ARIZONA BASS NATION
Conservation Alert
Don McDowell
Conservation Director
17-Apr-13
The growing concern of the effects of Gizzard Shad on Roosevelt Lake has spawn how to fix the problem opinions, rumors, complaints, claim of dropping Tonto Basin property values, decreasing winter visitors fishing the lake and claims that major tournament circuits may be passing Roosevelt Lake in the future.
One such rumor which has no foundation is to implement stocking of hybrid stripper to prey upon the Gizzard Shad according to Fisheries Branch Chief Chris Cantrell the rumor is not true saying that:
1. The cost effectiveness of this action would not make it worth it. It would take hundreds of thousands of striped bass to have an effect.
2. The environmental impact from this would be unknown. It could have an even worse effect to our bass and crappie populations.
3. SRP and APS (Reclamation) are spending millions of dollars to keep striped bass out of the salt system. This would be a political nightmare.
The following items may provide solid information to anglers to formulate an opinion and engaged in the process with Fisheries Branch Chief Cantrell to engage the AZGFD into further action plans to deal with the effects of the Gizzard Shad in Roosevelt. After digesting the following information, please forward you comments to CCantrell@AZFGD.gov in a meaningful manner.
1. Friday, 19th-Apr-2013 a Town Hall Round Table type meeting is being held in Punkin Center to explore options, take suggestion and a firm call for action from local residents from Payson, Tonto Basin, and other community in the Roosevelt Region of Gila County. The agenda is provided below, the public is welcome to attend the Round Table meeting and engage in dialogue on the varying aspects of Gizzard Shad issues:
6:00 - 6:10 Introductions/ Welcome James Goughnour
6:10 – 6:15 Concern Statement James Goughnour
6:15 – 6:25 Commissioner Madden Perspective Pat Madden
6:15 – 6:35 Director Riley Perspective Larry Riley
6:35 – 7:00 Open Forum
There is a growing concern that the catch rates and size of fish in Roosevelt Lake is having an ever expanding impact on the fishery as well as an economic impact Tonto Basin and surrounding communities. Attracting tournament and recreational anglers to Roosevelt Lake has been a life line for many businesses in this area for many years. If Roosevelt Lake can’t provide and enjoyable fishing experience for tournaments, winter visitors and recreational anglers they will simply go elsewhere. Several long time winter visitors that come to Gila County to spend the winter and fish Roosevelt Lake have stated they will not be returning next year, opting to fish in the state of Texas. Local businesses have reported lower sales and reservations in the past year. If this trend continues and a “wait and see” attitude taken this problem could significantly impact the fishery as well as many in the communities.
Over the past several years, the number of crappie being caught has reduced dramatically. Crappie Fishing Guides who make a living taking customers crappie fishing and local anglers that fish more than three times per week are reporting on average 4-5 crappie per day compared with 20+ crappie being caught just a few years ago. During the 2011 FLW Everstart tournament 92% of the pro anglers weighed a limit of bass during the tournament. The total combined weight of the top 10 finishers in that tournament had a total weight of over 350lbs. In the most recent Everstart held two months ago 13% of the pros brought a limit to the scales over the three days with a total weight of 200 lbs. In addition, the winner of the tournament only weighed 10 fish for three days of fishing. Similar results have been seen at the WON tournaments as well as several local tournaments held on Roosevelt Lake. A few years ago, Roosevelt Lake was named by BASS Magazine as one of the top 100 bass fishing lakes in the country. However, that has changed in the past couple of years and we are now struggling to convince anglers and tournaments to come to Roosevelt Lake.
The FLW broadcasts live weigh-ins over the internet which is viewed by half a million viewers according to the FLW. In addition the FLW website is visited by a million people each week. The FLW Tournament Director noted the lower number and sizes during the most recent tournament. With that kind of publicity, it doesn’t take long for potential visitors to select another lake for their vacation or tournament.
