Eradication Of Species Research Articles

Did COVID-19 Lockdown Restrictions have an Impact on Biomass Burning Emissions in Sub-Saharan Africa?

Across Sub-Saharan Africa (SSA), biomass burning for land clearance, grazing management, and eradication of invasive plant species emit various pollutants into the atmosphere and thus affect air quality, human health, and microclimates. The seasonality of fire events generally follows that of rainfall. Since the outbreak of COVID-19 in Africa in February 2020, several countries have implemented lockdown regulations that restrict mobility, trade, and other socio-economic activities. It is not clear how the lockdown restrictions would affect wildfire spread, density, and emissions. This study sought to address this gap by analysing changes in Black Carbon (BC), smoke+polluted dust AOD, and Carbon monoxide (CO), as well as the burned area (BA) and fire density using multi-source data at periods consistent with lockdown restrictions. Generally, the results indicated an increase in emissions (CO, BC, smoke+polluted dust AOD) due to COVID-19 lockdown. Specifically, increases of 0.008 mol m–2 in CO and 20% in smoke+polluted dust AOD were observed in the SSA region during COVID-19 lockdown. The majority of emissions resulted from the burning of forest cover (FC), cultivated lands (CL), and shrublands (SL) due to escaped fires from agricultural activities. The BA and fire density were also higher in the COVID-19 year (2020) than the previous year (2019), which was suspected to be caused by the closure of or not fully operated fire authorities due to the COVID-19 lockdown. The increasing biomass burning emissions, as shown here, have important implications for air quality and public health.

A retrospective review of Achromobacter species and antibiotic treatments in patients with primary ciliary dyskinesia.

Objectives: Primary ciliary dyskinesia (PCD) is a rare congenital disease with defective mucociliary clearance causing frequent and often persistent pulmonary infections. Achromobacter species are opportunistic pathogens renowned for the difficulty of effective treatments and deteriorating effects on lung function. We aimed to describe the occurrence, treatment, and rate of successful eradication of Achromobacter species in patients with PCD. Methods: We retrospectively reviewed 18 years of historical microbiological samples and 10 years of electronic health records for PCD patients in Denmark. Results: We included 136 patients. Twenty-six patients had isolates of Achromobacter species. On average, 5% of the cohort had at least one annual isolate. Infections became persistent in 38% with a median length of 6.6 years leading to a significant number of antibiotic treatments. Resistance toward tobramycin and ciprofloxacin was prevalent. Overall, successful eradication was achieved in 62% of patients. We found the course of lung function significantly worse during persistent Achromobacter species infection than during the two preceding years, but not different to the course in unaffected age-matched controls. Conclusion The prevalence of Achromobacter species in patients with PCD is in line with what has been reported in cystic fibrosis and can occur transiently, intermittently, or develop into a serious persistent lung infection associated with long-term antibiotic treatment.

The potential negative impacts of the classical swine fever virus on wild boar population in Gifu prefecture, Japan.

There is a possibility that classical swine fever (CSF) virus outbreak has negative impacts on wild boar. To adequately manage native wild boar populations, wildlife managers need to gather the field data on wild boar and implement population management practices. We aimed to report the relative abundance index of wild boar before and after this outbreak. Our results showed that relative abundance index declined from 2017 (8.88 wild boars/100 trap days) to 2019 (2.03 wild boars/100 trap days), because of the negative impact of this virus and continuous culling programs. Although the eradication risk from the synergistic effect is low, wildlife managers need to consider the relationship between the trade-off between the risk of CSF and the conservation ecology risk of native species eradication.

Review of the reporting of ecological effects of rodent eradications on Australian and New Zealand islands

Island species are susceptible to invasive mammals because of their small populations, specialised habitats and reduced likelihood of recolonisation. For more than 50 years, invasive mammals have been eradicated from islands around the world. Despite the success of eradications, there are few publications in the primary literature detailing the ecological benefits and consequences of these eradications. Here we conduct a review of the published literature focussing on rodent eradications conducted on Australian and New Zealand islands and we evaluate the extent of reporting of non-target mortality and ecological monitoring following an eradication. A search of the Database of Island Invasive Species Eradications website identified that successful, whole-island rodent eradications were conducted on 66 Australian and 124 New Zealand islands in the period from 1964 to 2016. We found that non-target mortality was rarely ever reported (3% and 12% for eradications on Australian islands and New Zealand islands, respectively). Results of any quantitative ecological monitoring following eradications were published for only 10% of all successful rodent eradications on Australian islands and 19% of all eradications on New Zealand islands. There also has been no change in reporting of potential benefits and consequences of rodent eradications in Australia and New Zealand over the last few decades despite an increased awareness of the problem of under-reporting. We discuss the detailed benefits and consequences of these eradications in Australia and New Zealand and highlight the need to incorporate ecological monitoring into new projects to document benefits and consequences of eradications to inform future eradications.

