Location and physical characteristics
Figure 1: Faroe-Shetland Channel Offshore Marine Region the thicker white line delineates the extent of the Faroe-Shetland Channel OMR. For a map of all SMRs and OMRs, see Figure 5 here
| Sea area (km2) | 42,752 |
| Deepest point (m) | 2,418 |
| Shallowest point (m) | 343 |
| Average depth (m) | 1,304 |
| Tides (m) | 1.1 – 2.1 |
| Salinity | 34.98 – 35.45 |
| Sea surface temperature (°C) | 7.4 – 13.0 |
The Faroe-Shetland Channel OMR is situated to the north of the Scottish mainland between the Shetland Isles and the Faroe Islands (Figure 1). This OMR is the northernmost in Scottish waters and includes the deep Faroe – Shetland Channel which is a rift basin that separates the Scottish and the Faroese continental shelves, reaching depths of over 2,000 m. The bathymetry plays an important role in funnelling ocean currents carrying nutrient-rich water into the region, which support a wide diversity of life. Five different water masses meet in the area, which interact to generate ideal conditions for the boreal ‘ostur’, a type of deep-sea sponge aggregations, to thrive. The channel is also an important corridor for migrating marine mammals, including the fin whale and sperm whale.
Temperature and salinity of the surface waters are governed by their origin in the North Atlantic Ocean. Temperature variability is large due to the seasonal cycle in heat input. There is no such large seasonal variation in the deeper waters, but these have significantly warmed in the last two decades. The circulation is an important pathway for the exchanges between the Atlantic Ocean and Nordic Seas (Greenland – Iceland –Norwegian Seas): at the surface warm, salty water flow towards the Arctic, while at depths deeper than approx. 600 m, cold Arctic-origin water flows southward (see Circulation Assessment). This region is exposed to the large swell from the North Atlantic, which develops because of the long fetch (see also Wave Climate Assessment).
A wide range of geological features occur in the area, including a series of deep-water mud volcanoes known as the pilot whale diapirs as well as iceberg plough marks, prograding wedges and slide deposits which are representative of the West Shetland Margin paleo-depositional system Key Geodiversity Area. Extensive sand wave fields and sediment wave fields are also present in the area.
Productive
The Productive Assessment was undertaken on a sectoral basis with a focus on 2014 - 2018. The Faroe-Shetland Channel is incorporated in the International Council for the Exploration of the Sea (ICES) areas 2a, 4a and 5b. (See fisheries assessment), although the ICES fisheries assessments for area 4a do not tend to include catches from the Faroe-Shetland Channel. For the fisheries sector there were changes over the period 2014 – 2018 (Figure 2).
There is some oil and gas activity in the Faroe-Shetland Channel. Laggan and Tormore are two gas and condensate fields that attracted an investment of £2.5 billion and started production in 2016.
Figure 2: Changes that have taken place in the Faroe-Shetland Channel OMR. The only sector for which activity takes place that could be assessed was that of commercial fishing.
Pressures from human activities
As part of SMA 2020, an assessment of the main pressures from human activities in each of the Scottish Marine Regions and Offshore Marine Regions was undertaken through a MASTS-led workshop. The process and outcomes are presented in detail in the Pressure from Activities section. Five main pressures identified for the Faroe-Shetland Channel OMR ordered as per the MASTS-led Pressure Assessment Workshop were:
| Priority [1] | Pressure (FeAST classification) [2] | Main healthy and biologically diverse components affected [3] | Main contributing FeAST activity /activities to pressure [4] | Associated productive assessments [5] |
|---|---|---|---|---|
| 1 | Physical change (to another seabed type) |
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| 2 | Removal of non-target species (including lethal) |
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| 3 | Removal of target species (including lethal) |
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| 4 | Surface abrasion |
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| 5 | Sub-surface abrasion/penetration |
|
Clean and safe
The assessments cover hazardous substances and marine litter which have the potential to impact on habitats and species as well as being a consequence of human activity. Although sources of litter or contaminants may be local, there are cases when the source is some distance from the impacted area. The main findings for the Faroe-Shetland Channel OMR are:
Hazardous substances
Hazardous substances (polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and heavy metals (Hg, Cd and Pb)) assessments in sediment and biota (fish and shellfish) were undertaken at the scale of the five Scottish biogeographic regions: Atlantic North-West Approaches, Irish Sea (Clyde and Solway), Minches and Western Scotland, Scottish Continental Shelf and Northern North Sea. The Faroe Shetland Channel OMR is in the Atlantic North West Approaches biogeographic region. However, this OMR is not included in the MSS contaminants and biological effects sampling plan, due to difficulties sampling in these deep sea areas. In addition, there may not be suitable sediment and fish sites in this OMR. However, PCBs and PBDEs were previously measured in Scottish deep- water fish (black scabbard, roundnose grenadier and black dogfish) in the Atlantic North West Approaches biogeographic region from 2006 and 2012 (Webster et al., 2014). PCBs and PBDEs were detected, with PCB concentrations being above background but below concentrations where adverse effects could occur, confirming that these contaminants are transported to the Scottish deep-water environment by long range atmospheric transport and accumulate to higher concentrations in species with long lifespans.
