Aquatic Invertebrate Diversity Research Articles

Mine Wastewater Effect on the Aquatic Diversity and the Ecological Status of the Watercourses in Southern Poland

Coal mining activity contributes to energy security and employment occupation, but is associated with environmental deterioration. Coal combustion leads to GHG emissions, while coal mining results in the generation of saline effluents. These effluents are discharged in inland surface waters, applying significant pressure on their quality, with a negative impact on aquatic life and the economy of a region. This study includes water samples that were analyzed in order to investigate the organic compounds, heavy metals, and other physicochemical parameters. Biological monitoring was done according to the Water Framework Directive methodology. The results from an aquatic area in Southern Poland, which indirectly receives coal mine effluents, indicate elevated salinity with excessive chlorides, sulfates, and sodium ions. The water quality of another non-polluted aquatic area was also assessed to examine the impact of indirect coal mine wastewater discharge on this area. The high salinity levels hinder the use of river water for drinking, agricultural, or industrial purposes. The results obtained show high pressure on the ecological status of streams and rivers that receive mine effluents, and on the density and diversity of aquatic invertebrates. This pressure is clearly visible in the structure of benthic communities and in invertebrate diversity. It also contributes to the appearance of invasive species and increasing water salinity. Limiting discharges of mine water transporting large loads of saline substances would reduce the negative impact on the quality of river waters and biological life.

Changes in functional diversity of aquatic invertebrates across urbanization levels in a coastal island, Brazil

Changes in functional diversity of aquatic invertebrates across urbanization levels in a coastal island, Brazil

Cladocera (Crustacea; Branchiopoda) from the Brazilian Cerrado – the richness and species composition for Goiás state

Goiás state, situated in the Cerrado biome harbors several water bodies belonging to the Paraná, São Francisco, and Tocantins-Araguaia hydrographic regions. However, there are several gaps in the knowledge about the diversity and geographic distribution of aquatic invertebrates in the state, including microcrustaceans of the Superorder Cladocera. Thus, this study aims to elaborate an updated list of cladoceran species occurring in Goiás, using data from 37 literature sources and original samples from different ecosystems and localities. The history and type of publications were evaluated. The number of studies between 1988 and 2022 and the type of publications and species richness were listed. The literature data indicated that most studies reporting or describing species for Goiás were found in papers published in indexed journals (75%). Tocantins-Araguaia was the hydrographic region with the highest number of studies (20). The number of observed species was strongly related to the number of studies (r2 = 0.59; p < 0.0001). When observing literature data and findings from sampling, 92 species were recorded with five news reports: Scapholeberis freyi, Grimaldina freyi, Parvalona parva, Chydorus brevilabris, and Picripleuroxus quasidenticulatus. The number and composition of species in Goiás state should be considered relevant. However, the observed richness is lower than expected (114 spp), suggesting the need for increased sampling effort. The focus of this sampling should preferably occur in areas lacking information.

AQUATIC INVERTEBRATES ASSEMBLAGES RESPONSES TO WATERSHED LAND USE IN TABIN WILDLIFE RESERVE (TWR), LAHAD DATU, SABAH, MALAYSIA

A study on the aquatic invertebrate communities was conducted at Tabin Wildlife Reserve (TWR), Lahad Datu, Sabah, with the objectives to study (i) the diversity of aquatic invertebrates across different land use, (ii) the composition of aquatic invertebrates in different habitats and microhabitats in the stream, and (iii) the relationship between invertebrates and the water quality of the stream. Sampling was done at Sg. Lipad which flows across the secondary forest area and plantation area. Kick net method was used to sample the aquatic invertebrates for 14 continuous days in January to February 2015. A total of 3,579 individuals were sampled consisting of 76 families from eight orders, in both of the land uses. The diversity of aquatic invertebrates in the secondary forest was found to be slightly higher than plantation area with H’= 3.213 and H’= 3.188 respectively. The aquatic invertebrates were also found to be more abundant in riffle habitat, and the least in pool habitats. The diversity for pool habitat, however, was the highest among all other habitats with H’= 3.709. Both physico-chemical parameters and biotic indices indicated that the invertebrate communities were affected by the water quality in the surroundings, and may be used for rapid assessment of water quality at TWR.