The Role of Disinsection and Deratization in the Framework of Non-Specific Prophylaxis of Diseases among the Population in Natural Plague Foci in the Territory of the CIS Countries

Natural foci of plague – a particularly dangerous transmissible zoonotic disease – are widely spread across the world, including in the territory of Russia and a number of neighboring countries in Central Asia. Between 2000 and 2019, 28339 cases of plague were registered in 21 states around the world; lethality rates reached 8 %. Active plague manifestations are associated with the increase in the abundance of carriers and vectors of the disease, which increases the risk of human infection. Prophylactic measures against plague are aimed at prevention and eradication of epidemic foci; they incorporate a whole complex (system) of activities. Disinsection and deratization remain the most radical of them. Control of the numbers of carriers and vectors of plague involves decrement up to the levels at which epizooties will not develop, they are suppressed and liquidated. Currently in the Russian Federation and CIS countries, the focus is on the field and community disinsection when planning and performing exterminatory interventions. The decrease in the numbers of fleas – carriers and vectors of plague microbe – results in disruption of epizootic process and, consequently, in provision of epidemiological welfare as regards this dangerous disease. Insecticide treatments in natural biotopes are carried out using powder-like or aerosolized products, the class of pyrethroids, organophosphorous compounds and phenylpyrazoles by means of advanced equipment: knapsack dusters, power operated air blowers, and foggers. Within the boundaries of residential areas wet disinsection is performed with the help of spraying devices. Field deratization is allowed upon epidemiological grounds only, in localized territories of epizooties, within the boundaries of the settlements of plague infected carriers. Zinc phosphide- or anticoagulant-based bait products are used as rodenticides. Therewith, the eradication of valuable animal species, rare species of small mammals and endemic species is prohibited. Community deratization is always accompanied by the community disinsection. When planning and carrying out insecticide and rodenticide treatments the priority is given to the safety of handling the chemical preparations, to the exclusion of the negative effect on target animal species.

Calling behaviour in the invasive Asian house gecko (Hemidactylus frenatus) and implications for early detection

Abstract ContextAcoustic communication is common in some animal groups, with an underlying function typically associated with mating or territoriality. Resolving the function of calls is valuable both in terms of understanding the fundamental biology of the species and, potentially, for applied reasons such as detection. Early detection is a key step in exclusion and eradication of invasive species, and calling behaviour can be used in this regard. The Asian house gecko (Hemidactylus frenatus) is one of a minority of lizards that uses acoustic communication. However, despite how conspicuous the call is, its function remains poorly resolved. It is also one of the world’s most invasive species, with exclusion via early detection being the key form of control. AimsThe aim was to resolve calling patterns and underlying function of the loud, multiple-chirp call (‘chik, chik, chik…’) in H. frenatus, in the context of using the results for developing effective methods for detection of new and establishing populations. MethodsThe calls of wild H. frenatus were recorded to assess peaks in calling activity. Also, laboratory experiments were performed to determine which individuals call, what causes them to call and the degree of call variation among individuals. Key resultsAssessment of calling behaviour in the wild revealed greater calling activity in warmer months, and five- to 10-fold peaks in calling activity at sunset and 30min before sunrise. Laboratory experiments revealed that calls were uttered exclusively by males and primarily by adults (although juveniles can call). Males called more when they were paired with females as opposed to other males. Calls differed among geckos, including the expected negative correlation between dominant frequency and body size. ConclusionsThe results suggest that the multiple-chirp call functions as a territory or sexual broadcast by males, perhaps containing information such as body size. ImplicationsDetection success can be maximised by performing acoustic surveys (by human or machine) during the calling peaks at 30min before sunrise and at sunset, particularly during warm nights. However, these surveys will only be effective for detecting adult males. The results also suggest that good quality recordings could potentially be used to identify individual geckos.

