scholarly journals Ichthyological Differentiation and Homogenization in the Pánuco Basin, Mexico

Diversity ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 187 ◽  
Author(s):  
Norma Martínez-Lendech ◽  
Ana P. Martínez-Falcón ◽  
Juan Jacobo Schmitter-Soto ◽  
Humberto Mejía-Mojica ◽  
Valentino Sorani-Dalbón ◽  
...  
Keyword(s):  
Species Composition ◽  
Native Species ◽  
Ecosystem Change ◽  
Species Introductions ◽  
Fish Collection ◽  
Species Groups ◽  
Conservation Concern ◽  
Key Aspects ◽  
Independent Species ◽  
Over Time

Species introductions and extirpations are key aspects of aquatic ecosystem change that need to be examined at large geographic and temporal scales. The Pánuco Basin (Eastern Mexico) has high ichthyological diversity and ecological heterogeneity. However, freshwater fish (FWF) introductions and extirpations since the mid-1900s have modified species range and distribution. We examine changes in FWF species composition in and among four sub-basins of the Pánuco by comparing fish collection records pre-1980 to 2018. Currently, the FWF of the Pánuco includes 95 species. Fishes in the Poeciliidae, Cyprinidae, and Cichlidae, respectively, comprised most records over time. Significant differences in species composition were found between the first (pre-1980) and last (2011–2018) study periods, but not for periods in-between. Eight independent species groups were key for explaining changes in Pánuco river ichthyofauna; one group was dominated by invasive species, and saw increases in the number of records across study periods (faunal homogenization). Another group was formed by species with conservation concern with a declining number of records over time. Thirteen (2 native and 11 non-native) species were responsible for temporal turnover. These results strongly suggest high rates of differentiation over time (via native species loss) following widespread non-native species introductions.

Black Bass Diversity: Multidisciplinary Science for Conservation

2015 ◽  
Keyword(s):  
South Carolina ◽  
Native Species ◽  
Smallmouth Bass ◽  
Hybrid Origin ◽  
Nonnative Species ◽  
Savannah River ◽  
Conservation Actions ◽  
Precipitous Decline ◽  
Conservation Concern ◽  
Over Time

<em>Abstract</em>.—Bartram’s Bass (an as yet unnamed species similar to Redeye Bass <em>Micropterus coosae</em>) is endemic to the Savannah drainage of South Carolina and Georgia. Hybridization between this native species and introduced Alabama Bass <em>M. henshalli </em>is widespread in the upper portions of the drainage. Recent studies have documented a precipitous decline in genetically pure Bartram’s Bass in Savannah drainage reservoirs and a corresponding increase in fish of hybrid origin. We surveyed tributary populations associated with these reservoirs and with the Savannah River main stem in 2004 and 2010. Results indicate an increased occurrence of hybrids in Bartram’s Bass native stream habitats over time. We also document the new occurrence of a second nonnative species, Smallmouth Bass <em>M. dolomieu</em>. Both Smallmouth Bass and their hybrids with Bartram’s Bass were collected from shoals in the Savannah River near the lower extent of the Bartram’s Bass range. Bartram’s Bass is a species of highest conservation concern in South Carolina, due to its limited native range and threats associated with hybridization. Conservation actions directed at this species, and its native stream habitats, will need to consider the establishment of nonnative species in the drainage and their potential to impact tributary populations over time.

scholarly journals Priority Treatment Leaves Grassland Restoration Vulnerable to Invasion

Diversity ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 71 ◽  
Author(s):  
Katharine L. Stuble ◽  
Truman P. Young
Keyword(s):  
Native Species ◽  
Priority Effects ◽  
Native Grasses ◽  
Target Species ◽  
California Grasslands ◽  
Early Arrival ◽  
Regional Species Pool ◽  
Conservation Concern ◽  
Indirect Impacts ◽  
One Year

Priority effects can be used to promote target species during restoration. Early planting can provide an advantage over later-arriving species, increasing abundance of these early-arrivers in restored communities. However, we have limited knowledge of the indirect impacts of priority effects in restoration. In particular, we do not understand how priority effects impact non-target species. Of particular conservation concern is how these priority effects influence establishment by non-native species. We use a field-based mesocosm experiment to explore the impacts of priority effects on both target and non-target species in California grasslands. Specifically, we seeded native grasses and forbs, manipulating order of arrival by planting them at the same time, planting forbs one year before grasses, planting grasses one year before forbs, or planting each functional group alone. While our study plots were tilled and weeded for the first year, the regional species pool was heavily invaded. We found that, while early-arrival of native grasses did not promote establishment of non-native species, giving priority to native forbs ultimately left our restoration mesocosms vulnerable to invasion by non-native species. This suggests that, in some cases, establishment of non-native species may be an unintended consequence of using priority treatments as a restoration tool.

