current Turbines SeaGen Demonstration

For the Marine Current Turbines SeaGen demonstration in Strangford Lough, Northern Ireland,

the two principal marine mammal concerns were, arguably, that (1) the sound produced by the

turbine might create a barrier to harbor porpoise moving between the inner and outer Lough

through Strangford Narrows and (2) that the rotating turbine might injure or kill harbor seals.

The potential for an acoustic barrier for harbor porpoise was assessed using T-PODs (the older,

analog version of the C-POD click detectors used for this project). Monitoring of harbor porpoise

echolocation activity took place before installation, during construction (which involved bedrock

drilling to secure the jacketed pile foundation), and during operation. Harbor porpoise

echolocation activity declined during construction activities, but returned to pre-installation

levels thereafter, with no statistically significant differences between presence in the inner and

outer Lough before construction and after operation began (Keenan, 2011). Additionally, marine

mammal observers on shore and pile have confirmed transits of seals and harbor porpoise occur

past the turbine while it is in operation, indicating the absence of a significant barrier effect.

To mitigate against potential mortality or injury to a protected population of harbor seals, the

local regulator and MCT agreed to shut down the turbine when harbor seals are within a

specified distance (currently, less than 100 m), as detected initially by a shoreline observer and

currently by monitoring of active sonar. No seal mortality has occurred, but, because no

monitoring of seal-turbine interactions has been possible, the actual risk to harbor seals remains

unknown.

Carlson et al. (2012, appended) includes the results of recent research, modeling the

consequences of collisions between killer whales and OpenHydro turbines in Admiralty Inlet.

The results of this analysis suggest that should collision/strike occur, the consequences would not

be severe. An analysis of this type was not undertaken for the SeaGen project and is a crucial

difference between the emphasis on mitigation undertaken for that projects and the emphasis on

monitoring proposed for this project.

3.3.2 European Marine Energy Centre

The European Marine Energy Centre (EMEC) is the leading worldwide test facility for tidal

turbines. There are presently, multiple turbines under tests at the Fall of Warness, including a 6

m OpenHydro turbine mounted to a pile foundation (rather than a gravity base). Several species

of marine mammals, including killer whales, are present in the Fall of Warness, but shoreline

observers have not monitored them approaching the turbines (personal communication, Sue Barr,

OpenHydro, Ltd.). Within the past year, EMEC has begun a more comprehensive marine

mammal monitoring program, but the results are not yet available.

3.4 Pre-Installation Noise Detection Estimate

Marine mammal monitoring undertaken for both the SeaGen project and at the European Marine

Energy Center have involved shoreline counts of marine mammals, stratifying these by spatial

position (e.g., grid density) to evaluate potential behavioral changes as a consequence of turbine




operation. For these studies, observations have been further stratified by turbine operating state –

either “on” or “off”.

The most likely mechanism for marine mammal behavioral changes over a significant area is the

potential for disturbance by turbine sound. As discussed in Southall et al. (2007), marine

mammal behavioral responses to sound depend upon multiple factors, including the intensity and

frequency of the received sound, behavioral state at the time sound is detected, and prior

exposure to similar sounds. In areas of with variable ambient noise levels, such as Admiralty

Inlet, the distance from a source that a sound would be detected is variable in time. Further,

experience from the wind industry suggests that the sound produced by tidal turbines will vary as

a function of power generated. Clearly, stratification of marine mammal counts by whether a

turbine is “on” or “off” neglects most of these factors and is likely insufficient to detect what, at

the pilot scale, may be subtle behavioral changes.

A key consideration in the development of marine mammal monitoring plans is the spatial extent

of the area to be monitored. On one hand, surveying as broad an area as possible is desirable, in

order to maximize the number of marine mammals observed. On the other, surveying as small an

area as possible maximizes the spatial resolution of the information collected. This is a classic

range-resolution trade-off and suggests that surveys be designed to collect information at high

resolution within the area that behavioral changes are likely to be observed.

Polagye et al. (in prep) proposes a framework for evaluating the detection of turbine sound by

marine mammals, with a specific application to the District’s proposed demonstration project in

northern Admiralty Inlet. It establishes an upper limit on the zone of behavioral responsiveness

by estimating the zone of audibility (or, zone of detection) for turbine sound. Turbine sound is

said to be audible if received levels (RL) exceed noise levels (NL), resulting in a positive signal

excess (SE), as

.

Received levels are related to the source level (SL) of the sound as

where TL is the transmission loss and AG is the auditory gain of the receiver. Further, a sound

will only be detected, regardless of the signal excess, if the received level exceeds species-

specific hearing thresholds.

Even with a number of simplifying assumptions, there are a number of inter-related variables

involved:

Noise level: varies by frequency and in time. Low frequency ambient noise (i.e., < 1 kHz)

is independent of tidal current velocity. However, high frequency ambient noise, which

includes sound produced by mobilization of coarse sediments, does depend on tidal

current velocity.

Source level: varies by frequency and in time, in proportion to power generation, which

is, in turn, dependent on tidal current velocity.

NLRLSE

AGTLSLRL




Transmission loss: varies by frequency and with position in three-dimensional space

relative to the source.

Hearing threshold: varies by frequency and by species.

Polagye et al. (in prep) proposes a framework to evaluate the probability of a particular class of

marine mammal (e.g., mid-frequency cetacean) detecting turbine sound in a particular one-third

octave band at a particular location in space over all possible ambient noise levels and received

levels as:

.

The terms correspond to the following:

: the probability of sound in a particular one-third octave band (f) being

detected at a particular position in space (x,y,z).

: detection of sound (1 = detection, 0 = no detection) for a particular

combination of noise level (NL), received level (RL), and species/frequency-specific

hearing threshold (HT) for a particular frequency and position in space.

: the probability of a particular noise level occurring as a particular

frequency, given a received level (for frequencies greater than 1 kHz, these are related via

current velocity).