Recent advances of quantitative modeling to support invasive species eradication on islands

AbstractThe eradication of invasive species from islands is an important part of managing these ecologically unique and at‐risk regions. Island eradications are complex projects and mathematical models play an important role in supporting efficient and transparent decision‐making. In this review, we cover the past applications of modeling to island eradications, which range from large‐scale prioritizations across groups of islands, to project‐level decision‐making tools. While quantitative models have been formulated and parameterized for a range of important problems, there are also critical research gaps. Many applications of quantitative modeling lack uncertainty analyses, and are therefore overconfident. Forecasting the ecosystem‐wide impacts of species eradications is still extremely challenging, despite recent progress in the field. Overall, the field of quantitative modeling is well‐developed for island eradication planning. Multiple practical modeling tools are available for, and are being applied to, a diverse suite of important decisions, and quantitative modeling is well placed to address pressing issues in the field.

Exotic Prey Facilitate Coexistence between Pumas and Culpeo Foxes in the Andes of Central Chile

Coexistence between species with similar ecological niches implies species must segregate along one or more niche axes to survive. Space, time, and trophic resources are regarded as the principal axes upon which species segregate. We examined segregation along these niche axes to determine mechanisms underlying coexistence between the two main predators, puma (Puma concolor) and culpeo foxes (Lycalopex culpaeus) in the Andes of Central Chile. We used occupancy modeling to examine space use and overlap, Kernel Density Estimation to determine temporal activity patterns and overlap, and analysis of prey remains in feces to assess diet breadth and similarity. We found high spatial overlap and positive associations between detection of the carnivores lending little support for spatial segregation. Similarly, we found high nocturnal, temporal overlap between pumas and foxes that matched peaks in activity of prey. In contrast, we found relatively low dietary overlap indicating niche segregation likely occurs along the dietary axis. The Puma diet was dominated by introduced, exotic hares and foxes appeared to shift away from hares to rabbits, small mammals, and seeds. Given that lagomorphs are the main dietary resource for pumas in particular, management decisions regarding the control or eradication of such exotic species could negatively affected puma survival.

Climate oscillation and the invasion of alien species influence the oceanic distribution of seabirds.

Spatial and temporal distribution of seabird transiting and foraging at sea is an important consideration for marine conservation planning. Using at‐sea observations of seabirds (n = 317), collected during the breeding season from 2012 to 2016, we built boosted regression tree (BRT) models to identify relationships between numerically dominant seabird species (red‐footed booby, brown noddy, white tern, and wedge‐tailed shearwater), geomorphology, oceanographic variability, and climate oscillation in the Chagos Archipelago. We documented positive relationships between red‐footed booby and wedge‐tailed shearwater abundance with the strength in the Indian Ocean Dipole, as represented by the Dipole Mode Index (6.7% and 23.7% contribution, respectively). The abundance of red‐footed boobies, brown noddies, and white terns declined abruptly with greater distance to island (17.6%, 34.1%, and 41.1% contribution, respectively). We further quantified the effects of proximity to rat‐free and rat‐invaded islands on seabird distribution at sea and identified breaking point distribution thresholds. We detected areas of increased abundance at sea and habitat use‐age under a scenario where rats are eradicated from invaded nearby islands and recolonized by seabirds. Following rat eradication, abundance at sea of red‐footed booby, brown noddy, and white terns increased by 14%, 17%, and 3%, respectively, with no important increase detected for shearwaters. Our results have implication for seabird conservation and island restoration. Climate oscillations may cause shifts in seabird distribution, possibly through changes in regional productivity and prey distribution. Invasive species eradications and subsequent island recolonization can lead to greater access for seabirds to areas at sea, due to increased foraging or transiting through, potentially leading to distribution gains and increased competition. Our approach predicting distribution after successful eradications enables anticipatory threat mitigation in these areas, minimizing competition between colonies and thereby maximizing the risk of success and the conservation impact of eradication programs.

Invasive vertebrate eradications on islands as a tool for implementing global Sustainable Development Goals

SummaryThe United Nations 2030 Agenda for Sustainable Development sets a framework of universal Sustainable Development Goals (SDGs) to address challenges to society and the planet. Island invasive species eradications have well-documented benefits that clearly align with biodiversity conservation-related SDGs, yet the value of this conservation action for socioeconomic benefits is less clear. We examine the potential for island invasive vertebrate eradications to have ecological and socioeconomic benefits. Specifically, we examine: (1) how SDGs may have been achieved through past eradications; and (2) how planned future eradications align with SDGs and associated targets. We found invasive vertebrate eradication to align with 13 SDGs and 42 associated targets encompassing marine and terrestrial biodiversity conservation, promotion of local and global partnerships, economic development, climate change mitigation, human health and sanitation and sustainable production and consumption. Past eradications on 794 islands aligned with a median of 17 targets (range 13–38) by island. Potential future eradications on 292 highly biodiverse islands could align with a median of 25 SDG targets (range 15–39) by island. This analysis enables the global community to explicitly describe the contributions that invasive vertebrate management on islands can make towards implementing the global sustainable development agenda.

