Invertebrate Species Composition Research Articles

The impact of climate changes on the ranges of invertebrates (Diptera, Molluska) in Tavush province of Armenia

Aim. The work’s aim is to study the species composition of invertebrates (Insecta, Molluska) of the Tavush province of Armenia and changes of their ranges due to climatic conditions.Material and Methods. Our own collections of 2021–2022 from different areas of the Tavush province and the collections of invertebrates of the Scientific Centre of Zoology and Hydroecology served as study material. The collection and identification of dipterous insects and mollusks was carried out according to generally accepted methods. The work was performed at the Scientific Centre of Zoology and Hydroecology The scientific material is stored in the collection fund of the Scientific Centre.Results. As a result of our studies of invertebrate species composition, 28 species of horseflies (Tabanidae) are currently listed for the Tavush region: 27 species of phytophagous gall midges (Cecidomyiidae) and 10 species of mollusks. As a result of warming climate change new changes of locality have been registered for: 6 horsefly species S. (N.) caucasicus, Ch. (H.) f. flavipes, Ch. ludens, T. unifasciatus, T. indrae vappa, T. miki; 4 phytophagous gall midge species A. verbasci, D. tortrix, S. euphorbiae, R. terminalis; For one species of mollusk, H. buchi, there are new localities. All these species have expanded their habitat: in horseflies, changes in the range along vertical zonality are observed.Conclusions. As a result of this research, it was revealed that as a consequences of climate change, the ranges of some species of invertebrates – horseflies, gall midges‐phytophages and mollusks – have expanded compared to the data of previous years. All species in which there is a direct dependence of range change on climatic conditions can be further considered as bioindicators of climate change.

Assemblages of Trichoptera larvae on water moss in the middle reaches of the Yenisei River (Siberia, Russia).

This study provides first data on species composition of trichopterans inhabiting water moss, Fontinalis antipyretica Hedw., in the middle reaches of the Yenisei River. Analysis of Trichoptera larvae collected from samples of water moss in tail waters of the Krasnoyarsk Hydroelectric Plant in 2008-2021 revealed nine species of the order, which belonged to four families. Among them, six species belonging to the Limnephilidae family have not been mentioned in previous studies of the Yenisei invertebrates. Images of species are provided. One species, Apatania crymophyla McLachlan, was the most dense in all samples of water moss. The densities of A. crymophyla in samples of water moss in 2021 ranged within 1.2-7.0 thousand individuals / kg f.w. Other representatives of the order occurred in samples of water moss sporadically or consistently but in very low densities, which did not allow reliable quantification of their abundances. Consequently, numerous large clumps of water moss in the fast-flowing waters of the Yenisei favor an abundance of Trichoptera larvae, providing these insects refuge, food, and material for their cases. However, the reasons for the predominance of one species, A. crymophyla, are to be elucidated in further studies. The present study suggests that the contributions of Trichoptera and the total invertebrate community inhabiting water moss to biomass and energy budgets in the Yenisei have been usually underestimated before now. Hence, seasonal trends of species composition and abundance of invertebrates associated with water moss in the Yenisei River, including comparison with the entire zoobenthic community, are to be studied in the future.

Can reintroduction of beavers improve insect biodiversity?

Ecosystem engineering species, such as beavers, may help the restoration of biodiversity. Through the building of dams and lodges and altering the natural hydrology, beavers change the habitat structure and create multiple habitats that facilitate a wide variety of other organisms including terrestrial invertebrate communities. Here we study the effect of beaver reintroduction in Klosterheden in Denmark on biomass of flying invertebrates and diversity of moths. Further, aerial photos were used to assess riparian structure and productivity using the normalized difference vegetation index (NDVI). Our findings show that the presence of beavers affected flying invertebrate biomass, but that this was dependent on time of the year. Further, a strong effect of presence of beavers was found on diversity of moths. The results also show an increase in vegetation productivity and structural heterogeneity at sites with presence of beavers. Overall, our results demonstrate the importance of beavers as important ecosystem engineers that affect invertebrate species composition and abundance, as well as riparian structure and productivity.

