Macrofaunal Species Research Articles

The presence of insects before and after using the herbicides ammonium glufosinate and methyl metsulfurone in various doses

Abstract Biodiversity of an area is a function of local diversity or certain habitats and structures in the land area, soil biodiversity is a form of alpha diversity that plays a very important role in maintaining and improving the function of the soil to support life in it. The results of the 27 pitfall traps pitfall traps obtained as many as 311 individuals before application and 96 individuals after application trapped in pitfall traps. Of these, according to the number of individuals, macrofauna are grouped by species, consisting of 5 species and 7 families. The results of the research conducted found 11 types of soil macrofauna species, namely Diacamma holosericu, Oecophylla smaragdina, Colobopsis saundersi, Zodarion rubidum, Icius hamatus, Euborellia annulata, Monomarium pharaonis, Pardosa torrentum, Julus virgatus, Grylus bimaculatus, Anochetus rugasus. The results of the investigation after herbicide application with different doses from 27 pitfall traps obtained a total of 96 individuals caught in pitfall traps. Of these, the macrofauna were grouped by species according to the number of individuals. The introduction of species characteristics can be classified into 8 species of soil macrofauna from the study site. Consisting of 4 species and 5 families.

Macrofaunal Biodiversity and Patch Mosaics on the Deep Gulf of Mexico Seafloor

ABSTRACTThe deep‐sea benthos often exhibit exceptional biodiversity. The patch‐mosaic hypothesis proposes that this deep‐sea diversity arises from varied microhabitats with prolonged temporal persistence filtering for distinctive communities thereby increasing beta‐diversity. This study investigated environmental, community, and macrofaunal species turnover at four deep‐sea sites (~2000 m) in the northern Gulf of Mexico. Using precise small‐scale sampling with a ROV, we analyzed patterns across spatial scales from centimeters to approximately 400 km among 67 sediment cores. We examined the relationships between sedimentary carbon, sediment grain size, and macrofaunal alpha‐ and beta‐diversity. Subsequently, we explored the role of these environmental properties and their spatial arrangement in shaping communities and species distributions. We observed a consistent trend where the overall abundance and diversity of a community increased with higher carbon but decreased with increasing grain size. Substantial faunal turnover was observed among cores, even at centimeter scales, with the contribution of centimeter‐scale spatial distance rivaling that of 100‐km scales in faunal dissimilarity. Similar to alpha‐diversity, beta‐diversity exhibited strong correlations with sediment carbon and grain size. The observed random spatial structure in grain size and carbon appear to translate into randomness in both community and species distribution. These findings align with the patch‐mosaic model, underscoring the complexity of deep‐sea ecosystems. These findings suggest an intricate relationship between sedimentary attributes, faunal composition, and spatial arrangement in the deep‐sea benthos, shedding light on the mechanisms driving biodiversity in seemingly homogeneous environments.

Efficient and reliable methods for estimating the abundance of keystone coastal macrofauna over large spatial scales.

Coastal bivalves are important ecosystem engineers, and identifying critical habitats can enhance conservation outcomes for threated keystone species as well as determining hotspots for invasive species. As early action is more efficient in both conservation and mitigation of species invasions, efficient and reliable tools for mapping and monitoring species over large scales are essential. We assessed the reliability and efficiency of towed video and quadrat sampling for estimating the abundance of three keystone macrofaunal bivalve species. To assess reliability, we compared the measured density based on each of the two methods to the "true" density estimated by manually surveying an entire transect. We found that both the video and quadrat method caused underestimation of the density of bivalves, but that the amount of underestimation was comparable, and further that both methods took substantially less time than surveying an entire transect manually. The video method underestimated the abundance of Pacific oysters (Magallana gigas), European flat oysters (Ostrea edulis), and blue mussels (Mytilus spp.) by 23%, 24%, and 16%, respectively. The causes of underestimation for the two oyster species were bivalves grouped in clusters, large amounts of small individuals, and generally higher abundances. While Mytilus spp. were underestimated overall, here observer experience was important, with inexperienced observers overestimating and experienced observers underestimating. Our study found both methods to be reliable and efficient for estimating the abundance of three keystone macrofaunal species, suggesting their potential applicability to other sessile or slow-moving species. We propose that these methods, due to their efficiency, can advance scientific knowledge and enhance conservation outcomes by establishing population baselines, assessing trends over time, and identifying and protecting critical habitats.

