Invertebrate Survey Research Articles

Bluebills and bayou bivalves: Hurricane‐driven trophic cascades affect wintering abundance of Lesser Scaup in Louisiana

AbstractThe estuaries of coastal Louisiana overwinter a continentally significant proportion of Lesser Scaup (Aythya affinis; colloquially, “bluebills”), a migratory bird species of conservation concern since population declines began in the 1980s. Thirty‐eight years of aerial waterfowl surveys of Lake Pontchartrain—an oligohaline estuarine lagoon in southeast Louisiana—show that scaup abundance fluctuates between 0 and 1,194,907 birds, though the mechanisms driving this variation are unknown. Previous studies have shown that scaup feed primarily on mollusks, and so changes in the benthic prey community have the potential to strongly influence scaup dynamics on the Lake. Benthic communities are in turn shaped by both natural and anthropogenic disturbances (e.g., hurricanes and spillway openings), potentially creating a lagged bottom‐up trophic cascade that ultimately affects scaup abundance. Using 22 yr of paired benthic invertebrate and aerial waterfowl survey data, we found scaup populations increased with the abundance of medium‐sized Rangia clams (Rangia cuneata) and Dwarf Surf Clams (Mulinia lateralis). Those prey species declined in years when the Lake was hit by a hurricane, but medium‐sized Rangia rebounded strongly the year after, likely because storm‐surge salinity induces spawning. Using long‐term aerial survey data for scaup, we indeed found strong declines on the Lake in years when a hurricane made landfall, but scaup abundance increased the following year, presumably responding to large numbers of medium‐sized Rangia. Our three‐part analysis makes a strong case for a hurricane‐driven bottom‐up trophic cascade that affects scaup populations on Lake Pontchartrain. This study adds to a growing literature demonstrating not only that estuaries are tidally and seasonally dynamic, but that punctuated disturbance events can be important for maintaining ecosystem function.

Associations of Community Structure and Functions of Benthic Invertebrates with Nickel Concentrations: Analyses from Field Surveys.

Field surveys provide valuable empirical information about the effects of heavy metals on the biological integrity of river ecosystems. To evaluate the effect of nickel (Ni) on aquatic organisms, we conducted field surveys of benthic invertebrates and Ni concentrations at 45 sites in 19 rivers in Japan. We examined the relationships between 11 structural or functional measures of benthic invertebrate communities and free Ni ion concentrations with a 90th quantile regression model. Among the measures, Ephemeroptera, Plecoptera, and Trichoptera (EPT) richness, total wet biomass of all invertebrates, and total abundance of filter feeders were negatively associated with free Ni ion concentrations. The total abundance of mud burrowers and their percentage contribution to the abundance of all invertebrates as well as the total abundances of collector-gatherers and predators were positively associated with the Ni ion concentrations. The free ion concentrations of Ni associated with a 5% reduction of one of the 3 measures from its 90th quantile value at reference sites (EC5) were estimated to be 0.2 to 7.6 µg/L. The point estimates of EC5 were similar in order of magnitude to the environmental quality standard for Ni in the European Union. However, the usefulness of simple point estimates of effective concentrations based on quantile regression lines should be carefully examined because the uncertainties in our EC5 values were large. Environ Toxicol Chem 2019;38:1728-1737. © 2019 SETAC.

The genus Dixa (Diptera, Dixidae) in Croatian lotic habitats, with a checklist of species and relationships with the fauna of neighbouring countries.

Invertebrate surveys in Croatia conducted between 2005 and 2018 included 39 sampling sites yielding bycatch samples of Dixidae (Diptera). All records of this family from the territory of Croatia are summarized, including previously unpublished data. Collections contained six species of Dixa Meigen – D. dilatata Strobl, D. maculata Meigen, D. nebulosa Meigen, D. nubilipennis Curtis, D. puberula Loew, and D. submaculata Edwards, with Dixa dilatata reported from Croatia for the first time. Information relating to the ecoregions in which species were found and specific species traits are provided. Compared to neighbouring countries, the Croatian species assemblage is most similar to the fauna of Italy and least similar to that of Serbia and Montenegro.

