Evaluation of Coho and Steelhead Production in the San Geronimo Valley Headwaters of the Lagunitas Creek Watershed, 2006-2008

Prepared by

Christopher Pincetich, Ph.D., SPAWN Watershed Biologist Todd Steiner, M.S., SPAWN Executive Director Paola Bouley, M.S., SPAWN Conservation Program Director

Ssssssssssssssssss Salmon Protection Salmon Protection And Watershed Network And Watershed PO Box 370 • Forest Knolls, CA 94933 Network Ph. 415.663.8590 • Fax 415.663.9534 PO Box 400 • Forest www.SpawnUSA.org Knolls, CA 94933 i Salmon Protection and Watershed Network (SPAWN)

Evaluation of Coho and Steelhead Production in the San Geronimo Valley Headwaters of the Lagunitas Creek Watershed, 2006-2008

Table of Contents

Abstract…………………………………………………………………………………………………...…1

Introduction……………………………………………………………….…………………….…………...1 Lagunitas Coho………………………………………….…………………………..……...…...1 Lagunitas Steelhead………………………………………….…………………….….…….....2 San Geronimo Valley Headwaters………………………………………….….………….....2 Salmon Protection and Watershed Network (SPAWN)………………...…..…………....2 Methods……………………………………………………………………………………………..…...…4 Smolt Trap Design and Location ………………………………………………...……...….4 Daily Monitoring………………………………………………………………………..…..……5 Data Analyses………………………………………………………………………………...…6 Fulton Condition Factor……………………………………………………………..……..…..6 Results……………………………………………………………………………………..……...….….…6 Coho Salmon………………………………………………………………………..…..…….…7 Steelhead……………………………………..……………………………………..…..………10 Other Aquatic Organisms ……………………………………..……………………..…...…14 Discussion……………………………………………………………………………………….……...…15 Acknowledgements…………………………………………………………………………….…………17 References……………………………………………………………………………………………...…18

List of Tables

Table 1. Summary of coho smolt population estimates from San Geronimo Valley (SGV) and total Lagunitas Creek Watershed (LCW)…………………………….………………………...………...……6

Table 2. Summary of coho smolt measurements from the San Geronimo Creek monitoring station………………………………………………………………………………………………………..7

Table 3. Table 2. Summary of steelhead smolt population estimates from San Geronimo Valley (SGV) and total Lagunitas Creek Watershed (LCW). ………………………………..…..……..……11

Table 4. Summary of measurements from San Geronimo Creek steelhead smolts with smoltification code 4. …………………………..…………………..…………………………...….……11

Table 5. Summary of measurements from San Geronimo Creek steelhead juveniles with smoltification codes 2-3. ……………..…………………………………………….……………..……..11

Table 6. Summary counts of non-salmonid species recovered in smolt traps……………………..14

Table 7. Summary of average coho smolt fork lengths from SPAWN (SGV), MMWD (Lagunitas), and NPS (Olema and Redwood Creeks) ……………………………………………………………...16

ii Salmon Protection and Watershed Network (SPAWN)

Table 8. Summary of new coho smolt physiology from Lagunitas Creek Watershed (LCW; MMWD data). ……………………………………………………………………………………………….……...16

Table 9. Summary of marked, recaptured SGV coho smolt physiology as measured at downstream LCW monitoring station. ……………………………………………………………..…...16

Table 10. Summary of marked, recaptured LCW coho smolt physiology as measured at downstream LCW monitoring station. ……………………………………………………………..…...16

List of Figures

Figure 1. The Lagunitas Creek watershed is located north of San Francisco Bay in Marin County, California, and originates near the top of Mount Tamalpias and flows north to Tomales Bay. The San Geronimo Creek watershed is the upper, un-dammed headwater tributary that joins Lagunitas Creek 7.2 km downstream from its origins on White’s Hill…...……………………………3

Figure 2. The San Geronimo Valley sub-watershed contains twelve main tributaries that currently support coho salmon or steelhead. The location of the three outmigrant smolt monitoring stations are shown along San Geronimo, Arroyo, and Larsen Creeks.…………………………………....…4

Figure 3. The smolt traps were constructed as a combination fyke net/pipe trap design intended for larger creeks (A). Smolts were measured (B) and weighed (C) while immersed in cold creek water to minimize handling stress. …………………………………………………………………….…5

Figure 4. Outmigrant coho smolt captures, capture probability, and population estimates from 2006 monitoring in San Geronimo Creek………………………………………………………….….…7

Figure 5. Salmonid measurements from 2006 San Geronimo Creek monitoring of fork length and wet weight plotted for coho smolts………………………………………………………………………..8

Figure 6. Outmigrant coho smolt captures, capture probability, and population estimates from 2007 monitoring in San Geronimo Creek……………………………………………...……….…….….8

Figure 7. Salmonid measurements from 2007 San Geronimo Creek monitoring of fork length and wet weight plotted for coho smolts ……………………………………………………………………….9

Figure 8. Outmigrant coho smolt captures, capture probability, and population estimates from 2008 monitoring in San Geronimo Creek……………………………………………………….....…….9

Figure 9. Coho smolt weekly average length and abundance in San Geronimo Creek in 2008…10

Figure 10. Salmonid measurements from 2008 San Geronimo Creek monitoring of fork length and wet weight plotted for coho smolts ………………………………………………………..………10

Figure 11. Outmigrant steelhead smolt captures, capture probability, and population estimates from 2006 monitoring in San Geronimo Creek……………………………………………….…..……11

Figure 12. Steelhead smolt and parr measurements of fork length vs. wet weight plotted from 2006 San Geronimo Creek monitoring…………………………..……………………………….….…12

Figure 13. Outmigrant steelhead smolt captures, capture probability, and population estimates from 2007 monitoring in San Geronimo Creek…………………………………….………….….…...12

iii Salmon Protection and Watershed Network (SPAWN)

Figure 14. Steelhead smolt and parr measurements of fork length vs. wet weight plotted from 2007 San Geronimo Creek monitoring…………………………..…………………………..…………13

Figure 15. Outmigrant steelhead smolt captures, capture probability, and population estimates from 2008 monitoring in San Geronimo Creek………………………………………………..……….13

Figure 16. Steelhead smolt weekly average length and abundance in San Geronimo Creek in 2008…………………………………………………………………………………………………..…....14

