Aquatic ecology monitoring: water quality, fish, fish catch, sanitation and disease vectors: monitoring No. 5, 6th-9th October 2009

The survey covered by this report was undertaken between 6 th and 9th October 2009 as a follow-up on the during construction surveys of the Bujagali Hydropwer Project (BHPP). In addition to two pre-construction baseline surveys in April 2000 and April 2006, four monitoring surveys have so far been undertaken i.e. in September 2007, April 2008, April 2009 and the present one, in October 2009. The 2009 biannual monitoring surveys were conducted at an upstream and a downstream transect of the BHPP with emphasis on the following aspects: 1. water quality determinants 2. biology and ecology of fishes and food webs 3. fish stock and fish catch including economic aspects of catch and 4. sanitation/vector studies (bilharzias and river blindness)

Aquatic ecology monitoring: water quality, fish, fish catch, sanitation and disease vectors: monitoring no. 8, 6– 10th April 2011

The result reported were from a monitoring survey no.8 undertaken between 6th and 10th April 2011 during construction period of the Bujagali Hydropwer Project (BHPP). Two pre-construction, baseline surveys in April 2000 and April 2006 were conducted and so far,durin construction phase of the project, seven monitoring surveys have been undertaken i.e. in September 2007, April 2008, April 2009,October 2009, April 2010, September 2010 and the present one, in April 2011. Since 2009 biannual monitoring surveys have been conducted at an upstream and a downstream transect of the BHPP with emphasis on the following aspects: Water quality determinants Biology and ecology of fishes and food webs Fish stock and fish catch including economic aspects of catch and Sanitation/vector studies (bilharzias and river blindness)

A baseline fish survey and water quality assessment of Butiaba-Wanseko area on Lake Albert

This report gives the baseline information specifically on water quality (physical/chemical, nutrient and phytoplankton biomass status) of the open part of the lake, a river flowing into the lake and a lagoon, within Butiaba-Wanseko area. Oil and gas exploration in the Albertine Graben are on-going activities by Tullow Oil Plc, and Heritage Oil and Gas (Heritage). Part of the activities involve 2-D TZ seismic surveys in exploration area Block 2 (Butiaba-Wanseko area) in Buliisa District. A study of the transition zone (basically along the shoreline was undertaken by National Fisheries Resources Research Institute (NaFIRRI) on behalf of Environmental Assessment Consult Ltd (EACL) during September 2007. A major objective of the study was to carry out a baseline survey of the fisheries and water quality of the lake shore between Wanseko and Butiaba prior to the proposed 2-D Seisimic investigation.

Restricted water exchange in the Negombo Lagoon on the west coast of Sri Lanka

Salinity, fresh water and sea level data from the Negombo Lagoon with respect to oceanic sea level and salinity data were considered. The open ocean spring tidal range was 0.57 m, whereas the neap tidal range was 0.10 m. In lagoon, the corresponding spring tidal range was 0.13 m and neap tidal range is 0.05 m. The lagoon tide was strongly choked because of the restricted inlet channel, through which only a limited water exchange could take place over a tidal cycle. Mean water exchange and the residence times for variable fresh water supplies were calculated. These calculations were based on fortnightly measurements of salinity and river discharges in 1993. During this year, salinity varied from 30-5‰ depending on the river inputs which were 20-225 m³ sˉ¹. Corresponding residence times varied from 11-2 days and the tide is dominated the exchange during low discharges of freshwater.

Hydrobiological status of a lesser Himalayan river

It is generally observed that a variety of physical and chemical variables have considerable impact on the biological life in a mountain river which include plankton, benthic algae, benthic invertebrate and finally the fishery resources. They are often subjected to extreme hydrological disturbances particularly during rainy seasons when increased volume of water create 'Wash Off' situation for existing fauna and flora. A case study of a lesser Himalayan river - the Gaula, which drains the south-central part of Kumaon region in Uttaranchal is presented here. Since this river does not get snow-melt water, it mainly depends on steady flow of the groundwater round the year. The climate of the area is characterized with long winters, short summer and good amount of rain during monsoon months. The infiltrated groundwater which seeps into the surface soil layers during monsoon seasons is the chief source of discharge of water during winter and summer season

