Unwanted Species Research Articles

Evaluación de la Sostenibilidad de la Pesquería de Langosta Verde (Panulirus gracilis) en Cabo San Francisco: Un Enfoque Multidimensional

The present study was carried out with the purpose of gathering updated information on the fishing resources existing in the San Francisco del Cabo parish; with the objective of diagnosing the current situation of the green lobster (Panulirus gracilis) fishery in the San Francisco del Cabo fishing cove. The methodology used was a descriptive quantitative and deductive-synthetic approach, using surveys with simple random sampling to 30 fishermen of the community, which addressed biological, economic and social aspects, as well as the fishermen's perception of the sustainability of the fishery. Data collection was conducted between July and December 2024, coinciding with the green lobster catching season. It is determined that a high percentage of fishermen catch lobsters below the minimum size of 26 cm, which compromises the viability of the populations. In addition, the use of non-selective fishing gear contributes to bycatch of unwanted species and marine habitat degradation. The research revealed that 80% of the fishermen consider that training in responsible fishing practices is necessary, and 87% requested support from the government and organizations to address current challenges. The implementation of a participatory management plan involving all relevant stakeholders was proposed, highlighting the importance of establishing a collaborative framework between fishermen, authorities and scientists to ensure the long-term sustainability of the fishery and the well-being of local communities.

Platinum single atoms on titania aid dye photodegradation whereas platinum nanoparticles do not.

The photocatalytic degradation of unwanted organic species has been investigated for decades using modified and non-modified titania nanostructures. In the present study, we investigate the co-catalytic effect of single atoms (SAs) of Pt and Pt nanoparticles on titania substrates on the degradation of the two typical photodegradation model pollutants: Acid Orange 7 (AO7) and Rhodamine B (RhB). For this, we use highly defined sputter deposited anatase layers and load them with Pt SAs at different loading densities or alternatively with Pt nanoparticles. We find that the Pt SAs have strong accelerating effects (already for a low loading density of ∼105 SAs μm-2) on the photodegradation of AO7, whereas Pt nanoparticles do hardly have an effect on the decay kinetics. The main beneficial effect of SA Pt is facilitated superoxide formation, which for SAs is significantly enhanced. Overall, the work demonstrates that Pt SA co-catalysts can have a beneficial effect not only for the well-studied use of H2 generation, but also in the photocatalytic degradation of pollutants-this is particularly the case if the degradation is dominated by a conduction band electron transfer to dissolved O2 in the solution.

PV Silicon Recovery for Lithium Ion Battery Anodes

As solar photovoltaic (PV) devices across the globe reach the end of their approximately 30-year lifetimes, an emerging challenge is how to handle the waste from large volumes of end-of-life (EOL) PV modules. It is projected that the cumulative mass of EOL PV modules could be up to 8 million tonnes (Mt) by 2030 so recovery of high value materials from these EOL modules through a cost efficient recycling process would minimize environmental impacts compared to disposing them in landfills[1]. A typical recycling process for EOL PV modules involves mechanical disassembly, separation of the tempered cover glass and silicon wafer followed by purification and recovery of other constituents such as Pb or Ag with the goal of reinstating the recovered materials as a PV module. However, since new module prices continue to decline and the recovered PV modules typically have a shorter lifetime and lower efficiency, the economic value of using the recovered PV materials to manufacture a new PV module is uncertain[2]. Since silicon, particularly boron-doped, is a promising candidate for next-generation anodes for lithium-ion batteries (LIB), recovering the silicon from PV modules for use in LIB anodes could be an attractive alternative. A ball milling process was developed at Oak Ridge National Laboratory to prepare ball milled silicon from washed silicon boules as well as EOL PV modules sourced from a commercial PV module recycler. In this talk we will be discussing the purification process, contaminant removal requirements and key anode performance metrics of recycled PV silicon materials. Organic acid washing with and without microwave-treatment as the heat source was conducted on ball milled boron-doped silicon and reference undoped silicon. The organic acid washing was conducted several times and followed by centrifugation and drying to attempt to remove unwanted contaminant species and compared to a single step microwave-assisted process. The initial carbon species present after ball milling the silicon remained on the ball milled silicon based on FTIR data and the structure of the ball milled silicon was unchanged based on XRD analysis. Elemental analysis and half cells tests were conducted to observe the effect of boron-doping and contaminants inherent to the EoL PV Si material with pristine boron-doped silicon showing noticeably better performance than non-doped ball milled silicon or contaminated silicon PV silicon. Determining the maximum amount of each potential contaminant from PV panels will help facilitate these materials being introduced into local supply chains as a silicon precursor material for more highly engineered silicon anode materials. IRENA, I.-P., End-of-Life Management: Solar Photovoltaic Panels 2016: International Renewable Energy Agency and International Energy Agency Photovoltaic Power Systems.A. Wade, P.S., K. Drozdiak, E. Brutsch. Beyond Waste – The Fate of End-of-Life Photovoltaic Panels from Large Scale PV Installations in the EU. The Socio-Economic Benefits of High Value Recycling Compared to Re-Use. in 33rd European Photovoltaic Solar Energy Conference and Exhibition. 2017.

