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Although position within the estuarine landscape is known to influence structural characteristics and ecological functioning of many habitats, the influence of position on subtidal oyster reef characteristics and functioning is relatively understudied. This study assessed habitat provision by oysters and benthic macrofauna on subtidal bar and patch oyster reefs within the northwestern Gulf of Mexico estuary. Bar reefs had greater and more variable oyster density, biomass, and volume, as well as dead shell material, compared to patch reefs. Benthic macrofaunal community composition differed between reef types, with bar reefs hosting 11× and 30× higher biomass of Porcellanidae and Ampithoidae crustaceans, and patch reefs supporting 34× and 47× higher biomass of Eunicidae annelids and Leptocheliidae crustaceans. The environmental variables most highly correlated with macrofaunal communities on both bar and patch reefs were sediment chlorophyll-a, volume of dead oyster shells, and depth. Despite differences in structural characteristics and position within the estuarine landscape, subtidal oyster reefs are often managed as a single habitat type. Our findings emphasize the importance of considering location in oyster reef conservation and restoration efforts to better predict and optimize faunal provision outcomes. [ABSTRACT FROM AUTHOR]

Barshore is a small village in the Pishin District, Balochistan, Pakistan, with dry summers and cold rainy winters. This is an agrarian region, mostly with orchards of various fruit trees. This study investigated the physico-chemical properties and macrofauna of soils under various agricultural management practices of this region. The concentrations of soil organic matter (SOM), soil organic carbon (SOC), nutrients, pH, electrical conductivity, soil texture, and the abundance and number of species of soil macrofauna of the agricultural fields were measured. Fifteen agricultural fields were sampled. Fourteen fields were orchards of apple, apricot or the mixture of apple and apricot trees and one field was a cropland, cultivated with wheat as a monocrop. The orchards were under conservation agricultural practices; whereas, the cropland was under conventional management. These agricultural lands were 2–26 years old. The concentration of soil organic matter (SOM) in the upper 0–10 cm depth of these field sites ranged from 11.6 g kg−1 to 32.8 g kg−1 soil. As compared to cropland, orchards had significantly higher concentration of SOM and SOC. A total of 18 soil macrofauna species were found and the most common and abundant were ants (Monomorium minimum, Camponotus pennsylvanicus, Solenopsis invicta, and Lasius niger) followed by Arion ssp. (Brown Slug) and earthworm Lumbricus terrestris. Regression analysis revealed non-significant relationship of the age and the concentration of SOM with the number of macrofauna species and with the concentrations of total mineral nitrogen, bioavailable phosphorus and clay. The existence of ants had no relationship with the concentration of SOM; whereas, existence of Lumbricus terrestris tended to had a positive relationship with the concentration of SOM. The field of tree-based intercropping system was 2 years of age since the land was converted from rangeland to a cropland, had two ant species coexisting. This indicates the positive influence of crop diversification on soil macrofauna. [ABSTRACT FROM AUTHOR]

The present study was conducted to investigate earthworm diversity in the Kumaun region of Uttarakhand, India. Earthworm sampling was made from 1,409-2,224 m from the foothills of the Kumaun Himalaya to higher altitudes monthly from April 2019 to April 2021, covering the major monsoon season in India. Earthworms were collected from twelve different sites using the hand sorting method and preserved in 10% formalin. We recorded 14 earthworm species representing four families: Megascolecidae (Amynthas corticis, Amynthas morrisi, Amynthas alexandri, Metaphire anomala, Metaphire houlleti, Metaphire birmanica, & Perionyx excavatus); Lumbricidae (Aporrectodea caliginosa trapezoides, Aporrectodea rosea rosea, Eisenia fetida, Octolasion tyrtaeum, & Dendrodrilus rubidus); Moniligastridae (Drawida japonica); and Octochaetidae (Eutyphoeus nainianus). Drawida japonica from the family Moniligastridae is being reported for the first time from the Kumaun Himalaya. Moniligastrids are an important, yet often ignored, earthworm group commonly found in cultivated soils of higher altitudes. [ABSTRACT FROM AUTHOR]

Bioturbation is a key ecosystem function with a fundamental role in mediating major biogeochemical cycles. The intensity and depth of bioturbation is influenced by the taxa present, which is often a function of food supply. The deep sea is generally oligotrophic with sediments composed predominantly of small, shallow burrowing macrofauna (<10 cm). Human activity is increasingly introducing POC to the deep-sea, however, organic enrichment of the deep-sea, and the subsequent response of bioturbators is poorly understood. Here we present data on benthic function in deep-sea systems that have experienced organic enrichment. We show that organic enrichment enhances deep-sea bioturbation through larger, advanced successional taxa, and deeper bioturbation depths. Enhanced bioturbation in the deep-sea should confer positive ecosystem functions (nutrient recycling, microbiological activity, remineralization), but adherence to approaches and interpretations guided by the paradigm of small, shallow-burrowing infauna could significantly underestimate deep-sea benthic processes at a global scale. [ABSTRACT FROM AUTHOR]

Until recently, the Kara Sea was a stable ecosystem unaffected by alien species invasions. However, at the beginning of the twenty-first century, the snow crab (Chionoecetes opilio) was detected. Studies conducted between 2013 and 2022 in Blagopoluchiya Bay (Novaya Zemlya Archipelago, Kara Sea) provided an opportunity to observe the establishment of a population of this species and its influence on benthic communities. Various sampling methods, such as trawl and grab surveys, as well as video observations, were used to study two main seabed habitats, one in the deep inner basin and the other at the sill at the bay's exit. The study revealed significant changes in benthic ecosystems, including declines in integral benthic characteristics such as abundance, biomass, diversity, and shifts in dominant species. The response of megabenthos and macrobenthos varied between habitats, but in general, there was a sharp decline in the abundance of large bivalves and brittle stars. The observed changes were not related to environmental variability but most likely to the abundance and size structure of the snow crab. The taxonomic and size structure of the benthos changed as crab individuals increased in size, and the changes were faster and more pronounced in the area with higher crab abundance. These findings raise concerns about the potential long-term effects of the snow crab invasion on the Kara Sea ecosystem, including reduced biodiversity and changes in food webs. [ABSTRACT FROM AUTHOR]