Figure 17. Steelhead smolt and parr measurements of fork length vs. wet weight plotted from 2008 San Geronimo Creek monitoring…………………………..…………………………..…………14

iv Abstract

The San Geronimo Valley (SGV) sub-watershed is a 10 square-mile headwaters region in the Lagunitas Creek Watershed (LCW) of Marin County, California. The LCW supports the largest documented wild population of endangered Central Coast ESU coho salmon and is also home to the 2nd largest population of threatened CCC ESU steelhead. Smolt production of coho salmon and steelhead in the SGV was determined through outmigrant monitoring during the spring months of 2006 - 2008 by the Salmon Protection and Watershed Network (SPAWN). SPAWN biologists made daily observations and measurements at three fyke-net fish traps and used a consistent mark and recapture strategy to estimate the number of coho salmon or steelhead smolts migrating toward the ocean. These headwaters monitoring efforts were done in coordination with efforts downstream on lower Lagunitas Creek at a trap operated by the Marin Municipal Water District (MMWD). Coho smolt captures and population estimates were larger each year than those for steelhead in the SGV, and average coho smolt fork length declined each year of monitoring. In 2008, average weekly fork length measurements were compared and there was no significant difference in smolt size during the individual weeks of the outmigration period for either coho or steelhead. Overall, average coho smolt size in the SGV was smaller than that observed at the downstream Lagunitas trap each year, but analyses of SGV smolts recaptured downstream revealed that the average size of these fish had increased during downstream migration to very near the average recaptured downstream smolts. The smolt population in both SGV and LCW was lowest in 2007, which correlates to low juveniles population estimates in the summer of 2006 caused by the highest flows recorded since 1982 during the new year eve’s storm of 2005/06. For the period of monitoring by both SPAWN and MMWD from 2006-2008, the SGV, which is less than 9% of the total LCW, supported 24%- 53% of the total LCW estimated coho smolt population, validating the importance of continued habitat conservation, restoration and monitoring efforts in this area.

Introduction

The Lagunitas Creek watershed (LCW) of Marin County supports the largest-remaining documented wild population of endangered Central Coast coho salmon (Oncorhynchus kisutch) in California (Moyle et al., 2008). The Central California Coast Evolutionarily Significant Unit (ESU) of coho salmon has been listed as endangered in the State of California and under the U.S. Endangered Species Act (ESA) since 2005. The SGV also supports a population of Central California Coast ESU steelhead (Oncorhynchus mykiss) that has been listed at threatened under the ESA since 2006.

Lagunitas Coho The LCW occupies 281.85 km2 (69,646 acres) in Marin County Ca, and contains 56.32km (35 miles) of endangered coho salmon coho bearing streams and 59.55km (37 miles) of threatened steelhead streams (NOAA SWFS, 2008), including Lagunitas Creek, Devil’s Gulch Creek, and San Geronimo Creek and its tributaries. Coho salmon essentially have a fixed three-year life cycle, and for coho, a separate year class is created every three years and can be considered essentially a separate population because there is little mixing among year class lineages. The exception can be the occurrence of “jacks” that return as 2-year old males in limited numbers and when juveniles hold-over for a second year in their natal stream. Unlike most Pacific salmon that migrate to the ocean the same year they emerge as fry, juvenile coho salmon emerge from redds in late winter to early spring and spend over one year in the stream before undergoing a physiological and morphological smoltification process and migrating to the ocean in the spring of their second year of life. During smoltification, their scales slough and their vertical parr marks along the lateral line fade and become a uniform silver color, their length increases in proportion to their girth, and they begin physiological adaptations to prepare them for life in seawater. They spend about 1.5 years in the ocean and return to spawn in the late fall to early winter three years from when they were spawned.

Smolt outmigration monitoring, in conjunction with other life stage monitoring activities, can assist in characterizing the geographical and seasonal distribution of productivity for salmonids, and is a valuable resource for directing long-term management and restoration actions for their freshwater 1 Salmon Protection and Watershed Network (SPAWN) habitat. Data collected through smolt trapping also has direct management utility, as it can lead to a better understanding of the environmental factors, and their timing, that result in cessation of downstream smolt movement, which may be used to determine instream restoration windows that would not impair migration of smolts (NPS SOP, 2005).

Although our smolt monitoring is focused on salmonid smolts migrating to the ocean, it also provides additional presence, relative abundance and size measurement data for other native and non-native aquatic species captured in our traps.

Lagunitas Steelhead Steelhead are the anadromous form of rainbow trout and have a much more flexible life history when compared to coho salmon. Adult steelhead typically spawn later and fry emerge from gravel redds later in the year than coho salmon, and can spend anywhere from 1-2 years as juvenile parr in the streams before undergoing the physiological and morphological maturation into a smolt and migrating to the ocean. They can spend 0.5-2 years in the ocean before returning to spawn in the mid to late winter. Steelhead are known to be iteroparous, meaning they can make several spawning trips between fresh and salt water in their life span. Adult steelhead in the LCW typically return to spawn mid to late winter and through the spring and have been observed to reside in deep pools throughout the watershed for many months, including summers during low water years such as 2007 and 2008.

The San Geronimo Valley Headwaters The 24.26 km2 (5,995 acre) SGV watershed drains to San Geronimo Creek which flows 7.2 km (4.5 mi) from its source on White’s Hill to its confluence with Lagunitas Creek, and contains twelve tributaries, including 1st through 3rd order sub-basins ranging in size from 0.38 to 3.8 km2 (293.9 to 939.0 acres; Figures 1&2; SWS, 2009). The five major tributaries to San Geronimo Creek are Woodacre, Willis Evans Canyon, Larsen, Montezuma, and the Arroyo/El Cerrito/Barranca complex. The SGV is listed by the National Marine Fisheries Service in their draft “Coho Recovery Plan” as one of their top-ten high-priority “core” conservation area across the entire range for CCC ESU coho salmon (NMFS pers. comm., 2009). The LCW as a whole received the highest possible priority listing (a 5 out of 5) for directing recovery efforts for coho salmon by the California Department of Fish and Game (CA DFG) in the “Recovery Strategy for California Coho Salmon” document (CA DFG, 2004). The SGV is extremely important habitat for coho salmon, comprising less than 9% of the total area of the LCW and in recent years supporting up to 40% of LCW coho spawning and 39% of smolt production.

The SGV is also the location of West Marin’s largest residential human population. Of the total watershed area, 58% is privately owned with 40% of these private parcels occurring directly within 100-ft of a stream, encroaching on critical riparian and floodplain habitat. Significant human impacts occur in this area impacting not only San Geronimo Creek and its tributaries, but also reaches of Lagunitas Creek downstream of this area in State and Federal lands. Current impacts of high concern include loss of riparian habitat to past land-use and more recent development, excessive fine sedimentation due to runoff from poorly maintained roads and development, a paucity of winter flow-refuge and summer rearing habitats, contamination of surface waters from leaking septic systems and roads, and migration barriers such of dams, and culverts that block off >50% of historical spawning habitat. These impacts currently threaten the viability of the ecosystem and the systems ability to support coho. Coho recovery guidance provided by CA DFG in 2004 for the LCW and SGV state “work with private landowners to encourage biotechnical bank stabilization, riparian protections, woody debris retention, continue public outreach and education for private landowners, residents, commercial, public utility and county workers regarding best management practices to control erosion“ and published guidance from California native fish expert Dr. Peter Moyle state “housing developments along San Geronimo Creek must be constructed in such as way as to do no damage to the creek or to increase its sediment flow into Lagunitas Creek” (Moyle et al., 2008).