Marine litter
Due to the lack of assessment criteria for marine litter, status assessments were not possible. Seafloor litter was assessed at the scale of the biogeographic regions; Faroe- Shetland Channel OMR is included in the Atlantic North West Approaches biogeographic region. The evidence indicates that there are apparent decreases in seafloor litter density over time between 2012 to 2018 inclusive for the Atlantic North West Approaches biogeographic region.
Healthy and biologically diverse
This section summarises the information from the Marine Protected Areas (MPAs) and intertidal and continental shelf habitats assessments from SMA2020. It also provides information from the relevant case studies relating to Priority Marine Features (PMFs), with a focus on habitats. Further work is required to enable assessment at a SMR/OMR scale for most species; this will be included in Scotland’s next marine assessment.
At a SMR/OMR scale for MPAs the focus is on the number of new MPAs, MPAs with new spatial management measures, and MPAs in which spatial management measures are in discussion, as well as recognising monitoring that has been undertaken between 2012-2018. For the marine habitats, the focus is on interpreting the relevant intertidal and continental shelf habitat assessments – biogenic habitats, predicted extent of physical disturbance to the seafloor (BH3) and intertidal seagrass beds. For PMFs, a summary is provided of the changes in our understanding of the habitats of most relevance to the Faroe-Shetland Channel OMR, including changes in distribution and extent.
Marine Protected Areas
Progress in developing the Scottish MPA network
There are 3 MPAs in the Faroe Shetland Channel OMR that contribute to the Scottish MPA network (see Table 1).
Some of these MPAs overlap completely or partially in terms of their spatial coverage and/or the features (habitats, species, etc.) they were set up to help conserve. They are counted as separate MPAs because they have been established under different legislation which influences the way in which they are managed. Also note that there are MPAs that straddle the boundaries between different SMRs/OMRs or in some cases overlap each other.
Where this is the case, these MPAs have been counted as contributing to the MPA network in all of the SMRs/OMRs in which they are present. This means that the total number of MPAs in Scotland cannot be calculated through combining the SMR/OMR totals. Please see the Marine Protected Area assessment which contains statistics for the Scottish MPA network as a whole.
Table 1. Numbers of types of MPAs in the Faroe Shetland Channel OMR that contribute to the Scottish MPA network, including the number of new MPAs introduced since 2012.
|
Type of MPA |
Abbr. |
Total no. of MPAs |
No. of new MPAs 2012-2018 |
|
Special Area of Conservation |
SAC |
1 |
0 |
|
Nature Conservation MPA |
MPA |
2 |
2 |
Progress in Managing MPAs
The progress in implementing management measures for MPAs is summarised in Table 2. This includes information on where spatial management measures are in place and where they are under discussion. It also includes information on the number of MPAs that have been monitored by statutory bodies.
Table 2. Summary of progress in managing Marine Protected Areas in the Faroe-Shetland Channel OMR .
|
Type of MPA |
No. of MPAs with spatial measures in place pre-2012 |
No. of MPAs with new spatial measures in place 2012-2018 |
No. of MPAs with spatial measures under discussion 2012-2018 |
No. of MPAs monitored by statutory bodies 2012-2018 |
No. of MPAs monitored by citizen scientists 2012-2018 |
|
Special Area of Conservation |
0 |
0 |
1 |
1 |
0 |
|
Nature Conservation MPA |
0 |
0 |
2 |
2 |
0 |
For these 3 MPAs (Faroe-Shetland Sponge Belt NCMPA, North-east Faroe-Shetland Channel MPA and Wyville Thomson Ridge SAC), progress is ongoing with fisheries management options being developed.
Progress in Monitoring MPAs
Information on the evidence base used to characterise the offshore MPAs in the Faroe- Shetland Channel OMR and any subsequent monitoring is given in the Site Information Centre web page ( https://jncc.gov.uk/our-work/offshore-mpas/ ) for the following MPAs:
- Faroe-Shetland Sponge Belt MPA,
- Wyville Thomson Ridge SAC,
- North-east Faroe-Shetland Channel MPA.
For links to the MPA Surveys and monitoring reports in the Wyville Thomson Ridge SAC and the North-east Faroe-Shetland Channel MPA, see MPA Monitoring Survey Reports | JNCC - Adviser to Government on Nature Conservation.
Priority Marine Features (PMF)
The assessments focus on individual / grouped habitats and species with a number of case studies reflecting more detailed research and monitoring as outlined in ‘What is assessed’. A key component of an OMR is the number and type of Priority Marine Features (PMFs) present and the associated protected areas. In addition, there is concern about invasive non-native species and the impact that they are having in any particular OMR. With respect to these three aspects, the principal findings of SMA 2020 that are most relevant to the Faroe-Shetland Channel OMR are summarised below.
Number of Priority Marine Features and birds (non-PMF) recorded
The Faroe-Shetland Channel OMR is the location for a range of PMFs as detailed in Table 3.
