You searched for subject:(trophic condition).
Showing records 1 – 4 of
4 total matches.
No search limiters apply to these results.
1.
Ankrah, Beryl A.
Feeding Ecology of the Round Goby (Neogobius melanostomus- Pallas, 1814) in Two Contrasting Environments: Eastern Lake Erie and a Fourth Order Stream.
Degree: 2011, Buffalo State College
URL: https://digitalcommons.buffalostate.edu/biology_theses/1 
► I assessed the feeding ecology of the round goby in eastern Lake Erie and a recently invaded stream (Ellicott Creek). My objectives were: 1) to…
(more)
▼ I assessed the feeding ecology of the round goby in eastern Lake Erie and a recently invaded stream (Ellicott Creek). My objectives were: 1) to compare the length-weight relationship and condition of round gobies in eastern Lake Erie and Ellicott Creek, 2) to evaluate the δ15N and δ13C content of the food web of round gobies in the lake and the creek, and 3) to compare the trophic position of round gobies in the two different environments. Round gobies in eastern Lake Erie had positive allometric growth and were more rotund than round gobies in the creek, which had isometric growth. Round gobies in the lake were more enriched in δ13C than round gobies in the creek, an indication that the C-source that fuels each food web is different. In the lake, there were variations in the δ15N content of the round gobies depending on their size, whereas the δ15N content of the round gobies in the creek was similar for all fish sizes. However, the overall δ15N content of round gobies in the lake and the stream were not statistically different. In general, the trophic position of round gobies in eastern Lake Erie was higher than that of round gobies in Ellicott Creek. I conclude that round gobies in the tributary streams of the Great Lakes are still expanding their range and have the potential to severely alter stream ecosystems. Round gobies in the lake are well established and play a vital role in the lake food web.
Subjects/Keywords: round goby; food web; trophic position; stable isotopes; goby diet; fish condition; Terrestrial and Aquatic Ecology
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Ankrah, B. A. (2011). Feeding Ecology of the Round Goby (Neogobius melanostomus- Pallas, 1814) in Two Contrasting Environments: Eastern Lake Erie and a Fourth Order Stream. (Thesis). Buffalo State College. Retrieved from https://digitalcommons.buffalostate.edu/biology_theses/1
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Ankrah, Beryl A. “Feeding Ecology of the Round Goby (Neogobius melanostomus- Pallas, 1814) in Two Contrasting Environments: Eastern Lake Erie and a Fourth Order Stream.” 2011. Thesis, Buffalo State College. Accessed January 28, 2021.
https://digitalcommons.buffalostate.edu/biology_theses/1.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Ankrah, Beryl A. “Feeding Ecology of the Round Goby (Neogobius melanostomus- Pallas, 1814) in Two Contrasting Environments: Eastern Lake Erie and a Fourth Order Stream.” 2011. Web. 28 Jan 2021.
Vancouver:
Ankrah BA. Feeding Ecology of the Round Goby (Neogobius melanostomus- Pallas, 1814) in Two Contrasting Environments: Eastern Lake Erie and a Fourth Order Stream. [Internet] [Thesis]. Buffalo State College; 2011. [cited 2021 Jan 28].
Available from: https://digitalcommons.buffalostate.edu/biology_theses/1.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Ankrah BA. Feeding Ecology of the Round Goby (Neogobius melanostomus- Pallas, 1814) in Two Contrasting Environments: Eastern Lake Erie and a Fourth Order Stream. [Thesis]. Buffalo State College; 2011. Available from: https://digitalcommons.buffalostate.edu/biology_theses/1
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of Canterbury
2.
Burrell, Teresa Kathleen.
Trophic State in Canterbury Waterways.
