2012 annual report biology - central arizona project...2012 annual report - biology 2 table of...

2012 Annual Report Biology

Scott Bryan Senior Biologist

2012 Annual Report - Biology

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Table of Contents List of Figures .................................................................................................................................. 3

List of Tables ................................................................................................................................... 4

Executive Summary ...................................................................................................................... 5

Introduction ................................................................................................................................... 7

A. Quagga Mussels .................................................................................................................... 8

B. Aquatic Weeds – Mark Wilmer Pumping Plant ............................................................... 17

C. Aquatic Weeds – Aqueduct .............................................................................................. 22

D. Caddisflies ............................................................................................................................ 26

E. Water Quality ....................................................................................................................... 35

F. Miscellaneous ...................................................................................................................... 36

1. Diatoms .................................................................................................................. 36

2. Integrated Pest Management Plan (IPM) ......................................................... 36

3. Vegetation Control in Recharge Basins ............................................................ 37

4. Sediment ................................................................................................................ 37

G. Meetings Attended and Presentations ............................................................................ 40

Pumping Plant Abbreviations:

MWP = Mark Wilmer Pumping Plant BSH = Bouse Hills Pumping Plant LHQ = Little Harquahala Pumping Plant HSY = Hassayampa Pumping Plant WAD = Waddell Pump/Generating Plant SGL = Salt Gila Pumping Plant BRD = Brady Pumping Plant PIC = Picacho Pumping Plant RED = Red Rock Pumping Plant TWP = Twin Peaks Pumping Plant SAN = Sandario Pumping Plant BRW = Brawley Pumping Plant SXV = San Xavier Pumping Plant SNH = Snyder Hill Pumping Plant BLK = Black Mountain Pumping Plant


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List of Figures Figure 1. Trend in mean number of veligers collected from MWP (A) and WAD (B) in the CAP from 2009-2012. .................................................................................................................... 9

Figure 2. Number of settled quagga mussels per square foot on quarterly settlement plates at CAP pumping plants in 2012. ................................................................................... 10

Figure 3. Percent of settled quagga mussels in each size category collected on quarterly settlement plates at CAP pumping plants in 2012. ............................................... 10

Figure 4. Maximum number of settled quagga mussels per square foot on semi-annual settlement plates at CAP pumping plants in 2012. ............................................................... 11

Figure 5. Number of settled quagga mussels per square foot on annual settlement plates at CAP pumping plants in 2012. ................................................................................... 12

Figure 6. Number of settled quagga mussels found in monthly bio-box observations in 2012. ............................................................................................................................................. 12

Figure 7. Water temperatures measured in bio-boxes at each of the CAP pumping plants. Shaded areas indicate periods when the source water was from Lake Pleasant........................................................................................................................................................ 13

Figure 8. Water temperatures (blue line) and the number of settled quagga mussels (red line) in bio-boxes at MWP (A) and SXV (B). .................................................................... 14

Figure 9. Daily biomass (cubic yards) of weeds collected by the CAP weed harvesting boat from 2010-2012. ................................................................................................................. 18

Figure 10. Total biomass (cubic yards) of weeds collected by the CAP weed harvesting boat from 2010-2012. ................................................................................................................. 19

Figure 11. Vegetation coverage maps produced from data collected in the CAP intake channel. ........................................................................................................................... 20

Figure 12. Example of downscan trip replay. This replay shows the heavy vegetation growth of 1-3' feet in a section of Pool Bouse during June 2012. ........................................ 24

Figure 13. Species composition of aquatic vegetation growing in Pool Bouse in June 2012. ............................................................................................................................................. 24

Figure 14. Species composition of aquatic vegetation growing in Pool Bouse in August 2012. ............................................................................................................................................. 25

Figure 15. Mean larval caddisfly abundance at sites in Scottsdale and at sites below the Salt Gila Pumping Plant. ..................................................................................................... 28

Figure 16. Mean larval caddisfly abundance (per square foot) found on substrates at six sites in the CAP canal in 2012. .................................................................................................. 28

Figure 17. Mean adult caddisfly abundance compared with water temperatures in the CAP from 2010-2012. .................................................................................................................. 29

Figure 18. Mean adult caddisfly abundance on sticky cards at individual sites in 2011 (green line) and 2012 (red line). ............................................................................................... 30


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Figure 19. Mean relative weight of catfish collected from the CAP canal in 2012. The grey bar represents a healthy population. ............................................................................. 31

Figure 20. Frequency of occurence of prey items found in catfish stomachs in 2012. Empty stomachs are not included. .......................................................................................... 32

Figure 21. Percent of harvested catfish that were unmarked and marked (fin clip). ..... 33

Figure 22. Bathymetric map generated from sediment mapping activities at BSH in August, 2012. ............................................................................................................................... 38

Figure 23. Bathymetric map generated from sediment mapping activities at SGL in September, 2012. ........................................................................................................................ 39

List of Tables Table 1. Number of quagga mussels settled on annual plates at CAP pumping plants in 2012. ............................................................................................................................................. 11

Table 2. Grass carp stocking goals from 1990-2010, and from 2011-2012 for each pool in the CAP. ....................................................................................................................................... 23

Table 3. Number of catfish stocked in 2011 and 2012 in the CAP canal. ......................... 27

Table 4. Number of catfish collected at each site in 2012. The number of fish sacrificed for stomach analysis is in parentheses. .................................................................................... 31


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Executive Summary In 2012, CAP faced many of the same biological issues as in the past, as well as several new challenges. With the addition of a biologist, monitoring and research activities were streamlined to take advantage of the available resources, and new technologies were implemented to provide a different perspective to existing issues. Also, CAP became an active participant in the scientific community, as data and results were presented at professional meetings throughout the year. This annual report summarizes the monitoring efforts and findings related to the primary biological issues addressed in 2012. Quagga Mussels – Adult quagga mussels expanded their southern range within the CAP in 2012, infesting areas that were previously thought to be low risk. SAN, BRW, SXV, and BLK all saw notable infestations at various times during the year. MWP and WAD continued to see high numbers of settled quagga mussels as well. With the increase in infestations at the southern plants, CAP saw direct impacts at both BRW and SXV. At BRW, one of the pumps experienced excessive vibration, likely due to a build-up on the trash racks. At SXV, a 5-year PM revealed that the stuffing box regulator was completely packed with quagga shells and the regulator could not be adjusted above 30 psi. Aquatic Weeds – The aquatic weed problem at Mark Wilmer was relatively quiet in 2012, as we collected less than half the amount of weeds as in 2011. The reduced weed loading is probably the result of decreased growth in the lake due to high levels of phytoplankton and blue-green algae, which tend to tie-up many of the nutrients essential to plant growth. The occurrence of phytoplankton and blue-green algae is cyclical, and increased weed growth could occur at any time. A new technology was utilized to provide vegetative coverage maps in the MWP intake channel on Lake Havasu. The maps and estimates of bio-volume will allow CAP to predict the timing of weed collection activities, as well as the biomass of weeds that will need to be collected. Not only will this technology improve efficiency, but it will allow CAP to implement vegetation control strategies that could minimize the need for weed collection activities. The mapping technology was also used in Pool Bouse to determine weed coverage. Coupled with weed collection techniques, CAP has gained a better understanding of the weed assemblage and can better predict when automatic trash rakes may need to be operated more frequently. The data also helps us to adjust stocking rates of grass carp to improve control of the vegetation. Caddisflies – Although caddisflies appear to be a broad public concern, CAP has found that less than 1% of residents living along the canal actually call to voice their concerns. Regardless, CAP feels that it has a responsibility to its neighbors to control the nuisance insect to the best of its ability. Since 2004, CAP has implemented a variety of


