The genetic impact of introduced fishes on native species

1990 ◽  
Vol 68 (5) ◽  
pp. 1053-1057 ◽  
Author(s):  
Moira M. Ferguson

The introduction of nonnative fishes or "exotics" and transplants of fishes outside their geographic range but within the same country is a contentious issue. The effects of these introductions on native fish faunas are well documented and have resulted in legislation controlling future introductions of alien species and management policies based largely on living with past mistakes. However, fish introductions also occur at two more subtle levels: transfers within the range of the species, and introduction of foreign DNA to produce "transgenics." The rationale for transfers is largely typological in that "a fish is a fish," at least as far as any given species might be concerned. Transfers disregard the concept that species are divided into genetically distinct units or "stocks" adapted to their particular environment and that introduction of nonlocal conspecifics can disrupt the genetics and adaptation of local populations. This paper raises some of the major issues and the need to synthesize the concepts, documented cases, and effects.

2011 ◽  
Vol 9 (4) ◽  
pp. 915-919 ◽  
Author(s):  
Valter Monteiro de Azevedo-Santos ◽  
Odila Rigolin-Sá ◽  
Fernando Mayer Pelicice

Cage aquaculture has been developed in many countries, including Brazil. This form of production, although economically productive, may cause several impacts to the environment. Considering the historical relationship between aquaculture and species introduction, our study investigated the potential of cage aquaculture in spreading non-native species into hydroelectric reservoirs. We interviewed 19 fish farmers in Furnas Reservoir, Grande River basin. All producers have grown exclusively Nile tilapia (Oreochromis niloticus), an African fish, and all producers reported the occurrence of fish escapes. Releases were mainly accidental, but highly frequent during some management procedures, such as length classification, fish capture and juvenile stocking. Escapes were also reported due to cage damage and deliberate releases. These results indicate that, in cage aquaculture facilities, fish are frequently released to the external environment. When raising non-native species (e.g. Furnas Reservoir), these facilities constitute an important vector for fish introductions.


Hydrobiologia ◽  
2020 ◽  
Vol 847 (14) ◽  
pp. 3055-3065
Author(s):  
Niall G. Clancy ◽  
Samuel L. Bourret

Abstract The spread of non-native fish species is a common problem in lakes and streams worldwide. Species that establish viable populations in a new environment can seriously deplete populations of native species and desired sportfishes. In some instances, extirpation of a native species has occurred. In western North America, the most common avenue by which non-native species invade new waterbodies is illegal stocking by anglers, aquaculturists, and others. Thus, preventing further illegal fish introductions is of the utmost importance for native aquatic species. Using data collected by state agency personnel from 1953 to 2015, we examined multiple social and physical variables to determine the factors that best explain which lakes in northwestern Montana had past illegal fish introductions. An equation using elevation, surrounding population, and fishing pressure was found to best fit the data. This equation was then used to calculate an index of the vulnerability of lakes within the region to future illegal fish introductions. The techniques used in this study have broad applicability that can be used in many regions with illegal fish introductions, and ultimately help to alleviate the problem.


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.


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.


2016 ◽  
Vol 1 (1) ◽  
pp. 21 ◽  
Author(s):  
Tri Trijoko ◽  
Donan Satria Yudha ◽  
Rury Eprilurahman ◽  
Setiawan Silva Pambudi

The diversity of freshwater fishes which inhabit in the river of Daerah Istimewa Yogyakarta is not yet well documented. Complete documentation is needed as starting point and continuous research on the fish diversity in DIY. Boyong-Code River flows across the DIY, and it upstream is located on the hillside of Merapi volcano. The Code River upstream is called Boyong River. The research was aimed to acquire data about the diversity of fish fauna along the Boyong-Code River in the DIY. Further, the research purpose is to know which species are rare, potential for aquaculture, and introductive. Samples are taken along the Boyong-Code River starting from upstream to downstream. Samples were collected using Purposive Random Sampling methods with fishnets. Sampling area generally divided into three location i.e., upstream, middle-stream and downstream. Species diversity of fish in the Boyong-Code River is consisted of 24 species, with 5 introductive species. There are eleven native fish species which are potential for cultivation (aquaculture), i.e.: Barbodes binotatus, Mystacoleucus obtusirostris, Rasbora lateristriata, Rasbora argyrotaenia, Barbonymus balleroides, Osteochilus vittatus, Hampala macrolepidota, Anabas testudineus, Channa striata, Clarias leiacanthus and Clarias batrachus. The Boyong-Code River is a decent habitat for fishes. Many introduced fishes starting to invade the Boyong-Code River intentionally or unintentionally by human


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.


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.


1991 ◽  
Vol 48 (S1) ◽  
pp. 167-170 ◽  
Author(s):  
Paul J. Wingate

A survey of the poiicy of 50 U.S. states on transplanted fish introductions and stocking fish of different genetic strains indicates that all 39 responding states control exotic introductions. While 67% of the responding states restrict in-state movement of fish species, more attention is being given to restricting in-state strain movement. More needs to be done. Native species are stocked on top of reproducing populations and moved among watersheds; exotic species are introduced. In some cases, these stockings have appeared to benefit all interested parties, while in other circumstances exotics have totally disrupted ecosystems and become pests. These introductions and stockings are a combination of the fish being available, misunderstanding by managers of possible effects, and strong political pressure to satisfy anglers in more and more waters. Many times, little attention is given to the effect of these introductions on the native biota and fauna as it is perceived that stocking fish is a good thing. It is not until problems develop or anglers want another species added that the wisdom or success of these stockings is questioned. Minnesota's policy is that fish are not moved between watersheds until genetic similarities of the various species in the different watersheds are demonstrated.


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