Phytoplankton communities of a floodplain lake of the Brahmaputra River basin, Upper Assam

Phytoplankton (52 species; Bacillariophyceae>Chlorophyceae>Cyanophyceae> Euglenophyceae=Dinophyceae) of Samuajan beel, a tropical floodplain lake, registered identical mean annual richness (30+4 species) in littoral and limnetic regions and depicted 33.3-77.2% and 31.4-81.1% community similarities respectively. Their abundance ranged between 137+54 n/l in littoral (Bacillariophyceae>Chlorophyceae) and 122 ± 45 n/l (Chlorophyceae>Bacillariophyceae) in limnetic communities, comprised about 46% of net plankton and indicated winter peaks. This study depicted moderate species diversity, high evenness and low dominance of phytoplankton; species diversity showed significant direct correlation with richness and evenness and an inverse relationship with dominance. Phytoplankton showed significant positive relationship with transparency and silicate and negative with water temperature, rainfall, chloride and nitrate. Multiple regression revealed that ten abiotic factors accounted for >80-98% of density variations of phytoplankton and the dominant groups. ANOVA depicted trends of significance in abundance of the biotic communities analysed.

Benthic macro-biota in Gaula River - Kumaon Himalaya

The density of benthic macro-biota in number over weight of biomass at three sampling stations was 29 units m²/0.614 g m² to 171 units m²/11.346 m² at Station I; 22 units m²/0.410 g m² to 155 units m²/8.717 m² at Station II; 15 units m² 10.321 g m² to 122 units m²/6.793 g m² at Station III. The Caddis fly larvae were the most dominant component and contributed 52.41% in the macro-biota. These animals were abundant in Gaula River when benthic algae were abundant; water is well oxygenated, alkaline and contains sufficient nutrients but observed to be less abundant during high velocity of water, high river depth and higher turbid waters.

Early developmental stages of two Secutor species (Family: Leiognathidae) collected from the Bak-khali river estuary of the Bay of Bengal, Bangladesh

Early developmental stages of two Secutor species, Secutor insidiator (Bloch) (11.9-36.0 mm standard length, SL) and Secutor ruconius (Hamilton-Buchanan) (14.0-33.0 mm SL) collected by ichthyoplankton net from the Bak-khali river estuary of the Bay of Bengal, Cox's Bazar, Bangladesh are described and illustrated. All of the fins with supporting spines and rays were present in the smallest collected sizes of both species. With growth of the specimens, significant changes in melanophore patterns were found. S. insidiator is similar to S. ruconius in having upward protracting mouth parts and body colouration, but can be distinguished easily by its more elongate body shape (body depth 38-47% of SL compared with 46-52% of SL in Secutor ruconius). Both the species occurred round the year from August 1998 to July 1999. The surface water temperature and salinity during the study period varied from 22.0-32) C and 10-37 ppt respectively.

Eco-biology of Mastacembelus pancalus (Ham.) and their distribution in different water bodies

The eco-biological of the spiny eel, Mastacembelus pailcalus in the river Padma, adjacent flood plains and ponds were influenced by various physico-chemical factors such as water temperature, water transparency, pH, dissolved oxygen, free carbon dioxide and alkalinity. Flood plain areas are the best habitat for the M. pancalus with maximum abundance.

Microhabitat breadth of fish community along the Vamanapuram River, south Kerala

The microhabitat breadth of Vamanapuram River fish community was studied in detail. The microhabitat variables selected were relative depth, focal point velocity, water column depth, mean water velocity and substrate. Puntius filamentosus had the highest breadth in three dimensions in both stream and river habitats showing a generalistic mode of resource utilization. Garra mullya, Labeo dero and Glossogobius giuris are specialists in the usage of microhabitat variables in the stream habitat while these are G. mullya, Etroplus maculatus and Aplocheilus lineatus in river habitat. Danio aequipinnatus showed extreme variations along focal point velocity variable in both habitats indicating an. opportunistic behaviour.