Species Richness of Benthic Macrofauna on Rocky Outcrops in the Adriatic Sea by Using Species-Area Relationship (SAR) Tools

In the northern Adriatic Sea, rocky outcrops called “trezze” or “tegnúe” are known as biodiversity hotspots. A total of 45 rocky outcrops were studied by using non-destructive photographic sampling during SCUBA diving. Ten invertebrate phyla with 196 taxa were recorded, 86% of which were determined at species level. Among them, 65% of the taxa were sessile, primarily represented by the phyla Porifera and Chordata. The aims of the study were: to characterize the species richness and composition of epifaunal invertebrates living on rocky outcrops; to test the efficiency of using the outcrop area as a predictor of epifauna richness, using the Arrhenius Species-Area Relationship (SAR) model; and to compare the expected richness resulting from the SAR model with the richness observed from the analysis of random photo-squares. Our results show that the SAR model describes the relationship between epibenthic species richness and outcrop size well and may have important practical applications for biodiversity estimations and nature conservation implications. It provides a useful tool, also in terms of economy and speed, to estimate the species richness of the benthic epifauna of the numerous outcrops that remain unsurveyed, based on their size.

Структура зоопланктона и гидрохимическая характеристика горных водоемов Северного Тянь-Шаня

The study of hydrochemical parameters and zooplankton structure of three mountain reservoirs of the Northern Tien Shan (Lower Kolsai Lake, Tekes and Bestyubinskoe reservoirs) was carried out in August 2022. Hydrochemical analysis showed that the water in all reservoirs is fresh, soft, carbonate class, calcium group of the second type. The average content of easily oxidizing organic substances reached 5.6–7.6 mg/dm3, nitrite nitrogen – 0.011–0.044 mg/dm3, nitrate nitrogen – 0.274–0.830, ammonium nitrogen –0.045–0.091, phosphates – 0.023–0.031, iron – 0.090–0.166, silicon – 3.0–5.4, manganese - 0.011–0.025 mg/dm3. Zooplankton was represented by 41 species. Zooplankton abundance varied between 11081-69061 ex/m3. Zooplankton biomass reached 11.7–700.2 mg/m3. Cluster analysis based on the calculation of the Bray-Curtis index showed changes in the species composition of planktonic invertebrates over the past fifty years. The growth of species richness in the Lower Kolsai against the background of an increase in the quantitative indicators of planktonic invertebrates is due to the increasing recreational load on the lake and the adjacent land area. The decrease in the species richness and abundance of zooplankton in the Tekes reservoir may be due to sharp fluctuations in the water level in the seasonal and interannual aspect and its periodic filling with river water not enriched with nutrients.

Escape from troubled shores: finding of a shallow-water boreal gastropod Onoba aculeus on the high Arctic shelf

Abstract The species composition and distribution of marine invertebrates varies greatly in different bathymetric regions. Nevertheless, the process of exchange between faunas of different depths has occurred repeatedly throughout the evolution of marine biodiversity. In high latitudes, this process should occur most actively due to absence of strong temperature stratification. The presence of physiological adaptations that allow northern shallow-water organisms to live at greater depth has been demonstrated in a series of experiments. However, known cases of recent colonization by species confined to a highly productive shallow-water zone in unusually deeper Arctic habitats are almost absent. The present study describes finding of population of the gastropod Onoba aculeus (Gould, 1841) in two samples from the lower continental shelf of the Arctic Ocean. Onoba aculeus is a shallow-water amphiatlantic species widely distributed in the temperate regions. The finding reported here is at the same time, the northernmost, easternmost, and most remote from the coast location. We assume that the detection of molluscs indicates the presence of an abundant isolated population in the region.

СЫРЬЕВАЯ БАЗА ПРОМЫСЛОВЫХ БЕСПОЗВОНОЧНЫХ В АЗОВСКОМ МОРЕ И ДИНАМИКА ЕЕ ОСВОЕНИЯ В 2000–2022 ГГ.