Salmon Protection and Watershed Network (SPAWN) Background SPAWN is a community-based grassroots non-profit that was formed in 1996 and has been monitoring summer habitat to relocate salmonids fry from drying pools since 1999, monitoring spawning on tributaries in the SGV since 2001, and monitoring smolt outmigration from the SGV since 2006. Working with private landowners to protect and restore private parcels is of the 2 Salmon Protection and Watershed Network (SPAWN) highest priority for SPAWN and is strongly supported by partner agencies in the watershed such as the Ca Department of Fish and Game, the Regional Water Quality Control Board, National Marine Fisheries Service, Marin Resources Conservation District, National Park Service, and Marin Municipal Water District. SPAWN has completed habitat restoration projects on dozens of private parcels along the riparian in the SGV, including the third-largest landowner the San Geronimo Golf Course, and maintains a volunteer-run Native Plant Nursery comprised of organically raised plants grown from locally collected native seeds and cuttings collected within the SGV and LCW to supply restoration projects with plants. SPAWN community watershed stewardship education activities include an annual Creek Naturalist Training Program, leading hundreds of visitors on Creekwalks to see spawning salmon each year, a “Headwaters-to-the- Sea” NOAA-supported teacher training institute, seminar series featuring local watershed experts, and providing general coho salmon and watershed stewardship principles education at volunteer activities that take place weekly throughout the year.

3 Salmon Protection and Watershed Network (SPAWN)

Methods

Smolt production of coho salmon and steelhead in the San Geronimo Valley was determined during the period of March through June of 2006 – 2008, with daily monitoring of traps led by SPAWN biologists and assisted by trained volunteers. Outmigration smolt surveys were performed in coordination with efforts across the larger Lagunitas Creek watershed by the Marin Municipal Water District (MMWD), Stillwater Sciences (SWS), and Point Reyes National Seashore, and followed the guidance of draft California Department of Fish and Game protocols (Duffy, 2005). SPAWN’s smolt monitoring project is performed under NOAA Fisheries Authorizations and Permits for Protected Species ESA Section 10(a)(1)(A) permit (Pacific fish), Permit #1162 modification 3 scientific research and enhancement issued in 2005 and California Dept of Fish and Game Scientific Collection Permits.

Smolt Trap Design and Location Due to occurrences of high flows on San Geronimo Creek, a combination fyke net/pipe design trap (Gale 2000) intended for larger creeks was used (Figure 3). The primary pipe/fyke net trap was located in San Geronimo Creek ~500 meters upstream of the confluence of San Geronimo Creek and Lagunitas Creek and 10.8 km (6.7 miles) upstream from the migrant trap operated by MMWD. The study area consisted of a wide, cobble and gravel glide with a low gradient and depth of 0.2-1.1 m. The fyke net was supported by identical, 2.5m long wood framed nets that formed a shallow “V” into the primary funnel that spanned approximately 80% of the width of the creek, and sandbags were used to further direct migrating fish into the trap. A 1m area was left open along the shallow bank to allow for upstream migration of adult steelhead, as well as movement of ducks, river otters and other aquatic species. The primary fyke net funnel opening was 1.75m feet wide and 1.75m feet tall, constructed of netting with 3 cm openings for the initial 3 meters and 0.3 cm openings for the final 3 meters of the primary funnel. The funnel terminates in a 20cm diameter plastic pipe that itself terminated into a trap box. The trap box was 0.75m tall, 0.75m wide, and 1.25m long frame covered with 2mm mesh netting, and was divided into two sections by a solid frame containing 2cm metal screen to create an area approximately 25% of the trap box area for fry and other small organisms to remain protected from crawdads and larger

4 Salmon Protection and Watershed Network (SPAWN) fish while in the trap box. In addition, a 1cm mesh panel and zippered opening was added to the back of the trap box to allow fry to pass through the trapping box without being handled when large numbers were being caught that exceeded amount allowed under permit. A continuous light and temperature data-logger (HOBO) was secured in each trap box to record stream temperature and estimate light intensity. Two smaller fyke net traps of similar design were installed in upstream tributaries of the San Geronimo Creek beginning in 2007. These were stationed in Arroyo Creek and Larsen Creek, at 10- 80 meters upstream of their confluence with San Geronimo Creek. The locations of the 3 pipe/fyke net traps are shown in Figure 2.

A B C

Figure 3. The smolt traps were constructed as a combination fyke net/pipe trap design intended for larger creeks (A). Smolts were weighed (B) and measured (C) while immersed in cold creek water to minimize handling stress.

Daily Monitoring Smolt traps were monitored daily early each morning for 11 weeks each year beginning in March and ending in June. Captured fishes were carefully caught with dip-nets and transferred to five- gallon buckets containing freshly collected creek water. Salmon smolts were briefly exposed to carbon dioxide as a sedative. Each fish was identified, fork length measured, weighed, and for juvenile salmonids >85mm in fork length, the degree of smoltification scored on a scale of 1-4 (1=parr, 2=early transitional, 3=late transitional, 4=smolting). Identification was performed with the assistance of “Field Identification of Coastal Juvenile Salmonids” (Pollard et al., 1997). Fork length was determined on all salmon smolts and most other fishes by carefully transferring the dip-netted fish into a measuring device constructed to cradle the fish and retain water to submerge the gills when tilted, and measurements were recorded in millimeters (Figure 3, B). Wet -weight of fish was measured by carefully placing netted fish into a pre-tarred weigh boat containing enough water to submerge the average sized smolt and then weighed to 0.1 gram with a Ohaus Scout Pro 600g field scale (Ohaus, USA; Figure 3, C). Steelhead and coho were considered smolts if they were predominately silver in color, lacking clear parr marks, were loosing scales, had clear fins, and exceeded 85mm fork length. Salmon fry observed in the trap were often numerous and very sensitive to handling stress, and when large numbers of very small fry were observed, these fish were counted and an estimate of length for each 5mm size class was recorded.

The mark and recapture study used to generate population estimates consisted of marking all new coho and steelhead smolts (>85mm fork length, smolt codes 2-4) with a fin clip followed by upstream relocation and release. In coordination with the MMWD downstream monitoring trap, a unique SPAWN marking clip was given to each new smolt each week, and the cycle of clips would repeat after four weeks. Fin clips typically consisted of a 1-2mm right-angle clip from a pair of small, sharp scissors on the rounded edge of the fin. Typical fin clip marks were the upper caudal clip, dorsal and upper caudal clip, or anal and upper caudal clip. When smolts were captured from either Larsen or Arroyo creek by SPAWN, a unique marking clip would be given to attempt the mark and recapture efficiency calculation at these locations and to track smolts migrating downstream from these tributaries to the lower San Geronimo smolt trap. Relocation of marked smolts was performed approximately 30m upstream into a large, deep pool with sufficient

5 Salmon Protection and Watershed Network (SPAWN) cover. Marked smolts that were recaptured were released approximately 20m downstream with other fishes and salmon fry into a large, deep pool with sufficient cover.

