Sökning: "fish populations"

Visar resultat 1 - 5 av 131 avhandlingar innehållade orden fish populations.

  1. 1. Downstream migration of salmonids in regulated rivers : Non-conventional methods for fish diversion

    Författare :Johan Leander; Jonatan Klaminder; Micael Jonsson; Gustav Hellström; Paul Kemp; Umeå universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Fish migration; Fish passage; Fish guidance; Hydropower; Atlantic salmon; Brown trout; Bubble barrier; Non-physical barrier;

    Sammanfattning : Passages through hydropower plants can be fatal for downstream migrating salmonids (Salmo spp.). This is particularly true for large adults that are returning to the ocean after spawning. LÄS MER

  2. 2. Endocrine disruption in fish : Effects of 17α-ethinylestradiol exposure on non-reproductive behavior, fertility and brain and testis transcriptome

    Författare :Tove Porseryd; Inger Porsch Hällström; Ioanna Katsiadaki; Södertörns högskola; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; 17α-ethinylestradiol; endocrine disrupting chemical; fish; behavior; fertility; transcriptome; RNA sequencing; Environmental Studies; Miljövetenskapliga studier; Östersjö- och Östeuropaforskning; Baltic and East European studies;

    Sammanfattning : Aquatic environments are the end recipient for most anthropogenic chemical pollutants. One common chemical pollutant found in the aquatic environment is 17α-ethinylestradiol (EE2), a synthetic estrogen used in contraceptive pills. LÄS MER

  3. 3. Climate change impacts on production and dynamics of fish populations

    Författare :Per Hedström; Pär Byström; Jan Karlsson; Peter Eklöv; Umeå universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Temperature; terrestrial dissolved organic carbon; light extinction; GPP; recruitment; winter mortality; metabolism; cohort competition; fish production; fish biomass;

    Sammanfattning : Ongoing climate change is predicted to increase water temperatures and export of terrestrial dissolved matter (TDOM) to aquatic ecosystems influencing ecosystem productivity, food web dynamics and production of top consumers. Ecosystem productivity is mainly determined by the rates of primary production (GPP) in turn controlled by nutrients, light availability and temperature, while temperature alone affect vital rates like consumption and metabolic rates and maintenance requirements of consumers. LÄS MER

  4. 4. Assembly of Gut Microbial Communities in Freshwater Fish and Their Roles in Fish Condition

    Författare :Yinghua Zha; Richard Svanbäck; Eva Lindström; Peter Eklöv; Brendan Bohannan; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; freshwater fish; gut microbial communities; predation stress; diet; fish condition; bacterial colonization; metacommunity theory; dispersal; Biology with specialization in Limnology; Biologi med inriktning mot limnologi;

    Sammanfattning : Animal hosts provide associated microorganisms with suitable ecological niches in their intestines. Microbes help their hosts to digest food, protect against pathogens, and influence the host’s metabolisms. Compositional variation of gut microbial communities is common among hosts, and may affect the health status of hosts. LÄS MER

  5. 5. Offshore wind farms - ecological effects of noise and habitat alteration on fish

    Författare :Mathias H. Andersson; Sören Nylin; Magnus Wahlberg; Stockholms universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; renewable energy; fish population; artificial reef; attraction vs. production; habitat structure; reef effect; FAD; bioacoustics; noise disturbance; fish behaviour; detection range; threshold; masking; fish communication and hearing; Marine ecology; Marin ekologi; zoologisk ekologi; Animal Ecology;

    Sammanfattning : There are large gaps in our understanding how fish populations are affected by the anthropogenic noise and the alteration of habitat caused by the construction and operation of offshore wind farms. These issues are of great importance as the construction of offshore wind farms will increase all over the world in the near future. LÄS MER