Background. In the context of a low water conent in the Azov Sea along with an increase in its salinity and the background temperature, a decrease in the stocks of stenohaline species of bioresources and an expansion of the species composition of halotolerant species are observed; out of the latter ones, the populations of commercial invertebrates are presently characterized by a drastic increase in their stock abundance and biomass. Relevance. Upon the development of an increased salinity regime of the Azov Sea, it becomes relevant to monitor the undergoing fundamental changes in the exploitable resources of commercial invertebrates. The aim of this work has been to assess the resource potential of commercial invertebrates for the period 2000–2022 and make a forecast of its dynamics under various salinity conditions of the Azov Sea up to 2030. Methods. Analytical data characterizing the status of the exploitable resources of commercial invertebrates in the Azov Sea were originally collected during expeditionary surveys in 2000–2022. To characterize the Azov Sea stocks of commercial invertebrates, standard methods of collecting and analyzing the field samples indicative of the state of their populations have been used. Results. A retrospective analysis of the species composition of commercial invertebrates in the Azov Sea indicates an expansion of the list of commercial species, an increase in their stocks and catch volumes, as well as the potential for further additions to the list of commercial species by involving new ones, currently not targeted by fisheries. Conclusion. The development of the invertebrate fishery creates a crucial alternative to the deteriorated catches of commercial fish species and may facilitate the preservation of a small fishing fleet in the Azov Sea, preventing its decline. In the case if salinity remains in the 14.5–16.5 ‰ range or increases to 18.5 ‰, there will be maintained the favorable conditions for increasing the catches of molluscs (veined rapa whelk, mussels, unequal arc), crustaceans (shrimps, Gammarus, Artemia), insects (chironomids), and jellyfish.

From light to darkness: the duality of influence of habitat heterogeneity on Neotropical terrestrial cave invertebrate communities

ABSTRACT The theory of habitat heterogeneity, which treats one of the global drivers of biodiversity, is valid for several taxonomic groups and distinct ecosystems, including subterranean environments. However, knowledge about the factors that influence the structure of subterranean communities remains limited, especially in Neotropical regions. We sought to understand the main drivers of invertebrate species richness and composition. For that, we compared the substrate elements of twilight and deep-cave zones and their associated invertebrate communities. Variations in habitat heterogeneity were significantly related to richness in the deep cave zone, but had no effect on the fauna associated with the twilight zone. The local heterogeneity enhanced the richness in the deep cave zone due to the increase in the number of available habitats and the effect on decreasing niche overlap. For communities’ composition, the geographic distribution of caves explained the similarity between the twilight zone of different caves. Therefore, nearby caves have a more similar fauna in the entrance regions but conversely, exhibit a higher dissimilarity between communities associated with the deep-cave zone. This study highlights the influence of local habitat heterogeneity on the invertebrate communities associated with different zones of the cave.

Bathymetric trends in the body size, and diet of Astropecten americanus in the northwest Atlantic Ocean

Sea stars are major predators of marine invertebrates, in particular, mollusks. Data on the diet composition and the size structure of sea stars in the N.W. Atlantic Ocean are limited. Samples of sand star (Astropecten americanus) collected from three regions in the N.W. Atlantic Ocean were used to determine spatial and seasonal differences in diet and size structure. Samples were collected from ten stations during the 2009 spring and fall NMFS bottom trawl surveys. Four hundred and eighty-eight (488) prey items belonging to various taxa were identified from stomach contents of 524 sea stars of which 302 contained food. In terms of percentage contribution by number of prey items belonging to each taxon (Cn%), gastropods (40%), bivalves (22%) and crustaceans (21%) were the most important. Gastropods were more important in the diet of Southern New England (SNE) and Mid-Atlantic Bight (MAB) sea stars accounting for ∼50% of the diet in each area, and were consumed by 35–42% of the sea stars, whereas crustaceans were more important in Georges Bank (GB) where they contributed ∼83% of the diet, and were consumed by about 77% of the sea stars. There were more gastropods and foraminiferans in the stomachs of sea stars collected in fall, while crustaceans and bivalves were more common in spring samples. These differences may be due to spatial and seasonal differences in the abundance and composition of macrobenthic invertebrates. The size of sea stars decreased with depth, perhaps due to a reduction in prey abundance and higher sea star densities with depth. Additionally, length-weight relationships suggest that sea stars in GB were heavier at a given size (length) than those from SNE and MAB. This might have resulted from the latitudinal variation in the density and species composition of macrobenthic invertebrates that serve as prey for sea stars, such that densities were low on the continental shelf off Delaware-Virginia-North Carolina and relatively high in the region off southern Massachusetts and Rhode Island.

