<p>Two decades ago the recruitment of YOY perch (<em>Perca fluviatilis</em>) started to decline along the Swedish east cost of the Baltic Sea. Factors that influence recruitment are e.g. eutrophication that causes habitat losses and overfishing of cod (<em>Gadus morhua</em>) which causes cascading effects in the food web. Filamentous cyanobacterial blooms are often toxic and has increased in the Baltic Sea and its coastal waters. The aim of this field study was to evaluate the effects of salinity and cyanobacterial exposure on fitness related parameters of young of the year (YOY) perch (<em>Perca Fluviatilis</em>) in a natural environment. Our study was performed in the Curonian Lagoon (Lithuania) in August 2009. The lagoon offers a temporary salinity gradient (wind induced influxes from the Baltic Sea) ranging from 7 psu in the north to 0 psu in the south. Submerged enclosures containing YOY perch were set up at three different locations along the salinity gradient in the Lagoon (referred to as North, Middle, South). The duration of the experiment was 21 or 27 days, depending on treatment. Measurements of perch condition were specific growth rate, somatic condition index (SCI) and whole fish lipid and protein content. Average chl <em>a</em> values for the three stations during the experimental time were: north 180 ± 70 µg/l chl <em>a</em>, middle 133 ± 36 µg/l chl <em>a</em> and south 180 ± 52 µg/l chl <em>a</em>. The North and the Middle stations experienced two different salinity influxes reaching a maximum salinity of 6.5 psu at the northern station. The duration of each saline influx was approximately 4-6 days. The saline water did not reach the Southern station at any time. Results show that perch from the southern station were in best condition in terms of specific growth rate and contents of total lipids. Compared to the South the perch condition declined to the Middle station and was lowest at the Northern station which experienced the highest degree of fluctuation in terms of salinity and cyanobacterial exposure. Examination of the abundance of the main food resource at the different stations revealed no statistical differences, which suggest that availability of food was not a factor in explaining the differences in growth.  The results possibly indicate that a changing environment with the potential synergistic negative effects of salinity and cyanobacteria has a higher negative impact on YOY perch condition compared to constantly high concentrations of cyanobacteria.</p>

Many rural communities in Manitoba use wastewater lagoons to treat sewage, but the nutrient removal process is not fully understood. This thesis’ purpose is to improve understanding of chemical and biological nutrient removal mechanisms of wastewater lagoon treatment and compare two different stabilization ponds – one aerated and one facultative. Samples were collected from stabilization ponds and analysed for a pond average. The facultative lagoon achieved overall ammonia-N removals similar to those of the aerated lagoon, and lower orthophosphate removals. Nitrogen appears to be removed by ammonia volatilization; and assimilation into biomass. Phosphorus appears to be removed by assimilation into biomass; and precipitation at alkaline pH. There appears to be nitrogen limiting conditions in the secondary cells of both stabilization systems based on nitrogen-phosphorus ratios. There does not appear to be any significant advantage between aerated or facultative lagoons; they will meet their ammonia limits, but will require additional phosphorus treatment. / October 2016

Little Lake Worth (LLW) (800 m x 200 m x 8« m) is an artificially deep, monomictic marine basin. Pigments and other water quality parameters (O2, pH, T, S, NO3 -. etc.) were utilized to characterize phototrophic communities and water quality. The water column is dominated by diatoms except in the hypolimnon during stratification events (late Summer) when strong anoxia and H2S favors abundant Chlorobium sulfur bacteria. Results indicate nitrate-enriched freshwater baseflow indicative of septic tank seepage during the wet season. This also appears to lead to the accumulation of concentrated organic matter in the sediment. LLW is a potential threat to the health of the ecosystem and the humans using it recreationally. More research is required to verify the effectiveness of restoration options. The spatial and temporal distribution of Chlorobium (phaeovibiroides tent.) and their Bacteriochlorophyll-e homologues is described and compared to similar studies. / by Keren Prize Bolter. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2010. Mode of access: World Wide Web.

