scholarly journals Population Characteristics of Yellow Perch in a Central Appalachia Hydropower Reservoir

2018 ◽  
Vol 9 (2) ◽  
pp. 486-495
Author(s):  
Corbin D. Hilling ◽  
Nate D. Taylor ◽  
Stuart A. Welsh ◽  
Dustin M. Smith
Keyword(s):  
West Virginia ◽  
Yellow Perch ◽  
Size Structure ◽  
Management Strategies ◽  
Relative Weight ◽  
Population Characteristics ◽  
Diet Shift ◽  
Management Decisions ◽  
Ontogenetic Diet Shift ◽  
Hydropower Reservoir

Abstract Estimates of population characteristics of sport fishes inform fisheries management decisions and provide feedback on management strategies. Cheat Lake provides an unusual fishery in West Virginia because the hydropower reservoir supports a Yellow Perch Perca flavescens population. We estimated age structure, size structure, condition, total instantaneous mortality, growth, and summer diet for Cheat Lake Yellow Perch based on electrofishing collections in 2012. From 302 individuals, we observed a maximum age of 9 y. Maximum age, average size, and growth of females in the sample exceeded those of males. Cheat Lake Yellow Perch scored low on the relative weight index, but generally exhibited faster growth than other populations, even when compared by sex. Estimated annual survival was 0.63 (95% CI = 0.51–0.78), which is comparable to other exploited populations. These data support the presence of an ontogenetic diet shift from consumption of zooplankton to macroinvertebrates and fishes as Yellow Perch age. This study is the first evaluation we are aware of on Yellow Perch population characteristics in West Virginia, providing baseline data to enhance management decisions and direct future studies.

Conservation, Ecology, and Management of Catfish: The Second International Symposium

2011 ◽  
Keyword(s):  
Ictalurus Punctatus ◽  
Channel Catfish ◽  
Size Structure ◽  
Prey Availability ◽  
Relative Weight ◽  
Negative Influence ◽  
River Channel ◽  
Population Characteristics ◽  
Current Status ◽  
Platte River

<em>Abstract</em>.—Catfish angling is popular throughout North America and catfish are the most sought after fish species in the Platte River, Nebraska. However, catfish management in the Platte River is minimal as little is known about current populations. Our objective was to determine the current status of channel catfish <em>Ictalurus punctatus</em> populations in the central and lower Platte River. Specifically, we evaluated population characteristics including relative abundance, size structure and condition. The current Platte River channel catfish population appears to be comparable to many Midwestern rivers. Channel catfish populations in the central Platte River had lower relative abundances (CPUE [catch per unit effort] = 1.1 ± 0.2 versus 2.3 ± 0.2 fish/net-night using 25-mm hoop nets), higher condition (<em>W<sub>r</sub></em> [relative weight] = 92 ± 1.7 versus 83 ± 0.7 using all gears) and greater size structure (PSD [proportional size distribution] = 35 ± 7 versus 24 ± 3 using all gears) compared to lower Platte River channel catfish. Possible factors influencing differences in channel catfish population characteristics are prey availability, flow modifications, habitat characteristics, and angler exploitation. Water manipulation from the Loup River Power Canal was also identified as a possible negative influence on lower Platte River channel catfish populations because hydropeaking is likely creating a stressful environment. However, channel catfish in the central Platte River may have benefited from recent high flows that likely increased productivity and food availability in the central Platte River.

Conservation, Ecology, and Management of Catfish: The Second International Symposium

2011 ◽  
Keyword(s):  
Size Structure ◽  
Management Strategies ◽  
Age Groups ◽  
Missouri River ◽  
Population Characteristics ◽  
Fish Length ◽  
Natural Mortality ◽  
Conservation Ecology ◽  
Flathead Catfish ◽  
Tag Loss

