scholarly journals An ensonified bubble curtain blocks 4 species of invasive carp in a laboratory flume but also deters other fish, while sound alone is less effective overall and does not target carp

Author(s):  
Jane Rose Feely ◽  
Peter Sorensen

Abstract Four species of invasive carp from Asia are advancing up the Mississippi River through its locks and dams and threatening to damage to its ecosystems. It has been hypothesized that sensory stimuli could be projected into locks to block the movement of these carp. Sound has garnered attention because carp are hearing specialists, so they might be targetable. A recent study demonstrated that when a broadband cyclic sound was projected into an air curtain to create an ensonified bubble curtain (EBC), it was especially effective at blocking bighead and common carp and less effective at blocking a native species that lacked hearing specializations, while sound alone was generally less effective. However, whether an EBC might be similarly and uniquely effective at blocking all species of carp, and what its effects might be on other fishes in general, has not yet been addressed. To answer these questions, this study examined the responses of 10 species of fishes including 4 carps, 2 native hearing specialists, and 4 native non-specialists in a darkened laboratory flume while either a cyclic sound was played on its own or projected into an air curtain. The EBC blocked all 4 carps 9297% of the time without habituation, but 5 native fish were also partially blocked. In contrast, sound alone only blocked 2 carps and affected the other fishes in ways not related to their hearing abilities. An EBC appears well suited to blocking carp invasions, especially if native fish movement is a secondary concern.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Łukasz Głowacki ◽  
Andrzej Kruk ◽  
Tadeusz Penczak

AbstractThe knowledge of biotic and abiotic drivers that put non-native invasive fishes at a disadvantage to native ones is necessary for suppressing invasions, but the knowledge is scarce, particularly when abiotic changes are fast. In this study, we increased this knowledge by an analysis of the biomass of most harmful Prussian carp Carassius gibelio in a river reviving from biological degradation. The species' invasion followed by the invasion's reversal occurred over only two decades and were documented by frequent monitoring of fish biomass and water quality. An initial moderate improvement in water quality was an environmental filter that enabled Prussian carp’s invasion but prevented the expansion of other species. A later substantial improvement stimulated native species’ colonization of the river, and made one rheophil, ide Leuciscus idus, a significant Prussian carp’s replacer. The redundancy analysis (RDA) of the dependence of changes in the biomass of fish species on water quality factors indicated that Prussian carp and ide responded in a significantly opposite way to changes in water quality in the river over the study period. However, the dependence of Prussian carp biomass on ide biomass, as indicated by regression analysis and analysis of species traits, suggests that the ecomorphological similarity of both species might have produced interference competition that contributed to Prussian carp’s decline.


2019 ◽  
Vol 1 (4) ◽  
pp. 283-291
Author(s):  
Kevin J. Walker ◽  
Simon Leach ◽  
Chris Preston ◽  
Thomas Humphrey ◽  
Trevor James ◽  
...  

Information on the origin (status) and regeneration of plant species improves our understanding of native distributions and the establishment of non-native species. However, current categories used to record status in Britain and Ireland, whilst conceptually informative, rely on a knowledge of persistence that is impossible to assess objectively during a single (one-off) recording visit. We propose five alternative categories that focus on origin (how a species arrived at a site) rather than persistence. The first two categories apply to nationally native taxa: (1) populations that are unequivocally native and (2) those that are likely to have been introduced and/or are spreading for reasons that are obscure. The other three categories cover the occurrences of any taxon, native or non-native, that is known or suspected to have been introduced to a site: (3) introductions with unknown/obscure origins; (4) deliberate introductions; and (5) accidental introductions. For the introduced categories 3-5 we recommend that botanists also record signs of regeneration, i.e. seedlings or widely scattered patches, as a more objective measure whether a species is likely to be self-sustaining in a given locality.


Author(s):  
Tatia Kuljanishvili ◽  
Levan Mumladze ◽  
Bella Japoshvili ◽  
Namig Mustafayev ◽  
Shaig Ibrahimov ◽  
...  

The South Caucasus (SC) region is recognized for its high biological diversity and various endemic animal taxa. The area has experienced many fish introductions over the years, but the overall information about non-native fishes in the three SC countries, Armenia, Azerbaijan, and Georgia did not exist. Although these three countries belong to the Kura River drainage, Caspian Sea basin (only the western half of Georgia drains into the Black Sea), the legislative framework for each country regarding introduction of non-native fish species and their treatment is different and poorly developed. The goal of the present study was to make an initial inventory of non-native fish species in the three SC countries, and summarize the existing knowledge as a basis for future risk assessment models and formulation of regional management policies. Here, we present a unified list of 27 non-native species recorded in the wild in Armenia, Azerbaijan, and Georgia. Among these 27 species, eight were translocated from the Black Sea basin to the Caspian Sea basin. Out of these 27 non-native fishes, 15 species have become established (three of them being considered invasive) and six fish species could not survive in the wild.


