Biodiversity Of Communities Research Articles

Salinity-induced succession of phototrophic communities in a southwestern Siberian soda lake during the solar activity cycle

A variety of lakes located in the dry steppe area of southwestern Siberia are exposed to rapid climatic changes, including intra-century cycles with alternating dry and wet phases driven by solar activity. As a result, the salt lakes of that region experience significant fluctuations in water level and salinity, which have an essential impact on the indigenous microbial communities. But there are few microbiological studies that have analyzed this impact, despite its importance for understanding the functioning of regional water ecosystems. This work is a retrospective study aimed at analyzing how solar activity-related changes in hydrological regime affect phototrophic microbial communities using the example of the shallow soda lake Tanatar VI, located in the Kulunda steppe (Altai Region, Russia, southwestern Siberia). The main approach used in this study was the comparison of hydrochemical and microscopic data obtained during annual field work with satellite and solar activity data for the 12-year observation period (2011–2022). The occurrence of 33 morphotypes of cyanobacteria, two key morphotypes of chlorophytes, and four morphotypes of anoxygenic phototrophic bacteria was analyzed due to their easily recognizable morphology. During the study period, the lake surface changed threefold and the salinity changed by more than an order of magnitude, which strongly correlated with the phases of the solar activity cycles. The periods of high (2011–2014; 100–250 g/L), medium (2015–2016; 60 g/L), extremely low (2017–2020; 13–16 g/L), and low (2021–2022; 23–34 g/L) salinity with unique biodiversity of phototrophic communities were distinguished. This study shows that solar activity cycles determine the dynamics of the total salinity of a southwestern Siberian soda lake, which in turn determines the communities and microorganisms that will occur in the lake, ultimately leading to cyclical changes in alternative states of the ecosystem (dynamic stability).

Comparison of different macroinvertebrates bioassessment indices in a large near-natural watershed under the context of metacommunity theory.

The metacommunity theory proposes that community structure and biodiversity are influenced by both local processes (such as environmental filtering)and regional processes (such as dispersal). Despite the extensive use of traditional bioassessments based on species-environment relationships, the impact of dispersal processes on these assessments has been largely overlooked. This study aims to compare correlations between various bioassessment indices, including Shannon Weiner (H'), Biological Monitoring Working Party (BMWP), average score per taxon (ASPT), biotic index (BI), and EPT taxa index (EPT), based on macroinvertebrates collected from 147 sampling sites in a subtropical Chinese near-natural catchment. Modified indices were calculated by removing species strongly influenced by dispersal processes to address the influence of dispersal processes. Their relationship with environmental factors was then compared to the original indices. The study employed random forest regression (RFR) to compare the explanatory power of environmental factors using the two sets of indices. The spearman rank correlation analysis was conducted to examine the correlation between indices and environmental factors. The river health assessment was performed based on both modified and original indices. The results reveal significant differences between original and modified indices (especially H' and BI) providing a more accurate reflection of environmental conditions. Furthermore, the sensitivity of the different indices to various environmental factors varied, leading to differences in the bioassessment results between the modified and the original indices. Notably, original H', BMWP, and ASPT overestimated the bioassessment results, whereas the original BI underestimated them. These findings offer valuable insights into bioassessment and river health assessment evaluation within the catchment and other interconnected freshwater ecosystems, such as lakes, reservoirs, and wetlands. Our study underscores the importance of assessing and mitigating the impact of dispersal processes on bioassessment to obtain a more precise representation of the status of freshwater ecosystems.

Putting space into trait ecology: Trait, environment and biodiversity relationships at multiple spatial scales