: the probability of a particular received level occurring for a particular frequency

and position in space.

The summation results in an overall probability of detecting turbine sound at a given frequency

and position in space. The following series of figures visualize the results by marine mammal

functional group for the area in the vicinity of the two proposed OpenHydro turbines. For each

functional group, six one-third octave bands are visualized. For the first four frequencies (50 Hz,

160 Hz, 500 Hz, and 2000 Hz), these represent relative peaks in the turbine sound spectrum. For

the last two (8 kHz and 25 kHz), these represent important frequencies for marine mammal

communications.

These results are, by necessity, subject to a number of assumptions (e.g., the variation of turbine

sound intensity with tidal currents, uncertainty in hearing thresholds). Evaluating the validity of

the sound production assumptions is a key aspect of the Acoustic Monitoring and Mitigation

Plan. The results shown here represent updated hearing threshold information from that

presented in the appended, draft version of Polagye et al., which was supplied by Marla Holt at

the Northwest Fisheries Science Center. This information will be incorporated into a revised

version of the manuscript in the near future.

i

i

j

ijijfzyxRLpRLNLpHTRLNLddp ,,

,,,

fzyxdp

,,,

HTRLNLdij,,

ijRLNLp

iRLp




Figure 5 – Probability of mid-frequency cetacean (killer whale) detecting turbine noise (30 m depth relative to

surface) (Polagye et al., in prep).




Figure 6 – Probability of high-frequency cetacean (harbor porpoise) detecting turbine noise (30 m depth

relative to surface) (Polagye et al., in prep). Note: due to harbor porpoise hearing sensitivity, no turbine sound

at 50 Hz or 160 Hz is likely to be detected at any range and under any operating condition.




Figure 7 – Probability of pinniped (harbor seal) detecting turbine noise (30 m depth relative to surface).

Detection of turbine sound by three marine mammal classes is presented in Figure 5-Figure 7. A

single species has been chosen as having representative hearing thresholds for each class:




Mid-frequency cetacean: killer whale

High-frequency cetacean: harbor porpoise

Pinniped: harbor seal

Low-frequency cetaceans are not included in this assessment because audiograms do not exist

for this class of marine mammal (Southall et al., 2007).

For mid- and high-frequency cetaceans, sound detection is most probable for the one-third octave

band centered at 500 Hz. The probability of sound detection falls to less than 20% within 1 km

of the turbines. For pinnipeds, sound detection is most probable for the one-third octave band

centered at 160 Hz and is reasonably probable to a range of several kilometers.

Since detection of sound is a necessary, but not sufficient, condition for a behavioral response

(particularly for pinnipeds), these results suggest that the area of study for the marine mammal

plan should be on the order of 1 km in radius, centered on the turbines.

4.0 PLAN OBJECTIVES AND GOALS

The goal of the Marine Mammal Monitoring and Mitigation Plan is to detect and observe marine

mammals in the Project area, during turbine installation, operations, and removal in order to

provide information about potential avoidance of the turbines, attraction to the turbines, or

changes to activity state caused by the turbine. Another goal is to then use this information to

modify the project if needed to provide mitigation and resource protection.

The plan seeks to test three hypotheses, and, in doing so, reduce the existing uncertainty around

the interactions between marine mammals and tidal turbines. These are arranged around three

functional groups: pinnipeds (specifically harbor seals and Steller sea lions), harbor porpoise,

and killer whales (Southern Resident and transient). These species represent those groups that are

present in the Project area at levels sufficient to undertake robust analyses (Tollit et al., 2010).

Hypothesis 1: Pinnipeds may respond to the acoustic stressors from turbine operations or

prey aggregations through attraction or avoidance.

Hypothesis 2: Harbor porpoise may respond to the acoustic stressors or prey aggregations

through attraction or avoidance. Their high rate of occurrence in the Project area provides

an opportunity to conduct studies with greater statistical power than for other marine

mammals.

Hypothesis 3: Killer whales may respond to the acoustic stressors or prey aggregations in

the vicinity of the turbine through attraction, avoidance, or change in activity state. Their

endangered and iconic status warrants special consideration.

To accomplish these goals, the District will conduct the Monitoring and Mitigation Plans laid out

in this document and consult with the Admiralty Inlet Marine Aquatic Resource Committee

(MARC) to consider modification to this Plan and the project in response to the results of marine

mammal monitoring efforts or acoustic monitoring efforts.

Land and acoustic-based observations of marine mammals in the Project vicinity will

compliment efforts and expertise already in place, as represented by the Orca Network, Beam




Reach Marine Science and Sustainability School, National Oceanic and Atmospheric

Administration (NOAA) and the Whale Museum.

Additionally, during project installation and removal the District will follow NOAA guidelines

for vessel operations around marine mammals. Specifically, if a listed cetacean occurs within

500 meters, or listed pinniped occurs within 100 meters of an installation or removal vessel,

installation or removal operations will be halted. Once the listed cetacean or pinniped leaves the

vicinity, installation or removal operations will resume.

5.0 POST-INSTALLATION MONITORING AND MITIGATION PLAN

Marine mammal behavioral responsiveness to noise is a well-known, but not well-understood in

terms of relating a particular sound to a specific response (e.g., as discussed in Southall et al.,

2007). The acoustic stressor from project operation is, however, likely to be the first cue

associated with the project that is detected by marine mammals. The zone of audibility

establishes an upper bound on the zone of responsiveness. As described in Polagye et al. (in

prep), given assumptions regarding the time variation of turbine noise and pre-installation

measurements of ambient noise, the zone of audibility likely extends no further than a few

hundred meters around the turbines for mid-frequency cetaceans, high-frequency cetacean, and

pinnipeds. The zone of audibility for low-frequency cetaceans is likely to be somewhat greater,

but cannot be estimated with certainty due to a lack of audiogram information for this class of

marine mammal. This also precludes quantitative studies of this functional group. A clear

difference between these proposed studies and past marine mammal studies for tidal energy

projects is that observations will be stratified by stressor (e.g., signal excess of turbine sound)

rather than simply observation of the proximity of a marine mammal to the turbines. A

combination of scan sampling (pinnipeds) and continuous focal individual/group sampling (killer

whales and harbor porpoise) will be used by land-based observers.

