Threats to Indigenous Biota from Introduced Species on the Bonin Islands, Southern Japan

2008 ◽  
Vol 3 (3) ◽  
pp. 174-186 ◽  
Author(s):  
Kazuto Kawakami ◽  

High endemism has evolved on the Bonin Islands, a group of oceanic islands in the northwestern Pacific, due to a disharmonic, unique biota. However, human settlements have caused extensive deforestation and the introduction of invasive species over the last 200 years. Insular populations are vulnerable to the devastating effects of introduced predators, competitors, and diseases, because they have evolved in the absence of such factors. Introduced species (e.g., goats, cats, black rats, green anole lizards, invasive plants, and predatory flatworms) have caused population declines and the extinction of indigenous species through direct and indirect effects. Unpredictable events often occur within these food webs. Clearly, efforts must be made to control these introduced populations, and to that end, attempts to eliminate certain species (e.g., goats and rats) have begun. However, some invasive species cannot be completely eradicated from their ranges because of their wide distributions and high population densities. In such cases, these species must be confined to their current ranges, which, for the primary invasive species, is mainly limited to two inhabited islands. Problematically, some introduced species have become essential components of the current ecosystem due to long-term naturalization, and their elimination may cause decreases in native species. Thus, the construction of sustainable ecosystems that include both native and introduced species is a realistic goal of current conservation efforts.

2010 ◽  
Vol 26 (3) ◽  
pp. 347-350 ◽  
Author(s):  
Jannie Fries Linnebjerg ◽  
Dennis M. Hansen ◽  
Nancy Bunbury ◽  
Jens M. Olesen

Disruption of ecosystems is one of the biggest threats posed by invasive species (Mack et al. 2000). Thus, one of the most important challenges is to understand the impact of exotic species on native species and habitats (e.g. Jones 2008). The probability that entire ‘invasive communities’ will develop increases as more species establish in new areas (Bourgeois et al. 2005). For example, introduced species may act in concert, facilitating one another's invasion, and increasing the likelihood of successful establishment, spread and impact. Simberloff & Von Holle (1999) introduced the term ‘invasional meltdown’ for this process, which has received widespread attention since (e.g. O'Dowd 2003, Richardson et al. 2000, Simberloff 2006). Positive interactions among introduced species are relatively common, but few have been studied in detail (Traveset & Richardson 2006). Examples include introduced insects and birds that pollinate and disperse exotic plants, thereby facilitating the spread of these species into non-invaded habitats (Goulson 2003, Mandon-Dalger et al. 2004, Simberloff & Von Holle 1999). From a more general ecological perspective, the study of interactions involving introduced and invasive species can contribute to our knowledge of ecological processes – for example, community assembly and indirect interactions.


2021 ◽  
Vol 4 ◽  
Author(s):  
Emily Chen

Introduction Aquatic Invasive Species (AIS) are a growing concern for global biodiversity as humans continue to accelerate the transport of non-indigenous species beyond their natural range. These species may possess traits that allow them to thrive in new environmental conditions such as non-selective feeding and high reproductive output, causing ecological harm through competition with native species for limited local resources. Consequently, environmental DNA (eDNA) has come to the forefront of AIS management in recent years as a promising method to detect or monitor invasive species using rapid and non-invasive sampling to complement traditional surveying. As eDNA’s potential is explored and beginning to be adopted for a variety of applications around the world, it is increasingly important to synthesize the trends in field and laboratory protocols from different working groups to establish guidelines that will allow greater comparability between studies and improve experimental design. Methodology and Results This meta-analytic study collated and reviewed information from previously published eDNA studies that targeted AIS in freshwater and marine environments to recognize current patterns in sampling techniques, laboratory protocols, and potential geographic or taxonomic biases. A total of 492 records from 192 full-text articles were used in the analysis, composed of 408 species-specific and 84 metabarcoding records. With regards to sampling procedures, many studies were not explicit enough for true replicability, lacking critical information such as the volume of filtered water and details of storage conditions. There was no observable trend for eDNA extraction methods in either species-specific or metabarcoding approaches, with choice of extraction method being mostly arbitrary among laboratories as well as influenced by the recent emergence of dedicated commercial kits . Discussion This analysis revealed a wide variety of choices for collecting and processing eDNA samples, so it is recommended that there should be some sort of standardized workflow diagram or decision tree for every stage of the experimental design in order for researchers to determine what approaches best meet their research objectives. There is also a clear need for improving metadata reporting guidelines; although the relevance of some criteria depends on the goals and limitations of specific projects, there should be a standardized minimum set of parameters to be reported for each eDNA study, from environmental variables to decontamination practices to PCR conditions. This will increase consistency and transparency through all stages of eDNA research, which is key to collectively improving methodologies and moving forward in this field.