FRESHWATER INVERTEBRATES OF LAKE ZAISAN

In this article, freshwater invertebrates are studied. Lake Zaisan is considered as an object. The article updates the list of invertebrate fauna of Lake Zaisan, which is currently relevant. The article presents steps for collecting invertebrates and determining their species composition. According to the results of the study, the species composition of thirty-nine invertebrates was determined. The author notes that the species composition of invertebrates is higher on the coast than in the lake environment, that is, the number of planktonic invertebrates is higher than that of benthos invertebrates. The author notes that the Reed thickets and kelp areas along the Lake Shore are a favorable environment for the growth of benthos organisms, that is, the predominance of benthos invertebrates, and on the sandy shores of the lake there are no invertebrates. In the course of the study, it was found that the lake is dominated by OAR-footed Scorpions, oligochetes, chironomid larvae, ashamurt Scorpions, slug worms. High-altitude Scorpions, leeches, leeches, and water mites are rare. The article considers the problem of reducing the water level of Lake Zaisan from one hundred to five hundred meters over the past year. It is worth noting that the number of benthos organisms has also decreased, as the areas of coastal reeds and algae have dried up. In addition, it is concluded that the ichthyofauna of the lake has also decreased. The result of this research work can be applied to the standard curriculum of the discipline zoology. The information contained in the article can be used by students studying at biological faculties of higher educational institutions, biology teachers in secondary schools. It will be interesting for secondary schools near Lake zaisan to use the identified invertebrates and their photos as a local component.

RESEARCH OF KIROVSK RESERVOIR FOR DEVELOPING MOBILE ACTIVE HYDROACOUSTIC FISH PROTECTING DEVICE

The hydrological, hydrobiological and ichthyological parameters of the Kirovsk Reservoir in the West Kazakhstan region of the Republic of Kazakhstan are described. The reservoir was selected as a model for realization of the grant project No. AP09058066 “Developing mobile active hy-droacoustic fish protecting device to protect fish and juveniles from entering the dam spillways of large hydroelectric power plants and reservoirs” of the Ministry of Education and Science of the Republic of Kazakhstan. Hydrological, hydrobiological and ichthyological studies were aimed to obtain data for making optimal decisions on the design, equipment and working algorithm of the fish protection device. Hydrological studies include measuring depths and current speed in the water area of the reservoir and in front of the dam spillway. The species composition, abundance and biomass of forage invertebrates of zooplankton and zoobenthos were studied as hydrobiological indicators. The main biological indicators, fish abundance and biomass, species composition and concentration of juveniles were taken into account when studying ichthyological data. The obtained hydrological, hydrobiological and ichthyological parameters of the Kirov Reservoir served as the basis for developing the concept of a mobile active hydroacoustic fish protecting device to prevent fish and juveniles from entering the spillways of dams at the large hydroelectric power plants and reservoirs

Dietary composition of young sturgeons (Acipenseridae) from the Bulgarian section of the Danube River

ABSTRACT All sturgeon species currently living in the Danube River are either critically endangered or at the edge of extinction. Sturgeons are mainly benthic feeders, with a diet of molluscs, crustaceans, and small fishes. During the last two decades, we have seen a significant change in the species composition of benthic invertebrates in the Danube River as a result of anthropogenic impacts – hydrological and habitat modifications, introduction of alien and invasive species. The aim of this study was to investigate the food composition and the importance of different prey taxa, and to describe the feeding strategies of young sturgeons along the Bulgarian section of the Danube River. From June to August 2019, the stomach contents of 61 fish specimens from the species Acipenser stellatus, A. ruthenus, A. gueldenstaedtii were collected using gastric lavage. It was found that Obesogammarus obesus (Amphipoda) prevails in the diet of young of the year (YOY) A. stellatus and A. gueldenstaedtii, while Corbicula fluminea (Bivalvia) was the main food item of A. ruthenus. Chironomidae larvae also had high occurrences in the diet of all sturgeon species. For the YOY specimens up to 35 cm total length, nearly 94% of prey items belonged to O. obesus and diet overlap was observed. Improved knowledge about the diet of the young sturgeons could lead to the determination of the species’ major feeding habitats in the Danube River, providing crucial information for their protection and restoration.

