Avancerad sökning

Hittade 5 uppsatser som matchar ovanstående sökkriterier.

  1. 1. Consequences on population dynamics following regained connectivity in pike (Esox lucius) spawning location

    Master-uppsats, Linnéuniversitetet/Institutionen för biologi och miljö (BOM)

    Författare :Oscar Adolfsson; [2020]
    Nyckelord :dmixture; emigration; downstream spawning; pike-factory; restoration; sourcesink dynamics; spawning strategy;

    Sammanfattning : Distributional movements of subpopulations may act as a buffer to prevent the loss of a species in a certain area. However, within subpopulations adaptations may evolve that makes the inhabitants of a certain habitat to better cope with prevailing environmental conditions. LÄS MER

  3. 2. Sampling methods of the wels catfish (Silurus glanis) in freshwater lakes : management of a vulnerable species

    Master-uppsats, SLU/Dept. Of Aquatic Resources

    Författare :David Östby; [2018]
    Nyckelord :sampling; gear; monitoring; Wels catfish; Silurus glanis; management; vulnerable spieces; electrofishing; acoustic camera; fyke nets; lake;

    Sammanfattning : Sweden hosts the northernmost natural population of wels catfish (Silurus glanis) in the world. The populations of the species decreased severely in the 20th century, mainly due to different sources of anthropogenic impact. LÄS MER

  4. 3. An ecological study of the migration, food composition and relative abundance of three-spined stickleback (Gasterosteus aculeatus) in a shallow area in Kalmar Sound.

    Kandidat-uppsats, Linnéuniversitetet/Institutionen för biologi och miljö (BOM)

    Författare :Peter Söderling; [2013]
    Nyckelord :Three-spined stickleback; Gasterosteus aculeatus; migration; abundance; population; decline; increase; food; prey; predate; pike; perch; roach; spring; spawn; recruitment; shallow; Kalmar; Baltic; Storspigg; spigg; vandring; förekomst; population; populationsökning; populationsminskning; föda; byte; predera; predator; gädda; abborre; mört; vår; vårlekande; föryngring; lek; grunt; Kalmar; Kalmarsund; Östersjön;

    Sammanfattning : The populations of three–spined sticklebacks (Gasterosteus aculeatus) in the Baltic Sea have increased tenfold over the last decade. A large increase in abundance can alter the offshore and coastal food webs. LÄS MER

  5. 4. Vandring av vårlekande fisk och jämförelse av fångst mellan ryssja och strömöversiktsnät i Hammerstaån, Stockholms län

    Kandidat-uppsats, Institutionen för fysik, kemi och biologi

    Författare :Ulf Johansson; [2011]
    Nyckelord :Spring-spawning fish; inventory; Migation; bream; fyke nets; Strömöversiktsnät; Hammerstaån; Muskån; Vårlekande fisk; karpfiskar; vimma; inventering; provfiske;

    Sammanfattning : During the last two hundred years many wetlands and streams in Sweden have been lowered to provide land for agriculture and forestry. Some of the coastal wetlands and streams probably served as spawning sites for certain species of fish in the Baltic Sea, but the present situation is not well known. LÄS MER

  7. 5. Vandring av vårlekande fisk och jämförelse av fångst mellan ryssja och strömöversiktsnät i Hammerstaån, Stockholms län

    Kandidat-uppsats, Institutionen för fysik, kemi och biologi

    Författare :Ulf Johansson; [2011]
    Nyckelord :Migration; inventory; spring-spawning fish; bream; fyke nets; perch; strömöversiktsnät; Hammerstaån; Muskån; vårlekande fisk; vimma;

    Sammanfattning : During the last two hundred years many wetlands and streams in Sweden have been lowered to provide land for agriculture and forestry. Some of the coastal wetlands and streams probably served as spawning sites for certain species of fish in the Baltic Sea, but the present situation is not well known. LÄS MER