The current distribution of signal and native crayfish in the Broadmead Brook, Wiltshire

Signal crayfish (Pacifastacus leniusculus) have existed in the upper reaches of Broadmead Brook in Wiltshire since 200 individuals were introduced at West Kington in 1981. The population has expanded upstream and downstream since this introduction, however, giving rise to concerns that it may potentially threaten the native crayfish population further downstream. Signal crayfish can act as a vector of crayfish plague - a disease caused by the fungus Aphanomyces astaci Schikora which results in almost complete mortality to the native, white-clawed crayfish Austropotamobius pallipes. The native crayfish in Broadmead Brook have not yet succumbed to crayfish plague and are currently free of the disease. However, as signal crayfish appear to out-compete the native species, the native population could still be under threat. In this article, we highlight the findings of previous crayfish surveys on Broadmead Brook and describe work undertaken in summer 2001 to map the current distribution of native and signal crayfish. Finally, options for controlling the spread of signal crayfish are discussed.

Fish and fisheries in the Sesan River Basin: catchment baseline, fisheries section

The present report was prepared for the Water and Food Challenge Program project “Optimizing the management of a cascade of reservoirs at the catchment level” (MK3). It constitutes the baseline assessment of fish and fisheries in the Sesan River Basin. The objective of the MK3 project is to contribute knowledge and recommendations so that cascades of reservoirs corresponding to hydropower dams in the Mekong Basin are managed in ways that are more fair and equitable for all water users. This project seeks to understand at the catchment scale the cumulative upstream and downstream consequences of management decisions taken for multiple reservoirs. Revised rules for water storage infrastructure management will in particular take into account fisheries and agricultural potential as well as hydropower gen

Variation in movement patterns of red drum (Sciaenops ocellatus) inferred from conventional tagging and ultrasonic telemetry

We used 25 years of conventional tagging data (n= 6173 recoveries) and 3 years of ultrasonic telemetry data (n=105 transmitters deployed) to examine movement rates and directional preferences of four age classes of red drum (Sciaenops ocellatus) in estuarine and coastal waters of North Carolina. Movement rates of conventionally tagged red drum were dependent on the age, region, and season of tagging. Age-1 and age-2 red drum tagged along the coast generally moved along the coast, whereas fish tagged in oligohaline waters far from the coast were primarily recovered in coastal regions in fall months. Adult (age-4+) red drum moved from overwintering grounds on the continental shelf through inlets into Pamlico Sound in spring and summer months and departed in fall. Few tagged red drum were recovered in adjacent states (0.6% of all recoveries); however, some adult red drum migrated seasonally from overwintering grounds in coastal North Carolina northward to Virginia in spring, returning in fall. Age-2 transmitter-tracked red drum displayed seasonal emigration from a small tributary, but upstream and downstream movements within the tributary were correlated with fluctuating salinity regimes and not season. Large-scale conventional tagging and ultrasonic telemetry programs can provide valuable insights into the complex movement patterns of estuarine fish.

River Dart Weir and fish pass survey 1992

This is the River Dart, Weir and Fish Pass Survey 1992 report produced by the National Rivers Authority. It goes through the general condition of Weirs and fish passes to determine the extent of problems associated with the upstream and downstream migration of salmonids. It considers solutions where problems exist and investigates the exact use of the resource. It looks at the following Weirs: Totnes, Staverton, Hood, Kilbury, Buckfast, Holne, Mardle (River Mardle), Holybrook (Holybrook), Jordan (West Webburn), Swincombe Intake (River Swincombe), Blackbrook, West Dart, Cowsic (Devonport Leat), Kingfisher Press (Bidwell Brook) and Bagpark (East Webburn). It also contains location maps of the weirs and individual fact sheets along detailed pictures and diagrams.

Study on some biological and feeding factors of spined loach Cobitis taenia from the Babolrud, Talar and Siahrud Rivers

