scholarly journals Patterns of Spatial Overlap between Non-Indigenous and Critically Endangered Freshwater Fishes from a Mediterranean Biodiversity Hotspot

Diversity ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 233
Author(s):  
Nicholas Koutsikos ◽  
Leonidas Vardakas ◽  
Olga-Ioanna Kalantzi ◽  
Stamatis Zogaris
Keyword(s):  
Fish Species ◽  
Natura 2000 ◽  
Freshwater Ecosystems ◽  
Ecological Impacts ◽  
Critically Endangered ◽  
Freshwater Species ◽  
Freshwater Biodiversity ◽  
Red Lists ◽  
Spatial Overlap ◽  
Mountainous Regions

Non-indigenous fish species (NIFS) can cause severe ecological impacts on the invaded ecosystems and are considered as one of the leading factors of freshwater biodiversity loss. Unraveling the spatial overlap between NIFS and critically endangered (CR) fish species can contribute to targeted conservation actions to minimize the potential negative effects. In this study, we applied geostatistical analyses to investigate the spatial overlap of NIFS against fish species that are designated under the CR status according to the IUCN and the Hellenic Zoological Society (HZS) Red Lists. Distributional data (presence–absence) from 800 records of 52 NIFS were compiled for both lentic and lotic ecosystems of Greece. Our results indicate that freshwater ecosystems under high NIFS richness were located mainly in lowland areas and often near large cities and ecosystems with well-developed commercial and recreational fisheries. On the contrary, low NIFS richness was observed in mountainous regions and in relatively small river basins. Overlapping areas of CR species with moderate to high NIFS richness (1.5–4.3 NIFS per 1 km2) were relatively high (~50%). A quarter of the overlapping areas (24.8%) fall within NATURA 2000 network, where legal management bodies could implement specialized programs to minimize the negative impacts. However, the majority of CR fish species’ distribution remains in unprotected areas indicating that protected areas should be re-designed to include areas containing freshwater species under the highest threatened category. Our findings demonstrate that whole assemblages of fishes are rapidly changing as NIFS spread into Greece and many freshwater ecosystems of outstanding biodiversity conservation value are under significant invasion pressure.

Diversity and abundance of cichlids in Ikere Gorge Reservoir, Iseyin, Oyo State, Nigeria

2021 ◽  
Vol 18 (1) ◽  
pp. 52-56
Author(s):  
S.O. Ajagbe ◽  
R.O. Ajagbe ◽  
O.S. Ariwoola ◽  
F.I. Abdulazeez ◽  
O.O. Oyewole ◽  
...  
Keyword(s):  
Fish Species ◽  
Riparian Forest ◽  
Abundant Species ◽  
Freshwater Ecosystems ◽  
Freshwater Species ◽  
Fishing Villages ◽  
Gorge Reservoir ◽  
Commercially Important ◽  
Sarotherodon Galilaeus ◽  
Fish Species Diversity

Cichlids are highly abundant and commercially important fish in freshwater ecosystems in Nigeria. This study examined the diversity and abundance of cichlids in Ikere Gorge Reservoir. Four fishing villages were randomly selected from 12 fishing villages in Ikere Gorge Reservoir as sampling sites. Cichlids were sampled randomly and examined from fishermen catch in each selected fishing village; were identified with appropriate keys; the weight and abundance of the catches were recorded. The data obtained was subjected to descriptive statistical analysis using SPSS (Version 20.0) software to determine the abundance of fish species. Fish species diversity was carried out by using Palaeontological Statistics (PAST). Eight species of cichlids were sampled in Ikere Gorge but Sarotherodon galilaeus was the most abundant species while the least abundant species was Pelmatolapia mariae. It was observed that, cichlids were  abundant in rainy season than in the dry season. Likewise, cichlids were abundant in Ikere-gorge reservoir but they have low diversity. This may be as a result of unsustainable fishing pressure and deforestation of riparian forest and sedimentation in Ikere-gorge reservoir. Therefore, to maintain sustainable fishing activities and improve cichlids population in Ikeregorge reservoir, unsustainable activities in and around Ikere Gorge reservoir should be put under control. Keywords: Cichlidae; freshwater species; dominant; Sarotherodon galilaeus; Pelmatolapia mariae.

