Strategic Environmental Assessment of the Former White Zone
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Strategic Environmental Assessment of Former White Zone Volume 2 - Synthesis of Environmental Information CONTENTS 1 INTRODUCTION 5 2 PHYSICAL AND CHEMICAL ENVIRONMENT 7 2.1 Meteorology 7 2.2 Bathymetry and Topography 7 2.3 Hydrography 11 2.3.1 Data Sources 11 2.3.1.1 Measurement Programmes 11 2.3.1.2 Circulation Models of the North Atlantic 14 2.3.2 Hydrographic Overview 15 2.3.2.1 Wyville Thomson Ridge 15 2.3.2.2 Faroe Shetland Channel 19 2.3.2.3 Northern North Sea/Southern Norwegian Sea 21 2.4 Solid Geology 22 2.5 Sediments 22 3 BIOLOGICAL ENVIRONMENT 25 3.1 Plankton 25 3.1.1 Primary Production 25 3.1.2 Zooplankton 26 3.2 Benthos 29 3.2.1 Data Sources 29 3.2.1.1 Historic and Oilfield Surveys 29 3.2.1.2 Regional Surveys 31 3.2.2 Benthic Communities 33 3.2.2.1 Northern Rockall Trough 33 3.2.2.2 Wyville Thomson Ridge 33 3.2.2.3 Faroe Bank Channel 34 3.2.2.4 Faroe Shetland Channel 34 3.2.2.5 North Sea Fan 34 3.2.3 Discussion 35 3.2.3.1 Macrofaunal Communities 35 3.2.3.2 Phytodetritus 38 August 2000 Page 1 CONSULTATION DOCUMENT Strategic Environmental Assessment of Former White Zone Volume 2 - Synthesis of Environmental Information 3.2.3.3 Sponge Communities 38 3.2.3.4 Darwin Mounds 39 3.2.3.5 Lophelia pertusa and Other Cold Water Corals 40 3.2.3.6 Gas Hydrates 42 3.3 Fish 42 3.3.1 Pelagic Species 42 3.3.2 Demersal Species 44 3.3.2.1 Faroe Shetland Channel and Norwegian Sea 46 3.3.2.2 Rockall Trough (500 – 1000m) 46 3.3.3 Demersal Shark and Ray Species 47 3.3.3.1 Rockall Trough 47 3.3.3.2 Faroe Shetland Channel 48 3.3.4 Pelagic Sharks 48 3.4 Seabirds 49 3.4.1 Data Sources 49 3.4.2 Distribution, Importance and Seasonal Variation 49 3.4.2.1 North of Shetland 51 3.4.2.2 Faroe Shetland Channel 51 3.4.2.3 Wyville Thomson Ridge 51 3.4.3 Species Accounts 51 3.4.4 Vulnerability to Oil Pollution 58 3.4.4.1 North of Shetland 58 3.4.4.2 Faroe Shetland Channel 58 3.4.4.3 Wyville Thomson Ridge 59 3.4.4.4 Data Accuracy 59 3.5 Marine Mammals 59 3.5.1 Data Sources 59 3.5.2 Species Accounts 61 3.5.3 Discussion 73 4 EXISTING ACTIVITIES 77 4.1 Fishing 77 4.2 Shipping 79 4.3 Oil and Gas 79 CONSULTATION DOCUMENT Page 2 August 2000 Strategic Environmental Assessment of Former White Zone Volume 2 - Synthesis of Environmental Information 4.4 Telecomms 80 4.5 Military 80 5 THE COASTAL ENVIRONMENT 81 5.1 Coastal Conservation Overview 81 5.1.1 Shetland 81 5.1.2 Orkney 84 5.1.3 Western Isles 87 5.1.4 North Highland Coast 90 5.1.5 The Faroes 92 5.2 Uses of the Coastal Zone 95 5.2.1 Sea Coastal Users – Shetland 95 5.2.1.1 Fishing 95 5.2.1.2 Fish Processing 97 5.2.1.3 Salmon Farming 97 5.2.1.4 Shellfish Farming 98 5.2.1.5 Tourism and Recreation 99 5.2.1.6 Other Industry and Coastal Users 100 5.2.2 Sea Coastal Users – Orkney 101 5.2.2.1 Fishing 101 5.2.2.2 Fish Processing 104 5.2.2.3 Salmon Farming 104 5.2.2.4 Shellfish Farming 105 5.2.2.5 Tourism and Recreation 105 5.2.2.6 Other Industry and Coastal Users 107 5.2.3 Sea Coastal Users – Western Isles 108 5.2.3.1 Fishing 108 5.2.3.2 Fish Farming 111 5.2.3.3 Shellfish Farming 111 5.2.3.4 Tourism and Recreation 112 5.2.3.5 Other Industry and Coastal Users 113 5.2.4 Sea Coastal Users – North Highland Coast 114 5.2.4.1 Fishing 114 5.2.4.2 Salmon Farming 116 5.2.4.3 Shellfish Farming 117 5.2.4.4 Tourism and Recreation 117 5.2.4.5 Other Industry 118 August 2000 Page 3 CONSULTATION DOCUMENT Strategic Environmental Assessment of Former White Zone Volume 2 - Synthesis of Environmental Information 5.2.5 Sea Coastal Users – Faroe Islands 119 5.2.5.1 Fishing 119 5.2.5.2 Aquaculture 121 5.2.5.3 Tourism and Recreation 121 5.2.5.4 Other Industry and Coastal Users 122 6 REFERENCES 125 CONSULTATION DOCUMENT Page 4 August 2000 Strategic Environmental Assessment of Former White Zone Volume 2 - Synthesis of Environmental Information 1 INTRODUCTION The former White Zone comprises the area located along the median line between the UK and Faroese continental shelves. Following lengthy negotiations concerning the geographical definition of the median line, agreement was reached between the UK and Faroese Governments on 18 May 1999, enabling both countries