Spined loach, Cobitis taenia, is a predominant fish in the river systems of the southern Caspian Sea basin. Although there is evidence of the geographical divergence of this taxon, but no information is available on morphological differences within the species populations. This study was designed to evaluate some biological factors including; morphometric and meristic characters, length-weight, age-growth, condition factor, diet, reproduction, variation and differentiation, in the Babolrud, Talar and Siahrud Rivers in south of the Caspian Sea basin. Age, sex ratio, fecundity, ova diameter and gonadosomatic index were estimated. Also, regression analyses was tested the relation between fecundity and fish length, weight, gonad weight, and also age. Totally 858 fish of which 721 were matures, were collected from these rivers by electrofishing. 37 morphometric characters, 9 meristic characters and 78 truss network system characters were estimated. Resulats of DFA analysis based on data of morphometric and meristic showd that these populations are highly (94.5%) varios from each other. In discriminate function analysis, the proportion of individuals correctly classified into their original groups was 61%, 65.4% and 86.5% for upstream and downstream, respectively. Clustering based on Euclidean distances among groups of centroids using an UPGMA and also principal component analysis’ results for morphometric data indicated that these populations from these three rivers were clearly distinct from each other. Regression equations between length and weight in these three populations were significantly different from Folton factor (b=3), that showed the fish has a negative Alometric growth process. Condition factor was estimated between 0.8912 to 1.2736 and 0.8131 to 1.4489 for males and females, respectively. Sex ratio (female: male) in these populations was 1.2816:1. The difference between the number of females and males was significant and females were more than males. The female and male specimens reach maturity by Tl more than 40 and 30 mm and at the age of 2+ and 1+, respectively. The mean of ova diameter was 0.5824±0.2882. The spawning took place from May to late July, at the water temperature from 18.7 to 24.0°C. The GSI values average at the beginning of the reproduction period was about 9%, with ranged from 2 to 26% in ripe mature females. The absolute and relative fecundity were 2109±792 and 579±208 respectively. The absolute fecundity was significantly related to body weight and gonads weight. Based on the pattern of gonado-somatic index, it was concluded that this fish has prolong active reproductive period, which is a type of adaptation by short-lived small fishes to environmental conditions. The macroscopic and histological results showed that the female and male have 5 and 4 stages in their maturation process, respectively. The RLG index was about 0.4732, which showed the fish is a carnivorous species. Significant difference was observed between fishes with different length and diet. The main foods of the fish were Trichoptera, Chironomidae larvae and Ephemeroptera which were their prefered food as well, however it was estimated that the food selection and diet are affected by environmental conditions.

Effects of cage fish culture on water quality and selected biological communities in northern Lake Victoria, Uganda

Growing of fish in cages is currently practiced in Uganda and was first introduced in northern Lake Victoria in 2010. An environment monitoring study was undertaken at Source of the Nile, a private cage fish farm, in Napoleon gulf, northern Lake Victoria. In-situ measurements of key environmental (temperature, dissolved oxygen, pH and conductivity) and biological (algae, zooplankton, macro-benthos) variables were made at three transects: Transect 1- the site with fish cages (WC); transect 2- upstream of the fish cages (USC-control) and Transect 3- downstream of the cages (DSC). Upstream and Downstream sites were located approximately 1.0 km from the fish cages. Environment parameters varied spatially and temporally but were generally within safe ranges for freshwater habitats. Higher concentrations of SRP (0.015-0.112 Mg/L) occurred at USC during February, September and at DSC in November; NO2-N (0.217- 0.042 mg/L) at USC and DSC in February and November; NH4-N (0.0054- 0.065 Mg/L) at WC and DSC in February, May and November. Algal bio-volumes were significantly higher at WC (F (2,780)=4.619; P=0.010). Zooplankton species numbers were consistently lower at WC with a significant difference compared to the control site (P=0.032). Macro-benthos abundance was consistently higher at the site with cages where mollusks and low-oxygen and pollution-tolerant chironomids were the dominant group. Higher algal biomass, concentration of low-oxygen/pollution-tolerant macro-benthos and depressed zooplankton diversity at WC suggested impacts from the fish cages on aquatic biota.

Monthly patterns in physico-chemical conditions and fish catch in the immediate vicinity of the Bujagali hydropower construction site 29th September - 28th October 2007

The specific objectives were to: WATER QUALITY 1. To measure the water physical variables as indicators of environmental conditions in the upstream and downstream transects of Kalange (1) and Buyala (2), respectively, 2. To determine the concentrations of total suspended solids as a major constituent likely to be released into the waters at any time during the construction activities, by comparing the concentrations at the two transects. FISH CATCH 1. To follow up trends in fish catch as construction activity progresses, and to precision of the estimate; 2. To estimate the prevailing fish catch rates, total fish catches and the total value of the fish catch to the local fishers at the two transects.