scholarly journals The untapped potential of conservation journals to promote freshwater biodiversity

2020 ◽  
Author(s):  
Fengzhi He ◽  
Sonja C. Jähnig ◽  
Annett Wetzig ◽  
Simone D. Langhans
Keyword(s):  
Life History ◽  
Biodiversity Conservation ◽  
General Public ◽  
Marine Ecosystems ◽  
Freshwater Ecosystems ◽  
Freshwater Species ◽  
Freshwater Biodiversity ◽  
Extinct Species ◽  
Marine Turtles ◽  
Fresh Waters

AbstractFreshwater ecosystems are amongst the most diverse ecosystems on the planet. They are subject to intense and increasing threats and have a higher proportion of threatened and extinct species than terrestrial or marine realms. Concurrently, freshwater ecosystems are largely underrepresented in both conservation research and actions arguably as a consequence of less popularity and promotion. To test this assumption, we used cover images as a proxy of exposure and promotion opportunities provided by conservation journals. We collected information on cover images of 18 conservation journals from 1997 to 2016 and data on citations and Altmetric scores of papers published in them. We found that freshwater ecosystems (10.4%) were featured less often than marine (15.2%) or terrestrial (74.4%) ecosystems on covers of these journals. All 15 most featured species are from terrestrial or marine ecosystems, with 14 of them being large vertebrates such as elephants, big cats, rhinos, polar bears, and marine turtles. None of the 95 species featured more than once on the covers of conservation journals spend their whole life history in fresh waters, i.e. they are at least partly associated with terrestrial or marine ecosystems. Our results indicated that cover-featured studies received more attention from academia and the general public, i.e. showed higher citations and Altmetric scores, than non-featured ones within the same issue. By featuring freshwater species and habitats on covers, therewith providing more exposure opportunities, conservation journals hold the potential to promote biodiversity conservation in fresh waters. Scientists can help that endeavour by submitting freshwater-related photos together with their manuscripts for review, therewith providing more options for editors to portray freshwater species and habitats and to ultimately raise awareness and appreciation of freshwater life.

scholarly journals The Use of Barriers to Limit the Spread of Aquatic Invasive Animal Species: A Global Review

2021 ◽  
Vol 9 ◽  
Author(s):  
Peter E. Jones ◽  
Jeroen S. Tummers ◽  
Shams M. Galib ◽  
Darragh J. Woodford ◽  
John B. Hume ◽  
...  
Keyword(s):  
Case Studies ◽  
Native Species ◽  
Management Strategy ◽  
Freshwater Ecosystems ◽  
Ecological Impacts ◽  
Management Tool ◽  
Quantitative Aspect ◽  
Freshwater Biodiversity ◽  
Diverse Range ◽  
Wide Range