Data Analyses Due to the slight differences in smoltification code assignments during different years and the irregularity of timing of steelhead smolts and their resulting smoltification scores, the calculation of measurements for steelhead are presented separately for juveniles with smoltification codes 2-3 and smolts with a smoltification code of 4. Smolt population estimates and capture probability, or trap efficiency, were calculated using Darroch Analysis with Rank-Reduction (DARR 2.0; Bjorkstedt, 2005) analysis and was performed with the assistance of Eric Bjorkstedt at the National Marine Fisheries Service. All smolts marked with a fin-clip were included in the DARR analyses. Coho and steelhead data sets were analyzed separately.

Fulton Condition Factor Fork length was measured and should be the principal factor affecting the weight of most fish species. However, there can be differences in weight between similar length fish of the same species within a particular watershed, within the surrounding region, or due to morphological changes occurring during smoltification. In order to compare length-weight relationships, we applied Fulton Condition Factors (K) to establish comparable indices of condition. Fulton’s condition factor is widely used in fisheries and general fish biology studies, with the intention of describing the “condition”, or relative biomass, of that individual. It is calculated from the relationship between the weight of a fish and its length. The formula for Fulton’s condition factor is: K = W /L3 where K = Fulton’s condition factor, W = the weight of the fish, and L is the length (measured as fork length). A scaling factor was applied to bring the value of K close to 1.

Results

During the first year of monitoring in 2006, a single trap on San Geronimo Creek was operated for 8 weeks from April 21 to June 10. During 2007 and 2008 three traps were operated for 11 weeks, from March 16 to May 31 in 2007 and from March 18 to June 2 in 2008. Due to high stormwater flows, all three smolt traps were removed for 3 days April 24-27, 2007 to prevent harm to fish and damage to equipment. Observations of coho smolts in the San Geronimo Valley from smolt monitoring operations 2006-2008 are presented in Table 1, and steelhead smolt observations are presented in Table 2. During this period, the calculated coho smolt population estimates show the San Geronimo sub-watershed provided suitable rearing habitat to support an average of 39% of the entire coho smolt population in the Lagunitas Creek Watershed and 33% of the steelhead smolt population (Tables 1 and 2).

Table 1. Summary of coho smolt population estimates from the San Geronimo Valley (SGV) and total Lagunitas Creek Watershed (LCW). SGV SGV SGV SGV DARR Coho DARR Total LCW SGV % of Year New Recapture Trap Efficiency Estimate Coho TOTAL 2006 393 130 23% 3,318 (±568) 6,261*(±1,238) 53% 2007 301 144 45% 1,232(±182) 2,776*(±692) 44% 2008 413 168 38% 1,609 (±135) 6,679*(±3,745) 24% Average 369 147 35% 2,053 5,239 39% * Estimate data reported from MMWD/Stillwater Sciences estimate, all other data calculated from DARR 2.0.

6 Salmon Protection and Watershed Network (SPAWN)

Table 2. Summary of new coho smolt measurements from the San Geronimo Creek monitoring station. SGV SGV Coho weight Coho fork length Fulton’s Condition Factor Year (grams±STDEV) (mm±STDEV) (K±STD) 2006 14.8 (±3.6) 110.8 (±8.8) 1.07 (±0.1) 2007 14.1 (±3.8) 110.5 (±9.7) 1.03 (±0.1) 2008 12.5 (±2.6) 106.7 (±7.6) 1.02 (±0.1)

Coho Salmon - 2004/2005 Year-Class Monitoring In 2006, the San Geronimo Creek trap sampled 393 unique coho smolts, and the mark and recapture data was used to calculate a 23% trap capture probability and estimate a population of 3,317 (±568) outmigrating smolts for the year (Table 1).

The peak coho smolt migration in 2006 occurred in weeks 2 and 3, from April 25 through May 8, with 154 and 153 new smolts captured during each week, respectively (Figure 4). The average coho smolt fork length was 110.8 mm (±8.8) and weight was 14.8 grams (±3.6) as presented in Table 2. The Fulton Condition Factor K value was 1.07 (±0.1). The fork length and wet weight measurements were plotted in Figure 5.

There were 20 coho parr observed in San Geronimo Creek in 2006, all <85mm in fork-length.

San Geronimo Creek Coho Smolts 2006 DARR

2500 0.5 DARR Estimate 2250 0.45 New Captures 2000 Capture Probability 0.4

1750 0.35

1500 0.3

1250 0.25

1000 0.2

750 0.15 Capture Probability Number coho smolts

500 0.1

250 0.05

0 0 1 2 3 4 5 6 7 8 Week

Figure 4. Outmigrant coho smolt captures, capture probability, and population estimates from 2006 monitoring in San Geronimo Creek.

7 Salmon Protection and Watershed Network (SPAWN)

San Geronimo Coho Smolt Physiology, 2006

2.8348 35 y = 2E-05x R2 = 0.8782 30

15 Weight (grams) 10

0 80 100 120 140 160 Fork length (mm)

Figure 5. Salmonid measurements from 2006 San Geronimo Creek monitoring of fork length and wet weight plotted for coho smolts.

Coho Salmon - 2005/2006 Year-Class Monitoring The San Geronimo Creek trap captured a total of 301 coho smolts and the mark and recapture data was used to estimate a 45% trap capture efficiency and a year class population estimate of 1,231 (±182.32) individuals in 2007 (Table 1).

The peak coho smolt migration in 2007 occurred in week 8, from May 4-10, with 91 new smolts captured during that week (Figure 6). The average coho smolt fork length was 110.5 mm (±9.7), weight was 14.1 grams (±3.8), and the K value was 1.03 (±0.1) (Table 2). The coho smolt fork length and wet weight measurements are plotted in Figure 7. A total of 8 coho salmon smolts were observed in the Larsen Creek trap, and 4 coho smolts in the Arroyo Creek trap.

There were 2,129 coho fry observed in 2007, with 2,000 in San Geronimo Creek, 126 in Arroyo Creek, and 3 in Larson Creek, all <85mm in fork-length.

San Geronimo Creek Coho Smolts 2007 DARR

350 0.8 DARR Estimate 0.7 300 New Captures 250 Capture Probability 0.6 0.5 200 0.4 150 0.3 100 0.2 50 0.1 Capture Probability Number of coho smolts 0 0 1 2 3 4 5 6 7 8 9 10 11 Week

Figure 6. Outmigrant coho smolt captures, capture probability, and population estimates from 2007 monitoring in San Geronimo Creek.

