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T21: Fisheries: Invasive Species II [clear filter]
Tuesday, January 29
 

3:20pm

(FISHERIES: INVASIVE SPECIES 2) Spawning Chronology and Environmental Factors Associated with Grass Carp Reproduction in the Sandusky River
AUTHORS: Nicole R. King, University of Toledo Lake Erie Center; Madeline G. Tomczak, University of Toledo; Patrick M. Kocovsky, US Geological Survey; Christine M. Mayer, University of Toledo Lake Erie Center; Song S. Qian, University of Toledo Lake Erie Center

ABSTRACT: Invasive grass carp have been documented in the Great Lakes since 1975. Although occasional individuals have been captured, it was assumed that most were sterile escapees from stocked ponds. However, spawning was documented in the Great Lakes in 2015 with the collection of eight eggs from the Sandusky River, Ohio, a Lake Erie tributary. In 2016 no eggs were found despite extensive effort, likely because no high discharge events occurred, and grass carp, like some other non-native carps, spawn during high flows. Monitoring continued in 2017 with increased sampling effort including the addition of a second net and adaptive sampling after egg detection to follow the spatial extent of the egg mass. In 2017 the Sandusky River yielded 7,000+ eggs during two high flow events. The earliest developmental stage, three (stage one= no cell division, thirty= hatch) occurred at the most upstream site and the latest developmental stage (twenty five) near the river mouth. Egg stages were more variable at downstream sites and during lower flows; slower moving eggs are more likely to hatch in the river and survive to larvae. The pattern of egg stages and spatial distribution over time indicated spawning likely occurred several times or over a prolonged period. Although the hydrograph indicates that grass carp spawn during high flows, it is unknown what proximal cues initiate spawning and what specific conditions increase the likelihood of egg survival. We back calculated spawning time based on egg stage, collection location, and temperature to determine what specific factors may trigger spawning. Furthermore, we examined the conditions that likely support egg hatching and survival within the river. Preliminary analysis indicates several spawning bouts over a <10 hour time period. The ability to predict the timing and location of GC spawning and recruitment potential has implications for future control efforts.

Tuesday January 29, 2019 3:20pm - 3:40pm
HOPE BALLROOM C

3:40pm

(FISHERIES: INVASIVE SPECIES 2) Early Life History of Age-0 Silver Carp in the Mississippi River Basin
AUTHORS: Hae H. Kim, Quinton E. Phelps – West Virginia University Division of Forestry and Natural Resources; David Weyers, Sara J. Tripp – Missouri Department of Conservation Big Rivers Field Station.

ABSTRACT: Survival during early life history and recruitment adult structure population demographics. Numerous studies have demonstrated that riverine fishes are prone to variable early life survival and recruitment. High abundance of Silver Carp Hypophthalmichthys molitrix in the upper Mississippi River basin suggests great spawning and recruitment success. Previous studies have largely focused on characterizing adult Silver Carp populations. However, early life history has not been evaluated. Thus, we examined relative abundance, growth rates, hatch timing, and mortality of age-0 Silver Carp. We used data collected in mini-fyke nets by the Long Term Resource Monitoring element in three river upper Mississippi River reaches. A total of 154,092 age-0 Silver Carp were captured, ranging from 7.5-170 mm. Catch per unit effort ranged from 0-107 fish/net with an overall average of 11.86 (0.4) fish/net. Growth rates ranged from 0.74 – 1.81 mm/day with a total mean growth rate of 1.25 mm/d (0.03) mm/day. Daily mortality (z) ranged from 0.74-0.94 and averaged 0.832 (0.09). Silver Carp hatched within a 115-day window between 22 May and 15 September, with hatch peaking between 21 June and 19 July. Baseline demographic knowledge will aid managers control and limit Asian Carp spread throughout the Mississippi River Basin.