Wet grinding of invertebrate bulk samples – a scalable and cost-efficient protocol for metabarcoding and metagenomics

DNA metabarcoding is an efficient tool to characterize invertebrate species composition in environmental samples. Most metabarcoding protocols for invertebrate bulk samples start with sample homogenization, followed by DNA extraction, amplification of a specific marker region and sequencing on a high-throughput sequencer. Many of the above-mentioned laboratory steps have been verified thoroughly and best practice strategies exist. Giving the amount of research done to validate almost all laboratory steps of metabarcoding workflows it is surprising that there is no clear recommendation for the basis of almost all metabarcoding studies: the homogenization of samples itself. For homogenization, different devices are used that can be divided into two major categories: bead mills and blenders. While bead-mills accelerate small, hard particles in a closed container or tube to break down specimens into small tissue fragments, blenders work with a rapidly rotating blades that reliably slice specimens as well as other substrate of the sample. Both methods are currently used in metabarcoding studies and have downsides to consider. Bead-mills rely on single-use plastics and therefore produce a lot of waste and are expensive. In addition to that, processing times can go up to 30 minutes making them unsuitable for large scale studies. Blenders on the other hand offer the opportunity to be cleaned and can handle larger sample volumes in shorter time, with an increased risk of cross-contamination. We here aimed to develop a fast, robust, cheap and reliable sample homogenization protocol that overcomes the above-mentioned limitations of both methods, i.e. does not produce difficult to discard waste and avoid single-use plastics while reducing overall costs. We tested the performance of the new protocol using six sorted Malaise trap insect samples and six unsorted stream macroinvertebrate kick-net samples. We used 14 technical replicates of each sample and many negative controls per sample (Fig. 1) to quantify impacts of i) insufficient homogenization and ii) possible sources of cross-contamination. Our results show that homogenization is sufficient after 3 minutes of homogenization. Rinsing the blender with water is sufficient in most cases but leads to low read-numbers in some of the negative controls. These could be further reduced by rinsing the blender with self-made drain-safe sterilization solution based on bleach but far less corrosive than pure bleach. Our results suggest that rinsing 1-2 times for 20 seconds is sufficient to avoid any cross-contamination. The improvements of the protocol in terms of speed, ease of handling, overall reduction of costs as well as the documented reliability and robustness make it an important candidate for sample homogenization after sampling in particular for large-scale and regulatory metabarcoding biodiversity assessments and monitoring programs.

Preliminary study of the benthic fauna in lakes of the Novaya Zemlya Archipelago and Vaigach Island (the Russian Arctic)

The biodiversity of freshwater fauna of the Arctic Islands of the Russian Federation is currently poorly studied and to date there are insufficient molecular genetic data concerning most of the taxa. This study presents the new data on species composition and distribution of freshwater benthic invertebrates in lakes of the Novaya Zemlya Archipelago and Vaigach Island based on both the published and the original records. A total of 29 species of invertebrates in 4 classes and 14 orders were found. Considering the published data, the list of species expands to 136 species. The copepod Mesocyclops leuckarti, the pontoporeid amphipod Monoporeia affinis, the ostracod Leucocythere mirabilis, and the mollusk Euglesa globularis were recorded for the first time from the Novaya Zemlya Archipelago. The oligochaete Rhyacodrilus coccineus, the stonefly Nemoura sahlbergi, the caddisflies Agrypnia obsoleta, Micrasema gelidum and Philarctus bergrothi were registered for the first time from Vaigach Island; P. bergrothi was also recorded for the first time from Europe. The crane fly larvae of Tipula (Arctotipula) were recorded as inhabitants of the bottom layer of Arctic lakes for the first time. The obtained molecular data are in accordance with the tabula rasa hypothesis that the invertebrate fauna of the Novaya Zemlya Archipelago and Vaigach Island are the result of recent species immigration after the Last Glacial Maximum. Our data can be used in further ecological studies and conservation management. The molecular data are of considerable interest for the taxonomy and biogeography of the fauna of the Arctic islands during the Pleistocene.