The integrated assessment of ecological quality in estuarine ecosystems holds significant importance for environmental management. Previous monitoring programs predominantly focused on environmental data, lacking a comprehensive quality assessment approach. To address this gap, this study aimed to integrate environmental factors with macrofaunal community information to evaluate the ecological quality status of the Yellow River Estuary. A total of 13 stations were routinely monitored in August for four consecutive years to collect environmental and biological data. Candidate indicators were screened based on variation coefficients, distribution ranges, and redundancy analysis, identifying 16 indicators belonging to three categories (i.e., seawater, sediment, and biology). The model fit and the interrelationship of the components were determined using structural equation modelling (SEM). The main results were as follows. (1) A total of 144 macrofaunal taxa, belonging to eight animal phyla and 98 families, were identified, with a dominance of Annelida (37.8%) and Mollusca (33.3%). The environmental variables most strongly correlated with the macrofaunal community were TOC, DO, Cd, and Md. (2) NO2 and heavy metals represented the two most direct factors of environmental pollution, while the factor load of biodiversity indices (H', J, and D) was large in the biology category. (3) The evaluation results indicated that 78.85% of the total samples were between the average and upper levels of ecological quality, but only 7.69% of samples were at the "high" level. The framework system for the evaluation of ecological quality constructed in this study provides a theoretical and practical basis for the evaluation of the effectiveness of conservation management of the Yellow River Estuary. [ABSTRACT FROM AUTHOR]

Cryptofaunal nematodes, those living on the hard substrate of the coral reefs, are largely unknown in terms of diversity and assemblage structure. We described nematode assemblages at seven sites spanning about 200 km along Jardines de La Reina, a well-preserved reef system in the Greater Antilles. We identified about 3000 nematodes, mostly of the families Desmodoridae and Chromadoridae; the most abundant species were Croconema cinctum, Desmodora communis, and Euchromadora vulgaris. The regional richness was moderate with 70 observed species (0.95 confidence interval: 65–75 species) and 75 extrapolated species (0.95 CI: 68–83 species). This richness was lower than in other reef biotopes, maybe reflecting evolutionary constraints due to interactions with stony corals. The local expected richness at 100 individuals was similar among sites, with a median of 26 species (0.95 CI: 20–34 species), and likely caused by diversification rate and evolutionary time acting at the same pace on populations. The taxonomic β-diversity was high and without differences among sites (median: 0.85; 0.95 CI: 0.33–1), probably due to significant substrate heterogeneity at 10-cm scale. The prevalence of replacement over richness difference suggests that local processes (e.g., environmental filtering and competition) contribute more to β-diversity than niche availability, which would be largely similar across the reef terraces. Contrary to our expectations, no gradient of assemblage structure occurred, nor significant effect of benthic cover on nematodes. However, nematode functional structure showed a conservative set of biological traits reflecting adaptations to hydrodynamic regime: armed oral cavity/intermediate colonizing capability/ornamented cuticles/conical tail. Our results provide insights about the taxonomic and functional diversity of nematodes and highlight the vast knowledge gaps about the processes ruling the meiofauna community structure in coral reefs. [ABSTRACT FROM AUTHOR]

Increasing habitat modification and species loss demand consistent efforts to describe and understand biodiversity patterns. The BIOTA/FAPESP Program was created in this context and it has been a successful initiative to promote studies on biodiversity and conservation in Brazil. The BIOTA/Araçá is an interdisciplinary project that provided a detailed evaluation of the biodiversity of Araçá Bay, a coastal seascape located on the North coast of the state of São Paulo, Southeast Brazil. The bay encompasses multiple habitats, such as beaches, mangroves, rocky shores, and a tidal flat, and provides important ecosystem services. Unfortunately, the bay is the subject of complex social-environmental conflicts that oppose economic, social, and environmental demands (i.e., the expansion of neighboring harbor activities vs. small-scale artisanal fisheries and protection of biodiversity). The present study presents a survey of the benthic species occurring in the different habitats of Araçá Bay, including data obtained during the BIOTA/Araçá project and previous assessments of the area. The benthic species play an important role in marine environments and studying the diversity of these organisms that live associated with the bottom is indispensable for comprehending the environment's functioning. The macrofauna, meiofauna, and microorganisms associated with soft and hard bottom were listed, and additional information, such as the habitat and geographical distribution, were provided for each species. The checklist includes 826 species, almost 70% recorded during the BIOTA/Araçá project. The most speciose taxa were the annelids (225 spp.), mollusks (194 spp.), and crustaceans (177 spp.). Seven benthic species are endemic to Araçá Bay, 14 are considered threatened, and seven are economically exploited. Furthermore, the bay is the type locality of many taxa, and 11 new benthic species were described based on specimens sampled during the project. This project shows the importance of Araçá Bay as a unique biologically rich environment and highlights the need for conservation efforts in light of the current threats. [ABSTRACT FROM AUTHOR]

The macrofauna in soft sediments of the deep seafloor is generally diverse and represents a comparatively well-studied faunal group of deep-sea ecosystems. In the abyss of the Clarion Clipperton Fracture Zone (CCFZ) in the NE Pacific, macrofauna are major contributors to benthic biodiversity. Their distribution, composition, and diversity have been frequently investigated to assess the potential impacts of future mining activities on the resident fauna. In this study, patterns of densities and community structure of CCFZ macrobenthic infauna and their relationships with a range of environmental and climatic variables were examined, with a special focus on communities from the eastern German contract area (referred to as BGR CA). However, comparisons were also made with other contractor areas (e.g., IFREMER, IOM, GSR) and one Area of Particular Environmental Interest (APEI3). Material for this study was obtained by means of a box corer during six expeditions to the CCFZ between 2013 and 2018 resulting in 148 samples. Our study uncovered notable spatial and temporal variations in both faunal densities and community composition. While areas within the BGR CA exhibited a similar community composition, slight differences were observed between the various CAs and APEI3. Surprisingly, we found an unexpected negative correlation between food availability and both macrofaunal density and community structure that may be attributed to differences in sampling methodologies and pronounced temporal variation. Furthermore, we explored the impact of climatic fluctuations associated with the El Niño/Southern Oscillation (ENSO) on macrofaunal densities, observing an increase during warm (El Niño) events. Our findings underscore the challenges of accurately assessing spatial and temporal variations in the absence of standardised sampling protocols. Hence, we emphasize the importance of adopting standardised protocols to enhance data comparability, thereby fostering a deeper understanding of the underlying factors influencing spatial and temporal changes in macrofauna community structure within the CCFZ. [ABSTRACT FROM AUTHOR]

Although knowledge of Arctic benthic biodiversity has increased considerably in recent decades, some regions, such as Northeast Greenland, remain poorly studied. The aim of this study was to complement a previous macrofaunal inventory carried out in Young Sound, a High-Arctic fjord in this region (74°N). We sampled shallow benthic assemblages along a small inner/outer fjord gradient, including one station previously prospected two decades ago and three new stations. This sampling strategy revealed highly diversified benthic assemblages (166 species identified on a total sampling area of 1.32 m2), which considerably increases the number of species recorded for the fjord (i.e. 225 species vs 100 previously recorded). The outermost station was dominated in abundance by various assemblages of bivalves, while the middle stations showed greater species evenness, including numerous species of polychaetes, bivalves and crustaceans. The innermost station was dominated by ostracods, gammarid amphipods and tube-dwelling polychaetes. Overall, benthic assemblages varied little between the four stations and the transect as a whole exhibited characteristics typical of outer fjord habitats, reflecting the rather moderate impact of meltwater inputs in this part of the fjord. Finally, trophic plasticity and omnivory were observed in most of the recorded macrobenthic species, highlighting the adaptability of these species to low trophic availability in the ecosystem. Future biodiversity studies will need to explore the innermost and deepest areas to provide a more comprehensive inventory and understanding of the influence of environmental conditions on the structure and functioning of Young Sound benthic habitats. [ABSTRACT FROM AUTHOR]

