scholarly journals Environmental DNA detection of endangered and invasive species in Kejimkujik National Park and Historic Site

Genome ◽  
2020 ◽  
Author(s):  
Tzitziki Loeza-Quintana ◽  
Steven Crookes ◽  
Pei Yuan Li ◽  
Darrin P Reid ◽  
Matthew Smith ◽  
...  

The use of environmental DNA (eDNA) allows the early detection of aquatic species at low densities (e.g. elusive and invasive species), which otherwise could be challenging to monitor using conventional techniques. Here, we assess the ability of eDNA sampling to detect the presence/absence of one species-at-risk (Blanding’s Turtle) and two invasive species (Chain Pickerel and Smallmouth Bass) in Kejimkujik National Park and National Historic site, Nova Scotia, where the aquatic system is highly acidic and rich in organic compounds. Five replicates of 1L water samples were taken per sampling site. Water filtration and eDNA extractions were performed on-site, while qPCR reactions were performed in the laboratory using species-specific assays. Samples were treated with an inhibition removal kit and analyzed pre- and post-inhibition removal. Despite the low pH and PCR inhibitors in water samples, our results showed positive eDNA detections in almost all expected positive sites (except in one site for Blanding’s Turtle). Detections of the target species were also observed at sites where their presence was previously unknown. Our study supports the advantage of eDNA to monitor species at low densities, revealing new distributions or recently invaded areas. We also demonstrate how eDNA can directly instruct management strategies in Kejimkujik.

2017 ◽  
Vol 68 (7) ◽  
pp. 1292 ◽  
Author(s):  
Mathew Davis ◽  
Chris McCarthy ◽  
Karen Beazley

Recent research has highlighted the need for invasive species risk assessments that consider multiple factors, such as habitat suitability and life history. With invasive species encroaching on the boundary of Kejimkujik National Park and National Historic Site (Kejimkujik), Canada, there is concern surrounding the potential ecological effects on the Park’s freshwater ecosystems. Herein we present a multifactor risk analysis for the risks of introduction of two invasive species, smallmouth bass and chain pickerel. Methods included computer-based analysis of cost–distance and habitat suitability, and a literature-based review of management techniques. Smallmouth bass were found to have a high risk of establishment and consequent ecological effects in Kejimkujik. Although chain pickerel can also negatively affect aquatic communities, their separation from the Park’s primary watershed and low dispersal ability resulted in lower levels of risk. Four recommendations were developed following a review of management techniques: (1) containment of the source population for smallmouth bass; (2) public education, outreach and communication; (3) monitoring and rapid response upon detection; and (4) collaboration with other parties. Although the present study focused on Kejimkujik, similar challenges for invasive freshwater fish assessment and mitigation exist elsewhere, and our methods may prove illustrative for researchers and managers working under similar conditions.


Author(s):  
Hiroki Mizumoto ◽  
Osamu Kishida ◽  
Kotaro Takai ◽  
Naru Matsuura ◽  
Hitoshi Araki

AbstractUnderstanding the distribution of invasive species and their reproductive area is crucial for their managements after invasion. While catch and observation surveys are still embraced, environmental DNA (eDNA) has been increasingly utilized as an efficient tool for identifying these species in the wild. In this study, we developed a Bufo-specific eDNA assay for detecting an invasive, toxic, and terrestrial toad species Bufo japonicus formosus in Hokkaido, Japan, and applied it to their reproductive area at watershed scale. The eDNA assay was field-validated in ponds where B. japonicus were observed, as well as in rivers downstream of the reproductive ponds. Thus, the assay provided us an opportunity to screen watersheds that include their reproductive area by collecting downstream water samples. Applying it to the Ishikari river basin, the largest river basin in Hokkaido (c.a., 14,330 km2), we detected toad eDNA at 32 out of 73 sampling sites. They are composed of eleven sites with species observation records nearby (all the sites with observation records within a 500 m radius) and 21 sites without such records. And those eDNA detections were from twelve out of 31 river systems in the entire river basin. A Bayesian, multiscale occupancy model supported high eDNA detectability among those sites. These results suggest that the eDNA assay can efficiently estimate the presence of reproductive area of the terrestrial toad even from a distant downstream of the watershed, and that it provides a powerful means of detecting new reproductive area and monitoring further spread of invasive species.


2021 ◽  
Vol 8 ◽  
Author(s):  
Iveta Matejusova ◽  
Jennifer Graham ◽  
Fiona Bland ◽  
Jean-Pierre Lacaze ◽  
Guillaume Herman ◽  
...  