AZGFD Fishery Branch Manager Chris Cantrell wrote an article a few months ago for Western Outdoor Times Magazine where he expressed a deep and real concern about the rapidly increasing number of gizzard shad and the corresponding drop in conditions of bass and bluegill. His report detailed findings from 2008-2011. During the most recent shock program in 2011 27.7% of the fish shocked were gizzard shad. In addition and perhaps more concerning is the rapid growth of the gizzard shad has resulted gizzard shad being too large for the bass to consume as forage.
According to Chris Cantrell, AZGFD does not target crappie in their shocking program since they are more of a deeper water fish which makes it harder to collect data. However, with the dramatic reduction in numbers and condition of bluegill may also relate to crappie as well. Gizzard shad feed on zooplankton which is the main food source for bluegill, crappie and bass fry. In addition, Gizzard shad, bluegill and crappie all spawn at the same time which increases the competition for the zooplankton. So the AZGFD data supports what anglers have been reporting for the past few years. The steady decline in bass and crappie populations has been happening over the years and beyond the timeframe for this to be considered a natural cyclic event or a short term condition. Also in 2011, AZGFD confirmed the presence of gizzard shad in Apache Lake. So we can assume that whatever fate Roosevelt Lake as a fishery, and whatever economic impact is seen in the Roosevelt Lake local area will eventually be experienced by all lakes and communities on the Salt River chain.
Several opinions for possible solutions have been brought forward including artificial cover such as reel balls, more research, restocking the bass population or finding a fish that is a natural predator of gizzard shad. Perhaps the solution is all of the above or some combination. However, failure to take action related to the recent introduction of gizzard shad into Roosevelt Lake, which is causing a major impact to the fishery environment is not an option. We are asking that the AZGFD recognize there is a decrease in the sport fish in Roosevelt Lake and understand that it is having an effect on the local economy. We encourage you to fund a 2013 data collection shocking program on Roosevelt Lake and to allocate whatever additional funding is needed to determine the cause and implement of a solution.
2. As published by Fisheries Branch Chief Chris Cantrell as a result of continued studying, surveys and monitoring at Roosevelt, he reports the following in “Understanding the effects of Gizzard Shad in Roosevelt Lake”
Roosevelt Lake is the upper most and largest in a series of four reservoirs on the Salt River. The Bureau of Reclamation constructed Roosevelt Dam in 1911 forming Roosevelt Lake. At full capacity it is approximately 22 miles long with 91 miles of shoreline; its maximum depth is over 300 feet and it can store 1,653,043 acre feet of water. Roosevelt Lake is also home to a variety of game fish including largemouth and smallmouth bass, black crappie, yellow bass, bluegill, channel and flathead catfish and carp. Threadfin shad, gizzard shad, and bluegill are the predominant forage fish.
The land around Roosevelt Lake is managed by the U.S. Forest Service, more specifically the Tonto National Forest. The aquatic species within the lake come under the authority of Arizona Game and Fish Department (Department). As the Region VI Fisheries Program Manger, I have had the pleasure to manage Roosevelt Lake for the Department since 2009. One of the Department’s sportfish management objectives are to provide a diversity of sportfish to anglers, however, no management plan is currently developed for Roosevelt Lake.
Roosevelt Lake is estimated to experience over 98,000 angler use days per year and is also considered to be one of the top bass fishing lakes in Western North America. For this reason, Roosevelt Lake is a popular tournament lake, holding multiple bass fishing tournaments every week for most of the year. Over the past 30 years, Roosevelt Lake has experienced numerous social, political, and biological changes.
In October 2011, my program once again extensively surveyed Roosevelt Lake. This was part of a reoccurring study to monitor and evaluate the fishery and fish community structure and to detect changes over time in the fish community with priorities set for largemouth bass and gizzard shad. Priorities were set on largemouth bass due to the popularity of recreational angling for this species and for Gizzard shad due to their recent inhabitance in the Roosevelt Lake. The information obtained provides my program with data to aid in the development of recommendations to protect and improve the sport fishery of Roosevelt Lake and provide the baseline for the development of a management plan for Roosevelt Lake.