scholarly journals Dispersão de Espécie Exótica no Parque Nacional da Lagoa do Peixe e Seu Entorno (Dispersion of Exotic Vegetation Into and Around the Lagoa do Peixe National Park)

2011 ◽  
Vol 4 (1) ◽  
pp. 33 ◽  
Author(s):  
Luana Portz ◽  
Rogério Portantiollo Manzolli ◽  
Dejanira Luderitz Saldanha ◽  
Iran Carlos Stalliviere Correa
Keyword(s):  
Native Species ◽  
National Park ◽  
Rio Grande ◽  
Multispectral Images ◽  
Rio Grande Do Sul ◽  
Field Verification ◽  
Exotic Vegetation ◽  
Manual Classification ◽  
Natural Dispersal ◽  
Over Time

O Parque Nacional da Lagoa do Peixe está localizado no litoral sul do estado do Rio Grande do Sul. Dentre os conflitos existentes dentro da área do parque e no seu entorno, o aumento e a dispersão da vegetação exótica, vem gerando inúmeras discussões. Neste contexto o objetivo do presente trabalho foi identificar a distribuição espacial, ao longo do tempo, das áreas de plantações de Pinus sp. Para tanto foram utilizadas imagens multiespectrais de sensoriamento remoto (TM-Landsat 5), com datas entre 1986 e 2009, sendo realizada a classificação manual por meio da vetorização, verificação de campo e análise quantitativa e qualitativa dos resultados obtidos. O problema principal da dispersão natural de Pinus sp. é encontrado na margem da lagoa principal, margeada por banhados e por pinus, cuja dispersão espontânea está competindo com o crescimento da vegetação natural e alterando o cenário típico da região. De 1986, data de criação do parque, até hoje a área de pinus, no entorno desta lagoa, cresceu de 61 para 252 ha. Este aumento da área de ocorrência de Pinus sp, em mais de 4 vezes, torna necessária a sua extração, a fim de preservar as espécies nativas da região, bem como a diversidade biológica a ela associada. A expansão da silvicultura é preocupante, pois assumiu uma grande proporção em área, não se encontrando ações que indiquem uma desaceleração deste processo. Além de diminuir o valor estético da paisagem natural esta invasão poderá comprometer o potencial turístico e principalmente de preservação ambiental ao qual o título de Parque Nacional exige.Palavras chaves: Pinus sp., Landsat, impactos. Dispersion of Exotic Vegetation Into and Around the Lagoa do Peixe National Park  ABSTRACTLagoa do Peixe National Park presents a great variety of fragile ecosystems. Among the conflicts present into and around the Park is the increase and dispersion of exotic vegetation, that is generating several discussions. In this context, the objective of this paper was identifying the spatial distribution, over time, of the Pinus sp. plantations in this area. For both researches, it was used multispectral images (Landsat), with dates between 1986 and 2009, and performed the manual classification, field verification and analysis of quantitative and qualitative results. The main problem related to the natural dispersal of Pinus sp. is found on the shore of the park’s main lagoon. This area is bordered by marshes and Pinus sp. whose spontaneous dispersion is competing with the natural vegetation and altering the typical scenery of this region. Since the creation of the park (1986) until today, the area of pinus, around the lagoon, has grown from 61 to 252 ha. This increase, more than four times, makes it necessary its extraction in order to preserve the native species and the biodiversity associated. The expansion of forestry in the Lagoa do Peixe National Park is worrisome because it has been taking a great extent of the area, and there are no actions that indicate a slowdown of this process.Keyword: Pinus sp., Landsat, impact.

scholarly journals Intrinsic Prey Preference and Selection of the Giant Gartersnake: A Threatened Predator in a Nonnative Prey-Dominated Community

2020 ◽  
Vol 11 (1) ◽  
pp. 164-173
Author(s):  
Julia S.M. Ersan ◽  
Brian J. Halstead ◽  
Erica L. Wildy ◽  
Michael L. Casazza ◽  
Glenn D. Wylie
Keyword(s):  
Exotic Species ◽  
Native Species ◽  
Prey Selection ◽  
Central Valley ◽  
Prey Preference ◽  
Live Prey ◽  
Species Of Conservation Concern ◽  
Conservation Concern ◽  
Behavioral Trials ◽  
Selection Of