The Prevalence of Killer Yeasts in the Gardens of Fungus-Growing Ants and the Discovery of Novel Killer Toxin named Ksino.

Killer toxins are proteinaceous antifungal molecules produced by yeasts, with activity against a wide range of human and plant pathogenic fungi. Fungus gardens of attine ants in Brazil were surveyed to determine the presence of killer toxin-producing yeasts and to define their antifungal activities and ecological importance. Our results indicate that up to 46% of yeasts isolated from specific fungal gardens can be killer yeasts, with an overall prevalence of 17% across all strains tested. Killer yeasts were less likely to inhibit the growth of yeasts isolated from the same environment but more effective at inhibiting yeast isolated from other environments, supporting a role for killer yeasts in shaping community composition. All killer yeasts harbored genome-encoded killer toxins due to the lack of cytoplasmic toxin-encoding elements (i.e., double-stranded RNA satellites and linear double-stranded DNAs). Of all the killer yeasts identified, an isolate of Candida sinolaborantium showed a broad spectrum of antifungal activities against 57% of yeast strains tested for toxin susceptibility. The complete genome sequence of C. sinolaborantium identified a new killer toxin, Ksino, with primary and tertiary structure homology to the Saccharomyces cerevisiae killer toxin named Klus. Genome-encoded homologs of Ksino were found in yeast strains of Saccharomycetes and Pichiomycetes, as well as other species of Ascomycota and Basidiomycota filamentous fungi. This demonstrates that killer yeasts can be widespread in attine ant fungus gardens, possibly influencing fungal community composition and the importance of these complex microbial communities for discovering novel antifungal molecules.

Predicting and Prioritising Community Assembly: Learning Outcomes via Experiments.

Community assembly provides the foundation for applications in biodiversity conservation, climate change, invasion, restoration and synthetic ecology. However, predicting and prioritising assembly outcomes remains difficult. We address this challenge via a mechanism-free approach useful when little data or knowledge exist (LOVE; Learning Outcomes Via Experiments). We carry out assembly experiments ('actions', here, random combinations of species additions) potentially in multiple environments, wait, and measure abundance outcomes. We then train a model to predict outcomes of novel actions or prioritise actions that would yield the most desirable outcomes. Across 10 single- and multi-environment datasets, when trained on 89 randomly selected actions, LOVE predicts outcomes with 0.5%-3.4% mean error, and prioritises actions for maximising richness, maximising abundance, or removing unwanted species, with 94%-99% mean true positive rate and 10%-84% mean true negative rate across tasks. LOVE complements existing mechanism-first approaches for community ecology and may help address numerous applied challenges.