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control measures in an effort to reduce the impact of nuisance caddisflies. Although there have been varying degrees of success with each measure, none had been found to provide a level of control that was economical and effective. In 2011, CAP began to stock channel catfish into the canal as a biological control. Data collected from artificial substrates and "sticky cards" indicate that the predatory fish is providing some level of control, is relatively economical, and is environmentally safe. Water Quality – Water quality is as important to CAP customers as it is to CAP. With that in mind, water quality meters were installed at MWP, HAS, and WAD and provided real-time data to our customers. However, as the meters aged, they required increased maintenance and continuous calibration. In 2012, a plan was developed to remove the older meters and a new advanced water quality meter was scheduled to be installed near CAP Headquarters. This new unit will be installed in late 2013. Miscellaneous – Diatoms, weed control in recharge basins, an integrated pest management plan, and sediment mapping were among miscellaneous issues addressed in 2012.

• A diatom (single-celled algae) known as Cymbella (or Rock Snot), is an invasive species but is typically not cause for concern in the canal. It appears to be growing in highest concentrations in the WAD forebay. When it dies and separates from the substrate, it floats to the surface and appears as floating clumps of tissue paper during fall. Observations by CAP personnel suggest that abundance may be increasing. Heavy infestation of Cymbella has been known to clog intakes and cause differential at pumping plants and water treatment facilities.

• The Integrated Pest Management Plan that was originally drafted in 1999 was

updated to provide CAP with a comprehensive and environmentally sensitive approach to pest management. The draft plan will be finalized and implemented in 2013.

• CAP worked with the Arizona Department of Water Resources to approve the

use of copper-based herbicides to control vegetation in recharge basins. The use of herbicides provides an economic alternative to mechanical restoration of the basins and increases the time between maintenance activities. A product known as Earthtec was chosen because it is self-dispersing (for efficient application), is ANSI/NSF 60 certified for drinking water application, and is effective on a variety of aquatic vegetation species. Earthtec was applied on two occasions in 2012 with good results.

• Technology used for weed mapping was also used to provide bathymetric maps (bottom contours) in pumping plant forebays and in various sections of the canal to determine sediment deposition. This technology will help CAP target specific areas for sediment removal efforts.


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Introduction With 336 miles of aqueduct and over 40,000 acres of property to manage, CAP faces biological challenges on a regular basis. Prior to September 2011, many of these challenges were addressed by various organizational elements within CAP and technical assistance was provided by consultants (e.g. RNT Consultants, U.S. Bureau of Reclamation, Arizona State University, etc.). Some of the issues facing CAP include:

• Quagga mussels • Aquatic weeds • Terrestrial weeds • Caddisflies • Water quality • Fisheries management • Lake Havasu/Bill Williams • Invasive diatoms (Didymo and Cymbella) • Asian Clams • Multi-Species Conservation Program • Fish Barrier Management

In September 2011, CAP hired a biologist to streamline monitoring activities, develop research studies that will help to address the multitude of issues, represent CAP in the scientific community and ultimately, to provide economically responsible management recommendations based on sound techniques and robust data. In 2012, much of the ongoing monitoring work was modified so that sampling efforts would provide meaningful results in an efficient manner. Some existing methods were continued (e.g. veliger sampling, caddisfly cards) or modified (e.g. caddisfly substrates, water quality monitoring, settlement plates), and several new techniques were implemented (e.g. weed mapping, catfish stomach analysis, bio-brief reports). The following annual report is a comprehensive description of the sampling methods, results, and scientific interpretation of the work completed in 2012.


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A. Quagga Mussels Introduction Adult quagga mussels were first discovered in Colorado River reservoirs in 2007 (Lake Mead). A year later, microscopic young quagga mussels known as veligers were observed in plankton samples throughout the CAP aqueduct. Despite the large number of veligers present throughout the system, few adult mussels were found in the aqueduct and downstream pumping plants. The most likely reason for the sporadic settlement (attachment) was hypothesized to be an environmental parameter which was outside the tolerance limits of the mussel. Beginning in 2009, CAP monitored the abundance of live veligers in the aqueduct, the settlement of adults at pumping plants, and various environmental parameters. Periodic inspections of pumping plant structures (e.g. trash racks at MWP and WAD) were also conducted as needed, using a camera mounted on a remote operated vehicle (ROV). Although the focus of the monitoring program has remained unchanged over the past 4 years, the intensity of sampling has been altered based on our findings. Methods In 2012, veliger samples were collected weekly throughout the year at MWP, and weekly during the summer pumping months at WAD. A volume of water (250 liters) was pumped through a plankton net to obtain a sample. The sample was preserved (buffered alcohol) and taken to the lab where five replicate subsamples were used for identification and enumeration (estimated field density). Cross-polarized microscopy was used for positive identification of veligers.

To monitor adult settlement, three sets of plates (6" x 6" PVC) were deployed at each pumping plant. Each of the three chains had 2-5 plates (depending on water depth) spaced approximately 3 feet apart. Chains were removed (1) quarterly, (2) semi-annually, and (3) annually. Upon retrieval, adult quagga mussels were scraped from the plate and counted. No determination of mortality (dead or alive) was made, however size of each individual was estimated.

Microscopic quagga mussel veliger

Quagga mussels on a settlement plate


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Within each pumping plant, adult settlement was monitored using a bio-box. The bio-boxes are modified aquariums that are installed in-line with the raw water system, so they receive the same water as pumping plant service water (e.g. cooling water, fire water, HVAC). Bio-boxes were cleaned of all sediment and mussels in April and temperature loggers were installed in each bio-box to correlate quagga density with water temperature. Bio-boxes were evaluated each month (April – December) and the number and size of individuals was recorded.

Results In 2012, veliger densities were at their lowest levels since 2009 (Figure 1). The estimated number of veligers per liter never exceeded 21 in 2012, compared with numbers as high as 341 per liter in 2011. Although there were small spikes in density during June and September at MWP, the large spikes observed in 2010 and 2011 were not realized. At WAD, numbers were relatively low and showed no spikes throughout the summer.

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Figure 1. Trend in mean number of veligers collected from MWP (A) and WAD (B) in the CAP from 2009-2012.

