Year of grant:
2015

Research Area:
Náttúra og náttúrutilfeingi

Project type:
Ph.d.verkætlan

Project title:
Vatnskiftið í Sundalagnum og grannafirðum: Ein modelkanning.

Grant number:
0445

Project manager:
Sissal Erenbjerg

Institution/company:
Fiskaaling

Other participants:
Knud Simonsen, Eigil Kaas, Jon Albretsen, Bogi Hansen

Project period:
Original: 01.01.2016-31.12.2018
Final: 01.11.2016-31.08.2021

Total budget:
3.329.522

Grant from the FRC in DKK:
640.000

Project description:
Original
The coast of Sundalagi and adjacent fjords hosts more than half of the faroese population, some of the most busy harbours and a large fraction of the industry in the country. In these fjords a significant part of the faroese export of farmed salmon, in addition to other marine products, is grown out. Detailed understanding of the circulation and the water exchange between the various basins in this fjord system is a prerequisite for skilful spatial management and risk assessments of potential accidental pollution. In the aquaculture unerstanding the dispersion of diseases and parasites, in particular the sea lice, from one site to another is of vital interest.

The primary production in Faroese fjords is generally 2-3- times higher than in other countries at the same lattitude. This is suggested to be linked to the relatively small size of the fjords and the variable weather conditions. One aim of this project is to get a better understanding of the underlying physical processes responsible for the high primary production. The fjord system of Sundalagi and adjacent fjords includes several basins, where stagnant bottom layer may develop during summer, which may cause benthic oxygen depletation. Understanding the hydrography, the acting vertical mixing mechnism and how it may affect the primary production is thus essential in estimating the biological carrying capacity of these basins, which also is of increasing international awarenes in aquaculture management strategies.

In this PhD-project a high resolution numerical 3D-model will be implemented for the Sundalagi and adjacent fjords in order to understand the circulation and water exchange between the different part of the fjords, which has a quite complex bathymetry and variable hydrography. The model simulations will be validated towards a vast amount of data including hydrographic and current profile data both from spatial surveys and timeseries from moored instruments. The influence of various weather conditions on the hydrography and circulation on both short and seasonal scale will be investigated with emphasis on influence on the stratification, the vertical mixing processes, residence time in the various basins and how present fish farms are dynamically connected. Further, a sea lice model will be coupled to the physical model in order to increase the understanding of the spatial, vertical and temporal dispersion of the first stages of sea lice obtained from recent succesful plankton net trawlings in the region.

Final
This project has developed High-Performance Computing (HPC) competences at Fiskaaling, with focus on the ocean model ROMS. Further more a simulated data set for the Faroe Shelf and the fjords are obtained for the year 2013. These data a validated in 2 scientific paper and a technical report. The papers state the importance of the amphidromic region around the Faroes and in detail describe the water exchange in the fjord Sundalgið Norður, with a modeling approach. It is concluded that the model system ROMS, as applied in the FarCoast nested model system, is a great tool for further investigations on the Faroese shelf and in particular the central fjords.

Project status:
Liðug

Project output:
Scientific articles, books, thesis etc.
Thesis entitled: Oceanography of the Faroe Shelf and Sundalagið Norður, by Sissal Vágsheyg Erenbjerg. Defended on 15th December 2021.

Paper 1: Erenbjerg, S. V., Albretsen, J., Simonsen, K., Sandvik, A. D., & Kaas, E. (2020). A step towards high resolution modeling of the central Faroe shelf circulation by FarCoast800. Regional Studies in Marine Science, 40.

Paper 2: Erenbjerg, S. V., Albretsen, J., Simonsen, K., Olsen, E., Kaas, E., & Hansen, B. (2021). A tidally driven estuary close to an amphidromy. Ocean Science, 17, 1639-1655. https://doi.org/10.5194/os-17-1639-2021

Other results, such as unpublished articles, patents, computer systems, original models and new procedures
FarCoast 800, FarCoast160 and FarCoast32 model systems

Publications outside the scientific community, i.e. lectures, periodicals, articles in newspapers, television and radio
Public presentation at Vísindavøkan from September 2020: https://kringvarp.fo/sending/visindavoka-fyrilestrar?sid=118849&page=1

Storage and access rights til collected data
The data are available locally and can be requested for scientific purposes in cooperation with Fiskaaling and Institute of Marine research in Bergen.



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