Richness and taxonomic distinctness of cave invertebrates from the northeastern state of Goiás, central Brazil: a vulnerable and singular area

The karst area of the northeastern state of Goiás comprises two main municipalities: São Domingos and Posse. São Domingos is inside the limits of a Full Protection Conservation Unit known as Parque Estadual de Terra Ronca (PETeR), where a high number of caves occurs, some of them surpassing 10 km in length. Despite their protection by law, uncontrolled tourism has been threatening the integrity of the unique and fragile cave systems of São Domingos. On the other hand, the caves of Posse are much less visited, with its subterranean fauna poorly unknown and are strongly threatened by the urban areas and mining activities in the vicinity. We conducted six systematic surveys of invertebrates in 12 caves, seven of which are located in São Domingos and five in Posse, between 2010 and 2012. Immediately outside the caves, we sampled several microhabitats for comparison. We estimated richness, abundance, and taxonomic distinctness of the communities. We recorded 1,941 individuals of 344 morphospecies. Caves from São Domingos showed a higher species richness and were more taxonomic distinct than caves from Posse. Most morphospecies were considered troglophiles (188). We also found one trogloxene and one troglobite, as well as nine troglomorphic taxa that possibly are troglobitic as well. Both regions have markedly singular caves regarding its subterranean fauna, with high values of taxonomic distinctness. However, the richer caves were not necessarily the most taxonomic distinct. Conservation measures are especially necessary in the region of Posse, where caves are not legally protected and are within an area of significant urbanization. Cave entrances of Posse are near deforested vicinities, in some cases with domestic wastes and cement plants nearby.

The Genus Enlinia Aldrich in Chile (Diptera: Dolichopodidae), with the Description of Four New Species.

Four new species of Enlinia Aldrich are described from Chile: Enlinia biobio n. sp., Enlinia chilensis n. sp., Enlinia enormis n. sp., and Enlinia isoloba n. sp. These specimens were collected during a 2013 invertebrate survey in sclerophyll and Valdivian temperate rain forest habitats of the central and southern Chilean Andes. The only other species of Enlinia recorded from Chile is E. atrata (Van Duzee). Photos of holotypes and type localities and a key to the five species known to occur in Chile are provided.

Dolichopodidae of riverbeds and springs in Croatia with an updated checklist of Croatia (Diptera).

Several invertebrate surveys in Croatia conducted between 2005 and 2014 and including; e.g., Plitvice Lakes, produced 123 bycatch samples of Dolichopodidae (Diptera) from 68 sampling sites collected at 36 localities in seven counties. Seventy-seven were retrieved from emergence traps, six from pan traps and 40 were collected with sweep net and/or aspirator. They contained 420 dolichopodid flies that belonged to 64 species in 22 genera. Four species, Campsicnemus umbripennis, Hercostomus chetifer, Liancalus virens and Syntormon pallipes, accounted for over half of the yields. Contrary to most species that were found in largest numbers in rivers, and their beds in particular, S. pallipes and Hercostomus gracilis were considerably more abundant at springs. Fifty-five species could be added to the national checklist which raises the total number to 94 species. All species records are given, the habitat of each species is described, if possible, and taxonomic notes are provided for some dubious species. Finally, elements are presented to support the assumption that the extant dolichopodid species richness of Croatia is at least three- to fourfold of the current number.

First record of Ianiropsis cf. serricaudis in Maryland Coastal Bays, USA (Crustacea, Peracarida, Janiridae).

During monthly sampling of benthic invertebrates at 13 stations in the Maryland Coastal Bays (MCBs) from March to December 2012, a total of 29 individuals of Ianiropsis cf. serricaudis were collected. This species is being reported for the first time in MCBs. A detailed illustration and description of an adult male of I. cf. serricaudis from MCBs is presented. An illustrated key of males of Ianiropsis species belonging to the palpalis-group is also presented. The size of the largest male was 3.0 mm and that of the largest female was 2.5 mm. It is possible that I. cf. serricaudis was present in the MCBs, but overlooked during previous surveys of marine benthic invertebrates in the area because of its small body size and lack of taxonomic expertise.