Can pots be an alternative fishing gear to gillnets? A Mediterranean case study

Small-scale coastal fisheries in the Mediterranean often employ gillnets, a widely used gear worldwide. The disadvantages of gillnets in this fishery include high bycatch levels of unwanted species and consequent discards. Moreover, spatial conflict with other gears and dolphin depredation often results in considerable economic loss. Alternative fishing methods are being tested. This study investigated whether, in small-scale fisheries in the Adriatic Sea, pots can ensure sustainable harvest of mantis shrimp (Squilla mantis), a major target demersal species in terms of landings, and possibly replace traditional gillnets. We adopted a multidisciplinary approach to investigate the catch efficiency, biological impact, and socio-economic effects of the two fishing methods. We found different species compositions in gillnet and pot catches. Gillnets yielded a greater number of discarded species of no commercial value, whereas pots caught a greater amount of mantis shrimp. Finally, a profit analysis indicated that pot fishery has the potential to increase profits for the commercial fishing industry. This study suggests that pots provide a more sustainable fishing method, both in terms of revenue and environmental impact.

Effect on catch efficiency and bycatch by introducing an Excluder device in the trawl fishery for lesser sandeel (Ammodytes marinus).

Sampling of the North Sea trawl fishery for lesser sandeel (Ammodytes marinus) showed that 96% of the catch weight consisted of the target species, and experimental sea trials demonstrated that the observed small bycatch percentages of haddock (Melanogrammus aeglefinus), mackerel (Scomber scombrus) and grey gurnard (Eutrigla gurnardus) could be significantly lowered by inserting a netting-based sorting device, an Excluder, in front of the codend. The sandeel fishery is conducted with small meshes in the codend, due to the small size and elongated body shape of this species. It is not mandatory for sandeel trawls to have any other selection devices than the small-meshed codend, and this can potentially cause problems with bycatch of unwanted species, if these are abundant on the fishing grounds. Therefore, we sampled the catch composition in this fishery and further, we compared the capture efficiency and species composition of a standard trawl, and one fitted with an additional sorting device called the Excluder. Overall, results showed small percentages of bycatch in the trips sampled and during the trials, the excluder significantly reduced the bycatches of mackerel, grey gurnard, and haddock above certain sizes. For other bycatch species results were inconclusive due to wide confidence limits affected by low bycatch numbers during the trials. The overall capture efficiency for the target species was not affected by adding the excluder in the trawl except for a significant reduction for a few semi-centimetre groups of the largest sizes of the species. These results highlight the potential of the Excluder as a bycatch reduction tool in the sandeel fishery for situations where bycatch can constitute a problem.

Multidecadal vegetation transformations of a New Mexico ponderosa pine landscape after severe fires and aerial seeding.

Wildfires and climate change increasingly are transforming vegetation composition and structure, and postfire management may have long-lasting effects on ecosystem reorganization. Postfire aerial seeding treatments are commonly used to reduce runoff and soil erosion, but little is known about how seeding treatments affect native vegetation recovery over long periods of time, particularly in type-converted forests that have been dramatically transformed by the effects of repeated, high-severity fire. In this study, we analyze and report on a rare long-term (23-year) dataset that documents vegetation dynamics following a 1996 post-fire aerial seeding treatment and a subsequent 2011 high-severity reburn in a dry conifer landscape of northern New Mexico, USA. Repeated surveys between 1997 and 2019 of 49 permanent transects were analyzed for differences in vegetation cover, richness, and diversity between seeded and unseeded areas, and to characterize the development of seeded and unseeded vegetation communities through time and across gradients of burn severity, elevation, and soil-available water capacity. Seeded plots showed no significant difference in bare ground cover during the initial years postfire relative to unseeded plots. Postfire seeding led to a clear and sustained divergence in herbaceous community composition. Seeded plots had a much higher cover of non-native graminoids, primarily Bromus inermis, a likely contaminant in the seed mix. High-severity reburning of all plots in 2011 reduced native graminoid cover by half at seeded plots compared with both prefire levels and with plots that were unseeded following the initial 1996 fire. In addition, higher fire severity was associated with increased non-native graminoid cover and reduced native graminoid cover. This study documents fire-driven ecosystem transformation from conifer forest into a shrub-and-grass-dominated system, reinforced by aerial seeding of grasses and high-severity reburning. This unique long-term dataset illustrates that post-fire seeding carries significant risks of unwanted non-native species invasions that persist through subsequent fires-thus alternative postfire management actions merit consideration to better support native ecosystem resilience given emergent climate change and increasing disturbance. This study also highlights the importance of long-term monitoring of postfire vegetation dynamics, as short-term assessments miss key elements of complex ecosystem responses to fire and postfire management actions.