Black Bullhead Removal from a Headwater Trout Stream in Southern California

AbstractThe introduction of invasive species has resulted in negative impacts to aquatic ecosystems and is cited as the second leading cause of fish extinctions. In the southwestern United States, low diversity and high levels of endemism increase the deleterious effects of these introductions. Near the southern edge of their range, the last remaining population of native Coastal Rainbow Trout Oncorhynchus mykiss irideus in San Diego County, California, inhabits the West Fork San Luis Rey River (WFSLRR). The nonnative Black Bullhead Ameiurus melas was discovered in the WFSLRR in 2007, elevating concern over this small population of Coastal Rainbow Trout. Preliminary surveys found that baited minnow traps set overnight were effective at capturing Black Bullhead; therefore, a removal project was initiated. Crew members set baited traps at the upstream end of the Coastal Rainbow Trout distribution in the evening (maximum = 72 traps/trip) and checked the traps the following morning. Four two‐night trips were completed in 2016, removing 1,315 Black Bullhead. The initial Black Bullhead population was estimated as 1,361 fish by a depletion function. Follow‐up surveys in 2017 and 2018 captured no Black Bullhead. Prolonged drought conditions in California during the removal effort may have concentrated the Black Bullhead into pools, facilitating this rare complete eradication of an invasive fish species.

Erythropodium caribaeorum (Duchassaing and Michelotti, 1860) (Cnidaria: Alcyonacea), an additional alien coral in the Southwestern Atlantic.

Invasive species may compromise biodiversity and ecosystem services, and represent a steadily growing concern for coastal marine ecosystems. The marine aquarium trade (MAT) is the source of some of the world's worst aquatic invasions, inflicting multimillion-dollar losses in infected regions. In the Southwestern Atlantic (SWA), two Indo-Pacific coral species were recently introduced as a result of the MAT and already dominate the substrate at the introduction site in Southeastern Brazil (Praia Vermelha, Angra dos Reis, Rio de Janeiro State). Herein, based on morphological and molecular evidence, we report a Caribbean native coral species likely introduced by the MAT in Praia Vermelha, Erythropodium caribaeorum (Duchassaing Michelotti 1860). While the eradication of coral species that already have a pest status in the SWA is unlikely, we propose that the eradication of the three species still contained to their introduction sites, including E. caribaeorum, is still feasible and depends on a rapid and integrated embracement of the task by core stakeholders. Priority actions for the regulation of MAT and hobbyism in Brazil are proposed.

Global ore trade is an important gateway for non‐native species: A case study of alien plants in Chinese ports

AbstractAimBiological invasion has become one of the most important environmental concerns in many countries, with considerable time, money and effort being spent in the prevention and eradication of invasive species. Since mineral ores tend to harbour seeds from the local plants, our aim was to study the non‐native plants collected in Chinese ports to understand the influence of global ore trade on biological invasion.LocationChina.MethodsWe surveyed 75 ore heaps across six types of ore in 22 Chinese port cities from 2010 to 2016 and collected 737 voucher specimens of non‐native plants, out of which 709 specimens were traced to the country of origin. Using the software Maxent, we evaluated the risk of invasion from these non‐native plants based on the global ore trade flow, traced their route and predicted the regions in China most vulnerable to invasion by these plants.ResultsOf the 407 non‐native plant species identified, most were from India, followed by Malaysia, Swaziland, Mexico, and Iran. Taxonomically, there were representations from 49 families, notably Fabaceae, Poaceae, Asteraceae and Solanaceae. The non‐native plant species were represented by varying number of species, from a single specimen to 179. Analysis of the invasion risk indicated that the entire coast of China was at high risk. Furthermore, two major potential introduction pathways were also identified, namely the Yangtze drainage basin and the land from the Gulf of Tonkin to Sichuan Basin.Main conclusionAn important pathway for the invasion of non‐native plants is the inadvertent transportation of seeds through global ore trade networks. Based on this study, we suggest greater monitoring and cooperation in the international ore trade for better management, and creating public awareness of the dangers of non‐native species to help minimize the risk of transporting non‐native plants by the global ore trade network.