Aquatic invertebrate diversity profiling in heterogeneous wetland habitats by environmental DNA metabarcoding

Invertebrates play vital roles in maintaining biodiversity and food web structure. However, it is difficult to identify invertebrate taxa across complex habitats due to the limitation of traditional morphology. In subtropical wetlands, environmental DNA (eDNA) metabarcoding was used to characterize the composition and diversity of aquatic invertebrates and analyze the environmental impacts on invertebrate community structure. According to the relative abundance (%) of invertebrate OTU richness, 30 sampling sites in wetlands were clustered into six zones, which exhibited significant spatial (i.e., wetland type-specific) differences in taxonomic composition. The relative OTU abundance (%) at the phylum level showed that Cnidaria (48.5%) > Porifera (19.4%) > Rotifera (11.0%) > Mollusca (9.2%) > Annelida (5.3 ± 2.8%) > others (less than 2.2%). Of the five alpha diversity indexes, ‘Simpson’ was the most effective index to distinguish the spatial differences in invertebrate diversity, and the class-level alpha diversity showed higher recognition than other taxonomic levels. The class-level biomarkers that could indicate the habitat-specific composition of local invertebrates were Insecta, Cnidaria, Hydrozoa, and Gastropoda in the inflow river; Ascidiacea and Demospongiae in the fluvial wetland; Clitellata, Gymnolaemata, and Monogononta in the lacustrine wetland; and Echinoidea in the estuarine wetland. The associations between environmental factors and invertebrate OTU richness based on redundancy analysis showed the taxon-level tendency of phylum (78.5%) > class (73.4%) > order (69.3%) > family (64.9%) > genus (61.2%). Our results demonstrated that aquatic invertebrate diversity profiling by environmental DNA metabarcoding can effectively reflect the composition, diversity and biomarkers of invertebrate communities. In the future, because of its great application potential, the eDNA technique may play an important role in biomonitoring complex water environments.

Aquatic invertebrate community structure and functions within a Ramsar wetland of a premier conservation area in South Africa

The Ramsar-accredited Makuleke Wetlands are located in the Makuleke Concession in the northern Pafuri region of the Kruger National Park in South Africa. The Pafuri area holds up to 75% of Kruger National Park’s total biodiversity, emphasising the Makuleke Wetlands’ international environmental importance. The Makuleke Wetlands are composed of the floodplains of the Luvuvhu and Limpopo rivers, with an estimated 31 wetlands present within the floodplains. Ten floodplain wetlands were assessed in the Makuleke region, eight of which are fed by the Limpopo River and the other two from the Luvuvhu River. Water and aquatic invertebrate communities were sampled at each site during surveys in April and September 2015 to provide baseline information on the aquatic biota of this Ramsar site. Multivariate data analytical techniques were used to assess the role of season and water quality in structuring the aquatic invertebrate communities of the wetlands. Macroinvertebrate functional feeding group ratios were also calculated as an indication of wetland ecosystem structure and function. Aquatic invertebrate diversity was some of the highest recorded for wetlands in South Africa, indicating the important role these habitats play in supporting high biodiversity in the Makuleke region. Worryingly, one of the most prolific invasive molluscan species, Tarebia granifera, was present in the wetlands and is a significant threat to native biodiversity of this conservation area. Community characteristics and ecosystem structure and function of the aquatic invertebrates further indicated that the Makuleke Wetland habitats were of good quality and provided a sufficient stable substrate for all aquatic invertebrates. Functionally, the system was characterised as reliant on heterotrophic inputs as autotrophic sources are limited. This is the first study of its kind for the region and lays the groundwork for future ecosystem studies on these important wetlands in the second-largest floodplain of South Africa.