Биологическая эффективность способа инъекции гербицидов и их смесей в стволы деревьев нежелательных пород

Целью работы являлось совершенствование регулирования состава и густоты древостоев способом инъекции гербицидов и их смесей в стволы деревьев лиственных пород для повышения лесоводственной эффективности, снижения химической и токсической нагрузки на лесные экосистемы. Объектами исследований являлись отдельные деревья ольхи серой и осины вегетативного происхождения в фазе жердняка в смешанных насаждениях. В результате анализа отечественной и зарубежной литературы по проблеме были отобраны перспективные для изучения гербициды – торнадо (водный раствор, 360 г/л глифосата в виде изопропиламинной соли) и арбонал (водорастворимый концентрат, 250 г/л имазапира) и заложены полевые опыты с отобранными гербицидами. В четырех полевых опытах определялась биологическая эффективность действия гербицидов и их смесей на деревья ольхи серой и осины в смешанных насаждениях. В результате установлена высокая эффективность действия гербицида арбонал в дозах 0,08 и 0,16 мл/дерево, а также смесей торнадо (0,12–0,25 мл/дерево) + арбонал (0,06–0,08 мл/дерево) на ольху серую. По действию на осину наиболее эффективным было применение торнадо 0,20 и 0,55 мл/дерево, арбонала (0,16 мл/дерево) и смесей торнадо (0,20 мл/дерево) + арбонал (0,08 мл/дерево) и торнадо (0,25 мл/дерево) + арбонал (0,06 мл/дерево). Ольха серая проявила большую устойчивость к примененным гербицидам в год обработки, однако следует ожидать усиления действия гербицидов в следующем вегетационном сезоне. Установлено, что применение гербицидов торнадо и арбонал, а также их смесей в различных сочетаниях весьма перспективно для подавления нежелательной древесной растительности способом инъекции в смешанных насаждениях. The aim of the work was to improve the regulation of the composition and density of forest stands by injecting herbicides and their mixtures into the trunks of hardwood trees to increase silvicultural efficiency, reduce the chemical and toxic load on forest ecosystems. The objects of research were individual trees of gray alder and aspen of vegetative origin in the pole stage in mixed stands. As a result of the analysis of domestic and foreign literature on the problem, promising herbicides for study were selected – tornado (aqueous solution, 360 g/l glyphosate in the form of isopropylamine salt) and arbonal (water-soluble concentrate, 250 g/l imazapyr) and field experiments were laid with selected herbicides. In four field experiments, the biological effectiveness of the action of herbicides and their mixtures on gray alder and aspen trees in mixed plantations was determined. As a result, the high efficiency of the herbicide arbonal at doses of 0.08 and 0.16 ml/tree, as well as mixtures of tornado (0.12–0.25 ml/tree) + arbonal (0.06–0.08 ml/tree) was established on gray alder. According to the effect on aspen, the most effective was the use of tornado 0.20 ml/tree and 0.55 ml/tree), arbonal (0.16 ml/tree) and mixtures of tornado (0.20 ml/tree) + arbonal (0.08 ml/tree) and tornado (0.25 ml/tree) + arbonal (0.06 ml/tree). Alder gray showed greater resistance to the applied herbicides in the year of treatment, but we should expect an increase in the effect of herbicides in the next growing season. It has been established that the use of herbicides tornado and arbonal, as well as their mixtures in various combinations, is very promising for the suppression of unwanted woody vegetation by injection in mixed stands.