2011 ◽  
Vol 57 (5) ◽  
pp. 613-624 ◽  
Author(s):  
Judith S. Weis

Abstract This article reviews biological invasions in which predation (or its absence) plays a major role in the success of the invader. Examples are described in which the invader out-competes native species for the same food, and cases in which the invader consumes valued native species. In many instances, better predator avoidance by the invasive species or the absence of predators in the new habitat contributes to the success of the invaders; in other cases native or introduced predators appear to be able to keep the invasive species in check. A relatively new management approach in the US is the idea of adding another trophic level – to have humans act as the predators and consume the invasive species. This approach is being utilized in Florida and throughout the Caribbean against the lionfish, but could be extended to other fishes, as well as to various invasive crustaceans and mollusks. This idea is controversial, and current regulations prohibiting the possession of individuals of the invasive species (e.g., mitten crabs or snakefish) would preclude the development of a fishery for them.


Zootaxa ◽  
2020 ◽  
Vol 4852 (1) ◽  
pp. 145-150
Author(s):  
AKILA ABESINGHE ◽  
HIRANYA SUDASINGHE ◽  
ANJALIE AMARASINGHE ◽  
FAZLA FAREED ◽  
THARANI SENAVIRATHNA ◽  
...  

Invasive alien species (IAS) are a major threat to biodiversity and have contributed to population declines in native species worldwide (Vilà et al. 2011; Gurevitch & Padilla 2004). IUCN’s Invasive Species Specialist Group lists some 80 invasive or potentially invasive species in Sri Lanka, which is part of a global biodiversity hotspot (Myers et al. 2000; Marambe et al. 2011). The major release of aquatic IAS on the island are routed through the ornamental-fish industry (Marambe et al. 2011; Sudasinghe 2016), though a minority represents deliberate, if unplanned, introductions by governmental and non-governmental agencies (Marambe et al. 2011). 


Parasitology ◽  
2011 ◽  
Vol 138 (13) ◽  
pp. 1778-1792 ◽  
Author(s):  
O. VERNEAU ◽  
C. PALACIOS ◽  
T. PLATT ◽  
M. ALDAY ◽  
E. BILLARD ◽  
...  

SUMMARYOne of the major threats to biodiversity involves biological invasions with direct consequences on the stability of ecosystems. In this context, the role of parasites is not negligible as it may enhance the success of invaders. The red-eared slider, Trachemys scripta elegans, has been globally considered among the worst invasive species. Since its introduction through the pet trade, T. s. elegans is now widespread and represents a threat for indigenous species. Because T. s. elegans coexists with Emys orbicularis and Mauremys leprosa in Europe, it has been suggested it may compete with the native turtle species and transmit pathogens. We examined parasite transfer from American captive to the two native species that co-exist in artificial pools of a Turtle Farm in France. As model parasite species we used platyhelminth worms of the family Polystomatidae (Monogenea) because polystomes have been described from American turtles in their native range. Phylogenetic relationships among polystomes parasitizing chelonian host species that are geographically widespread show patterns of diversification more complex than expected. Using DNA barcoding to identify species from adult and/or polystome eggs, several cases of host switching from exotic to indigenous individuals were illustrated, corroborating that parasite transmission is important when considering the pet trade and in reintroduction programmes to reinforce wild populations of indigenous species.