Abstract Ecological processes such as environmental filtering and biotic interactions that shape species' traits and community diversity often vary with geographic distance, potentially generating spatial structures in trait variation, covariation and biodiversity data. Understanding spatial structures of trait, environment and biodiversity, or the spatial link between those factors, is fundamental to identifying spatially explicit assembly processes or biodiversity distributions in spatially heterogeneous landscapes but remains unclear. To address the issue, we gathered individual‐level leaf and diameter traits data paired with environmental data from a 4.8 ha subtropical Chinese forest and divided the forest into 25, 100, 400 and 1936 m2 grids representing contrasting spatial grains. Using Moran's correlograms, we quantified the spatial structures of trait variation and covariation, environmental conditions and biodiversity. We assessed the links between those variables using path analyses. Most variables were spatially positively autocorrelated. However, trait mean was more autocorrelated than trait variation or covariation, and intraspecific trait variation was more autocorrelated than interspecific variation. Autocorrelations in those community properties were generally weak at the large grain. Path analyses indicated positive associations between interspecific trait variation and species diversity at a very small to medium scale and a positive association between intraspecific variation and small‐scale functional diversity. Trait covariation constrained biodiversity, and multi‐trait means were negatively linked to very small‐ to medium‐scale species diversity but positively to medium‐ and large‐scale functional diversity. Patterns regarding multi‐trait community structure–environment–biodiversity associations were generally held for individual traits. However, depending on the trait, spatial scale and plant ontogenic stage, the pattern's strength changed, or occasionally, their sign reversed. We attribute spatial patterns in multi‐trait mean and covariation to scale‐dependent variation in environmental heterogeneity and trait variation to scale‐dependent competition. Synthesis. Our study provides novel insights into spatial and scale‐dependent variability in functional community structure, environment and biodiversity, and their relationships. Our results demonstrate the usefulness of spatial trait analyses in identifying scale‐dependent assembly processes or finding the importance of processes to biodiversity distributions in spatially heterogeneous landscapes. A spatially explicit perspective is thus helpful for the progress of trait ecology.

Increasing fish biodiversity in high elevation Albertan lakes in response to global environmental change over the past 50 years

IntroductionThe diversity of freshwater fishes is threatened by multiple environmental stressors, including climate change, alterations in land use, and introduction of non-native species. However, the quantification of temporal biodiversity in freshwater communities is limited. Here, we asked: i) how has alpha (species richness), beta (changes in freshwater species composition), and gamma diversity (total species diversity in a landscape) changed over time for lakes over a 50 year period?; and ii) What are the climatic, land use, and lake morphological drivers associated with higher diversity?MethodsWe assembled a database of fish species occurrence from 20 lakes across subalpine and alpine regions in Alberta from 1970-2019, in addition to lake morphological, climatic, and land use characteristics of the watersheds. ResultsWe observed an overall increase in alpha, beta, and gamma diversity from the 1970s to 2009s. However, all measures of diversity declined from 2010-2019. We found that more lakes and species assemblages were influenced by species gains, rather than species losses (with the exception of the last decade of sampling). DiscussionGenerally, we found that coolwater species were expanding and coldwater fishes were being lost throughout our study lakes. We highlight temporal heterogeneity in fish biodiversity responses to substantial environmental pressures in this region.

Linking Resource Quality and Biodiversity to Benthic Ecosystem Functions Across a Land-to-Sea Gradient

Benthic macrofauna modifies carbon and nutrient retention and recycling processes in coastal habitats. However, the contribution of benthic consumers to carbon and nutrient storage and recycling shows variation over spatial scales, as the benthic community composition changes in response to differences in environmental conditions. By sampling both shallow sandy and deep muddy sediments across a land-to-sea gradient in the northern Baltic Sea, we explored if benthic community composition, stoichiometry and process rates change in response to alterations in environmental conditions and food sources. Our results show that benthic faunal biomass, C, N, and P stocks, respiration rate and secondary production increase across the land-to-sea gradient in response to higher resource quality towards the open sea. The seston δ13C indicated terrestrial runoff and δ15N sewage input at the innermost study sites, whereas more fresh marine organic matter towards the open sea boosted benthic faunal carbon storage, respiration rate, and secondary production, that is, the generation of consumer biomass, which are essential processes for carbon turnover in this coastal ecosystem. Also, biological factors such as increasing species richness and decreasing biomass dominance of the clam Macoma balthica were significant in predicting benthic faunal C, N, and P stocks and process rates, especially at sandy sites. Interestingly, despite the variation in food sources, the benthic faunal C:N:P ratios remained stable across the gradient. Our results prove that human activities in the coastal area can influence the important links between biodiversity, structure, and process rates of benthic communities by modifying the balance of available resources, therefore hampering the functioning of coastal ecosystems.

