scholarly journals Highest Composition Dissimilarity among Phytoplankton Communities at Intermediate Environmental Distances across High-Altitude Tropical Lakes

Water ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1378
Author(s):  
Alonso Cartuche ◽  
Kalina M. Manoylov ◽  
Bastiaan W. Ibelings ◽  
Patrick Venail
Keyword(s):  
Community Structure ◽  
High Altitude ◽  
Community Composition ◽  
Geographic Distance ◽  
Freshwater Ecosystems ◽  
Distance Decay ◽  
Tropical Lakes ◽  
Phytoplankton Composition ◽  
High Altitude Lakes ◽  
Phytoplankton Communities

Tropical high-altitude lakes are vital freshwater ecosystems for the functioning and dynamics of tropical high-altitude wetlands called páramos, found at over 3300 m above sea level. They play a major role in the hydrogeological cycle and provide important hydrological services such as water storage, and yet they are understudied. Describing the patterns and processes of community composition in these lakes is required to better understand the consequences of their degradation by human activities. In this study we tested the geographical and environmental components of distance–decay relationships in the phytoplankton structure across 24 tropical high-altitude lakes from Southern Ecuador. Phytoplankton composition at the phyla level showed high among-lake variation in the tropical high-altitude lakes from Tres Lagunas. We found no links, however, between the geographic distance and phytoplankton composition. On the contrary, we observed some environmentally related patterns of community structure like redox potential, altitude, water temperature, and total phosphorus. The absence of support for the distance–decay relationship observed here can result from a conjunction of local niche-based effects and dispersal limitations. Phytoplankton community composition in the Tres Lagunas system or any other ecosystem may be jointly regulated by niche-based and neutral forces that still need to be explored. Despite not proving a mechanistic explanation for the observed patterns of community structure, we hope our findings provide understanding of these vulnerable and vital ecosystems. More studies in tropical high-altitude lakes are urgently required.

scholarly journals Species composition of introduced and natural minnow populations of the Phoxinus cryptic complex in the westernmost part of the Po River Basin (north Italy)

2020 ◽  
Author(s):  
Vanessa De Santis ◽  
Giovanni B. Delmastro ◽  
Isabella Vanetti ◽  
J. Robert Britton ◽  
Serena Zaccara
Keyword(s):  
High Altitude ◽  
Cryptic Species ◽  
River Basin ◽  
Anthropogenic Activities ◽  
Fish Communities ◽  
Freshwater Ecosystems ◽  
Po River ◽  
Lowland Streams ◽  
High Altitude Lakes ◽  
Po River Basin

AbstractInvasive alien species are a major driver of biodiversity loss, with their impacts potentially more intense when complexes of cryptic species are involved. In freshwaters, the anthropogenic manipulation of fish communities has resulted in altered fish communities, and in Europe has increased the complexity of Phoxinus species assemblages. Here, we investigated the Phoxinus communities of the westernmost part of the Po river basin, where adjacent freshwater ecosystems (Alpine high-altitude lakes and lowland streams) are representative of different management strategies (i.e. manipulated fish communities via stocking in Alpine lakes vs. natural populations in streams). We tested the genetic composition of the cryptic Phoxinus populations inhabiting these waters, as the species are morphologically indistinct. Sequences of the mitochondrial cytochrome oxidase I (COI) were obtained from 239 specimens, with the results indicating that 17 Alpine high-altitude lakes are now populated by a complex of Phoxinus species, comprising P. septimaniae (native to the Mediterranean area of France), P. csikii (native to the Central Balkans) and P. lumaireul (native to the North Adriatic Sea basins). Their introduction resulted from their use as angling live baits. Minnow populations in lowland streams were primarily comprised of native P. lumaireul, with only a single P. csikii specimen detected. While nuclear sequences of the recombination activating gene 1 (RAG1) marker were not useful for tracking the presence of alien alleles in these stream populations, the COI data emphasised the importance of using molecular tools to investigate cryptic species complexes that have been modified by anthropogenic activities.