8 Salmon Protection and Watershed Network (SPAWN)

San Geronimo Coho Smolt Physiology, 2007

35.0 y = 6E-05x2.6225 30.0 R 2 = 0.8193 25.0

20.0 (grams) 15.0

Weight 10.0

5.0

0.0 60 80 100 120 140 160 Fork length (mm)

Figure 7. Salmonid measurements from 2007 San Geronimo Creek monitoring of fork length and wet weight plotted for coho smolts.

Coho Salmon - 2006/2007 Year-Class Monitoring In 2008, the San Geronimo Creek trap captured 413 new coho smolts and the mark and recapture data resulted in a 38% trap capture probability and population estimate of 1,609 (±135) coho smolts (Table 1).

The peak coho smolt migration in 2008 occurred in week 7, April 28-May 4, with 98 new smolts captured during the week (Figure 8). The average coho smolt fork length was 106.7 mm (±7.6), weight was 12.5 grams (±2.6), and the K value was 1.02 (±0.1), presented in Table 2, and individual data are plotted in Figure 10. Grouping the coho smolts by week of capture, there was no significant difference in smolt size during the individual weeks of the outmigration period (Figure 9). A total of 2 coho salmon smolts were observed in the Larsen Creek trap, and 5 coho smolts in the Arroyo Creek trap.

There were 46 coho fry observed in 2008, with 41 in San Geronimo Creek, 5 in Arroyo Creek, and none in Larson Creek, all <85mm with no marks.

San Geronimo Coho Smolts 2008 DARR

450 0.8 DARR Estimate 400 New Captures 0.7 Capture Probability 350 0.6 300 0.5 250 0.4 200 0.3 150 Capture Probability

Number of coho smolts 0.2 100

50 0.1

0 0 1 2 3 4 5 6 7 8 9 10 11 Week

Figure 8. Outmigrant coho smolt captures, capture probability, and population estimates from 2008 monitoring in San Geronimo Creek. 9 Salmon Protection and Watershed Network (SPAWN)

2008 San Geronimo Coho Smolts

140 120

120 100 100 80 80 60 60 40 Fork Length 40 20 20 Weekly Abundance (#) 0 0 Mar. Mar. Mar. Apr. 7- Apr. Apr. Apr. May 5- May May May 18-23 24-30 31- 13 14-20 21-27 28- 11 12-18 19-25 26 - Apr. 6 May 4 June 2 1 2 3 4 5 6 7 8 9 10 11 Weeks

Figure 9. Coho smolt weekly average length and abundance in San Geronimo Creek in 2008.

San Geronimo Creek Coho Smolt Physiology, 2008

25.0

20.0 y = 4E-05x2.6835 R2 = 0.8554 15.0 (grams) 10.0

5.0 Weight 0.0 80 90 100 110 120 130 140 Fork length (mm)

Figure 10. Salmonid measurements from 2008 San Geronimo Creek monitoring of fork length and wet weight plotted for coho smolts.

Steelhead 2004/2005 Year Class Monitoring The San Geronimo Creek trap sampled 117 steelhead smolts and the mark and recapture data was used to estimate a 15% trap capture probability and estimate a population of 938 (±243) smolts for the year (Table 3). The peak in steelhead smolt migration occurred in during the first 2 days of trap operation in week 1, from April 22-24, with 36 smolts captured (Figure 11).

Average fork length and weight data for steelhead juveniles and smolts are presented in Tables 4 and 5, respectively. The Fulton Condition Factor K value was 1.11 (±0.2) for steelhead parr with smoltification scores of 2-3 and was 1.02 (±0.1) for steelhead with a smoltification score of 4 (Tables 4 -5). The fork length and wet weight measurements were plotted in Figure 12.

There were 2,603 steelhead fry observed in San Geronimo Creek trap in 2006, all <85mm in fork- length

10 Salmon Protection and Watershed Network (SPAWN)

Table 3. Summary of steelhead smolt population estimates from San Geronimo Valley (SGV) and total Lagunitas Creek Watershed (LCW). SGV Steelhead – SGV DARR DARR SGV SGV Trap estimate Total LCW SGV % of Year New Recapture Efficiency Steelhead TOTAL 2006 117 22 15% 938 (±243) 4,738* 20% 2007 160 20 12% 1,728 (±364) 9,152* 19% 2008 112 13 12% 1,112 (±310) 1,866* 60% Average 130 18 13% 1,259 5,509* 33% * Estimate data reported from MMWD/Stillwater Sciences estimate, all other data calculated from DARR 2.0.

Table 4. Summary of measurements from San Geronimo Creek steelhead smolts with smoltification code 4.

Steelhead weight Steelhead fork length Fulton’s Condition Factor Year (grams±STDEV) (mm±STDEV) (K±STDEV) 2006 38.9 (±20.3) 152.5 (±25.8) 1.02 (±0.1) 2007 57.1 (±16.9) 179.5 (±16.1) 0.97 (±0.1) 2008 58.5 (±19.5) 180.9 (±21.1) 0.98 (±0.3)

Table 5. Summary of measurements from San Geronimo Creek steelhead parr with smoltification codes 2-3.

Steelhead weight Steelhead fork length Fulton’s Condition Factor Year (grams±STDEV) (mm±STDEV) (K±STDEV) 2006 19.8 (±12.3) 116.8 (±12.3) 1.11 (±0.2) 2007 22.7 (±14.3) 123.5 (±28.0) 1.07 (±0.1) 2008 11.0 (±5.6) 98.72 (±14.8) 1.07 (±0.1)

San Geronimo Creek Steelhead Smolts 2006 DARR

300 0.165 DARR Estimate 250 New Captures 0.16 Probabilty of Capture 0.155 200 0.15 150 0.145 100 0.14 Capture Probabilty 50 Number steelhead smolts 0.135

0 0.13 1 2 3 4 5 6 7 8 Week

Figure 11. Outmigrant steelhead smolt captures, capture probability, and population estimates from 2006 monitoring in San Geronimo Creek.

11 Salmon Protection and Watershed Network (SPAWN)

San Geronimo Steelhead Parr Physiology, 2006 San Geronimo Creek Steelhead Smolt Physiology, 2006 70 160 60 y = 4E-05x2.7457 140 y = 2E-05x2.83 R2 = 0.9272 50 120 R2 = 0.9798

100 40

80 30 60

Weight (grams) 20 Weight (grams) 40 10 20

0 0 80 100 120 140 160 180 200 220 240 60 80 100 120 140 160 180 200 Fork length (mm) Fork length (mm)

Figure 12. Steelhead smolt and parr measurements of fork length vs. wet weight plotted from 2006 San Geronimo Creek monitoring.

Steelhead 2005/2006 Year Class Monitoring The San Geronimo Creek captured a total of 160 new steelhead smolts (180 total captures, 160 new captures, 20 recaptures) and the mark and recapture data was used to estimate a 12% trap capture efficiency and a population of 1,728 (±364) smolts outmigrating from the San Geronimo sub-watershed using DARR 2.0 software (Table 3). Two peaks in steelhead smolt migration occurred in 2007 with 32 smolts in week 6 and 33 smolts in week 8 (Figure 13).