The presence and diversity of marine non-native species, the number of new invasions, and the impact on native communities and habitats are important metrics used to assess the health of marine ecosystems. Monitoring for marine non-native species, using traditional approaches such as rapid assessment surveys (RASs), requires taxonomic expertise and may still fail to detect rare or inconspicuous species. This study reports a validation process for a quantitative PCR (qPCR) assay based on the cytochrome oxidase 1 gene, designed to detect highly invasive tunicate Didemnum vexillum by targeting environmental DNA (eDNA) present in water samples. The D. vexillum qPCR assay showed high sensitivity, with the threshold limit of detection (LOD) and modeled LOD3 (based on triplicate qPCR reactions) estimated as 9.187 and 1.117 copies reaction–1, respectively and the limit of quantification (LOQ) was calculated as 18 copies reaction–1. Analyses of water samples collected from selected Pacific oyster farms and recreational marinas in Scotland showed 100% concordance between the historical data on presence of D. vexillum from RASs and detection of D. vexillum eDNA. Consistency of detection of D. vexillum eDNA among different sampling points within each infected sampling site varied, ranging between 100% positive throughout the site to some sampling points testing “negative” or only as “suspected” for D. vexillum. Sites with lower within-site detection consistency included sites with a low density of D. vexillum as reported by RASs or were sites undergoing D. vexillum management. The present pilot monitoring program demonstrates the potential to generate important data on presence of D. vexillum. This program will be scaled up across large geographic regions and used in the first instance to focus and target the traditional RASs to D. vexillum eDNA-positive sites in a cost-effective way, with an aim to verify the species presence by visual observation and direct Sanger sequencing of positive qPCR products.


2019 ◽  
Vol 22 (2) ◽  
pp. 617-626 ◽  
Author(s):  
Colleen Kamoroff ◽  
Ninette Daniele ◽  
Robert L. Grasso ◽  
Rebecca Rising ◽  
Travis Espinoza ◽  
...  

Abstract Invasive alien species are a major threat to freshwater ecosystems, and American bullfrogs are among the world’s 100 most prominent aquatic invasive species causing negative direct and indirect effect on native aquatic fauna worldwide. Bullfrogs were intentionally introduced into Yosemite Valley, Yosemite National Park in the 1950s where they became well established in the subsequent years. Starting in 2005, the National Park Service (NPS) began bullfrog removal, targeting various life stages using hand, net, and spear techniques. Starting in 2015, the NPS conducted environmental DNA (eDNA) surveys and deployed audio recordings devices to ensure adequate detection of bullfrogs. During the first year of cencerted effort in the Valley in 2005, the NPS removed 86% of all recorded bullfrog. The subsequent decade was spent searching for individuals with lower return on effort. In 2012, the NPS removed the last observed signs of bullfrog breeding, and the last observed bullfrog in 2019. Following removal of the breeding bullfrog population, the NPS began restoration projects for species of special concern. The NPS introduced the federally threatened California red-legged frogs (Rana draytonii) into Yosemite Valley beginning in 2016. This is the first published successful eradication of bullfrogs on a landscape level. National Parks and Monuments often provide refuges for imperiled wildlife and should be managed to remove invasive species. Our work highlights effective bullfrog removal is obtainable and can lead to local recovery of endangered species.


2021 ◽  
Author(s):  
Hiroki Mizumoto ◽  
Osamu Kishida ◽  
Kotaro Takai ◽  
Hitoshi Araki

Abstract Understanding the distribution of invasive species and their reproductive area is crucial for their managements after invasion. While catch and observation surveys are still embraced, environmental DNA (eDNA) has been increasingly utilized as an efficient tool for identifying these species in the wild. In this study, we developed an eDNA detection system for an invasive, toxic, and terrestrial toad species Bufo japonicus in Hokkaido, Japan, and applied it to their reproductive area at watershed scale. We found that our system successfully detected their eDNA not only in ponds where their larvae were observed, but also in rivers downstream of the reproductive ponds. Thus, the system provided us an opportunity to estimate watersheds that include their reproductive area by collecting downstream water samples. Applying it to the Ishikari river basin, the largest river basin in Hokkaido (c.a., 14,330 km2), we detected their eDNA at 32 out of 73 river sampling sites. They are composed of eleven sites with species observation records nearby (all the sites with observation records within a 500 m radius) and21 sites without such records. And those eDNA detections were from 14 out of 31 river systems, and they were widespread across the river basin. These results suggest that the eDNA detection system can efficiently estimate the presence of reproductive area of the terrestrial toad even from a distant downstream of the watershed, and that it provides a powerful means of detecting new reproductive area and monitoring further spread of invasive species.


2021 ◽  
Author(s):  
Ismail Maqbul ◽  
Farrahdiba Yossan Fahrezi ◽  
Ersya Nurul A Bakhri ◽  
Indri Verawati ◽  
Lalu M Iqbal Sani ◽  
...  