ПРОГНОСТИЧЕСКОЕ МОДЕЛИРОВАНИЕ ИНВАЗИОННЫХ И КЛИМАТИЧЕСКИ ОБУСЛОВЛЕННЫХ СЦЕНАРИЕВ ВСПЫШЕК ЧИСЛЕННОСТИ ВРЕДИТЕЛЕЙ

The climate change observed in the zone of boreal forests of the Holarctic since the end of the 20th century initiates the effect of expanding the boundaries of biological species ranges. Climate-driven invasive processes differ in dynamics. In some situations, there are population outbreaks of unwanted species. In addition to the climatic factor, an important aspect is the response of a biotic environment. Special methods are required to predict rapid invasions that can cause extreme changes. The reproductive potential of pests often turns out to be excessive due to warming climate and favorable conditions. Aggressive invasions often develop as oscillating processes that transform when the species adapts to the environment and fades when the autochthonous biota adapts to a new species. Not only new pests, but also the enemies of the main enemies of ordinary pests have become harmful invaders. Computational scenario models of invasions have been developed based on a logically expandable hybrid structure of equations that take into account delayed adaptation, which is manifested depending on climatic factors as an invasion outbreak develops. The scenarios indicate the series of peaks with fading activity after a primary outbreak and make it possible to evaluate the factors that cause repeated activity of a population after a depression when the invasion of a hyperparasite turns out to be essential.

A bioaugmentation strategy to recover methane production under sulfate-stressed conditions: Highlights on targeted sulfate-reducing bacteria and DIET-related species

A bioaugmentation strategy to recover methane production under sulfate-stressed conditions: Highlights on targeted sulfate-reducing bacteria and DIET-related species

Modeling and Analysis of Fractional Order Logistic Equation Incorporating Additive Allee Effect

This study investigates the logistic model of a single species incorporating the additive Allee effect using Caputo fractional order differential equations. The Allee effect describes a positive correlation between individual fitness and population density at low densities. Populations subjected to the strong Allee effect can move towards extinction when their population is below a critical level. This study calculates the threshold level of the population suffering from the strong Allee effect. Various published studies are showing that fractional order models are more appropriate for explaining real-world phenomena than ordinary integer-order systems; therefore, this study involves the use of the Caputo fractional order derivative. Single-species models have been extensively used in mathematical biology, such as insect control, optimal biological resource planning, epidemic avoidance and control, and cell growth regulation. This study can help save vulnerable species from extinction and eliminate unwanted species by subjecting them to a strong Allee effect using artificial strategies.

Understanding the different effects of fouling mechanisms on working and reference electrodes in fast-scan cyclic voltammetry for neurotransmitter detection.

Fast-scan cyclic voltammetry (FSCV) is a widely used technique for detecting neurotransmitters. However, electrode fouling can negatively impact its accuracy and sensitivity. Fouling refers to the accumulation of unwanted materials on the electrode surface, which can alter its electrochemical properties and reduce its sensitivity and selectivity. Fouling mechanisms can be broad and may include biofouling, the accumulation of biomolecules on the electrode surface, and chemical fouling, the deposition of unwanted chemical species. Despite individual studies discussing fouling effects on either the working electrode or the reference electrode, no comprehensive study has been conducted to compare the overall fouling effects on both electrodes in the context of FSCV. Here, we examined the effects of biofouling and chemical fouling on the carbon fiber micro-electrode (CFME) as the working electrode and the Ag/AgCl reference electrode with FSCV. Both fouling mechanisms significantly decreased the sensitivity and caused peak voltage shifts in the FSCV signal with the CFME, but not with the Ag/AgCl reference electrode. Interestingly, previous studies have reported peak voltage shifts in FSCV signals due to the fouling of Ag/AgCl electrodes after implantation in the brain. We noticed in a previous study that energy-dispersive spectroscopy (EDS) spectra showed increased sulfide ion concentration after implantation. We hypothesized that sulfide ions may be responsible for the peak voltage shift. To test this hypothesis, we added sulfide ions to the buffer solution, which decreased the open circuit potential of the Ag/AgCl electrode and caused a peak voltage shift in the FSCV voltammograms. Also, EDS analysis showed that sulfide ion concentration increased on the surface of the Ag/AgCl electrodes after 3 weeks of chronic implantation, necessitating consideration of sulfide ions as the fouling agent for the reference electrodes. Overall, our study provides important insights into the mechanisms of electrode fouling and its impact on FSCV measurements. These findings could inform the design of FSCV experiments, with the development of new strategies for improving the accuracy and reliability of FSCV measurements in vivo.