Status of chemicals and aqua-drugs used for freshwater fish health management at Rangpur district of Bangladesh

In order to know the existing situation of different chemicals and aqua-drugs used for fish health management an investigation was conducted following a time frame of May, 2019 to October, 2019 at Rangpur district of Bangladesh. Data were collected from the randomly selected fish farmers, company representatives and chemical sellers through questionnaire interview, personal contact and Focus Group Discussion (FGD). Farmers were facing several water quality problems associated with different fish diseases. To overcome those obstacles they use variety of chemicals inclulding lime, salt, potassium permanganate, urea, TSP, phitkiri and copper sulphate. Farmers used different chemicals for various purposes like Aquapure, Biopond, Zeofresh, JV-zeolite, Zeorich, Megazeo plus, Geo-ren etc. for pond preparation and water quality management; Sumithion, Engreb, I-mec, Sanmarine etc. for eradication of unwanted species; Oxymax, Oxymore, Oxylife, Aci-ox, Oxyrich, Oxy-aqua, Oxyren etc. to increase oxygen concentration and Gasonil, Gastrap, Bioaqua-50, Gasonex, Metrix, Pondkleen etc. for reducing harmful gases in pond water. Used disinfectants like Timsen, Virex, Polgard+, , Micronil etc.; antibiotics include Renamycin, Eskamycin, Bactitab, Cotrim vet bolus, Chemycin, Aquamycin etc.; Aqua photo, Safegut, Biomax, Profs, Pond care etc. were the used probiotics where various growth promoters include Panvit aqua, Nutrigel, Aquazyme, Spa gelly, Charger gel etc. Some problems were reported regarding the use of chemicals such as their indiscriminate use, method of application, time of application and inappropriate doses.
 Asian J. Med. Biol. Res. June 2020, 6(2): 283-293

Abundance, distribution and breeding success of the endemic Gough Island Finch Rowettia goughensis between 2009 and 2018

ABSTRACT The impacts of invasive house mice Mus musculus have received increasing attention on islands where mice are the only invasive rodent species. On Gough Island, the impact of mice on seabirds has increased over the past decade, but the current population status of the Critically Endangered Gough Finch Rowettia goughensis is uncertain. Based on nest monitoring at high elevation sites in 2009 (n = 37) and 2018 (n = 45), we found mean nest survival of 55% in both years and a fecundity of 1.31 ± 0.69 fledglings per pair in 2018. Density estimates from territory mapping in 2009 and 2018 were similar to past estimates and indicated little change in upland habitat. Density estimates from line transect distance sampling surveys around the island from 2018 to 2020 revealed higher densities in moorland (55.4 birds/km2) and wet heath (29.5 birds/km2) habitats, compared to coastal tussock (10.9 birds/km2) and lowland fern bush habitat (2.6 birds/km2). Extrapolating these habitat-specific densities across the island indicates a global population of Gough Finches in 2020 of 1917 individuals (95% CI: 1550–2500). Future population surveys using the same design could detect population changes of 40% or more. Our population estimate provides an important baseline for future monitoring following the planned eradication of house mice from Gough Island in 2021. However, we highlight that greater monitoring effort may be needed to increase the power to detect smaller population changes after an invasive species eradication.

Occupancy dynamics of rare cyprinids after invasive fish eradication

Abstract The eradication of invasive species is a management strategy implemented to eliminate adverse impacts of invaders on native species communities. After eradications, follow‐up studies are done to confirm eradication of the invasive species and the short‐term recovery of the native species, but long‐term monitoring to confirm full population recovery and stability is often not completed. In this study, long‐term monitoring of native fishes was carried out over 5 years after the eradication of an invasive fish from the Rondegat River, South Africa. Forty‐six sites distributed along four river sections were sampled for presence/absence using underwater cameras and snorkel surveys. Density data were collected by snorkel surveys. Using multi‐season occupancy models, the annual probability of colonization and local extinction of the native fishes and annual rate of change in occupancy along the river were estimated. Changes in native fish densities across time and across the control and treatment sections were analysed using Kruskal–Wallis analysis, followed by Dunn's post‐hoc test. Probability of colonization and local extinction differed for each native fish species and may have been affected by extrinsic factors, such as rainfall, and intrinsic density‐dependent factors, hypothesized from the density data. The occupancy rates of change revealed that the two Near Threatened fish species have reached an occupancy dynamic equilibrium but the Endangered fish has not, suggesting that other conservation efforts may be needed. Long‐term monitoring of native fishes after an eradication programme has confirmed the successful removal of the invader and the recovery and stability of the community. However, successful eradication was not sufficient for full recovery of all species; additional conservation management strategies are needed to secure the population stability and persistence of endangered fishes. We recommend that eradication programmes, regardless of locality, should employ long‐term monitoring to ensure full recovery of a native fish community.