Bioturbation is a key ecosystem function with a fundamental role in mediating major biogeochemical cycles. The intensity and depth of bioturbation is influenced by the taxa present, which is often a function of food supply. The deep sea is generally oligotrophic with sediments composed predominantly of small, shallow burrowing macrofauna (

This study evaluated the influence of Eucalyptus globulus L. plantations on the physical, chemical and biological properties of the soil in three districts: Magdalena, Tingo and San Isidro del Maino. The evaluation was carried out in six plots, three with eucalyptus and three with natural forests. In each plot with eucalyptus, 10 specimens were selected to measure their dasometric characteristics. Ten soil samples were taken at the base of each specimen to evaluate the bulk density and soil characterization, replicating the sampling in the natural forest plots. Additionally, biological sampling was carried out in each plot using the Rapid Soil Sampling Protocol, with a total of five quadrats per plot. The results showed significant differences in diameter at breast height (DBH), tree height and dry biomass among the districts evaluated. Trees in Magdalena presented the highest DBH and height, with an average biomass of 934.22 kg/tree, while those in Tingo showed the lowest values, with an average biomass of 230.00 kg/tree. Diverse flora species associated with both eucalyptus and natural forests were identified, reflecting a rich biodiversity in each district. Soils with eucalyptus in Tingo showed a predominantly clay texture, while in Magdalena and San Isidro del Maino a sandy loam texture predominated. In the natural forests, the soils in Tingo were also clayey, with more varied textures in the other districts. Bulk density was higher in forest soils in Tingo and in eucalyptus soils in San Isidro del Maino. Soils under eucalyptus had lower pH and lower electrical conductivity compared to natural forest soils. In terms of nutrients, the eucalyptus soils in Tingo and Magdalena showed higher phosphorus and potassium contents, while in San Isidro del Maino, the forest soils had higher levels. In general, eucalyptus soils showed higher levels of organic carbon, organic matter and nitrogen in Tingo and Magdalena, but lower in San Isidro del Maino. Biologically, natural forest soils exhibited a higher diversity and quantity of organisms compared to eucalyptus soils, especially in San Isidro del Maino. Detritivore indices were higher in natural forests, suggesting greater soil biodiversity. This higher diversity could be associated with better soil quality in these systems, highlighting the importance of natural forests in maintaining healthy soils.

Fossils play a crucial role in geoparks contributing to their scientific, educational and recreational aspects. The purpose of the project "Study and promotion of the palaeontological heritage of Kefalonia–Ithaca UNESCO Global Geopark" is the overall consideration of the palaeontological record of the geopark and its utilization with a holistic approach. Excavations took place in 11 new excavation sites and a total of more than 1000 specimens were recovered belonging to 13 major groups (ammonites, barnacles, belemnitida, bivalves, brachiopods, corals, fish, foraminifera, gastropods, plant leaves, rudists, scaphopods, and sea urchins). After being conserved and identified by the scientific staff, the specimens, along with replicas, were exhibited in two newly developed exhibitions at the Information Centres. The exhibitions were inspired by science labs as spaces of exploration, research, discovery and experience. Moreover, an educational package was prepared consisting of different activities for all ages. It presents how life, landscapes, and climate have changed over time and how living things responded to those changes. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Introduction: Ecosystem engineers play a pivotal role in shaping habitats through their activities and presence. In shallow Baltic waters, seagrasses, patch-forming mussels, and infaunal clams modify soft bottom habitats, impacting benthic community structure. While the individual effects of these ecosystem engineers are well studied, interactions among co-occurring engineers are poorly understood. Methods: We conducted a mesocosm experiment to assess the independent and combined impacts of seagrass (Zostera marina), epifaunal mussels (Mytilus spp.), and infaunal clams (Macoma balthica) on invertebrate colonization in soft sediments. Results: Our findings reveal significant engineer-driven alterations in macrofaunal community structure. Combined engineer effects diverged from individual impacts, indicating potential synergies or antagonisms in sediment (re) colonization. Notably, a higher number of engineer species positively affected the diversity of settled macrofauna, with the lowest macrofaunal abundance and biomass but the highest Shannon diversity found in the presence of all three engineers. Discussion: Results suggest that seagrass, mussels, and clams influence benthos through larval settlement and sediment biogeochemistry, providing insights into the distinct roles of habitat-forming organisms in shaping the benthic communities in coastal ecosystems of the Baltic Sea. [ABSTRACT FROM AUTHOR]

This study focuses on the paleontological content of the middle Eocene (Bartonian) carbonate–siliciclastic sediments of the Capo Mortola Calcarenite Formation from Olivetta San Michele (Liguria, Italy). Along the succession, there are significant paleoecological changes triggered by the variation in neritic input as a consequence of tectonic and climatic instability. Among microfossils, nummulitids prevail, followed by orthophragmines, smaller benthic, and planktonic foraminifera, whereas mollusks and ichnofossils are the most abundant macrofossils. The sudden changes in the benthic communities due to the progressive increase in fluvial input are recorded throughout the sedimentary succession. An increase in water turbidity caused stressful conditions for autotrophic taxa, reducing their size and abundance. In contrast, filter feeders became dominant, suggesting an increase in dissolved and suspended nutrients. Ichnological analysis shows environmental fluctuations controlled by the transport of neritic material offshore, thus confirming the general deepening trend of the studied succession. In the upper part of the succession, we recorded an alternation between gravity flows and marly sediments that are interpreted as short-term alternations between low and intense precipitations. The gravity flows yield taxa such as larger benthic foraminifera (LBF), smaller benthic and planktonic foraminifera, mollusks, and corals. In turn, marls display only a few LBF and abundant smaller benthic and planktonic foraminifera. In these intervals, the increase in planktonic foraminifera also suggests a deepening of the carbonate ramp coinciding with a reduction of light that did not favor the development of LBF. These changes are probably related to the climatic dynamics that occurred in the Bartonian in the western Tethys. [ABSTRACT FROM AUTHOR]