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The highest settlement of adults continues to occur at MWP. On quarterly settlement plates, adults were found only at MWP, BSH, WAD, BRW, and SXV (Figure 2). Although there were no distinctive patterns of settlement evident on the plates, it appears as though the numbers were lower in November than in August. Size of settled mussels follows an expected pattern of smaller individuals during spring, progressively growing into larger individuals during winter (Figure 3).

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Figure 3. Percent of settled quagga mussels in each size category collected on quarterly settlement plates at CAP pumping plants in 2012.

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Figure 2. Number of settled quagga mussels per square foot on quarterly settlement plates at CAP pumping plants in 2012.


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Semi-annual settlement plates, which were collected in August, were similar to the quarterly plates, with quagga mussels only settling at MWP, BSH, WAD, BRW, and SXV. Plates at MWP had up to 2,960 mussels per square foot, BSH had up to 66 mussels per square foot, and the other three locations were all below 25 mussels per square foot (Figure 4). As a reference, a cumulative density of mussels approaching 9,500 individuals per square foot is likely to cause significant maintenance problems.

Annual plates collected in December differed from quarterly and semi-annual plates, with quagga mussels present at SGL, RED, and TWP, but not at BRW and SXV (Figure 5). Plates at MWP had settlement as high as 3,600 individuals per square foot, and BSH and WAD both had densities above 100 per square foot. At MWP, BSH, WAD, and SGL, densities were highest on the deepest plates, while plates near the surface had very few settled mussels (Table 1).

Table 1. Number of quagga mussels settled on annual plates at CAP pumping plants in 2012.

Plate Depth (~m) MWP BSH WAD SGL

1 28 0 0 1 2 848 71 4 6 3 476 43 2 7 4 920 27 17 5 5 1,800 -- 53 6


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Figure 4. Maximum number of settled quagga mussels per square foot on semi-annual settlement plates at CAP pumping plants in 2012.


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Some degree of quagga infestation was found in the bio-boxes at 50% of the pumping plants at various times of the year in 2012. During early summer, over 1,500 quagga mussels were attached in the bio-box at SAN, however water flow to the box was stopped in July due to plant maintenance activities, so persistence of the mussels could not be evaluated. Quagga mussels were consistently found at BLK, SXV, and MWP, while mussels were more sporadically found in bio-boxes at TWP, BRD, and WAD At MWP, quagga mussel settlement was relatively low until October, when it increased significantly through December (Figure 6).


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Figure 5. Number of settled quagga mussels per square foot on annual settlement plates at CAP pumping plants in 2012.

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Figure 6. Number of settled quagga mussels found in monthly bio-box observations in 2012.


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Water temperatures were recorded every six hours in the bio-boxes. Temperatures ranged from 55oF in the winter, to over 88oF during summer. Water temperatures in the western plants followed a similar pattern, with a slow rise during the summer months, followed by a steady decline from September through December (Figure 7). At Waddell, temperatures were highly dependent on whether water was being pumped into Lake Pleasant, or withdrawn from Lake Pleasant. In southern plants, water temperatures were more erratic, depending on both source water and surface warming (ambient air). Although there were no significant statistical correlations between quagga settlement in the bio-boxes and water temperatures (Spearman's R; p > 0.05), the graphs indicate that quagga densities were low with warmer water temperatures, and then increased when water temperatures fell below 80oF (Figure 8).

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Figure 7. Water temperatures measured in bio-boxes at each of the CAP pumping plants. Shaded areas indicate periods when the source water was from Lake Pleasant.

WAD


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Sediment (silt) built-up fairly rapidly in bio-boxes at TWP and SAN, and slowly built-up at SGL and BRW through the course of the year. Sediment deposition at other bio-boxes was minimal. Freshwater sponge was found primarily at RED, PIC, and BRD throughout 2012, an only in fall at MWP. Blue-green algae was observed in bio-boxes at various pumping plants throughout the year. Discussion Our findings of low veliger density in 2012 are consistent with densities reported by various agencies throughout the lower Colorado River (U.S. Bureau of Reclamation, Metropolitan Water District, Southern Nevada Water Authority, University of Nevada – Las Vegas). Reasons for the decreased numbers are unknown, but there has been speculation that the food base is limiting production. High water temperatures have also been thought to play an important role, however, mean water temperatures have been relatively consistent over the past three years. The lower densities of veligers in 2012 samples may explain the slightly lower number of

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Figure 8. Water temperatures (blue line) and the number of settled quagga mussels (red line) in bio-boxes at MWP (A) and SXV (B).


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quagga mussels on MWP 6-month settlement plates compared with previous years. However, throughout 2012, CAP personnel found that adult quagga mussels were more widespread in the system than at any time in the past. For example:

• In late 2011, a limited number of adult quagga mussels were found in Red Mountain Lake, a City of Mesa facility. The lake receives water from the CAP via the Mesa Turnout. In May 2012, Arizona Game and Fish Department found a significant infestation of quaggas in the lake. Although the infestation is probably the result of a failed filter, this is a location that had not seen quaggas in the past.

• In April 2012, a large number of settled (attached) quagga mussels were found

in the bio-box at SAN. This was considered to be a rare occurrence, since a large number of quaggas had not been found in a bio-box this far south in previous years.

• In late May 2012, an ROV inspection of the inside of the Phoenix Lake Pleasant

trash racks showed approximately 80% occlusion as a result of quagga mussel infestation.

• In late May 2012, pump #2 at BRW was started after sitting idle for several

months. Excessive vibration caused the pump to automatically shut down on several occasions and an ROV inspection was ordered. The ROV inspection revealed that there was a heavy infestation of quagga mussels on the trash rack, which likely caused the vibration and ultimate shut-down.

• As a result of the quagga findings on the trash rack at BRW, an inspection of the

strainer was ordered. The inspection in June 2012 revealed that there were 50-100 live quagga mussels in the raw water strainer. In addition, the two Filtomat's located on the service water pipe was also moderately infested with live quagga mussels and was full of shell debris. The two Filtomat's at SXV were also heavily infested with live quagga mussels of various sizes.

• In late June 2012, a large number of adult quagga mussels were found in Pool

Bouse, an 18-mile stretch of canal between the Buckskin Tunnel and the BSH. The quaggas were attached to vegetation throughout the section of aqueduct and were found during routine aquatic weed sampling.

• In November 2012, Ancala Golf Course in Scottsdale initiated a Zequanox treatment for a recent infestation of quagga mussels that were beginning to foul their irrigation system. Ancala receives water from CAP.

• During the annual fall outage, plant personnel at SAN, BRW, and SXV found moderate levels of quagga infestation in discharge lines, mud valves, and in various filters when performing routine maintenance. Personnel indicated that they have not seen infestation levels like this in the past.


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• In early December 2012, heavy infestations of quagga mussels were found at the Phoenix Anthem Turnout and at the Phoenix (Union Hills) Turnout.

• In mid-December 2012, the stuffing box regulator at SXV was fouled, likely due to a heavy infestation of quagga mussels.