All observations are restricted to a circular study area with radius referenced to the “acoustic

center” of the project (i.e., a point midway between the two turbines). The study area radius will

be between 500 m and 1000 m (Figure 8) The study area extent needs to balance between

identifying targets before they enter the zone of audibility (larger study area preferred) and well-

resolved observations of marine mammals in time and space (smaller study area preferred) . The

study area will be finalized in consultation with the MARC following a demonstration of marine

mammal monitoring techniques in the fall of 2012. This will consist of a day of monitoring in

which trained observers will follow the protocols outlined in the following plans using either

reticle binoculars (lower accuracy, easier to use) or theodolite (higher accuracy, hard to use).

High definition video capture will also be obtained to evaluate utility for tracking groups

referenced to theodolite/reticule observations.




Figure 8 – Admiralty Inlet showing possible study area boundaries (500 m or 1000 m) and probable observer

location.

All observations are stratified by the zone of audibility for each functional group (pinnipeds,

harbor porpoise, and killer whales). This reduces variations in ambient noise and tidal currents to

a single variable, simplifying presentation and interpretation of results. Information about the

location of vessels and turbine power generation state will be used to develop time series

estimates for turbine sound and ambient noise in one-third octave bands. These will be combined

with knowledge of marine mammal hearing thresholds to establish the zone of audibility.

Specifically, turbine sound will be estimated using the information from the Acoustic Monitoring

and Mitigation Plan that relates source levels (radiated noise levels at 1 m) to power generation

state. Ambient noise (frequencies < 1 kHz) will be estimated from vessel presence recorded by

an Automatic Identification System receiver using a frequency-dependent model based on the

broadband model described in Bassett et al. (in press). Higher frequency sound (i.e., > 1 kHz) is

dependent on current velocity (Bassett et al., submitted), but the zone of audibility is likely to be

greatest below 1 kHz (Polagye et al., in prep), meaning that this dependence can be neglected.

Shoreline marine mammal observers will not have foreknowledge of the zone of audibility,

meaning that this will be a blind observation, reducing potential for bias.




5.1 Pinniped Response to Turbine Presence

5.1.1 Objective

Pinniped responsiveness to turbine noise will firstly be evaluated by 2-3 experienced shoreline

marine mammal observers positioned on Admiralty Head (lower gun emplacements on the bluffs

at Fort Casey, 48 09.286N, -122 40.686). Observations will focus on identifying attraction or

avoidance within the zone of detection for turbine noise. All pinnipeds (e.g., harbor seals, Steller

sea lions) will be categorized within this function group to increase sample size and, therefore,

statistical power to detect changes. The objective is to detect and observe pinnipeds in the project

area during turbine installation, operation, and removal in order to provide information about

potential attraction to the turbines, avoidance of the turbines, or changes to activity state within

the zone of detection for turbine noise. This information will then be used to modify the Plan or

project operations, if needed, to provide mitigation and resource protection.

5.1.2 Data Collection

Equipment Description

The locations of pinnipeds identified during scans will be determined using either a tripod

mounted theodolite (±2 m accuracy at a range of 2 km) or reticle binoculars. The decision of

whether to use a theodolite (higher accuracy, more difficult to use) or reticle binoculars (lower

accuracy, easier to use) will be determined, in consultation with the MARC, following a field test

in the fall of 2012. Unlike studies of Southern Resident killer whales and harbor porpoise, video

information will not be collected during pinnipeds scans since prior experience (pers. comm., D.

Tollit, SMRU, Ltd.) suggests that observations at this distance are unlikely to be able to reliably

determine behavioral state for pinnipeds in water.

Survey Procedure

The specific locations of pinnipeds within study area will be determined by theodolite or reticle

binoculars using a scan sampling technique. Scan sampling is best done with a sample interval as

short as possible (Mann, 1999). Given the small area under observation, seven minute scan

blocks will be undertaken (five minutes scanning, followed by two minutes rest). Each scan will

consist of observations from left to right across the study area in a systematic manner, recording

the locations of all pinnipeds present. Ad libitum information on behavior (e.g., feeding events)

and group structure (if applicable) will be recorded when possible in the event that an odd

behavioral event is observed. Prevailing metocean conditions will also be noted for each scan

(Laake et al., 1998).

For each observation, location, species, and group size will be recorded. Only one location per

individual or group will be recorded per scan period (e.g., a seal siting on the surface is recorded

once during a five minute scan period).

Observations will be undertaken during daylight hours, at most light precipitation, fog less than

Category II, and Beaufort Sea State less than 4. Scan effectiveness is likely to be lower when

wind, rain, or currents are roughening the sea surface. There will be 400 hours of total

observation effort over one calendar year. This is similar to marine mammal observations




undertaken by Marine Current Turbines for the SeaGren process in Strangford Lough, Northern

Ireland (200 hours total observations) and pre-installation observations to establish species

presence/absence in Admiralty Inlet. Observations are likely to be more difficult during the

winter than in the summer, given regional weather patterns. Consequently, observers will attempt

250 hours of observations during winter (Oct. 1 – Mar. 31) and 150 hours of observations during

summer (Apr. 1 – Sep. 30). During winter months, the percentage of attempted hours with good

observations is likely to be lower than the summer (i.e., the total number of “good” observations

should be the same between winter and summer, even though more observer effort is scheduled

for winter months).

The observation period will be 6 hours per day, as limited by available daylight during the winter

months. Observations in the winter and summer will be distributed among months (i.e.,

approximately 7 days each month during the winter, 4 days each month during summer). The

timing of these observations will be selected in order to obtain data over a range of tidal

conditions (equal stratification is not possible, given that lower tidal currents are more probable

than high tidal currents), with preference given to obtaining data during strong currents when the

sound produced by the turbine is likely to be greatest.