Degree: MS, Environmental Sciences, 2011, University of Canterbury
URL: http://dx.doi.org/10.26021/9040
► Aquatic eutrophication is a serious global problem, associated with phytoplankton blooms, hypoxia, and loss of species. The objective of this thesis was to advance understanding…
(more)
▼ Aquatic eutrophication is a serious global problem, associated with phytoplankton blooms, hypoxia, and loss of species. The objective of this thesis was to advance understanding of stream and lake eutrophication within Canterbury (South Island, New Zealand). I investigated three key questions: 1) How do riparian characteristics control stream trophic state, 2) how does stream trophic state in the Canterbury region compare to stream trophic state nationally and internationally, and 3) what factors control trophic state in Te Wairewa/Lake Forsyth. I measured rates of stream community metabolism in 21 Canterbury streams over a gradient of riparian canopy cover, and conducted a literature review of national and international studies of stream metabolism. I also examined the occurrence of cyanobacterial blooms in Te Wairewa in relation to water quality and weather from 17 years of measurements, and performed series of nutrient addition assays on the lake to assess nutrient limitation. I found that riparian characteristics strongly controlled stream trophic state by shading, thereby reducing photosynthetic productivity. This overwhelmed the effects of high nitrate concentrations, which increased primary production. Compared to national and international rates of stream metabolism, Canterbury streams were strongly heterotrophic, with low rates of autotrophic production. Catchment streams draining into Te Wairewa were unlikely to be the main source of nutrients supporting large cyanobacterial blooms. Instead, internal lake nutrient loading mechanisms associated with calm weather were likely to supply blooms. My results emphasize the importance of light limitation, nitrogen and heterotrophy in controlling stream trophic state, and nutrient supply and weather in controlling lake trophic state.
Subjects/Keywords: Aquatic; eutrophication; phytoplankton blooms; hypoxia; riparian condition; trophic state; Canterbury; Te Wairewa; Lake Forsyth; stream community metabolism
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Burrell, T. K. (2011). Trophic State in Canterbury Waterways. (Masters Thesis). University of Canterbury. Retrieved from http://dx.doi.org/10.26021/9040
Chicago Manual of Style (16th Edition):
Burrell, Teresa Kathleen. “Trophic State in Canterbury Waterways.” 2011. Masters Thesis, University of Canterbury. Accessed January 28, 2021.
http://dx.doi.org/10.26021/9040.
MLA Handbook (7th Edition):
Burrell, Teresa Kathleen. “Trophic State in Canterbury Waterways.” 2011. Web. 28 Jan 2021.
Vancouver:
Burrell TK. Trophic State in Canterbury Waterways. [Internet] [Masters thesis]. University of Canterbury; 2011. [cited 2021 Jan 28].
Available from: http://dx.doi.org/10.26021/9040.
Council of Science Editors:
Burrell TK. Trophic State in Canterbury Waterways. [Masters Thesis]. University of Canterbury; 2011. Available from: http://dx.doi.org/10.26021/9040
3.
Alexandre Peressin.
Impactos da urbanização na ictiofauna de riachos na parte superior da bacia do Alto Rio Paranapanema (SP), Brasil.
Degree: 2013, Universidade Federal de São Carlos
URL: http://www.bdtd.ufscar.br/htdocs/tedeSimplificado//tde_busca/arquivo.php?codArquivo=6769
► Ecossistemas aquáticos têm sofrido forte pressão antropogênica, que se manifesta na construção de barragens, captação de água, poluição química, destruição do ambiente de entorno, principalmente…
(more)
▼ Ecossistemas aquáticos têm sofrido forte pressão antropogênica, que se manifesta na construção de barragens, captação de água, poluição química, destruição do ambiente de entorno, principalmente mata ripária, e alterações estruturais como canalizações e aporte de sedimentos. A assembleia de peixes pode responder de diversas formas a estas alterações ambientais, dado que as espécies possuem diferentes exigências fisiológicas e de habitats. Com isso, algumas espécies podem ser eliminadas e outras favorecidas. Cientes da necessidade de compreender e identificar o padrão das respostas da assembleia e organismos aos vetores de impacto, neste trabalho buscamos investigar como a ictiofauna responde à urbanização. Para isso, os peixes foram coletados em quatro trechos