Mangroves rehabilitated after deforestation by commercial exploitation must be monitored to confirm that key ecosystem functions are being restored. Brachyuran crabs are conspicuous mangrove macrofauna and were selected as potential indicators of ecosystem recovery. A deforested former mangrove charcoal concession area in Ranong was rehabilitated by planting Rhizophora (1994), Bruguiera and Ceriops (1995) seedlings in single-species blocks. A second area, deforested and heavily degraded by tin mining, was rehabilitated with R. mucronata in 1985. Crabs at these sites were compared with those in a mixed-species conservation forest. Timed collections were made in 1999, 2008 and 2019 to compare crab diversity and relative abundance between sites and years. Thirty-three brachyuran crab species were recorded. Fiddler crabs (Austruca triangularis, Tubuca rosea) and the signal crab, Metaplax elegans, were most abundant, followed by sesarmid crabs (15 species). Species composition differed significantly between sites but not between the four planted tree species blocks. We propose Metaplax elegans as an indicator of ecological development in low-lying/newly formed sediments; fiddler crabs as equivalent indicators in young mangrove plantations/open forest habitats; and a diverse sesarmid community to indicate ecological functioning in older plantations/dense forests. [ABSTRACT FROM AUTHOR]

Structural complexity of mangrove forests is thought to provide critical habitats for a variety of invertebrates. We studied the influence of habitat structure and sampling time on the gastropod diversity in Khuran mangrove ecosystem in the Persian Gulf. Sampling was conducted in two successive years (February and June 2018, February and June 2019) at two mangrove habitats i.e., pneumatophore zone and mudflats. The gastropod assemblages were characterized by the dominance of specific taxa and low species richness. In total, 18 taxa were identified, including 14 species occurring in the mangrove forest and 16 species in the mudflats. Assimineidae dominated the assemblages in both mangrove habitats. Four species (Mitrella blanda, Mitrella cartwrighti, Pellamora densilabrum, Pseudominolia sp.) were found only in mudflat habitats, while two species (Bakawan rotundata, Peronia verruculata) were found only in pneumatophore zones. The gastropod assemblage structure differed significantly between habitats and sampling dates. Of the environmental variables measured, distance-based linear models revealed that total organic carbon (TOC), and total nitrogen (TN) best explained the variation in gastropod assemblage structure. We suggest that conservation efforts should focus not only on preserving mangrove forests, but also upon protecting their adjacent bare mudflats as they provide habitat for various mangrove fauna. [ABSTRACT FROM AUTHOR]

Spatial changes in environmental characteristics strongly influence the structure of benthic communities on sandy beaches, where the patterns of occurrence are mainly controlled by morphodynamic characters and biological interactions. Despite being very abundant and extensive, the Amazonian sandy beaches are among the coastal environments less well known to science. On these beaches, the ghost shrimp Lepidophthalmus siriboia Felder and Rodrigues, 1993 is an important component of the intertidal macrofauna. The present study describes the small-scale distribution patterns of L. siriboia and of the macrobenthic communities in a dissipative macrotidal Amazonian sandy beach. Samples were collected in the intertidal zone of two areas: Area 1, next to a tidal channel; and Area 2, away from the tidal channel. In Area 1, with finer sediments, there was a higher burrow density of L. siriboia and higher density and species richness of macrofauna. In both areas, the burrow density of L. siriboia increased towards the sea. The faunal distribution patterns can be explained by changes in flooding and the type of substratum across the shore and alongshore. These findings add to our knowledge of tropical sandy beach ecology and reinforce the idea that tropical macrotidal beaches have a complexity of morphological features, which are drivers of macrofaunal structure. [ABSTRACT FROM AUTHOR]

Knowing patterns and processes that govern macroinvertebrate distribution in sandy beaches becomes necessary in the framework of increasing human activities. Spatial patterns in sandy beaches are affected by daily changes in physical environmental conditions and species-specific features. Here, we assess the effect of daily changes on the spatial distribution along transects perpendicular to the waterline and habitat dispersion using Callichirus corruptus as a study model. Eleven sectors (urbanized and non-urbanized) were sampled on 6 beaches in southeastern Brazil, where ecological and biological information on this species was obtained. The spatial distribution of C. corruptus differed between the sampled sectors. However, higher density of burrows was observed in the intermediate portion, indicating aggregation in this zone. The burrow spatial dispersion index presented significant positive linear relationship with the size of saturated zones and the mean size of individuals. The spatial distribution of burrows was influenced by the sampling method, adequately represented by the gradient from low to the high tide mark in the intertidal zone. There was a strong clustering when burrows were counted along perpendicular transects to the shoreline, whereas a uniform distribution when burrows were counted in parallel transects. Aggregated patterns in the distribution of C. corruptus were observed in most of sampled beaches, highlighting the preference of the species for inhabiting the intermediate portion of the intertidal zone. Furthermore, other conditions that might additionally explain the spatial dispersion of macroinvertebrates in soft sediments and the effect of human activities on natural populations of sandy beaches remain to be explored. [ABSTRACT FROM AUTHOR]

Infaunal invertebrates are affected by the overlying water and the sediment in which they live. Therefore, understanding how these environmental conditions impact infauna is critical for evaluating how they may respond to future changes in these conditions due to climate change. Here, we considered which abiotic variables, for example, salinity, sediment characteristics (i.e. mean grain size, sorting), and water column and sediment carbonate chemistry, influence infaunal invertebrate communities and juvenile bivalve abundance at intertidal sites. We used data from sites in two regions in New Brunswick, Canada with contrasting tidal regimes and oceanographic conditions, the Bay of Fundy and the Southern Gulf of St. Lawrence. We were particularly interested in bivalve recruitment due to the importance of bivalves in ecosystem services and predicted sensitivity to climate change impacts. Using data collected in 2020 and 2021, statistical modeling was done to determine which abiotic variables were potential drivers of multivariate community composition as well as species richness, total abundance, and juvenile bivalve abundance. We found that carbonate chemistry variables, both sediment and water, explained a large amount of variation (~ 7–44%) in infaunal invertebrate communities in the two regions in both our multivariate and univariate analyses. Sediment pH explained the most variation (16.9%) in the multivariate analyses for the Bay of Fundy sites. However, in the Southern Gulf of St. Lawrence, salinity explained the most variation (9.8%) in the multivariate community composition. In the univariate modeling, alkalinity, either water column or sediment, was included in all top models for all four dependent variables, suggesting the importance of this carbonate chemistry variable for bivalves and infaunal communities. Climate change is expected to have large impacts on carbonate chemistry conditions in the oceans, specifically pH, carbonate availability, and alkalinity. The influence of carbonate chemistry parameters on infaunal invertebrate communities in these regions shows the potential sensitivity these animals have to future oceanic conditions. [ABSTRACT FROM AUTHOR]

Litter decomposition by microorganisms and animals is influenced by climate and has been found to be higher in warm and wet than in cold and dry biomes. We, however, hypothesized that the macrofaunal effect on decomposition should increase with temperature and aridity since larger animals are more tolerant to aridity than smaller organisms. This hypothesis was supported by our global analysis of macrofauna exclusion studies. Macrofauna increased litter mass loss on average by 40%, twofold higher than the highest previous estimation of macrofaunal effect on decomposition. The strongest effect was found in subtropical deserts where faunal decomposition had not been considered important. Our results highlight the need to consider animal size when exploring climate dependence of faunal decomposition, and the disproportionately large role of macrofauna in regulating litter decomposition in warm drylands. This new realization is critical for understanding element cycling in the face of global warming and aridification. [ABSTRACT FROM AUTHOR]