Benthic diversity of River Gomti in relation to the prevailing environmental conditions in Lucknow

To evaluate the benthic diversity of River Gomti in relation to the prevailing environmental conditions, four stations, viz., Maa Chandrika Devi, Daliganj, Ambedkar Park and Aquaduct, were identified from upstream to downstream along the course of the river in Lucknow. Dissolved oxygen was low on many occasions at all the stations except Maa Chandrika Devi and chemical oxygen demand values were high. There was a gradual increase in mean nitrite and phosphate values from up to downstream. Benthic fauna was dominated by oligochaetes and chironomus larvae. Other groups reported were leeches, nematodes, sponges, crustaceans, pelycypodes, gastropods and fish fry. Population density was exceptionally high at Daliganj (20,135 m sub(-1) ) followed by Ambedkar Park (5,199 m sub(-1)) and Aquaduct (3,287 m sub(-1)), and low at Maa Chandrika Devi (264 m sub(-1)). Oligochaete genera common at all the four stations were Lumbricillus, Limnodrillus, Branchiura, Chaetogaster, Nais and Tubifex. Odonates were reported only from Maa Chandrika Devi while sponges were encountered at Daliganj and Aquaduct. On some occasions, fish fry were also found at Ambedkar Park and Aquaduct. Seasonally, maxima for population density were observed during pre-monsoon and minima during monsoon. The organic pollution indicator benthic species reported were tubificids, chironomids, culicoid larvae, Lamellidens sp., Corbicula sp., Lymnaea sp. and leech. Branchiurans, Tubifex sp. and Chironomus larvae were reported at all the stations. Filthy condition with foul smell throughout the length of the river coupled with poor water quality and appearance of indicator organisms at all the stations indicate that the river is under severe pollution stress due to anthropogenic discharges and it has reached an alarming stage.

Effect of thermal pollution on the hydrological parameters of River Jhelum (J & K)

The Buniyar hydroelectric project and the lower Jhelum Barrier at Gantamulla constructed across river Jhelum are in operation from several years. The two power stations have changed the hydrological features of the area where dam is situated. Therefore, the impact of hydroelectric projects on fishery resources of river Jhelum is a matter of great concern. The treated water from the power house is released through turbines, having cooling effect on them. The change in the hydrological parameters such as increase in temperature, depletion of oxygen etc. might have brought fishes under stress which is the main cause in decreased population of finfishes from site to site. The golden mahseer, Tor putitora which was once an abundant species in river Jhelum has disappeared due to human intervention. The prevailing water quality around hydroelectric projects is unsuitable for finfishes of river Jhelum.

Assessment of pelagic primary and secondary production in Sefidrud River estuary

Sefid-Rood River Estuary (SRE) is the most important riverine ecosystem in the south Caspian Sea along the Iranian coast lines. The aim of this study was to examine spatial and temporal variability in Phytoplankton and Zooplankton abundance and diversity in SRE. Variability of Chlorophyll a and inorganic nutrient concentration were determined during a year (November 2004– October 2005) in five sampling stations. Primary and secondry production were determined during a year. Total chlorophyll a concentration during the investigation ranged between zero to 22.8 μgl-1 and the highest levels were consistently recorded during summer and the lowest during winter with a annual mean concentration 4.48 μgl-1. Nutrient concentration was seasonally related to river flow with annual mean concentration: NO2 0.05±0.2 mgl-1, NO3 1.13±0.57 mgl-1, NH4 0.51±0.66 mgl-1, total phosphate 0.13±0.1mgl-1 and SiO2 5.68±1.91 mgl-1. Bacillariophytes, Cyanophytes, Chlorophytes, Pyrophytes and Euglenophytes were the dominant phytoplankton groups in this shallow and turbid estuary. The diversity and abundance of phytoplankton had a seasonal pattern while Diatomas and Chrysophytes were dominant throughout the year but Cyanophytes observed only during the summer. Zooplankton community structure was dominated by copepods which 68% of the total zooplankton. In the winter and summer seasons two increased in the number of zooplankton community and usually toward the sea had occurred. Zooplankton also showed a significant spatial and temporal variation. The high turbidity and temperature prime characteristics of SRE seem to be determining factors acting directly on phytoplankton and zooplankton temporal variability and nutrient fluctuations. Everywhere in this estuary nutrients appeared to be in excess of algal requirement and did not influence a phytoplankton and zooplankton composition. Also there was a positive correlation between chlorophyll a and temperature and a negative one with DIN and TP. Primary production determined in this estuary by dark and light butter method and G.P.P. 38.27±34.12 mgcm-2h-1 and N,PP 201.6±289.9 mgcm-2d-1. secondry production determined 15/128 mgc/m3/year. Everywhere in this estuary nutrients appeared to be in excess to algal requirement and did not influence in Chl. a and primary production. The most important factor influence on Chl. a was water temperature.