Scans will be discontinued to undertake (short) periods of focal animal follows if killer whales or

harbor porpoise are detected within the study area (see flow chart in Figure 9).

During scans, vessel traffic will be monitored by an Automatic Identification System (AIS) on

Admiralty Head. Turbine power generation state will be monitored using the turbine Supervisory

Control and Data Acquisition (SCADA) system. This information will be used to estimate

ambient noise and sound produced by the turbines during a scan.




Figure 9 – Scan procedure for pinniped monitoring

5.1.3 Data Analysis

A time series of pinniped locations will be developed from theodolite/reticle binocular data.

These locations will be mapped to grid cells around the turbines to quantify presence/absence.

Initially, the grid spacing will be 100 m square (approximately 80 grid cells in the study area),

but this may be refined during analysis based on consultation with the MARC. By retaining the

raw time series data, it will be possible to remap observations to different grid resolutions, as

needed.

Observations will be stratified by month, time of day, and presence of prey species in the vicinity

of the turbines (as informed by the Near-turbine Monitoring and Mitigation Plan). The objective

of the analysis will be to evaluate whether pinniped presence/absence is related to the signal

excess of sound produced by the turbine. The relation between presence/absence and model

variables (e.g., month, time of day, signal excess) is likely to be non-linear. Given the limited

temporal and spatial separation between data points, the collected data is likely to violate

assumptions of independence for many statistical tests. This correlation between data points will

therefore need to be taken into account during statistical analysis and de-correlation time scales

will be evaluated. Generalized Additive Models (GAM) have been used successfully on non-

linear marine mammal data with final standard errors and p-values adjusted with Generalized




Estimating Equations (GEE) to deal with the auto-correlation of data points (Keenan et al. 2011).

A similar approach will likely be required here.

5.1.4 Reporting and Adaptive Management

Prior to the start of pinniped observations, the MARC will be consulted to establish the extent of

the study area, based on the final results of the sound detection analysis in Polagye et al. (in

prep) and results of observation trials in the fall of 2012.

Pinniped surveys will commence once the project is operational, with a preliminary, oral report

made to the MARC within 60 days of turbine installation. On a quarterly basis, a report will be

provided to the MARC describing number and species of pinnipeds observed within the survey

area and the device operating state during these observations. Final written and oral reports will

be made to the MARC within 120 days of survey completion (one calendar year of operation)

describing the observations, statistical modeling approach, and results.

If the results of the Acoustic Monitoring and Mitigation Plan indicate that the extent of

detectable turbine noise is greater or less than indicated by pre-installation estimates (i.e.,

Polagye et al., in prep), then the survey area may be expanded or contracted with the

concurrence of the MARC.

Pinnipeds are food motivated. If the Near-turbine Monitoring and Mitigation Plan indicates that

prey is aggregating around the turbines after the first calendar year of pinniped observations is

complete (and such aggregations did not occur during the first calendar year), a short-term

pinniped study (e.g., 2+ weeks observations) will be conducted to evaluate whether prey

aggregations are affecting behavior in the vicinity of the Project. The specific study scope will be

developed in consultation with the MARC. In conjunction with the MARC and with NMFS

approval, as provided in section 6.0, this information will be used to inform project

modifications, where necessary, to provide mitigation and resource protection.

5.2 Harbor Porpoise Response to Turbine Presence

5.2.1 Objective

Pre-installation acoustic monitoring indicates a high level of porpoise activity at this location

(Tollit et al., 2010; Cavagnaro et al., in prep) and porpoise are known to be more adverse to

acoustic disturbance than other marine mammals (though, at this site, there may be habituation to

sound from shipping traffic – Polagye et al., in prep). Focal animal sampling (the type of

sampling being conducted for this Plan), has greater statistical power to detect change than scan

sampling and is more feasible for cetaceans than pinnipeds. Consequently, observations of

harbor porpoise may have greater statistical power to detect behavioral change than observations

of other marine mammals. Additionally, harbor porpoise echolocation can be used to provide

additional information about activity state and awareness of the turbines. Therefore, the objective

of this study is to both gather information and to use that information to determine if project

modifications are necessary to provide mitigation and resource protection.






As for pinniped monitoring, harbor porpoise observations will be conducted with either a tripod

mounted theodolite or reticle binoculars. Simultaneous high-definition video will be obtained of

groups, after the techniques described by DeNardo et al. (2001).

The Adaptable Monitoring Package (AMP) on each turbine will be equipped with a pair of C-

POD (www.chelonia.co.uk) click detectors. These will be recovered and redeployed every 3-6

months as part of the standard maintenance cycle. Redundancy is indicated from pre-installation

experience with these instruments. If a cabled C-POD (provisionally, the “F-POD”) becomes

available of the lifetime of the project, it could be integrated into a spare port on the AMP to

enable real-time click detections.

Collection Procedure

Continuous focal animal or focal group sampling will be conducted using the theodolite-video

methodology (described in DeNardo et al., 2001) or a modified recticle binocular-video

methodology. In either case, an animal, or group of animals, is tracked through the study area.

Initial detection of harbor porpoise will be through the methodical scans undertaken for pinniped

monitoring (§5.1). Observational data will, initially, be collected during pinniped surveys using

the observational sampling procedure shown in Figure 9 by a single survey team. If significant

survey overlap is found to exist (i.e., both pinnipeds and harbor porpoise are commonly within

the study area and breaking off for harbor porpoise focal follows leads to a low number of

complete pinniped scans), then, with the concurrence of the MARC, the pinniped and harbor

porpoise observations will be handled by separate survey teams.

Focal follows of harbor porpoise will be discontinued if killer whales are detected (analogous to

breaking off pinniped scans if harbor porpoise detected).