Life on the Move

What does the War on Terror have to teach us about the ongoing War on Invasive Species? Rooted in the author's personal experiences as an immigrant on a family farm in Virginia, this essay explores themes of language, mental frames, and violent conflict in novel ways that shed insight into the morality of the struggle to manage unwanted species.

Bird Boxes and Sparrow Traps: The Technological Regulation of Avian Life in the United States.

Only a few decades after its introduction to the United States in the mid-nineteenth century, the house sparrow was considered a pest that drove away native birds. Its downfall is representative of a story familiar to scholars of animals and technology who have studied the methods used to control or exclude unwanted species from both rural and urban areas. The case of the house sparrow, however, differs in a crucial respect: the birds made their homes in bird boxes, built technologies designed to attract avian species and bring them closer to humans. This article documents how bird boxes were used as tools to regulate avian life in the late nineteenth and early twentieth centuries in the United States and argues that they should be seen as a technology that mediates and regulates our relationship with nature by promoting or controlling certain aspects of living organisms.

Approaching single-species exclusion in mixed demersal trawl fisheries

Under a discard ban, mixed fisheries must often reduce catches of low-quota species to allow the continuation of fishing activities. This has led to the development of a range of bycatch reduction devices (BRDs) that aim to exploit morphological and behavioral differences among species to facilitate escape of unwanted catch from the fishing gear. However, the exclusion of unwanted species from the catch is often only possible with concomitant losses of other commercial catches. This is the case for the Nephrops (Nephrops norvegicus)-directed mixed demersal trawl fishery, where BRDs aiming at the reduction of catches of cod (Gadus morhua) often lead to considerable losses of other valuable species. In this study, we developed and tested a BRD aimed at exclusively reducing cod catches without affecting catches of Nephrops, flatfish and other roundfish. The design, a bottom escape window, exploits behavioral traits that set cod apart from other species. We collected absolute selectivity data using a paired gears approach and estimated the combined retention of the bottom escape window and a 90 mm diamond mesh codend. The results demonstrated a low total retention of cod (33%) in combination with high retentions of commercial catches of Nephrops (89%), haddock (Melanogrammus aeglefinus) (76%) and plaice (Pleuronectes platessa) (100%), for the populations encountered. This catch profile represents an important and novel achievement for Nephrops-directed mixed demersal fisheries. We compared the performance of this new BRD to one of the most used legal gears in this fishery (the SELTRA 270), demonstrated the new catch profile it can offer to the fishers, and discussed its management implications.

Lime application to condition soil to pH 11 controls growth of harmful vibrios and WSSV

Shrimp farming has been devastated by several diseases. Disease outbreaks can be prevented by optimising environmental conditions or by eliminating risks factors including carrier organisms. These can be achieved through proper pond preparation. One important step in pond preparation is the application of hydrated lime. This paper describes the effect of hydrated lime application to condition pond soil to pH 11 on the pond ecosystem, more specifically on soil pH and biota. The experiment was done using three 600 m2 brackish water ponds. After hydrated lime application, the wet soil pH on the 1st-8th day was significantly higher (P<0.05) compared to the pH before liming to pH 11, and flushing after flooding for 24 h. Soil pH of 11 was observed 24-48h after lime application. Moreover, unwanted species like crabs and fish were found dead. Liming to pH 11 negatively affects the counts of green vibrio colonies thereby decreasing the percentage of green vibrios (PGV). In another experiment, three 750m2 earthen ponds were used. The pond soils were previously positive for the Whitespot Syndrome Virus (WSSV), hydrated lime were applied to bring the pond soil pH to 11. After lime application, WSSV was not detected in the pond soils. Results showed that increasing the soil pH to ≥11 positively affects the pond ecosystem. Liming encourages the proliferation of yellow vibrios and the eradication of carrier species (i.e. crabs) as well as predators (i.e. fish) in the ponds. Furthermore, liming to pH 11 may also eradicate White spot virus from the pond sediment. To implement a 1-unit increase in wet pH, hydrated lime should be applied at 2T/ha.