Metabarcoding of freshwater invertebrates to detect the effects of a pesticide spill.

Biomonitoring underpins the environmental assessment of freshwater ecosystems and guides management and conservation. Current methodology for surveys of (macro)invertebrates uses coarse taxonomic identification where species-level resolution is difficult to obtain. Next-generation sequencing of entire assemblages (metabarcoding) provides a new approach for species detection, but requires further validation. We used metabarcoding of invertebrate assemblages with two fragments of the cox1 "barcode" and partial nuclear ribosomal (SSU) genes, to assess the effects of a pesticide spill in the River Kennet (southern England). Operational taxonomic unit (OTU) recovery was tested under 72 parameters (read denoising, filtering, pair merging and clustering). Similar taxonomic profiles were obtained under a broad range of parameters. The SSU marker recovered Platyhelminthes and Nematoda, missed by cox1, while Rotifera were only amplified with cox1. A reference set was created from all available barcode entries for Arthropoda in the BOLD database and clustered into OTUs. The River Kennet metabarcoding produced matches to 207 of these reference OTUs, five times the number of species recognized with morphological monitoring. The increase was due to the following: greater taxonomic resolution (e.g., splitting a single morphotaxon "Chironomidae" into 55 named OTUs); splitting of Linnaean binomials into multiple molecular OTUs; and the use of a filtration-flotation protocol for extraction of minute specimens (meiofauna). Community analyses revealed strong differences between "impacted" vs. "control" samples, detectable with each gene marker, for each major taxonomic group, and for meio- and macrofaunal samples separately. Thus, highly resolved taxonomic data can be extracted at a fraction of the time and cost of traditional nonmolecular methods, opening new avenues for freshwater invertebrate biodiversity monitoring and molecular ecology.

The Use of Biological Indices for the Assessment of the River Quality (Ruda River, Poland)

AbstractRecognition of the deteriorating conditions of rivers worldwide has called for increased efforts to improve the ecological quality of impacted river systems. This is particularly important in areas that have suffered from a significant impact of human pressure on the ecological status of water. Field studies were conducted in the Ruda River in an area that had undergone anthropogenic disturbances. The objectives of our survey were to test the biological metrics based on benthic macroinvertebrates at four study sites. Spring and autumn surveys of benthic invertebrates indicated that based on the BMWP and BMWP(PL) indices, water quality was higher in comparison with the value of Multimetric index at all of the sites that were studied. Our results revealed that the water quality was higher at the study sites that are located above the dam reservoir based on both the chemical and biological parameters. This study also indicated that both spring and autumn constitute appropriate periods for carrying out monitoring studies. The values of multimeric index indicated the same water quality (except for site 1) in both sampling periods. Anthropogenic transformations of a riverbed influence the flora and fauna and affect the ecological status of rivers.

Quantitative hydrological preferences of benthic stream invertebrates in Germany

Current knowledge regarding the flow preferences of benthic stream invertebrates is mostly based on qualitative data or expert knowledge and literature analysis. These established flow preferences are difficult to use in predictions of the effects of global change on aquatic biota. To complement the existing categories, we performed a large-scale analysis on the distribution of stream invertebrates at stream monitoring sites in order to determine their responses to various hydrological conditions.We used 325 invertebrate surveys from environmental agencies at 238 sites paired to 217 gauges across Germany covering a broad range of hydrological conditions. Based on these data, we modelled the respective probabilities of occurrences for 120 benthic invertebrate taxa within this hydrological range using hierarchical logistic regression models.Our analyses revealed that more than one-third of the taxa (18–40%) can be considered as ubiquitous and having a broad hydrological tolerance. Furthermore, 22–41% of the taxa responded to specific ranges of flow conditions with detectable optima. “Duration high flow event” represented the flow parameter that correlated best with the abundance of individual taxa, followed by “rate of change average event”, with 41 and 38% of the taxa showing a peak in their probability of occurrence at specific ranges of these metrics, respectively. The habitat suitability for these taxa may be potentially affected by global change-induced hydrological changes.Quantified hydrological traits of individual taxa might therefore support stream management and enable the prediction of taxa responses to flow alteration. The hydrological traits of stream benthic invertebrates may be used in forecasting studies in central Europe, and the methods used in this study are suitable for application in other regions with different flow regimes.