The K value was 0.97 (±0.1) for steelhead with a smoltification score of 4 and the K value was 1.07 (±0.1) for steelhead parr with smoltification scores of 2-3 (Tables 4 & 5). The steelhead smolt and parr fork length and wet weight measurements are plotted in Figure 9. A total of 25 steelhead smolts were observed in the Larsen Creek trap, and 8 steelhead smolts in the Arroyo Creek trap.

There were 8,124 steelhead fry observed in 2007, with 4,582 steelhead fry in San Geronimo Creek, 3,345 steelhead fry in Arroyo, 197 steelhead fry in Larsen Creek, all with no fin clip marks and <85mm. In 2007, we reached our allowable permitted catch of fry and so we opened the back of the trap, which allowed only fry to pass through, beginning on May 6th. The trap remained in this condition until the end of monitoring in June. Thus, many more fry would have been captured if not for the limit set by the research permit for total juvenile steelhead catch.

San Geronimo Creek Steelhead Smolts 2007 DARR

325 DARR Estimate 0.24 300 New Captures 275 250 Capture Probability 0.19 225 200 0.14 175 150

smolts 125 0.09 100 75 0.04 50 Capture Probability Number of steelhead 25 0 -0.01 1 2 3 4 5 6 7 8 9 10 11 Week

Figure 13. Outmigrant steelhead smolt captures, capture probability, and population estimates from 2007 monitoring in San Geronimo Creek. 12 Salmon Protection and Watershed Network (SPAWN)

San Geronimo Steelhead Smolt Physiology, 2007 San Geronimo Creek Steelhead Parr Physiology, 2007

140.0 80.0

2.9291 120.0 y = 1E-05x 70.0 2.8475 R 2 = 0.8881 y = 2E-05x 60.0 2 100.0 R = 0.9776 50.0 80.0

(grams) 40.0 60.0 30.0 40.0 Weight (grams) Weight 20.0

20.0 10.0

0.0 0.0 140 160 180 200 220 240 60 80 100 120 140 160 180 200 Fork length (mm) Fork length (mm)

Figure 14. Steelhead smolt and parr measurements of fork length vs. wet weight plotted from 2007 San Geronimo Creek monitoring.

Steelhead 2006/2007 Year Class Monitoring The San Geronimo Creek trap captured 112 new steelhead smolts and the mark and recapture data was used to estimate a 12% trap capture efficiency and estimate a population of 1,112 (±310) steelhead smolts outmigrating from the San Geronimo sub-watershed (Table 3). The peak steelhead smolt migration occurred in week 6, April 21-27, with smolt 32 new smolts captured (Figure 15).

Average fork length and weight data for steelhead smolts and parr are presented in Tables 4 and 5, respectively. Grouping the steelhead smolts by week of capture, there was no significant difference in smolt size during the individual weeks of the outmigration period (Figure 16). The K value was 0.98 (±0.3) for steelhead with a smoltification score of 4 and 1.07 (±0.1) for steelhead parr with smoltification scores of 2-3 and (Tables 4 -5). The fork length and weight measurements were plotted in Figure 17. There were 2 steelhead smolts captured in Larsen Creek, while a single steelhead smolts was trapped in Arroyo Creek.

There were 3,037 steelhead fry observed in 2008, with 1,778 steelhead fry in San Geronimo Creek, 1,093 steelhead fry in Arroyo, 166 steelhead fry in Larsen, all with no marks and <85mm. However, the total number of fry is not accurate and represents a fraction of the total population because the back of the Arroyo Creek trap was opened for 4 of 7 days each week, which allowed fry to pass through freely while smolts remained captured in front compartment of the trap. Many more fry would have been captured if not for the limit set by the research permit for total juvenile steelhead catch.

San Geronimo Creek Steelhead Smolts 2008 DARR 2.0

275 0.3

250 DARR Estimate New Captures 225 0.25 Capture Probability 200 0.2 175

150 0.15 125

100 Capture Probability 0.1

Number of steelhead smolts 75

50 0.05

0 0 1 2 3 4 5 6 7 8 9 10 11 Week

Figure 15. Outmigrant coho smolt captures, capture probability, and population estimates from 2008 monitoring in San Geronimo Creek. 13 Salmon Protection and Watershed Network (SPAWN)

2008 San Geronimo Creek Steelhead Smolts

250 35 Series2 30 200 Series1 25

150 20

100 15 10 Fork Length (mm)

50 Weekly Abundance 5

0 0 Mar. Mar. Mar. Apr. 7- Apr. Apr. Apr. May 5- May May May 18-23 24-30 31- 13 14-20 21-27 28- 11 12-18 19-25 26 - Apr. 6 May 4 June 2 1 2 3 4 5 6 7 8 9 10 11 Weeks

Figure 16. Steelhead smolt weekly average length and abundance in San Geronimo Creek in 2008.

San Geronimo Creek Steelhead Smolt Physiology, 2008 San Geronimo Steelhead Parr Physiology, 2008

45.0 160.0 40.0 2.9854 y = 1E-05x 140.0 2 y = 0.0003x2.3376 35.0 R = 0.9571 120.0 R2 = 0.6542 30.0

100.0 25.0

80.0 20.0

60.0 15.0 Weight (grams)

Weight (grams) 40.0 10.0

20.0 5.0

0.0 0.0 100 125 150 175 200 225 250 275 50 70 90 110 130 150 Fork length (mm) Fork length (mm)

Figure 17. Steelhead smolt and parr measurements of fork length vs. wet weight plotted from 2008 San Geronimo Creek monitoring.

Other Aquatic Organisms A summary of aquatic organism captures other than salmonids are presented in Table 4. The first ever Louisiana crayfish, a common invasive invertebrate throughout North America, was sampled in San Geronimo Creek in 2007. These crawdads are found in the MMWD reservoirs and one possibility is that this species has now emigrated to San Geronimo Creek from these sources (2006, SPAWN).

Table 6. Summary counts of non-salmonid species recovered in smolt traps. Species Individuals Observed 2006 2007 2008 Louisiana crayfish (Procambarus clarkii) 0 1 0 Freshwater Sculpin (Cottus sp.) 1 0 1 Bluegill (Lepomis macrochirus)* 6 0 0 Bullfrog (Rana catesbeiana)* 5 5 0 Pacific newt (Taricha sp.) 11 13 1 Three-spined Stickleback (Gasterosteus aculeatus) 2 12 14 Signal Crayfish (Pacifastacus leniusculus) 23 108 50 California Roach (Hesperoleucus symmetricus) 99 164 86 Pacific lamprey ammocoetes (Lampetra tridentate) 90 43 246 *Non-native, invasive species is a predator on salmon eggs and fry. 14 Salmon Protection and Watershed Network (SPAWN)

Discussion

San Geronimo Valley Coho Smolt Production The monitoring of outmigrating salmon smolts has resulted in detailed population and physiology information validating the importance of the San Geronimo Valley sub-watershed in contributing an estimated average of 39% of the overall coho production across the Lagunitas Creek watershed during this study period.