Benthic macroinvertebrate assemblages and environmental conditions were studied in Dakhla Bay (Morocco) to (1) characterize the macroinvertebrate composition and spatial distribution, (2) provide a species inventory, and (3) to assess the key environmental variables driving the observed patterns. We identified 9,288 individuals from 67 species. The most dominant taxa were molluscs, polychaetes and crustaceans. The most abundant species were (in this order) Peringia ulvae, Bittium reticulatum, Ophelia rathkei, Mesalia mesal and Maldane sarsi, while the most frequent were (in this order) M. sarsi, Ampelisca sp., Cyathura carinata, Naineris laevigata and Chondrochelia savignyi. The spatial distribution pattern was mainly driven by sediment grain-size and Chlorophyll-a, with hydrodynamics playing also a key role. This gives rise to a structure characterized by three different station clusters, well identified in the Hierarchical Ascending Classification analysis based on abundances, which correspond to a large moderately disturbed assemblage in the centre of the bay, a more disturbed assemblage in the extremes and a transition assemblage in between. [ABSTRACT FROM AUTHOR]

Farmers in Malang cultivated rice intensively due to water availability, but yields reduced gradually. It might also reduce soil productivity and increase pest attacks. Sorghum is one of the easiest crops to be cultivated, and Leguminosae are known as pioneer cover crops. Therefore, the conversion field to organic polyculture was needed using sorghum and legumes. The research aims were to evaluate soil fauna dynamics and soil properties in the 3, 6, and 12 months after converting (mac) into an organic polyculture. Micro-climate and soil properties were recorded including air temperature (°C), day length (hours), rainfall (mm), soil water content (%), organic matter content (%), electrical conductivity (mS.m-1), pH, and bulk density (g.cm-3). Soil macrofauna was sampled using hand sorting for five plots (20 × 20 × 10 cm) in each field. Identified soil macrofauna was used to determine the density, frequency, Important Value Index (IVI), Shannon Diversity Index (H'), Evenness Index (E), Simpson Dominance Index (D), diversity t-test, and Indicator Value. The Canonical Correspondence Analysis (CCA) was used to analyze the interaction among abiotic properties and macrofauna using PAST 4.05. Results showed that the improvement of soil properties, including soil organic matter and soil macrofauna, was recorded at six mac compared to the intensive rice field, and continuously at 12 mac. The richness, diversity, and evenness of soil macrofauna taxa were higher in the converted field than in the intensive one due to organic polyculture. Moreover, we recorded a better proportion of detritivores and predators in the converted field after 12 months. Based on Indicator Value analysis, the dominant fire ants (Solenopsis sp.) in the intensive rice field might be considered as a potential indicator of unhealthy soil in the intensive rice fields. Whereas in the converted field the dominancy of these ants greatly decreased. We concluded that within six months conversion using the organic polyculture improved soil properties. [ABSTRACT FROM AUTHOR]

Nayband Bay has been greatly influenced by a variety of human disturbances over the last three decades. The present study was undertaken to assess the ecological quality status of macrobenthic communities in Nayband Bay sediments using four benthic indices namely AMBI, M-AMBI, BENTIX, and H´. The sediment samples were taken for macrobenthos extractions and determination of grain size analysis, Total Organic Matter (TOM), and Total Organic Carbon (TOC) using a Van Veen grab. A total of 47 macrobenthos taxa (genus and species) were identified among 34825 individuals in the sampling area. Polychaeta, Malacostraca, Bivalve, Gastropoda and Echiura were the most abundance taxon with 23 (48.9%), 11 (23.4%), 6 (12.7%), 5 (10.6%), and 2 (4.2%) species. The results showed that the macrobenthic communities were characterized by sensitive (EGI) or indifferent (EGII) species of AMBI ecological groups. The opportunistic species (EGIV and V) namely Capitella capitata, Cirratulus ciratus, and Scolelepis sp. were dominated at stations with high TOC. These stations were close to the beach, where the organic matter discharges and wastewater have been released from industrial outfalls. In general, the EcoQs were “good” or “acceptable”, although four indices showed some differences in the EcoQs classifications for a given site. The results of the present study indicate that the complementary use of different indices, especially sensitivity/tolerance-based indices, is recommended for the ecological status assessment of the Iranian coastal waters of the Persian Gulf. [ABSTRACT FROM AUTHOR]

A macrofauna edáfica pode ser utilizada como bioindicadora da qualidade do solo. Nesse sentido, um levantamento foi realizado no município de Rorainópolis, Roraima, com o objetivo de avaliar a influência de diferentes sistemas de cultivo na macrofauna edáfica. Foram selecionados dois sistemas: sistema de produção orgânica e sistema de produção convencional. As amostras de solo foram coletadas no mês de outubro de 2021, em monólitos de 25 × 25 cm e profundidade de 20 cm sendo 06 amostras para cada sistema de cultivo, seguindo o método Tropical Soil Biology and Fertility (TSBF) bem como o uso de armadilhas tipo Pitfall. A macrofauna edáfica nos diferentes sistemas de uso do solo foi identificada por grupos taxonômicos. Os grupos mais abundantes nos dois sistemas avaliados foram Geophilomorpha (16 indivíduos), Haplotaxida (19 indivíduos), Araneae (24 indivíduos), Juliformia (43 indivíduos), Isoptera (49 indivíduos), Coleóptera (137 indivíduos) e Hymenoptera (193 indivíduos), este último com o maior número encontrado com 193 indivíduos. A maior frequência de ocorrência e riqueza foi encontrado no sistema orgânico. O sistema de produção orgânica com uso de práticas agroecológicas apresentou maior diversidade e riqueza, em relação ao sistema convencional. A macrofauna edáfica mostrou-se sensível aos sistemas avaliados servindo como bioindicador da qualidade do solo nestes ambientes.

Madracis spp. coral patches are the main deep–sea framework builder observed on the shelf–break scarp of the Colombian Caribbean, between 107 and 230 m depth. The Marine Protected Area, Corales de Profundidad National Natural Park, was established in 2013 to protect a site of high biodiversity associated with Madracis communities. Our research summarizes the advances in knowledge of its biodiversity as the result of four expeditions and offers insights into the state of its associated fauna. Madracis colonies occur in five areas of the park but corals thrive and build coral patches in only two of the five, both in the southwest area. Our surveys have resulted in the inventory of 337 species. Mollusca (116) dominated the fauna, followed by Bryozoa (70), Cnidaria (50), Echinodermata (39), Arthropoda (14), Annelida (13), Brachiopoda (3), and Chordata (32 fishes). Store voucher specimens at the Museo de Historia Natural Marina de Colombia–Makuriwa and metadata are available online in the SiBM database.