Bioaccumulation of Cadmium and Copper in Different Areas of The Eastern Part of The Gulf of Finland

The Gulf of Finland (with the estuary of the Neva River) is located in the northeastern part of the Baltic Sea and plays a key role in the formation of biological resources and the quality of the natural environment of the entire Baltic Sea. Along with eutrophication, its ecosystem is subject to anthropogenic pollution with toxic elements, including heavy metals. In this work, we analyzed the content of cadmium and copper in bottom sediments of the Gulf of Finland and in the tissues of the dominant species of benthic macrofauna — the deposit-feeder polychaete Marenzelleria arctia and the predatory isopod Saduria entomon. Significant variability was found in the spatial distribution of these elements in both environments. The average concentrations of cadmium (0.67±0.1 mg/kg of dry matter) in bottom sediments were correspondingly two times higher, and copper (34.4±4.0 mg/ kg) 1.5 times lower than the threshold levels established for the Baltic Sea. A significantly higher content of these metals was found in the tissues of isopods than polychaetes; in some locations it is an order of magnitude higher in isopods than in polychaetes. The factor of trophic transfer of metals in the Gulf food web showed biomagnification, i. e. accumulation of metals during the transition from low-level consumers (M. arctia) to predatory consumers (S. entomon), cadmium by 3.7 times and copper by 8.7 times. Thus, both species of benthic animals have high accumulative activity in relation to cadmium and copper, which contributes to the active transport of both metals from bottom sediments to marine biota, and, ultimately, transfer to the higher levels of the food web (fish, birds and mammals).

Bioindication potentials of the grass stand and soil macrofauna for assessing the level of anthropogenic transformation of an urban park are complementary

Changes in the environment induced by anthropogenic impact or natural stressors are subject to bioindication. Most often, the anthropogenic stressors are the main object of bioindication research. Hemeroby and naturalness are considered as indicators of the level of anthropogenic transformation of ecosystems. Hemeroby is frequently used to assess disturbances in different types of vegetation. However, this concept has rarely been used to assess the impact on animals. According to the method of indicator values, species richness of a community is a marker of bioindication potential. The article compares the patterns of response of species richness of soil macrofauna and herbaceous cover communities in a city park, taking into account gradients of environmental factors, naturalness, and hemeroby. Within the study area, test plots were located. Soil macrofauna samples were taken at 105 points in each of the test sites, and soil hardness, electrical conductivity and soil temperature, litter height, and grass cover height were also measured. A geobotanical description of the vegetation cover was made within each plot. In the survey plots, 7.6 ± 3.0 plant species were found in the herbaceous layer. In soil samples, 6.8 ± 2.9 species of macrofauna were found. With an increase in the number of plant species in the herbaceous layer, the number of soil macrofauna species showed a downward trend. An increase in the number of soil macrofauna species is accompanied by a decrease in both naturalness and hemeroby of the plant community. The naturalness index does not depend on the number of plant species, but the largest number of plant species was observed under conditions of naturalness level from 0 to 1. With an increase in hemeroby, the number of plant species increases, although this relationship also has a nonlinear component. The largest number of plant species is observed at hemeroby levels from 45 to 65. Environmental factors and indicators of hemeroby and naturalness were able to explain 27% of the variation in the number of soil macrofauna species. Humidity regime and continentality did not affect the number of species. Increased variability in moisture conditions, carbonate content, and indicators of frost and cryoclimate contributed to an increase in the number of invertebrate species. Increases in acidity, mineral salts, nitrates, and soil aeration had a negative impact on the number of soil macrofauna species. Soil properties were able to explain 21% of the variation in the number of soil macrofauna species. Environmental factors and indicators of hemeroby and naturalness were able to explain 72% of the variation in the number of herbaceous plant species. Increases in moisture, acidity, mineralization, thermocline, and cryoclimate indicators had a negative impact on the number of plant species. Biological indicators can be used to assess complex environmental factors that are difficult to measure using instrumental methods. Bioindicators are also used to assess the level of anthropogenic transformation of ecosystems. The key concepts for solving this problem are the naturalness and hemeroby of plant communities, which are used as markers of ecosystem disturbance in general. Vegetation cover as a source of bioindication information can provide a biased assessment of the level of anthropogenic transformation due to its greater sensitivity to certain types of anthropogenic pressure. The potential of soil animals as a source of information on the level of anthropogenic transformation in the urban environment is quite significant. Species richness is a marker of the potential ability of a plant or animal community to provide reliable bioindication information. The bioindication complementarity of animal and plant communities is that the highest species richness of soil macrofauna is observed at a relatively low level of species richness of plant communities. Therefore, soil macrofauna can complement and clarify estimates of the level of anthropogenic transformation made using plant communities or can be an independent source of information for such estimates.