The findings of this study were significant. In 2011, gizzard shad made up the highest percentage of fish captured during the survey comprising 27.7% of the catch. As relatively new inhabitants of Roosevelt Lake, gizzard shad are flourishing. Their numbers have quickly grown over the last few years to become the most prevalent species (Figure 1) in the lake. Comparing Gizzard shad population size structure from 2008, 2009, and 2011, data visually indicates a shift in gizzard shad population structure from one population primarily dominated by fish in the 7-12in total length to one where the majority of the population is comprised of fish that are 13in total length and greater (Figure 2). The data suggests one of two possible scenarios: either there was either a really poor year class in 2010 or predators are finally starting to utilize gizzard shad as a prey base.
The effects of gizzard shad in Roosevelt Lake, though not fully understood, are now becoming evident. Gizzard shad are documented as having an impact on sport fisheries back east through competition with other forage and game species at the larval stage and a reduction as a food resource for largemouth bass as they soon outgrow largemouth bass mouth gapes. A fish researcher in the southeast developed an index used to determine the availability of gizzard shad as prey for largemouth bass in a body of water. His research designates 8 inches, was on average the upper limit for gizzard shad to be available as prey for an average sized (16 in), largemouth bass. Our data indicates 95% of the gizzard shad in Roosevelt Lake are too large o eat for the average largemouth bass. Comparing rates of prey vulnerability in Roosevelt Lake from 2008, 2009, and 2011, we show a decline from 34 to 24 to 5, which mimics the shift in size structure to a population dominated by large, 8in gizzard shad.
So what does this mean to the fisherman? Additional data collected indicated a severe lack of preferred and trophy sized bluegill in all years surveyed and a notable decline in the body condition of bluegill (Figure 3). This could be a cause and effect relationship due to the introduction of gizzard shad. Bluegill and gizzard shad spawning events are dependent on temperature and both peak between 66-71oF. If gizzard shad appear first depleting the zooplankton densities bluegill suffer reduced growth. Couple this with the fact that gizzard shad are providing little prey for largemouth bass and this may cause bass to feed more heavily on bluegill, thereby reducing the larger size classes in the population. Additionally, documented bluegill weights show a significant decrease since 2008 (Figure 4). This is most likely cause by direct food source competition with gizzard shad.
Similar to the bluegill, largemouth bass have shown a significant decline in relative weights in Roosevelt Lake (Figure 5). This weight decline corroborates reports from tournament anglers stating that overall bag weights have declined over the past few years. This decline in body condition may be a result of poor levels of prey availability of gizzard shad in combination with the lack of habitat structure in the lake. Roosevelt Lake is known to be limited in habitat as it contains very little aquatic vegetation, cover, and structure; the essentials of good fish habitat. This is indicative of many of our desert reservoirs in Arizona, as they have steep slopes to deep water and spring/summer water level declines reducing the ability for submersed aquatic vegetation to become establish. This limits cover to areas where large woody debris and rocky edge structure exist. In lakes void of diverse habitats, largemouth bass find their prey by searching, pursuing, and following, all of which a bass must do more of to obtain a meal in habitat limited waters. The more energy it takes a fish to find a meal; the slower they grow. Providing habitat structure in Roosevelt Lake may assist in providing more bass a concentrated prey base and the opportunity to ambush and attack prey more efficiently which in turn should result in increasing fatter, larger bass.
Although the effects of gizzard shad on sportfish and zooplankton have been studied extensively, most of the work has been done in the Midwest and East; poor equivalents to Arizona’s arid climates. Additionally, little data exist on the interactions between gizzard shad and forage species important to bass and their effects to game fish in Roosevelt and Apache Lake. In spring of 2012, gizzard shad were detected in Apache Lake for the first time. What is now needed is an intensive research project studying the effects of introduced gizzard shad on game fish species in Roosevelt and Apache Lake. Information gained through this research will be invaluable to future management of Arizona fisheries. Only by understanding and prioritizing these factors can we begin to proactively manage toward continued success of fisheries in Arizona.
By Chris Cantrell, Region VI Fisheries Program Manager, Arizona Game and Fish Department
Stay tuned for results and action form the Punkin Center Town Hall Round Table Meeting over the next week or so.
