Bioaccumulation of auto-mechanic wastes in the tissues of Pellonula Afzeliusi (Johnels, 1954) collected from Agba stream Ilorin, Kwara State, Nigeria

Hydrocarbons and heavy metals (HM) present in automobile wastes get into water bodies close to automobile mechanic villages. They deteriorate the physico-chemical qualities of such water bodies and exert toxic effects on fish and other aquatic fauna. They also pose risks to humans that consume fish from streams near such automechanic villages. There is paucity of information on the HM contents of Agba stream, Ilorin and no information on the bioaccumulation of HM in the tissues of Pellonula afzeliusi is currently available. The purpose of this study was to assess the physico-chemical qualities of water and bioaccumulation of HM in the tissues of Pellonula afzeliusi fish collected from Agba stream, Ilorin, Kwara State, Nigeria. Water and samples of Pellonula afzeliusi were collected from the upstream (station A), midstream (station B) of Agba stream located close to an auto-mechanic village and Oyun dam (control site, station C) located within the University of Ilorin. Standard methods were used to analyse oil and grease (OG), total petroleum hydrocarbon (TPH) and HM in water samples. The concentrations of TPH and HM were analysed in the skin, bone, muscle, gills, gastrointestinal tract, liver and kidney of the fish. The order of water HM concentrations indicated Zn > Cd > Ba> Fe > Pb at station A; Cd > Zn > Fe > Ba > Pb at station B, and Zn > Ba > Pb > Fe >Cd at station C. TPH and HM bioaccumulated in the tissues of fish while lead was not detected in all tissues from station C. Bioaccumulation factor varied with the highest values t station C. The result of this study indicated heavy pollution burden in station B with lower pollution burden in station C (the control site). These call for attention of government in ensuring ecological restoration and prevention of further discharge of automobile wastes into the stream. Keywords: Automobile wastes, Heavy metals, Hydrocarbons, Bioaccumulation, Pellonula afzeliusi

Changements historiques à long terme du débit écoulé dans le Haut bassin du fleuve Sénégal

In this study, the flow trends on either side of the Manantali dam, in the upper Senegal River basin, were assessed. The assessment was carried out for the period 1970 to 2019 using the Sen slope and the Mann-Kendall test. The Mann-Kendall trend test was used to indicate the direction of the trends, while the Sen slope was used to assess the magnitude of the change. The results of the study showed that there was an upward trend in the flow of the Senegal River both annually and for every month upstream (Bafing-Makana station) and downstream (Bakel station) from the barrage. The strongest upward trend is noted in October on the upstream station with 4.12 m3/month and in September on the downstream station with 10.99 m3/month. In return, the weakest upward trend is observed in May on the upstream station with 0.07 m3/month and in August on the downstream station with 0.67 m3/month. The annual flow also showed a significant increase upstream (with a rate of 0.35 m3/year) and downstream (with a rate of 4.53 m3/year) with a confidence level of 99 %. The results of the study also showed that an increase in precipitation causes an increase in runoff, despite the construction of hydraulic structures.

AQUATIC MACROINVERTEBRATE STRUCTURE AND DIVERSITY IN ANGUEDEDOU STREAM (ANGUEDEDOUBASIN : COTE DIVOIRE)

Aquatic macroinvertebrates play an important rôle in ecosystems and are usually used as bioindicators to assess their health. This study aim to assess the structure and diversity of these organismson one hand and the effect of the environmental variables on the characteristics of their communities in Anguededou Stream basin (Côte dIvoire) on the other hand. Six stations were monthly sampled during one year period (March 2018 - February 2019). A total of 171 taxa belonging to 77 famillies and 14 orders were recorded. The Insecta class was the most diversified with 150 taxa (87.20% of total species richness) followed by the Gasteropoda, Malacostraca, Acheta and one species in Oligocheta. The highest values of diversity indices were collectedin the upstream station A1 while highest values of Sorensen similarity index were found between the midstream stations (i.e. A3, A4, A5). A strong positive correlation between conductivity, turbidity, salinity, and a negative correlation with dissolved oxygenwas found with the Chironominae subfamily, and the species Diplonychus sp., Hydrobius sp., Hydracharina sp., Hydrochara sp. and Physa marmorata, while the Tanypodiinae subfamily was highly associated with increased of dissolved oxygen. Macroinvertebrates diversity and species composition was found significantly affected by anthropogenic disturbances.