DNA metabarcoding reveals high diversity of fish and macrofaunal species in diets of little auks and other Arctic seabird species in Svalbard

Climate change is a major concern for the future of marine Arctic food webs. Diet shifts of seabirds can be used as indicators of environmental changes such as species compositions of food webs. However, studies on diets are often laborious and costly, while research in vulnerable Arctic environments benefits from short visits for data collection that minimize disturbance to Arctic wildlife and the environment. DNA-metabarcoding techniques are rapidly developing and could be used as an effective method of monitoring diet choice of seabirds. We tested DNA-metabarcoding on seabird faeces collected during short visits of typically around 30 min at breeding colonies of black-legged kittiwake Rissa tridactyla (3 colonies), Brünnich’s guillemot Uria lomvia (2 colonies) and little auk Alle alle (3 colonies). DNA metabarcoding based on COI and 18S of a limited number of faeces samples revealed a wide spectrum of fish species and crustaceans in the diets of these species, comparable with or even exceeding diversity in diet composition found in conventional, more invasive techniques where birds are shot or caught and handled to obtain samples. While previous studies on diet choice of little auk, a crustacean specialist, mainly report small fractions of unidentified fish remains, DNA metabarcoding of faeces revealed a large variety of pelagic and benthic fish species supplementing its diet. We conclude that DNA metabarcoding of seabird faeces can be an effective attribute to diet studies supporting our understanding of changes in numbers and distribution of Arctic seabirds and their marine environment.

Implications of Climate-Induced Localised Extinction of Bull Kelp (Durvillaea amatheiae) for Holdfast Macrofauna

Globally, work is being undertaken to preserve biodiversity and prevent further species extinctions. Yet, without adequate data about the presence of species within ecosystems, hidden extinctions can occur without our knowledge. Given that poleward range retractions are projected for bull kelp (Durvillaea amatheiae) in southeastern Australia, there is the potential for hidden extinctions to occur in associated macrofaunal species. However, this risk cannot be assessed due to the limited data on the invertebrate macrofauna associated with D. amatheiae. We documented macrofauna within D. amatheiae holdfasts, with the objective of establishing a first analysis of the holdfast fauna for this kelp and identifying, where possible, any host-specific taxa. Holdfasts were collected at six locations, spanning most of the range of D. amatheiae on the southeastern Australian mainland. Macrofauna were removed from holdfasts and identified to the lowest possible taxonomic level. Modelling was applied to determine factors correlated with patterns of assemblages among locations. Holdfast assemblages were found to vary significantly among locations and exhibited a latitudinal gradient in assemblage structure. The northernmost location (Aragunnu), which has the highest risk of D. amatheiae range retractions, was found to have distinct species assemblages and generally higher diversity and abundance than locations further south. However, no host-specific taxa were identified in samples, indicating that there is a low risk of multiple hidden species extinctions occurring in holdfast macrofauna, due to future range retractions of D. amatheiae. Rather, most of the macrofauna taxa in D. amatheiae holdfasts were found to also occur in association with the sympatric golden kelp Ecklonia radiata, which is not expected to undergo range retractions at the latitudes where losses of D. amatheiae are projected. Overall, there is an urgent need to develop strategies to combat projected future range retractions of D. amatheiae to reduce impacts on the species that rely on D. amatheiae for habitat.

