scholarly journals QUANTIFYING HABITAT CONCEPTS: POPULATION IMPACTS OF STAGE-SPECIFIC SALINITY RELATIONSHIPS FOR BLACK DRUM (POGONIAS CROMIS) IN THE UPPER LAGUNA MADRE, TEXAS USA

2020 ◽  
Vol 72 (1) ◽  
Author(s):  
Zachary Olsen
Keyword(s):  
Life Stage ◽  
Aquatic Organisms ◽  
Management Tool ◽  
Proof Of Concept ◽  
Laguna Madre ◽  
Widespread Application ◽  
Early Maturation ◽  
Demographic Models ◽  
Young Of The Year ◽  
Population Effects

Abstract Environmental factors can often have population effects on aquatic organisms, though studies of environmental effects are often specific to a given life stage. Stage-structured demographic models provide a means of exploring the multivariate suite of life history parameters associated with a population and can provide a tool for understanding population-wide impacts of single stage events (e.g., mortality and fecundity). Here, the unique dynamics observed for an isolated population of black drum (Pogonias cromis) and the population-wide impacts of salinity as a driver of young-of-the-year (YOY) survival were investigated. This modeling exercise revealed that the dynamics observed in the black drum population are potentially driven by increased survival in the post-settler/YOY stage and that this increased survival is at least partially a result of the higher salinities that typify the Upper Laguna Madre of Texas, a hypersaline estuary (34% increase in population growth rate across the range of salinity examined). Early maturation in this population was also shown to have the potential to provide infrequent, large pulses of fecundity to the population. Quantifying the population-wide impact of such drivers can place management decisions into the context of the environment and provide both a proof-of-concept for specific management action and realistic expectations for managers and constituents alike. Without such formal quantification, it will be difficult for habitat concepts to move from an abstract management tool to widespread application.

scholarly journals Effect of Collection Month, Visible Light, and Air Movement on the Attraction of Male Agriotes obscurus L. (Coleoptera: Elateridae) Click Beetles to Female Sex Pheromone

Insects ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 729
Author(s):  
Joyce P. S. Leung ◽  
Jenny S. Cory ◽  
J. Todd Kabaluk ◽  
Alida F. Janmaat
Keyword(s):  
Sex Pheromone ◽  
Visible Light ◽  
Life Stage ◽  
Management Tool ◽  
Female Sex Pheromone ◽  
Click Beetles ◽  
Agriotes Obscurus ◽  
Female Sex ◽  
Air Movement ◽  
Click Beetle

Elaterid female sex pheromone, while currently used for monitoring the adult life stage (click beetle), has only recently been explored as a potential management tool. Consequently, there is little understanding of how abiotic and biotic conditions influence the response of click beetles to the pheromone. We examined whether the response of male Agriotes obscurus L. (Coleoptera: Elateridae) beetles to a cellulose-based formulation of female sex pheromone (‘pheromone granules’) is influenced by air movement, presence of visible light, and month of beetle collection. In addition, we investigated the distance from which beetles were attracted to the pheromone granules. Click beetle response was determined by measuring movement parameters in free-walking arena experiments. The response to pheromone was not affected by the presence or absence of visible light. We found that beetles collected earlier in the season had increased activity and interaction with pheromone under moving air conditions, compared to beetles collected later. When controlling for storage time, we confirmed that individuals collected in May were less active than beetles collected in March and April. In the field, beetles were recaptured from up to 14 m away from a pheromone granule source, with over 50% being recovered within 4.4 h from a distance of 7 m or less. Understanding how abiotic and biotic factors affect pest response to pheromone can lead to more effective and novel uses of pheromone-based management strategies.

scholarly journals Population-level effects of immunocontraception in white-tailed deer (Odocoileus virginianus)

2008 ◽  
Vol 35 (6) ◽  
pp. 494 ◽  
Author(s):  
Allen T. Rutberg ◽  
Ricky E. Naugle
Keyword(s):  
New York ◽  
Odocoileus Virginianus ◽  
Population Change ◽  
Population Level ◽  
Management Tool ◽  
Strongly Correlated ◽  
Management Tools ◽  
Annual Population ◽  
Population Effects