2018 ◽  
Vol 11 (1) ◽  
pp. 69-77
Author(s):  
Fabrizio Perroni ◽  
Eric Mol ◽  
Anthony Walker ◽  
Calogero Alaimo ◽  
Laura Guidetti ◽  
...  

Background: In order to stay safe, and to successfully complete their work, firefighters have to constantly assess and process large numbers of sensory stimuli and adapt to the inherent risks present in the working environment. Objective: The purposes of the present preliminary study were to analyse the speed of Reaction Time responses (RT) of Italian Firefighters and to compare their cognitive responses with non-firefighting subjects. Methods: Anthropometric (weight, height and BMI) and RT (time-to-completion –TTC-, mean of reaction time –MRT-, and errors made -E-) evaluations were administered at 16 volunteers (Age: 40.3 ± 6.7 yrs; BMI: 23.8 ± 2.3 kg/m2) divided in Firefighters (FG) and Control (CG) groups. RT test consisted of 3 trials (T1 = 1s of stimulus duration and 1s interval between stimulus and the other; T2 = 0.5s of stimulus duration and 1s interval between stimulus and the other; T3 = 0.5s of stimulus duration and 0.5s interval between stimulus and the other). Mann Whitney U test between groups was applied to asses differences (p ≤ 0.05) in TTC, MRT, and E while Friedmann test and Dunn-Sidak post hoc were used to evaluate significant differences in the 3 trials in each variable of each group. Results: No significant differences based on anthropometric parameters were observed between groups. Despite no significant differences emerged for TTC and MRT between groups, we observed significant differences in E between groups (CG = 4; FG =12) and in the 3rd condition in each variable of each group. Conclusion: Workout programs that integrate reaction time training with job performance should be created to increase job performance.


2020 ◽  
Vol 71 (11) ◽  
pp. 1464
Author(s):  
John D. Koehn ◽  
Stephen R. Balcombe ◽  
Lee J. Baumgartner ◽  
Christopher M. Bice ◽  
Kate Burndred ◽  
...  

The Murray–Darling Basin (MDB) is Australia’s food bowl, contributing 40% of agricultural production and supporting a population of over 4 million people. Historically, the MDB supported a unique native fish community with significant cultural, subsistence, recreational, commercial and ecological values. Approximately one-quarter of the MDB’s native species are endemic. Changes to river flows and habitats have led to a >90% decline in native fish populations over the past 150 years, with almost half the species now of conservation concern. Commercial fisheries have collapsed, and important traditional cultural practices of First Nations People have been weakened. The past 20 years have seen significant advances in the scientific understanding of native fish ecology, the effects of human-related activities and the recovery measures needed. The science is well established, and some robust restoration-enabling policies have been initiated to underpin actions. What is now required is the political vision and commitment to support investment to drive long-term recovery. We present a summary of 30 priority activities urgently needed to restore MDB native fishes.


2021 ◽  
Vol 49 (4) ◽  
pp. 649-653
Author(s):  
David Julián Palma-Cancino ◽  
Mao Ernesto Rafael Basto-Rosales ◽  
Carlos Alfonso Álvarez-González ◽  
Rafael Martínez-García ◽  
Daniel Badillo-Zapata ◽  
...  

The development of native fish aquaculture represents an important alternative to mitigate ecological displacement generated by exotic fish. The introduction of native fish in polyculture systems with high commercial value fishes has provided a useful strategy for sustainable aquaculture development. The present study aims to provide information on tilapia, as an exotic species, and Dormitator latifrons, as a native species, in a duo culture not programmed as such. Using juveniles of Pacific fat sleeper D. latifrons leftovers from another experiment, we decide to analyze and report the biological feasibility of a duoculture system with this species and Nile tilapia (Oreochromis niloticus). Two hundred fifty organisms of each species were placed for 90 days in a concrete tank with a capacity of 50 m3 to evaluate the compatibility of these species. The biological variables measured were growth, survival, feed conversion rate, and protein efficiency. The findings suggest a good interaction between species, with adequate growths and a survival rate of 98%. No antagonistic behavior was observed during confinement, suggesting the duoculture of these species may represent a good alternative for tropical sustainable aquaculture.