Terrestrial ecological risk analysis via dietary exposure at uranium mine sites in the Grand Canyon watershed (Arizona, USA)

The U.S. Department of the Interior recently included uranium (U) on a list of mineral commodities that are considered critical to economic and national security. The uses of U for commercial and residential energy production, defense applications, medical device technologies, and energy generation for space vehicles and satellites are known, but the environmental impacts of uranium extraction are not always well quantified. We conducted a screening-level ecological risk analysis based on exposure to mining-related elements via diets and incidental soil ingestion for terrestrial biota to provide context to chemical characterization and exposures at breccia pipe U mines in northern Arizona. Relative risks, calculated as hazard quotients (HQs), were generally low for all biological receptor models. Our models screened for risk to omnivores and insectivores (HQs>1) but not herbivores and carnivores. Uranium was not the driver of ecological risk; arsenic, cadmium, copper, and zinc were of concern for biota consuming ground-dwelling invertebrates. Invertebrate species composition should be considered when applying these models to other mining locations or future sampling at the breccia pipe mine sites. Dietary concentration thresholds (DCTs) were also calculated to understand food concentrations that may lead to ecological risk. The DCTs indicated that critical concentrations were not approached in our model scenarios, as evident in the very low HQs for most models. The DCTs may be used by natural resource and land managers as well as mine operators to screen or monitor for potential risk to terrestrial receptors as mine sites are developed and remediated in the future.

Does the buffer width matter: Testing the effectiveness of forest certificates in the protection of headwater stream ecosystems

Forest harvest has multiple impacts on adjoining freshwater ecosystems, particularly headwater streams which typically receive minimal protection against forestry. However, evidence on the effectiveness of differently sized riparian buffers remains limited. Using data from two discrete regions of Finland, we assessed the effectiveness of riparian buffers in providing protection for the riparian and stream environment, benthic invertebrate diversity and species composition, and ecosystem functioning of boreal headwater streams. Our study included streams with both wide (>15 m) and narrow (<15 m) riparian buffers, enabling comparison of the two dominant forest certificates (FSC and PEFC). Compared to unharvested reference streams, nutrient concentrations as well as stream and riparian light intensity and temperature were higher at forestry-impacted sites. The amount of woody debris, cover of aquatic mosses and particulate organic matter standing stock were strongly reduced in streams draining harvested forests, especially in narrowly buffered streams. Changes in light and nutrient conditions induced a transition towards more autotrophic conditions. Organic matter decomposition rates were elevated in forestry-impacted sites only in the southern region. Forest harvest decreased macroinvertebrate diversity and evenness, and altered community composition in the northern region, but much weaker changes were observed in the southern region. Our findings support the retention of riparian buffers, but also confirm that their effectiveness depends on the environmental context and thus remains poorly predictable. Our results also suggest that the widely applied PEFC certification does not provide sufficient protection for stream ecosystems and more stringent protocols are needed to ensure ecological sustainability of forestry.

Partial clearing of a road corridor leads to homogenisation of the invertebrate fauna

A recent plan to extend a highway in south-west Western Australia has been abandoned, but not before a 10–200m wide strip of vegetation along the alignment had been cleared. Attempts are now being made to rehabilitate the cleared area. The aim of this paper is 2-fold. First, it documents the changes in invertebrate abundance, richness and evenness in this abandoned landmark development. Second, it explores the changes in invertebrate species composition, concentrating on ants, in terms of known trends in biodiversity, with particular emphasis on biotic homogenisation. We report on the immediate changes in invertebrate assemblages from a spatial continuum of sites passing through six discrete woodland communities. A total of 69 species of ants were sampled by pitfall traps from the sites, with 50 being sampled in the 7 reference sites and 46 in the 13 cleared sites. As far as most of these simple indices are concerned, the previously cleared areas generally exhibited values that are not appreciably different from those of the reference sites, except that species richness was marginally higher in the reference sites and ant abundance was higher in the cleared area sites. There was considerable variation in numbers of ant species within Ant Niche Template categories in both the reference and cleared area sites. However, numbers of nest specialists and trophic specialists were significantly lower in cleared area sites; opportunistic species and one generalist were more abundant in cleared areas. The two-dimensional solution of the multi-dimensional scaling ordination grouped all cleared sites close together, with the reference sites and modified native vegetation site being widely scattered across the graph. The tight bunching of the cleared sites suggests that clearing for the proposed highway has resulted in homogenising the ant fauna, creating a characteristic assemblage that differed from all of the original reference sites. When considered at the ordinal level, significantly less Clitellata (worms), Malacostraca (slaters), Araneae (spiders), Blattodea (cockroaches), Dermaptera (earwigs) and Coleoptera (beetles) were sampled from the cleared sites, but significantly more Collembola (springtails), Homoptera and Heteroptera (both types of sucking bugs) were sampled in these sites. Collembola may be responding to the abundance of exotic grasses whereas the sucking bugs may have benefitted from the lush herb and shrub layer associated with the regrowth and rehabilitation efforts.