Cette thèse se propose d’étudier l’évolution des milieux et des agrosystèmes en Languedoc durant les derniers dix millénaires grâce à l’étude des paléo-végétations. Tout en réévaluant les recherches anciennes, ce travail affine la résolution temporelle des mutations paysagères enregistrées et apporte une vision à l’échelle du Languedoc occidental, par l’étude des bassins versants de l’Aude et de l’Hérault. À partir de l’analyse palynologique de carottages effectués dans des zones lagunaires proches d’Agde et de Narbonne, ce travail met en exergue la coévolution entre milieux et agrosystèmes, tant sur le temps long que sur le temps de l’Homme, en analysant les particularités et les rapprochements entre dynamiques de ces deux bassins versants comme les stratégies d’exploitation du territoire développées par l’Homme, l’utilisation de ressources végétales spécifiques ainsi que les types et zones de cultures et de pâturages, au niveau des aires littorales, mais aussi dans l’arrière-pays languedocien. / This thesis studies the evolution of environments and agricultural systems in Languedoc during the last ten millennia through the paleo-vegetation. Reassessing old research, this work refines the temporal resolution of the landscape changes and provides vision at the western Languedoc scale, by the study of Aude and Hérault rivers watershed. From the pollen analyzes of cores drilled in lagoons close to Agde and Narbonne, this work highlights the coevolution between agricultural systems and environments, both long time and Man time, analyzing particularities and dynamic connections between these two watersheds like the territorial exploitation strategies developed by humans, the use of specific plant resources and the types and areas of crops and pastures, in coastal areas and in the Languedoc hinterland.

Two decades ago the recruitment of YOY perch (Perca fluviatilis) started to decline along the Swedish east cost of the Baltic Sea. Factors that influence recruitment are e.g. eutrophication that causes habitat losses and overfishing of cod (Gadus morhua) which causes cascading effects in the food web. Filamentous cyanobacterial blooms are often toxic and has increased in the Baltic Sea and its coastal waters. The aim of this field study was to evaluate the effects of salinity and cyanobacterial exposure on fitness related parameters of young of the year (YOY) perch (Perca Fluviatilis) in a natural environment. Our study was performed in the Curonian Lagoon (Lithuania) in August 2009. The lagoon offers a temporary salinity gradient (wind induced influxes from the Baltic Sea) ranging from 7 psu in the north to 0 psu in the south. Submerged enclosures containing YOY perch were set up at three different locations along the salinity gradient in the Lagoon (referred to as North, Middle, South). The duration of the experiment was 21 or 27 days, depending on treatment. Measurements of perch condition were specific growth rate, somatic condition index (SCI) and whole fish lipid and protein content. Average chl a values for the three stations during the experimental time were: north 180 ± 70 µg/l chl a, middle 133 ± 36 µg/l chl a and south 180 ± 52 µg/l chl a. The North and the Middle stations experienced two different salinity influxes reaching a maximum salinity of 6.5 psu at the northern station. The duration of each saline influx was approximately 4-6 days. The saline water did not reach the Southern station at any time. Results show that perch from the southern station were in best condition in terms of specific growth rate and contents of total lipids. Compared to the South the perch condition declined to the Middle station and was lowest at the Northern station which experienced the highest degree of fluctuation in terms of salinity and cyanobacterial exposure. Examination of the abundance of the main food resource at the different stations revealed no statistical differences, which suggest that availability of food was not a factor in explaining the differences in growth.  The results possibly indicate that a changing environment with the potential synergistic negative effects of salinity and cyanobacteria has a higher negative impact on YOY perch condition compared to constantly high concentrations of cyanobacteria.