Characterization of Insect–Pollinator Biodiversity in Agrochemical-Contaminated Agricultural Habitats

The extensive application of agrochemicals in agricultural habitats in the Southern Highlands of Tanzania (SHOT) is supposed to negatively impact the biodiversity community of insect–pollinators (INPOs). However, in light of existing knowledge, there are no studies to back up this claim. We carried out field surveys in the SHOT to assess and characterize the INPO biodiversity community in agricultural habitats and compare it with protected habitats. Direct observations, transect counts, sweep netting, and pan trap techniques were used for sampling the INPOs. Overall, the INPOs’ relative abundance (57.14%) and species diversity index in protected habitats were significantly higher compared to agricultural habitats. Similarly, we recorded a higher number of plant–INPO interactions in protected habitats than agricultural habitats. Our results suggest that, in contrast to protected habitats, agrochemicals might have driven out or discouraged INPOs from agricultural habitats, resulting in dwindling species richness, diversity, and abundance. This could be due to agrochemical contamination that impairs the quantity and quality of floral resources (nectar and pollen) required by INPOs. Alternatively, protected habitats seemed healthy and devoid of agrochemical contamination, which attracted many INPOs for foraging and nesting. Thus, in order to maintain healthy agricultural habitats and support INPO biodiversity, conservation agriculture is imperative.

Sustaining indigenous Maasai Alalili silvo-pastoral conservation systems for improved community livelihood and biodiversity conservation in East African rangelands.

Alalili system is one among the fewest remnant African indigenous and local knowledge systems that is traditionally practiced by Maasai pastoral communities to conserve certain portions of rangeland resources such as pastures and water for subsequent grazing during dry seasons. Despite its existence, East African rangelands face diverse threats from tenure security, unsustainable practices, climate, and land-use change that are notably endangering the biodiversity, livelihoods, and ecosystems in the landscape. Like other indigenous conservation systems, the sustainability of Alalili systems is being threatened, as Maasai communities are in transition due to continuous socio-cultural transformations coupled with increased livestock and human populations. We aimed to capture and document the existing occurrence and potential of Alalili systems as a pathway to improve resilience and sustain both biodiversity conservation and community livelihoods in rangeland areas of northern Tanzania. A cross-sectional research design was applied with the adoption of both purposive and stratified random sampling techniques to distinctively characterize the Alalili systems by land use and tenure types. Our results identified the existence of both communal and private Alalili systems. Their sizes varied significantly across types (t = 4.4646, p < 0.001) and land uses (F = 3.806, df = 3, p = 0.0123). While many (82%) of these Alalili systems are found in the communal land, our observations show a re-practice of Alalili systems in the private land is considered largely a re-emerging strategy for securing pastures in the face of local and global change. More than half (73%) of Alalili systems were found within game-controlled areas with little representation (about 8%) in non-protected land. Therefore, their sustainability is threatened by anthropogenic and climatic pressures, making their persistence more vulnerable to extinction. We recommend mainstreaming these practices into core pasture production and management areas, facilitating their reinforcement into policy and practices.

National assessment on the status, trends and impacts of marine non-indigenous species for the European Union marine strategy framework directive

The Marine Strategy Framework Directive (MSFD) of the European Union aims to enhance the protection of marine ecosystems by assessing Good Environmental Status using several descriptors. Descriptor 2 of the MSFD states that the status of marine non-indigenous species (NIS) should be assessed using specified criteria regarding newly introduced NIS, abundance, and spatial distribution of established NIS, as well as proportions of native species groups adversely altered due to NIS. The current study presents a national NIS indicator assessment for the six sub-basins associated with the Finnish marine waters. The study additionally aimed to develop a methodology to assess changes in native species communities over time. A new biodiversity index was created for this purpose by combining the Gini-Simpson index, and species and phyla richness into a Community Biodiversity Index (CBI). CBI was calculated to measure changes in biodiversity within the soft-bottom benthic communities of the study area, and correlation analyses were conducted between the index scores and NIS proportion. Overall, 34 NIS have been recorded from the Finnish marine waters by 2022, and more than half of them have arrived since 1992. Spatial distribution of three established non-indigenous taxa (Marenzelleria spp., Cercopagis pengoi and Neogobius melanostomus) has expanded during the latest assessment periods and nowadays cover most of the national marine waters. Meanwhile, abundance of Marenzelleria spp. in benthic communities has increased heavily in most sub-basins. The study outcomes indicated that NIS proportion correlated significantly with the CBI within the soft-bottom benthic communities. This correlation was significantly negative for the samples with a higher NIS proportion than the median, suggesting that when NIS became more dominant, biodiversity of the communities decreased. The current study provides an applicable method to evaluate changes in biodiversity for various species groups, and how to link them to changes in the distribution and abundance of established NIS. It can be concluded that the national biological monitoring program has severe temporal and spatial gaps, as the national monitoring data enabled the assessment on native species groups, adversely altered due to NIS to be completed only for one species group, soft-bottom macrozoobenthos. Most importantly, the study emphasised the crucial need for management actions to prevent further NIS introductions.