High bycatch rate of the coral Cladocora caespitosa offsets the low discards ratio in Thermaikos Gulf gillnet fishery

While hanging nets may have fewer overall environmental impacts than towed gears, they still catch unwanted species and sizes, which are then discarded. Gillnets are one of the most common types of nets used in Mediterranean small-scale fisheries, with commercial catches and discards containing a diverse range of fish and invertebrate species. In this study, the catch profile of gillnets in the Thermaikos Gulf (NE Mediterranean) was analyzed with a focus on the discarding of species with unfavorable conservation status, such as the Mediterranean-endemic scleractinian coral Cladocora caespitosa, which is listed as endangered due to declining population sizes. Our survey was conducted over two seasons (May to October in 2020 and 2021) and included 69 fishing trials under realistic fishing conditions. In general, gillnets exhibited a relatively low discards ratio (17.2%; 7.1% when only fish were considered) and a low prevalence and capture intensity of endangered or threatened species; during the entire survey, only one chondrichthyan was captured (1 specimen of Raja radula), while only two out of 54 fish species were of vulnerable IUCN status. These advantages were offset in part by the high catchability of C. caespitosa colonies, which occurred in 61% of hauls and accounted for 53% of total invertebrate biomass and 30% of total discarded biomass. The likelihood of hauling living colonies of C. caespitosa was higher when fishing over known coral beds (81% vs. 43%), and the overall probability of hauling C. caespitosa in any state was 18% higher over coral beds, suggesting that gillnets frequently detach colonies from the seafloor, which are then dispersed over a larger area as fragments with probably low survival potential. Our findings highlight the importance of identifying C. caespitosa beds so that fishermen avoid setting their nets in these areas, provided that they are well-informed and educated about the ecological significance of this endemic, threatened, and ecologically important species.

Rich dynamics of a predator-prey system with state-dependent impulsive controls switching between two means

Rich dynamics of a predator-prey system with state-dependent impulsive controls switching between two means

A win–win between farmers and an apex predator: investigating the relationship between bald eagles and dairy farms

AbstractHuman–wildlife conflicts on farms and ranches are common and well‐documented, particularly with apex predators. Predation of livestock, for example, can result in serious economic burdens for farmers and can become threats to wildlife populations as farmers take action to eliminate or displace populations. Among apex predators, bald eagles (Haliaeetus leucocephalus) have received increased media attention in recent years due to conflicts with farmers across the United States. This raises challenges for both farmers and wildlife managers as eagle abundance continues to increase and natural prey resources decline. Interestingly, a recent study in northwestern Washington State reported high eagle activity on dairy farms in response to declines in salmon carcass availability, an important resource for wintering eagles across western North America. Despite the potential for human–wildlife conflict in these areas, little is known of the relationship between eagles and dairy farms. In this study, we investigated the extent of eagle activity on dairy farms and the relationship between eagles and dairy farmers using semistructured interviews with dairy farmers. We found that (1) eagles were attracted to dairy farms to feed primarily on cow afterbirth and calf carcasses, (2) responding farmers had no issue with the presence of eagles on their farms, and (3) many dairy farmers felt that eagles provided services to their farms. Of these services, the most recognized were scavenging of dairy farm byproducts and removal or deterrence of unwanted pest species. Increased eagle abundance on dairy farms and the subsidy of anthropogenic resources may also influence the ecological role of eagles as top predators in agroecosystems. Ultimately, farmers' decisions to provide anthropogenic resources have apparently mitigated human–eagle conflict while potentially reducing top–down pressures on other wild prey species. Farmers and wildlife managers may each benefit through cooperation in continuing to understand the intricacies of dairy farm–eagle relationships.