Abstract Indonesia, as a country having a unique sea lane known as the Indonesian Archipelagic Sea Lanes (ASLs), has become one of the busiest countries in the world with varied shipping activities. These actions have the ability to facilitate the transmission of species (bio-invasion). Until recently, the number of global introduced species has increased, with negative consequences for environment and the economy. Environmental DNA (eDNA) approaches for detecting the presence of invasive species are currently receiving a lot of interest as a broad approach method in ecological research. As a result, the study used the eDNA technique to compare the quantity and variety of introduced species from the Cnidaria and Porifera Phyla, as well as to characterize their invasiveness status and possible presence in the waters of Jakarta Bay. Based on data from the inside Zone of National Park (ZI) and Outside Zone of National Park (ZO), the biological community composition, richness, and diversity were assessed (ZO). The mBrave workflow generated a total of 14,275 reads from high-throughput sequencing of amplicons from two zones, with 8,917 reads in ZI and 5,358 reads in ZO. Blackfordia virginica , Cordylophora caspia , and Ectopleura crocea were among the imported species included in the invasive category, with E. crocea having the highest abundance and being detected in both zones, with a total of 1300 reads, consisting of 1253 reads in ZI and 47 reads in ZO. Based on the findings, the eDNA methodology can be used as a biomonitoring and conservation method for invasive species.


2009 ◽  
Vol 66 (9) ◽  
pp. 1532-1545 ◽  
Author(s):  
Brianna Wyn ◽  
Karen A. Kidd ◽  
Neil M. Burgess ◽  
R. Allen Curry

Mercury (Hg) concentrations in fish from acidic lakes (pH < 6.0) are typically elevated above those from near-neutral systems. It is unknown whether high biomagnification rates through the supporting food web can explain elevated Hg concentrations in top predators from low pH lakes. To investigate this, we collected yellow perch ( Perca flavescens ), brown bullhead ( Ameiurus nebulosus ), banded killifish ( Fundulus diaphanous ), golden shiner ( Notemigonus crysoleucas ), and littoral and pelagic invertebrates from four acidic lakes in Kejimkujik National Park and Historic Site (KNPNHS), Nova Scotia, Canada, and analyzed them for total Hg and methyl Hg (MeHg), and δ13C and δ15N to determine sources of energy and trophic position, respectively. Mercury biomagnification rates (slopes of log Hg versus δ15N) varied significantly among the four lakes but did not explain the among-lake differences in perch Hg; these slopes were also within the range published for near-neutral systems. Rather, Hg concentrations in yellow perch (i.e., predatory fish) in KNPNHS were higher in lakes with higher MeHg in lower-trophic-level organisms and suggest that processes influencing Hg uptake at the base of the food web are more important than rates of food web biomagnification for understanding the variation in concentrations of this contaminant among top predators.


1999 ◽  
Vol 77 (10) ◽  
pp. 1609-1614 ◽  
Author(s):  
K Lorraine Standing ◽  
Thomas B Herman ◽  
Ian P Morrison

This study was conducted to obtain accurate information on the reproductive ecology of the threatened population of Blanding's turtle (Emydoidea blandingii) in Nova Scotia. In 1994, 1995, and 1996, beaches and roadways in Kejimkujik National Park were surveyed for nesting turtles; all nests observed were covered with wire-screen cages to prevent predation and facilitate the collection of data on incubation and nest success. Nesting lasted from mid-June until early July. In each year, 80% of nesting occurred during a 10-day period in the third and fourth weeks of June. Turtles nested in the evening and predominantly on lakeshore cobble beaches. Site fidelity is high in this population: 73.3% of multiparous females returned to nest on the same beach in all years. No female produced more than one clutch per season, and most females (67.9%) nested less than annually. Mean clutch size was 10.6 eggs. Hatchlings emerge in September and October. Incubation times ranged from 80 to 128 days (mean = 94 days, SD = 11.7 days; n = 26 nests). In 1994 and 1995, most protected nests were productive; that is, 76.4 and 93.3% of protected nests produced at least one live hatchling in 1994 and 1995, respectively. In 1996, only 18.1% of protected nests were productive. Between 50 and 75% of productive clutches contained unhatched eggs and, on average, between 1.0 and 1.2 eggs failed per productive clutch. Total annual egg failure ranged from 26.5 to 94%. In the absence of nest predation, lower temperatures during incubation and nest flooding appear to be major cause of egg failure in this population. More effective means of reducing nest failure and bolstering recruitment must be implemented if efforts to aid the recovery of this threatened population of Blanding's turtle are to be successful.


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