Sökning: "Fish migration"
Visar resultat 1 - 5 av 59 avhandlingar innehållade orden Fish migration.
1. Downstream migration of salmonids in regulated rivers : Non-conventional methods for fish diversion
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. Atlantic salmon in regulated rivers : Migration, dam passage, and fish behavior
Sammanfattning : Hydropower dams block migration routes and disrupt longitudinal connectivity in rivers, thereby posing a threat to migratory fish species. Various fish passage solutions have been implemented to improve connectivity with varying success. LÄS MER
3. Does fish health matter? The Utility of Biomarkers in Fish for Environmental Assessment
Sammanfattning : Two common strategies to assess exposure to environmental toxicants are to measure chemical concentrations in the environment and to examine the presence of certain species that are known to be sensit... merive to pollution. LÄS MER
4. Waterfowl in temperate eutrophic lakes - Interactions with macroinvertebrates, submerged vegetation and fish
Sammanfattning : The aim of this thesis was to explore some of the important links between waterfowl and the biota in shallow eutrophic lakes in temperate areas. Waterfowl depend on macroinvertebrates as sources of protein and calcium, which are essential for egg production and growth. Macroinvertebrates in turn depend on submerged vegetation for food and shelter. LÄS MER
5. Large-scale releases of native species : the mallard as a predictive model system
Sammanfattning : Human alteration of natural systems, and its consequences are of great concern and the impact on global ecosystems is one of the biggest threats that biodiversity stands before. Translocations of invasive species, as well as intraspecific contingents with non-native genotypes, whether they are deliberate or unintentional, are one such alteration and its consequences are continuously being assessed. LÄS MER