Temporal and spatial distribution of phytoplankton with emphasis on Skeletonema costatum in the Mathamuhuri river – estuary (Chakaria mangrove ecosystem), Bangladesh

A total of 91 species under 44 genera were identified among the phytoplankton community during the course of one year's investigation between May 1982 and April 1983. Bacillariophyta was the most dominant group with 72 specie, Chlorophyta 11 spp, Cyanophyta 6 spp and Pyrrophyta was represented by 2 species. The yearly percentage composition of 4 groups of phytoplankton in order of abundance were Bacillariophyta 50.77%, Cyanophyta 47.70%, Chlorophyta 1.5% and Pyrrophyta 0.02%. The highest densities of phytoplankton were recorded in monsoon months (June-July) with a peak in July (31550 cells/l) and the minimum in February (770 cells/1). Higher concentration of phytoplankton was recorded at station 2, nearer to the Chakaria Sundarbans (mangroves), but abundance of phytoplankton showed no significant difference in the two stations (Mann Whitney U test, P=0.64, Z=-0.642, U=64). Phytoplankton population in this area were positively correlated with rainfall (r=0.655, P=<0.5, df.22) and water temperature (r=0.523, P=<0.05). Skeletonema costatum was the dominant member of phytoplankton and occupied 35.23% of the annual population and occurred throughout the period of study except in September and January. Its abundance was recorded during the monsoon months (April- July) with a maximum density (24185 cells/l) in July. No significant correlation was found between abundance of S. costatum and the hydro-meteorological parameters recorded in the Chakaria mangrove area.

Management of water hyacinth, Eichhornia crassipes, in Lake Victoria Basin

Water hyacinth is a free-floating waterweed native to the Amazon River Basin in South America. In its native range, water hyacinth is not an environmental problem, although the weed is one of the most invasive alien plants in freshwater environments. Water hyacinth has the potential to become invasive through fast vegetative reproduction and rapid growth to accumulate huge biomass and extensive cover in freshwater environments. Over the last 150 years water hyacinth has invaded most countries in the tropics and sub-tropics, introduced by man, mainly for ornamental purposes. Such introductions led to the infestation of most freshwater-ways in the southern United States of America, parts of Australia, the pacific islands, and most countries in Asia and Africa. The extensive tightly packed mats of water hyacinth are often associated with devastating socio-economic and environmental impacts. Invasion by the weed has, therefore, often generated urgent costly problems associated with the weed biomass and its management. A classic example of such problems was triggered by the invasion and proliferation of water hyacinth in the Lake Victoria Basin during the 1980s (Freilink 1989, Taylor 1993, Twongo et al., 1995). The weed infestation marked the beginning of a decade of intensive and systematic campaign by the three riparian states (Kenya, Tanzania and Uganda) to bring weed proliferation under control. The discussions in this Chapter span over ten years of dealing with the challenges paused by the imperative to manage infestations of water hyacinth in the Lake Victoria Basin. The challenges included the need to understand the dynamics of water hyacinth infestation; its distribution, proliferation and impact modalities; and the development and implementation of appropriate weed control strategies and options. Most specific examples were taken from the Ugandan experience (NARO, 2002).