localizados em áreas urbanas e cinco localizados em áreas não urbanas, sempre em riachos da parte superior da bacia do alto rio Paranapanema. O capítulo I buscou detectar alterações nas variáveis físicas do hábitat, na estrutura e na composição da assembléia de peixes. Utilizando as variáveis ambientais, os trechos foram ordenados no sentido urbanizado-não urbanizado, sendo que estes últimos apresentaram valores maiores de sombreamento, área, substrato e vegetação de entorno. Verificamos que a estrutura da assembleia, representada pelos índices de diversidade de Shannon, equabilidade de Pielou e riqueza de Margalef, não sofreu alterações em resposta à urbanização, bem como a relação entre abundância e biomassa. No entanto, a composição da assembleia foi diferente e a riqueza estimada com base nas espécies raras foi menor nos trechos urbanos. Simultaneamente, a variação nos componentes ambientais explicou a variação na composição da assembleia. Estes resultados evidenciam um processo de substituição de espécies descrito para ambientes alterados, no qual espécies pré-adaptadas às novas condições aumentam em abundância e outras antes ausentes se estabelecem. Assim, a diversidade é mantida, porém, alterando a composição. Em geral, espécie onívoras forrageadoras de meia água foram mais abundantes em áreas urbanas, ao passo que loricarídeos e invertívoros bentônicos apresentaram maior abundancia média em trechos não urbanos. No Capítulo II, o objetivo foi identificar alterações na estrutura trófica, composição do substratro, influência deste na estrutura trófica e condição corporal. Para isso, a dieta das espécies foi quantificada de acordo com o método do Grau de Preferência Alimentar (GPA) para seis itens: material vegetal, algas, detrito, invertebrados, insetos e peixe. De acordo com os itens consumidos, as espécies foram classificadas em categorias tróficas. Quatorze espécies foram consideradas invertivoras/detritívoras, sete herbívoras/detritívoras, sete onívoras e uma piscívora. Quatro espécies de invertívoros/insetívoros foram exclusivas de trechos não urbanos e uma dos urbanos. Três espécies herbívoras/detritívoras foram exclusivas de riachos do tipo não urbano, o inverso dos onívoros, com 3 espécies exclusivas de riachos do tipo urbano. A partir da…
Advisors/Committee Members: Mauricio Cetra, George Mendes Taliaferro Mattox, Giulianna Rondineli Carmassi.
Subjects/Keywords: ictiologia Rio Paranapanema (SP); ecossistema aquático; urbanização; riachos urbanos; composição da assembleia; estrutura da assembleia; categorias tróficas; estrutura trófica; condição corporal; CIENCIAS BIOLOGICAS; assemblage composition; body condition; ichthyofauna; assemblages structure; trophic categories; trophic structure; urban stretches; urbanization
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Peressin, A. (2013). Impactos da urbanização na ictiofauna de riachos na parte superior da bacia do Alto Rio Paranapanema (SP), Brasil. (Thesis). Universidade Federal de São Carlos. Retrieved from http://www.bdtd.ufscar.br/htdocs/tedeSimplificado//tde_busca/arquivo.php?codArquivo=6769
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Peressin, Alexandre. “Impactos da urbanização na ictiofauna de riachos na parte superior da bacia do Alto Rio Paranapanema (SP), Brasil.” 2013. Thesis, Universidade Federal de São Carlos. Accessed January 28, 2021.
http://www.bdtd.ufscar.br/htdocs/tedeSimplificado//tde_busca/arquivo.php?codArquivo=6769.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Peressin, Alexandre. “Impactos da urbanização na ictiofauna de riachos na parte superior da bacia do Alto Rio Paranapanema (SP), Brasil.” 2013. Web. 28 Jan 2021.
Vancouver:
Peressin A. Impactos da urbanização na ictiofauna de riachos na parte superior da bacia do Alto Rio Paranapanema (SP), Brasil. [Internet] [Thesis]. Universidade Federal de São Carlos; 2013. [cited 2021 Jan 28].
Available from: http://www.bdtd.ufscar.br/htdocs/tedeSimplificado//tde_busca/arquivo.php?codArquivo=6769.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Peressin A. Impactos da urbanização na ictiofauna de riachos na parte superior da bacia do Alto Rio Paranapanema (SP), Brasil. [Thesis]. Universidade Federal de São Carlos; 2013. Available from: http://www.bdtd.ufscar.br/htdocs/tedeSimplificado//tde_busca/arquivo.php?codArquivo=6769
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of Gothenburg / Göteborgs Universitet
4.