Epipelic cyanobacterial diversity in Pinang River basin, Malaysia, revealed by 16S-based metagenomic approach

Cyanobacteria are the most widespread group of photosynthetic prokaryotes. They are primary producers in a wide variety of habitats and are able to thrive in harsh environments, including polluted waters; therefore, this study was conducted to explore the cyanobacterial populations inhabiting river tributaries with different levels of pollution. Sediment samples (epipelon) were collected from selected tributaries of the Pinang River basin. Air Terjun (T1) and Air Itam rivers (T2) represent the upper streams of Pinang River basin, while Dondang (T3) and Jelutong rivers (T4) are located at in the middle of the river basin. The Pinang River (T5) is located near the estuary and is subjected to saline water intrusion during high tides. Cyanobacterial community was determined by identifying the taxa via 16S rRNA gene amplicon sequence data. 16S rRNA gene amplicons generated from collected samples were sequenced using illumina Miseq, with the targeted V3 and V4 regions yielding approximately 1 mln reads per sample. Synechococcus, Phormidium, Arthronema and Leptolyngbya were found in all samples. Shannon-Weiner diversity index was highest (H’ = 1.867) at the clean upstream station (T1), while the moderately polluted stream (T3) recorded the lowest diversity (H’ = 0.399), and relatively polluted stations (T4 and T5) recorded fairly high values of H’. This study provides insights into the cyanobacterial community structure in Pinang River basin via cultivation-independent techniques using 16S rRNA gene amplicon sequence. Occurrence of some morphospecies at specific locations showed that the cyanobacterial communities are quite distinct and have specific ecological demands. Some species which were ubiquitous might be able to tolerate varied environmental conditions.

Metal Concentrations in Sediments of the Alinsaog River, Santa Cruz, Zambales, Central Luzon, Philippines

Background. Efforts are needed to evaluate heavy metal concentrations in aquatic sediments which serve as repositories and as sources of contamination of other habitats. Objectives. The present study assessed temporal changes in the pH, particle size and concentration of metals in sediments of a mining-affected river in Zambales, Philippines. Methods. Sediment samples were collected at different periods in four stations along the river using a modified Van Veen grab. The samples were subjected to quartering, air-drying, and sieved through a mesh of 40 mm prior to X-ray fluorescence spectroscopy analysis using Thermo Scientific Niton XL3t to determine metal concentrations. The sediment particle size was analyzed by the sieve method and soil pH by the electrode method. Results. Measured metal concentrations in the sediment were as follows: iron (Fe)> calcium (Ca)> chromium (Cr)> nickel (Ni)> manganese (Mn) with averages of 174.6 mg/g, 7.89 mg/g, 6.54 mg/g, 4.82 mg/g, and 2.75 mg/g dry matter (DM), respectively. The mean pH of riverine sediments was generally neutral, except for Station 4. In terms of particle size, silt and clay fractions increased in the upstream station but decreased in the midstream and downstream stations across the sampling periods. The flooding brought by Typhoon Koppu resulted in lowered concentrations of Fe, Mn, Cr, and Ni and an upsurge in Ca and potassium levels. Discussion. Most of the heavy metals (Fe, Ni, Cr, Mn) exceeded the probable effect level (PEL) for inorganics in sediments, suggesting that the adverse effects of these metals on the environment and aquatic organisms are expected to occur frequently. In comparison with Station 4, which was less affected by siltation, there was a sign of metal enrichment in the area. This indicates that soil erosion and runoff, which might have been triggered by vegetation loss, mineral extraction, and agricultural activities, had a significant impact on the quality of river sediments. Conclusions. The findings of the study point to the need for the formulation and implementation of appropriate regulatory measures for the protection and rehabilitation of the heavy metal-loaded river. Competing Interests. The authors declare no competing financial interests.