To pave or not to pave: A social landscape analysis of land use decision-making in the towns of the lamprey watershed

Population pressure in coastal New Hampshire challenges land use decision-making and threatens the ecological health and functioning of Great Bay, an estuary designated as both a NOAA National Estuarine Research Reserve and an EPA National Estuary Program site. Regional population in the seacoast has quadrupled in four decades resulting in sprawl, increased impervious surface cover and larger lot rural development (Zankel, et.al., 2006). All of Great Bay’s contributing watersheds face these challenges, resulting in calls for strategies addressing growth, development and land use planning. The communities within the Lamprey River watershed comprise this case study. Do these towns communicate upstream and downstream when making land use decisions? Are cumulative effects considered while debating development? Do town land use groups consider the Bay or the coasts in their decision-making? This presentation, a follow-up from the TCS 2008 conference and a completed dissertation, will discuss a novel social science approach to analyze and understand the social landscape of land use decision-making in the towns of the Lamprey River watershed. The methods include semi-structured interviews with GIS based maps in a grounded theory analytical strategy. The discussion will include key findings, opportunities and challenges in moving towards a watershed approach for land use planning. This presentation reviews the results of the case study and developed methodology, which can be used in watersheds elsewhere to map out the potential for moving towns towards EBM and watershed-scaled, land use planning. (PDF contains 4 pages)

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)

Aquatic ecology monitoring: water quality, fish, fish catch, sanitation and disease vectors: monitoring no. 10 and reservoir baseline, 23rd – 30th April 2012

The results reported on were from a monitoring survey No. 10 undertaken between 23 rd and 29th April 2012 during construction period of the Bujagali Hydropower Project (BHPP). Two pre-construction, baseline surveys in April 2000 and April 2006 were conducted and so far, during construction phase of the project, nine monitoring surveys have been undertaken i.e. in September 2007, April 2008, April 2009, October 2009, April 2010, September 2010, April 2011, September 2011and the present one, in April 2012. 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) During this survey, baseline assessment of the above mentioned studies was conducted in the reservoir behind the dam, including studies on algae, zooplankton and benthic macroinvertebrates which had been restrained since April 2008. The findings of baseline assessment of the reservoir are also contained in this report and are compared with those obtained from Transect 1(Upstream) and Transect 2 (Downstream).

Aquatic ecology monitoring: water quality, fish, fish catch, sanitation and disease vectors: monitoring No.7, 4-7th September 2010

The results reported on were from a monitoring survey No.7 undertaken between 4 th and 7th September 2010 during construction period of the Bujagali Hydropower Project (BHPP). Two pre-construction, baseline surveys in April 2000 and April 2006 were conducted and so far, during construction phase of the project, six monitoring surveys have been undertaken i.e. in September 2007, April 2008, April 2009, October 2009, April 2010 and the present one, in September 2010. Since 2009 biannual monitoring surveys have been conducted at an upstream and a downstream transect of the BHPP with emphasis on the following aspects: I. 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.12, 25th-30th April 2013

Bujagali hydropower dam construction is now completed and a reservoir behind the dam has been created, extending all the way up to Kalange-Makwanzi, an upstream transects. During the 10th monitoring survey-April 2012, a third transect was established in the mid of the reservoir where it runs up to 30 m deep and sampled similarly as at the two original sampling transects, Kalange-Makwanzi and Buyala-Kikubamutwe for comparative purposes. This monitoring survey No. 12 undertaken between 25th and 30th April 2013 is the third one to be conducted after completion of construction of Bujagali Hydropower Dam. Two pre-construction baseline surveys in April 2000 and April 2006 were conducted and during construction phase, eight monitoring surveys (September 2007, April 2008, April 2009, October 2009, April 2010, September 2010, April 2011, September 2011) were conducted. 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). In the post-construction monitoring surveys, the assessments of algae, zooplankton and benthic macro-invertebrates which had been restrained since April 2008 were also included.

Aquatic ecology monitoring: water quality, fish, fish catch and parasites: monitoring no.4, 3rd-7th April 2009

The survey covered by this report was undertaken between 3rd and 7th April 2009 as a follow-up on the during construction surveys. Two pre-construction baseline surveys were undertaken in April 2000 and April 2006. During the construction phase which started in 2007, three surveys including the current one have been undertaken i.e. in September 2007, April 2008 and the present one, in April 2009. Unlike in all previous surveys in which monitoring was conducted at one transect upstream and three downstream transects, in the current survey, two transects, one upstream and the other,downstream of the BHPP were sampled 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.9, 9th – 12th September 2011

The results reported on were from a monitoring survey No. 9 undertaken between 9th and 12th September 2011 during construction period of the Bujagali Hydropower Project (BHPP). Two pre-construction, baseline surveys in April 2000 and April 2006 were conducted and so far, during construction phase of the project, eight monitoring surveys have been undertaken i.e. in September 2007, April 2008, April 2009, October 2009, April 2010, September 2010, April 2011 and the present one, in September 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)in addition to the above mentioned studies, a soil pH survey was undertaken on 15th October 2011 in the area behind the reservoir whose filling started a week earlier. The findings of pH status in the catchment of the dam are also contained in this report.