In North America, dense populations of white-tailed deer (Odocoileus virginianus) in suburbs, cities and towns have stimulated a search for new population-management tools. Most research on deer contraception has focused on the safety and efficacy of immunocontraceptive vaccines, but few studies have examined population-level effects. We report here results from two long-term studies of population effects of the porcine zona pellucida (PZP) immunocontraceptive vaccine, at the National Institute of Standards and Technology (NIST), Gaithersburg, Maryland, USA, and at Fire Island National Seashore (FIIS), New York, USA. Annual population change at NIST was strongly correlated with population fertility (rP = 0.82, P = 0.001); when population fertility at NIST dropped below 0.40 fawns per female, the population declined. Contraceptive treatments at NIST were associated with a 27% decline in population between 1997 and 2002, and fluctuated thereafter with the effectiveness of contraceptive treatments. In the most intensively treated segment of FIIS, deer population density declined by ~58% between 1997 and 2006. These studies demonstrate that, in principle, contraception can significantly reduce population size. Its usefulness as a management tool will depend on vaccine effectiveness, accessibility of deer for treatment, and site-specific birth, death, immigration, and emigration rates.

The influence of floating spheres on evaporation suppression under different climatic conditions

2021 ◽  
Author(s):  
Maram M. Shalaby ◽  
Ibrahim N. Nassar ◽  
Ahmed M. Abdallah
Keyword(s):  
Water Surface ◽  
Rainfall Variability ◽  
Aquatic Organisms ◽  
Climatic Conditions ◽  
Management Tool ◽  
Control Treatment ◽  
Suppression Efficiency ◽  
Evaporation Suppression ◽  
Water Ecology ◽  
Microalgae Growth

<p>Global warming and population growth increase the need for better management of freshwater resources, in particular in arid and semi-arid regions. Due to increased rainfall variability,  reservoirs became a vital management tool that stores the water during rainfall, thus decrease flood risks and supply water during drought periods. However, large amounts of water are lost by evaporation, which markedly affects reservoirs’ function of ensuring water availability. In Egypt, about 20.0% of the country's Nile share (12.1 to 15.4 billion m<sup>3</sup>) are lost annually by evaporation from Lake Nasser. The floating covers, i.e. spheres, shade the water surface and act as a physical barrier that decreases energy flux into the water, thus decrease evaporation. Studies that compare the evaporation suppression efficiency of the floating covers, over different climatic conditions, while considering its impact on the water ecology are limited.</p><p>A field experiment in an outdoor setting (class A-pan) was conducted for nine months (March to November) in two locations that vary in their climatic conditions, i.e. Aswan and Damanhur, representing northern and southern Egypt, respectively. The water surface was covered by white, black, or multicolor spheres, in addition to the control. Daily evaporation rate (ER), water temperature (WT), evaporation suppression efficiency (ESE), were determined. Moreover, the microalgae growth was measured as an indicator of water ecology.  </p><p>Obtained results revealed massive evaporation losses from the uncovered water surface (control) in Aswan location, in which the nine-month average was 2.25 times higher than in Damanhour location. The floating spheres reduced ER in both locations, in particular the white spheres. The ESE in Aswan was less than in Damanhour location. The ESE in Damanhour was 63.38, 58.13, and 54.8%, while in Aswan was 48., 42.5, and 41.6% for white, multicolor and black spheres, respectively. Floating spheres decreased WT in the morning and mid-day, while in the evening the control treatment was the coldest, indicating partial isolation of covered water surface. Irrespective of the spheres’ color, the spheres had no detrimental effect on microalgae growth, indicating enough light penetration and gas exchange through the gaps between spheres.</p><p>In conclusion, the floating spheres is an effective mean for evaporation suppression and its efficiency is dependent on the climate and spheres’ color. The ESE of spheres is lower in environments with lower relative humidity. The white spheres are recommended for evaporation suppression without negative impacts on microalgae growth which could be a viable indicator for the ecology of the water ecosystem. Further studies on larger water reservoirs are needed while considering several aquatic organisms.</p>

scholarly journals Up and away: ontogenic transference as a pathway for aerial dispersal of microplastics

2018 ◽  
Vol 14 (9) ◽  
pp. 20180479 ◽  
Author(s):  
Rana Al-Jaibachi ◽  
Ross N. Cuthbert ◽  
Amanda Callaghan
Keyword(s):  
Life Stage ◽  
Malpighian Tubule ◽  
Aquatic Organisms ◽  
Terrestrial Ecosystems ◽  
Life Stages ◽  
Aerial Dispersal ◽  
Terrestrial Life ◽  
Reduced Rate ◽  
First Time ◽  
Feeding Larva

