The effects of road and bridge construction on the bank-root macrobenthic invertebrates of a Southern Nigerian stream

Assessment of aquatic macro-invertebrates communities and water quality parameters of River Zhob, Balochistan, Pakistan

Abstract Environmental stress caused by pollution is often assessed by diversity of macro-invertebrate species in specific aquatic habitat. To find out seasonal fluctuations in various macro-invertebrates communities and different water quality parameters of River Zhob, a research trial was conducted on River Zhob, Balochistan. Samples of macro-invertebrates and water were taken from four different stations of River Zhob. A total 18 taxa of various macro-invertebrates were identified from the area. Phylum Arthropoda constitute 94.8% of the total population followed by Mollusca (3.6%) and Annelida (1.4%). A large number of arthropods were belonged to order Diptera (1148), while the order Trichoptera was stood second with respect to macro-invertebrate´s number (441). The maximum numbers of macro-invertebrates were observed in the month of January. All physico-chemical parameters of River Zhob such as air temperature, water temp, pH, dissolved oxygen (DO) and total dissolved solids (TDS) were within the range, suitable for the healthy growth of macro-invertebrates. Diversified populations of various macro-invertebrates confirm good ecological condition of environment and water in the studied site especially ample concentration of DO in River. The documented data on macro-invertebrates in studied site will provide a baseline for future research.

Evaluation of stocking density for pond aquaculture with special reference to survival and production in Tiruchirapalli, Tamil Nadu

The present study was conducted to optimize the stocking density for pond fish culture. For this purpose, two different stoking densities, i.e. 18000 (T1) and 7600 per hectare (T2) were tested using earthen ponds of 0.25 ha size. Both ponds were stocked uniformly with 4 carp species, viz. Catla catla, Labeo rohita, Cirrhinus mrigala, and Cyprinus carpio in equal proportions and fed on commercial pellet feed (20% crude protein). The estimated gross production was found higher in pond T2 (4166 kg/ha) than that of T1 (4000 kg/ha). The T2 pond showed a net estimated additional yield of 187.76 kg/ha, which was 4.74% higher than that of T1 pond. A higher survival rate was observed in T2 (59.17%) than that of T1 (27.68%), which was statically significant. Further, the ADG (average daily growth) rate of fishes in T2 was 0.70 kg/ha/day higher than that of T1. The study revealed that there is an inverse relation between the stocking density of fishes and production rate. Considering the growth/production rate and survival in present study, a seed stocking density of 7600 per ha is recommended for farm pond aquaculture.

Catch per unit effort and some water quality parameters of Lake Kalgwai Jigawa state, Nigeria

This study investigated the catch per unit effort and water quality of Lake Kalgwai Jigawa state, Nigeria for the period of 10 month (July 2012‐June 2013). The man hours, gears used, and fish catches of the Lake was determined by assessing the fishermen operating on three major landing sites of the Lake, namely Marke (Site I), Dingare (Site II), and Kalgwai (Site III). Water samples from the landing sites were collected and analyzed. Concentration of fishers ranged from 41 (April) to 51 (September). The highest number of fishing hour was observed in August (64 hr), whereas the lowest was in March (49 hr). The average catch per fisher per day ranged from 107 kg/day (December) to 144 kg/day (August) during the study period. An average of 25 days was spent fishing in each month. The result also indicated similarities in the water qualities of all the three sampling sites per months. Based on the result gotten it was concluded that lake Kalgwa is not over fished and water quality are within recommended ranges for fish production.

Application of Aquatic Insects (Ephemeroptera, Plecoptera And Trichoptera) In Water Quality Assessment of Malaysian Headwater

The Ephemeroptera, Plecoptera and Trichoptera (EPT) community structure and the specific sensitivity of certain EPT genera were found to be influenced by water parameters in the rivers of Gunung Jerai Forest Reserve (GJFR) in the north of peninsular Malaysia. The scores of EPT taxa richness of >10 in all rivers indicated all rivers’ habitats were non-impacted, having good water quality coinciding with Class I and Class II of Malaysian water quality index (WQI) classification of potable water. The abundance of EPT was very high in Teroi River (9,661 individuals) but diversity was lower (22 genera) than Tupah River which was highly diverse (28 genera) but lower in abundance (4,263 individuals). The lowest abundance and moderate diversity was recorded from Batu Hampar River (25 genera). Baetis spp. and Thalerosphyrus spp., Neoperla spp. and Cheumatopsyche spp. were the most common genera found. Classification for all rivers using EPT taxa Richness Index and WQI gave different category of water quality, respectively. The WQI classified Tupah and Batu Hampar rivers into Class II and Teroi River (Class I) was two classes above the classification of the EPT taxa Richness Index.

Challenging issues of urban biodiversity related to ecohydrology

This paper aims to outline challenging issues of urban biodiversity in order to address yardsticks related to ecohydrology, and with a complementary approach to eutrophication impacts. The vision of environmental services, urbanization's consequences and management aspects of water governance are also depicted. Factors of river restoration, environmental tradeoffs and socio-cultural constrains are envisaged through concept questions towards emerging aspects that figure out methodological guides, strategic challenges for stakeholders and inter-disciplinary opportunities. Examples from case studies on restoration and management, from experiences and lessons learned, are enclosed, with brief discussions and literature citation.

Ecology and abundance of oligochaetes as indicators of organic pollution in an urban stream in southern Nigeria

A study of the aquatic oligochaetes of an organically polluted segment of an urban stream in Southern Nigeria was carried out to assess the ecological impact of abattoir effluent. Three stations 1, 2 and 3 were selected from upstream of the site receiving abattoir effluent, the impacted site and its down stream, respectively. Among the water quality variables, conductivity, dissolved oxygen, BODs, Nitrate-nitrogen, Phosphate-phosphorus and water hardness were significantly different (p < 0.05) among the stations. Orthogonal comparison using Duncan's multiple range test showed that station 2 (the impacted site) was the cause of the difference. A total of 14 species of oligochaetes were identified with 13 (92.8%) occurring in the impacted station. Tubifex, Dero limnosa and Nais communis were the dominant taxa, less frequent were Stylaria, Aelosoma and Lumbriculus variegatus (Muller). Pistina and Chaetogaster species were sporadically present. The density of the different taxonomic groups differed among the stations with the impacted station accounting for the greatest abundance and diversity of the organisms. The organic wastes from the abattoir not only altered the water chemistry but also stimulated the abundance of oligochaete worms.