In 2015, the failure of the Fundão dam in Mariana, Brazil released ~43 million m3 of iron mining tailings into the environment. Despite restoration initiatives in the following years, few studies—and most focused on revegetation—have evaluated the effectiveness of the restoration process in areas impacted by the disaster. We aimed to evaluate the responses of the arthropod community in areas impacted by iron mining tailings deposition from the Fundão dam that is in the restoration process. We defined sampling units in the riparian zone of the Gualaxo do Norte River, which is under restoration, and in a native not impacted riparian zone. We collected soil arthropods using pitfall traps and sampled environmental variables in the same sites. We used generalize least squares models (GLS) to test if the restored areas already presented values of arthropod diversity and functional group abundance similar to the reference area and to test which environmental variables are influencing arthropod diversity. We also tested how large the differences of arthropod community composition between the study areas and used the index of indicator species (IndVal) to verify which species could be used as an indicator of reference or restoration areas. The diversity of arthropods and the functional groups of detritivores and omnivores were higher in the native riparian zone. Understory density, soil density, organic matter content, and microbial biomass carbon were the environmental variables that significantly explained the diversity and species composition of arthropods. We show that restoration areas still have different soil arthropod diversity values and community composition when compared to reference areas. Evaluating the response of the arthropod community to the restoration process and long-term monitoring are essential to achieve a satisfactory result in this process and achieve a self-sustaining ecosystem. [ABSTRACT FROM AUTHOR]

Macrobenthic samples were collected offshore Namibia on board R/V Mirabilis during the 3rd RGNO training and the National Marine Information and Research Centre's (NatMIRC's) plankton survey from 13th May to 17th May 2016. Two transects, Cape Frio (20º S) and Walvis Bay (23º S), hosted three stations each, while the third transect, Luderitz (26º S), hosted only one station. From the results, three oxygen zones were identified, namely Microxic (<0.1 ml l-1), Dysoxic (0.1-1.0 ml l-1), and Oxic (>1.0 ml l-1). A total of 20 Macrobenthic taxa were identified; Nematoda, Polychaeta, Cumacea, and Oligochaeta were the most dominant taxa and recorded abundances in all oxygen zones. Eighteen genera of macro-Nematoda were identified; Desmolaimus and Paracomesoma dominated in all oxygen zones, Metoncholaimus recorded higher abundance in the Dysoxic stations, and no abundance in the Oxic stations, and the opposite was observed for Halanonchus and Dorylaimopsis. H' Diversity values for both the general Macrofauna and Macro- Nematoda were higher in the Oxic stations and lower in both the Dysoxic and Microxic stations, while an opposite trend was observed for Dominance values. Density values were lower in Microxic stations and higher in Dysoxic stations, while at the Oxic stations, the density values fell in between the two hypoxic zones. [ABSTRACT FROM AUTHOR]

This article discusses a study conducted in Diu, Gujarat, India, which examined the community structure of marine macrofauna in the rocky intertidal zone. The study identified 70 species of macrofauna, with the highest diversity observed in the phylum Mollusca. The text emphasizes the importance of protecting the diverse marine habitats in Diu and calls for further research on the ecology and conservation of the region's unique marine biodiversity. The article also mentions other studies conducted in the Gulf of Kutch and Gulf of Khambhat regions, highlighting the higher diversity found in the rocky intertidal zone of the Saurashtra coast. [Extracted from the article]

Taxonomic sufficiency (TS) refers to identifying taxa to a taxonomic level sufficient to detect community changes in stressed environments and may provide a cost-effective approach in routine monitoring programs. However, there is still limited information regarding the seasonal impact of applying TS and its implications for the ecological quality evaluation in the estuarine ecosystem. This study investigated the relationship between the multivariate-AZTI's Marine Biotic Index (M-AMBI) and environmental variables in three seasons (i.e., spring, summer, and autumn) in the Liaohe River Estuary. We tested the reliability of TS for simplifying the M-AMBI methodology. The results showed that family and genus level data could reproduce the spatial-temporal patterns of community structure at the species level. The M-AMBI values showed a consistent spatial distribution pattern in all sampling seasons, with a decreasing trend with the increasing distance from the estuary mouth. Both genus and family level data performed nearly as well as species level in detecting the seasonal variations of pollutants (i.e., nutrients and total organic content). The family level M-AMBI was feasible to discern stress in the Liaohe River Estuary because of the high aggregation ratios at different taxonomic levels in all sampling seasons. These findings suggest that applying taxonomic sufficiency based on the M-AMBI provides an efficient approach for evaluating ecological quality in the Liaohe River Estuary. [ABSTRACT FROM AUTHOR]

Farmers in Malang cultivated rice intensively since 2019 due to water availability but reduce yields. It might also reduce soil productivity and increase pest attacks, so the conversion field to organic polyculture was needed using sorghum and legumes. The research aims were to evaluate soil fauna dynamics and soil properties in the three, six, and 12 months after converting (mac) into organic polyculture. Soil and micro-climate factors were recorded including air temperature (°C), day length (hours), rainfall (mm), water content (%), organic matter content (%), electrical conductivity (mS.m-1), pH, and soil bulk density (g.cm-3). Soil macrofauna was sampled using hand sorting (20 x 20 x 10 cm) with five plots at each field. Identified soil macrofauna was used to determine the density, frequency, Important Value Index (IVI), Shannon-Wiener Diversity Index (H'), Evenness Index (E), Simpson Dominance Index (D), Diversity t-test, and Indicator Species. The Canonical Correspondence Analysis (CCA) was used to analyze the interaction among abiotic factors and macrofauna using PAST 4.05. Results showed that the improvement of soil properties including soil organic matter and soil macrofauna was recorded at 6 mac compared to the intensive rice field, and continuously at 12 mac. The richness, diversity, and evenness of soil macrofauna taxa were higher in the converted field than in the intensive one due to organic polyculture. Moreover, we recorded a better proportion of detritivores and predators in the converted field after 12 months. Based on Indicator Species analysis, the dominant fire ants (Solenopsis sp.) in the intensive rice field might be considered as a potential indicator of unhealthy soil in the intensive rice fields. Whereas in the converted field the dominancy of these ants greatly decreased. We concluded that within 6 months conversion using the organic polyculture improved soil properties.

IntroductionEcosystem engineers play a pivotal role in shaping habitats through their activities and presence. In shallow Baltic waters, seagrasses, patch-forming mussels, and infaunal clams modify soft bottom habitats, impacting benthic community structure. While the individual effects of these ecosystem engineers are well studied, interactions among co-occurring engineers are poorly understood. MethodsWe conducted a mesocosm experiment to assess the independent and combined impacts of seagrass (Zostera marina), epifaunal mussels (Mytilus spp.), and infaunal clams (Macoma balthica) on invertebrate colonization in soft sediments. ResultsOur findings reveal significant engineer-driven alterations in macrofaunal community structure. Combined engineer effects diverged from individual impacts, indicating potential synergies or antagonisms in sediment (re)colonization. Notably, a higher number of engineer species positively affected the diversity of settled macrofauna, with the lowest macrofaunal abundance and biomass but the highest Shannon diversity found in the presence of all three engineers. DiscussionResults suggest that seagrass, mussels, and clams influence benthos through larval settlement and sediment biogeochemistry, providing insights into the distinct roles of habitat-forming organisms in shaping the benthic communities in coastal ecosystems of the Baltic Sea.