Abstract The introduction of exotic species into an environment can introduce great change in the trophic dynamics of native species. This is of even greater concern if the native species is of conservation concern. The giant gartersnake, Thamnophis gigas, an endemic predator of the Central Valley of California and a species of conservation concern at the state and federal levels, has declined as a result of conversion of its once vast wetland habitat to agriculture. Another anthropogenic factor contributing to this snake's changing ecology is the introduction of nonnative prey into the species' habitats. These introductions have resulted in a prey community that is almost completely composed of exotic species and have potential for considerable effects. In order to assess prey preference and selection we performed three sets of behavioral trials on naïve neonates. We examined 1) neonate prey preference in response to olfactory cues of prepared prey extracts, 2) neonate consumption of different live prey items presented simultaneously; and 3) terrestrial feeding behavior and/or latency to successful attack. Results from the olfactory study suggest that native Sierran treefrogs, Pseudacris sierra, are preferred by neonates. Results from consumption trials suggest that neonates are more likely to select frog species than fish species. This is the first study that we are aware of that examines prey selection of this threatened species and serves to inform its conservation and management.

scholarly journals Decline in New Zealand's freshwater fish fauna: Effect of land use

2020 ◽  
Author(s):  
Michael Joy ◽  
KJ Foote ◽  
P McNie ◽  
M Piria
Keyword(s):  
New Zealand ◽  
Land Cover ◽  
Freshwater Fish ◽  
Native Species ◽  
Species Abundance ◽  
Fish Fauna ◽  
Fish Distribution ◽  
Individual Species ◽  
Freshwater Fish Fauna ◽  
Over Time

© 2019 CSIRO. The number of New Zealand's freshwater fish listed as threatened has increased since 1992 when the first New Zealand threat classification system list was compiled. In this study, temporal and land cover-related trends were analysed for data on freshwater fish distribution, comprising more than 20 000 records for the 47 years from January 1970 to January 2017 from the New Zealand Freshwater Fish Database. The analysis included individual species abundance and distribution trends, as well as an index of fish community integrity, namely the Index of Biotic Integrity (IBI). Of the 25 fish species that met the requirements for analysis to determine changes in the proportion of sites they occupied over time, 76% had negative trends (indicating declining occurrence). Of the 20 native species analysed for the proportion of sites occupied over time, 75% had negative trends; 65% of these were significant declines and more species were in decline at pasture sites than natural cover sites. The average IBI score also declined over the time period and, when analysed separately, the major land cover types revealed that the IBI declined at pasture catchment sites but not at sites with natural vegetation catchments.

scholarly journals What is needed to restore native fishes in Australia’s Murray–Darling Basin?

2020 ◽  
Vol 71 (11) ◽  
pp. 1464
Author(s):  
John D. Koehn ◽  
Stephen R. Balcombe ◽  
Lee J. Baumgartner ◽  
Christopher M. Bice ◽  
Kate Burndred ◽  
...  
Keyword(s):  
First Nations ◽  
Native Species ◽  
Cultural Practices ◽  
Native Fish ◽  
The Past ◽  
Murray Darling Basin ◽  
Native Fishes ◽  
Conservation Concern ◽  
First Nations People

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 &gt;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.

scholarly journals Artificial Perches for Birds in Deforested Areas Favour a Seed Rain Similar to Woodland Remnants

2021 ◽  
Author(s):  
Brenda Yamile Guidetti ◽  
Sebastian Dardanelli ◽  
Fátima María Lourdes Miño ◽  
Guillermo César Amico
Keyword(s):  
Species Richness ◽  
Species Composition ◽  
Ecological Restoration ◽  
Native Species ◽  
Seed Rain ◽  
Ecosystem Resilience ◽  
Behavioral Differences ◽  
Plant Seeds ◽  
Recovery Mechanisms ◽  
Trees And Shrubs

Abstract The lack of seeds represents one of the highest difficulties to overcome for the ecological restoration of areas that have been deforested. This study evaluates the effectiveness of artificial perches in increasing the abundance and species richness of bird-dispersed seeds and the similitude of seed rain composition (origin and habit of plant seeds), of deforested areas with and without artificial perches in relation to woodland remnants that serve as seeds source. The experiment took place in two sites of the Espinal ecoregion, Argentina. We found that in deforested areas, perches increased seed abundance and species richness in the seed rain in comparison with deforested areas without artificial perches. The species composition under artificial perches was similar to the seed rain dispersed in the woodland. However, a decrease in the richness of native species was significant in the deforested area, probably due to behavioral differences between opportunistic and obligate frugivorous. Seed of trees and shrubs species were well represented in the seed rain under artificial perches. Results from this study contribute to the understanding of nucleation and recovery mechanisms used by nature that reflect ecosystem resilience. We recommend using artificial perches in deforested areas with potential for recovery because it is an efficient technique to promote the entry of birds and increase seed rain, preserving features of the original environment. However, using artificial perches should be avoided in sites with potentially invasive non-native species.