C-PODs on the turbines will be configured to limit detections of bedload transport (i.e., high pass

filter set to 40 kHz). Pre- and post-deployment calibrations of C-POD sensitivity will be

undertaken.

5.2.3 Data Analysis

Porpoise visual data: Using the theodolite/reticle binocular location data, the point of closest

approach (POCA) and directionality (i.e., approach towards the turbines outside of zone of

audibility and movement while inside zone of audibility) can be tested against the signal excess

for turbine sound. Focal follows that are determined to begin inside the zone of audibility will

not be included in analyses. Given that harbor porpoise were observed in 63% of the observation

days during the pre-installation study, sufficient sample sizes to achieve useful statistical power

should be achievable. If theodolite/reticule binocular accuracy for harbor porpoise observations

is lower than expected, it may be necessary to convert locations to grid cells and analyze with

GAM/GEE, as per the pinniped analyses.




C-POD Detection Range: After Kyhn et al. (2012) porpoise visual data will be compared against

click train information in order to assess C-POD detection range and develop empirical

calibrations to predict absolute abundance on the basis of detections.

Changes to Porpoise Echolocation Activity: Comparisons will be made to pre-installation

information (3+ years), in order to determine if statistically significant differences in

echolocation activity, or trends in echolocation activity (such as night/day or seasonal variations,

as determined by a Generalized Linear Model) have changed significantly as a consequence of

turbine operation.

Instances of Landmark Activity: Using Chelonia, Ltd. software, the number and frequency of

“landmark” click sequences (suggestive of harbor porpoise echolocating at the turbines and,

therefore, awareness of their presence) will be determined and compared to number and

frequency of pre-installation “landmark” click sequences associated with Sea Spider

instrumentation packages. If a sufficient number of landmark events are observed, these will be

stratified by turbine source level.


A preliminary, oral report will be made to the MARC within 60 days of turbine installation and

quarterly thereafter describing number of harbor porpoises observed within the study area by

shoreline observers and the device operating state during these observations. A final written and

oral report will be made to the MARC within 120 days of survey completion (one calendar year

of operation) describing the observations, statistical modeling approach, and results.




concurrence of the MARC.

If a statistically significant effect on echolocation activity is observed due to turbine operation,

the MARC will determine whether a gradient study could be used to determine the spatial extent

of this change. If the C-POD information suggests that harbor porpoise echolocation is

unchanged by the presence/operation of the turbines, then data collection with C-PODs will

continue over the lifetime of the project, but without analysis.

If harbor porpoise and pinniped scans overlap to the point that harbor porpoise focal follows are

significantly reducing the effectiveness of pinniped observations, then, with the consent of the

MARC, a separate observational team will be tasked for pinniped and harbor porpoise

observations. In conjunction with the MARC and with NMFS approval, as provided in section

6.0, this information will be used to inform project modifications, where necessary, to provide

mitigation and resource protection.




5.3 Killer Whale Response to Turbine Presence

5.3.1 Objective

Killer whales are an iconic species in Puget Sound. The National Marine Fisheries Services

designates Southern Resident killer whales as endangered and the State of Washington extends

this designation to all killer whales (Southern Residents and transients). In recognition of this,

the Marine Mammal Monitoring and Mitigation Plan allocates a higher intensity of effort to

observing their behavioral response to the turbines than other marine mammals. Information

about how killer whales interact with tidal turbines must be established before larger-scale or

longer-term tidal energy installations could be considered in Admiralty Inlet. Unlike pinniped

and harbor porpoise monitoring, monitoring of killer whales will continue throughout the project

lifetime and utilize shore-line observers, localizing hydrophones, and the near-turbine monitoring

system. These tools will be utilized in a rapid-response mode when killer whales (Southern

Resident or transient) are transiting through Admiralty Inlet. The objectives of gathering this

information are both to learn more about orca interaction with the turbines and to prevent harm

to orcas through mitigation based on this information.



Observations will utilize the same equipment and procedure as described for harbor porpoise

(§5.2). Reticule binoculars are more likely to be used in concert with high definition video than

theodolites because of the logistical challenges of mobilizing an observer trained in the use of a

theodolite in a rapid-response mode. Observations obtained during pinniped/harbor porpoise

monitoring may be more likely to utilize a theodolite.

Shoreline observations will be complimented by two monitoring systems located on the turbine

foundation: a passive acoustic array and the near-turbine monitoring system (described in the

Near-turbine Monitoring and Mitigation Plan). The passive acoustic array is intended to localize

marine mammal vocalizations and will consist of four hydrophones installed on one of the

turbine foundations, as shown conceptually in Figure 10. The hydrophones will have a functional

frequency range up to at least 200 kHz in order to detect killer whale vocalizations. Unlike the

hydrophone described in the Acoustic Monitoring and Mitigation Plan, these hydrophones will

not be shielded from flow noise, as the frequencies associated with killer whale vocalizations do

not overlap with frequencies associated with flow noise. The localizing array is not part of the

Adaptable Monitoring Package (AMP) and, consequently, cannot be serviced over the lifetime of

the project. Should the array fail, its function could be replicated by a vertical line array deployed

from a drifting vessel in a rapid response mode.




Figure 10 – Passive acoustic array on OpenHydro turbine. Hydrophone configuration is preliminary.

Killer whale monitoring will also include an update to the hydrophone at the Port Townsend

Marine Science Center, in order to increase the likelihood of effective rapid response and to

support observer networks in Puget Sound.

Collection Procedure

Upon auto-detection of killer whale calls on the hydrophones on the turbine, the hydrophone at

the Port Townsend Marine Science Center, or a sightings report via the enhanced Orca Network

sightings network , a land based observing team will respond to Admiralty Head and commence

data collection. Of the 14 daytime transits of Southern Resident killer whales through Admiralty

Inlet during the 7 month pre-installation study, the land response team was able to collect data on

10 transits (71%).

