Eliassen, Lars Moland

Counting and classifying fish moving upstream in rivers to spawn is a useful way of monitoring the population of different species. Today, there exist some commercial solutions, along with some research that addresses the area. Case-based reasoning is a process that can be used to solve new problems based on previous problems. This thesis studies the possibilities of combining image processing techniques and case-based reasoning to classify species of fish which are similar to each other in both...

Gärde, Jenny

Tjörn is a cluster of islands, located in Västra Götaland’s county, on the west coast of Sweden. A fishing industry called Kädesholmen Seafood AB is located at Kädesholmen, one of the larger islands of Tjörn. The industry produces different types of fish preserves. The resulting waste water is polluted with mostly nutrients and organic matter in high concentrations. In lack of other treatment alternatives, the waste water is collected and transported to Trollhättan for biological degradation. Sw...

Kasornchandra, Jiraporn

Graduation date: 1992

Hasnain, Sarah

Habitat temperature is a major determinant of performance and activity in fish. I examined the relationships between thermal response metrics describing growth (optimal growth temperature [OGT] and final temperature preferendum [FTP]), survival (upper incipient lethal temperature [UILT] and critical thermal maximum [CTMax]), and reproduction (optimum spawning [OS] and optimum egg development temperature [OE]) for 173 North American freshwater fish species. All metrics were highly correlated and...

Yazgan Tavsanoglu, Ulku Nihan

In this study, the factors influencing zooplankton community structure in Turkish shallow lakes were elucidated with four main approaches: (i) space-for-time substitution for shallow lakes using snap-shot sampling in 31 lakes along a latitudinal gradient / (ii) in-situ mesocosm experiments in eleven lakes along a latitudinal gradient using three sets of artificial plants systems / (iii)&lsquo / Habitat Choice&rsquo / laboratory experiments mimicking a &lsquo / shallow littoral&rsquo / zone with ...

Tengelsen, Leslie A.

Hatchery-reared salmonid fish routinely encounter stress due to handling, barging, tagging, and overcrowding. It has been demonstrated that there exists a direct correlation between stress and transient immune suppression which can last for many days in fish. Epizootic viral infections routinely appear in hatcheries and can have a devastating effect on the fish population. The major viral pathogens in salmon and trout are the fish rhabdovirus, infectious hematopoietic necrosis virus (IHNV), and ...

Togunde, Oluranti Paul

This thesis describes the development and application of solid phase microextraction (SPME) as a sample preparation technique for in vivo determination of pharmaceutical residues in fish tissue and wastewater. The occurrence, distribution and fate of pharmaceuticals in the environment are a subject of concern across the globe due to the impact they may have on human life and aquatic organisms. To address this challenge from an analytical perspective, a simplified and reliable analytical methodol...

Bai, Ziwei

The presence of off-flavor compounds in fish represents one of the significant economic problems encountered in aquaculture. These off-flavor compounds are due to the absorption of substances produced by microorganisms. Currently, a number of strategies have been employed to prevent or limit the growth of these microorganisms in recirculating aquaculture system. Therefore, it is important to evaluate the effectiveness of these strategies by monitoring the concentrations of off-flavor compounds i...

Cameron, William A.

Ecologists have studied the responses of pelagic ecosystems to varying levels of nutrient loading and fish predation on many different scales ranging from small experimental enclosures to whole lake systems. There are recurring patterns of response to these two variables, which are generally predictable on the basis of biogeographic, behavioral, morphological, and physioenvironmental ecological principles applied to the life histories stategies of individual species. This study focused on the ch...

Cho, Young Mi

Accumulated genetic and epigenetic abnormalities contribute to the development of colon cancer. We have shown that a combination of fish oil (containing decosahexaenoic acid, DHA, 22:6 n-3) and pectin (fermented to butyrate by colonic microflora) is protective against colon carcinogenesis in part by regulating the expression of genes involved in apoptosis, leading to apoptosis induction. To determine how FO/P enhances apoptosis, we measured the expression of genes involved in apoptosis. We per...

Abrahamson, Alexandra

Induction of the cytochrome P450(CYP)1A protein and the connected increase in 7-ethoxyresorufin O-deethylase (EROD) activity are common biomarkers in fish. Enhanced activity of this protein signals exposure to Ah-receptor agonists such as chlorinated dioxins, co-planar polychlorinated biphenyls (PCBs) and certain polycyclic aromatic hydrocarbons (PAHs). The EROD biomarker is commonly analyzed in liver microsomes. However, the gill is directly exposed to waterborne pollutants, and in this thesis ...