In most cases, settlement plates were effective in showing presence/absence of quagga mussels, but did not give a good representation of the severity of infestation. Although plates at MWP showed heavy infestation throughout the year, plates at CAP's southern plants indicated that quagga mussels were not settling in high numbers. Observations and inspections throughout the year showed very different results, as there were infestations found throughout the system (see list above), especially at some of CAP's southernmost pumping plants. Some areas of the lower Colorado River experienced a die-off of large adult mussels, which was thought to be related to high surface water temperatures that extended longer than usual (reported by various agencies at the Interagency Quagga Mussel Team Meeting, December 5, 2012). Settlement plates at MWP showed a decreased number of settled adults in November, which may indicate some mortality due to temperature. In addition, annual plates at MWP, BSH, WAD, and SGL all showed significantly lower numbers of settled quaggas on plates higher in the water column. This indicates that higher water temperatures at the surface had a negative impact on quagga abundance. Monthly evaluation of bio-boxes at each of the pumping plants shows a consistent infestation of quagga mussels at the beginning of the system (MWP), and at the end of the system (BLK and SXV). The limited settlement on plates at BSH, and lack of settlement in bio-boxes and plates at LHQ and HAS indicates that only a small amount of quagga veligers are fit to settle in the western section of the canal. Previous reports (unpublished data) indicate that the pressures and forces exerted by the pumps and transport through the Buckskin Tunnel are causing a high level of damage and mortality. It was originally thought that cold, anoxic releases from Lake Pleasant, high levels of inorganic suspended solids, high levels of algal production, and high summer temperatures prevented significant settlement downstream of WAD. However, in 2012, CAP experienced infestation at the southernmost plants (BLK and SXV). Although water temperatures did not vary significantly from previous years, it is unknown whether possible changes in other environmental conditions could have allowed for the increased levels of settlement.


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B. Aquatic Weeds – Mark Wilmer Pumping Plant Introduction In recent years, MWP has experienced an increased frequency and volume of aquatic weeds. The weeds typically become entrained in the intake channel, either as individual plants that have been dislodged or as floating mats of dead material. Since there is currently no trash rake system at MWP, individual weeds and plant mats can accumulate on the racks. Mechanical removal methods (e.g. long-reach excavator) are used to remove weeds from the trash racks; however, the weeds (especially the mats) have the potential to appear suddenly and overwhelm the pumping plant. Eventually, this accumulation could lead to differential and pump shut-down. Therefore, a weed harvesting boat is operated within the intake channel from July through October to ensure that floating mats do not reach the pumping plant. To better address the weed loading at MWP, a trash rake system is currently being designed that will handle the majority of weed issues and ensure that plant operations are not affected by the weeds. For the foreseeable future, the weed collection boat will continue to be operated to ensure that the largest floating mats will be collected before reaching the plant. CAP continues to study patterns of weed growth in the intake channel, the Bill Williams delta, and Lake Havasu, so that the most effective and efficient control techniques can be utilized. Methods In 2011, Dr. John Madsen from Mississippi State University initiated a weed study in Lake Havasu aimed at gaining a better understanding of the distribution of vegetation throughout the lake, describing the seasonal life history of the plants (phenology), and monitoring plant mat dispersal (movement). Dr. Madsen's study continued in 2012 with more emphasis on tracking the movements of floating plant mats. A final report will be made available in 2013. Black and Veatch completed a project in early 2012 which provided potential alternatives for installation of trash rake systems at MWP. Their recommendations are currently under consideration by CAP. Since 2010, CAP has been tracking the amount of weeds removed by the weed harvesting boat from the intake channel. This was continued in 2012 by counting the number of boat loads and multiplying it by an estimated six cubic yards per boat load. In addition, loads were randomly sampled daily to determine the species composition

Aquatic vegetation growth in Lake Havasu


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of the weeds. In 2012, a new technology was utilized to determine the extent of weed growth within the intake channel itself. This technology uses data collected from sonar transects to create bathymetric (bottom contour) and vegetation coverage maps. From June through September, CAP used a sidescan and downscan sonar to log data on a monthly basis. Transects were spaced approximately 20-25 meters apart and the entire intake channel was mapped. Data was uploaded and comprehensive vegetation maps were generated. Field verification of the sonar data was accomplished by randomly sampling within the intake channel. A thatch rake was lowered to the bottom and retrieved, where presence/absence of vegetation was verified and identified. The Bill Williams Delta was also randomly sampled using the thatch rake to determine species presence. Results After much discussion with the U.S. Fish and Wildlife Service, CAP was allowed to go outside of the jetty in 2012 to collect floating weed mats (into the Bill Williams National Wildlife Refuge). Weed collection crews were on-call from July 9th through September 16th. Despite the expanded area available for weed collection, the "weed season" was a shorter duration and less intense than in previous years (Figure 9). The biomass of weeds collected in 2012 was 51% lower than 2011, and 45% lower than in 2010 (Figure 10).

Figure 9. Daily biomass (cubic yards) of weeds collected by the CAP weed harvesting boat from 2010-2012.

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Figure 10. Total biomass (cubic yards) of weeds collected by the CAP weed harvesting boat from 2010-2012.

Weed samples were collected from July 25-29, and from August 7-14 by crews on the weed harvesting boat (13 total samples). Weed samples consisted entirely of spiny naiad, with only one sample containing 1% southern naiad on August 14th. Bathymetric maps created from sonar data collected by CAP were very similar to bathymetric maps produced by independent contractors in the past. The intake channel is approximately 62 surface acres with an average depth of 18.1 feet. Weed coverage maps (Figure 11) showed heavy growth in the intake channel where flows were highest (i.e. along the southern shoreline of the jetty). Growth was heaviest in June (14.55% biovolume) and July (20.37%), then decreased substantially in August (9.9%) and was nearly non-existent in September (0.5%). Field verification of weed coverage agreed with the sonar output. In addition, samples collected using the thatch rake consisted almost entirely of spiny naiad, similar to samples collected on the weed harvesting boat. Random samples collected in the Bill Williams delta showed sporadic growth of spiny naiad in deeper water (15-24'), and heavy growth of southern naiad and sago pondweed in shallower water (3-9'). Eurasian watermilfoil (milfoil), an invasive aquatic weed species, was found sporadically in the Bill Williams delta.

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Conclusions Decreased weed collection in 2012 could be the result of a variety of factors. First, there was a significant cyanobacteria bloom (Microcystis; Dr. David Walker, University of Arizona) in Lake Havasu throughout much of 2012. This blue-green algae likely tied-up nutrients that would otherwise be available for growth of rooted aquatic vegetation. Several biologists who typically work in Lake Havasu commented that they believed vegetation growth was not as severe in 2012 based on their observations (Kirk Koch, Bureau of Land Management; Dick Gilbert, U.S. Fish and Wildlife Service; various biologists at MSCP meeting in Laughlin, NV). Also, large mats of vegetation formed in the Bill Williams delta, similar to previous years. However, weather and wind conditions held these mats in the back of the delta and as a result, floating vegetation did not approach or come around the jetty into the CAP intake channel. Vegetation coverage maps provided an interesting look at weed growth within the CAP intake channel. Coupled with random samples of weeds collected by the harvesting boat and weeds sampled using the thatch rake, the data indicates that the majority of early season weed mat formation (July and August) is the result of spiny naiad growing and dying within the intake channel itself. In previous years, late season mats consisted primarily of sago pondweed and southern naiad (personal observations by CAP personnel), suggesting that these mats form in the back of the Bill Williams delta.

