Difference between revisions of "Green Sunfish Page"
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==2016== | ==2016== | ||
− | + | (10/24/16) The ammonia treatment to eradicate green sunfish from the isolated pond at river mile -12 in Glen Canyon began at approximately noon on Thursday October 20, 2016 when crews applied 20 gallons of ammonia to the pond. Dead and dying green sunfish were observed within about 90 minutes. To help confirm the effectiveness of the treatment, 14 cages with from 3 to 20 sentinel green sunfish each were placed in locations throughout the pond. Crews checked the pond at 1430 hours and observed dead green sunfish on the bottom of the pond and in the sentinel cages although not all the sentinel fish were dead. Crews returned to the pond the morning of Friday October 21, 2016 and found that all the sentinel green sunfish were dead. They also counted 939 dead juvenile green sunfish as well as 10 dead carp, 7 adults and 3 juveniles. The crews electrofished the pond and collected 3 live juvenile green sunfish and 1 live juvenile carp from one small area near the upstream end of the pond where a small amount of water was flowing into the pond. These fish appeared to have been affected by the ammonia, but hadn’t yet succumbed unlike other dead green sunfish observed in this same small area. The captured green sunfish were sacrificed and crews poured in one gallon of ammonia to spot treat this area to ensure any other remaining fish would be killed. No other live fish were observed. Ammonia levels in the pond will remain at levels lethal to green sunfish for 7 to 14 days, thus we are confident that the treatment will eradicate green sunfish from this site. Another electrofishing survey is scheduled for Tuesday October 25, 2016 to confirm green sunfish have been eliminated from the pond. Surveys for green sunfish at two other locations in Glen Canyon that might be suitable for rearing of young fish were also conducted this week. Two baited minnow traps were set at “frog marsh” at rive mile -8 and four baited minnow traps at the hidden slough at rive mile -6.5 on Wednesday October 19, 2016. The traps were retrieved after 24 hours and no fish were captured. <br> --Scott VanderKooi, GCMRC | |
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− | The ammonia treatment to eradicate green sunfish from the isolated pond at river mile -12 in Glen Canyon began at approximately noon on Thursday October 20, 2016 when crews applied 20 gallons of ammonia to the pond. Dead and dying green sunfish were observed within about 90 minutes. To help confirm the effectiveness of the treatment, 14 cages with from 3 to 20 sentinel green sunfish each were placed in locations throughout the pond. Crews checked the pond at 1430 hours and observed dead green sunfish on the bottom of the pond and in the sentinel cages although not all the sentinel fish were dead. Crews returned to the pond the morning of Friday October 21, 2016 and found that all the sentinel green sunfish were dead. They also counted 939 dead juvenile green sunfish as well as 10 dead carp, 7 adults and 3 juveniles. The crews electrofished the pond and collected 3 live juvenile green sunfish and 1 live juvenile carp from one small area near the upstream end of the pond where a small amount of water was flowing into the pond. These fish appeared to have been affected by the ammonia, but hadn’t yet succumbed unlike other dead green sunfish observed in this same small area. The captured green sunfish were sacrificed and crews poured in one gallon of ammonia to spot treat this area to ensure any other remaining fish would be killed. No other live fish were observed. Ammonia levels in the pond will remain at levels lethal to green sunfish for 7 to 14 days, thus we are confident that the treatment will eradicate green sunfish from this site. Another electrofishing survey is scheduled for Tuesday October 25, 2016 to confirm green sunfish have been eliminated from the pond. Surveys for green sunfish at two other locations in Glen Canyon that might be suitable for rearing of young fish were also conducted this week. Two baited minnow traps were set at “frog marsh” at rive mile -8 and four baited minnow traps at the hidden slough at rive mile -6.5 on Wednesday October 19, 2016. The traps were retrieved after 24 hours and no fish were captured. | + | |
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− | Scott VanderKooi, GCMRC | + | |
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'''Sampling results from September 1-2, 2016 <br>''' | '''Sampling results from September 1-2, 2016 <br>''' | ||
− | - 822 | + | - 822 green sunfish total (806 in the upper slough, 16 in the lower); three YOY (young-of-year) size classes + adults <br> |
− | - 22 | + | - 22 carp total (21 in upper, 1 in lower) <br> |
- 7 larval salamanders (all upper) <br> | - 7 larval salamanders (all upper) <br> | ||
− | - 3 | + | - 3 rainbow trout (all lower) <br> |
- temperature in upper slough- 20.7 C (9/1) <br> | - temperature in upper slough- 20.7 C (9/1) <br> | ||
- temperature in lower slough- 16.7 C (9/1, upper portion) <br> | - temperature in lower slough- 16.7 C (9/1, upper portion) <br> | ||
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*[http://youtu.be/dq3yvvEjsOo| Demo video that shows how to do an ammonia treatment to remove invasive aquatic species] | *[http://youtu.be/dq3yvvEjsOo| Demo video that shows how to do an ammonia treatment to remove invasive aquatic species] | ||
*[http://gcdamp.com/index.php?title=The_HFE_Page The High Flow Experiment (HFE) Page] | *[http://gcdamp.com/index.php?title=The_HFE_Page The High Flow Experiment (HFE) Page] | ||
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+ | ! <h2 style="margin:0; background:#cedff2; font-size:120%; font-weight:bold; border:1px solid #a3b0bf; text-align:left; color:#000; padding:0.2em 0.4em;"> Non-Native Fish EA </h2> | ||
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+ | Update: 5/23/2017 <br> EA will address a permanent solution and will include green sunfish and brown trout in the Lees Ferry reach. Public review process is starting and there will be a public scoping meeting in June. Draft EA by early 2018. Leads: NPS (GCNRA and GCNP). Cooperating Agencies: | ||