Lord, Hans.
Morphological antipredator adaptations in water fleas.
Degree: 2009, University of Gothenburg / Göteborgs Universitet
URL: http://hdl.handle.net/2077/21030
► Some Bosmina and Daphnia species have the ability to develop extreme morphological antipredator defences, such as long antennules, high carapaces and helmets. The relative sizes…
(more)
▼ Some Bosmina and Daphnia species have the ability to develop extreme morphological antipredator defences, such as long antennules, high carapaces and helmets. The relative sizes of these plastic traits may differ substantially between populations, and also between individuals within a population, between sexes and during ontogeny. In this thesis I examine how abiotic factors (trophic levels and temperature) and biotic factors (fish and invertebrate predators) affect the size and shape of these traits.
In the first two studies, calculations based on experimental results using physical morphological models sinking in glycerine, were used to estimate body drag and energy consumption in Bosmina. Eubosmina longispina, with a low carapace and short antennules, and Eubosmina coregoni gibbera, with a very high carapace and long antennules, were examined. At 5○C, E. c. gibbera had 32-45 % higher body drag than E. longispina. At 20○C the difference was 20-45 %. A model of swimming predicted that, all else being equal, this difference should result in 18-20 % (at 5○C) or 14-16 % (at 20○C) lower swimming speed for E. c. gibbera than for E. longispina. This indicates substantial hydrodynamic costs of the morphological antipredator defences, particularly in low temperatures.
The morphological antipredator defences in E. c. gibbera are larger and more variable in females than in males. Male models had lower body drag than models of asexual and sexual females, suggesting that males can swim 14-28 % faster with the same energy consumption. High speed video documentation of swimming E. c. gibbera showed that males advanced 55-73 % further than females in each swimming stroke. Hydrodynamic body drag may therefore have significant implications for swimming and evolution of sexual dimorphism in water fleas. Males may lack the defensive, but hydrodynamically expensive, high carapace of female E. c. gibbera probably because competition over mates favours low body drag.
The morphology and size of heads and trunks in Daphnia cristata individuals were studied in twenty lakes in the same drainage basin. The lakes showed a variation in lake total phosphorus and in densities of invertebrate predators and fish. In the end of the summer
D. cristata had varying shape and size of their heads. Our results indicate that D. cristata, in nutrient rich lakes, show adaptive morphological defences against both visually hunting and size limited predators.
Female D. cristata head shape, in the examined lakes, varied from small and rounded to large and curved. A significant positive correlation between lake total phosphorus and the allometric head coefficients was found, suggesting that the most extremely shaped heads are found in nutrient-rich lakes.
Subjects/Keywords: Body drag; Daphnia cristata; Reynolds number; viscosity; zooplankton; Bosmina; swimming velocity; cyclomorphosis; sexual dimorphism; head area; helmet angle; trophic condition; allometry; invertebrate predator; fish
Record Details
Similar Records
Cite
Share »
Record Details
Similar Records
Cite
« Share
❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Lord, H. (2009). Morphological antipredator adaptations in water fleas. (Thesis). University of Gothenburg / Göteborgs Universitet. Retrieved from http://hdl.handle.net/2077/21030
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Lord, Hans. “Morphological antipredator adaptations in water fleas.” 2009. Thesis, University of Gothenburg / Göteborgs Universitet. Accessed January 28, 2021.
http://hdl.handle.net/2077/21030.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Lord, Hans. “Morphological antipredator adaptations in water fleas.” 2009. Web. 28 Jan 2021.
Vancouver:
Lord H. Morphological antipredator adaptations in water fleas. [Internet] [Thesis]. University of Gothenburg / Göteborgs Universitet; 2009. [cited 2021 Jan 28].
Available from: http://hdl.handle.net/2077/21030.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Lord H. Morphological antipredator adaptations in water fleas. [Thesis]. University of Gothenburg / Göteborgs Universitet; 2009. Available from: http://hdl.handle.net/2077/21030
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
. 
Open Access Theses and Dissertations