scholarly journals Ecological impacts of invasive carp in Australian dryland rivers

2019 ◽  
Vol 29 (11) ◽  
pp. 1870-1889 ◽  
Author(s):  
Jonathan C. Marshall ◽  
Joanna J. Blessing ◽  
Sara E. Clifford ◽  
Kate M. Hodges ◽  
Peter M. Negus ◽  
...  
Keyword(s):  
Ecological Impacts ◽  
Dryland Rivers

High predatory efficiency and abundance drive expected ecological impacts of a marine invasive fish

2020 ◽  
Vol 637 ◽  
pp. 195-208 ◽  
Author(s):  
EM DeRoy ◽  
R Scott ◽  
NE Hussey ◽  
HJ MacIsaac
Keyword(s):  
Invasive Species ◽  
Native Species ◽  
Ecological Impact ◽  
Marine Species ◽  
Ecological Impacts ◽  
Negative Effects ◽  
Marine Predator ◽  
Eastern Gulf Of Mexico ◽  
Red Grouper ◽  
Per Capita

The ecological impacts of invasive species are highly variable and mediated by many factors, including both habitat and population abundance. Lionfish Pterois volitans are an invasive marine species which have high reported detrimental effects on prey populations, but whose effects relative to native predators are currently unknown for the recently colonized eastern Gulf of Mexico. We used functional response (FR) methodology to assess the ecological impact of lionfish relative to 2 functionally similar native species (red grouper Epinephelus morio and graysby grouper Cephalopholis cruentata) foraging in a heterogeneous environment. We then combined the per capita impact of each species with their field abundance to obtain a Relative Impact Potential (RIP). RIP assesses the broader ecological impact of invasive relative to native predators, the magnitude of which predicts community-level negative effects of invasive species. Lionfish FR and overall consumption rate was intermediate to that of red grouper (higher) and graysby grouper (lower). However, lionfish had the highest capture efficiency of all species, which was invariant of habitat. Much higher field abundance of lionfish resulted in high RIPs relative to both grouper species, demonstrating that the ecological impact of lionfish in this region will be driven mainly by high abundance and high predator efficiency rather than per capita effect. Our comparative study is the first empirical assessment of lionfish per capita impact and RIP in this region and is one of few such studies to quantify the FR of a marine predator.

scholarly journals Future large hydropower dams impact global freshwater megafauna

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Christiane Zarfl ◽  
Jürgen Berlekamp ◽  
Fengzhi He ◽  
Sonja C. Jähnig ◽  
William Darwall ◽  
...  
Keyword(s):  
Spatial Scales ◽  
Point Of View ◽  
Ecological Impacts ◽  
Climate Mitigation ◽  
Threat Status ◽  
Hydropower Dams ◽  
Balkan Region ◽  
America South ◽  
Freshwater Management ◽  
Major Attention

AbstractDam construction comes with severe social, economic and ecological impacts. From an ecological point of view, habitat types are altered and biodiversity is lost. Thus, to identify areas that deserve major attention for conservation, existing and planned locations for (hydropower) dams were overlapped, at global extent, with the contemporary distribution of freshwater megafauna species with consideration of their respective threat status. Hydropower development will disproportionately impact areas of high freshwater megafauna richness in South America, South and East Asia, and the Balkan region. Sub-catchments with a high share of threatened species are considered to be most vulnerable; these are located in Central America, Southeast Asia and in the regions of the Black and Caspian Sea. Based on this approach, planned dam locations are classified according to their potential impact on freshwater megafauna species at different spatial scales, attention to potential conflicts between climate mitigation and biodiversity conservation are highlighted, and priorities for freshwater management are recommended.

scholarly journals Quantifying the Response of Grass Carp Larvae to Acoustic Stimuli Using Particle-Tracking Velocimetry