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+ | The NPS is hosting a webinar on October 27, 2016 for stakeholders and interested parties to develop a range of options for '''Long Term Risk Reduction for Green Sunfish in the -12 RM sloughs''', and other invasive fish species and locations in the Lees Ferry Reach of Glen Canyon National Recreation Area. This 'brainstorming' session will provide the basis for developing a range of alternatives to be analyzed in a Long Term Risk Reduction Plan and Environmental Assessment to be completed and implemented by October 2017. For more information contact Melissa Trammell at [email protected] | ||
+ | *[[Media:Glen Canyon Sloughs & Green Sunfish Control Email Version.pdf| Monitoring and Management of Non-native Fish in Glen Canyon NRA and Grand Canyon NP, October 2016 Workshop]] | ||
+ | *[[Media:Lees Ferry pre scoping.pdf| Scoping for an NPS Environmental Assessment for a Long Term Risk Reduction Plan for Invasive Nonnative Fish in Glen Canyon NRA and Grand Canyon NP]] | ||
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Revision as of 11:32, 31 May 2017
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Green Sunfish (Lepomis cyanellus)Description: Native to the Great Lakes, Hudson Bay and the Mississippi River basin. Introduced into Arizona in 1926. Large mouth with blue-green striations on the cheeks. Opercle flap is black with reddish or orange border. Bodies olive-green in color, dark vertical bars are faintly seen on sides. Pectoral fin short and rounded. Caudal fin and lower fin margins are white or yellowish with dusky spots at rear of dorsal and anal fins. Length: 3 to 12 inches. Weight: 3 ounces to 1 pound 8 ounces. May live to nine years. Location and Habitat: Found in most seasonally warm water lakes and streams in Arizona. Prefer lakes with rocky substrate and piles of rubble, but can be found in slow moving rivers and riverine backwaters. Green sunfish have been found at a wide range of stream gradients, varying from 0.2 to 5.7 m/km; however, they are most abundant at lower (<2 m/km) gradients. They prefer small to medium-sized (<30 m width) streams.[1] Being native to the Great Lakes and Mississippi River Basin, green sunfish are well suited to tolerate long periods of cold water. Temperature: Being native to the Great Lakes and Mississippi River Basin, green sunfish are well suited to tolerate long periods of cold water. The summertime temperature preference for adult green sunfish is 28.2° C and, when possible, they avoid temperatures above 31° C or below 26° C. Growth and food conversion efficiency increase as temperature increases from 13.2 to 28° C. Optimal temperatures for fry range from 18 to 26° C. The range of tolerance for bluegill fry is 10 to 36° C, and it is assumed that green sunfish fry tolerances are similar. Temperature requirements for juveniles are assumed to be the same as those for adults.[2] 2015-2016 temperatures in the mainstem ranged from 8.0-15.5 C between Lees Ferry and the Little Colorado River. 2015-2016 temperatures in the Little Colorado River ranged from 10.0-28.0 C and are within the temperature tolerances of green sunfish spawning and growth. Turbidity and Dissolved Oxygen: Green sunfish tolerate greater turbidity and lower dissolved oxygen than other sunfish.[3] Moderate (25-100 JTU) turbidities correlated with high species abundance are optimum.[4] Ventilation rates were not affected by bentonite clay suspensions below 2,125 FTU at 5 C, 1,012 FTU at 15 C, and 898 FTU at 25 C. At turbidity levels exceeding 1,012 FTU at 15 C and 898 FTU at 25 C ventilation rates increased 50-70%. Oxygen consumption rates were not affected by turbid suspensions of up to 3,500 FTU at any of the four temperatures.[5] Salinity: Green sunfish have preferred salinity tolerances <0.36% and will not tolerate salinity >0.56%.[6] The Little Colorado River has a naturally high salinity at baseflow ranging from 0.22% - 0.36%.[7] Reproduction: Optimal temperature for spawning and subsequent development ranges from 20 to 27° C. Spawning will not occur below 19° C or above 31° C.[8] Males build nests in shallow pools over gravel, sand or bedrock. The nests are usually within a couple feet of each other. The male guards the nest and hatched fry. Males constantly show defensive displays and fight with other males who come too close. It is thought that green sunfish may produce the same number of eggs as bluegill, which is roughly 50,000 eggs per female. It takes normally 1 to 2 days for the eggs to hatch and another 5 to 7 days of protection from the male until the fry become independent. Green sunfish can spawn up to every 8 to 10 days during the spawning season.[9] Food: Green sunfish will eat anything they can catch and swallow. Aquatic and terrestrial insects and invertebrates are the most common food items. Small crayfish, humpback chub, and frogs are all in danger when green sunfish are present. Young life stages of chub do not persist in streams occupied by Green Sunfish. No recruitment of young-of-year Gila Chub (Gila intermedia) occurred in the presence of sunfish in Sabino Creek, Arizona (Dudley and Matter, 2000). Risk: Green sunfish may temporarily be displaced into colder more unfavorable environments where survival might be lower, but the fish that do survive will seek out warm backwaters and tributaries after moving downstream. An upstream source that continues to allow new individuals to disperse downstream and colonize tributaries, when they are not in flood stage, greatly increases the likelihood of sunfish establishment in tributaries of the CRe. If no action is taken, there is a high risk of sunfish spreading downstream and becoming established in and near other tributaries, primarily the Little Colorado River, where negative impacts to the endangered humpback chub will occur. (Green Sunfish Risk Assessment) |
Online training |
Fish Species of the Colorado River in Lower Glen Canyon and Grand Canyon |
Fish photos, information, and maps |
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