Decreasing Richness And Biomass During A Flood Pulse Observed In A Southeastern US Coastal Floodplain Following A Multi-Year, Supra-Seasonal Drought

Floodplains of the southeastern United States exhibit high biological productivity, maintained by periodic floodplain inundation as a result of seasonal flooding. To examine the relationship between biological productivity and seasonal flooding following periods of drought, we quantified aquatic macroinvertebrate communities monthly in an inundated floodplain during the annual flood pulse (December-April) in two years, one following a multi-year drought and one following a larger than average flooding event. We predicted that floodplain communities would differ in richness, biomass, and community composition between years and that differences would be driven by discharge at the main stem and organic matter availability. We collected macroinvertebrates from the floodplain of the Altamaha River, an unimpounded 6th order river in the Coastal Plain region of the southeastern US that experiences floodplain connectivity. With invertebrates identified to genus, we elucidated richness, abundance, biomass, community composition, and functional feeding group. Richness was generally higher in the drought year but decreased throughout the flood pulse, while during the flood year richness was lower and increased. Biomass decreased throughout the flood pulse following the drought year and increased during the flood year. There was a high degree of overlap in invertebrate community composition based on abundance data during both years of the study with collector gatherers being the most highly abundant functional feeding group. As climate change impacts (i.e., severe droughts) become more common, it is critical to investigate how aquatic communities are responding to increasingly unpredictable flow conditions in unimpounded and seemingly unaltered rivers.

The Trophic Basis of Fish Assemblages in Temperate Estuarine and Coastal Ecosystems

More than half of the fish biomass of coastal rocky reefs depends on zooplankton; however, the trophic basis of estuarine fish assemblages remains unknown. We quantified the trophic basis (i.e. basal energy sources) of fish community biomass inhabiting three habitat types (seagrass, natural reef and artificial reef) in two estuaries, and at two coastal rocky reef sites. Estuarine fish assemblages were surveyed with Baited Remote Underwater Video (BRUVs). Species abundance, richness and biomass of fish were classified into 9 functional feeding groups (3 elasmobranch and 6 teleost). Comparable metrics for coastal fish assemblages were obtained from published surveys using BRUV, remote underwater video and visual census survey methods. Using the functional feeding group biomass and the group-specific diet composition, the breakdown of energy sources was calculated using a food web analysis. Estuarine reef habitats had different species and different functional feeding group composition than seagrass habitat. The majority of fish biomass in the seagrass habitat was supported by detritus (51% at one estuary) or macrophytes (58% at the other estuary). In contrast, zooplankton supported most fish biomass (45-59%) at the coastal reef locations, and in reef habitat in one estuary (35-43%), but not the other estuary (33-34%). The trophic basis of estuarine and coastal fish assemblages reveals their potential response to urbanisation including changes to habitat, nutrient supply and current flow.

Functional Feeding Group composition and attributes: evaluation of freshwater ecosystems in Atlantic Forest, Brazil

Benthic macroinvertebrates Functional Feeding Group (FFG) have been used to determine aquatic assemblage dynamics and as a biomonitoring tool. The main goals of this study were to assess the effects of stream variables on the abundance and richness of FFGs and evaluate ecosystem attributes (FFG ratios) as a tool to assess ecological conditions of Atlantic Rainforest streams. We sampled 146 sites with different impairment conditions in Rio de Janeiro, Brazil. Richness was significantly different among impairment conditions for all FFGs. Mixed-effect models show that aquatic macroinvertebrate FFGs differed in their responses to abiotic variables for abundance and richness. Also, they were reduced in the impaired sites when compared to intermediate and reference sites. The FFG ratio indicated significant differences along the impairment gradient. The FFG ratio analysis was shown to be a fast and cheap tool that can be used for monitoring aquatic ecosystems in the Atlantic Forest biome. However, further studies are required to calibrate the method specifically for the Atlantic Forest region.

KOMUNITAS MAKROZOOBENTOS DI KAWASAN PENAMBANGAN PASIR DI SUNGAI PROGO (Macrozoobenthos Community in Sand Mining Area of Progo River)