The Role of Habitat Protection in Maintaining the Diversity of Aquatic Fauna in Rural and Industrial Areas

In Natural Landscape Complexes and Ecological Sites, local environmental protection is used to cover previous industrial activities, fragments of the cultural landscape, and habitats of both vertebrates and invertebrates. In water bodies within the different types of habitat protection, aquatic invertebrate fauna was studied to investigate whether it is a general rule that different forms of protection ensure the diversity of aquatic invertebrates in rural and industrial areas. The research revealed differences between invertebrate assemblages within complexes and between reservoirs. Compared with unprotected reservoirs located in the same area, in the majority of the studied water bodies, either no alien species were found or their relative abundance in assemblages was very low. Significant differences in the density, the number of taxa, the diversity, and the percentage of alien species were observed between different geographical locations. The location of water bodies within the protected area plays an important role in maintaining benthos diversity in industrial areas. These findings are useful for comparison with those of future research to document possible improvements or ongoing ecological regression in the quality of aquatic ecosystems in industrial areas. This study can help guide revisions of protected habitat networks for adequate protection of freshwater biodiversity in industrial areas.

Thermal regime, together with lateral connectivity, control aquatic invertebrate composition in river floodplains

Abstract Large river floodplains are dynamic environments, where alternating low and high flows are key ecological processes shaping aquatic biota. As a result of fluctuations in flow in floodplain channels, the diversity of benthic assemblages is assumed to result from the balance between surface flow connections, which are dominant during high flows, and groundwater inputs, which are dominant during low flows. However, the relative importance of these inputs in explaining aquatic invertebrate diversity has never been tested. The response of aquatic invertebrates to hydrological changes of a river floodplain was investigated in seven braided and six braided–anastomosed floodplain channels of the French upper Rhône River that are fed by three different processes: groundwater supply (which controls the thermal inertia of the water bodies), surface slow flow connections (i.e. diffuse overbank flows; passive overflow), and surface shear stress‐related connections (i.e. condensed flows; active overflow) during high flows. Generalised dissimilarity models indicated that floodplain invertebrate composition had complex relationships with the three processes considered. The relative importance of the latter appeared dependent upon the morphology of the floodplain channels. In the braided channels, the effects of shear stress‐related connections were more prominent than in the anastomosed ones, for which the effects of the three processes were more similar. Overall, the diversity of flow connections, that is, lateral surface water connections (both shear stress‐related and slow, as defined above) and vertical connection with groundwater (inferred through thermal inertia) enhanced the species turnover at the reach scale. Thermal inertia influenced invertebrate composition when, during low flow periods, surface flow connections had limited effect. Our results highlighted that the role of hydrologic connectivity upon floodplain diversity cannot be reduced to a single process. They also indicate the importance of vertical connectivity for maintaining biodiversity in floodplain habitats where surface flow connectivity is neither frequent nor constant.

Aquatic invertebrate diversity in tank bromeliads in an enclaved wet forest in Brazil’s semiarid region

ABSTRACT Phytotelmata bromeliads provide microhabitats for many organisms and maintain high aquatic diversity within Neotropical forests. However, they are more vulnerable to different environmental stressors that shape community structure. While most studies have been carried out in large rainforests, gaps remain about the bromeliad-dwelling community for the wettest points in the Caatinga domain (Brazilian semiarid region). Here, we investigated the influence of abiotic and temporal variables and bromeliad size on community structure between urban and forest sectors. Between 2014 and 2017, we randomly selected 20 urban and 40 forest bromeliads and compared functional groups of invertebrates for richness, abundance, and diversity. We recorded 41 morphospecies, especially Rotifera (19) and Insecta (13). Urban bromeliads exhibited higher richness of filter-feeder, while forest fragment bromeliads were dominated by predators, shredders, and gatherers. We did not observe differences in community structure regarding bromeliad size. However, the wetter period exhibited higher species richness, and higher diversity was associated with the highest rainfall. This study presents for the first time a list of aquatic microinvertebrate species and the influence of environmental parameters on the community structure associated with bromeliads of Caatinga. We have also expanded the list of species associated with phytotelmata in the Neotropical region.