Figure 11. Vegetation coverage maps produced from data collected in the CAP intake channel.

June 2012 July 2012

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If this pattern continues, then CAP may be able to reduce costs associated with weed collection by better managing the weed growth within the intake channel. Also, this data suggests that weed mats are not coming from upstream areas of Lake Havasu, which significantly lowers the weed loading potential at MWP. A decreased weed loading potential reduces the size and complexity of the trash rake system required at MWP (as determined by the Black and Veatch study). The presence of milfoil in the Bill Williams delta is concerning because this invasive weed has the potential to rapidly spread and create dense stands of rooted vegetation. It reproduces by both seed and fragmentation, so it can easily move throughout the lake and potentially into the canal system (it was found in Pool Bouse in 2012). Not only do the dense mats of milfoil have a negative impact on recreation in a lake, but they also increase sedimentation, reduce oxygen, and potentially clog intake screens.


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C. Aquatic Weeds – Aqueduct Introduction The extent of aquatic vegetation growth in the CAP aqueduct (canal) has been relatively unknown since completion of construction. Reclamation biologists made recommendations to stock grass carp in 1990 to control vegetation and those recommendations have been generally followed for the past 21 years. However, it is unknown if those recommendations were based on actual weed growth, or if they were preventative recommendations simply based on pool size. Whichever the case, the canal has been generally void of rooted aquatic vegetation, except for Pool Bouse, which experiences a relatively high density of annual weed growth (Dallas Hillhouse, personal communication). Despite the lack of rooted vegetation, there have been periods when the canal is susceptible to algae growth (phytoplankton and filamentous algae). Typically, algae growth has not caused issues for CAP and the filamentous algae has not been observed for several years. In Pool Bouse, rooted vegetation growth can be heavy at times. During summer and fall, plants break off and form mats that accumulate at BSH. A Bosker style trash rake system is run both manually and automatically, depending on weed loading. Weed monitoring in Pool Bouse should be aimed at gaining a better understanding of species composition and weed coverage so that the proper control techniques can be implemented. Methods Since the stocking goals and rates for grass carp in the canal had not been evaluated since 1990, it was important to revisit the recommended stocking rates to determine if they matched current conditions. It is unknown why sections of the canal were designated for low, medium, or high stocking rates in 1990, so in 2011 rates were adjusted based on observations from maintenance crews. Table 2 shows the change in stocking rates. In 2012, grass carp stocking was focused on Pool Bouse due to the high vegetation growth and change in designation to a "high" stocking rate. Approximately 5,600 grass carp were stocked into Pool Bouse in November 2012. Sonar mapping, as described above, was used to determine vegetation coverage in Pool Bouse. Three parallel transects were run in the 18-mile section of canal, one on each side and one down the middle. Data was uploaded to produce vegetation

Grass carp stocked into Pool Bouse


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Table 2. Grass carp stocking goals from 1990-2010, and from 2011-2012 for each pool in the CAP.

Stocking Location

Wetted Surface Acres

1990-2010 Stocking Rate

Target No. of Fish

2011-2012 Stocking Rate

Target No. of Fish

Estimated No. of Fish 01/01/12

Pool Bouse 317 LOW (6/acre) 1,902 HIGH (30/acre) 9,510 3,795 BSH – LHQ 340 HIGH (25/acre) 8,500 MED (15/acre) 3,400 5,177 LHQ – HSY 630 MED (15/acre) 9,450 LOW (6 acre) 3,150 5,378 HSY – SGL 693 MED (15/acre) 10,395 LOW (6 acre) 3,465 3,535 SGL – BRD 567 MED (15/acre) 8,505 LOW (6 acre) 2,835 3,793 BRD – PIC 35 LOW (6/acre) 210 LOW (6 acre) 175 91 PIC – RED 108 HIGH (25/acre) 2,700 LOW (6 acre) 540 1,331 RED – TWP 120 HIGH (25/acre) 3,000 LOW (6 acre) 600 1,364 TWP – SAN 40 MED (15/acre) 600 LOW (6 acre) 200 253 SAN – BRW 20 MED (15/acre) 300 LOW (6 acre) 100 127 BRW - SXV 40 MED (15/acre) 600 LOW (6 acre) 200 249

coverage maps. Sampling was conducted in June and August.

To determine species composition in Pool Bouse, sample sites were established every 0.5 miles through the 18-mile pool. A weighted thatch rake was lowered over the side of the boat at each site, dropped to the canal bottom and retrieved. Vegetation was identified and percent composition was estimated and recorded in the field. Samples were collected in conjunction with canal mapping during June and August.

Results Vegetation mapping in a canal using the Lowrance HDS-7 technology had not been previously attempted. As a result, algorithms needed to be adjusted to account for the steep sloping sides and relatively small sample area. In addition, the heavy bed of vegetation growth along the entire bottom (as shown in the "trip replay" feature of the sonar; Figure 12) prevented the sonar from finding the "true" bottom (canal invert), so bathymetric maps and vegetation maps that were generated must be interpreted carefully. Rake samples in June show an interesting progression of species composition throughout Pool Bouse, as the upper portions were dominated by sago pondweed, the middle by chara, and the lower areas by spiny naiad (Figure 13). In August, chara dominated most of the canal, but sago pondweed was still found near the outlet tunnel and some spiny naiad persisted near BSH (Figure 14). Southern naiad was found only sporadically and was generally more prevalent in the upper sections. Eurasian watermilfoil was found in two samples during June and one sample in August.

Weeds collected on rake at Pool Bouse


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Figure 13. Species composition of aquatic vegetation growing in Pool Bouse in June 2012.

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Figure 12. Example of downscan trip replay. This replay shows the heavy vegetation growth of 1-3' feet in a section of Pool Bouse during June 2012.


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Figure 14. Species composition of aquatic vegetation growing in Pool Bouse in August 2012.

Conclusions Although the bathymetric and vegetation coverage mapping did not give a true representation of the bottom contours and weed growth, the image projected by the downscan sonar (trip replay) showed the heavy bed of vegetation that grows throughout this section of canal. Coupled with the data from rake samples, it is evident that grass carp densities are too low to effectively control vegetation. The stocking of 6,000 grass carp in November 2012 should help to better manage the vegetation growth in the future. In June, the trash rake at BSH picked up primarily sago pondweed, which indicates that plants nearest the Buckskin Tunnel were being uprooted by the higher flows and entered the forebay as floating mats. During August, plants observed from the trash rakes were primarily chara, but also included spiny naiad and sago pondweed. The combination of weeds in August probably reflects timing of senescence (death) of the plants. The presence of milfoil in the rake samples could be cause for concern and needs to be monitored closely. However, grass carp readily consume milfoil, so the invasive plant is not expected to spread successfully.