The integrated assessment of ecological quality in estuarine ecosystems holds significant importance for environmental management. Previous monitoring programs predominantly focused on environmental data, lacking a comprehensive quality assessment approach. To address this gap, this study aimed to integrate environmental factors with macrofaunal community information to evaluate the ecological quality status of the Yellow River Estuary. A total of 13 stations were routinely monitored in August for four consecutive years to collect environmental and biological data. Candidate indicators were screened based on variation coefficients, distribution ranges, and redundancy analysis, identifying 16 indicators belonging to three categories (i.e., seawater, sediment, and biology). The model fit and the interrelationship of the components were determined using structural equation modelling (SEM). The main results were as follows. (1) A total of 144 macrofaunal taxa, belonging to eight animal phyla and 98 families, were identified, with a dominance of Annelida (37.8%) and Mollusca (33.3%). The environmental variables most strongly correlated with the macrofaunal community were TOC, DO, Cd, and Md. (2) NO2 and heavy metals represented the two most direct factors of environmental pollution, while the factor load of biodiversity indices (H’, J, and D) was large in the biology category. (3) The evaluation results indicated that 78.85% of the total samples were between the average and upper levels of ecological quality, but only 7.69% of samples were at the “high” level. The framework system for the evaluation of ecological quality constructed in this study provides a theoretical and practical basis for the evaluation of the effectiveness of conservation management of the Yellow River Estuary.

Cryptofaunal nematodes, those living on the hard substrate of the coral reefs, are largely unknown in terms of diversity and assemblage structure. We described nematode assemblages at seven sites spanning about 200 km along Jardines de La Reina, a well-preserved reef system in the Greater Antilles. We identified about 3000 nematodes, mostly of the families Desmodoridae and Chromadoridae; the most abundant species were Croconema cinctum, Desmodora communis, and Euchromadora vulgaris. The regional richness was moderate with 70 observed species (0.95 confidence interval: 65–75 species) and 75 extrapolated species (0.95 CI: 68–83 species). This richness was lower than in other reef biotopes, maybe reflecting evolutionary constraints due to interactions with stony corals. The local expected richness at 100 individuals was similar among sites, with a median of 26 species (0.95 CI: 20–34 species), and likely caused by diversification rate and evolutionary time acting at the same pace on populations. The taxonomic β-diversity was high and without differences among sites (median: 0.85; 0.95 CI: 0.33–1), probably due to significant substrate heterogeneity at 10-cm scale. The prevalence of replacement over richness difference suggests that local processes (e.g., environmental filtering and competition) contribute more to β-diversity than niche availability, which would be largely similar across the reef terraces. Contrary to our expectations, no gradient of assemblage structure occurred, nor significant effect of benthic cover on nematodes. However, nematode functional structure showed a conservative set of biological traits reflecting adaptations to hydrodynamic regime: armed oral cavity/intermediate colonizing capability/ornamented cuticles/conical tail. Our results provide insights about the taxonomic and functional diversity of nematodes and highlight the vast knowledge gaps about the processes ruling the meiofauna community structure in coral reefs.

Abstract In soft‐bottom marine ecosystems, bedform variation is induced by wind‐ and tidal‐driven hydrodynamics. The resulting megaripples, sand waves and sandbanks form a spatially and temporally heterogeneous seafloor landscape. The strong physical forces imposed by the migration of these bedforms are important determinants for the occurrence of different macrozoobenthic species. Quantifying the effect of these forces can help in differentiating natural‐ and anthropogenically induced physical stressors. However, large‐scale mapping of seabed morphology at high resolution using multibeam echosounder is challenging, costly and time‐consuming, especially in shallow seas, prohibiting wide swaths. Instead, their bathymetry is typically studied using single‐beam transects that are interpolated to bathymetric grids with a relatively coarse resolution (20 m). However, this leaves out information on smaller scale (

Silvicultural practices affect over 30 % of the global forest area and are a major driver of forest degradation. Logging is a forest management practice that is becoming increasingly widespread, since it is an important source of income for developing countries. Despite the expanding body of research on aboveground communities, little is known about the effects of logging on belowground communities. We conducted a qualitative systematic literature review to assess the current state of knowledge about the impact of logging on soil biodiversity and ecosystem functions. We addressed the effects of logging operations (e.g., clear-cutting, selective logging) on i) soil organisms (from microorganisms to soil fauna) and ii) soil functions mediated by soil biota. In general, the reviewed articles reported a negative effect of logging operations on abundance and diversity of microorganisms. Regarding soil fauna, most studies focus on insect taxa, with the impact on other soil fauna taxa remaining poorly understood. Decomposition was the most commonly studied ecosystem function. In general, the literature has reported negative effects of logging on soil functions; however, some studies found neutral or positive responses. This review highlights that logging operations have detrimental effects on a variety of different groups of organisms (e.g., microorganisms and insects) and functions (e.g., decomposition, microbial activity, bioturbation). However, on the basis of the evidence to date, low-intensity logging operations can be a beneficial practice for the conservation of soil organisms and ecosystem functions.

El estudio se realizó en el municipio de Suchiapa, Chiapas (16°36’08’’N y 93°05’53’’W) teniendo como objetivo evaluar la composición y diversidad de la macrofauna del suelo en un gradiente de diversidad, pastizal-SAF-Bosque, para determinar la influencia de la comunidad de invertebrados del suelo. Para lo anterior se realizó un muestreo general preseleccionando los sitios al azar, utilizando dos tipos de trampas, monolitos y pitfall; se hizo una colecta de muestras por cada trampa establecida para después realizar el análisis dentro del laboratorio, se utilizaron variables como, tipos de órdenes y gremios tróficos de los invertebrados del suelo para la base de datos. Del análisis realizado se observa que hay cambios en la composición y la abundancia de la macrofauna en respuesta a las prácticas realizadas dentro de esos paisajes. El análisis estadístico de los resultados muestra que los herbívoros son el grupo de mayor presencia en los diferentes paisajes, seguidos de los detritívoros; y los depredadores y nectarívoros fueron los que menos presencia tuvieron.