<em>Abstract</em>.—Few studies have been conducted on angler exploitation rates or angler harvest size selectivity for flathead catfish <em>Pylodictis olivaris</em>. However, exploitation of a narrow range of age groups or sizes could affect flathead catfish population characteristics and fisheries, and management strategies may be needed to enhance fisheries if selective angler exploitation is severe. Almost 3,000 flathead catfish (305–1,209 mm total length [TL]) were marked with Carlin dangler reward tags over a 3-year period in a 92-km section of the Missouri River in northwest Missouri. Corrected angler exploitation (accounting for angler nonreporting, tag loss, and natural mortality) ranged from 4.1% to 9.6%. Angler harvest rates of flathead catfish varied by fish length. Tagged fish 305–380 mm TL were harvested in lower proportion than expected. Fifty-six percent of all fish tagged were in this size-group vested in higher proportion (50% of total) than relative abundance (27%) would suggest, as were flathead catfish ≥ 508 mm TL (17% of total tagged and 23% of total harvested). Angler exploitation rates of flathead catfish from the Missouri River did not seem excessive (<10%). However, 77% of flathead catfish harvested by anglers were less than 508 mm TL, and given that logistic regression predicted that flathead catfish between 450 and 650 mm TL had the highest probability of being harvested by anglers, harvest restrictions protecting fish less than 650 mm TL would likely shift the population size structure towards larger-sized individuals, if that was a management goal.

Ontogenetic Diet Shift in Lake Erie Age-0 Yellow Perch (Perca flavescens): A Size-Related Response to Zooplankton Density

1992 ◽  
Vol 49 (9) ◽  
pp. 1932-1937 ◽  
Author(s):  
Lin Wu ◽  
David A. Culver
Keyword(s):  
Yellow Perch ◽  
Lake Erie ◽  
Life Stage ◽  
Perca Flavescens ◽  
Field Studies ◽  
Diet Shift ◽  
Fish Size ◽  
Ontogenetic Diet Shift ◽  
Zooplankton Density ◽  
Benthic Prey

Through field studies, we demonstrated that age-0 yellow perch (Perca flavescens) in western Lake Erie underwent an ontogenetic diet shift from exclusively zooplankton to mainly benthic prey during June through August. This shift coincided with a decline in zooplankton populations in the lake. Further, laboratory experiments on feeding ontogeny suggest that the diet shift was related to fish size. Yellow perch less than 30 mm total length did not consume benthic prey either during the feeding experiments or in the field studies, while fish greater than 50 mm did at low zooplankton densities. Interactions between fish size and zooplankton density, therefore, likely determine the ontogenetic diet shift in young-of-the-year yellow perch. Growth of yellow perch declined following the zooplankton decline. Reduced growth during this life stage may extend the period of vulnerability of yellow perch to its predators, thus reducing survival and, ultimately, recruitment.

scholarly journals Population Characteristics of Yellow Perch in Dead Lake, Florida

2019 ◽  
Vol 10 (2) ◽  
pp. 296-303
Author(s):  
Scott M. Bisping ◽  
Ted J. Alfermann ◽  
Patrick A. Strickland
Keyword(s):  
Yellow Perch ◽  
Age Groups ◽  
Relative Weight ◽  
Stomach Contents ◽  
High Water ◽  
Limited Range ◽  
Population Characteristics ◽  
Diet Analysis ◽  
Thermal Refugia ◽  
Total Length

Abstract In Florida, the Yellow Perch Perca flavescens is known to exist only in the Apalachicola River watershed. We conducted a 2-y study (2015–2016) to assess population characteristics of Yellow Perch in Dead Lake, Florida. We also measured summertime (June–September 2016) water temperatures to identify temperature differences between two sections (West Arm Creek and the main pool) of Dead Lake. Using electrofishing, we collected 564 Yellow Perch ranging from 72 to 343 mm total length from West Arm Creek. An age sample showed Yellow Perch ranged in age from 0 to 6 y and strong year classes were produced in 2013 and 2015. High mean total length at age suggests Yellow Perch in Dead Lake are a fast-growing population, likely a result of limited abundance and a long growing season. This study showed low mean relative weight (Wr, 2015: 70; 2016: 67), which is similar to other southeastern populations. Stomach contents and diet analysis showed no differences between age groups, which suggests that Yellow Perch are opportunistic feeders. Dead Lake showed high water temperatures (≥28°C) during the summer months, but the spring-fed Stone Mill Creek may provide thermal refugia that allow fish to avoid stressful temperatures in the main pool of Dead Lake in summer. Limited awareness among anglers, coupled with low abundance and the fish's limited range in the state, likely contributes to the lack of exploitation of Yellow Perch in Florida.