According to earlier surveys, there were nine sound types in areas adjacent to the estuaries of nine major rivers in Taiwan, and the frequency range of the H-type sound was as high as 6 kHz. The producers of this sound type have not been defined yet. Sea catfish can make two kinds of sounds: stridulatory sound and drumming sound. The former is pulsed, broad-band and high-frequency, whereas the latter is harmonic, and low-frequency (less than 1 kHz). Spotted catfish (Arius maculates) is the most common demersal species in the west coast of Taiwan. The aims of the study were (1) to find out if H-type sound is presence in Cigu lagoon; (2) to describe the disturbance (hand-held) sounds emitted by A. maculates; (3) to find clues to support that the stridulatory sound of A. maculates is the H-type sound; (4) to find if there is sexual difference in the sounds of A. maculates; (5) to find the relationship between sound characteristics and intrinsic characters of the fish; (6) to define the reproductive season of A. maculates; (7) to find out if there is correlation between the spawning season of A. maculates in Cigu lagoon and presence of the high-frequency sounds in the lagoon. Bimonthly sound recordings were made in Cigu lagoon between February to December 2009. Pulsed, broad-band and high-frequency sounds were present in April, June, and August; number of sounds per minute was higher in August (mean: 52.9 sounds/ min). The sound were characterized by: sound duration: 160.6 ¡Ó 16.6 ms, dominant frequency: 2840 ¡Ó 867.3 Hz, pulse period 12.6 ¡Ó 0.45 ms, pulse duration: 6.0 ¡Ó 0.82 ms, inter-pulse-interval: 6.6 ¡Ó 0.84 ms. The stridulatory sounds of A. maculates are pulsed, broad-band and high-frequency - sound duration: 64.0 ¡Ó 16.74 ms, dominant frequency: 1251 ¡Ó 419.8 Hz, pulse period 7.7 ¡Ó 2.69 ms, pulse duration 5.3 ¡Ó 1.69 ms, inter-pulse-interval 2.4 ¡Ó 1.93 ms. Drumming sounds of A. maculates are harmonic, low frequency - sound duration: 58.5 ¡Ó 25.54 ms, dominant frequency: 442 ¡Ó 96.3 Hz fundamental frequency: 163 ¡Ó 30.98 Hz, pulse period: 6.3 ¡Ó 1.21 ms, pulse duration: 6.3 ¡Ó 1.19 ms. There was significant sexual difference in the stridulatory sound characters including pulse period, inter-pulse-interval, pulse number; females are higher than males in these parameters. There was significant sexual difference in the drumming sound (including dominant frequency) as well; males are higher than females in these parameter. Pulse period of the stridulatory sounds increased significantly with increasing standard body length. Pulse period and pulse duration of the drumming sounds both increased significantly with increasing standard body length, whereas dominant frequency and fundamental frequency both decreased significantly with size. GSI and oocyte diameters were higher in February, April, and June with a peak in April. Reproductive period was considered occurring from April to August (i.e. in spring and summer). This reproductive period coincides with the peak of vocalization. Result of ANOSIM indicates that, H-type sound is significant different from the stridulatory sound of A. maculates - they are in different groups. As the sound source might be at a distance from the recording site, energy in the high frequency range might decay with distance, whereas low frequency range might be cutoff as well. As A. maculates is the only soniferous spices in Cigu lagoon that can emit high-frequency sounds, possibility remains high that the high frequency sound, which resembles the H-type sound, in Cigu lagoon is actually produced by the spotted catfish despite of the difference in frequency-domain features of the sounds.

Jung Jeng Lake located in Mei Nong in south of Taiwan, is the origin of Mei Nong Hakka culture. Owing to stockbreeding hogs, cultivation and domestic wastewater in the upstream of Jiang Tz Liau River that finally flows into Jung Jeng Lake for years, the lake thus suffered extremely serious problem of eutrophication. In addition, the water hyacinth remain seeds in the lake and reproduce resulting in speeding up the lacustrine silt that would greatly shorten the life of Jung Jeng Lake. Using artificial lagoon and artificial floating island were found able to improve the water quality of lake. Therefore, we could sightseeing resource, historic site, and ecological resources of Mei Nong. This research applied the advantages of ecological engineering methods to restore the Jung Jeng Lake, and thus the southern Taiwan unique Hakka tourism can be presented.