2021 ◽  
Author(s):  
Adel KACIMI ◽  
Abderrahmane BOUDA ◽  
Bilel BENSARI ◽  
Nour El Islam BACHARI ◽  
Fouzia HOUMA

Abstract Biofouling of ship hulls is considered as one of the oldest vectors for the transfer of aquatic invasive species. However, the introduction of non-native species by ballast water has received much more research attention. In this study, an alternative approach to dealing with biofouling was proposed for the port of Arzew, based on ship characteristics and transit routes. The strategy consisted of calculation of the surface area of biofouling of all ships calling at the port of Arzew during the period (2013–2016), to which was added spatial modeling using a Geographic Information System to highlight the most relevant information. We identified the areas that represented a high risk of species introduction according to their respective ecoregions of origin; those areas that constituted a minor risk, the type of ship that most likely promotes the establishment of non-native species by comparing the environmental similarity of the ecoregions assigned to the different ships with the environmental characteristics of the port of Arzew obtained by satellite imagery. The study showed that over a period of four years, 5,733 ships called at the port of Arzew, accumulating a total surface area of 35 million square meters. These results can be used for invasive species management purposes; such as: the application of specific regulations on ships of a certain tonnage that most promote the transfer of non-indigenous species, as well as their ecoregions of origin that present a great environmental similarity with the western Mediterranean, in order to minimize the transfer of aquatic invasive species.


2018 ◽  
Vol 2 ◽  
pp. e24930
Author(s):  
Mark Wetter

North America’s Great Lakes contain 21% of the planet’s fresh water, and their protection is a matter of national security to both the USA & Canada. One of the greatest threats to the health of this unparalleled natural resource is invasion by non-indigenous species, several of which already have had catastrophic impacts on property values, the fisheries, shipping, and tourism industries, and continue to threaten the survival of native species and wetland ecosystems. The Great Lakes Invasives Network is a consortium (20 institutions) of herbaria and zoology museums from among the Great Lakes states of Minnesota, Wisconsin, Illinois, Indiana, Michigan, Ohio, and New York created to better document the occurrence of selected non-indigenous species and their congeners in space and time by imaging and providing online access to the information on the specimens of the critical organisms. The list of non-indigenous species (1 alga, 42 vascular plants, 22 fish, and 13 mollusks) to be digitized was generated by conducting a query of all fish, plants, algae, and mollusks present in the database of GLANSIS – the Great Lakes Aquatic Nonindigenous Species Information System – maintained by the National Oceanic and Atmospheric Administration (NOAA). The network consists of collections at 20 institutions, including 4 of the 10 largest herbaria in North America, each of which curates 1-7 million specimens (NY, F, MICH, and WIS). Eight of the nation’s largest zoology museums are also represented, several of which (e.g., Ohio State and U of Minnesota) are internationally recognized for their fish and mollusk collections. Each genus includes at least one species that is considered a Great Lakes non-indigenous taxon – several have many, whereas others have congeners on “watchlists”, meaning that they have not arrived in the Great Lakes Basin yet, but have the potential to do so, especially in light of human activity and climate change. Because the introduction and spread of these species, their close relatives, and hybrids into the region is known to have occurred almost entirely from areas in North America outside of the Basin, our effort will include non-indigenous specimens collected from throughout North America. Digitized specimens of Great Lakes non-indigenous species and their congeners will allow for more accurate identification of invasive species and hybrids from their non-invasive relatives by a wider audience of end users. The metadata derived from digitized specimens of Great Lakes non-indigenous species and their congeners will help biologists to track, monitor, and predict the spread of invasive species through space and time, especially in the face of a more rapidly changing climate in the upper Midwest. All together consortium members will digitize >2 million individual specimens from >860,000 sheets/lots of non-indigenous species and their congeneric taxa. Data and metadata are uploaded to the Great Lakes Invasives Network, a Symbiota portal (GreatLakesInvasvies.org), and ingested by the National Resource for Advancing Digitization of Biodiversity Collections (ADBC) (iDigBio.org) national resource. Several initiatives are already in place to alert citizens to the dangers of spreading aquatic invasive species among our nation's waterways, but this project is developing complementary scientific and educational tools for scientists, students, wildlife officers, teachers, and the public who have had little access to images or data derived directly from preserved specimens of invasive species collected over the past three centuries.