Conservation Alert
Don McDowell
Conservation Director
17-Apr-13
The growing concern of the effects of Gizzard Shad on Roosevelt Lake has spawn how to fix the problem opinions, rumors, complaints, claim of dropping Tonto Basin property values, decreasing winter visitors fishing the lake and claims that major tournament circuits may be passing Roosevelt Lake in the future.
One such rumor which has no foundation is to implement stocking of hybrid stripper to prey upon the Gizzard Shad according to Fisheries Branch Chief Chris Cantrell the rumor is not true saying that:
1. The cost effectiveness of this action would not make it worth it. It would take hundreds of thousands of striped bass to have an effect.
2. The environmental impact from this would be unknown. It could have an even worse effect to our bass and crappie populations.
3. SRP and APS (Reclamation) are spending millions of dollars to keep striped bass out of the salt system. This would be a political nightmare.
The following items may provide solid information to anglers to formulate an opinion and engaged in the process with Fisheries Branch Chief Cantrell to engage the AZGFD into further action plans to deal with the effects of the Gizzard Shad in Roosevelt. After digesting the following information, please forward you comments to CCantrell@AZFGD.gov in a meaningful manner.
1. Friday, 19th-Apr-2013 a Town Hall Round Table type meeting is being held in Punkin Center to explore options, take suggestion and a firm call for action from local residents from Payson, Tonto Basin, and other community in the Roosevelt Region of Gila County. The agenda is provided below, the public is welcome to attend the Round Table meeting and engage in dialogue on the varying aspects of Gizzard Shad issues:
TONTO BASIN ANGLERS ROUNDTABLE DRAFT AGENDA
6:00 - 6:10 Introductions/ Welcome James Goughnour
6:10 – 6:15 Concern Statement James Goughnour
6:15 – 6:25 Commissioner Madden Perspective Pat Madden
6:15 – 6:35 Director Riley Perspective Larry Riley
6:35 – 7:00 Open Forum
There is a growing concern that the catch rates and size of fish in Roosevelt Lake is having an ever expanding impact on the fishery as well as an economic impact Tonto Basin and surrounding communities. Attracting tournament and recreational anglers to Roosevelt Lake has been a life line for many businesses in this area for many years. If Roosevelt Lake can’t provide and enjoyable fishing experience for tournaments, winter visitors and recreational anglers they will simply go elsewhere. Several long time winter visitors that come to Gila County to spend the winter and fish Roosevelt Lake have stated they will not be returning next year, opting to fish in the state of Texas. Local businesses have reported lower sales and reservations in the past year. If this trend continues and a “wait and see” attitude taken this problem could significantly impact the fishery as well as many in the communities.
Over the past several years, the number of crappie being caught has reduced dramatically. Crappie Fishing Guides who make a living taking customers crappie fishing and local anglers that fish more than three times per week are reporting on average 4-5 crappie per day compared with 20+ crappie being caught just a few years ago. During the 2011 FLW Everstart tournament 92% of the pro anglers weighed a limit of bass during the tournament. The total combined weight of the top 10 finishers in that tournament had a total weight of over 350lbs. In the most recent Everstart held two months ago 13% of the pros brought a limit to the scales over the three days with a total weight of 200 lbs. In addition, the winner of the tournament only weighed 10 fish for three days of fishing. Similar results have been seen at the WON tournaments as well as several local tournaments held on Roosevelt Lake. A few years ago, Roosevelt Lake was named by BASS Magazine as one of the top 100 bass fishing lakes in the country. However, that has changed in the past couple of years and we are now struggling to convince anglers and tournaments to come to Roosevelt Lake.
The FLW broadcasts live weigh-ins over the internet which is viewed by half a million viewers according to the FLW. In addition the FLW website is visited by a million people each week. The FLW Tournament Director noted the lower number and sizes during the most recent tournament. With that kind of publicity, it doesn’t take long for potential visitors to select another lake for their vacation or tournament.
