Public science data suggest that fish is the most important factor in reducing small pond biodiversity in Czechia

This project tested a public-science approach to the assessment of freshwater habitat quality via simple invertebrate sampling. We combined a mobile phone application and simple instruction to children to sample 50 ponds in Central Czechia, and we analyzed the data using a standard ecological statistics approach. Despite the limitation in scope and taxonomic precision, our data revealed the same patterns as academic studies of the same topic. Specifically, we conclude that the main cause of invertebrate community decline is fish overstocking, while diverse invertebrate communities require aquatic macrophytes. Pollution detectable by children has an effect on invertebrate community structure, but a different effect than fish has, and not as statistically robust. Importantly, almost all large ponds were found overstocked with fish; therefore they support not more diversity than small ponds, but less, and serve as ecological traps. Our findings suggest that pond conservation should focus primarily on the restoration of aquatic vegetation, and that the most effective approach will be the removal of excessive fish.

Komunitas makroinvertebrata bentik di perairan Situ Cibuntu, Jawa Barat

Situ Cibuntu, is one of urban ponds located in Bogor Regency, West Java. With a maximum surface area of 11 ha and maximum depth of 1,20 m, the pond serves as irrigation for nearby agricultural fields and recreational fishing. Located in relatively high urban pressure, the pond is highly affected by domestic, agricultural and industrial inflow which can influence the biotic community such as benthic macroinvertebrate. We studied benthic invertebrate community structure in Situ Cibuntu from October to November 2018 to determine the role of environmental factors on benthic macroinvertebrates. Samples were collected biweekly from five sampling points using an Ekman sediment grab with three replicates. Our study revealed 16 species of benthic macroinvertebrates belonging to four classes including Gastropoda, Bivalvia, Clitellata, and Insecta. Melanoides tuberculata species was found to have the highest abundance with an average abundance of 858 individuals/m2. Shanon-Wiener Diversity Index shows a relatively low diversity ranged from 0.61 to 1.26, while evenness index ranged from 0.36 to 0,66. Simpson Dominance Index ranged from 0.24 to 0.93.Keywords:DominanceCommunityAbundanceDiversityBenthic MacroinvertebratePond CibuntuABSTRAKSitu Cibuntu merupakan salah satu situ urban (urban pond) yang terletak di Kabupaten Bogor, Provinsi Jawa Barat. Situ Cibuntu yang memiliki luas permukaan 2,11 ha dengan kedalaman maksimum 1,20 m dimanfaatkan sebagai sumber irigasi pertanian dan sarana pemancingan ikan. Situ di kawasan perkotaan dapat mengalami tekanan karena pengaruh limbah domestik, pertanian, dan industri yang dapat mempengaruhi komunitas biotik seperti makroinvertebrata bentik. Penelitian ini bertujuan untuk mengetahui komunitas makroinvertebrata bentik di perairan Situ Cibuntu. Penelitian dilakukan pada bulan Oktober hingga November 2018 di lima stasiun pengamatan. Pengambilan sampel dilakukan sebanyak tiga kali dengan interval waktu dua minggu. Sampel makroinvertebrata bentik diambil dari sedimen pada setiap stasiun dengan menggunakan Ekman grab sebanyak tiga kali ulangan. Secara keseluruhan ditemukan 16 spesies makroinvertebrata bentik yang tergolong ke dalam empat kelas meliputi Gastropoda, Bivalvia, Clitellata, dan Insekta. Spesies Melanoides tuberculata memiliki kelimpahan tertinggi dengan nilai rata-rata sebesar 858 individu/m2. Keanekaragaman makroinvertebrata bentik tergolong rendah hingga sedang dengan nilai indeks Shanon Wiener (H’) berkisar 0,61-1,26. Nilai indeks kemerataan Pielou (E) berkisar 0,36-0,66, sedangkan indeks dominansi Simpson (D) berkisar 0,24-0,93.Katakunci:DominansiKomunitasKelimpahanKeanekaragamanMakroinvertebrata bentikSitu Cibuntu

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<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.

The role of microhabitats in structuring cave invertebrate communities in Guatemala

Several studies have tried to elucidate the main environmental features driving invertebrate community structure in cave environments. They found that many factors influence the community structure, but rarely focused on how substrate types and heterogeneity might shape these communities. Therefore, the objective of this study was to assess which substrate features and whether or not substrate heterogeneity determines the invertebrate community structure (species richness and composition) in a set of limestone caves in Guatemala. We hypothesized that the troglobitic fauna responds differently to habitat structure regarding species richness and composition than non-troglobitic fauna because they are more specialized to live in subterranean habitats. Using 30 m2 transects, the invertebrate fauna was collected and the substrate features were measured. The results showed that community responded to the presence of guano, cobbles, boulders, and substrate heterogeneity. The positive relationship between non-troglobitic species composition with the presence of guano reinforces the importance of food resources for structuring invertebrate cave communities in Guatemalan caves. Furthermore, the troglobitic species responded to different substrate features when compared to non-troglobitic species. For them, instead of the presence of organic matter, a higher variety of abiotic microhabitats seem to be the main driver for species diversity within a cave. The high specialization level of troglobitic organisms might be the reason why they respond differently to environmental conditions. The findings of this study highlight the importance of biological surveys for understanding cave biodiversity and give insights on how this biodiversity might be distributed within a cave. Conservation measures should keep in mind the target organisms and if such measures aim to protect a broad variety of organisms, then one should aim to preserve as many microhabitats and trophic resources as possible.