scholarly journals Links between Phenology of Large Phytoplankton and Fisheries in the Northern and Central Red Sea

2021 ◽  
Vol 13 (2) ◽  
pp. 231
Author(s):  
John A. Gittings ◽  
Dionysios. E. Raitsos ◽  
Robert J. W. Brewin ◽  
Ibrahim Hoteit
Keyword(s):  
Red Sea ◽  
Phytoplankton Bloom ◽  
Size Structure ◽  
Management Strategies ◽  
Trophic Levels ◽  
Cell Diameter ◽  
Food Web Structure ◽  
Marine Management ◽  
Fisheries Resources ◽  
Phytoplankton Size

Phytoplankton phenology and size structure are key ecological indicators that influence the survival and recruitment of higher trophic levels, marine food web structure, and biogeochemical cycling. For example, the presence of larger phytoplankton cells supports food chains that ultimately contribute to fisheries resources. Monitoring these indicators can thus provide important information to help understand the response of marine ecosystems to environmental change. In this study, we apply the phytoplankton size model of Gittings et al. (2019b) to 20-years of satellite-derived ocean colour observations in the northern and central Red Sea, and investigate interannual variability in phenology metrics for large phytoplankton (>2 µm in cell diameter). Large phytoplankton consistently bloom in the winter. However, the timing of bloom initiation and termination (in autumn and spring, respectively) varies between years. In the autumn/winter of 2002/2003, we detected a phytoplankton bloom, which initiated ~8 weeks earlier and lasted ~11 weeks longer than average. The event was linked with an eddy dipole in the central Red Sea, which increased nutrient availability and enhanced the growth of large phytoplankton. The earlier timing of food availability directly impacted the recruitment success of higher trophic levels, as represented by the maximum catch of two commercially important fisheries (Sardinella spp. and Teuthida) in the following year. The results of our analysis are essential for understanding trophic linkages between phytoplankton and fisheries and for marine management strategies in the Red Sea.

Managing Alien Plants for Biodiversity Outcomes—the Need for Triage

2010 ◽  
Vol 3 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Paul O. Downey ◽  
Moira C. Williams ◽  
Leonie K. Whiffen ◽  
Bruce A. Auld ◽  
Mark A. Hamilton ◽  
...  
Keyword(s):  
Biodiversity Conservation ◽  
Native Species ◽  
Regional Scale ◽  
Management Strategies ◽  
Alien Plants ◽  
Plant Management ◽  
Policy Reforms ◽  
Management Decisions ◽  
Alien Plant ◽  
Triage System

AbstractRecognition that alien plants pose a significant threat to biodiversity has not always translated into effective management strategies, policy reforms, and systems to establish priorities. Thus, many alien plant management decisions for the protection of biodiversity occur with limited knowledge of what needs to be protected (other than biodiversity in a generalized sense) or the urgency of actions. To rectify this, we have developed a triage system that enables alien plant management decisions to be made based on (1) the urgency of control relative to the degree of threat posed to biodiversity, compared with (2) the likelihood of achieving a successful conservation outcome as a result of alien plant control. This triage system is underpinned by a two-step approach, which identifies the biodiversity at risk and assesses sites to determine priorities for control. This triage system was initially developed to manage the threat posed by bitou bush to native species in New South Wales (NSW), Australia. It has subsequently been improved with the national assessment of lantana in Australia, and the adaptation from a single to multiple alien plant species approach on a regional scale. This triage system identifies nine levels of priority for alien plant management aimed at biodiversity conservation, ranging from immediate, targeted action to limited or no action. The development of this approach has enabled long-term management priorities to be set for widespread alien plants that are unlikely to be eradicated. It also enables control to occur in a coordinated manner for biodiversity conservation at a landscape scale, rather than as a series of individual unconnected short-term actions.