Invasive bivalve establishment as a secondary effect of eradication-focused nuisance aquatic plant management

Holbrook DL, Schad AN, Dick GO, Dodd LL, Kennedy JH. 2020. Invasive bivalve establishment as a secondary effect of eradication-focused nuisance aquatic plant management. Lake Reserv Manage. 36:423–431. We evaluated changes in aquatic vegetation cover and community structure in hydrilla (Hydrilla verticillata)-infested constructed experimental ponds after applying the management tools of triploid grass carp (Ctenopharyngodon idella) stockings, herbicide applications, and native macrophyte planting (emergent, floating-leaved, and submersed species). In ponds where aquatic vegetation was most reduced due to management (herbicide and >72 grass carp per vegetated hectare stockings), a secondary infestation of the invasive bivalve (Asian clam or Corbicula fluminea) was observed. Asian clam abundances were analyzed in relation to grass carp stocking densities (0, 40–42, 72–81, and 110–129 per vegetated hectare), depth, and changes in native and invasive vegetation community structure and cover. Data analyses showed inverse relationships of Asian clam abundances to vegetation cover and to depth, as well as a synergetic relationship with grass carp stocking density. Implications of this research indicate that when a nuisance aquatic plant management strategy is focused on full or near eradication of a target species, inevitable damage to native species that might otherwise preserve beneficial ecological components may result in secondary issues, such as the expansion of additional invasive species due to opening of habitats. Excessive control efforts of a targeted nuisance plant species, and the results here highlight potential unintended consequences of over management of natural resources.

Everyday Ecocide, Toxic Dwelling, and the Inability to Mourn

Abstract In responding to the spatiotemporally specific geographies of extinction charted in the articles in this special section, this article reflects on the sociocultural factors that inform the ways in which extinction is framed and impede recognition of the enormity of the anthropogenic extinction event in which we are all bound. This article argues that we are living in an era of ecocide, where the degradation of biodiversity and eradication of species go hand-in-hand with the degradation and eradication of nonmodern culture and identity, and it explores some possible reasons why modern society is failing to respond to impending crisis. Fine-grained stories of spatiotemporally specific geographies of extinction can help to counter the logic of colonization and bring everyday ecocide into view. For the particular multispecies communities they concern, they can also feed into the creation of ritual practices of penitential mourning in ways that enable a collective grieving process poised to activate an ecosocial transformation. The authors consider the implications of grief and mourning—and of not mourning—in what can be seen as not only a terrible time but also the end of (lived) time. They conclude with some reflections of local acts of resistance, witnessing, and narrative.

Development of Electrofishing for Fisheries Management

Electrofishing, broadly defined as the use of electricity to capture or control fish, was envisioned in an 1863 British patent application by Isham Baggs. Not until the 1920s, when large, stationary generators were available, did electrofishing applications (i.e., fish barriers) begin. After World War II, applications of electrofishing for fisheries management accelerated in diversity and portability. As the American Fisheries Society celebrates 150 years of dedication to aquatic resource conservation, our aim is to document the development of electrofishing for fisheries management in North America during the same period. Major management objectives comprise the topics in our article. While electrofishing has become a staple in fisheries management for conducting a wide range of applications such as population assessment and eradication of nuisance species, electrofishing use and equipment has evolved, particularly in response to human safety and fish welfare.

Using YY supermales to destabilize invasive fish populations

A plausible biocontrol strategy for the eradication of invasive species involves augmenting wild populations with genetically modified supermales. Supermales contain double YY chromosomes. When they are augmented into a wild population, destabilization and eventual extinction occurs over time due to a strongly skewed gender ratio towards males. Here, we employ a mathematical model that considers an Allee effect, but we have discovered through simulation that the presence of supermales leads to an increase in the minimal number of females needed for survival at a value higher than the mathematically defined Allee effect. Using this effect, we focus our research on exploring the sensitivity of the optimized supply rate of supermale fish to the initial gender ratio and density of the wild populations. We find that the eradication strategy with optimized supply rate of supermales can be determined with knowledge of reproductive rate and survival fitness of supermale fish.