Water ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 3459
Author(s):  
Jie Wei ◽  
Zhulan Nie ◽  
Fenfen Ji ◽  
Longhui Qiu ◽  
Jianzhong Shen

The Kizil reservoir in the Tarim River basin is an important habitat for the native Schizothoracinae fish (including Aspiorhynchus laticeps, Schizothorax biddulphi, Schizothorax eurystomus, Schizothorax intermedius and Schizothorax barbatus). Unfortunately, these species are threatened by many exotic fish, such as Ctenopharyngodon idellus, Silurus asotus. As an isolated habitat, the Kizil reservoir is an ideal area for studying biological invasions. However, the impact of invasive species on indigenous species in this reservoir remains unknown. In this study, the niche width and niche overlap between invasive and indigenous species in Kizil reservoir were studied based on stable isotope analysis. The results showed that niche width of two invasive species, S. asotus and C. idellus, was larger than that of native fish species, which confirmed the hypotheses that successful invaders have larger niche width. The niche overlap analysis showed that the two invasive species had high niche overlap with native fish species, which meant that there might be intensive interspecific competitions between them. The invasion of non-native species could be the main reason for the decrease of native species in the Kizil reservoir.


2021 ◽  
Vol 8 ◽  
Author(s):  
Ricardo Cruz de Carvalho ◽  
Eduardo Feijão ◽  
Irina Duarte ◽  
Vanessa Pinto ◽  
Marisa Silva ◽  
...  

The invasion of natural communities by non-indigenous species represents one of the most serious threats to biodiversity. Understanding the ecophysiology of invasive species can provide insights into potential physiological handicaps relative to native species. By doing so, we can leverage the development of ecoengineering solutions for the removal of non-indigenous species, preferably using non-chemical methods. Spartina patens is a known invasive species of cordgrass aggressively proliferating in Mediterranean salt marshes, producing impenetrable monospecific stands. As its occurrence is delimited by the upper high tide water level, we hypothesized that S. patens is intolerant to waterlogging. Therefore, we developed a field experiment where strands of S. patens were kept waterlogged over the entire tidal cycle for 30 days. At the end of the experimental period, plants in the trial plots exhibited severe stress symptoms at different physiological levels compared with control plots (no intervention). At the photobiological level, intervened plants exhibited lower efficiency in producing chemical energy from light, whilst at the biochemical level waterlogging impaired the antioxidant system and increased lipid peroxidation products. Furthermore, the application of chlorophyll a pulse amplitude modulated (PAM) fluorometry, a non-invasive technique, allowed us to evaluate the effectiveness of the implemented measures, being the tool that provided the best separation between the control and intervened population. Considering the physiological traits observed here, ecoengineering solutions based on increased waterlogging of S. patens stands, can be a low-cost and efficient measure to reduce the spreading and growth of this invasive species in the Mediterranean and other salt marshes worldwide with little disturbance.


Diversity ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 176
Author(s):  
Julissa J. Sánchez-Velásquez ◽  
Lorenzo E. Reyes-Flores ◽  
Carmen Yzásiga-Barrera ◽  
Eliana Zelada-Mázmela

Early detection of non-indigenous species is crucial to reduce, mitigate, and manage their impacts on the ecosystems into which they were introduced. However, assessment frameworks for identifying introduced species on the Pacific Coast of South America are scarce and even non-existent for certain countries. In order to identify species’ boundaries and to determine the presence of non-native species, through morphological examinations and the analysis of the plastid ribulose-1,5-bisphosphate carboxylase/oxygenase large subunit (rbcL-5P) gene, we investigated the phylogenetic relationships among species of the class Florideophyceae from the coast of Ancash, Peru. The rbcL-5P dataset revealed 10 Florideophyceae species distributed in the following four orders: Gigartinales, Ceramiales, Halymeniales, and Corallinales, among which the Asian species, Melanothamnus japonicus (Harvey) Díaz-Tapia & Maggs was identified. M. japonicus showed a pairwise divergence of 0% with sequences of M. japonicus from South Korea, the USA, and Italy, the latter two being countries where M. japonicus has been reported as introduced species. Our data indicate a recent introduction event of M. japonicus in Peru, and consequently, the extension of its distribution into South America. These findings could help to adopt management strategies for reducing the spread and impact of M. japonicus on the Pacific Coast of South America.


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