Comparison of Intertidal Invertebrate Assemblages at Four Sites around Rottnest Island, Western Australia After Seven Years of Marine Heatwaves.

A study aiming to compare the abundance and species composition of invertebrates among four sites (Strickland East, Strickland West, Strickland Far East and North Point) on intertidal rocky platforms around Rottnest Island, Western Australia was conducted in January 2018. Eight quadrats with 1m by 1m dimension were haphazardly placed at each of three zones in the sampling site including the inner, middle and outer zone in relation to the shoreline in order to obtain the data of invertebrate community structure. The result of a one-way ANOVA test with a robust covariance matrix showed that the intertidal invertebrate abundance among the four sampling sites was statistically significant different (P&lt;0.05). Then, a further test using Tukey post hoc analysis found that invertebrate abundance at Strickland East was significantly different with the assemblage of invertebrate at North Point, Strickland West and Strickland Far East at the level of significance of 1%, 5% and 10%, respectively. Whereas the cluster analysis revealed that there were two clusters of invertebrate species at Rottnest Island. In the future, it is recommended to conduct an invertebrate community structure monitoring program consistently every year covering all intertidal sites around Rottnest Island in order to obtain reliable data useful for conservation and management purposes.

Sürgü Çayı (Malatya, Türkiye)’nda Makrobentik Omurgasızların Tür Kompozisyonu ve Çeşitliliği

The study was carried out on Sürgü Stream, located in Malatya Province (Turkey), and aimed to determine the diversity and species composition of macrobenthic invertebrates. Six stations were determined on the stream and macrobenthic invertebrates were taken seasonally. As a result, 34 taxa belonging to five classes were detected; one of which belongs to Hirudinea, one of which belong to Arachnida, three to Gastropoda, five to Malacostraca and 24 to Insecta classes. Insecta was the most dominant group among the determined taxa. The Shannon Weaver Diversity Index and the Simpson Index showed that the lowest species diversity was observed at the third station while the highest species diversity was found at the second station. Also, UPGMA algorithm was used to show possible clustering relationships among the seven stations based on organisms. According to UPGMA analysis, the highest similarity value was observed between the first and second stations (87%), while the lowest similarity value was found between the second and fourth stations (13%). To date, there is no study on the determination of macrobenthic invertebrate fauna of Sürgü Stream. Therefore, all the identified taxa have been recorded for the first time for the study area.

Changes in trophic state and aquatic communities in high Arctic ponds in response to increasing goose populations

Abstract The high Arctic, including the Svalbard archipelago in the North Atlantic, has been exposed to direct and indirect drivers of climatic change such as rising temperatures and associated changes in hydrology and nutrient fluxes. In addition, the number of migrating birds, particularly geese, increased remarkably in the Svalbard archipelago during the second half of the last century. The higher number of breeding birds potentially affects water quality and the biota in ponds and lakes. We aimed to investigate the potential influence of increasing goose abundance on trophic state, taxon richness, and species composition of freshwater communities in the high Arctic. We hypothesised that higher goose abundance affects the trophic state of shallow lakes and ponds and their taxon richness and species composition. We conducted a survey of selected ponds at Svalbard along a goose abundance gradient. We used the number of area‐specific goose droppings (range of 0–94 droppings m2) as a proxy of goose presence and measured proxies for productivity as well as taxon richness and composition of phytoplankton and invertebrate communities. Presence and abundance of geese were associated with higher productivity of ponds. Invertebrate and phytoplankton taxon richness correlated (positively) with goose abundance. Both phytoplankton and invertebrate taxon richness increased with increasing nitrogen (N) concentrations. Goose abundance significantly affected phytoplankton species composition, while concentrations of total‐N and total phosphorus (P) did not. Species composition of aquatic invertebrates was most strongly affected by goose abundance, but the effect of total‐N concentration was also significant. Increased goose abundance was associated with bird driven nutrient enrichment, increased phytoplankton and invertebrate taxon richness and changes of these biological communities. Thus, in addition to climate change, the higher abundances of large migratory water fowl in many polar areas may pose a major additional stress to arctic lakes and ponds. In fact, climate change and bird impact may interact, accelerating ongoing environmental change of arctic freshwater ecosystems.