Table 3. Summary of Priority Marine Features in the Faroe-Shetland Channel OMR .
|
PMFs – grouped habitats and species |
No. of species/habitats recorded |
|
Intertidal and continental shelf habitats |
3 |
|
Fish |
24 |
|
Mammals (regularly occurring) |
13 |
|
Shellfish & other invertebrates |
0 |
|
Seabirds (non-PMF) - breeding |
0 |
|
Seaducks, grebes & divers (non-PMF) – non-breeding |
0 |
- There are 40 PMFs recorded in this region, including a range of fish species, marine mammals and sediment habitats.
- Five different water masses meet in the Faroe-Shetland Channel OMR. These interact with each other and the continental slope thereby creating ideal conditions for the boreal ‘ostur’ type of deep-sea sponge aggregation which is found here and is characterised by high abundances of giant Demospongiae such as Geodia spp.
- The sponges provide shelter for a range of fish species and the pencil urchin Cidaris cidaris as well as providing elevated perches for filter feeders thus enabling them to access food particles in currents.
- Below 800 m, the muddy seabed is home to species that can tolerate the cooler arctic-influenced waters, such as deep-sea bristleworms (polychaetes).
- The bivalve ocean quahog (Arctica islandica), an OSPAR Threatened and/or Declining species, is found usually buried in sand or muddy-sand. This species regularly lives for over 100 years, but life spans of 400 years have also been reported for this species making it one of the longest living creatures on earth.
- There are two distinct sedimentary communities found in the region separated by their depth distribution and their sediment characteristics. These two communities are dominated by contrasting polychaete families.
Climate change
There is good evidence that climate change is driving changes in the physical, chemical and biological conditions of the marine environment but the current evidence base limits the ability to draw conclusions at the scale of the individual marine regions, including the Faroe-Shetland Channel OMR. This is a combination of the lack of comprehensive spatial coverage of key monitoring programmes, the relatively short time series, and the complex linkages of climate change impacts in the marine environment.
Increasing concentrations of atmospheric greenhouse gases have caused more energy to be trapped within the Earth’s atmosphere, land and ocean. Approximately 90% of this excess energy has been absorbed by the ocean, resulting in warming ocean temperatures (see Temperature assessment and Climate change Sea temperature assessment).
The increasing concentration of carbon dioxide, one of these greenhouse gases, has the additional consequence of driving a reduction in the pH of the ocean, a process known as ocean acidification (see Ocean acidification assessment and Climate change Ocean acidification assessment).
Mean sea level is rising due to increased contributions of freshwater from melting of land-based ice (glaciers and the polar ice sheets) and due to thermal expansion of water (see Sea level and tides assessment and Climate change Sea level assessment).
The warming temperatures also result in lower oxygen concentrations due to fact that warm water holds less oxygen and changes in stratification further influence oxygen concentrations (see Dissolved oxygen assessment and Climate change Dissolved oxygen assessment). Together with increased metabolic rates in organisms resulting in increased respiration, oxygen depletion has a severe impact on marine organisms due to the impact on metabolic processes.
These changes in the physical environment are also having an impact on marine life, such as changes to their metabolism, changes in seasonality and the timing of events in natural cycles, and changes in their distribution. These changes have consequences for the growth, survival and abundance of species, including those of commercial importance or critical to conservation objectives.
At present, most of these impacts are assessed at scales greater than marine regions. The Community Temperature Index combines species temperature affinity and their abundances. This index has the potential to inform how communities change due to climate change. An example of changes in the Community Temperature Index from bottom-living fishes can be found in the Fish section within Biological Impacts of Climate Change, where more information on other impacts in marine food webs can be found (such as seabirds and marine mammals) on large regional scales in Scottish waters.
Sea surface temperature in the Faroe-Shetland Channel OMR has increased since 1870 by 0.04 °C per decade on average. The rate of increase has not been constant, and in the last 30 years (1988-2017), the rate of change in temperature was +0.21 °C per decade.
Summary
The Faroe-Shetland Channel OMR has seen a 37% increase in the value of the fisheries catch over the five years from 2014-2018.
The five main pressures affecting the OMR are Physical change, Removal of non-target species, Removal of target species, Surface abrasion, Sub-surface abrasion/penetration. Other pressures identified are Death or injury by collision above water, Death or injury by collision below water, Genetic modification and translocation of indigenous species, Hydrocarbon and PAH contamination, Introduction of light or shading, Introduction of microbial pathogens, Introduction or spread of non-indigenous species, Litter, Reduction in availability or quality of prey, Siltation rate changes (heavy), Siltation rate changes, Synthetic compound contamination, Underwater noise Visual disturbance and Water clarity change.
No contaminant (i.e. PAHs, PCBs, PBDEs and heavy metals) samples were collected from the OMR due to difficulties of sampling. In the wider Atlantic North-west Approaches biogeographic region the evidence shows there is a decrease in sea-floor litter density between 2012-2018.
Two new MPAs were designated between 2012-2018, and no new spatial management measures were put in place. Spatial fisheries management measures are under discussion for three MPAs. Three MPAs were monitored by statutory bodies during the period 2012-2018.
In the last 30 years sea temperature has risen by 0.21 °C per decade.