Líffræðifélag Íslands - biologia.is
Líffræðiráðstefnan 2021
Erindi/veggspjald / Talk/poster V29
Höfundar / Authors: Anja Nickel (1), Guðbjörg Ásta Ólafsdóttir (1)
Starfsvettvangur / Affiliations: 1. Rannsóknarsetur Vestfjarða, Háskoli íslands
Kynnir / Presenter: Anja Nickel
Atlantic cod (Gadus morhua) and saithe (Pollachius virens) occur in the same coastal habitats during their early life stage, follow similar seasonal distribution patterns and show high similarity among their diets. This spatial and temporal niche overlap can be expected to increase competition between the two species. Since Darwin’s competitive exclusion principle, which stated that ecological similar species could not coexist, numerous niche-theories have been developed and concluded, that physiological and ecological strategies allow sympatric species with a high niche-overlap to coexist. Strategies to reduce the spatial overlap in fish include temporal and spatial resource partitioning, for example different diel activities and microhabitat preferences. We examined the spatial use of juvenile Atlantic cod and saithe throughout autumn/winter 2020 by implanting acoustic V5-D tags (Vemco) in 22 cod and 19 saithe and tracking their movement within a network of 33 VR2W-180kHz receivers. The receivers were set-up in six gates, which allowed the detection of directional movement of tagged fish inside large areas of a fjord. Preliminary results of the study show movement patterns and survival of the individual juveniles and allows us to draw first conclusion of spatial variation between and within the two species. The data will provide a better understanding of the potential strategies of Atlantic cod and saithe to decrease inter- and intraspecific spatial overlap.