Avian schistosome species in Danish freshwater lakes: relation to biotic and abiotic factors

Due to the increased prevalence of human infections with bird schistosome larvae (cercarial dermatitis) associated with bathing in Danish lakes, a nationwide survey of infected intermediate host snails was conducted in 2018–2020. Pulmonate snails (10,225 specimens) were collected from 39 freshwater lakes (in the four major geographic regions in Denmark) and subjected to shedding. Released schistosome cercariae were isolated and identified by polymerase chain reaction and sequencing whereby Trichobilharzia regenti, Trichobilharzia franki, Trichobilharzia szidati and Trichobilharzia anseri were recorded. Infections were primarily determined by biotic factors such as the presence of final host birds and intermediate host snails and water temperature was noted as an important abiotic parameter associated with the infection. No clear connection with other abiotic factors (conductivity, alkalinity, pH, nitrogen, phosphorous) was seen. The widespread occurrence of infected snails, when compared to previous investigations, suggests that climate changes at northern latitudes could be responsible for the increased risk of contracting cercarial dermatitis.

Effect of Abiotic Parameters on Vegetable Storability

India is the second-largest producer of vegetables. However, vegetables are critical for storage, due to their highly perishable nature, lack of cold storage and transportation facilities. Vegetables get shrivel, whither rapidly, especially under hot conditions, if not preserved just after harvest. The study was conducted at ICAR-IARI to access the effect of abiotic parameters on vegetable quality with time. Effect of abiotic parameters on vegetable storability was studied and statistical analysed results revealed that there was a significant difference (P=0.05) in storage parameters occur when vegetables stored at different temperature and relative humidity. Storability parameters physiological loss in weight (PLW), firmness, colour values and total soluble solids (TSS) of vegetables tomato, spinach, and radish with different temperature and relative humidity were determined. The effect of abiotic parameter i.e. temperature and relative humidity on PLW physiological loss in weight was found significantly different at 5% level of significance. Temperature reduction of 5 – 10°C and RH increment of 10% have a significant effect on quality parameters i.e. PLW, TSS, colour values of vegetables PLW of vegetables and TSS showed an increasing trend with an increase in temperature and decrease in relative humidity. The firmness of tomato and radish showed a decreasing trend with the increase in temperature and decrease in relative humidity but spinach firmness trend was found the opposite. Thus control over these abiotic parameters is essential to retain the quality of the vegetables and prevent their spoilage.

Dragonfly Diversity (Insect: Odonata) in Asem Binatur River, Pekalongan, Indonesia

Dragonflies have an essential role in the aquatic ecosystem. The nymph phase lives in water and is sensitive to environmental changes. The reduced number of dragonflies in an area can be an indication of changes in the quality of water and environmental health. This research was conducted in the Asem Binatur River, Pekalongan, Indonesia, from November 2018 to April 2019. The purpose of this study was to determine species diversity, the index value of the Pekalongan River dragonfly diversity by using the point count method. Long hand high net, wrapping paper/papilot and camera were used to catch and observe the dragonflies. The Shannon-Wiener species diversity index was calculated. Seven species of dragonflies were recorded from Asem River. There were Orthetrum sabina, Diplacodes trivalis, Neurothemis ramburii, Crocothemis servilia, Pantala flavescens, Neurothemis stigmatizans and Orthetrum chrysis. The Shannon-Wiener diversity index analysis was ranged from 0 to 0.31, indicating low diversity. Abiotic parameter measurements showed the humidity was 67.17%, the soil pH was 7.11, the light intensity was 46310 lux and the temperature was 30 °C. The analysis of the dragonfly diversity index was correlated with the poor water quality status in Asem Binatur River, Pekalongan.

A pilot study for monitoring the zoobenthic communities on the rocky shores of Abra de Bilbao (northern Spain)

Biomass measurements (AFDW) of both subtidal and intertidal macrofauna of the ‘Abra de Bilbao’ embayment were used within a pilot study in a four step strategy of analysis, which consisted of: (1) representing communities; (2) discriminating sites or conditions; (3) determining levels of ‘stress’; and (4) linking to environmental variables. Univariate (number of species, diversity indices) as well as multivariate (clustering, MDS, SIMPER, BIO-ENV) techniques from the PRIMER package were employed. Several data aggregation levels were proposed in the analyses with the aim of selecting cost-effective procedures. The results suggested a good integration of environmental conditions by subtidal samples, which were close to constant on all different taxonomic aggregation levels. The abiotic parameter which best ‘explained’ the biotic pattern of subtidal samples in the investigated area was turbidity measured as total suspension solids and nephelometric units on the water surface. In conclusion, we recommend monitoring rocky substrates by using more extensive biomass sampling surveys of subtidal areas followed by a less time-consuming treatment of the samples (identification by high taxonomic categories or by trophic groups).