Distribution of zooplankton community in Toli shad (Tenualosa toli) habitats, Sarawak, Malaysia

Aiman WM, Yusoff FM, Arshad A, Kamal AHM, Ismail J, Idris MH, Karim NU, Asif AA. 2020. Distribution of zooplankton community in Toli shad (Tenualosa toli) habitats, Sarawak, Malaysia. Biodiversitas 21: 4022-4033. The river ecosystems of Sarawak has been identified as important-spawning ground for economically important Toli shad (Tenualosa toli) fisheries. In these river ecosystems, zooplankton serves as a secondary producer to the different types of fish larvae including Toli shad. The productivity and biomass of zooplankton are important factors to control the production of higher trophic level organisms like fish larvae and fishes in different stages including T. toli larvae. In this viewpoint, the composition and abundance of zooplankton were investigated at 5 (five) sampling stations (considered to be spawning and nursing areas of Toli shad) at Batang Lupar and Batang Sadong estuaries from July 2016 to June 2017. A total of 29 zooplankton taxa were recorded that belong to 14 major groups comprised of Copepoda (Arthropoda), Crustacean nauplii (Arthropoda), Fish larvae (Chordata), Mollusca (Mollusca), Luciferidae (Arthropoda), Cnidaria (Cnidaria), Ostracoda (Arthropoda), Cirripedia (Arthropoda), Polychaete larvae (Annelida), Chaetognatha (Chaetognatha), Appendicularia (Chordata), Amphipoda (Arthropoda), Echinodermata larvae (Echinodermata) and Cladoceran (Arthropoda). Copepod was dominant group of zooplankton (82.40-94.41%) at all stations, contributing 477.37-25921.89 ind/m3 and 88.38% of total abundance. The second highest was crustacean larvae (2.45-9.38%) in all stations, contributing 0-2391.7 ind/m3 and 5.88% of total abundance. Zooplankton abundance was higher at downstream station 1 (8460.72 ind/m³) followed by station 2 (5479.80 indi/m³), station 3 (4571.95 ind/m³), station 4 (4394.20 ind/m³) and upstream station 5 (4156.73 ind/m³). Canonical Correspondence Analysis showed that the abundance of copepods was highly influenced by total turbidity and nitrate in the riverine and estuarine ecosystems. Abundance of zooplankton was relatively higher (9549.31 ind/m³) during the post-monsoon and lower (3534.56 ind/m³) during the southwest monsoon.

PERKIRAAN WAKTU KEDATANGAN BANJIR BERDASARKAN ANALISIS EMPIRIK REKAMAN DATA SISTEM PERINGATAN DINI BANJIR KOTA BEKASI

Flood disaster that occur in the Kali Bekasi watershed often cause damage of property and casualties. The watershed is divided into two main parts namely upstream and downstream watersheds which are limited by Bekasi Dam. High rainfall in the upstream often causes flooding in Pondok Gede Permai Estate, Bekasi City. To improve community preparedness, a flood early warning system (FEWS) has been installed which consists of 5 monitoring stations along the Cileungsi and Cikeas Rivers in 2017. The main question that needs to be answered in this paper is how long the upstream flood peak will reach community settlements ? Based on the recorded data on the LEWS instrument, the flood peak travel time from the upstream station to the affected area can be calculated empirically. The results ofthe time calculation can be used by stakeholders to carry out evacuation after an early warning is given. The parameter used in this analysis are the river water level at several monitoring stations on the Cileungsi River, namely: Cibongas Irrigation Dam,WIKA Bridge and Pondok Gede Permai.Bencana banjir yang terjadi di DAS Bekasi sering menimbulkan kerugian harta benda maupun korban jiwa. DAS ini terbagi atas dua bagian utama yaitu DASbagian hulu dan bagian hilir yang dibatasi oleh Bendung Bekasi. Curah hujan yang tinggi di DAS bagian hulu sering menimbulkan banjir di Perumahan Pondok Gede Permai, Kota Bekasi. Untuk meningkatkan kesiapsiagaan masyarakat di perumahan tersebut, maka telah dipasang sistem peringatan dini banjir (Flood Early Warning System/LEWS) yang terdiri dari 5 stasiun pemantauan di sepanjang Sungai Cileungsi dan Cikeas pada tahun 2017. Pertanyaan utama yang perlu dijawab dalam makalah ini adalah berapa lama puncak banjir di bagianhulu akan mencapai permukiman masyarakat ? Berdasarkan basis data yang telah terekam pada instrument LEWS tersebut, waktu perjalanan puncak banjir dari stasiun hulu menunju area terdampak dapat dihitung secara empirik. Hasil perhitungan waktu tersebut dapat dimanfaatkan oleh para pemangku kepentingan untuk melakukan evakuasi setelah peringatan dini diberikan. Parameter yang digunakan dalam analisis ini adalah tinggi muka air yang di beberapa stasiun pemantauan di Sungai Cileungsi yaitu : Dam Irigasi Cibongas, Jembatan WIKA dan Pondok Gede Permai.