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D. Caddisflies Introduction In 2004, a nuisance insect was reported to CAP by Phoenix and Scottsdale residents. The insects were identified by Dr. David Walker (ASU) as Smicridea, a common genus of caddisfly that is indigenous to the Colorado River. Although 2004 was the first record of complaint by nearby residents, caddisflies were found in relatively high numbers in the CAP as early as 1993. It is likely that caddisfly swarms have been common since the canal was constructed, but were largely undetected because people did not live near the canal. The emergence of large numbers of adult caddisflies causes a nuisance because they swarm around people, flying into the mouth, eyes, nose, and ears. They make outdoor dining and entertaining uncomfortable during periods of high activity. Since 2004, CAP has implemented various monitoring and control strategies in an attempt to reduce the impact of the nuisance caddisflies. Control strategies have included dropping water levels, scraping, and bug zappers. CAP has also tested the use of biological controls (Bacillus thuringiensis and grass carp) and chemical controls (insecticidal soap and copper sulfate). Each of these strategies has shown limited or no success. Monitoring efforts have included the use of artificial substrates (larvae) and sticky cards (adults). Methods In 2012, caddisfly larvae were monitored using artificial substrates. The original substrates sampled by Reclamation (2007 - 2011) were set at three sites, at four different depths, with three replicates each. Statistical analysis of past data indicates that there was no significant difference in caddisfly abundance among the varying depths. Therefore, we reduced the number of substrates to three replicates at one depth at each of three sites (56th St. Horizon, and 124th St.). We also added three new sites downstream of the Salt Gila Pumping Plant (McDowell, McKellips, and Brown) to monitor caddisfly densities in populated areas where no methods of control were being used. In past years, Reclamation sampling of the substrates was erratic, with no consistent timing for sampling activities. In 2012, we sampled substrates every eight weeks beginning in February to establish a consistent data set. Artificial substrates consist of a 30 cm x 30 cm x 8 cm piece of concrete that mimics the material used in the canal lining. It is held in place by a chain. The substrate lays flat on the canal lining at a depth of approximately two meters. Substrates were retrieved and scraped into a large tub using a soft bristled brush. The scraped material was then transferred to a

Caddisfly larvae


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sample bottle with diluted 70% isopropyl alcohol. Samples were taken to the CAP lab and all insects were identified using a dissecting microscope. We continued to sample sticky cards to monitor trends in caddisfly hatches in 2012. Cards, which are sticky on both sides, were clipped to lathe stakes at 11-15 stations at each of four sites (Norterra Parkway, 56th Street, Horizon Park, and 124th St.). Cards were set on Monday mornings and retrieved the following day. Upon retrieval, each adult caddisfly was counted and recorded. Based on recommendations from a 2011 report (RNT Consultants), CAP began an in situ experimental stocking of catfish to determine if the caddisfly population could be reduced through fish predation. Approximately 6,000 channel catfish were stocked in various locations in 2011, and an additional 2,000 fish were stocked in 2012 (Table 3). Table 3. Number of catfish stocked in 2011 and 2012 in the CAP canal.

Date Norterra Parkway (MP 159)

56th Street (MP 169)

Horizon Park (MP 175)


4/12/11 450 1,200 900 450 9/27/11 300 1,500 1,200 5/21/12 100 400 400 6/14/12 100 8/21/12 500 500

Totals 950 3,600 1,400 2,050

To monitor catfish health and food habits in 2012, fish were collected quarterly at three sites (Norterra Parkway, 56th St. and 124th St.) by hook and line. An additional sample was collected in September, during the peak of the caddisfly hatch. The goal was to collect at least 10 fish from each of the sites. Each of the catfish was measured and weighed upon capture. Five of the fish at each site were sacrificed for stomach analysis, while all other fish were returned to the canal. When fish were difficult to catch at one site, additional fish were collected and sacrificed at another site. Stomachs were removed in the field and immediately iced. Once in the lab, stomach contents were identified and enumerated using a dissecting microscope. Prior to stocking in late May 2012, approximately 1,000 catfish were fin clipped (adipose fin) to determine general fish movement. About 400 marked fish were released at 56th St. and 124th St., respectively, and the remaining 200 fish were stocked downstream of Norterra Parkway. Presence or absence of a fin clip was recorded upon harvest. Results Caddisfly Population Monitoring Since Reclamation substrate data from past years was not collected in a consistent manner, 2012 data can be considered baseline. Larval caddisfly abundance was higher below the SGL than in Scottsdale from August through December (ANOVA; p < 0.05; Figure 15). At individual sites, larval caddisfly abundance was essentially equal


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throughout the year until August (Figure 16). In August, larval abundance at the 56th St. site was higher than the other two Scottsdale sites (ANOVA; p < 0.05). Below the SGL, larval abundance was significantly higher at the McKellips Road site than all other sites in November (ANOVA; p < 0.05).

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Figure 16. Mean larval caddisfly abundance (per square foot) found on substrates at six sites in the CAP canal in 2012.


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The mean number of adult caddisflies found on sticky cards follows a similar pattern from 2010-2012, with a small hatch in spring and more pronounced hatch in fall (Figure 17). In 2012, the mean number of adult caddisflies on cards was significantly lower than in past years (ANOVA; P < 0.05); however, the peak of the hatch was much later in the year and lasted through the middle of November. Mean caddisfly abundance on sticky cards was correlated with water temperatures (Spearman's Rank Correlation) to determine if the variables were related. Results indicate that water temperature on the day of collection is not significantly correlated with abundance, rather abundance increases two weeks after a change (increase) in water temperature (p < 0.05).

During 2011 and 2012, adult caddisfly abundance at 56th St. and 124 St. sites was significantly higher than abundances found at Norterra Parkway and Horizon Park (Figure 18; ANOVA; P<0.05).

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Catfish Health and Condition In 2012, 104 catfish were collected, of which 65 were sacrificed for stomach analysis (Table 4). The mean length of all catfish harvested was 19.64 inches, while the mean weight was 2.63 pounds. The longest fish harvested was 25 inches and the heaviest was 5.55 pounds. Table 4. Number of catfish collected at each site in 2012. The number of fish sacrificed for stomach analysis is in parentheses.

Date Norterra Parkway (MP 159)



January 2012 10 (5) 10 (5) 8 (5) April 2012 2 (2) 7 (7) 3 (3) July 2012 0 (0) 6 (6) 2 (2)

September 2012 10 (5) 13 (5) 10 (5) October 2012 6 (5) 10 (5) 7 (5)

Totals 28 (17) 46 (28) 30 (20)

Relative weight is a measure of the general condition of a fish. A healthy population of fish should have relative weights ranging from 95-105. A relative weight of 100 indicates that fish are in balance with their food supply. Fish with relative weight below 85 are underweight and may be too abundant for the food supply. Values over 105 indicate an overabundant food supply and the canal could likely support more fish. In 2012, mean relative weight ranged from a low of 78.6 in April to a high of 98.5 in September (Figure 19). For all sites combined, mean relative weight in April was significantly lower than any other month (ANOVA; p < 0.05), while all other months were statistically equivalent. During all months except September, catfish condition was below that of a healthy population. By site, catfish collected at 124th Street had a higher mean relative weight (107) than the other two sites in January (ANOVA; p < 0.05), but relative weights were statistically equal throughout the rest of the year.