Coho smolt new captures and population estimates were larger each year than those for steelhead in the SGV. The peak coho migration period occurred in late April to early May during each of the three years of monitoring. All years do show that coho smolt migration is greatly reduced and almost non-existent by the first week of June. Comparisons of coho and steelhead smolt lengths captured each week in 2008 did not reveal significant differences in smolt size from either species (Figures 12 &13), indicating that smolt size may not determine migration timing. However, coho smolts were captured within the first 2 days of trapping operations along San Geronimo Creek in all years, indicating that the beginning of the coho outmigration may occur before traps were set, possibly missing outmigration of the largest smolts if they lead the outmigration, and resulting in population estimates that should be considered minimum estimates. Based on these limited observations, watershed managers and planners should delay any instream work that may impact salmonids smolt migration until mid June or later to avoid disturbance of these sensitive fish.

The measured fork length, weight, and condition factor of SGV coho smolts appear to be very similar to those observed in nearby sub-watersheds (Table 7). However, due to the physical transformation taking place during smoltification, in which smolts take on a more elongated and fusiform shape, weight and condition factor comparisons between sub-watersheds may not be as useful as comparisons of fork length alone. New coho smolt average fork lengths measured at SGV when compared to new coho smolts measured downstream at the MMWD Lagunitas trap and were 6.5 mm smaller in 2006, 4.7 mm smaller in 2007, and 0.5 mm smaller in 2008. The average fork length of new coho smolts measured at the Lagunitas trap dropped each year by a larger value than average fork length dropped each year in the SGV. When average fork lengths of recaptured coho smolts measured at the Lagunitas trap were compared to those of recaptured coho smolts with SGV marks, the size difference no longer existed, with SGV smolts recaptured in 2006 have longer average fork lengths that those marked from LCW, and LCW lengths slightly exceeded SGV lengths 2007-2008 (Tables 9 &10). Therefore, coho smolts emanating from SGV increased in size during their outmigration and essentially reached the same size as average new smolts captured for the first time at the downstream Lagunitas trap (assuming these new smolts originated in LCW).

It is important to note that with a SGV trap capture probability, or trap efficiency, of 23-45% (average 35%) there are many SGV smolts that arrive at the Lagunitas trap without markings and cannot be distinguished from smolts raised in the LCW. In 2006, of the 92 coho smolts that were originally marked at the SGV trap and then recaptured at the Lagunitas trap, approximately 50% were recaptured < 7 days later and a cumulative total of 94% were recaptured by the week following their initial marking period (SWS LFA, 2008). It is generally found that SGV juvenile coho are smaller than LCW coho based on measurements of coho during MMWD summer surveys, so the influence of unmarked SGV coho smolts on the overall LCW smolt fork length average is likely reducing the average and masking some differences that may occur in smolt sizes observed.

Winter and spring flow refuge has been identified as the primary limiting factor for coho recovery in the greater Lagunitas Creek watershed, and our data support that this is very true for salmonid early life-stages (SWS, 2008). The incised channel morphology and relative lack of inset or major floodplains in the SGV due to a combination of historical disturbances in the watershed and more recent creekside development over the last 50 years does not support much high-flow refuge for juvenile salmonids. San Geronimo Creek recorded its highest peak flow on record on December 31, 2005 (Water Year 2006), with an instantaneous peak of about 3,940 cfs (SWS 2008). The effects of this flow event are apparent in the fluctuations in juvenile and smolt populations

15 Salmon Protection and Watershed Network (SPAWN) observed in this and other studies. Juvenile surveys performed by MMWD in the summer of 2006 revealed that the juvenile year-class in the SGV was very low, estimated at 1,842 with an average SGV juvenile population estimate of 6,580 (Ettlinger et al., MMWD). This correlates with our observation of low smolt production from this year class that was observed in Spring 2007. However, the SGV coho smolt population in Spring 2006 was estimated as the largest in the current study period and was barely impacted by the high flows when compared to Spring 2008 population (Table 1). Therefore, the high flows had a detrimental effect on the redds, incubating salmonid embryos, and emerged fry when the flood occurred, and the lack of high flow refuge in the SGV was more of a limiting factor to the survival of 0+ salmonid embryos and fry than it was to 1+ year old parr and smolts.

Initial habitat and geomorphology surveys of the SGV within the larger LCW by Stillwater Sciences concluded the SGV would not likely be a large producer of coho salmon smolts, based on the lack of woody debris, and a relatively incised and confined stream channel (SWS LFA, 2008). The monitoring of outmigrating coho smolts shows the SGV sub-watershed in contributing an estimated average of 39% of the overall coho production across the Lagunitas Creek watershed during this study period, validating its importance for early life-stages of the coho.

Table 7. Summary of average coho smolt fork lengths from SPAWN (SGV), MMWD (Lagunitas), and NPS (Olema and Redwood Creeks). Coho fork length (mm±STDEV).

Year SGV Lagunitas Olema Redwood 2006 111.6 (±9.1) 117.3 (±12.4) 98.9 (±9.6) 97.7 (±8.3) 2007 110.5 (±9.7) 115.2 (±10.1) 116.4 (±10.9) 115.3 (±10.9) 2008 106.7 (±7.6) 107.2 (±8.9) 110.8 (±9.1) 109.0 (±8.8)

Table 8. Summary of new coho smolt physiology from Lagunitas Creek Watershed (LCW; MMWD data). LCW LCW Coho weight Coho fork length Fulton’s Condition Factor Year (grams±STDEV) (mm±STDEV) (K±STD) 2006 17.7 (±12.4) 117.3 (±12.4) 1.06 (±0.1) 2007 16.5 (±4.0) 115.2 (±10.1) 1.05 (±0.26) 2008 13.2 (±3.3) 107.2 (±8.9) 1.06 (±0.1)

Table 9. Summary of marked, recaptured SGV coho smolt physiology as measured at downstream LCW monitoring station. SGV downstream SGV downstream Coho weight Coho fork length Fulton’s Condition Factor Year (grams±STDEV) (mm±STDEV) (K±STD) 2006 14.5 (±3.3) 110.7 (±7.7) 1.05 (±0.09) 2007 16.3 (±2.5) 113.7 (±6.1) 1.10 (±0.08) 2008 13.3 (±2.6) 108.6 (±7.2) 1.00 (±0.1)