The Holocene ◽  
2018 ◽  
Vol 28 (11) ◽  
pp. 1771-1780 ◽  
Author(s):  
Edson P Silva ◽  
Rosa CCL Souza ◽  
Tania A Lima ◽  
Flávio C Fernandes ◽  
Kita D Macario ◽  
...  

Interactions between invader species and the local biota may lead to disequilibria in regional ecosystems. For such reason, the cultivation of nonnative species may be prohibited in specific regions, as a means of protecting native species. On the other hand, the question of whether a species is a bioinvader or not may not be straightforward. This is the case of the mollusc Perna perna, presently naturalized and widely distributed along Brazilian coast, from the Bay of Vitória, in the state of Espírito Santo (ES), to the state of Rio Grande do Sul (RS). Following previous works that explored the hypothesis that P. perna invaded the coast of Brazil at the colonial period, attached to slave ships, we discuss zooarchaeological data, radiocarbon dating, and molecular genetics analyses. Out of the 578 archeological shellmounds investigated, 542 (93.8%) had no records of P. perna. From the radiocarbon dating results, it is possible to infer that the presence of the two P. perna specimens from the Saquarema shellmound, in Rio de Janeiro, as well as the other shells from the top layer, is likely related to a recent occupation of the site in the colonial period, with a great probability of being from the XVII or XVIII centuries. Data on genetic population structure of P. perna along the Brazilian coast showed higher genetic identities between the African and the Brazilian populations than among the Brazilian populations, while haplotypic diversity shows a pattern which relates to trade routes of slaves (XVII and XVIII centuries) between Africa and Brazil. These data reinforce the argument that the appearance of P. perna along the Brazilian coast is due to invasion during historical time.


Author(s):  
András Specziár ◽  
Tibor Erős

A fish-based index is proposed to indicate the ecological status of Lake Balaton, Hungary in accordance with the standard of the European Water Framework Directive (WFD). The Balaton fish index (BFI) synthetises information of 13 lake-specific fish metrics including gillnetting and electric fishing data of species richness of native assemblages, relative abundance, biomass and age structure of native key species, representation of non-native species and general health status. The main anthropogenic pressures considered were the degradation of littoral habitats, invasion of non-native fish species, eutrophication and fishing/angling including stocking. Ecological quality ratio (EQR) is assessed by relating actual fish assemblage metrics to the supposed undisturbed reference status of Lake Balaton reconstructed by expert judgement based on recent and historic information on the fish fauna and its changes. Values of BFI were consistent and indicated good ecological status of Lake Balaton in the period of 2005–2018. This study provides an example on how an EQR assessment methodology might be established in unique habitats with no possibilities for statistical evaluation of pressure-respond relationships and exact determination of the reference status.


1980 ◽  
Vol 31 (1) ◽  
pp. 61 ◽  
Author(s):  
PD Jackson ◽  
WD Williams

Eight species of native fish and two of introduced fish were found during studies of the distribution of fishes in streams in three areas of southern Victoria; namely in the upper part of the catchment of the Yarra River, in the Otway Ranges, and on Wilsons Promontory. S. trutta does not occur on Wilsons Promontory, but does occur in the other two areas. Results provide circumstantial evidence that S. trutta has deleteriously affected the occurrence of Galaxias olidus and possibly G. brevipinnis. Some native fishes appear able to coexist with S. trutta.


2012 ◽  
Vol 18 (2) ◽  
pp. 77 ◽  
Author(s):  
Heather Parks ◽  
Kyle Clifton ◽  
Lauren Best ◽  
Bridget Johnson

PEST-PROOF (exclusion) fences are designed to prevent non-native, predatory and pest species from repopulating an area set aside to protect vulnerable native plant and animal species. Pest-proof fencing provides security from invasive species, but can isolate the native species enclosed within. On one hand, some rare native species exist on the mainland due to the pest-free status achieved through the use of exclusion fences. On the other hand, these reintroduced populations are now isolated a situation where they would not be found naturally (Jamieson et al. 2006). Exclusion fences must be constantly maintained or the sanctuary risks reinvasion. An important question for conservation biologists and managers to answer is therefore — when is exclusion fencing the best option for protecting native species from introduced pests? We have drawn our examples from New Zealand and Australia where progress has been made with regard to the design and utilization of exclusion fences.


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