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Figure 19. Mean relative weight of catfish collected from the CAP canal in 2012. The grey bar represents a healthy population.


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Food habits of catfish varied widely throughout the year, with aquatic insects dominating the diet in September and October (Figure 20). Nineteen of the 65 fish (29.2%) harvested throughout the year had empty stomachs, eight of which were in January. At least one fish had bird parts (typically feathers) in its stomach every month. Among the more unusual food items were Styrofoam, rocks, and bone fragments from a mammal.

Twenty-one catfish (32.3%) consumed caddisflies, either in the larval stage, adult stage, or both. The mean number of caddisflies in the catfish diet was 14.5 adults and 26.1 larvae. The most caddisflies a single catfish consumed was 51 adults and 84 larvae. Aquatic moths were prevalent in the catfish diet at Norterra Parkway and 56th Street during September and October. During those two months, 16 catfish ate an average of 172 moth larvae each. No aquatic moths were found in the diet of catfish at 124th St. Catfish Movement Marked catfish (fin clip) were captured during each of the sampling events after their initial stocking in May (Figure 21). The largest percentage of marked fish were captured at the Norterra Parkway site. No marked fish were caught at the SGL forebay when an additional sampling trip was taken in September.

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Conclusions Larval caddisfly abundance in 2012 was slightly lower than that found from 2008 through 2010, but significantly lower than the abundance found in 2007. However, Reclamation data should be interpreted with caution, since there was not a consistent interval of time between sample collections; timing between collections ranged from three months to a full year. Substrates were collected every eight weeks in 2012. When the 2012 substrate data is extrapolated to a larger scale, there is an estimated 19 million (near Scottsdale) to 52 million (below Salt Gila) caddisflies per mile of canal during late summer. Although this is a rough calculation of total abundance, it explains why the caddisflies are considered a nuisance by homeowners along the canal. The Glendale/Phoenix/Scottsdale/Mesa section of the canal is approximately 58 miles long with an estimated 1,091 homes along the canal. The 6.8 mile section between Check #21 and #22 has the highest density of homes near the canal in the Valley (33 per mile), and the homes are closer to the canal than any other area; approximately 65-85 feet from the water to the back fence of the home. This area has a high concentration of caddisfly larvae and not coincidentally, it generates the most customer complaints (13 in 2012). Although caddisfly abundance is nearly three times higher below the Salt Gila pumping plant, we receive very few calls from that area (2 in 2012). This section of canal has approximately 23 homes per mile, but the homes are an average of 165 feet from the canal. The sticky card data shows a relatively clear picture regarding the timing of the caddisfly hatch and its relationship to changes in water temperature. It was previously thought that there was a "magic" temperature that induces the caddisflies to hatch (~73oF). However, our data indicates that the hatch may be more related to a consistent increase in water temperature rather than a specific number. This is especially evident in 2012, when a canal breach in September resulted in a switch to

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Figure 21. Percent of harvested catfish that were unmarked and marked (fin clip).


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the cooler Lake Pleasant water. The hatch was delayed by several weeks, but as the temperatures began to rise once again in October, caddisflies resumed their fall hatch (despite water temperatures below 65oF). Although the sticky cards do not accurately reflect caddisfly densities, it is interesting to note that there are continually higher adult counts at 124th St. and 56th St. as compared to Norterra and Horizon. An explanation may be that both 124th St. and 56th St. have higher densities of homes and they are older neighborhoods, where vegetation is more dense and mature. Homes are relatively close to the canal, especially at 56th St., and may provide more accessible cover for the adult caddisfly. The high number of caddisfly larvae below the SGL, as compared to the Scottsdale area, may be related to a combination of food availability and the catfish stocking program. After flowing through most of the valley, CAP water below the pumping plant tends to be more productive and have larger phytoplankton blooms. Caddisflies feed on the phytoplankton, and thus are likely more successful in this reach of the canal. Habitat such as temperature, turbidity, and water flow, may also be a reason for the increased larval abundance.

Catfish stockings appear to be helping to control the abundance of caddisflies. Substrate data showed much lower abundances where catfish have been stocked (near Scottsdale) than areas where no stockings occur (below SGL). In addition, sticky card data shows a much less severe hatch in 2012 than in previous years. Catfish stomach analysis indicates that they are eating aquatic insects, especially caddisflies and aquatic moths, when readily available.

Despite the relative success of the catfish stockings, there are concerns with continuation of the stocking program. For example, relative weights (condition) of the fish decreases substantially during winter and early spring when there is limited food availability. When relative weight is below 85, the fish are underweight and it indicates that fish are too abundant for the food supply. Although the mark/recapture data shows that some catfish are staying in the areas in which they are stocked, it is unknown how much movement may occur within a pool. The simple fin clips that were used do not identify individual fish and original stocking locations could not be determined because unique clips were not used. More precise data (e.g. acoustic tracking) is necessary to better determine catfish movement patterns.

Channel catfish stocked into the CAP


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E. Water Quality Introduction Water quality drives most biological process occurring in the canal. An effective monitoring program provides accurate data that can be used to answer biological questions, provide the basis for management decisions, and provide valuable information to our customers. Data collected in the past includes:

• Real-time data from water quality meters and turbidimeters permanently installed in MWP, HSY, and WAD - uploaded to the internet;

• Weekly monitoring using water quality meters at two stations – WAD and 7th Street Bridge (primarily for blue-green algae);

• Onset remote temperature loggers at MWP, BSH, 99th Ave, and Check 22; and • Monthly/quarterly water quality sampling at pumping plants, recharge facilities,

and Lake Pleasant (collected since 1989 by Water Operations). Methods Because maintenance (calibration) of the water quality sensors and turbidity meters at MWP, HSY, and WAD was difficult and sometimes resulted in inaccurate data, they were removed from each of the locations. The turbidity meter at Mark Wilmer remained in place to provide turbidity data for source water. A new sensor with advanced technology was purchased to be installed near the fish holding facility at CAP Headquarters. Data from this meter is automatically updated on the internet for use by our customers. The new water quality meter is scheduled to be installed in 2013. Weekly water quality monitoring using a Hydrolab DS-5 water quality meter continued throughout 2012. Measurements were taken weekly at the 7th St. Bridge, while weekly samples were only taken at WAD when water was being released from Lake Pleasant. The DS-5 measures temperature, conductivity, pH, dissolved oxygen, chlorophyll, salinity, and blue-green algae. In 2012, Onset Tidbit temperature loggers were re-deployed at MWP, BSH, 99th Ave., and Check 22, while new loggers were deployed at SGL, PIC, and SXV. Loggers were deployed in January and downloaded in December. Water Operations continued monthly monitoring of water quality at MWP, LHQ, 99th Ave., McKellips, BRD, and SXV. Twenty-four parameters are included in their monitoring program. Quarterly sampling of contaminants also continued at Havasu, LHQ, Lake Pleasant, 99th Ave., McKellips, BRD, and SXV. This sampling program includes 140 parameters. Results Due to the large amount of data collected, it will not be presented in this report. Water quality data is available upon request.