Age-related environmental gradients influence invertebrate distribution in the Prince Charles Mountains, East Antarctica.

The potential impact of environmental change on terrestrial Antarctic ecosystems can be explored by inspecting biodiversity patterns across large-scale gradients. Unfortunately, morphology-based surveys of Antarctic invertebrates are time-consuming and limited by the cryptic nature of many taxa. We used biodiversity information derived from high-throughput sequencing (HTS) to elucidate the relationship between soil properties and invertebrate biodiversity in the Prince Charles Mountains, East Antarctica. Across 136 analysed soil samples collected from Mount Menzies, Mawson Escarpment and Lake Terrasovoje, we found invertebrate distribution in the Prince Charles Mountains significantly influenced by soil salinity and/or sulfur content. Phyla Tardigrada and Arachnida occurred predominantly in low-salinity substrates with abundant nutrients, whereas Bdelloidea (Rotifera) and Chromadorea (Nematoda) were more common in highly saline substrates. A significant correlation between invertebrate occurrence, soil salinity and time since deglaciation indicates that terrain age indirectly influences Antarctic terrestrial biodiversity, with more recently deglaciated areas supporting greater diversity. Our study demonstrates the value of HTS metabarcoding to investigate environmental constraints on inconspicuous soil biodiversity across large spatial scales.

Patterns and drivers of lichen species composition in a NW-European lowland deciduous woodland complex

We surveyed lichens in an extensive area of lowland deciduous oak and beech dominated forest under wood pasture management within the New Forest National Park, southern England. This provided the basis for an investigation of factors affecting the species density and composition of epiphytic lichen communities. Fifteen 1 hectare plots were established in the same sites as a parallel invertebrate survey, of which nine were in old growth forest and six in oak plantations of between c. 150 and 300 years old. In each plot 12 trees were identified for sampling and lichens were sampled on four aspects of each trunk. Results at the plot level showed that species density was significantly higher in the old growth woodland plots from those in plantations. Plot age had a significant effect on species on oak but this was not significant for lichen communities on beech. The species density of lichens associated with Trentepohliaceae photobionts on oaks showed a linear positive relationship with increasing plot age while the species density of species with other coccal green Chlorophyta decreased with age of the plot. A major part of the lichenised fungi with Trentepohliaceae photobionts includes indicator and notable species used in conservation evaluation and this component is most affected by fragmentation and isolation of forest sites. The results emphasise the importance of long term connectivity and ecological continuity in this extensive mosaic of lowland deciduous forest.

An integrative taxonomy approach unveils unknown and threatened moth species in Amazonian rainforest fragments

Abstract This study focuses on the importance in hyperdiverse regions, such as the Amazonian forest, of accelerating and optimising the census of invertebrate communities. We carried out low‐intensity sampling of tropical moth (Lepidoptera) assemblages in disturbed forest fragments in Brazil. We combined DNA barcoding and taxonomists’ expertise to produce fast and accurate surveys of local diversity, including the recognition and census of undescribed and endemic species. Integrating expert knowledge of species distributions, we show that despite limited sampling effort, our approach revealed an unexpectedly high number of new and endemic species in severely threatened tropical forest fragments. These results highlight the risk of silent centinelan extinctions and emphasise the urgent need for accelerated invertebrate surveys in high‐endemism and human‐impacted tropical forests.