When humans work like beavers: riparian restoration enhances invertebrate gamma diversity and habitat heterogeneity

Restoration has the potential to increase habitat heterogeneity through the creation of unique habitat patches that, in turn, increase regional species richness or gamma diversity. While biological diversity and habitat heterogeneity are important factors to consider under a shifting climate, restoration actions and outcomes rarely examine these components. In this study, we examined the effects of riparian beaver dam analog (BDA) restoration on aquatic invertebrate diversity and habitat heterogeneity. Although the effects of BDAs on hydrology, geomorphology, and salmonid habitat have been explored, we are unaware of any studies assessing their effects on aquatic invertebrate diversity and the food web that supports them. We sampled aquatic invertebrates, basal carbon resources, dissolved nutrients, turbidity, and water temperature in pre‐ and post‐BDA pond, side channel, and mainstem habitat over a three‐year period. The BDAs functioned similarly to natural beaver dams and created slow‐water environments that accumulated fine particulate organic material and increased pelagic phytoplankton production. Nonmetric multidimensional scaling, permutation multivariate analysis of variance, and Mantel's tests demonstrated that these changes led to the formation of a unique invertebrate community populated by lentic macroinvertebrates and zooplankton, which increased beta‐diversity and gamma diversity. Further, BDAs in our study maintained high densities of invertebrates and buffered water temperatures in comparison to adjacent lotic habitats. These results support our hypothesis that BDAs can enhance invertebrate beta and gamma diversity through the creation and colonization of unique pond habitat and improve habitat and resource heterogeneity for native fishes under variable climate conditions.

The contribution of autochthonous resource to the diet of aquatic consumers is unrelated to its spatial distribution in tank bromeliads

Autochthonous biomass is heterogeneously distributed within freshwater ecosystems, shaping community structure and ecosystem functioning, yet few studies have evaluated how the spatial heterogeneity in the availability of the autochthonous resource affects its contribution to the diets of aquatic consumers. To fill this gap, we conducted a field survey to test whether the spatial heterogeneity of the autochthonous resource within freshwater ecosystems formed in tank bromeliads determines its contribution to the diet of aquatic consumers. Tank bromeliads are Neotropical plants with densely arranged leaves in a rosette shape that accumulate rainwater and terrestrial plant material, providing suitable habitat for a diversity of aquatic invertebrates. We sampled 3 regions (north, central, and south) of the bromeliad ecosystem to provide a natural gradient in the availability of the autochthonous resource (i.e., algae biomass). To trace the diets of aquatic consumers, we used stable isotope analysis of hydrogen coupled with Bayesian stable isotope mixing models. The availability of the autochthonous resource varied among the tank-bromeliad regions with light availability, but it was not related to its relative contribution to the diets of aquatic consumers. Instead, aquatic consumers from all regions showed similarly high degrees of autochthony. The capacity of aquatic consumers to move within the plant did not affect the contribution of the autochthonous resource to their diets. We reason that the contribution of the autochthonous resource to the diets of consumers is not related to its spatial distribution because aquatic consumers preferentially feed on this resource, even when its stocks are limited. In addition, water flow among tanks could provide a subsidy of the autochthonous resource from more productive to less productive regions. We conclude that spatial heterogeneity in the availability of the autochthonous resource does not limit its contribution to the diet of aquatic consumers because of active foraging on the autochthonous resource and the flux of this resource among compartments in freshwater tank-bromeliad ecosystems.

Community structure of invasive aquatic invertebrates in coral reef ecosystems in the KKPD PISISI Simeulue

This study aimed to determine the structure of invasive aquatic invertebrates through the approach, diversity, similarity, dominance, distribution, and comparison of invasive aquatic invertebrates with coral cover in coral reef ecosystems in PISISI KKPD. This research was conducted in September 2019 using the purposive sampling method to research points, collecting invasive aquatic data used the belt transect method and collecting coral reef data used the Point Intercept Transect (PIT) method. The results of the study found that the structure of invasive aquatic invertebrates in KKPD PISISI was in the good category indicated by the density invasive aquatic invertebrates of 39.67 individuals/m2, the biodiversity index was 1.50 with the medium category, the similarity index is 1.06 in the high category and the dominance index is 0.44 in the low category. The distribution of invasive aquatic invertebrates in the PISISI KKPD includes a cluster distribution. The highest value of invasive invertebrate water was 12.83 ind/m2 and the proportion of coral cover was 29.83% and the lowest was 3.67 ind/m2 and the proportion of coral cover was 54.67% showing the effect of invasive aquatic invertebrates on the proportion of coral cover.