Aquatic invasive species (AIS) are one of the principal threats to freshwater biodiversity. Exclusion barriers are increasingly being used as a management strategy to control the spread of AIS. However, exclusion barriers can also impact native organisms and their effectiveness is likely to be context dependent. We conducted a quantitative literature review to evaluate the use of barriers to control animal AIS in freshwater ecosystems worldwide. The quantitative aspect of the review was supplemented by case studies that describe some of the challenges, successes, and opportunities for the use of the use of AIS exclusion barriers globally. Barriers have been used since the 1950s to control the spread of AIS, but effort has been increasing since 2005 (80% of studies) and an increasingly diverse range of AIS taxa are now targeted in a wide range of habitat types. The global use of AIS barriers has been concentrated in North America (74% of studies), Australasia (11%), and Europe (10%). Physical barriers (e.g., weirs, exclusion screens, and velocity barriers) have been most widely used (47%), followed by electric (27%) and chemical barriers (12%). Fish were the most targeted taxa (86%), followed by crustaceans (10%), molluscs (3%) and amphibians (1%). Most studies have been moderately successful in limiting the passage of AIS, with 86% of the barriers tested deterring >70% of individuals. However, only 25% of studies evaluated barrier impacts on native species, and development of selective passage is still in its infancy. Most studies have been too short (47% < 1 year, 87% < 5 years) to detect ecological impacts or have failed to use robust before-after-control-impact (BACI) study designs (only 5%). Hence, more effective monitoring is required to assess the long-term effectiveness of exclusion barriers as an AIS management tool. Our global case studies highlight the pressing need for AIS control in many ecoregions, and exclusion barriers have the potential to become an effective tool in some situations. However, the design and operation of exclusion barriers must be refined to deliver selective passage of native fauna, and exclusion barriers should only be used sparingly as part of a wider integrated management strategy.

Conservation Science Statement. The demise of New Zealand's freshwater flora and fauna: a forgotten treasure

2016 ◽  
Vol 22 (2) ◽  
pp. 110 ◽  
Author(s):  
Emily S. Weeks ◽  
Russell G. Death ◽  
Kyleisha Foote ◽  
Rosalynn Anderson-Lederer ◽  
Michael K. Joy ◽  
...  
Keyword(s):  
Best Management Practices ◽  
Water Policy ◽  
Management Practices ◽  
National Policy ◽  
Freshwater Ecosystems ◽  
Policy Statement ◽  
Freshwater Species ◽  
Freshwater Biodiversity ◽  
Water Abstraction ◽  
Endemic Flora

New Zealand’s freshwater ecosystems support a diverse and unique array of endemic flora and fauna. However, the conservation of its freshwater biodiversity is often overlooked in comparison to terrestrial and marine environments, and is under increasing threat from agricultural intensification, urbanisation, climate change, invasive species, and water abstraction. New Zealand has some of the highest levels of threatened freshwater species in the world with, for example, up to 74% of native freshwater fish listed as endangered or at risk. Threatened species are often discounted in water policy and management that is predominantly focussed on balancing water quality and economic development rather than biodiversity. We identify six clear actions to redress the balance of protecting New Zealand’s freshwater biodiversity: 1. change legislation to adequately protect native and endemic fish species and invertebrates, including those harvested commercially and recreationally; 2. protect habitat critical to the survival of New Zealand’s rare and range-restricted fish, invertebrate and plant freshwater species; 3. include river habitat to protect ecosystem health in the National Objectives Framework for the National Policy Statement for freshwater; 4. establish monitoring and recovery plans for New Zealand’s threatened freshwater invertebrate fauna; 5. develop policy and best management practices for freshwater catchments in addition to lakes and rivers to also include wetlands, estuaries, and groundwater ecosystems; and 6. establish, improve, and maintain appropriately wide riparian zones that connect across entire water catchments. We have published these recommendations as a scientific statement prepared for the Oceania Section of the Society for Conservation Biology to facilitate communication of our thoughts to as wide an audience as possible (https://conbio.org/images/content_groups/Oceania/Scientific_Statement_1_.pdf, accessed 8 February 2016).