A WEIGHT-OF-EVIDENCE APPROACH TO THE ASSESSMENT OF ECOLOGICAL RISK FROM HISTORICAL CONTAMINATION OF OTTAWA RIVER SEDIMENTS NEAR CHALK RIVER LABORATORIES

Canadian Nuclear Laboratories’ Chalk River Laboratories (CRL) site is situated on the banks of the Ottawa River, about 180 km northwest of the City of Ottawa. Since 1947, the Ottawa River has received effluent from CRL’s operations. Since this time, and in particular during the operation of the national research experimental research reactor (1947–1992), radionuclides (mainly 60Co and 137Cs) and mercury released in effluents have accumulated in deep-water sediments downstream of CRL. In the following, we present a holistic summary of characterization of the historical contamination and ecological risk assessment work completed to date. The evaluation included (i) comparisons of recommended benchmark dose and screening levels with concentrations in water and sediment, (ii) determination of relevant exposure pathways and biological receptors, (iii) measured and (or) modelled contaminant exposure to benthic receptors and trophic transfer of contaminants to upper trophic level receptors, (iv) whole-sediment laboratory toxicity tests using benthic invertebrates and fish, and (v) field studies assessing possible intermediate or long-term effects on aquatic biota at the population and community levels. The ecological risk related to the contaminated sediment site was assessed using multiple lines of evidence and a weight-of-evidence approach. Despite concentrations of anthropogenic radionuclides and mercury above screening levels in Ottawa River sediments near CRL, the laboratory toxicity tests, radiological dose and mercury bioaccumulation modelling, and biological surveys of benthic invertebrates and fish indicated no significant adverse effects. Ecological risk to Ottawa River benthic invertebrates, fish, fish-eating birds and mammals from historical sediment contamination near CRL is low-to-negligible, and levels of risk will continue to decline as sediment-bound radionuclides decay and contamination is buried by new sediment.

Ecology: Ecosystem vulnerability to ocean warming.

Analysis of the temperature ranges occupied by marine species finds that the vulnerability of ecological communities to global warming may depend more on organismal physiology than on the magnitude of change. See Article p.88 The sensitivity of ecosystems to climate change depends on whether species have a preference for warmer or cooler temperatures than they currently experience or are likely to experience. This analysis of standardized surveys of shallow reef fishes and invertebrates in 81 ecoregions worldwide reveals that existing reef communities do not show a perfect fit between current temperature and the thermal niches of the species in them; marine communities are often dominated by species with warmer or cooler affinity than mean local sea temperatures. This thermal bias is a major contributor to projected local species loss, more so than spatial variation in warming rate. The data imply that locations at which the average summer sea surface temperature is around 24°C are the most vulnerable to community change in general.

RECENT BIODIVERSITY IN ANAK KRAKATAU ISLAND

<p>Anak Krakatau Island is a volcanic island in the Krakatau preservation complex. With its regular explosions, ranging from2 80 times/day in the year 2013, it was expected that the biodiversity would experience many changes. In orderto determine the recent condition of the biodiversity, especially animal inhabitants, a survey was conducted within the island in June, 2013. The survey was made for mammal, bird, reptile, and invertebrate(ground, aerial, and arboreal) diversity. For mammals, 10 live traps were used along 100 m of line transect, birds and reptiles were adopted faced encountered method, while the invertebrate survey was conducted with visual techniques with a sweep net, pit-fall traps, and light traps. The result from the inventory (especially invertebrate) was followed by determining the diversity and dominance of species. Relative abundancewas also determined for mammals only. The survey indicated that there was 1 species of mammal with 20% of relativeabundance, 13 species of birds within 11 families, 2 species of reptiles, 58 species of insect, and 10 species of non-insect invertebrates, which consisted of 6 species of Araneae, 2 species of Scorpiones, 2 species of Chilopoda. The diversity indexfor insects was 4.011 with Bothriamyrmex sp. as subdominantin which its index of 2.86, and index for non-insects was 2.079. The result also was compared with the other 3 islands of the Krakatau complex and data collected in the last 10 years.</p><p><br /><strong>Keywords</strong>: Anak Krakatau, volcanic, biodiversity</p>

Diurnal variation of fish and macrobenthic invertebrate community structure in an isolated oceanic island of the South Atlantic