Herbivory in variable environments: an experimental test of the effects of vertical mixing and Daphnia on phytoplankton community structure

2001 ◽  
Vol 58 (7) ◽  
pp. 1371-1379 ◽  
Author(s):  
Beatrix E Beisner
Keyword(s):  
Community Structure ◽  
Phytoplankton Community ◽  
Size Structure ◽  
Vertical Mixing ◽  
Community Diversity ◽  
Temporal Heterogeneity ◽  
Phytoplankton Community Structure ◽  
Phytoplankton Composition ◽  
Encounter Rates ◽  
Phytoplankton Communities

Phytoplankton communities in lakes are exposed to different within-season frequencies of heterogeneity in resource supply because of wind-induced vertical mixing. Effects of such heterogeneity, in conjunction with herbivory, on phytoplankton community structure have rarely been simultaneously examined, despite the fact that each factor can have large effects on phytoplankton composition and diversity. This study uses replicated oligotrophic mesocosms to examine the effects of herbivory and different scales of temporal heterogeneity in deepwater mixing. The pattern of vertical mixing alone had minor effects on phytoplankton community diversity and composition. The herbivore Daphnia caused a shift in phytoplankton composition to less edible types, based mainly on morphological features (spiny shapes and trichomes on cell walls) rather than size structure alone. Phytoplankton richness depended jointly on mixing frequency and large Daphnia biomasses. When systems were well mixed, with high encounter rates between predator and prey populations, phytoplankton community richness was lowest. By contrast, the systems that were least often mixed had highest richness. These results are related to limited encounter rates with infrequent mixing and to the availability of refuges from predation. Responses to different scales of temporal heterogeneity in these oligotrophic phytoplankton communities depend more on Daphnia feeding than on resource pulsing.

Dissolved oxygen and temperature best predict deep-sea fish community structure in the Gulf of California with climate change implications

2020 ◽  
Vol 637 ◽  
pp. 159-180
Author(s):  
ND Gallo ◽  
M Beckwith ◽  
CL Wei ◽  
LA Levin ◽  
L Kuhnz ◽  
...  
Keyword(s):  
Climate Change ◽  
Community Structure ◽  
Community Composition ◽  
Environmental Conditions ◽  
Deep Sea ◽  
Gulf Of California ◽  
Fish Community ◽  
Demersal Fish ◽  
Fish Community Structure ◽  
Explained Variance

Natural gradient systems can be used to examine the vulnerability of deep-sea communities to climate change. The Gulf of California presents an ideal system for examining relationships between faunal patterns and environmental conditions of deep-sea communities because deep-sea conditions change from warm and oxygen-rich in the north to cold and severely hypoxic in the south. The Monterey Bay Aquarium Research Institute (MBARI) remotely operated vehicle (ROV) ‘Doc Ricketts’ was used to conduct seafloor video transects at depths of ~200-1400 m in the northern, central, and southern Gulf. The community composition, density, and diversity of demersal fish assemblages were compared to environmental conditions. We tested the hypothesis that climate-relevant variables (temperature, oxygen, and primary production) have more explanatory power than static variables (latitude, depth, and benthic substrate) in explaining variation in fish community structure. Temperature best explained variance in density, while oxygen best explained variance in diversity and community composition. Both density and diversity declined with decreasing oxygen, but diversity declined at a higher oxygen threshold (~7 µmol kg-1). Remarkably, high-density fish communities were observed living under suboxic conditions (<5 µmol kg-1). Using an Earth systems global climate model forced under an RCP8.5 scenario, we found that by 2081-2100, the entire Gulf of California seafloor is expected to experience a mean temperature increase of 1.08 ± 1.07°C and modest deoxygenation. The projected changes in temperature and oxygen are expected to be accompanied by reduced diversity and related changes in deep-sea demersal fish communities.

scholarly journals 18S rRNA Analysis Reveals High Diversity of Phytoplankton with Emphasis on a Naked Dinoflagellate Gymnodinium sp. at the Han River (Korea)