Shoreline observers will select the most appropriate focal group of killer whales (the ones that

appear most likely to approach study area). If several groups are present, observers will focus on

the group likely to pass closest to the turbines and maintain the focal follow even if, during the

transit, another group passes closer to the turbines. Using the reticle binoculars/theodolite and

video, the location, time of surfacing, behavior state, and surface active behaviors (SAB) of the

focal group will be recorded. Depending upon initial results, observers may wish to prioritize

males for focal follows, due to ease of identification and tracking. Any such changes to the

observational protocol will be made with the agreement of the MARC.




Rapid response will be initiated for any killer whale siting, either Southern Residents or

transients.

Data from the hydrophone array will be streamed back to shore and archived for subsequent

analysis of killer whale location, call rate, and echolocation click rate. Analysis will be

conducted for all transits, even those for which a rapid response team is unable to mobilize to

Admiralty Head to conduct shoreline observations. Transient killer whales vocalize infrequently,

since their vocalizations are audible to their prey.

The near-turbine monitoring system can be used to evaluate close-range interactions. The system

is capable of operating at high frame rate (i.e., 10 frames per second) for extended periods of

time. In consultation with the MARC, a sampling strategy for the camera system will be

developed that minimizes the risk of confounding impacts (startle response, attraction, or

avoidance) as a consequence of operating the system.

During all observations, vessel traffic will be monitored using the AIS on Admiralty Head,

current velocity will be monitored using the Doppler profilers on the turbines, and turbine power

generation state will be monitored by the SCADA.

5.3.3 Data Analysis

Unlike harbor porpoise or pinnipeds, the number of killer transits will not be large enough to

employ a grid-based GAM/GEE analytical approach, as power to detect change will be too low.

In order to test the hypotheses of attraction/avoidance or behavioral change, the following

metrics will be used:

Directionality of transit

Surfacing interval

Behavior state

Surface active behavior (SAB)

Click rate

Call rate.

These metrics will be stratified by signal excess of turbine sound within the zone of audibility.

Focal follows that are determined to begin inside the zone of audibility will not be included in

analyses.

Given the small number of transient killer whale transits through Admiralty Inlet each year,

statistical power to detect effects on transients will be too low to treat them as a distinct

functional group. Consequently, two functional groups will be established for analysis and

reporting. The first will be a mid-frequency cetacean group consisting of Southern Resident and

transient killer whales. Analyses for this group will involve only non-vocal metrics (i.e., exclude

click rate and call rate) due to differential vocalization between the two species. The second

functional group will be Southern Resident killer whales. Analyses for this group will include all

metrics described above.

All tests will use repeated measures general linear model designs (Neter et al., 1996; Deecke,

2006) to control for other known sources of variance and to increase the power of the tests.




Although the point of closest approach (POCA) could be used as a dependent variable,

preliminary power analyses for POCA which would involve a control of turbine non-operating

period (and therefore not a repeated measures design), indicate a sample size of ~29 transits for

the coarsest possible grouping (turbine operational, non-operational) would be needed to detect a

30% effect size. In other words, each transit yields one observation of POCA, but multiple

observations of the behavioral parameters outlined above. Sample size requirements would

further increase if, as expected, observations need to be stratified by power generation (and, by

extension, extent/intensity of acoustic stressor). Therefore, POCA is not considered a worthwhile

test metric for detecting turbine acoustic impact for killer whales.

For all other metrics, initial power analyses indicate the need for a sample size of ~16 transits to

detect a 30% change (Appendix 3). This is more achievable, but will ultimately depend on the

number of daytime transits of killer whales during the turbine deployment.

The results of near-turbine monitoring will be used to evaluate whether prey was likely

aggregated near the turbine during transit (attractive effect). Analysis of vocalizations detected

by the hydrophone array will provide probable location (x,y,z) and activity state for individuals

(implied from call and click rates).


A preliminary, oral report will be made to the MARC within 7 days of each transit describing

number of killer whales observed within they study area, the device operating state during these

observations, and any notable behavioral changes. A final written and oral report will be

presented to the MARC with 120 days of the end of each calendar year of operation.

If survey approach described here does not provide useful information about killer whale

interactions with turbine, the MARC may modify the survey methodology.




concurrence of the MARC. In conjunction with the MARC and with NMFS approval, as

provided in section 6.0, this information will be used to inform project modifications, where

necessary, to provide mitigation and resource protection.

6.0 APPROACH TO ADAPTIVE MANAGEMENT AND MITIGATION

In implementing this Plan, the District will consult with the MARC as appropriate on the

technical issues described above and data interpretation associated with the monitoring. Such

consultation will include consideration of results from monitoring efforts and subsequent

adjustments to monitoring methods. All decisions will be based on analyses with a significance

level of 0.05. In particular, the District will adopt the triggers and subsequent actions described

below.

The District will follow the procedures described in the Adaptive Management Framework when

conferring with the MARC on implementation of the Acoustic Monitoring and Mitigation Plan

and considering how to address the results of the monitoring.




Adaptive Management and Mitigation Trigger 1: Based on the field test of observational

protocols (e.g., scan sampling) in the fall of 2012, an optimized survey area (likely a circle with a

radius of 500-1000 m centered on the turbines) and scan pattern will be submitted to the MARC

for review and approval. The study area extent will balance the need for observations to be

obtained both outside and inside the zone of audibility and the need for well-resolved

observations of marine mammals in time and space. Similar changes to the monitoring protocols

may be required for the seasonal sampling allocation (i.e., higher effort in the winter versus

summer) and selection of focal groups for killer whale transits. If the results of these studies

indicate any harm to marine mammals, the District will develop modifications to the project

and/or this Plan in consultation with the MARC, will obtain NMFS’ approval for any specific

mitigation measures.