AbstrakSungai memiliki peranan penting bagi manusia dan makhluk hidup lainnya, di antaranya adalah sebagai habitat bagi komunitas makrozoobentos dan pemanfaatan material berupa pasir dan batu sebagai bahan bangunan. Sungai Progo merupakan salah satu sungai yang hampir di sepanjang sungainya terdapat aktivitas penambangan pasir. Jika aktivitas ini dilakukan terus menerus dalam jumlah banyak dan tanpa pengawasan yang baik dapat menyebabkan terjadinya erosi dan degradasi serta sedimentasi pada bagian-bagian tertentu sungai. Maka dari itu dilakukan penelitian ini untuk mempelajari pengaruh aktivitas penambangan pasir terhadap distribusi dan kemelimpahan komunitas makrozoobentos di Sungai Progo, serta Functional Feeding Group (FFG) yang paling melimpah dan parameter fisiko-kimia yang memengaruhinya. Penelitian ini dilakukan dalam tiga tahap, yaitu mencuplik dan preparasi sampel makrozoobentos, identifikasi sampel, dan pengukuran parameter fisiko-kimia. Aktivitas penambangan pasir di Sungai Progo berpengaruh secara tidak langsung terhadap makrozoobentos, yaitu dengan menyebabkan adanya erosi dan degradasi di kawasan penambangan pasir serta sedimentasi di bagian hilir. FFG makrozoobentos di Sungai Progo yang paling melimpah adalah tipe scraper dan collector. Berdasarkan analisis regresi dan korelasi Pearson didapatkan hasil bahwa fosfat berkorelasi positif terhadap densitas makrozoobentos di bagian hulu Sungai Progo, intensitas cahaya berkorelasi positif terhadap densitas makrozoobentos di bagian tengah Sungai Progo, dan kecepatan arus berkorelasi positif terhadap densitas makrozoobentos di bagian hilir Sungai Progo. AbstractRiver has an important role for human and other organisms, among them are as habitat of macrozoobenthos community and the utilization of the material, such as river sand and gravel for building material. Progo River is one of rivers which have sand mining activities almost all along the river. If this activity being done continuously, in a big amount and without a good supervision, it could lead to erosion, degradation and sedimentation in some specific parts. Therefore, this research has an aim to study the effects of sand mining activity towards the distribution and the abundance of macrozoobenthos community in Progo River, and also to study which Functional Feeding Group (FFG) is the most abundant and the physic-chimic parameter that affecting them. This research was conducted in three steps, sampling and preparation of macrozoobenthos’s sample, sample’s identification, and the measurement physicochemical parameter. Sand mining activity in Progo River effect indirectly towards macrozoobenthos by causing erosion and degradation in sand mining area as well as sedimentation in downstream. The most abundant FFG of macrozobenthos in sand mining area of Progo River are scraper and collector. Based on regression and Pearson correlation analysis the results show that phosphate correlated positively against the density of macrozoobenthos in the headwaters of Progo River, light intensity correlated positively against the density of macrozoobenthos in the midstream of the Progo River, and current velocity correlated positively against the density of macrozoobenthos in the downstream of the Progo River.

Impact of ecological attributes and feeding categorization of Ephemeroptera, Plecoptera and Trichoptera (EPT) insects in Kiliyur falls of Eastern Ghats, India

Investigation on the diversity, ecology and trophic categorization of Ephemeroptera, Plecoptera and Trichoptera complex (EPT) was carried out in Kiliyur falls of the Eastern Ghats. An aggregate of 2,189 specimens belonging to 24 genera, 12 families and 3 orders were collected. Ephemeroptera was found to be high when compared to Plecoptera and Trichoptera. Baetidae was the most abundant taxa of all with presence of 5 genera and 6 species. Shannon-Weiner index and Simpson’s index were calculated and it shows that Shannon-Weiner index was elevated in the August (2.882) and declines in January (2.744). Simpson’s index was most noteworthy in December (0.9325) and it was least in January (0.9321). Canonical correlation analysis (CCA) shows that temperature, dissolved oxygen and rainfall turns into a major stressor in the EPT community of Kiliyur falls. Cluster analysis results prove that Baetidae and Caenidae shows comparative dispersion pattern as opposed to Teloganodidae and Perlidae. Functional feeding group (FFG) analysis shows that Kiliyur stream was overwhelmed by collectors followed by scrapers, predators and filter-feeders.

Distribution of mayflies in thirty streams of Western Ghats, Southern India

Mayflies are recognized as potential bioindicators of good water quality and they are not widely been studied in Indian subcontinent. So the current paper aims to describe the distribution and trophic categorization of mayflies in connection with stream order, mesohabitats and landscape elements. The study was carried out in 30 streams of Palni and Cardamom hills of Southern India from 2017–2018. A total of 10,075 individuals of mayflies were collected from 30 sites. The species richness among the six landscape elements (evergreen, semi evergreen, forestry plantation, areca nut, scrub and habitation) were examined and the outcomes show that streams moving through evergreen territories have more richness (25.6%) followed by semievergreen regions (23.2%) and no mayflies are acquired from pool. PCA results showed that among the mesohabitats; run, riffle and bank underpins the mayfly taxa. Functional Feeding Group (FFG) results shows 27 sites were overwhelmed by scrapers, 2 sites were dominated by collectors and in one site collectors and scrapers were equivalent. Ternary plot reveals scrapers were found to be predominant in all the stream orders. The present study also revealed that in Palni and Cardamom hills, larger numbers of species of Ephemeroptera were sampled from stream orders II and III contrast with stream orders I and IV. Key words: Ephemeroptera, RCC, scrapers, arecanut, FFG