Taxon-specific ability of saprophagous soil macrofauna to reintegrate carbon from agricultural waste into soil

Saprophagous soil macroinvertebrates may potentially degrade agricultural wastes. However, it is not known, to what extent and representatives of which taxa may help reintegrating carbon from crop residues back into soil without triggering massive carbon release into the atmosphere. To tackle this problem, we conducted a three-month-long microcosm experiment with 21 different species of macrofauna (each treatment replicated four times) belonging to 13 families to test their ability to degrade wheat straw. Simultaneously CO2 release from the microcosms was measured. Five species did not survive under experimental conditions. Among the remaining 16 species, three significantly increased wheat straw decomposition with Oryctes nasicornis larvae having inflicted the highest straw mass loss (64%) in comparison with the control, where no animals were added (29%). None of the tested species increased cumulative CO2 evolution from the microcosms, while two species significantly reduced it. The reduction of carbon loss with aerobic respiration was recorded for Cetonia aurata larvae and the earthworm Dendrobaena veneta (respectively 2.5 and 2-fold in relation to the control – 53.8±4.6 mg CO2-C g−1 soil dry weight during the entire experiment). The original integrative Carbon Sequestration Index by Macrofauna (CSIM) calculated for both of the measured parameters suggests that the woodlouse Armadillidium vulgare and to a smaller extent the earthworm D. veneta appear to be the most promising organisms for industrial climate-friendly organic waste recycling in terms of survival, straw processing and simultaneous reduction of CO2 emissions from soil. Our results proved that the engagement of saprophagous macrofauna in crop residue decomposition is a viable technique of carbon reincorporation into the soil. It is accompanied with CO2 release mitigation into the atmosphere.

Efficacy and effects of three desiccation intervals on biofouling and Eastern oysters (Crassostrea virginica) at three commercial oyster farms in the Chesapeake Bay, MD

Oyster aquaculture is a growing industry both globally and nationally. Productive coastal waters support high-density containerized culture of oysters, but also sustain many other macrofaunal species which can settle on oysters and cage materials (biofouling), causing problems for oyster farms. Desiccation, or periodic air drying, of farm infrastructure and oysters has been used to control colonization and growth of biofouling organisms on oyster farms worldwide, but the minimum necessary interval of desiccation has yet to be thoroughly assessed. Given the known stresses to oysters associated with periods of emersion, an understanding of the effects of different weekly desiccation intervals is needed. This study investigated the use of desiccation in controlling biofouling and the associated impacts to oyster growth and mortality at three oyster farms within Maryland's portion of the Chesapeake Bay, including one low salinity site in an upper Chesapeake Bay tributary and two sites in the middle portion of the Chesapeake Bay. Three desiccation treatments were applied at each site: control (no desiccation), 8 consecutive hours of desiccation per week, and 24 consecutive hours of desiccation per week. Oysters were deployed between July–December 2018 and the percent valve coverage by individual biofouling species was monitored, along with worm abundance, oyster growth, and oyster mortality. Total biofouling was significantly greater on non-desiccated oysters but minimal differences in biofouling coverage were observed among oysters desiccated for 8 or 24 h weekly. Seven biofouling species were observed among the sites, and all except for a single macroalgal species (Ulva intestinalis) were controlled by the 8- and 24-h desiccation treatments. No clear treatment-derived differences in oyster growth or mortality were observed. Overall, results suggest desiccating weekly for either 8 or 24 consecutive hours may be a suitable biofouling management strategy for gross biofouling reduction on oyster farms.