Adaptive Management and Mitigation Trigger 2: If the results of the Acoustic Monitoring

and Mitigation Plan indicate that the zone of audibility for turbine sound is greater than indicated

by pre-installation estimates, the size of the study area may be increased to ensure that

observations of marine mammal functional groups are obtained both outside and inside of the

zone of audibility. If the results of these studies indicate any harm to marine mammals, the

District will develop modifications to the project and/or this Plan in consultation with the

MARC, will obtain NMFS’ approval for any specific mitigation measures.

Adaptive Management and Mitigation Trigger 3: If porpoise presence or echolocation

activity (defined by median detection positive minutes per day – DPM/day) shows a statistically

significant change during the first calendar year of operation relative to annual median DPM/day

from baseline observations at the 5% significance level, the District will consult with the MARC

and determine if the change is biologically significant and if modification of the Project or

Monitoring and Mitigation Plan is necessary. Upon approval of revisions to the Plan by the

MARC, the District shall file the revised Plan with the Commission. Upon Commission

approval, the District shall implement the revised Plan. If the results of these studies indicate any

harm to marine mammals, the District will develop modifications to the project in consultation

with the MARC, will obtain NMFS’ approval for any specific mitigation measures.

Adaptive Management and Mitigation Trigger 4: If shoreline observers note a strong

avoidance response (defined as consistent and rapid movement away from the study area) for any

marine mammal functional group, the District will consult with the MARC and determine if

modification of the Project or Monitoring and Mitigation Plan is necessary. Upon approval of

revisions to the Plan by the MARC the District shall implement the revised Plan.

Adaptive Management and Mitigation Trigger 5: If a killer whale has been found to be

injured (lacerations or discoloration to extremities) in the Salish Sea within a week of a known

transit through Admiralty Inlet, the District will consult with the MARC to discuss whether the

injury could have been caused by the Project. An independent experienced veterinarian will be

part of the MARC for these discussions. If the MARC determines that the injury was caused by

the Project, the District will immediately cease operation of the Project and will not resume

operations until NMFS approves the resumption of operations. The MARC will evaluate whether

additional protective measures, if any, can be implemented to protect killer whales. Upon the

request of the MARC, the District will revise this Plan to implement additional measures to

ensure effective protection of killer whales within the vicinity of a rotating hydrokinetic turbine.




Upon approval of revisions to the Plan by the MARC and NMFS, the District shall implement

the revised Plan.

Adaptive Management and Mitigation Trigger 6: If behavioral responses to the presence of

the turbine by mid-frequency cetaceans (Southern Resident and transient killer whales) within

the survey area are reported, the District will convene a meeting of the MARC to evaluate

whether modifications to the Plan or Project operations are necessary. Upon approval of

revisions to the Plan by NMFS, the District shall implement the revised Plan. If the results of

these studies indicate any harm to marine mammals, the District will develop modifications to

the project in consultation with the MARC, will obtain NMFS’ approval for any specific

mitigation measures.

Adaptive Management and Mitigation Trigger 7: Pinnipeds are food motivated. If the Near-

turbine Monitoring and Mitigation Plan indicates that prey is aggregating around the turbines

after the first calendar year of pinniped observations is complete (and such aggregations did not

occur during the first calendar year), a short-term pinniped study (e.g., 2+ weeks observations)

will be conducted to evaluate whether prey aggregations are affecting behavior in the vicinity of

the Project. The specific study scope will be developed in consultation with the MARC. If the

results of these studies indicate any harm to marine mammals, the District will develop

modifications to the project in consultation with the MARC, will obtain NMFS’ approval for any

specific mitigation measures.

Adaptive Management and Mitigation Trigger 8: If harbor porpoise and pinniped scans

overlap to the point that harbor porpoise focal follows are significantly reducing the

effectiveness of pinniped observations, then, with the consent of the MARC, a separate

observational team will be tasked for pinniped and harbor porpoise observations.

By June 30 of each year, the District will develop and file an annual report to FERC fully

describing its implementation of the Plan during the previous calendar year and a list of the

proposed activities during the current calendar year. The MARC will have at least 30 days to

review and comment on a draft report prior to the District finalizing and filing the report with

FERC. The annual report will provide the following:

A summary of the monitoring results;

A summary of any issues or concerns identified by members of the MARC during the

year regarding implementation of the Plan;

A list of any changes to the Plan and/or project operations proposed by consensus of the

MARC during the year; and

A list of Plan activities planned for the current year.

As described in the monitoring plan details, the MARC will also receive specific reports on each

plan on the following schedule:

Pinniped monitoring (§5.1): Preliminary, oral report on sightings within first 60 days of

turbine operation and quarterly, thereafter. Final report on pinniped response to turbine

operation within 120 days of the end of the first calendar year of operation.




Harbor porpoise monitoring (§5.2): Preliminary, oral report on sightings within first 60

days of turbine operation and quarterly, thereafter. Final report on harbor porpoise

response to turbine operation within 120 days of the end of the first calendar year of

operation.

Killer whale monitoring (§5.3): Preliminary, oral report to the MARC within 7 days of

each transit. Final report on killer whale activity and response to turbine operation within

120 days of each calendar year of operation.

7.0 REFERENCES

Basset, C., B. Polagye, M. Holt, and J. Thomson (in press) A vessel noise budget for Admiralty

Inlet, Puget Sound, WA (USA), J. Acous. Soc. Am.

Basset, C., J. Thomson, and B. Polagye (submitted) Contribution of bedload transport to ambient

noise in a high-energy environment, Submitted to J. Geo. Res.

Bigg, M. (1982) An assessment of killer whale (Orcinus orca) stocks off Vancouver Island,

British Columbia. Report of the International Whaling Commission 32:655-666.

Carlson, T.J., J.L. Elster, M.E. Jones, B.E. Watson, A.E. Copping, M. Watkins, R. Jepsen, and K.