Diversity of tropical macroalgae in the New Zealand marine aquarium trade

2021 ◽  
Author(s):  
◽  
Kirill Woodhouse
Keyword(s):  
New Zealand ◽  
Native Species ◽  
Temperature Tolerance ◽  
Sea Surface ◽  
Aquarium Trade ◽  
Species Introduction ◽  
Molecular Barcoding ◽  
Species Introductions ◽  
Foreign Land ◽  
Negative Impacts

<p>Exotic species often slip through international borders undetected. Many perish but for some species introduction to a foreign land or sea brings release from natural enemies and a chance to establish a population. Increased global trade has increased the frequency of species introductions through stowaways and lapses in biosecurity. Once an invader is established there is the opportunity for explosive population growth at the detriment of native species and humans. The marine aquarium trade is a significant vector of species introductions, including algal introductions. The most publicized introduction from aquaria was the release of the green alga Caulerpa taxifolia from the Oceanographic Museum in Monaco. C. taxifolia introduction had large negative impacts on the invaded ecosystem.  Molecular barcoding of tropical macroalgae entering the New Zealand aquarium trade was implemented using various molecular markers (cox1, cox3, rbcL tufA, LSU). Both NCBI Blast searches and maximum-likelihood phylogenies were used to identify the isolates. A total of 62 species of tropical macroalgae were identified from coral rocks imported into New Zealand, plus samples from reef hobbyists. Some species found are known as invasive elsewhere, for example, Caulerpa cylindracea, C. racemosa, C. sertularioides, Ulva ohnoi and Chaetomorpha vieillardii. All three major groups of algae were well represented in my findings with 26 species of red algae, 24 species of green algae and 12 species of brown algae. Temperature tolerance limits are the largest determinant in survival in algae, while salinity and pH are less significant. Temperature tolerance of tropical algae to the minimum Sea Surface Temperature in Auckland (14°C) and Wellington (11°C) was tested. My results show that one species Chaetomorpha vieillardii can survive at Auckland minimum winter sea surface temperatures. Our findings have important implications for New Zealand biosecurity, as not only are a large diversity of exotic macroalgae entering the New Zealand marine aquarium trade unregulated, but there is also the potential for them to survive in New Zealand waters.   </p>

Non-native Species Introductions, Invasions, and Biotic Homogenization in the Atlantic Forest

2021 ◽  
pp. 269-295
Author(s):  
Jean R. S. Vitule ◽  
Thiago V. T. Occhi ◽  
Laís Carneiro ◽  
Vanessa S. Daga ◽  
Fabrício A. Frehse ◽  
...  
Keyword(s):  
Atlantic Forest ◽  
Native Species ◽  
Biotic Homogenization ◽  
Species Introductions

scholarly journals Creating Cohesive, Coherent Immigration Policy

2017 ◽  
Vol 5 (1) ◽  
pp. 180-193 ◽  
Author(s):  
Pia M. Orrenius ◽  
Madeline Zavodny
Keyword(s):  
Immigration Policy ◽  
Economic Perspective ◽  
Initial Design ◽  
Unauthorized Immigration ◽  
Key Features ◽  
New Policies ◽  
Key Aspects ◽  
Over Time ◽  
Us Immigration

US immigration policy has serious limitations, particularly when viewed from an economic perspective. Some shortcomings arise from faulty initial design, others from the inability of the system to adapt to changing circumstances. In either case, a reluctance to confront politically difficult decisions is often a contributing factor to the failure to craft laws that can stand the test of time. We argue that, as a result, some key aspects of US immigration policy are incoherent and mutually contradictory —new policies are often inconsistent with past policies and undermine their goals. Inconsistency makes policies less effective because participants in the immigration system realize that lawmakers face powerful incentives to revise policies at a later date. US policies regarding unauthorized immigration, temporary visas, and humanitarian migrants offer examples of incoherence and inconsistency. This article explores key features of an integrated, coherent immigration policy from an economic perspective and how policymakers could better attempt to achieve policy consistency across laws and over time.

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