Influence of a new fishpond design on invertebrate community biodiversity and secondary production

Influence of a new fishpond design on invertebrate community biodiversity and secondary production

2017–2020年广东南岭典型植被类型木本植物物种组成数据集

Plant species composition is a vital indicator for studying the structure and functioning of forest ecosystems. It constitutes an important component of the China Ecosystem Research Network (CERN) and the long-term monitoring of terrestrial ecosystem biological elements. It can be utilized to assess and monitor biodiversity levels, environmental changes, and ecosystem responses. It holds utmost significance for natural resource management and land-use planning, providing crucial foundations for scientific research, policy-making, and ecological conservation. Nanling, as a significant ecological barrier in China, harbors the largest area of forests at the same latitude. It encompasses various vegetation types, including subtropical evergreen broad-leaved forests, subtropical mixed coniferous and broad-leaved forests, and subtropical dwarf evergreen broad-leaved forests. Following the monitoring specifications for terrestrial ecosystem biological elements, this paper presents the original data of all woody plant individuals with a diameter at breast height (DBH) ≥ 1 cm, including their species names, DBH, height, and other relevant information. These data were obtained through two consecutive census surveys conducted by the Guangdong Nanling Forest Ecosystem National Field Scientific Observation Research Station from 2017 to 2020. After meticulous data organization, quality control, and evaluation, the dataset provides detailed information on typical forest communities in Nanling, including plot numbers, vegetation types, species names, Latin names, abundance, relative abundance, relative dominance, relative frequency, importance value, and year of survey. This dataset serves as local data for in-depth investigation into biodiversity, community structure, and functions of forest communities in Nanling. Moreover, it aims to provide fundamental support for forest management, environmental protection, natural resource management, and sustainable development in the region.

Towards interpretable learned representations for ecoacoustics using variational auto-encoding

Ecoacoustics is an emerging science that seeks to understand the role of sound in ecological processes. Passive acoustic monitoring is being used to collect vast quantities of soundscape audio recordings to study variations in acoustic community and monitor biodiversity. However, extracting relevant information from soundscape recordings is non-trivial. Recent approaches to machine-learned acoustic features appear promising but are limited by at least three issues: inductive biases, lack of interpretability and crude temporal integration. In this paper we introduce a novel self-supervised representation learning algorithm for ecoacoustics - a convolutional Variational Auto-encoder (VAE) - and directly address these shortcomings. Firstly, we train the network on soundscape recordings from temperate and tropical field sites along a gradient of ecological degradation to provide a more relevant inductive bias than prior approaches. Secondly, we present a new method that allows interpretation of the latent space for the first time, giving insight into the basis of classification. Thirdly, we advance existing methods for temporal aggregation of learned embeddings by encoding latent features as a distribution over time. Under our approach to increase interpretability, we provide insight into how learned features drive habitat classification for the first time: inspection of latent space confirms that varying combinations of biophony, geophony and anthrophony are used to infer sites along a degradation gradient. Our novel temporal encoding method increases sensitivity to periodic signals and improves on previous research that uses time-averaged representations for site classification. This approach also reveals the contribution of hardware-specific frequency response that create a potential bias; we demonstrate how a simple linear transformation can be used to mitigate the effect of hardware variance on the learned representation under our approach. Our novel approach paves the way for development of a new class of deep neural networks that afford more interpretable learned ecoacoustic representations to advance both fundamental and applied science and support global conservation efforts.