Free-living freshwater nematodes from Brazil: checklist of genera and regional patterns of diversity

Nematology ◽  
2021 ◽  
pp. 1-14
Author(s):  
Taciana Kramer de Oliveira Pinto ◽  
Sérgio A. Netto ◽  
André Morgado Esteves ◽  
Francisco José Victor de Castro ◽  
Patricia Fernandes Neres ◽  
...  
Keyword(s):  
Benthic Communities ◽  
Extreme Environments ◽  
Freshwater Ecosystems ◽  
Freshwater Biodiversity ◽  
High Turnover ◽  
Free Living ◽  
Regional Patterns ◽  
Freshwater Nematodes ◽  
Spatial Coverage ◽  
Freshwater Habitats

Summary Brazil has one of the largest varieties of aquatic ecosystems and rich freshwater biodiversity, but these components have constantly been damaged by the expansion of unsustainable activities. Free-living nematodes are an abundant and ubiquitous component of continental benthic communities, occurring in all freshwater habitats, including extreme environments. Despite this, hardly any studies have examined the generic composition of nematodes in different latitudes and the geographic overlap of assemblages. We provide data on nematode genera from six regions in Brazil, over a north-south gradient spanning about 4000 km, encompassing rivers, coastal lakes, and reservoirs with different levels of human impact. Interpolation/extrapolation curves were generated and the zeta diversity was used to assess the overlap of nematode assemblages. Freshwater nematode assemblages comprised 54 families and 132 genera. Mononchidae, Monhysteridae, Chromadoridae, Tobrilidae and Dorylaimidae were the most diverse families. Differences in diversity and high turnover of genera were found among regions, probably related to stochastic processes. Mononchus was the only widely distributed genus. Our results revealed a high biodiversity of free-living freshwater nematodes among the regions. The limited spatial coverage of the data reveals an enormous knowledge gap in a country with 12% of the world’s freshwater resources. The lack of spatial patterns, e.g., latitudinal variation, suggests that freshwater nematode assemblages are primarily structured by the intrinsic properties of habitats. This reinforces the uniqueness of freshwater ecosystems and suggests that the nematode assemblages may be sensitive to environmental disturbances, since the limited distributions of taxa may lead to lower resilience.

scholarly journals Intraspecific variation in thermal tolerance differs between tropical and temperate fishes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
J. J. H. Nati ◽  
M. B. S. Svendsen ◽  
S. Marras ◽  
S. S. Killen ◽  
J. F. Steffensen ◽  
...  
Keyword(s):  
Climate Change ◽  
Global Warming ◽  
Intraspecific Variation ◽  
Fish Species ◽  
Thermal Tolerance ◽  
Evolutionary History ◽  
Ecological Impacts ◽  
Temperate Species ◽  
Tropical Species ◽  
Upper Thermal Tolerance

AbstractHow ectothermic animals will cope with global warming is a critical determinant of the ecological impacts of climate change. There has been extensive study of upper thermal tolerance limits among fish species but how intraspecific variation in tolerance may be affected by habitat characteristics and evolutionary history has not been considered. Intraspecific variation is a primary determinant of species vulnerability to climate change, with implications for global patterns of impacts of ongoing warming. Using published critical thermal maximum (CTmax) data on 203 fish species, we found that intraspecific variation in upper thermal tolerance varies according to a species’ latitude and evolutionary history. Overall, tropical species show a lower intraspecific variation in thermal tolerance than temperate species. Notably, freshwater tropical species have a lower variation in tolerance than freshwater temperate species, which implies increased vulnerability to impacts of thermal stress. The extent of variation in CTmax among fish species has a strong phylogenetic signal, which may indicate a constraint on evolvability to rising temperatures in tropical fishes. That is, in addition to living closer to their upper thermal limits, tropical species may have higher sensitivity and lower adaptability to global warming compared to temperate counterparts. This is evidence that freshwater tropical fish communities, worldwide, are especially vulnerable to ongoing climate change.

scholarly journals Freshwater Biodiversity Platform (FBP): an Integrated Information Management System of Freshwater Ecosystem for the Conservation and Sustainable Use of Biodiversity

2018 ◽  
Vol 2 ◽  
pp. e26490
Author(s):  
Ye-seul Kwan ◽  
Gi Cheol Lee ◽  
Sang Myeon Park ◽  
Ji Hae Lee ◽  
Jeong Su Oh
Keyword(s):  
South Korea ◽  
Management System ◽  
Sustainable Use ◽  
Information Management System ◽  
Freshwater Ecosystem ◽  
Freshwater Species ◽  
Freshwater Biodiversity ◽  
Biodiversity Data ◽  
Biological Resources ◽  
Integrated Information