Andersson, Carin

Many chemicals present in the aquatic environment can interfere with physiological functions in fish. Exposure to chemicals can be revealed by the use of biomarkers. Induction of 7-ethoxyresorufin O-deethylase (EROD) activity is a commonly used biomarker for exposure to CYP1A inducers such as dioxins and polyaromatic hyrdrocarbons. Vitellogenin is a frequently used biomarker for estrogenic compounds in various fish species whereas a biomarker for androgens, spiggin, is only found in sticklebacks...

Demandt, Marnie H

Uncovering and understanding the processes that have led to the biological diversity we observe today are of fundamental interest in biology. Since direct observation of speciation is usually impossible, knowledge about the processes behind species formation can be gathered by studying mutations, natural/sexual selection, and genetic drift. In this thesis I aim to identify evolutionary processes that cause species divergence and, ultimately, speciation using Swedish cyprinid fish as a model syst...

Sim, Tara K

Thesis (M.S.)--University of Hawaii at Manoa, 2006. / Includes bibliographical references (leaves 39-42). / vi, 42 leaves, bound ill. 29 cm

Nasu, Masaki

Thesis (M.S.)--University of Hawaii at Manoa, 2006. / Includes bibliographical references (leaves 54-56). / vii, 56 leaves, bound ill. 29 cm

Åhlén, Emma

Planktivorous fish affect the species composition, size and morphology of their zooplankton prey by size selective predation. Remains of cladocerans are deposited in the lake sediments and this microfossil community hence reflects the historical changes in the planktivore fish community. Most earlier work on quantitatively inferring past planktivory deals with ephippia (resting eggs) of Daphnia, however these remains are very scarce in northern Swedish lakes. In these lakes, often dominated by f...

Andersson, Daniel

Fish is considered to be a keystone predator in freshwater habitats. Several studies have shown that the species composition of odonates (Odonata) is different between habitats with and without fish, and that odonates depending on the behaviour and physical characteristics of the individual species react differently to the presence of fish, some positively, some negatively and others not at all. This study aims to study the effect of fish as predators on the odonate community, and especially the...

Lai, Chung-yin, Stephanie., 賴仲賢.

published_or_final_version / Architecture / Master / Master of Landscape Architecture

Wang, Man-ping, 王文炳

published_or_final_version / Community Medicine / Master / Master of Public Health

Leung, Wai-yin, Albert., 梁懷彥.

published_or_final_version / Ecology and Biodiversity / Master / Master of Philosophy

鄭穎怡, Cheng, Wing-yi, Rebecca.

published_or_final_version / abstract / toc / Psychology / Master / Master of Philosophy

Webb, B. F.

Where the Avon and Heathcote rivers meet before discharging into the sea, an area of mudflats has been formed, commonly termed the Avon – Heathcote or Christchurch estuary. It is roughly a triangular shaped region, approximately three square miles in area. Of this area about ¾ consists of exposed mudflats at low tide. Previous studies on the estuary biota have been those of Thompson (1929), Bruce (1953), Williams (1959). Rosenberg (1962), and Estcourt (1962). The last author has an excellent re...

Meredith, A. S.

This thesis describes gas exchange, ion and water fluxes and nitrogen metabolism in the Canterbury mudfish, an amphibious fish, which was held in the laboratory in either water or air. The Canterbury mudfish, Neochanna burrowsius, is a swamp dwelling species endemic to New Zealand, which is now rare as its habitats are being destroyed by man. Passive and active exchanges in water or air were assessed using a number of methods, including measurement of gross fluxes, partitioning experiments and...

Hickford, Michael Julian Hames

The distribution and abundance of larval fish in the Kaikoura region, on the northeastern coast of the South Island of New Zealand, was investigated over a four year period (1994 - 1997). Spatial and temporal variability were described on both broad and fine scales. Larval fish assemblages at four stations along an offshore transect were sampled fortnightly over an eighteen month period. The abundance and composition of larval fish assemblages were found to vary seasonally. The spawning activit...

Eikaas, Hans Skailand

Land use change is likely to have influenced the distributions of adults of the New Zealand galaxiid fishes (family Galaxiidae) with life histories involving a juvenile migratory 'whitebait' stage. The influence of interactions between these diadromous migrations, terrestrial habitat fragmentation, migratory barriers and local habitat conditions on the distribution ofkoaro, inanga, and giant, shortjaw and banded kokopu were investigated using a geographical information system approach. A catchm...

Doehring, Anna Katharina

Ongoing urbanisation in lower stream reaches can adversely affect the ecology of river ecosystems by altering freshwater fish distributions. Diadromous fish species (those that migrate between the sea and freshwater) are particularly affected as unimpeded access to and from the sea is necessary for their life-cycle completion. To investigate the extent of the effects that urbanisation have on migratory freshwater fish species, I compared fish community composition between urbanimpacted and un-im...