Microplastics (MPs) are ubiquitous pollutants found in marine, freshwater and terrestrial ecosystems. With so many MPs in aquatic systems, it is inevitable that they will be ingested by aquatic organisms and be transferred up through the food chain. However, to date, no study has considered whether MPs can be transmitted by means of ontogenic transference, i.e. between life stages that use different habitats. Here, we determine whether fluorescent polystyrene beads could transfer between Culex mosquito life stages and, particularly, could move into the flying adult stage. We show for the first time that MPs can be transferred ontogenically from a feeding (larva) into a non-feeding (pupa) life stage and subsequently into the adult terrestrial life stage. However, transference is dependent on particle size, with smaller 2 µm MPs transferring readily into pupae and adult stages, while 15 µm MPs transferred at a significantly reduced rate. MPs appear to accumulate in the Malpighian tubule renal excretion system. The transfer of MPs to the adults represents a potential aerial pathway to contamination of new environments. Thus, any organism that feeds on terrestrial life phases of freshwater insects could be impacted by MPs found in aquatic ecosystems.

scholarly journals Life Stage-Specific Hydropeaking Flow Rules

2019 ◽  
Vol 11 (6) ◽  
pp. 1547 ◽  
Author(s):  
Daniel Hayes ◽  
Miguel Moreira ◽  
Isabel Boavida ◽  
Melanie Haslauer ◽  
Günther Unfer ◽  
...  
Keyword(s):  
Life History ◽  
Energy Production ◽  
Life Stage ◽  
Aquatic Organisms ◽  
Time Of Day ◽  
Temperature Changes ◽  
Life History Stages ◽  
Flow Fluctuations ◽  
Life Cycle Stages ◽  
Hydropower Plants

Peak-operating hydropower plants are usually the energy grid’s backbone by providing flexible energy production. At the same time, hydropeaking operations are considered one of the most adverse impacts on rivers, whereby aquatic organisms and their life-history stages can be affected in many ways. Therefore, we propose specific seasonal regulations to protect ecologically sensitive life cycle stages. By reviewing hydropeaking literature, we establish a framework for hydrological mitigation based on life-history stages of salmonid fish and their relationship with key parameters of the hydrograph. During migration and spawning, flows should be kept relatively stable, and a flow cap should be implemented to prevent the dewatering of spawning grounds during intragravel life stages. While eggs may be comparably tolerant to dewatering, post-hatch stages are very vulnerable, which calls for minimizing or eliminating the duration of drawdown situations and providing adequate minimum flows. Especially emerging fry are extremely sensitive to flow fluctuations. As fish then grow in size, they become less vulnerable. Therefore, an ‘emergence window’, where stringent thresholds on ramping rates are enforced, is proposed. Furthermore, time of day, morphology, and temperature changes must be considered as they may interact with hydropeaking. We conclude that the presented mitigation framework can aid the environmental enhancement of hydropeaking rivers while maintaining flexible energy production.

scholarly journals Exposure effects of the UV-filter 4-MBC to "Solea senegalensis" metamorphosis

2021 ◽  
Author(s):  
Mário Araújo ◽  
Amadeu Soares ◽  
Marta Monteiro
Keyword(s):  
Critical Period ◽  
Life Stage ◽  
Aquatic Organisms ◽  
Daily Basis ◽  
Solea Senegalensis ◽  
Control Group ◽  
Glutathione S Transferase ◽  
Short Term ◽  
Short Term Exposure

Abstract Many personal care products integrate UV-filters, such as 4-methylbenzylidene camphor (4-MBC) which has been detected in aquatic habitats. Possible effects of 4-MBC to aquatic organisms have been poorly studied. Therefore, the main objective of this work is to study the effects of 4-MBC exposure to Solea senegalensis during metamorphosis, a sensitive life stage of this flatfish. To achieve this, at the beginning of metamorphosis (13 days after hatching, dah) fish were exposed to 4-MBC (0.2–2.0 mg L− 1) for 48 h. After this period, fish were transferred to clean medium and were fed and maintained until more than 80% of fish in control group completed the metamorphosis (24 dah). Mortality, malformations and metamorphosis progression were studied on a daily basis. In addition, growth, behavior and biochemical markers of neurotransmission (acetylcholinesterase, AChE), oxidative stress (catalase, CAT; glutathione S-transferase, GST, and lipid peroxidation, LPO) and anaerobic metabolism (lactate dehydrogenase, LDH) were determined at the end of the experiment. An acceleration of metamorphosis progression was observed during and 2 days after the 4-MBC exposure in all concentrations tested. In addition, decreased length, inhibition of CAT activity and induction of oxidative damage (LOEC = 0.928 mg L− 1 4-MBC for length, CAT and LPO) were observed. A short-term exposure to 4-MBC at the onset of metamorphosis, a critical period of development, affected S. senegalensis at several levels of organization, even after nine days in clean medium, including growth and metamorphosis progression, suggesting possible long-term adverse effects to this species.