Формування фауни безхребетних гідробіонтів у водоймі Домбровського кар’єру в період 2014-2018 років

The aquatic invertebrate community of Dombrovskyi pit lake was investigated during 2014–2018. 25 species were recorded there. The only permanent component of plankton in the community is rotifer Brachionus plicatilis Müller, 1786; of benthos and neuston is hemipteran Sigara lateralis (Leach, 1817), beetle Hydrobius fuscipes (Linnaeus, 1758), flies Aedes sp., Ochlerotatus lepidonotus (Edwards, 1920), Culicoides salinarius Kieffer, 1914, Ephydra glauca Meigen, 1830 are permanent components of benthos and neuston. The main diversity of invertebrates is concentrated in littoral zone up to 2 m of depth. This is primarily due to the desalination of these areas by surface runoff. Over the last decade the mineralization of the surface water layer has decreased from 120–138 to 25–28 g/l. Combined with the desalination of water, the increase of species diversity of aquatic invertebrates was noticed in spring seasons (from 7 to 17 taxa). The freshwater taxa, which are not tolerant even to low water salinity, appeared in the community in 2018 (7–25 % of the species diversity), among them Hydrometra stagnorum (Linnaeus, 1758), Rhyacophila tristis Pictet, 1834, Coelambus impressopunctatus (Schaller, 1783), Enochrus coarctatus (Gredler, 1863), Hydrophilus caraboides (Linnaeus, 1758). The role of freshwater taxa, which are tolerant to low water salinity (up to 5 g/l), increased from 0–10 % of the species diversity in 2014–2015 to 22–35 % in 2018. Among them Eucyclops serrulatus (Fischer, 1851), Candona sp., Cypris pubera O. F. Müller, 1776, Cloeon dipterum (Linnaeus, 1760), Libellula depressa Linnaeus, 1758, Sympecta fusca Vander Linden, 1820, Paracorixa concinna (Fieber, 1848) was noted in 2018 for the first time. On the contrary, the number of saltwater taxa decreased from 20–29 % (2014–2015) to 5–14 % (2018). The saltwater aquatic invertebrate community of this pit lake has transformed into brakish-freshwater one over time. 83 % taxa of aquatic invertebrate communities from freshwater puddles near reservoir coast are noted in the Dombrovska reservoir. The introduction of species from protective canals of the reservoir is unlikely, as only 5 % of taxa from there are marked in it. The main way of the forming communities of invertebrates in this reservoir is the periodical flooding of freshwater coastal puddles.

Hydropeaking intensity and dam proximity limit aquatic invertebrate diversity in the Colorado River Basin

AbstractRiver biodiversity is threatened globally by hydropower dams, and there is a need to understand how dam management favors certain species while filtering out others. We examined aquatic invertebrate communities within the tailwaters 0–24 km downstream of seven large hydropower dams in the Colorado River Basin of the western United States. We quantified aquatic invertebrate dominance, richness, abundance, and biomass at multiple locations within individual tailwaters and across the basin and identified biological community responses associated with dam operations and distance from dam. We found that each tailwater was dominated by 3–7 invertebrate taxa, accounting for 95% of total abundance. Half of these dominant taxa were non‐insect, non‐flying species and thus were unavailable to terrestrial consumers. Consistent with previous studies, aquatic insects and sensitive taxa were negatively associated with hydropeaking intensity (magnitude of daily flow fluctuations associated with hydropower generation), which limits the composition and potentially the quality of the invertebrate food base. While total invertebrate abundance and biomass did not change with increasing distance downstream from dams, insect and sensitive taxa richness, abundance, and biomass all increased, suggesting that impacts of hydropeaking are most acute immediately downstream of dams. Our results demonstrate that tailwaters experiencing hydropeaking support high abundances of aquatic invertebrate, but the diversity of these communities is low.