Biodiversity and core microbiota of key-stone ecological clusters regulate compost maturity during cow-dung-driven composting

The primary objectives of this study were to explore the community-level succession of bacteria, fungi, and protists during cow-dung-driven composting and to elucidate the contribution of the biodiversity and core microbiota of key-stone microbial clusters on compost maturity. Herein, we used high-throughput sequencing, polytrophic ecological networks, and statistical models to visualize our hypothesis. The results showed significant differences in the richness, phylogenetic diversity, and community composition of bacteria, fungi, and eukaryotes at different composting stages. The ASV191 (Sphingobacterium), ASV2243 (Galibacter), ASV206 (Galibacter), and ASV62 (Firmicutes) were the core microbiota of key-stone bacterial clusters relating to compost maturity; And the ASV356 (Chytridiomycota), ASV470 (Basidiomycota), and ASV299 (Ciliophora) were the core microbiota of key-stone eukaryotic clusters relating to compost maturity based on the data of this study. Compared with the fungal taxa, the biodiversity and core microbiota of key-stone bacterial and eukaryotic clusters contributed more to compost maturity and could largely predict the change in the compost maturity. Structural equation modeling revealed that the biodiversity of total microbial communities and the biodiversity and core microbiota of the key-stone microbial clusters in the compost directly and indirectly regulated compost maturity by influencing nutrient availability (e.g., NH4+-N and NO3−-N), hemicellulose, humic acid content, and fulvic acid content, respectively. These results contribute to our understanding of the biodiversity and core microbiota of key-stone microbial clusters in compost to improve the performance and efficiency of cow-dung-driven composting.

Influence of water color and catchment lake cover on stream macroinvertebrate communities: Ecological insights into browning effects

Browning of streams due to increased export of dissolved organic carbon (DOC) and iron has been observed in vast areas of the northern hemisphere with likely adverse ecological effects. Lake basins in stream catchments can moderate DOC export and influence stream communities, which complicates understanding of the effects of DOC. In this study, we explored the independent and interactive effects of water color (proxy for DOC and iron) and catchment lake cover on benthic macroinvertebrate communities in 94 medium-sized boreal forest streams. We first investigated the role of lake basins and other catchment characteristics in controlling water color. We then studied the effects of water color and catchment lake cover on macroinvertebrate community composition, biodiversity, and functional feeding traits. Water color correlated negatively with catchment lake cover, whereas the correlation with peatland cover and drainage intensity was positive. PERMANOVA and GLS analyses indicated that both color and catchment lake cover had a distinct independent effect on invertebrate community composition and community attributes, without significant interactions. Color had an independent negative effect on EPT (Ephemeroptera, Plecoptera, Trichoptera) taxa richness irrespective of lake cover. Increasing water color had negative effect on relative abundance of grazer, but no significant effect on shredder trait, while lake cover had a negative effect on both of the traits. Lake cover exhibited a negative influence on collector-gatherers, and a positive effect on filter feeders, while the predators were positively affected by both factors. The results highlight that water color influences the community structure of boreal stream ecosystems, and the effects are similar regardless of catchment lake cover. Mitigation measures should be emphasized, aimed at reducing DOC and iron runoff, in land use planning and river basin management.

Diversity and function of viral AMGs associated with DNA biosynthesis in the Napahai plateau wetland

ABSTRACT Viruses play an important role in microbial community structure and biodiversity by lysing host cells, and can also affect host metabolic pathways by expressing auxiliary metabolic genes (AMGs). As a unique low-latitude, high-altitude seasonal plateau wetland in China, Napahai has high research value. However, studies on the genetic diversity of AMGs and viruses associated with DNA biosynthesis have not been reported. Based on metagenomics, with the phylogenetic tree, PCoA, and α diversity analysis, we found that three DNA biosynthesis-related viral AMGs (cobS, mazG, and purM) in the Napahai plateau wetland were rich in genetic diversity, uniqueness, and differences compared with other habitats and host sources. Through the KEGG metabolic pathway and metabolic flow analysis of Pseudomonas mandelii (SW-3) and phage (VSW-3), the AMGs (cobS, mazG, and purM) genes of the three related viruses involved in DNA biosynthesis were upregulated and their expression increased significantly. In general, we systematically described the genetic diversity of AMGs associated with DNA biosynthesis in plateau wetland ecosystems and clarified the contribution of viral AMGs in the Napahai plateau wetland to DNA biosynthesis, as well as the changes of metabolites and genes. It further expands the understanding of phage-host interactions, which is of great significance for further revealing the role of viral AMGs in the biological evolution and biogeochemical cycle of wetland ecosystems.