Ecological patterns of intertidal macrofauna across an anthropic gradient on tropical Gulf of Mexico sandy beaches: Insights for assessment

In the context of sandy coastlines under increasing coastal development and squeeze, coupled with the ongoing loss of global diversity, it is crucial to understand the ecological patterns of benthic macrofauna, which plays a key role in the trophic and biogeochemical functional connectivity between land and sea. Here, we assessed differences in the spatiotemporal patterns of macrofauna diversity and production in exposed sandy beaches of the southwestern Gulf of Mexico across a use and modification gradient and its utility as indicators of impacts. We also estimated the sampling effort for a representative species inventory, considering three tidal zones, and longitudinal spatial scales in four beaches twice a year, and locally after an event of great tourist incidence. The traditional diversity indices could not conclusively detect the stress gradient of the macrofauna in these systems. The abundance pattern of macrofauna species in the upper intertidal zone and the greater secondary production at the lower zone of the unmodified beaches could be useful as indicators of ecological integrity in natural beaches with similar morphodynamic conditions. On the contrary, the most disturbed beach exhibited greater instability in terms of its macrofauna temporal variation in the lower zone. We verified that the ecological integrity approach comprising both natural and anthropogenic factors and multiple stressors is a useful tool showing precisely how beach-intensive use and modification induce instability and less resilience of its macrofauna, reflected in the species' distribution by tidal zones, and the secondary production patterns. We also provide the first estimate of the optimal sampling effort required to get a representative inventory of the benthic intertidal macrofauna in sandy beaches of the Western Gulf of Mexico within a gradient.

Faunal community of a new hot vent field on the Amami Rift

Abstract Deep-sea hydrothermal vents host chemosynthesis-based ecosystems inhabited chiefly by specially adapted animals that do not live anywhere else, and depth has been shown to be a major driver of species composition at vents around Japan. Though the Ryukyu region in southern Japan is home to many hot vents, only two – Minami-Ensei Knoll and Yoron Hole – have been found shallower than 1000 m. Here, we report the discovery of a new vent field on the Amami Rift northwest off Amami Ōshima at 630 m deep. A total of 29 macrofaunal species were recorded from Amami Rift, including 19 vent specialists. Comparison of species composition across the three shallow Ryukyu vents revealed only three shared species, highlighting that all three display distinct community structure. Amami Rift exhibits distinct zonation patterns and is generally more similar to Minami-Ensei than Yoron Hole, but the presence of key taxa such as the sulphide worm Paralvinella and the mussel ‘Bathymodiolus’ platifrons as well as the absence of the symbiotic squat lobster Shinkaia and the limpet Lepetodrilus exemplify its difference with Minami-Ensei. Furthermore, the non-vent specific predators seen in these two sites were completely different. Overall, the Amami Rift vent field can be considered a shallow vent with a unique set of fauna, warranting future research on the mechanisms shaping disparate macrofaunal diversity between nearby shallow vents such as Amami Rift and Minami-Ensei. The unusual geological setting of Amami Rift at the converging point of Okinawa Trough and Ryukyu Arc may influence fluid chemistry to drive such differences.

Algal cover as a driver of diversity in communities associated with mussel assemblages across eastern Pacific ecoregions

AbstractResearch on intertidal mussel assemblages and associated communities has revealed that complexity and structure are influenced by environmental heterogeneity and local‐scale factors affecting recruitment. Research in situ in eastern and western Pacific intertidal ecosystems has suggested drivers of species diversity and community structure encompassing large geographic scales, however, there are major gaps in geographic coverage. Our aim is to fill some of these gaps by analyzing macrofaunal functional group diversity and effects of environmental factors on intertidal mussel communities from three distinct marine ecoregions in the southern and northern hemispheres. We identified the effects of algal cover and environmental heterogeneity on species richness and evenness, and we modeled factors effecting mussel layer complexity from assemblages in three marine ecoregions. We analyzed macrofaunal species diversity within one of the austral ecoregions based on the width of the coastal shelf. Species richness was highest in samples from the northern hemisphere while evenness was highest in samples from the southern hemisphere. Similarity in functional group structure for all communities sampled was ≤55% (Bray–Curtis dissimilarity) and ≤35% (Chao–Jaccard dissimilarity). Wave exposure had a significant effect on shell length and complexity of mussel matrices on rocky bench platforms. The presence of algal cover had a strong effect on species richness in mussel matrices regardless of complexity, while algal canopies had no effect on species evenness. Overall, this study provides significant new insight on the community complexity of mussel beds in parts of the world which have been poorly studied in this regard.