scholarly journals Physiological, Developmental, and Biomarker Responses of Zebrafish Embryos to Sub-Lethal Exposure of Bendiocarb

Water ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 204
Author(s):  
Gyöngyi Gazsi ◽  
Zsolt Czimmerer ◽  
Bence Ivánovics ◽  
Izabella Roberta Berta ◽  
Béla Urbányi ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Heart Rate ◽  
Adverse Effects ◽  
Life Stage ◽  
Larval Growth ◽  
Aquatic Organisms ◽  
Early Life Stage ◽  
World Health ◽  
Reduced Body ◽  
Health Organization

Bendiocarb is a broad-spectrum insecticide recommended for malaria control by the World Health Organization (WHO). Still, bendiocarb poses a toxic risk to populations of nontargeted aquatic organisms. Thus, our study was aimed to evaluate the sub-lethal effects of bendiocarb exposure on zebrafish (Danio rerio) embryos by assessing of physiological, developmental, and biochemical parameters. Bendiocarb-induced adverse effects on embryonic development, larval growth, heart rate, changes in phase II detoxifying enzyme glutathione-S-transferase (GST) activity, oxidative stress-related enzyme activities (superoxide dismutase (SOD), catalase (CAT)), and the damage-linked biomarker lipid peroxidation (LPO) in early life stage zebrafish were investigated. Our results highlight that the selected nonlethal concentrations (96 h median lethal concentration in this study was 32.52 mg/L−1) of bendiocarb inflicted adverse effects resulting in embryo deformities (96 h EC50 = 2.30 mg L−1), reduced body- and notochord length (above 0.75 and 0.39 mg L−1 bendiocarb concentrations at 96 hpf, respectively), oxidative stress, and altered heart rate (above 0.4 mg L−1 at 48 hpf) in the studied model system.

scholarly journals Mitigation of lampricide toxicity to juvenile lake sturgeon: the importance of water alkalinity and life stage

2019 ◽  
Vol 7 (1) ◽  
Author(s):  
Scott L J Hepditch ◽  
Laura R Tessier ◽  
Jonathan M Wilson ◽  
Oana Birceanu ◽  
Lisa M O’Connor ◽  
...  
Keyword(s):  
Great Lakes ◽  
Life Stage ◽  
Late Summer ◽  
Sea Lamprey ◽  
Lake Sturgeon ◽  
High Alkalinity ◽  
Young Of The Year

Lay Summary Young-of-the-year lake sturgeon living in waters of high alkalinity are susceptible to mortality when exposed to 3-trifluoromethyl-4-nitrophenol (TFM), a pesticide used to control invasive sea lamprey in the Great Lakes. This risk may be reduced, however, by delaying TFM treatments to late-summer/fall, when sturgeon are larger and accumulate TFM more slowly.

scholarly journals Rh glycoprotein immunoreactivity in the skin and its role in extrabranchial ammonia excretion by the sea lamprey (Petromyzon marinus) in fresh water

2017 ◽  
Vol 95 (2) ◽  
pp. 95-105 ◽  
Author(s):  
S.D. Blair ◽  
M.P. Wilkie ◽  
S.L. Edwards
Keyword(s):  
Larval Stage ◽  
Life Stage ◽  
Petromyzon Marinus ◽  
Ammonia Excretion ◽  
Aquatic Organisms ◽  
Sea Lamprey ◽  
Life Stages ◽  
Relative Importance ◽  
Sea Lampreys ◽  
Protein Rich

Aquatic organisms employ various strategies to excrete ammonia across the gills, skin, and (or) renal routes. During three different stages of their life cycle, we hypothesized that the basal vertebrate sea lamprey (Petromyzon marinus L., 1758) used the skin as a route for ammonia excretion. Measurements of ammonia excretion using divided flux chambers revealed that extrabranchial sites (skin plus renal) of ammonia excretion were quantitatively more important in larval sea lampreys, but following metamorphosis, the gills became the dominant route of excretion in juvenile sea lampreys. Despite the greater relative importance of the skin in the larval stage, Rh glycoprotein isoforms Rhbg, Rhcg1, and Rhcg2 were detected in the skin in all three sea lamprey life stages examined, but the patterns of expression were dependent on the life stage. We conclude that, during the relatively sedentary filter-feeding larval stage, extrabranchial routes play an equally important role as the gill in facilitating ammonia excretion. However, the gills by virtue of their extensive branchial vasculature become the dominant route of ammonia excretion following metamorphosis because of the need to offload greater amounts of ammonia arising from higher rates of basal ammonia production and the potential to excrete higher amounts of ammonia following ingestion of protein-rich blood in the parasitic stage.

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