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F. Miscellaneous Several additional issues were addressed in 2012:

1. Diatoms In late May, CAP personnel received complaints from the City of Phoenix regarding blockage at the Phoenix Lake Pleasant Turnout. The general thought was that quagga mussels had infested the trash racks to a point where it was affecting flow into the turnout. Although there was no differential observed and the City of Phoenix did not show data indicating restricted flow, CAP deployed an ROV at the turnout to inspect the quagga infestation. Upon deployment of the ROV, CAP personnel observed that the trash racks at the turnout were severely restricted by an unknown organism. Samples and pictures were

collected and taken to the Arizona Game and Fish Department (AZGFD) water quality lab for further inspection. AZGFD identified the organism as a diatom (single-celled algae) known as Cymbella that is commonly found in Arizona. In August, a "cotton-like" substance was observed floating on the water surface downstream of Lake Pleasant and through Phoenix and Scottsdale. Samples were taken to a water testing lab in Tempe where the substance was also identified as the stalked diatom known as Cymbella or "rock snot".

Although the Cymbella is an invasive diatom species, it typically is not cause for concern in the canal. However, observations by CAP personnel suggest that abundance may be increasing. Heavy infestation of Cymbella has been known to clog intakes and cause differential at pumping plants and water treatment facilities. CAP will evaluate infestation in 2013 when using the ROV for inspections. This will help to determine if management actions are warranted. As a side note, the turnout at Lake Pleasant was found to be heavily infested with quagga mussels on the back side of the trash rack. Although the combination of Cymbella and quagga is not currently causing flow restrictions, the racks are scheduled to be cleaned at the next available opportunity.

2. Integrated Pest Management Plan (IPM) An IPM is an effective and environmentally sensitive approach to pest management that relies on a combination of common-sense practices. IPM programs use current, comprehensive information on the life cycles of pests and their interaction with the environment. This information, in combination with available pest control methods, is

Cymbella (Rock Snot) growing on the racks at the Phoenix Lake Pleasant Turnout


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used to manage pest damage by the most economical means, and with the least possible hazard to people, property, and the environment. In early 2012, the CAP Senior Biologist was asked by the Assistant General Manager of Maintenance to provide an update to CAP's 1999 IPM. A draft IPM was produced in March 2012 and updated in May and December 2012. The plan will be finalized in 2013; however, it is not meant to be a static document, and changes will be made when necessary.

3. Vegetation Control in Recharge Basins Growth of vegetation in CAP's recharge basin has caused a decline in the infiltration rates. The vegetation was identified in the past as chara (muskgrass), a multi-cellular algae species that looks like rooted vegetation. In response, CAP would drain the basins and use heavy equipment to remove the vegetation, and then rip the soil to restore filtration rates. This practice was time consuming and labor intensive. In early 2012, the Senior Biologist was asked by Water Systems to develop a plan to eliminate vegetation from CAP recharge basins. Arizona Department of Water Resources (ADWR) was consulted to allow the use of a copper-based product to treat the chara. In February, the use of copper to treat the vegetation was authorized with the stipulation that samples taken twice per year for groundwater monitoring would include analysis for copper, and that annual reporting would include an accounting of all chemicals used to control vegetation. A product known as Earthtec was chosen for control of vegetation in the recharge basins because it is self-dispersing (for efficient application), is ANSI/NSF 60 certified for drinking water application, and is effective on a variety of aquatic vegetation species. In May, Heiroglyphics Recharge Facility was scheduled to be treated with Earthtec for excessive growth of chara (Basins 1A, 1B, and 1C). However, just prior to treatment, a site visit revealed that the vegetation growth consisted primarily of sago pondweed, with only sparse amounts of chara. Basin 1C was still treated and monitored for the next two weeks to determine effectiveness of the 0.12 ppm Earthtec treatment. Results of the treatment were better than expected, with a partial kill over most of the area. In June, Earthtec was used to treat all three basins (1A, 1B, and 1C) for pondweed and chara growth. Application rates were increased to 0.6 ppm and the ponds were to be evaluated weekly for 30 days. However, one-week after treatment, Operations altered their plans for the basins and they were drained. During that week, the Earthtec had done a reasonably good job of killing vegetation. Further evaluation is needed, but it appears that Earthtec is a viable alternative for removing (killing) vegetation in the recharge basins.

4. Sediment Sediment deposition in the CAP can be detrimental to water delivery, as the capacity of the canal decreases with increased sedimentation and equipment is at risk for fouling. In the past, CAP has contracted with an outside vendor to collect data and produce high-resolution bathymetric (bottom contour) maps. These outside services are typically very expensive.


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The Lowrance HDS-7 Chartplotter that was purchased for weed mapping (see sections B and C above) can also be used to produce bathymetric maps. Results of the survey completed in the Lake Havasu intake channel in June 2012 were compared with a contracted bathymetric survey completed in 2011 and the maps matched up extremely well. Based on these results, work orders were generated to map the forebays of BSH and SGL to determine sediment deposition. These maps will then be used during sediment removal operations to target specific areas. BSH forebay was mapped in August (Figure 22) and SGL forebay was mapped in September (Figure 23). These pre-sediment removal maps will be followed-up by post-removal mapping to determine the success of the removal efforts.

Figure 22. Bathymetric map generated from sediment mapping activities at BSH in August, 2012.


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Figure 23. Bathymetric map generated from sediment mapping activities at SGL in September, 2012.


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G. Meetings Attended and Presentations CAP Technical Committee .................................................................................... January 2012

Colorado River Aquatic Biologists (CRAB) ........................................................... January 2012

Arizona-New Mexico Chapter of the American Fisheries Society ................... February 2012

Central Arizona Quagga Team .......................................... March, July, and November 2012

Western Aquatic Plant Management Society ........................................................... April 2012

LCR Aquatic Nuisance Task Force* ................................................. May and November 2012 Presentation: 2011 CAP Quagga Mussel Monitoring and Research (May) Presentation: 2011 Lake Havasu Aquatic Plant Monitoring Report (May) Presentation: Use of Sonar to Map Aquatic Weeds in Lake Havasu (November)

Bill Williams Steering Committee ...................................................................................May 2012

CAP Kids Day .................................................................................................................. June 2012 Presentation: Biology at CAP Interagency Quagga Mussel Team ........................................... August and December 2012 Presentation: CAP Quagga Mussel Monitoring and Research (August)

LCR MSCP Planning Committee ........................................................................... October 2012

LCR Water Quality Partnership .......................................................................... November 2012

*Changed name to Colorado River Aquatic Invasive Species Task Force (CR-AISTF) in summer 2012

2012 annual report biology - central arizona project...2012 annual report - biology 2 table of...

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