Macroinvertebrate assessment in seagrass ecosystem in Sinacaban Municipality, Misamis Occidental, Philippines

Abstract. Mahilac HMO, Tandingan JP, Torres AG, Amparado JRR, Roa-Quiaoit HA. 2023. Macroinvertebrate assessment in seagrass ecosystem in Sinacaban Municipality, Misamis Occidental, Philippines. Biodiversitas 24: 5586-5597. Marine ecosystems such as seagrasses are economically and ecologically important in tropical coastal areas like Sinacaban municipality, southern Philippines. This study assessed the macrobenthic species and water quality (e.g., pH, salinity, temperature, Dissolved Oxygen (DO), and total suspended solids (TSS) in three seagrass areas in the municipality. The study showed the seagrass habitats with 40 macrofaunal species from the classes Gastropoda (27), Bivalvia (11), and Crustacea (2), with Clibanarius longitarsus as the most abundant species (77 individuals or 24% relative abundance). The Strombidae family holds the highest dominance within the Gastropoda class, whereas the Arcidae family is the most dominant within the Bivalvia class. However, there is no dominant family within the Crustacea class. Water quality showed pH at 7, 30 ppt salinity, and 28? within their standard limits, while DO (8 mg/L) and TSS (127 mg/L) exceeded their range. This study recorded eight economic important species and five least concern International Union for Conservation of Nature (IUCN) species. Among the three (3) sites, the seagrass area in Libertad has the highest species richness (28), Shannon’s Index (2.92), and species evenness (0.66). The Chao estimation result revealed that Libertad (37.17) and Poblacion (18.5) have lower uncertainty in their species estimates than Colupan (39.60), which has a wider range of potential species richness. The Canonical Correspondence Analysis (CCA) proved that there are species that can adapt to a certain level of environmental parameters, like Angaria delphinus, while Decatopecten radula is one of the species that does not correlate with the water parameters in the study. The findings are critical for biodiversity conservation, ecosystem management, sustainable resource use, and adaptation to changing environments in order to maintain ecological balance and the long-term health of the seagrass ecosystem.

Faunal Diversity of Pulicat Lake, Southeast Coast of India

Pulicat Lagoon, located on the South-east Coast of India, indeed plays a crucial role in supporting a diverse range of aquatic and avian species. Pulicat Lagoon is known for its rich biodiversity. As mentioned, it supports a variety of species, including crustaceans, finfish, and migratory birds. These species are not only ecologically important but also contribute to the local economy through fisheries and tourism. The present study is an attempt to compile the faunal list based on the field survey conducted during 2005- 2007 & May to Dec 2022 by Marine Biology Regional Centre, Zoological Survey of India, Chennai and from the published literature. Altogether 354 species belong to six phyla are reported so far. Among them 65 species of microfauna (phytoplankton, and zooplankton) and 289 species of macrofauna (Cnidaria, Arthropoda, Mollusca, Echinodermata, Pisces, and Birds) were reported so far. The lagoon is also important for the local fishing communities. It serves as a breeding ground for many fish species, which are essential for the livelihoods of the people living in the region. Sustainable fisheries management is vital to ensure the long-term well-being of these communities. Periodical research and monitoring of the lagoon's biodiversity and ecological health are crucial. This can help track changes, identify emerging threats, and guide conservation efforts. Pulicat Lagoon is a valuable ecosystem that supports a wide range of species and plays a vital role in the local economy. Conservation efforts should focus on maintaining the lagoon's ecological balance, preventing further degradation, and involving local communities in sustainable management practices to ensure its long-term survival. Pulicat Lagoon faces several environmental challenges, including silt deposition, habitat degradation, soil erosion, and changes in freshwater flow. These issues can disrupt the delicate balance of the ecosystem and threaten the survival of various species.