Since the Nagoya Protocol on Access to genetic resources and Benefit Sharing (ABS) came into force in 2014, the conservation and assurance of national biodiversity has been internationally stressed. The Government of South Korea is exercising significant efforts to integrate and manage the information pertaining to biological resources in line with this global trend. However, connecting and sharing biodiversity data has certain challenges because the existing databases and information systems are being operated using different standards. In the present study, we established an integrated management system for freshwater biodiversity information, the Freshwater Biodiversity Platform (FBP), to support the conservation and sustainable use of biodiversity. This platform allows the management of various types of biodiversity data, such as occurrences, habitats and genetics, for freshwater species inhabiting South Korea. The data fields are based on a global biodiversity data standard, Darwin Core, and national biodiversity standards of South Korea in order to share our data more efficiently, both nationally and internationally. It is important to note that the platform deals with information related to the utilization of biological resources as well as information representing the national biodiversity. We have collected bibliographical data, such as papers and patents, from databases, including information on the use of biological resources. The data have been refined by applying a national species list of South Korea and ontology terms in (MeSH) to compile valuable information for biological industries. Furthermore, our platform is open source and is compatible with multiple language packs to facilitate the availability of biodiversity data for other countries and institutions. Currently, the Freshwater Biodiversity Platform is being used to collect and standardize various types of existing freshwater biodiversity data to build foundations for data management. Based on these data, we will improve the platform by adding new systems that can analyze and release data for public access. This platform will provide integrated information on freshwater species from the Korean Peninsula to the world and contribute to the conservation and sustainable use of biological resources.

Insights into fish-anthropogenic pressures relationships using machine learning techniques: the case of Castilla-La Mancha (Spain)

2021 ◽  
Author(s):  
Carlotta Valerio ◽  
Graciela Gómez Nicola ◽  
Rocío Aránzazu Baquero Noriega ◽  
Alberto Garrido ◽  
Lucia De Stefano
Keyword(s):  
Machine Learning ◽  
Fish Species ◽  
Conservation Status ◽  
Boosted Regression Trees ◽  
Machine Learning Techniques ◽  
Freshwater Species ◽  
Anthropogenic Pressures ◽  
La Mancha ◽  
Learning Techniques ◽  
Starting Point

<p>Since 1970 the number of freshwater species has suffered a decline of 83% worldwide and anthropic activities are considered to be major drivers of ecosystems degradation. Linking the ecological response to the multiple anthropogenic stressors acting in the system is essential to effectively design policy measures to restore riverine ecosystems. However, obtaining quantitative links between stressors and ecological status is still challenging, given the non-linearity of the ecosystem response and the need to consider multiple factors at play. This study applies machine learning techniques to explore the relationships between anthropogenic pressures and the composition of fish communities in the river basins of Castilla-La Mancha, a region covering nearly 79 500 km² in central Spain. During the past two decades, this region has experienced an alarming decline of the conservation status of native fish species. The starting point for the analysis is a 10x10 km grid that defines for each cell the presence or absence of several fish species before and after 2001. This database was used to characterize the evolution of several metrics of fish species richness over time, accounting for the species origin (native or alien), species features (e.g. pollution tolerance) and habitat preferences. Random Forest and Gradient Boosted Regression Trees algorithms were used to relate the resulting metrics to the stressor variables describing the anthropogenic pressures acting in the rivers, such as urban wastewater discharges, land use cover, hydro-morphological degradation and the alteration of the river flow regime. The study provides new, quantitative insights into pressures-ecosystem relationships in rivers and reveals the main factors that lead to the decline of fish richness in Castilla-La Mancha, which could help inform environmental policy initiatives.</p>

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