Shannon J. Fisher

Early Life History of Yellow Perch in Two South Dakota Glacial Lakes

ABSTRACT The early life history of yellow perch (Perca flavescens) was studied during 1995 and 1996 in two glacial lakes. Pelican Lake contained a yellow perch population with fast growth and desirable size structure, while Pickerel Lake contained a slow-growing yellow perch population dominated by individuals less than 20-cm TL. The first food of perch larvae in Pickerel Lake was copepod nauplii, with a switch to adult copepods by 7-mm total length (TL). However, in 1995, copepod nauplii density was low and larvae began feeding on adult copepods at a smaller length. The 1995 diets of Pelican Lake larvae were similar to those found in Pickerel Lake, where first food was adult copepods. In 1996, Pelican Lake larvae fed on copepod nauplii until 7-mm TL, followed by a switch to adult copepods and increasing numbers of cladocerans. In August juvenile perch in Pickerel Lake were eight times more abundant in 1996 then in 1995, while catches were similar between years at Pelican Lake. Juvenile perch diets in Pic...

Relationship between Larval and Juvenile Yellow Perch Abundance in Eastern South Dakota Glacial Lakes

Abstract We sought to determine if abundance of larval yellow perch Perca flavescens could predict abundance of age-0 juvenile perch in late summer. Yellow perch larvae and juveniles were sampled from six eastern South Dakota glacial lakes in 1997. The number of age-0 yellow perch caught per seine haul in late summer was positively related to larval abundance in late May and early June (N = 6, r = 0.90, P = 0.01). When data collected from two eastern South Dakota lakes in 1995 and 1996 were added to this assessment, we also found a significant positive relation (N = 10, r = 0.88, P = 0.0009). Thus, biologists in eastern South Dakota can use larval yellow perch abundance as an early indicator to determine which water bodies are likely to have a weak naturally produced year-class and then can evaluate the success of fingerling perch stocking strategies.

Total Length Reduction in Preserved Yellow Perch Larvae

Abstract The high variability in reported lengths of larval yellow perch Perca flavescens at hatching, dietary shift, and morphometric transformation may be partly caused by shrinkage that occurs after preservation. Larval yellow perch were captured, randomly assigned to one of six preservative treatments (100%, 95%, 80%, and 50% ethyl alcohol and 5% and 10% formalin), and measured (before preservation) for total length (TL). Larval yellow perch total lengths were then recorded on days 1, 7, 14, and 21 after storage in each of the six preservatives. Significant reductions in TL (11.5–14.3%) occurred during the first 24 h after fixation and larvae continued to contract at a lesser rate through day 7 in all four ethyl alcohol treatments. Total length reductions of up to 2.5% also occurred during the first 24 h in each formalin concentration. Our findings report the total length reductions of larval yellow perch at a length range used by some biologists when indexing year-class strength and during studies of...

Relations between Climatological Variables and Larval Yellow Perch Abundance in Eastern South Dakota Glacial Lakes

ABSTRACT We evaluated relationships between climatological variables and abundance of larval yellow perch (Perca flavescens) in eastern South Dakota glacial lakes. Age-0 yellow perch were collected using a 0.75 m diameter ichthyoplankton net from May through mid-June at 7 to 10 d intervals. Highest correlation coefficients with larval yellow perch abundance were for April total precipitation (r-0.95–0.99; P=0.09–0.01; three lakes), mean March wind speed (r=-0.98 to −0.99; P=0.02–0.006; two lakes), mean of May average daily temperatures (1-0.78; P=0.12; one lake) and mean May wind speed (r=-0.82; P=0.02; one lake). Given the low number of years in some samples, individual years at times had undue influence on the relationship, resulting in high correlation coefficients. Multiple regression modeling resulted in improved models for only two of the seven lakes (R2=0.90–0.98; P=0.05–0.02). However, March through May weather patterns in some combination were related to larval yellow perch abundance in all seven study lakes. Larval abundance tended to be higher in years with less wind, more precipitation, and warmer air temperatures. Whether wind, temperature, or precipitation were most influential seemed to vary by lake.