Upper Cretaceous (Coniacian-Santonian) low diversity oyster-dominated macrofaunal association in the Eastern Desert of Egypt: Taphonomy versus ecology

In contrast to the Cenomanian-Turonian, the Coniacian-Santonian macroinvertebrates of the Middle East and North Africa are rarely investigated. Previous investigations indicated the occurrence of low diversity faunal associations, which can be attributed either to ecological (primary/biogenic) or taphonomic (secondary/sedimentologic) factors. The poorly preserved macrofauna of the Hawashia Formation (north Eastern Desert, Egypt) has been quantitively analyzed resulting in the identification of fifteen macrofaunal species including five bivalve, seven gastropod, two ammonite taxa, and one echinoid taxon. The occurrence of the ammonites Metatissotia fourneli Bayle and Texanites (T.) texanus Roemer confirm the Coniacian‒Santonian age for the Hawashia Formation. Based on litho- and biofacies, this fauna likely lived in a normal oxygen tidal-influenced shallow subtidal environment under arid conditions. Taphofacies indicates a low-energy regime with low sedimentation rate. Most shells are highly damaged (encrusted, bioeroded, and fragmented) due to their long residence time in the Taphonomic Active Zone (TAZ). Few of the benthic species have a wide geographic distribution (e.g., Oscillopha dichotoma), which generally imply low sea-level. In contrast, ammonites have been precariously recorded from Africa, Europe, and Asia in addition to South America, outlines a cosmopolitan attitude.

Functional biogeography of coastal marine invertebrates along the south‐eastern Pacific coast reveals latitudinally divergent drivers of taxonomic versus functional diversity

Characterizing the spatial structure of taxonomic and functional diversity (FD) of marine organisms across regional and latitudinal scales is essential for improving our understanding of the processes driving species richness and those that may constrain or enhance the set of species traits that define the functional structure of communities. Here, we present the functional diversity of coastal invertebrate macrofaunal species along the south‐eastern Pacific from 7°N to 56°S, describe spatial variation of species traits, and examine the relationship with environmental variables. For that, we defined the functional traits and distribution ranges of 2350 marine macroinvertebrates calculated eight metrics of FD. Random forest regression was applied to identify significant relationships between FD and six environmental variables. Finally, functional β‐turnover was estimated to detect alongshore shifts in functional structure and their coincidence with biogeographical domains. Our results show, in contrast with taxonomic richness that measures of trait differences, functional space and functional specialisation increase with latitude, while functional evenness exhibits a non‐linear shape, peaking at mid latitudes. Functional redundancy decreased significantly poleward, while indicators of vulnerability increase. In contrast to taxonomic richness, FD was tightly connected to variables indicative of stress and productivity, such as dissolved oxygen and nutrients. Sea surface temperature and coastal area best explained the increased FD redundancy and richness towards the tropics. The high spatial correlation between taxonomic and functional turnover suggests environmental filters play an important role in the functional structure of the seascape. Our findings suggest that processes favouring taxonomic richness are latitudinally divergent from those favouring functional diversity. Correlations with environmental variables suggest that increased sea surface temperature and measures of stability increase redundancy, while variations in dissolved oxygen and nutrients positively affect functional diversification. Moreover, the functional diversity patterns suggest low resilience of high latitude coastal ecosystems, which are heavily exploited and threatened by climate change, hence highlighting the urgent need for effective conservation policies.

Community Structure of Marine Macrofauna at Diu coast, Gujarat, India

The marine ecosystem support variety of habitat that consequently supports high species diversity. The present study investigated the diversity of marine macrofauna in the rocky intertidal zone of Diu, Gujarat. Survey was carried out from 4 different sites during April 2022 to March 2023. During the study, all the study sites were surveyed regularly on monthly basis during the lowest low tide period. During the examination, the encountered fauna was carefully observed along the coast using a Quadrat method and visual encounter method and extensive photography was carried out. This study demonstrates 70 species of macrofauna at coastal area of Diu. The highest diversity was observed in the phylum Mollusca (37 species), followed by phylum Arthropoda (16 species), Cnidaria (8 species), Porifera (4 species), Annelida (species 2), Echinodermata (2 species), Platyhelminthes (1 species). This study highlights the importance of protecting the diverse marine habitats in Diu and emphasizes the need for further research on the ecology and conservation of the region’s unique marine biodiversity.