Aquatic invertebrate assemblages during the spring-thaw season in wetlands of Northeastern China

Identifying the character and importance of invertebrates in thawing wetlands is useful, since they are the main food resource for migratory waterfowl during spring. We investigated aquatic invertebrate composition in the spring-thaw and compared it with the summer in wetlands of the Sanjiang Plain, China. NMDS analysis showed that the composition of aquatic invertebrates in the spring-thaw is significantly different from in summer. Aquatic invertebrate diversity (including Shannon–Wiener index; Margalef’s species richness; Pielou’s evenness) was lower in the spring-thaw, and Network analyses indicated that it was a simpler community. Indicator species were different between spring-thaw and summer. The scraper functional feeding group (i.e., snails) dominated both seasons, but especially in the spring-thaw. Snails and other invertebrates such as asellid crustaceans abounded in spring, are rich in both calcium and protein, making them to be an especially important food source for migratory waterfowl. Therefore, the spring-thaw should be a focus when assessing aquatic invertebrate function for waterfowl production.

Making an impact on UK farmland pond conservation

Abstract It is of vital importance that aquatic conservation is evidence based, and in the field of farmland pond management and restoration evidence was largely lacking until an article published in Aquatic Conservation: Marine and Freshwater Ecosystems (AQC) in 2012. To examine the influence of farmland pond management on aquatic biodiversity conservation, macrophyte and invertebrate diversity in ponds subject to traditional management involving scrub and occasional sediment removal at different time intervals in the past (0–2, 3–5, 6–10 years since management), were compared with a set of neighbouring, highly terrestrialized ponds that had not been managed for many decades. With the exception of Mollusca, significantly higher species diversity was found for managed ponds compared with the late‐succession unmanaged ponds, with invertebrate gamma diversity significantly lower for the late‐succession ponds, compared with all the managed pond categories. The AQC article was a key component of the Natural England (UK Government's adviser on the natural environment in England) ‘Freshwater and Wetland Conservation Narrative’ and has helped with integrating pond management into recent great crested newt Triturus cristatus mitigation policy as well as bringing it to the fore in past and evolving agri‐environment policy. The AQC article provided the evidence and in turn the confidence for the authors and a number of conservation partners to form a Norfolk Ponds Project. Since 2014, the Project has delivered or facilitated more than 100 pond restorations in Norfolk, eastern England, as well as educating conservation practitioners and farmers on the importance of farmland ponds via various events. With good underpinning science it has been possible to achieve considerable impact in the field of farmland pond conservation. This study shows the importance of setting aside time and support for academic staff to translate applied research outputs into practical impact.

Effects of urban infrastructure on aquatic invertebrate diversity

Wetlands are one of the world’s most important, economically valuable, and diverse ecosystems. A major proportion of wetland biodiversity is composed of aquatic invertebrates, which are essential for secondary production in aquatic and terrestrial food webs. Urban areas have intensified the challenges wetlands encounter by increasing the area of impermeable surfaces and the levels of nutrient and pollutant overflows. We investigated how urban infrastructure affects the aquatic invertebrate fauna of urban wetlands in metropolitan Helsinki, southern Finland. We measured riparian canopy cover, emergent vegetation coverage, and various land cover and road variables. Recreation area, forests, and open natural areas were the most important landscape features positively influencing aquatic invertebrate family richness, whereas buildings and roads had a negative effect on family richness and abundances of many taxa. Recreation area and the various forest types also positively affected the α-diversity indices of wetlands. On the other hand, fish assemblage did not affect either family richness or abundances of the studied taxa. Furthermore, trees growing on the shoreline negatively affected the diversity of aquatic invertebrate families. Invertebrate family diversity was greatest at well-connected wetlands, as these areas added to the regional species pool by over 33%. Our results show that connectivity and green areas near wetlands increase aquatic invertebrate family diversity, and our results could be utilized in urban planning.Graphical abstract

Comparison of invertebrate diversity in lake waters and their resting eggs in sediments, as revealed by high-throughput sequencing (HTS)

Aquatic invertebrate diversity reflects water quality and the health of aquatic ecosystems and should be monitored as an essential feature of freshwater ecosystems. The resting eggs of aquatic invertebrates in sediments populate the overlying water. The diversity of invertebrates in waters and their resting eggs in sediments in Baiyangdian Lake, Xiongan, North China, were assessed using high-throughput sequencing (HTS) with a pair of 18S rRNA gene adaptor-linked primers. The total of 99 operational taxonomic units (OTUs) derived from 353,755 invertebrate sequences (mostly zooplankton) were revealed by this study. A total of 50 species in the water samples including 20 rotifers, 11 copepods, 1 cladoceran and 18 other species were sorted out. In the sediment 37 species, including 21 rotifers, 3 copepods, 1 cladoceran and 12 other species, were identified. There were 24 species in common between water and corresponding sediments. Invertebrate OTU richness in water samples was higher than that in sediments (p < 0.01), while there was no significant difference in the Shannon-Wiener index. These results suggest that HTS is a promising alternative for efficient biodiversity assessment and monitoring.