Balancing Fisheries Management and Water Uses for Impounded River Systems

2008 ◽  
Keyword(s):  
Size Structure ◽  
Management Strategies ◽  
Historical Context ◽  
Lepomis Macrochirus ◽  
Large Body ◽  
Early Maturation ◽  
Reservoir Species ◽  
Clear Identification ◽  
Management Approaches ◽  
Underlying Mechanisms

<em>Abstract</em>.—Although stunting is a fairly common phenomenon in fishes, confusion remains about underlying mechanisms and appropriate management strategies. Herein, I summarize current literature to provide a synthetic look at factors that can cause stunting and consider associated management strategies. First, I provide historical context by reviewing early literature, much of which is focused on density-dependent slow growth as the cause of stunting. A brief summary of more recent literature, however, suggests that stunting is often more complex than early investigations might indicate, and mechanisms such as early maturation and overexploitation of adults are considered. Because the bluegill <em>Lepomis macrochirus </em>is an extremely common reservoir species, a large body of literature related to its population size structure and associated management strategies is available. Therefore, I use bluegill as a model system to describe how various mechanisms might lead to stunting and indicate important considerations from a management standpoint. In the final section, I review management strategies and argue, among other things, that consistent language, clear identification of underlying mechanisms, and multifaceted management approaches are necessary for robust results when dealing with stunted populations.

A Bayesian spatiotemporal approach to inform management unit appropriateness

2019 ◽  
Vol 76 (2) ◽  
pp. 217-237 ◽  
Author(s):  
Rujia Bi ◽  
Yan Jiao ◽  
Can Zhou ◽  
Eric Hallerman
Keyword(s):  
Great Lakes ◽  
Fisheries Management ◽  
Yellow Perch ◽  
Management Strategies ◽  
Computational Cost ◽  
Bayesian Hierarchical ◽  
Fish Stocks ◽  
Spatiotemporal Correlation ◽  
Management Actions ◽  
Gill Net

One prerequisite for sustainable fisheries management is to match management actions with biological processes. Stocks are fundamental units for fisheries management. Understanding the spatial structure of fish stocks is critical for conducting defensible stock assessments, applying efficient management strategies, and ensuring the sustainability of fish stocks. Yellow perch (Perca flavescens) is an important fishery in the Great Lakes. The appropriateness of its management units (MUs) has been identified as of high concern by the Great Lakes Fisheries Commission. Here we established integrated nested Laplace approximations and stochastic partial differential equations as two powerful tools for modeling spatiotemporal patterns of fish relative biomass. These fast computational approaches were applied to fit a Bayesian hierarchical hurdle model to occurrence and positive mass of yellow perch caught in gill-net surveys. Yellow perch relative biomass index has clear temporal variation and spatial heterogeneity, with the two middle MUs for yellow perch within Lake Erie merging together. The method explicitly models the spatiotemporal correlation structure inherent in biomass survey data at a reasonable computational cost, and the estimated spatiotemporal correlation informs stock structure.

scholarly journals Characterising populations living close to intensive farming and composting facilities in England

2020 ◽  
Vol 15 (3) ◽  
Author(s):  
Philippa Douglas ◽  
Daniela Fecht ◽  
Deborah Jarvis
Keyword(s):  
Air Pollution ◽  
Urban Areas ◽  
Management Strategies ◽  
Population Characteristics ◽  
Anthropogenic Sources ◽  
Intensive Farming ◽  
Urban Classification ◽  
Risk Management Strategies ◽  
Composting Facilities ◽  
Composting Facility

Abstract Bioaerosol exposure has been linked to adverse respiratory conditions. Intensive farming and composting facilities are important anthropogenic sources of bioaerosols. We aimed to characterise populations living close to intensive farming and composting facilities. We also infer whether the public are becoming more concerned about anthropogenic bioaerosol emissions, using reports of air pollution related incidents attributed to facilities. We mapped the location of 1,257 intensive farming and 310 composting facilities in England in relation to the resident population and its characteristics (sex and age), area characteristics (deprivation proxy and rural/urban classification) and school locations stratified by pre-defined distance bands from these bioaerosol sources. We also calculated the average number of air pollution related incidents per year per facility. We found that more than 16% of the population and 15% of schools are located within 4,828 m of an intensive farming facility or 4,000 m of a composting facility; few people (0.01 %) live very close to these sites and tend to be older people. Close to composting facilities, populations are more likely to be urban and more deprived. The number of incidents were attributed to a small proportion of facilities; population characteristics around these facilities were similar. Results indicate that populations living near composting facilities (particularly>250 to ⩽ 4,000 m) are mostly located in urban areas (80%–88% of the population), which supports the need for more community health studies to be conducted. Results could also be used to inform risk management strategies at facilities with higher numbers of incidents.

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