Steiner Andrews, Caroline Noelle

<p>Floodplain lakes in the Mississippi Alluvial Valley (MAV) provide valuable freshwater resources for states in which they occur. Thirty lakes in portions of Mississippi and Arkansas were surveyed for chlorophyll-<i>a</i> fluorescence and turbidity using handheld meters to determine relationships between chlorophyll-<i>a</i> concentrations and suspended solids. High applicability of handheld meters in the MAV presents economic benefits for monitoring the numerous lakes in the region. Additional...

Eklöv, Peter

<p>Diss. (sammanfattning) Umeå : Umeå universitet, 1995, härtill 6 uppsatser.</p> / digitalisering@umu

Sjöberg, Kjell

The seasonal and diel feeding habits of the goosander, Mergus merganser, the red-breasted merganser, M. serrator, gulls (Larus canus, L. argentatus and L. fuscusj and terns, Sterna hirundo/paradisaea were studied at 64V05'N. Birds' activity patterns were influenced by the nocturnal spawning of the river lamprey (Lampetra fluviatilis). Food selection and food consumption by hand-raised mergansers together with aquarium studies of the diel activity patterns of their most important prey supplemente...

Fahandezhsadi, Fatemehsadat

Freshwater ornamental fish production is a major component of aquaculture in the southeastern United States. Closed recirculating aquaculture systems (RASs) allow freshwater ornamental fish hatcheries to mimic native water quality conditions for sensitive species. Total ammonia-N (TAN) removal is the major concern for closed RASs. Biological nitrification is the common method to control TAN. However, the nitrification process might be impaired in acidic water condition with pH<7. Another issue o...

Lee, Jacqueline Amanda

Inanga (Galaxias maculatus) is an amphidromous fish species that is able to successfully inhabit a variety of salinities. Using an integrated approach this thesis has characterised for the first time the physiological characteristics that facilitate acclimation in inanga. Structural studies using scanning electron microscopy (SEM) and laser scanning confocal microscopy (LSCM) revealed freshwater-acclimated inanga have a high density of apical pits and freshwater-type mitochondria-rich cells (MRC...

Leung, Ka-ming, 梁家銘

The importance of fish culture has been increasing since 1990’s. The steady growth of fish culture helps to ensure a stable supply of fish for human consumption. However, when compared with capture fisheries, production from fish culture is greatly influenced by fish diseases. Outbreaks of fish diseases have caused great economic loss to fish culture. Research has been conducted to understand and reduce the occurrence of fish diseases in fish culture. In Hong Kong, bacterial infection is the mos...

Fu, Chi-wing., 傅志榮.

published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management

Beijer, Kristina

Numerous contaminants are present in mixtures in the aquatic environment. Among these are the azoles, a group of chemicals that includes both pharmaceuticals and pesticides. Azole fungicides are designed to inhibit lanosterol 14-demethylase (cytochrome P450 (CYP) 51), while other azoles are intended to inhibit aromatase (CYP19), i.e. the enzyme catalyzing biosynthesis of estrogens. In fish, a variety of CYP enzymes are involved in biotransformation of waterborne contaminants, and in metabolism o...

Dolder, Craig Nealon

The scattering and attenuation caused by fish schools has been extensively studied for applications in fisheries management and naval sonar. The literature contains extensive in situ measurements of scattering by fish schools, however significant uncertainties exist with respect to characterizing the size, quantity, and distribution of fish within the schools, that confounds accurate measurement-model comparison. Hence there is a need for application of measurement techniques that can more preci...

Whitaker, Keith William

Ecological context, sensory inputs, and the internal physiological state are integrated for an animal to make appropriate behavioral decisions. However, these factors have rarely been studied in the same system. In the African cichlid fish Astatotilapia burtoni, males alternate between four phenotypes. Two are determined by social status and two are identified by the principle body coloration (yellow or blue). When socially dominant (DOM), fish display bright body coloration and a wealth of aggr...

Lyssimachou, Angeliki

No description available.

Boys, Craig Ashley, n/a

Many aspects concerning the association of riverine fish with in-channel habitat remain poorly understood, greatly hindering the ability of researchers and managers to address declines in fish assemblages. Recent insights gained from landscape ecology suggest that small, uni-scalar approaches are unlikely to effectively determine those factors that influence riverine structure and function and mediate fish-habitat associations. There appears to be merit in using multiple-scale designs built upon...