Diversity ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 73
Author(s):  
Buhari Lawan Muhammad ◽  
Taehee Kim ◽  
Jang-Seu Ki
Keyword(s):  
Water Quality ◽  
Quality Management ◽  
18S Rrna ◽  
Water Quality Management ◽  
Operational Taxonomic Unit ◽  
Amplicon Sequencing ◽  
Freshwater Ecosystems ◽  
Reservoir Area ◽  
Han River ◽  
Phytoplankton Communities

Biomonitoring of phytoplankton communities in freshwater ecosystems is imperative for efficient water quality management. In the present study, we present the seasonal diversity of phytoplankton from the non-reservoir area of the Han River (Korea), assessed using the 18S rRNA amplicon sequencing. Our results uncovered a considerably high eukaryotic diversity, which was predominantly represented by phytoplankton in all the seasons (38–63%). Of these, the diatoms, Cyclostephanos tholiformis, Stephanodiscus hantzschii, and Stephanodiscus sp., were frequently detected in spring and winter. Interestingly, for the first time in the Han River, we detected a large number of operational taxonomic unit (OTU) reads belonging to the naked dinoflagellate Gymnodinium sp., which dominated in autumn (15.8%) and was observed only in that season. Molecular cloning and quantitative real-time polymerase chain reaction (PCR) confirmed the presence of Gymnodinium sp. in the samples collected in 2012 and 2019. Moreover, a comparison of the present data with our previous data from a reservoir area (Paldang Dam) revealed similar patterns of phytoplankton communities. This molecular approach revealed a prospective toxic species that was not detected through microscopy. Collectively, resolving phytoplankton communities at a level relevant for water quality management will provide a valuable reference for future studies on phytoplankton for environmental monitoring.

scholarly journals Timing of sea ice retreat can alter phytoplankton community structure in the western Arctic Ocean

2014 ◽  
Vol 11 (7) ◽  
pp. 1705-1716 ◽  
Author(s):  
A. Fujiwara ◽  
T. Hirawake ◽  
K. Suzuki ◽  
I. Imai ◽  
S.-I. Saitoh
Keyword(s):  
Community Structure ◽  
Sea Ice ◽  
Arctic Ocean ◽  
Phytoplankton Community ◽  
Phytoplankton Community Structure ◽  
Western Arctic Ocean ◽  
Phytoplankton Communities ◽  
Ice Retreat ◽  
Western Arctic ◽  
Sea Ice Retreat

Abstract. This study assesses the response of phytoplankton assemblages to recent climate change, especially with regard to the shrinking of sea ice in the northern Chukchi Sea of the western Arctic Ocean. Distribution patterns of phytoplankton groups in the late summers of 2008–2010 were analysed based on HPLC pigment signatures and, the following four major algal groups were inferred via multiple regression and cluster analyses: prasinophytes, diatoms, haptophytes and dinoflagellates. A remarkable interannual difference in the distribution pattern of the groups was found in the northern basin area. Haptophytes dominated and dispersed widely in warm surface waters in 2008, whereas prasinophytes dominated in cold water in 2009 and 2010. A difference in the onset date of sea ice retreat was evident among years–the sea ice retreat in 2008 was 1–2 months earlier than in 2009 and 2010. The spatial distribution of early sea ice retreat matched the areas in which a shift in algal community composition was observed. Steel-Dwass's multiple comparison tests were used to assess the physical, chemical and biological parameters of the four clusters. We found a statistically significant difference in temperature between the haptophyte-dominated cluster and the other clusters, suggesting that the change in the phytoplankton communities was related to the earlier sea ice retreat in 2008 and the corollary increase in sea surface temperatures. Longer periods of open water during the summer, which are expected in the future, may affect food webs and biogeochemical cycles in the western Arctic due to shifts in phytoplankton community structure.

scholarly journals Perspectives for an integrated understanding of tropical and temperate high-mountain lakes

2016 ◽  
Vol 75 (s1) ◽  
Author(s):  
Jordi Catalan ◽  
John C. Donato Rondón
Keyword(s):  
Global Change ◽  
Freshwater Ecosystems ◽  
Mountain Lakes ◽  
Molecular Techniques ◽  
Mountain Lake ◽  
Tropical Lakes ◽  
High Mountain ◽  
Essential Difference ◽  
High Mountain Lakes ◽  
High Mountain Lake