Global meta‐analysis reveals that invertebrate diversity is higher in permanent than in temporary lentic water bodies

Abstract One of the main constraints affecting invertebrate diversity in many freshwater lentic habitats is the presence of a dry phase which forces aquatic organisms to avoid this period through the migration to other water bodies or the production of resting stages. Field studies show contradictory results when comparing invertebrate diversity in permanent (PW) and temporary lentic waters (TW). Our objective was to test how diversity is influenced by the permanence of water in lentic habitats, and which factors affect the magnitude and direction of this difference, including sampling design. Through a systematic review, 66 publications were selected and classified according to the sampling design (spatial, temporal, and spatio‐temporal datasets). Meta‐analysis of the spatial dataset, which included 70% of the studies, revealed that diversity in PW was higher than in TW, and this difference was not influenced by annual precipitation, dispersal mode, habitat type or level of anthropogenic impact (proximity to urban or agricultural areas). We found a significantly higher effect size (PW greater than TW) when considering species richness rather than cumulative richness or Shannon diversity index, disconnected water bodies (hindering the exchange of individuals through water connection), organisms with passive dispersal (which cannot actively avoid the dry period), and study sites with high anthropogenic impact (where temporary habitats could undergo impacts; e.g. concentration of pollutants and eutrophication). We also found that the differences in diversity between PW and TW may decrease with increasing sampling effort. This result may be attributable to high species turnover due to the higher temporal environmental variation in TW relative to PW. Also, it indicates that sampling effort should be comparatively higher in TW to properly characterize the biodiversity in these environments in order to compare with PW. As global climate continues to change, our results suggest that loss in aquatic invertebrate diversity of TW will be likely to occur in regions where the frequency of drying events increases.

Management of Invasive Water Hyacinth as Both a Nuisance Weed and Invertebrate Habitat

Author(s): Donley Marineau, Erin; Perryman, Matthew J.; Lawler, Sharon P.; Hartman, Rosemary K.; Pratt, Paul D. | Abstract: Invasive species have many detrimental ecological and socio-economic effects. However, invasive species can also provide novel habitat for native species. The growing rate of biological invasions world-wide presents an urgent dilemma: how can natural resource managers minimize negative effects of invasive species without depleting native taxa that have come to rely on them? Adaptive management can provide a means to address this dilemma when invasive species management plans are crafted in novel environments. We present a case study of research in support of adaptive management that considers the role of invasive water hyacinth (Eichhornia crassipes [Mart.] Solms [Pontederiaceae]) management, using herbicides, in aquatic food web functioning in the Sacramento–San Joaquin River Delta of California, USA (the “Delta”). We hypothesized that herbicide applications under current management protocols would reduce the abundance and diversity of aquatic invertebrates because they would alter both structural and biological habitat. Using a Before, After, Control, Intervention (BACI) experiment, we sampled invertebrates per gram plant biomass before and 4 weeks after glyphosate applications in treated and untreated locations. There was more plant biomass in the late-season samples because dead, dying, and living plant materials were compacted. However, there were no detectable differences between control and treated sites — or for samples before versus after the treatment date—for invertebrate abundance, species richness, or evenness. This case study demonstrates that even decaying water hyacinth serves as habitat for invertebrates that may be forage for Delta fishes. We concluded that current management practices using glyphosate do not affect invertebrate abundance during a month-long period of weed decay. These results provide valuable feedback for the “evaluate and respond” component of the adaptive management process for water hyacinth control, and demonstrate how managers globally can and should consider potential food web effects in the course of their invasive species management efforts.