Soil contamination by plastic is a global problem. Most experimental studies focus on microplastics, but large fragments, such as a variety of packaging and plastic bags, make up a significant component of plastic pollution. The effects of large fragments of household plastic debris on soil invertebrate communities are largely unexplored. The use of metabarcoding can greatly simplify the assessment of the taxonomic composition of soil invertebrates as well as their symbionts and parasites. However, the method is still underdeveloped and requires verification by classical approaches. We used metabarcoding and the traditional approach based on the morphological identification of invertebrates in assessing the effect of macroplastics on soil animal communities. Fragments of transparent or black polyethylene film measuring 40 × 40 cm were fixed on the soil surface in four forest ecosystems. After 9 months, the total abundance of mesofauna in general and individual groups of invertebrates (Collembola, Mesostigmata) was significantly reduced in the soil under the film compared to the control plots. The presence of the film did not affect the abundance of macrofauna, but in some biotopes the abundance of Isopoda, Hemiptera and Chilopoda increased and the number of Coleoptera and Diptera larvae decreased under the plastic film. The applied modification of metabarcoding revealed a significantly lower diversity of invertebrates (66 families, 105 genera) compared to the morphological method of identification (95 families, 127 genera). Wolbachia and Rickettsia, typical endosymbionts of invertebrates, but not other common parasites, were noted. In contrast to the morphological method of determination, metabarcoding revealed no significant differences in the taxonomic composition of invertebrates in the soil under the film and in the control soil. However, the significant correlation between the results of morphological identification and metabarcoding confirms the ability of metabarcoding to detect even small changes in the taxonomic composition of soil invertebrate communities.

Seagrass beds support diverse macrofaunal communities, and collectively they influence carbon and nutrient cycles; however, we know little on how seagrass disturbance alters this relationship. In Newfoundland, Canada, the invasive European green crab Carcinus maenas threatens the seagrass Zostera marina by snipping and uprooting seagrasses while foraging and burrowing. In order to understand the effects of seagrass disturbance on macrofaunal diversity and ecosystem functioning within sediments, we experimentally uprooted small patches of seagrass and compared rates of oxygen and nutrient fluxes from sediment cores from uprooted (disturbed) patches, seagrasses, and unvegetated sediments nearby. In parallel, we assessed macrofaunal biodiversity (taxonomic and functional) and sedimentary (granulometric properties and organic matter content/freshness) variables in all three of these treatments over a three‐month period. As expected, macrofaunal abundance, species richness and functional richness declined significantly initially in disturbed cores, although this decrease had little effect on benthic flux rates. Over 3 months, macrofaunal colonization of the disturbed sediments resulted in abundances similar to the natural seagrass and unvegetated treatments. We also observed a change in nutrient flux rates that we attribute to seasonal shifts in regeneration pathways rather than macrofaunal community recovery, suggesting a lesser role for macrofaunal diversity in carbon and nutrient cycling in dynamic nearshore habitats than in deeper water. Our results demonstrate the impacts of green crab‐mediated seagrass disturbance on macrofaunal abundance and community structure while highlighting their potential capacity for rapid stabilization, and emphasize the strength of large‐scale seasonal environmental changes on ecosystem processes. [ABSTRACT FROM AUTHOR]

In 2015, we studied the macrozoobenthic community composition along a dissolved oxygen gradient in the deep trough of the Gulf of St. Lawrence (Canada). We sampled the seabed at nine stations using box corers (three replicates per station), starting in the outer Gulf and ending in the Lower St. Lawrence River Estuary. We found four different communities dominated by polychaetes, crustaceans, and molluscs, with the emphasis shifting from mollusc to polychaete communities as oxygen saturation decreased. Contrary to our expectations, the stations furthest upstream in the estuary with the lowest oxygen saturation levels had the highest species diversity, and also the highest density and biomass values. Key genera of the hypoxic zone included bivalves (Thyasira), cumaceans (Diastylis), amphipods (Harpinia), and polychaetes such as Ampharete, Ceratocephale, Galathowenia, and Trochochaeta. We attribute this to the stability of the environmental conditions and the absence of stress, where the constant supply of oxygen, even at low concentrations, seems to be more important than the absolute oxygen concentration. [ABSTRACT FROM AUTHOR]

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Mangroves rehabilitated after deforestation by commercial exploitation must be monitored to confirm that key ecosystem functions are being restored. Brachyuran crabs are conspicuous mangrove macrofauna and were selected as potential indicators of ecosystem recovery. A deforested former mangrove charcoal concession area in Ranong was rehabilitated by planting Rhizophora (1994), Bruguiera and Ceriops (1995) seedlings in single-species blocks. A second area, deforested and heavily degraded by tin mining, was rehabilitated with R. mucronata in 1985. Crabs at these sites were compared with those in a mixed-species conservation forest. Timed collections were made in 1999, 2008 and 2019 to compare crab diversity and relative abundance between sites and years. Thirty-three brachyuran crab species were recorded. Fiddler crabs (Austruca triangularis, Tubuca rosea) and the signal crab, Metaplax elegans, were most abundant, followed by sesarmid crabs (15 species). Species composition differed significantly between sites but not between the four planted tree species blocks. We propose Metaplax elegans as an indicator of ecological development in low-lying/newly formed sediments; fiddler crabs as equivalent indicators in young mangrove plantations/open forest habitats; and a diverse sesarmid community to indicate ecological functioning in older plantations/dense forests.

Se describen los patrones de distribución de la macro- y meiofauna en un arrecife de coral (Punta Francés, Archipiélago Cubano, Mar Caribe). La densidad y la composición por taxa para la macrofauna y meiofauna y la diversidad de especies y de caracteres biológicos para nemátodos se compararon entre cuatro hábitats: pastos marinos, arenazo, coral muerto y fondo duro. Se detectaron consistentes patrones espaciales de distribución los cuales fueron explicados por una combinación compleja de características del hábitat. La relación señal/ruido en los datos dedistribución de la macrofauna fue lo suficientemente fuerte para detectar cambios entre hábitats pero el tamaño de los dispositivos demuestreo no fue adecuado para representar los patrones reales en el medio natural. Los patrones de distribución de la meiofauna fueron afectados por el tipo de sustrato (sedimento versus fondo duro) el cual a su vez seguramente depende del régimen hidrodinámico. Los nemátodos dominaron en los pastos marinos y los copépodos en los otros tres hábitats. La densidad de especies e individuos y la riqueza de especie de nemátodos fueron más altas en los hábitats sedimentarios debidos probablemente a mayor estabilidad física, mayor nicho espacial y más disponibilidad de alimento. La variación en la diversidad fue alta y similar entre pares de hábitats con la excepción de los hábitats en fondo duro que tuvieron menor diferenciación. La mayoría de los nemátodos que habitan sobre sustratos duros mostraron rasgos morfológicos que les permiten adaptarse al régimen hidrodinámico y a la disponibilidad de alimento (biofilm/algas), esto es cuerpo pequeño y robusto, dientes para raspar, cutícula ornamentada y capsula cefálica. Fue evidente un control físico sobre las comunidades de nemátodos pero las interacciones bióticas pueden jugar un papel más importante en pastos marinos y arenazos comparado a los hábitats de sustrato duro. La diversidad de especies de nemátodos, en términos de α- y β-diversidad fue alta a la escala del arrecife coralino en Punta Francés.