AZGFD Fishery Branch Manager Chris Cantrell wrote an article a few months ago for Western Outdoor Times Magazine where he expressed a deep and real concern about the rapidly increasing number of gizzard shad and the corresponding drop in conditions of bass and bluegill. His report detailed findings from 2008-2011. During the most recent shock program in 2011 27.7% of the fish shocked were gizzard shad. In addition and perhaps more concerning is the rapid growth of the gizzard shad has resulted gizzard shad being too large for the bass to consume as forage.
According to Chris Cantrell, AZGFD does not target crappie in their shocking program since they are more of a deeper water fish which makes it harder to collect data. However, with the dramatic reduction in numbers and condition of bluegill may also relate to crappie as well. Gizzard shad feed on zooplankton which is the main food source for bluegill, crappie and bass fry. In addition, Gizzard shad, bluegill and crappie all spawn at the same time which increases the competition for the zooplankton. So the AZGFD data supports what anglers have been reporting for the past few years. The steady decline in bass and crappie populations has been happening over the years and beyond the timeframe for this to be considered a natural cyclic event or a short term condition. Also in 2011, AZGFD confirmed the presence of gizzard shad in Apache Lake. So we can assume that whatever fate Roosevelt Lake as a fishery, and whatever economic impact is seen in the Roosevelt Lake local area will eventually be experienced by all lakes and communities on the Salt River chain.
Several opinions for possible solutions have been brought forward including artificial cover such as reel balls, more research, restocking the bass population or finding a fish that is a natural predator of gizzard shad. Perhaps the solution is all of the above or some combination. However, failure to take action related to the recent introduction of gizzard shad into Roosevelt Lake, which is causing a major impact to the fishery environment is not an option. We are asking that the AZGFD recognize there is a decrease in the sport fish in Roosevelt Lake and understand that it is having an effect on the local economy. We encourage you to fund a 2013 data collection shocking program on Roosevelt Lake and to allocate whatever additional funding is needed to determine the cause and implement of a solution.
2. As published by Fisheries Branch Chief Chris Cantrell as a result of continued studying, surveys and monitoring at Roosevelt, he reports the following in “Understanding the effects of Gizzard Shad in Roosevelt Lake”
Roosevelt Lake is the upper most and largest in a series of four reservoirs on the Salt River. The Bureau of Reclamation constructed Roosevelt Dam in 1911 forming Roosevelt Lake. At full capacity it is approximately 22 miles long with 91 miles of shoreline; its maximum depth is over 300 feet and it can store 1,653,043 acre feet of water. Roosevelt Lake is also home to a variety of game fish including largemouth and smallmouth bass, black crappie, yellow bass, bluegill, channel and flathead catfish and carp. Threadfin shad, gizzard shad, and bluegill are the predominant forage fish.
The land around Roosevelt Lake is managed by the U.S. Forest Service, more specifically the Tonto National Forest. The aquatic species within the lake come under the authority of Arizona Game and Fish Department (Department). As the Region VI Fisheries Program Manger, I have had the pleasure to manage Roosevelt Lake for the Department since 2009. One of the Department’s sportfish management objectives are to provide a diversity of sportfish to anglers, however, no management plan is currently developed for Roosevelt Lake.
Roosevelt Lake is estimated to experience over 98,000 angler use days per year and is also considered to be one of the top bass fishing lakes in Western North America. For this reason, Roosevelt Lake is a popular tournament lake, holding multiple bass fishing tournaments every week for most of the year. Over the past 30 years, Roosevelt Lake has experienced numerous social, political, and biological changes.
In October 2011, my program once again extensively surveyed Roosevelt Lake. This was part of a reoccurring study to monitor and evaluate the fishery and fish community structure and to detect changes over time in the fish community with priorities set for largemouth bass and gizzard shad. Priorities were set on largemouth bass due to the popularity of recreational angling for this species and for Gizzard shad due to their recent inhabitance in the Roosevelt Lake. The information obtained provides my program with data to aid in the development of recommendations to protect and improve the sport fishery of Roosevelt Lake and provide the baseline for the development of a management plan for Roosevelt Lake.