Environmental selection and gene flow jointly determine the population genetic diversity and structure of Diaphanosoma dubium along a watershed elevation

Biodiversity of local communities has been found to generally decrease with elevation. However, the elevational patterns of intraspecific genetic diversity remain unclear, especially in passive dispersers and species with short life histories. In this study, we investigated the populations of a tropical dominant Cladoceran, Diaphanosoma dubium, along elevation in the largest watershed of South China. The studied populations were grouped into four regional groups based on elevation and habitat connectivity. No significant elevation pattern was observed for mitochondrial genetic diversity, but nuclear diversity was influenced by habitat type. The haplotype network showed a radial pattern with a common haplotype at the centre, and many private haplotypes existed in each regional group. Four clusters of D. dubium populations were identified and exactly corresponding to the four investigated regions, indicating a strong spatial genetic structure. Weak but significant isolation by distance (IBD) supported the critical role of environmental selection with elevation. Precipitation significantly explained population genetic variation at the watershed scale. Bidirectional gene flow was a common pattern that occurred among the four regional groups. Our results highlight that habitat selection with gene flow plays an important role in shaping the genetic pattern of tropical freshwater Cladocera along an elevational gradient.

Exploration and Retrieval of Virus-Related Molecular Data Using ExTaxsI: The Monkeypox Use Case.

Retrieval and visualization of biological data are essential for understanding complex systems. With the increasing volume of data generated from high-throughput sequencing technologies, effective and optimized data visualization tools have become indispensable. This is particularly relevant in the COVID-19 postpandemic period, where understanding the diversity and interactions of microbial communities (i.e., viral and bacterial) constitutes an important asset to develop and plan suitable interventions.In this chapter, we show the usage and the potentials of ExTaxsI (Exploring Taxonomy Information) tool to retrieve viral biodiversity data stored in National Center for Biotechnology Information (NCBI) databases and create the related visualization. In addition, by integrating different functions and modules, the tool generates relevant types of visualization plots to facilitate the exploration of microbial biodiversity communities useful to deep dive into ecological and taxonomic relationships among different species and identify potential significant targets.Using the Monkeypox virus as a case study, this work points out significant perspectives on biological data visualization, which can be used to gain insights into the ecology, evolution, and pathogenesis of viruses. Accordingly, we show the potentiality of ExTaxsI to organize and describe the available/downloaded data in an easy, simple, and interpretable way allowing the user to interact dynamically with the visualization plots through specific filters, zoom, and explore functions.

Land Snails at the Zoo: A Biodiverse Community with Conservation and Educational Potential

The combination of animals and plants in zoological gardens provides the opportunity for conservation within the grounds. An example is pollination gardens that support free-moving butterflies and bees. Pollination gardens and other areas with plants also support a wide range of other non-captive animals, including soil-associated invertebrates. This study targeted land snails, a species-rich group that links the brown decomposition food web and the plant-based web that is preyed upon by fireflies and birds, among others. A survey of 24 sites within the Oklahoma City Zoo and Botanical Garden revealed a diverse snail fauna of 23 species. The majority were native species but included 10 non-native species that are common regional urban species, likely introduced through the plant trade. No distributional pattern of snails was evident, probably because of the similar management scheme throughout the zoo. Snails and other observed soil-associated invertebrates (e.g., isopods, millipedes, and earthworms) support non-captive birds and other animals. Lightly managed areas with leaf litter and downed wood are especially conducive to snails and other soil-associated invertebrates and are nesting sites for bees. These communities can form conservation demonstration areas that can be the basis of educational programs, including outreach programs.

Biodiversity and genetic connectivity of Brachyura and Anomura (Decapoda) from artificial reefs in the Gulf of Mexico