Decommissioning of offshore wind farms and its impact on benthic ecology

At the end of their operational life time offshore wind farms need to be decommissioned. How and to what extent the removal of the underwater structures impairs the ecosystem that developed during the operational phase of the wind farm is not known. So, decision makers face a knowledge gap, making the consideration of such ecological impacts challenging when planning decommissioning. This study evaluates how complete or partial decommissioning of foundation structure and scour protection layer impacts local epibenthic macrofauna biodiversity. We assessed three decommissioning alternatives (one for complete and two for partial removal) regarding their impact on epibenthic macrofauna species richness. The results imply that leaving the scour protection layer in situ will preserve a considerable number of species while cutting of the foundation structure above seabed will be beneficial for the fauna of such foundation structures where no scour protection is installed. These results should be taken with a grain of salt, as the current data base is rather limited. Data need to be improved substantially to allow for reliable statements and sound advice regarding the ecological impact of offshore wind farm decommissioning.

Распространение раковинных брюхоногих моллюсков с длительной и короткой пелагической стадиями в открытых районах Баренцева моря

The duration of the pelagic stage in different species of gastropod molluscs affects their ability to disperse by marine currents. We counted the number of species with long (planktotrophic larva) and short or absent (lecitotrophic larva) pelagic stages in development in shell gastropods from 8 areas of the open part of the Barents Sea. A total of 66 species were identified in the study area, of which 25 were true micromolluscs, and 41 species were represented mainly by juvenile individuals of larger molluscsby larger macrofaunal species. The predominant type of development is lecithotrophic (57 species) and partially pelagic planktotrophic (9 species). According to our data, the shares proportions of species with lecithotrophic and planktotrophic types of development are approximately the same in all investigated areas of the Barents Sea. But in the southern part of the Barents Sea the share of species with a long pelagic stage are sligthlyis slightly higher than in more numerous than in its northern part.

The Ecological Role of Ruppia cirrhosa (Petagna) Grande in a Choked Lagoon

We studied the ecological and functional aspects (such as role in sediment characteristics and plant–animal interactions) of a Ruppia cirrhosa (Petagna) Grande meadow during its vegetative season in the choked Valle Campo lagoon, a sub-basin of the wider Valli di Comacchio, on the Northern Adriatic coast. Sampling campaigns were carried out with a roughly fortnightly frequency in 2017 at two sites, one with the Ruppia meadow and one with bare sediment. Sediment parameters analyzed were microphytobenthic chlorophyll-a, protein, carbohydrate, and lipid content, and total organic matter. The macrobenthos was identified at the lowest possible taxonomic level. Chlorophyll a, as a surrogate of microphytobenthos, showed differences between the two sites, probably mainly related to light intensity; thus, it is expected that the absence of seagrass canopy results in the higher production of microphytobenthos. At both sites, proteins were the dominant class of labile compounds, suggesting that detrital organic matter present at both study sites is of high nutritional quality. The high protein/carbohydrate ratio also suggests the presence of non-aged organic matter. We recorded a total of 18 macroinvertebrate taxa. The Ruppia meadow showed a positive influence on macrofauna abundance, diversity, species richness, and composition of trophic groups. Only the infaunal taxa Capitella capitata and Chironomus salinarius exhibited higher abundance at the bare site. The ecological quality status measured by the M-AMBI index was unsatisfactory everywhere. However, the presence of the Ruppia meadow resulted in index values being consistently higher. The role of this minor seagrass has been proved to be of great importance, improving the nutritional quality of the organic matter in the sediments and, above all, providing new habitats and new niches for a number of benthic macrofauna species.