SEASONAL DYNAMICS OF AQUATIC FAUNA AND HABITAT PARAMETERS IN A PERCHED UPPER MISSOURI RIVER WETLAND

The Missouri River floodplain historically contained numerous wetlands; however, alterations to the corridor have resulted in the loss of flood-pulse processes. The annual contributions of small wetlands (<15 ha) perched on the Missouri River floodplain have not been viewed as important; however, consequences of draining or filling perched wetlands in the upper Missouri River basin remain unclear. The objective of this study was to survey aquatic fauna and basic habitat characteristics in a small perched wetland before, during, and after a connection period within a naturally functioning section of the Missouri River. Fishes, macroinvertebrates, zooplankton, and habitat parameters were sampled during May, July, and September 1997. No significant differences (P>0.05; F<4.2; df=2,9) in densities or catch-per-uniteffort among sample periods were detected for macroinvertebrates. Copepoda nauplii, calanoid Copepoda, and Bosmina spp. densities showed significant changes (P < 0.03; F > 6.1; df=2,9) and collectively surpassed 3,200 organisms/L. These densities exceeded other regional means by as much as 900%. Twentyfour fish species were documented in the wetland; however, the black bullhead, Ameiurus melas Rafinesque, dominated the fish community. Wetland depth and surface area increased during the connection period and inundated terrestrial grasses and woody debris. Decay of submerged organic matter, combined with the lack of rooted macrophytes, loss of algal productivity to flushing, and higher turbidity, may have all contributed to reduced summer dissolved oxygen levels. Avian feeding activity suggested that fishes were using the upper water column when nearly anoxic lower water column conditions existed. Although the wetland habitat may be harsh, presence of juvenile fishes and dense zooplankton populations establishes the potential importance of these water bodies to the Missouri River ecosystem.

A Standard Weight Equation to Assess the Condition of North American Lake Herring (Coregonus artedi)

Abstract We developed a 75th-percentile standard weight (Ws) equation to aid in the analysis of lake herring (Coregonus artedi) body condition over temporal periods and across populations. Weight-length data were obtained for 23,115 lake herring from 61 North American populations. The proposed equation is log10 Ws = −5.517 + 3.224 log10 TL, where Ws is the standard weight in grams and TL is the maximum total length in millimeters. The equation is valid for lake herring ≥ 100 mm and allows calculation of the relative weight (Wr) index. Significantly lower (P<0.001) Wr values were present for Lake Superior lake herring populations than for the “inland” populations, suggesting that Lake Superior herring weigh less at a given length. Based on the world record lake herring length (55.9 cm), we propose minimum standardized length categories of 13,20,28,35, and 43 cm for stock, quality, preferred, memorable, and trophy lengths, respectively. The length categories facilitate analysis across length groups and the ...

Observations of Age-0 Blue Sucker, Cycleptus elongatus Utilizing an Upper Missouri River Backwater

ABSTRACT The early life history of blue sucker (Cycleptus elongatus) is relatively unknown across its range; however, we collected seven age-0 specimens in an upper Missouri River backwater in North Dakota during the flood pulses of 1997 and 1999. Specifically, the specimens were captured in the upper 0.4 m of the water column (1.O to 2.5 m total depth) in close proximity to the backwater-channel connection points and in the margins of marsh smartweed (Polygonum coccineum) beds.

Assessment of Larval Fish Consumption by Goldeye (Hiodon alosoides) in Two Missouri River Backwaters

Abstract The presence of large numbers of adult goldeye (Hiodon alosoides) in backwater habitats of the upper Missouri River, combined with the presence of many other native fishes and their larvae, has raised questions about the predatory effect that goldeye may have on the larval fish community. Goldeye and larval fishes were sampled in backwater habitats during April, May, July, August, and September of 1997. Peak relative abundance of adult goldeye coincided with peak relative abundance of larval fishes in July. We examined the stomach contents from 161 goldeye collected in July and August to determine what proportion of the goldeye diet was composed of larval fishes. Only four stomachs contained larval fish (2.5% frequency of occurrence), and larval fishes composed less than 0.1% of the total number of food items. Corixidae, Coleoptera, and zooplankton (Copepoda and Cladocera) were the primary diet items.

Environmental Influences on Walleye Fingerling Production in Southwestern Minnesota Shallow Lakes

Abstract Shallow lakes and deep wetlands in southwestern Minnesota are being used as rearing ponds for fingerling walleye Sander vitreus; however, information about the biotic and abiotic variables that influence walleye rearing success in these water bodies is limited and inconsistent. Our objective was to identify the characteristics that most influence fall walleye fingerling production in southwestern Minnesota lacustrine wetlands. We used principal component analysis to reduce the dimensionality of the data set. A subsequent correlation analysis using the created independent variables (i.e., principal components scores) indicated that walleye fingerling production measures were positively related to total phosphorus, chlorophyll a, and total Kjeldahl nitrogen and negatively associated with Secchi disk depth and water conductivity (r = 0.70–0.74). Invertebrate densities, particularly that of zooplankton, exhibited weak but positive associations with walleye fingerling production (r = 0.48–0.57). The n...