Webb, Jennifer Colley

This dissertation assesses the levels of mercury in fish and human populations and PAHs in local communities along three rivers in the Ecuadorian and Peruvian Amazon. Land use changes in the Amazon are begetting numerous negative impacts on both ecosystems and local populations. One negative consequence of deforestation is the contamination of local ecosystems by mercury (Hg), a potent neurotoxic agent, which is leached from soils when river-side plots are cleared. In the Andean Amazon, the incu...

Bargelletti, Olivia.

This study explores the morphology and electrical behavior of breeding weakly electric fish. Wave-type electric fish communicate by means of a continuous oscillatory electric signal produced by an electric organ. The electric organ discharges at frequencies which are sexually dimorphic in many species of electric fish. This dimorphism is thought to be attributed to female mate choice, although to date, there is no evidence for mate choice or intrasexual competition to have driven the evolution o...

Welch, Catherine Jane.

No description available.

Brassard, Paul.

No description available.

Sequeira-Munoz, Amaral.

The spoilage pattern of carp (Cyprinus carpio) fillets was investigated. The studies were aimed at evaluating the potential use of pressure-shift freezing to reduce quality deterioration during frozen storage. The effects of pressure treatment at low temperature on fish carp fillets were evaluated and conditions were chosen to reduce any adverse effect on the quality of fish fillet. Pressure-shift freezing treatment was applied to carp fillets and biochemical properties were evaluated and correl...

Pomerleau, Yvan N.

The aim of this study was to maximize good quality grass silage utilization either by supplying a source of rumen undegradable protein or by a reduction of the concentrate in the diet. A randomized incomplete block design was used to evaluate feed intake, milk production and health incidence occurring in fifty-nine Holstein dairy cow (11 primiparous) distributed randomly to receive three different diets between wk 4 and 24 of lactation. The diets were composed of grass silage (predominance of ti...

The skin of many fishes contains large epidermal club cells (ECCs) that are known to release chemicals (alarm cues) that warn other fishes of danger. Initial research on ECCs focussed on their role in predator avoidance behaviour, however later research revealed that these cells might also have immune functions. Anthropogenic activities have dramatically increased over the past decades, with the consequence that many organisms simultaneously get exposed to multiple environmental stressors. We ha...

Rabasco, Robert

Northern pike ('Esox lucius'), yellow perch ('Perca flavescens'), and pumpkinseed ('Lepomis gibossus ') rely on vegetated littoral zones as spawning substrate, foraging areas, and refuge from predation. However, the removal of littoral zone habitat has increased in the past twenty-five years. This led Department of Fisheries and Oceans Canada (DFO) researchers to study the effects of habitat loss on northern pike production in Lake 191 in the Experimental Lakes area (ELA) in northwestern Ontari...

Brix, K. V., Deforest, D. K., Fairbrother, Anne, Adams, William J.

Selenium-induced fish kills in Belews Lake, North Carolina in the late-1970s resulted in a substantial amount of research on selenium effects to aquatic life. Similarly, selenium-induced teratogenesis in aquatic birds at Kesterson Reservoir, California in the mid-1980s resulted in extensive research on selenium effects to aquatic birds. Unlike many other contaminants for which water exposure is the critical pathway for environmental effects, selenium ecotoxicology is driven by bioaccumulatio...

Latorre, Rocco <1981>

The ingestion of a meal evokes a series of digestive processes, which consist of the essential functions of the digestive system: food transport, secretory activity, absorption of nutrients and the expulsion of undigested residues do not absorbed. The gastrointestinal chemosensitivity is characterized by cellular elements of the endocrine gastrointestinal mucosa and nerve fibers, in particular of vagal nature. A wide range of mediators endocrine and/or paracrine can be released from various endo...

Cazan, Alfy Morales

<p> This study assessed the occurrence and impacts of maternal metal transfer in live-bearing fish. The occurrence was investigated in two different species (<i>Gambusia affinis</i>and <i>Heterandria formosa</i>), while the impacts were studied only in <i>G. affinis.</i> Occurrence and impacts were addressed by exposing gravid females for 10 days to 0.15 &mu;M of copper or cadmium, transferring the fish to clean water, monitoring their reproduction and collecting newborn offspring for further an...

Harford, Andrew James, andrew.harford@rmit.edu.au

The Murray-Darling basin is the largest river system in Australia with significant economic, social, recreational and cultural value. It supplies water for drinking and agriculture to a large inland area of the eastern and southern states of Australia. It is also the ultimate sink for many environmental contaminants that result from human activities within the catchment. Aquatic organisms live intimately with their environment and may be continuously exposed to these contaminants throug...