Robust model for estimating pumping station characteristics and sewer flows from standard pumping station data

Flow data represent crucial input for reliable diagnostics of sewer functions and identification of potential problems such as unwanted inflow and infiltration. Flow estimates from pumping stations, which are an integral part of most separate sewer systems, might help in this regard. A robust model and an associated optimization procedure is proposed for estimating inflow to a pumping station using only registered water levels in the pump sump and power consumption. The model was successfully tested on one month of data from a single upstream station. The model is suitable for identification of pump capacity and volume thresholds for switching the pump on and off. These are parameters which are required for flow estimation during periods with high inflows or during periods with flow conditions triggering pump switching on and off at frequencies close to the temporal resolution of monitored data. The model is, however, sensitive within the transition states between emptying and filling to observation errors in volume and on inflow/outflow variability.

IDENTIFIKASI JENIS ANNELIDA PADA HABITAT SUNGAI JANGKOK KOTA MATARAM

Jangkok River is one of the lotic ecosystems in the city of Mataram. Based on previous studies it was concluded that this river has various types of biodiversity in it. The purpose of this study was to identify the types of Annelida found in the Jangkok River in Mataram City. This type of research is descriptive exploratory research with quantitative and qualitative approaches. This research was conducted on March 14, 2018. The research samples were river water taken at 3 stations namely upstream, middle and downstream using purposive sampling technique. Based on its existence, the Annelida type was found in downstream stations as many as 46 individuals, and 5 at the middle station, whereas it was not found at the upstream station. The type of Annelida found is the Olygochaeta class with Lumbricus terestis species and Tubifex sp. and the Hirudinae class with Hirudo medicinalis species.

Spatio-temporal variation of planktonic decapods along the leeward coast of the Fernando de Noronha archipelago, Brazil

Tropical island environments are considered hotspots due to their high diversity, endemism and ecological importance. However, reports that discuss the composition and ecology of planktonic decapods in these environments are still very few. In order to ascertain the composition, abundance and spatial-temporal distribution of planktonic decapods, zooplankton samples were taken by means of sub-surface hauls with a standard plankton net of 300 µm mesh size. Sampling was carried out at five stations in the nearshore leeward area of the Fernando de Noronha archipelago, in July and December 2013 and June and November 2014. A total of 22 decapod taxa were recorded, among which the most abundant were Brachyura (zoeae), Clibanarius sp., Caridea and Callianassidae. Characteristic annual distribution and temporal tendencies were observed for the larvae of the hermit crab Clibanarius sp. and for the larvae of burrowing shrimps (Callianassidae). Some taxa showed differences between sampling stations. In general, higher abundances were observed in the southern (downstream) stations of the island (Baía dos Golfinhos and Cacimba do Padre), and lower abundances in the northernmost (upstream) station (Porto de Santo Antônio), indicating the existence of larval retention in the nearshore coastal zone of this oceanic island ecosystem.