The findings of this study were significant. In 2011, gizzard shad made up the highest percentage of fish captured during the survey comprising 27.7% of the catch. As relatively new inhabitants of Roosevelt Lake, gizzard shad are flourishing. Their numbers have quickly grown over the last few years to become the most prevalent species (Figure 1) in the lake. Comparing Gizzard shad population size structure from 2008, 2009, and 2011, data visually indicates a shift in gizzard shad population structure from one population primarily dominated by fish in the 7-12in total length to one where the majority of the population is comprised of fish that are 13in total length and greater (Figure 2). The data suggests one of two possible scenarios: either there was either a really poor year class in 2010 or predators are finally starting to utilize gizzard shad as a prey base.
The effects of gizzard shad in Roosevelt Lake, though not fully understood, are now becoming evident. Gizzard shad are documented as having an impact on sport fisheries back east through competition with other forage and game species at the larval stage and a reduction as a food resource for largemouth bass as they soon outgrow largemouth bass mouth gapes. A fish researcher in the southeast developed an index used to determine the availability of gizzard shad as prey for largemouth bass in a body of water. His research designates 8 inches, was on average the upper limit for gizzard shad to be available as prey for an average sized (16 in), largemouth bass. Our data indicates 95% of the gizzard shad in Roosevelt Lake are too large o eat for the average largemouth bass. Comparing rates of prey vulnerability in Roosevelt Lake from 2008, 2009, and 2011, we show a decline from 34 to 24 to 5, which mimics the shift in size structure to a population dominated by large, 8in gizzard shad.
So what does this mean to the fisherman? Additional data collected indicated a severe lack of preferred and trophy sized bluegill in all years surveyed and a notable decline in the body condition of bluegill (Figure 3). This could be a cause and effect relationship due to the introduction of gizzard shad. Bluegill and gizzard shad spawning events are dependent on temperature and both peak between 66-71oF. If gizzard shad appear first depleting the zooplankton densities bluegill suffer reduced growth. Couple this with the fact that gizzard shad are providing little prey for largemouth bass and this may cause bass to feed more heavily on bluegill, thereby reducing the larger size classes in the population. Additionally, documented bluegill weights show a significant decrease since 2008 (Figure 4). This is most likely cause by direct food source competition with gizzard shad.
Similar to the bluegill, largemouth bass have shown a significant decline in relative weights in Roosevelt Lake (Figure 5). This weight decline corroborates reports from tournament anglers stating that overall bag weights have declined over the past few years. This decline in body condition may be a result of poor levels of prey availability of gizzard shad in combination with the lack of habitat structure in the lake. Roosevelt Lake is known to be limited in habitat as it contains very little aquatic vegetation, cover, and structure; the essentials of good fish habitat. This is indicative of many of our desert reservoirs in Arizona, as they have steep slopes to deep water and spring/summer water level declines reducing the ability for submersed aquatic vegetation to become establish. This limits cover to areas where large woody debris and rocky edge structure exist. In lakes void of diverse habitats, largemouth bass find their prey by searching, pursuing, and following, all of which a bass must do more of to obtain a meal in habitat limited waters. The more energy it takes a fish to find a meal; the slower they grow. Providing habitat structure in Roosevelt Lake may assist in providing more bass a concentrated prey base and the opportunity to ambush and attack prey more efficiently which in turn should result in increasing fatter, larger bass.
Although the effects of gizzard shad on sportfish and zooplankton have been studied extensively, most of the work has been done in the Midwest and East; poor equivalents to Arizona’s arid climates. Additionally, little data exist on the interactions between gizzard shad and forage species important to bass and their effects to game fish in Roosevelt and Apache Lake. In spring of 2012, gizzard shad were detected in Apache Lake for the first time. What is now needed is an intensive research project studying the effects of introduced gizzard shad on game fish species in Roosevelt and Apache Lake. Information gained through this research will be invaluable to future management of Arizona fisheries. Only by understanding and prioritizing these factors can we begin to proactively manage toward continued success of fisheries in Arizona.
By Chris Cantrell, Region VI Fisheries Program Manager, Arizona Game and Fish Department
Stay tuned for results and action form the Punkin Center Town Hall Round Table Meeting over the next week or so.