A 3D numerical model ¡V COHERENS has been applied to construct a coupled hydrodynamic and ecological model for studying Tapeng Bay, which is a coastal lagoon situated in southwest of Taiwan. The simulations have been carried out to study the influences and their interacting mechanisms among the tidal currents, nutrients and micro planktons in the Lagoon. Model results have been compiled for calculating the nutrient fluxes and the primary productions in the Tapeng Bay. Tapeng Bay is a semi-enclosed coastal lagoon, which has only one tidal inlet for exchanging lagoon water with the coastal currents along the Kaoping coast on the narrow shelf in southwest of Taiwan. The study area is situated in the tropical climate zone where has sunshine through out the year except the rainy days concentrated in the summer season, which is influenced by the southwest monsoon. There are several drainage channels that collect the untreated domestic sewerage and wastewater discharged from the fish farms surround the lagoon. The discharges in these channels are usually low during the dry season. The solid contained in the water are mostly settled on the channel beds. During the raining season, high discharges due to the storm rainfalls re-suspend the sediments and carry into the lagoon. These sediments, which contain high concentrations of suspended solids and nutrients, cause the Bay water highly eutrophied. Therefore, the Bay is fully influenced by the seasonal variations. There are a lot of aquaculture, i.e. oyster farming and fish cage, in the Bay area since the water is calm and rich. But the balance between the nature and the anthropogenic disturbance is breaking. Besides the water level variation generated from the tidal inlet, the fresh water inflow from 3 major channels are included in the model to simulate their influences to the hydrodynamics and the density driven circulation due to changing salinities and temperatures from these inlets. Plankton, detritus, dissolved nutrients and dissolved oxygen is taking into account as the model variables for this marine eco-system. The plankton growth is mainly generated due to temperature, light intensity and nutrient level. Only the nitrogen cycle has been considered in the model by assuming there are enough supply of phosphate and silicate. Model runs have been carried out according to different seasonal situations of the boundary conditions. Furthermore, climates (heats, lights, winds, etc) are also included in the model to distinct seasonal characteristics. It is shown, from the model results, that the currents mainly dominate the distribution of nutrients in the Tapeng Bay. The nutrient level controls plankton growth. The nutrient sources are mainly coming from the coastal currents (through tidal inlet) in the wintertime, whereas the summer source was from the drainage channels due to the wash out by the high discharge rates. Beside these, dissolved oxygen concentrations in the Bay water are strongly influenced by the plankton growth rate, faster the photosynthesis higher the DO concentrations. The eutrophication levels of the Tapeng Bay water have been compiled using the plankton carbon level modeled at various situations. According to the Nixon standard (1995), Tapeng Bay has eutrophication through out the year. Mesotrophic condition can be observed during the wintertime, whereas the hypereutrophic level can be concluded during the raining season.

Σκοπός είναι η περιβαλλοντική χαρτογράφηση από δορυφορικές εικόνες Aster προκειμένου να χαρτογραφηθούν οι φυσικοί πόροι και οι καλύψεις Γης.Η ταξινόμηση της δορυφορικής εικόνας μας επέτρεψε να διακρίνουμε τις παρακάτω κατηγορίε : καλλιέργειες / ποώδη βλάστηση , δυο τύπους δάσους , αστική γη , υδάτινες επιφάνειες , σύννεφα και εντελώς γυμνό από βλάστηση έδαφος. / --

The local livelihood systems of Tam Giang Lagoon, Central Vietnam have shifted since the policy changes of 1986. Aquaculture has replaced capture fishing as the most important livelihood activity in the lagoon. Aquaculture is governed by both customary and legal access rights. The move from a centrally-planned (collectivization) economy to a market-oriented economy in conjunction with the development of the aquaculture sector has had significant impacts. This change has reduced the available lagoon areas for mobile-gear fishers, polarized different user-groups, and raised the issue of resource access inequity. The overarching objective of this thesis is to understand the complexity and influence of property rights on local livelihood systems; specifically: (1) to examine changes in resource access and various types of resource use in the lagoon; (2) to analyse the effects of aquaculture and changes in resource access on local livelihood systems; and (3) to assess the resilience of livelihood systems and identify the essential elements that contribute to resilience in livelihood systems. Qualitative and quantitative research methods were used for data collection. Sixty-five semi-structured interviews were conducted and fourteen households were selected for an additional in-depth livelihood analysis. Focus group discussions were one of the most important methods used for data collection. Fifteen formal focus groups and several informal discussions were organized. Both types of focus groups were used in conjunction with a number of participatory methods, such as seasonal calendar, participatory mapping, and well-being ranking. The field work was conducted over twenty-nine months between December, 2005 and April, 2008. The research examined the evolution of property rights and the complexity of resource access in Thuy Dien village. The research investigated seven types of resource use which are associated with “bundles of rights” and discussed the dynamics of property rights governed by both laws and customs. De jure and de facto rights were classified in different time periods by using Schlager and Ostrom’s framework. By applying a sustainable livelihood framework, the research presented overview of livelihood systems and discussed the influence of property rights on household livelihoods. Households in the village were classified into four groups: (1) earth pond, (2) net-enclosure; (3) mobile fishing; and (4) non-fishing households. Attention was paid to the disparity between these household types in term of livelihood strategies and opportunities for livelihood development. The research applied a resilience approach to the analysis of the local livelihood systems. Resilience is an inherent attribute of sustainable livelihood systems because it implies the flexibility and availability of options. If resilience is lost, livelihood systems may cross a threshold and shift to a different regime or alternative equilibrium. In Tam Giang Lagoon, a shift to a different regime seemed to have occurred over the last two decades.