Metzinger (2012) Assessment of strike of adult killer whales by an OpenHydro tidal turbine

blade, Pacific Northwest National Laboratory technical report, PNNL-21177

Calambokidis, J. and Baird, R. (1994) Status of marine mammals in the Strait of Georgia, Puget

Sound and the Juan de Fucca Strait and Potential human impacts. Symposium on the

Marine Environment. January 13 and 14, 1994.

Collar, C., J. Spahr, B. Polagye, J. Thomson, C. Bassett, J. Graber, R. Cavagnaro, J. Talbert, A.

deKlerk, A. Reay-Ellers, D. Tollit, J. Wood, A. Copping, T. Carlson, and M. Halvorsen

(2012) Study of the acoustic effects of hydrokinetic tidal turbines in Admiralty Inlet, Puget

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Attachment 1

Carlson, T.J., J.L. Elster, M.E. Jones, B.E. Watson, A.E. Copping, M. Watkins, R. Jepsen, and K.

Metzinger (2012) Assessment of strike of adult killer whales by an OpenHydro tidal turbine

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Attachment 2

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case study for Admiralty Inlet, Puget Sound, Washington (USA)”

Attachment 3

Power Analysis for Ability to Detect Changes related to Southern Resident Killer Whales

Power Analysis for Ability to Detect Changes related to Southern Resident Killer Whales

Introduction

The power of a statistical test is a measure of the likelihood that a finding of no significant difference is

actually true. This metric is important for monitoring studies, as there needs to be confidence in a finding

of no impact. As power increases, confidence in the finding of no impact increases. Power is calculated as

1 – β where β is the probability of committing a type II error (the false negative rate). Given the type I

error rate (α or the false positive rate) and effect size, an a priori calculation of sample size for various

levels of power can be calculated. This analysis aims to do that for the various metrics proposed in the

Marine Mammal Monitoring and Mitigation Plan to assess changes in killer whale behavior.

Methods

The following monitoring variables have been proposed in the Marine Mammal Monitoring and

Mitigation Plan: Point of Closest Approach (POCA), directionality of transit, surfacing interval, surface

behavior state, surface active behavior (SAB), click rate, and call rate. A power analysis for surface

behavior state was not calculated as this was beyond the capabilities of the software used. G*Power 3.1.3

was used for all power calculations. POCA means were considered to be independent, whereas all other

variables were considered to be matched pairs (repeated measures).

The threshold of change evaluated here is a 30% change in the means of a metric. Power calculations

depend on the type I error probability and the effect size. Type I error rate was set at 0.05. Statistical

effect size (ES) is based on the change in means as well as the standard deviation of that population as

where is the mean of the impact group, is the mean of the control group and s is their standard

deviation. To use plausible means and standard deviations, the literature on Southern Resident killer

whales (SRKW) was surveyed. If that data was not reported for SRKW, then data from studies on

Northern Resident killer whales (NRKW) was used. For studies that reported standard error, this was

multiplied by the square root of the sample size to determine the standard deviation. Table 1 shows the

values used and the resulting effect sizes that were used to calculate power and sample size.

Table 1 - Input variables and studies from which they were taken to calculate effect size.

Study Variable Mean SE N SD

30% change

in mean

Effect

Size Notes

Noren et al. 2009 POCA 131.7 6.5 193 90.30 171.2 0.44 all vessels in 2006

Williams et al.

2002

Directionality

of transit 85 3 16 12.00 110.5 2.13 males only

Williams et al.

2002

Surfacing

interval 42 2 16 8.00 54.6 1.58 males only

Williams et al.

2002 SAB 1.2 0.3 16 1.20 1.6 0.30 males only

Beneze et al. 2011 Click rate 83.9 370 78.10 109.1 0.32 all behaviors

Scurci 2011 Call rate 3.68 58 4.40 4.78 0.25 all behaviors

s

xxES

oa

ax

ox

Results

Power varied by sample size for the different variables with directionality and surfacing interval having

the highest power at low sample sizes and POCA having the lowest power (Figure 1). Table 2 lists

estimated sample sizes needed for low and high levels of power.

Figure 1 - Effect of sample size on power for the six metrics proposed for the monitoring plan (30% change).

Table 2 – Sample sizes needed for high and low power levels.

Variable

Sample size needed

(power=0.2,

alpha=0.05)

Sample size needed

(power=0.8,

alpha=0.05)

POCA 28 166

Directionality of transit 3 4

Surfacing interval 3 6

SAB 16 90

Click rate 15 79

Call rate 22 128

Conclusions

Given the large difference in effect size for each of these metrics; it is not surprising that power varies so

much for a given sample size. This variance in effect size is largely dependent on the standard deviation

used to calculate effect size. Given that the standard deviations used for these calculations were reported

for studies in other areas on this and other populations of killer whales, these results should be interpreted

more as upper and lower bounds of potential power for tests used in the Marine Mammal Monitoring and

Mitigation Plan. POCA will have the lowest power since it will be tested with independent means. All

other variables will use a repeated measures test and will therefore have higher power. How much power

will depend largely on their standard deviations.

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

0 50 100 150 200

Po

we

r

Sample Size

POCA

Directionality

Surfacing interval

SAB

Click rate

Call rate

References

Beneze, E. L., Wood, J. D., Veirs, S., & Veirs, V. (2011). Are click rates in killer whales an indicator of

group behavior and foraging hotspots? Journal of the Acoustical Society of America, 129(4), 2607.

Noren, D. P., Johnson, A., Rehder, D., & Larson, A. (2009) Close approaches by vessels elicit surface

active behaviors by southern resident killer whales. Endangered Species Research, 8, 179-192.

Scurci, K. (2011) Testing the motivation-structural rules hypothesis in Southern Resident killer whales

(Oricnus orca). Senior Thesis. College of the Atlantic.

Williams, R., Trites, A. W., & Bain, D. E. (2002) Behavioural responses of killer whales (Orcinus orca)

to whale-watching boats: opportunistic observations and experimental approaches. Journal of

Zoology, 256(2), 255–270.

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