Table 10. Summary of marked, recaptured LCW coho smolt physiology as measured at downstream LCW monitoring station. LCW LCW Coho weight Coho fork length Fulton’s Condition Factor Year (grams±STDEV) (mm±STDEV) (K±STD) 2006 13.4 (±3.4) 108.5 (±8.8) 1.03 (±0.11) 2007 16.5 (±3.2) 115.1 (±7.1) 1.07 (±0.05) 2008 13.9 (±3.7) 109.6 (±9.1) 1.04 (±0.1)

16 Salmon Protection and Watershed Network (SPAWN)

San Geronimo Valley Steelhead Smolt Production The peak steelhead migration period occurred slightly before the peak coho smolt migration, primarily in late April each of the three years observations were made. The shorter monitoring period of 2006 may have missed the early phase of migration that year, but seems to have overlapped with peak smolt migration timing. Like coho, all years do show that steelhead smolt migration has almost ceased by the first week of June. Comparison of steelhead smolt lengths captured each week in 2008 did not reveal significant difference in smolt size (Figures 12), indicating that smolt size is not likely to determine migration timing. Steelhead smolt and juveniles observed in the monitoring Steelhead juveniles with smoltification codes 2-3 consistently show the highest K values (Table 5) and the strongest correlation in length to weight ratio, indicating that the San Geronimo sub-watershed habitat is very well suited for the needs of these fish. However, like coho, the smoltification of steelhead is likely to skew the length to weight relationship of these fish, making comparisons of weight and condition factor less accurate than fork length comparison.

San Geronimo Valley Salmonid Trends and Hypothesized Limiting Factors Monitoring of salmonids in the SGV and LCW has intensified in recent years due to coho salmon declines in this watershed and throughout the state to attempt to determine factors that affect salmonids early life stage habitat needs and guide restoration efforts. Factors hypothesized to influence juvenile salmonids in the LCW include negative effects of density-dependent coho growth in limited San Geronimo Creek habitat, an observed positive correlation of San Geronimo Creek February and March stream flows to population levels in summer, and recently a discovery of coho smolts occupying un-surveyed glides resulting in conservative historical estimates of fish abundance in San Geronimo Creek (Ettlinger et al., MMWD).

According to a Limiting Factors Analyses conducted on the LCW as a whole that assumed spawning adults and juvenile seeding were at stable maximums, the lack of high-flow refuge habitat was limiting juvenile survival over winter (SWS, 2008). In addition, this report also identified lack of emergent fry habitat and redd scour as other habitat conditions that could be limiting salmonid production in the LCW (SWS, 2008). The CA DFG has recommended several habitat enhancements for the San Geronimo Valley, including an increase of in-stream wood, elimination of migration barriers, and reduction of sediment runoff from unpaved roads and trail systems (DFG, 2004).

Current watershed efforts include smolt trap monitoring during the spring in the SGV with SPAWN operating 3 traps, and smolt monitoring in the lower Lagunitas Creek watershed with MMWD operating 1 trap. MMWD also performs juvenile population surveys during the summer months using snorkel surveys and electrofishing throughout the San Geronimo and Lagunitas Creek system. Winter spawner surveys are conducted by MMWD throughout the mainstem of Lagunitas, Devil’s and San Geronimo Creeks, and SPAWN surveys upwards of 12 tributaries to San Geronimo Creek. With continued monitoring efforts, more coho and steelhead population data can guide future management and restoration actions in the SGV and LCW.

Acknowledgments

SPAWN wishes to thank our dedicated volunteers and program partners for support of this project, including Julie and NoahLani Litwin, Mel Wright, the Marin Resources Conservation District, California Department of Fish and Game, Americorps Watershed Stewards Project, Eric Bjokrstedt (NOAA), Marin Municipal Water District, the Marin Community Foundation, Bella Vista Foundation, and Patagonia Foundation. Assistance with the technical review of this paper is gratefully acknowledged from Leslie Ferguson of the San Francisco Regional Water Quality Control Board and Michael Reichmuth, Fishery Biologist, Point Reyes National Seashore. Funding was provided through a combination of private donors, membership dues, and gift contributions.

17 Salmon Protection and Watershed Network (SPAWN)

References

Carlisle, S., M. Reichmuth, C. Brown and B.J. Ketcham. 2009. Long-term Coho Salmon and Steelhead Trout Monitoring in Coastal Marin County 2008 Annual Monitoring Progress Report. National Park Service, San Francisco Bay Area Inventory and Monitoring Program, Point Reyes Station, CA. prepared for the California Department of Fish and Game P0530415.

Duffy, Walter G., 2005. Protocols for Monitoring the Response of Anadromous Salmon and Steelhead to Watershed Restoration in California. California Department of Fish and Game Salmon and Steelhead Trout Restoration Account Agreement No. P0210565

Bjorkstedt, Eric P., 2005. DARR 2.0: UPDATED SOFTWARE FOR ESTIMATING ABUNDANCE FROM STRATIFIED MARK-RECAPTURE DATA. U. S. DEPARTMENT OF COMMERCE, National Oceanic and Atmospheric Administration, National Marine Fisheries Service, Southwest Fisheries Science Center, NOAA Technical Memorandum, NOAA-TM-NMFS-SWFSC-368.

Ettlinger, Eric, Evan Childress, Marisa Piovarcsik, and Gregory Andrew, 2007. JUVENILE SALMONID POPULATION MONITORING REPORT LAGUNITAS CREEK, MARIN COUNTY, CALIFORNIA FALL 2007. Marin Municipal Water District.

Gale, D. 2000. Summary of Common Trap Types. Yurok Tribal Fisheries Program. Memo to Outmigrant Trapping Workshop Participants, dated January 12, 2000.

MacFarlane R.B., S. Hayes, B. Wells. 2008. Coho and Chinook Salmon Decline in California during the Spawning Seasons of 2007/08, 2 February 2008, NMFS

McCarthy, Sarah G., John P. Incardona, and Nathaniel L. Scholz. Coastal Storms, Toxic Runoff, and the Sustainable Conservation of Fish and Fisheries. American Fisheries Society Symposium 64:7–27, 2008

Nickelson TE, Rodgers JD, Johnson SL, Solazzi MF. 1992. Seasonal changes in habitat use by juvenile coho salmon (Oncorhynchus kisutch) in Oregon coastal streams. Canadian Journal of Fisheries and Aquatic Sciences, Vol. 49, no. 4, pp. 783-789.

Peter B. Moyle, Joshua A. Israel, Sabra E. Purdy. 2008. Salmon, Steelhead, and Trout in California: Status of an Emblematic Fauna. Center for Watershed Sciences, University of California, Davis.

Pollard, W.R., G.F. Hartman, C. Groot, Phil Edgell, 1997. Field Identification of Coastal Juvenile Salmonids. Harbour Publishing, British Columbia, Canada.

Stillwater Sciences. 2008. Lagunitas limiting factors analysis: liming factors for coho salmon and steelhead. Final report. Prepared by Stillwater Sciences, Berkeley, California for Marin Resource Conservation District, Point Reyes Station, California.