The trophic structure of Ascension Island's sub-tidal reef assemblages is poorly understood. Unlike other tropical reef systems, sub-tidal habitats have very low abundance of both coral and macrophyte species. Visually dominant is a diverse assemblage of fish species, with particularly high densities ofMelichthys niger, a voracious omnivore. In contrast, the nocturnal species assemblage is notably different, visually dominated by benthic invertebrates. To quantify the difference between day and night visible assemblages, we conducted day/night pairs of transect surveys of fish and invertebrates across three depths, and spanning 9 months, assigning all species to one of 10 functional groups. Multivariate analysis of surveys revealed significant turnover in species between day and night surveys and between survey periods, with concomitant changes in species rank-abundance distributions. Juveniles of a number of fish species were determinate in observed differences. Conversely, diversity of functional groups between day/night surveys and between seasons were not different, however there was significant species turnover within functional groups between day and night assemblages. The lack of proportional change in functional groups but a turn-over of species between day and night assemblages suggest that there may be a degree of functional redundancy in Ascension Island's marine trophic profile. Further investigation into the spatio-temporal variation in trophic profile and functional diversity around the island will benefit conservation and fisheries management in this isolated and poorly understood marine system.

Synopsis of the hymenopteran fauna of Lord Howe Island with a preliminary checklist of species.

Lord Howe Island is an eroded remnant of a shield volcano approximately 600 km northeast of Sydney, New South Wales, Australia. It has fascinated biologists for more than a century because of its unique and iconic fauna and flora, and was declared a World Heritage Site in 1982. Although the terrestrial invertebrate fauna is reasonably well known for many groups, most Hymenoptera, apart from ants, have received scant attention. Here we use material collected from a recent intensive invertebrate survey, in conjunction with the published literature, to provide an overview of the Hymenoptera known from the island that can act as a basis for future taxonomic and biodiversity research. In doing so, we record 318 species from 31 hymenopteran families from the Island, and assess the proportion that are flightless and likely to be endemic to the island.

Spiders Revisited: Retracing the Steps of Herbert and Lorna Levi's Historic Invertebrate Surveys of the Jackson Hole Region of Wyoming

In 1950, Herbert and Lorna Levi collected invertebrates in Yellowstone and Grand Teton National Parks and other localities in the region. Sixty-five years later and looking towards the centennial of the National Park Service, a preliminary reassessment of the biodiversity of spiders was conducted in a subset of localities that were collected by the Levis. Specimens have been collected and are in the process of being identified. Comparison of this new collection with the historical records is currently underway. As the arts have played a crucial role in the history of national parks, we are exploring how to partner art and science to share the beauty and wonder of spiders based on our fieldwork in celebration of the upcoming National Park Service centennial.

Establishing a baseline for early detection of non-indigenous species in ports of the Canadian Arctic

The combination of global warming, resource exploitation and the resulting increase in Arctic shipping activity are expected to increase the risk of exotic species introductions to Arctic waters in the near future. Here, we provide for the first time a benthic invertebrate survey for non-indigenous species (NIS) from the Canadian Arctic coasts, incorporating historical information to identify new records. The top three ports at highest risk for introduction of NIS of the Canadian Arctic were surveyed: Churchill (Manitoba), Deception Bay (Quebec) and Iqaluit (Nunavut). A total of 236 genera and species were identified. Based on cross referencing comparisons of contemporary and historical information on species composition and distributions, 14.4% of the taxa identified can be considered new records within the port regions surveyed and 7.2% within the more extended, adjacent surrounding regions. Increased survey effort is the most likely explanation for the majority of new occurrences, however, a small number of records (n=7) were new mentions for Canada and were categorized as cryptogenic since we could not confidently describe them as being either native or introduced. Further research is required to better understand the status of these new taxa. This study provides a benchmark for early detection for benthic invertebrates in the region. Significant costs and intensive labor are involved in monitoring and in early detection surveys, but they provide a great opportunity for identifying native and introduced biodiversity, crucial to analyzing the changes taking place along one of the longest coastlines in the world, the Canadian Arctic coast.