Abstract Artificial reefs act as islands of biodiversity that provide substrate where sessile organisms can settle and mobile invertebrates and fishes can find shelter and food. Though these structures are common and widespread in the Gulf of Mexico, their community composition is not well understood. We aimed to ameliorate understanding of the invertebrate communities living on artificial reefs in the northeastern Gulf of Mexico by using molecular techniques and morphological examination to describe the biodiversity and genetic connectivity of crabs (Infraorders Anomura and Brachyura) living on and among artificial reefs near Pensacola, FL, USA. Specimens (N = 1,241) were collected from six artificial reefs using Autonomous Reef Monitoring Structures (ARMS) after four, six, and ten months of submergence, respectively, and were identified using DNA barcoding and morphological examination. Spatial and temporal trends in biodiversity were examined by comparing Hill-Shannon and Hill-Simpson diversities, richness, and canonical correspondence analysis. Population genetic analyses were performed on the two most commonly recovered species, Pseudomedaeus agassizii (A. Milne-Edwards, 1880) and Hexapanopeus paulensis (Rathbun, 1930). A total of 11 taxa were identified, and artificial reef shape was found to be influential in shaping spatial patterns of biodiversity. Species turnover was common across the ten months of sampling, and richness peaked at the ten-month mark. Population genetics revealed that there is high gene flow between the six sampling locations. This study is the first to describe the biodiversity of crab communities on artificial reefs in the northeastern Gulf of Mexico.

Exploring visual methods for monitoring marine non-indigenous species colonizing artificial structures in the Madeira archipelago (NE Atlantic)

The introduction of non-indigenous species (NIS) poses a significant threat to biodiversity in coastal communities globally, with maritime traffic serving as a primary vector for introducing these species into new habitats. Managing potential new marine invasions begins in harbours and marinas, where artificial structures are the first step towards establishing new habitats. In this study, we aimed to examine and compare the performance of three methods: Plate, Photo quadrate, and a new Video approach, using image analysis for monitoring fouling communities in artificial structures, with a specific focus on NIS in marinas. Additionally, we evaluated attributes for each method, including cost, area, deployment/sampling time, and logistics, to determine the most reliable, efficient, and affordable method with respect to species richness (S) and cover (N). The video (VID) method performed similarly to the plate (PLA) method in species identification and outperformed the photo (PHO) method. The VID method represents a novel and faster approach for monitoring NIS in artificial structures, offering several advantages. It allows data gathering that can be performed by non-taxonomic experts, facilitating rapid detection and intervention in managing marine invasions in port environments. By assessing the effectiveness of these methods, we sought to contribute to developing improved strategies and faster approaches for monitoring and mitigating the impact of NIS in coastal communities.

When good turns to bad and alien predators appear: The dynamics of biodiversity change in boreal waterbird communities

Temporal patterns of biodiversity are often difficult to interpret because of our limited understanding of how communities vary through time and how processes drive this variation. A further challenge with dynamic systems is choosing an appropriate baseline against which biodiversity change is judged. We used abundance time series of breeding waterbirds in eutrophic lakes in Finland for 1946–2022 to study the dynamics of biodiversity change in local communities and the relative role of two presumed main drivers, i.e. eutrophication and alien predators, in contributing to historical and recent trends in local abundances and biodiversity. We set the cut-off for the historical and recent study periods in the mid-1980 s, because the systematic monitoring of breeding waterbirds in Finland started in 1986 and recent analyses of biodiversity change and population trends in European boreal waterbird communities are mainly based on time series and data gathered since 1986. Both species richness and the total abundance of waterbirds in local communities showed contrasting trends between historical (gathered before the mid-1980 s) and current (gathered after the mid-1980 s) community time series, with the current time series indicating a decline and the historical time series indicating an increase. The abundances of habitat specialists (species preferring eutrophic lakes) and habitat generalists (species using both eutrophic and oligotrophic lakes) showed a corresponding difference between the current and historical time series. The local extinction rates were higher among habitat specialists than among habitat generalists. The trend indices for wetland-nesting species (highly vulnerable to predation by two alien species (the raccoon dog, Nyctereutes procyonoides, and American mink, Neovison vison) in terms of nest site) abundances were more negative than the trend indices of species nesting further away from waterbodies (less vulnerable to predation by two alien species). In addition, bottom-feeding species (presumably more sensitive to negative impacts of eutrophication) did not show more negative population trends than surface-feeding species (presumably less sensitive to negative impacts of eutrophication). Regardless of equal sensitivity to negative impacts of eutrophication, two species highly vulnerable to two alien predators showed more negative population trends than a less vulnerable species. The results suggest that increased predation has been an important driver of the population and biodiversity declines in the studied waterbird communities. The mid-1980 s may not provide an ecologically appropriate baseline against which changes in the populations and biodiversity of boreal waterbird communities are judged.