<p>High mountain lakes are extreme freshwater ecosystems and excellent sentinels of current global change. They are likely among the most comparable ecosystems across the world. The largest contrast occurs between lakes in temperate and tropical areas. The main difference arises from the seasonal patterns of heat exchange and the external loadings (carbon, phosphorus, metals). The consequence is a water column structure based on temperature, in temperate lakes, and oxygen, in tropical lakes. This essential difference implies that, in tropical lakes, one can expect a more sustained productivity throughout the year; a higher nutrient internal loading based on the mineralization of external organic matter; higher nitrification-denitrification potential related to the oxyclines; and a higher metal mobilization due to the permanently reduced bottom layer. Quantifying and linking these and other biogeochemical pathways to particular groups of organisms is in the current agenda of high-mountain limnology. The intrinsic difficulties of the taxonomic study of many of the organisms inhabiting these systems can be now overcome with the use of molecular techniques. These techniques will not only provide a much less ambiguous taxonomic knowledge of the microscopic world, but also will unveil new biogeochemical pathways that are difficult to measure chemically and will solve biogeographical puzzles of the distribution of some macroscopic organism, tracing the relationship with other areas. Daily variability and vertical gradients in the tropics are the main factors of phytoplankton species turnover in tropical lakes; whereas seasonality is the main driver in temperate communities. The study of phytoplankton in high-mountain lakes only makes sense in an integrated view of the microscopic ecosystem. A large part of the plankton biomass is in heterotrophic, and mixotrophic organisms and prokaryotes compete for dissolved resources with eukaryotic autotrophs. In fact, high-mountain lake systems are excellent model ecosystems for applying an investigation linking airshed to sediments functional views. Additionally, the study of the mountain lakes districts as functional metacommunity units may reveal key differences in the distribution of organisms of limited (slow) dispersal. We propose that limnological studies at tropical and temperate high mountain lakes should adhere to a common general paradigm. In which biogeochemical processes are framed by the airshed-to-sediment continuum concept and the biogeographical processes in the functional lake district concept. The solid understanding of the fundamental limnological processes will facilitate stronger contributions to the assessment of the impacts of the on-going global change in remote areas.</p>

scholarly journals Struktur Komunitas Fitoplankton di Kolam Bekas Pertambangan Batubara Desa Kampung Baru Kecamatan Cempaka

BIOSCIENTIAE ◽  
2021 ◽  
Vol 17 (2) ◽  
pp. 37
Author(s):  
Sukoco Sukoco ◽  
Gunawan Gunawan ◽  
Muhamat Muhamat
Keyword(s):  
Community Structure ◽  
Coal Mining ◽  
Sampling Method ◽  
Diversity Index ◽  
Pool Analysis ◽  
Fertility Rate ◽  
The State ◽  
Purposive Sampling ◽  
Phytoplankton Communities ◽  
Average Abundance

This study aims to determine the structure of phytoplankton communities in the pool are former coal mining Desa Kampung Baru Kecamatan Cempaka which include abundance, diversity, uniformity and dominance. Phytoplankton samples taken in two pools with a purposive sampling method with a three-point shooting at each pond. Sampling was performed three times. Phylum of phytoplankton were identified in both pools as much as 2 phylum (Chloropyta and Chrysopita) with 17 genera. Average abundance of phytoplankton in the first pool of 7174 ind / liter and 6873 ind / liter in the second pool. The average diversity index of phytoplankton in the first pool of 1.540 and 1.621 in the second pool. Average uniformity index of phytoplankton in the first pool of 0622 and 0.623 in the second pool. The average index of phytoplankton dominance in the first pool of 0271 and 0250 in the second pool. Analysis of community structure (abundance, diversity, uniformity and dominance) shows the condition of the two ponds in the state is quite stable and capable of supporting life inside the phytoplankton. Where the pool in the fertility rate is the level of contamination is, the conditions included in the category of individuals spread more evenly and there are no species that dominate other species in the extreme.

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