Water ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 603
Author(s):  
Hojung You ◽  
Rafael O. Tinoco
Keyword(s):  
Particle Tracking ◽  
Grass Carp ◽  
Particle Tracking Velocimetry ◽  
Quantitative Imaging ◽  
Functional Relation ◽  
Acoustic Signals ◽  
Ecological Impacts ◽  
Ctenopharyngodon Idella ◽  
Response Ratio ◽  
Larval Behavior

Acoustic deterrents are recognized as a promising method to prevent the spread of invasive grass carp, Ctenopharyngodon idella (Valenciennes, 1844) and the negative ecological impacts caused by them. As the efficacy of sound barriers depends on the hearing capabilities of carp, it is important to identify whether carps can recognize acoustic signals and alter their swimming behavior. Our study focuses on quantifying the response of grass carp larvae when exposed to out-of-water acoustic signals within the range of 100–1000 Hz, by capturing their movement using particle-tracking velocimetry (PTV), a quantitative imaging tool often used for hydrodynamic studies. The number of responsive larvae is counted to compute response ratio at each frequency, to quantify the influence of sound on larval behavior. While the highest response occurred at 700 Hz, we did not observe any clear functional relation between frequency of sound and response ratio. Overall, 20–30% of larvae were consistently reacting to sound stimuli regardless of the frequency. In this study, we emphasize that larval behaviors when exposed to acoustic signals vary by individual, and thus a sufficient number of larvae should be surveyed at the same time under identical conditions, to better quantify their sensitivity to sound rather than repeating the experiment with individual specimens. Since bulk quantification, such as mean or quantile velocities of multiple specimens, can misrepresent larval behavior, our study finds that including the response ratio can more effectively reflect the larval response.

Meta-analysis on the ecological impacts of widely spread non-indigenous species in the Baltic Sea

2021 ◽  
pp. 147375
Author(s):  
Henn Ojaveer ◽  
Jonne Kotta ◽  
Okko Outinen ◽  
Heli Einberg ◽  
Anastasija Zaiko ◽  
...  
Keyword(s):  
Baltic Sea ◽  
Meta Analysis ◽  
Ecological Impacts ◽  
Indigenous Species ◽  
The Baltic Sea ◽  
The Baltic ◽  
Non Indigenous Species

scholarly journals Shift in polar benthic community structure in a fast retreating glacial area of Marian Cove, West Antarctica

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hanna Bae ◽  
In-Young Ahn ◽  
Jinsoon Park ◽  
Sung Joon Song ◽  
Junsung Noh ◽  
...  
Keyword(s):  
Community Structure ◽  
Benthic Community ◽  
Adaptive Strategy ◽  
Ecological Impacts ◽  
Glacier Retreat ◽  
Benthic Diatoms ◽  
Subtidal Zone ◽  
Benthic Community Structure ◽  
Community Shift ◽  
Global Issue

AbstractGlacier retreat is a major long-standing global issue; however, the ecological impacts of such retreats on marine organisms remain unanswered. Here, we examined changes to the polar benthic community structure of “diatoms” under current global warming in a recently retreated glacial area of Marian Cove, Antarctica. The environments and spatiotemporal assemblages of benthic diatoms surveyed in 2018–2019 significantly varied between the intertidal (tidal height of 2.5 m) and subtidal zone (10 and 30 m). A distinct floral distribution along the cove (~ 4.5 km) was characterized by the adaptive strategy of species present, with chain-forming species predominating near the glacier. The predominant chain-forming diatoms, such as Fragilaria striatula and Paralia sp., are widely distributed in the innermost cove over years, indicating sensitive responses of benthic species to the fast-evolving polar environment. The site-specific and substrate-dependent distributions of certain indicator species (e.g., F. striatula, Navicula glaciei, Cocconeis cf. pinnata) generally reflected such shifts in the benthic community. Our review revealed that the inner glacier region reflected trophic association, featured with higher diversity, abundance, and biomass of benthic diatoms and macrofauna. Overall, the polar benthic community shift observed along the cove generally represented changing environmental conditions, (in)directly linked to ice-melting due to the recent glacier retreat.

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