Náttúra og tilfeingi
Sambandið ímillum djóraæti og havfrøðiligar broytingar kring Føroyar í trý áratíggju
Eilif Gaard, Hjálmar Hátún, Sólvá Jacobsen, Ian Salter
Stuðul úr Granskingargrunninum:
Summary of project. Zooplankton is a crucial component of marine ecosystems due to their central role in the marine trophic food webs. The Faroe Shelf sustains several economically important fish stocks such as cod, haddock and saithe. These rely on zooplankton for growth and survival during the larvae stages. However, large fluctuations are observed within the ecosystem on the Faroe Shelf, which may have severe economical and sociological consequences. The shelf ecosystem is largely composed by neritic (shelf) zooplankton species but the region is also influenced by the surrounding oceanic environment. The variable inflow from the oceanic environment appears to cause a zooplankton shift during the summer, with some years being characterized by a dominance of neritic species and other years of the horizontally advected oceanic species. A recent study has also identified different bloom dynamics on the Central Shelf, Eastern Banks and Western Region, which suggest variability in the zooplankton community structure across the shelf. This suggests that the Faroe Shelf is not as homogeneous as previously thought. Since the early 1990s, the Faroe Marine Research Institute has been monitoring the oceanographic conditions on two standard sections, radiating east and west from the Faroe Islands. During this long observational period, the hydrographic time series revealed unusual cold and low-saline condition in the mid 1990s, while the hydrographic properties continuously increased after 1996 and reached historically high values around 2003. In 2016, the time series recorded the lowest salinity and temperature since the mid 1990s. These periods are also registered as ‘key periods’ in large-scale oceanographic changes over the North Atlantic. The zooplankton dynamics along the sections is largely unknown. Thus, valuable time series can potentially be generated, which are expected to reveal information on the Faroe shelf ecosystem functioning and variability as well as variability in the surrounding oceanic environment during the past three decades, which still remains clouded. The aim of the proposed post-doc study is to investigate the zooplankton abundance and composition across the Faroe Shelf and into the open ocean. This will be linked to the (i) hydrographical conditions and (ii) ecosystem fluctuations on and off the Faroe plateau throughout the observation period.