Tuesday January 29, 2019 3:40pm - 4:00pm
HOPE BALLROOM C

4:00pm

(FISHERIES: INVASIVE SPECIES 2) Potential Beneficial Effects of Invasive Silver Carp on Native Fishes
AUTHORS: Rebekah L. Anderson, Nathan J. Lederman – Aquatic Nuisance Species Program, Illinois Department of Natural Resources; Cory A. Anderson, U.S. Fish and Wildlife Service; Jason A. DeBoer, Illinois River Biological Station, Illinois Natural History Survey.

ABSTRACT: Substantial research attests to the injurious impacts invasive silver carp (Hypophthalmichthys molotrix) have on Midwestern U.S. river systems. Particularly, the dietary overlap between silver carp and native planktivores has resulted in declined condition and abundance of these species in areas where silver carp dominate the community (i.e., the lower Illinois River). However, additional research demonstrates silver carp may benefit native non-planktivorous fishes because of the carp’s ability to produce young at a large scale providing an abundant prey source for native piscivores, and their nutrient rich fecal pellets may enrich benthic forage quality for native benthivores. Potential positive effects of silver carp for native fishes are not fully understood, and research is limited in natural systems. Here we determine whether silver carp benefit non-planktivorous native fishes in the lower Illinois River (i.e., Peoria, LaGrange, and Alton pools) by examining native piscivore and benthivore body condition over time utilizing two standardized long-term data programs. We found a significant positive relationship between silver carp abundance and native benthivore body condition. Moreover, visual trends indicate increased body condition during and immediately after strong silver carp year classes (2008 & 2014) for both native piscivores and benthivores. Therefore density-dependent effects may exist where juvenile silver carp populations and benthic nutrient levels must reach a threshold before they are exploitable (i.e., beneficial) resources. We suggest more years of data that incorporate strong silver carp year classes may be needed to clarify potential positive effects of silver carp for native non-planktivorous fishes.

Tuesday January 29, 2019 4:00pm - 4:20pm
HOPE BALLROOM C

4:20pm

(CANCELLED) (FISHERIES: INVASIVE SPECIES 2) Demographics of Bigheaded Carp in the Illinois River, IL
AUTHORS: Jeremy Hammen*, U.S. Fish & Wildlife Service, Columbia Fish & Wildlife Conservation Office; Jahn Kallis, U.S. Fish & Wildlife Service, Columbia Fish & Wildlife Conservation Office; Emily Pherigo, U.S. Fish & Wildlife Service, Columbia Fish & Wildlife Conservation Office; Jason Goeckler, U.S. Fish & Wildlife Service, Columbia Fish & Wildlife Conservation Office

ABSTRACT: Effective fisheries management requires representative data that can be collected in an efficient, reasonable timeframe. This can be difficult for invasive species, like Bigheaded carp, where conventional methods can be limited in their ability to assess populations. Recent gear development and evaluation efforts have provided crucial information on the advancements in sampling methods and tools for Bigheaded carp. Information gained from these studies could be used to give managers and researchers the ability to appropriately assess these Bigheaded carp populations over a temporal and spatial scale. A pool-wide Bigheaded carp monitoring design using one of these novel gears, the electrified dozer trawl, was developed to evaluate the population characteristic differences throughout the Illinois River. Preliminary (first year) results demonstrated that population demographics at the pool level differed throughout the Illinois River. Relative abundance and size structure change throughout the Illinois River and small fish (< 200mm) were absent from the upper two pools. Additionally, it appears that habitats (main channel border, side channel, backwater) may differ in Bigheaded carp demographics but results after the first year were not significant likely due to small sample size. Estimated sample sizes based on minimizing variation in relative abundance and size structure appear to be representative through one year. Early results suggests that management of Bigheaded carp in the Illinois River may be different from pool to pool. Additionally, further refinement of the sampling efforts may be possible (i.e., smaller sample size) to make monitoring these populations more efficient and effective. Maintaining successful management activities for Bigheaded carp will require cost-effective sampling efforts in a representative and effective matter. This work will benefit those management efforts in the Illinois River and this study could provide the framework to expand throughout their Mississippi River basin where Bigheaded carp are located.

Tuesday January 29, 2019 4:20pm - 4:40pm
HOPE BALLROOM C