to proceed with hydrocarbon licensing in respective territorial waters. This document provides a Synthesis of Environmental Information, in support of a Strategic Environmental Assessment of the UK sector of the former White Zone. The Synthesis contains a comprehensive review of available information concerning the physical, chemical, biological and socio-economic environment of the former White Zone and adjacent coastal waters and coastlines. The Synthesis also provides sources and references for available data, and identifies significant gaps in data coverage. The geographical area covered by the Synthesis includes the former White Zone (defined as the area between existing licensed acreage on the UKCS and the median line), including parts of the Faroe Shetland Channel, Faroe Bank Channel, Wyville Thomson Ridge and northern Rockall Trough (Figure 1) together with the coastal waters and coastlines of the Faroe, Shetland, Orkney and Western Isles and mainland of northern Scotland. Figure 1 – Former White Zone August 2000 Page 5 CONSULTATION DOCUMENT Strategic Environmental Assessment of Former White Zone Volume 2 - Synthesis of Environmental Information This page is intentionally blank CONSULTATION DOCUMENT Page 6 August 2000 Report to the Department of Trade and Industry Strategic Environmental Assessment of the Former White Zone Volume 2 – Synthesis of Environmental Information Consultation Document AUGUST 2000 Prepared by Hartley Anderson Limited [email protected] Strategic Environmental Assessment of Former White Zone Volume 2 - Synthesis of Environmental Information 2 PHYSICAL AND CHEMICAL ENVIRONMENT 2.1 Meteorology The former White Zone has a generally mild, maritime climate resulting from prevailing south-westerly winds and the warming influence of the Atlantic Continental Slope Current. The weather is strongly influenced by two semi-permanent weather systems, a low pressure region over Iceland and a high pressure area over the Azores. When these are in place, a stream of secondary depressions pass between the two in a general east or north-east direction. These depressions occur with a similar frequency throughout the year; however, they are most intense in winter months when gales are more common. The area has characteristically changeable weather patterns caused by the variability in positions of warm and cold fronts and development of anticyclones and depressions. Polar depressions from the Norwegian Sea are characterised by a relatively small circulation of intense, squally showers (of snow in winter). The area experiences frequent low cloud with periods of extensive rain and drizzle. Sea fog is more common in the summer and relatively uncommon during the winter months. Winds in this area of the north Atlantic can occur from any direction, but predominant winds tend to be from the south-south-west, west-south-west and west. Less predominant, but displaying a more uniform distribution are winds from the east-north-east and east. During spring (April to June), the area is characterised by a uniform wind distribution, with east- south-east, north-north-west, north and north-north-east winds being predominant. During the rest of the year (from July to March) south-south-west, west-south-west and north winds occur with a percentage frequency of 32%. Marshall (1997) provides wind roses which summarise wind direction and speed data for the UK and Faroes. There is a significant seasonal variation in wind speed. Annual mean wind speeds tabulated by Marshall (1997) for Lerwick and Tórshavn are between 11 and 15 knots (moderate breeze). In winter (November to March), monthly mean wind speeds are between 12 and 17 knots but are generally less in the summer months ranging from 8 to 13 knots. Gales are common in winter, occurring on 8 days per month in January and December, and calm conditions are rare throughout the year. 2.2 Bathymetry and Topography The former White Zone area is variable in bathymetry and topography (see Figures 1 and 2 and Stoker et al. 1993 and Britsurvey 2000) with, from the north, the primary features of the area being the North Sea Fan, the Faroe Shetland Channel, the Faroe Bank Channel and the Wyville Thomson Ridge. In the broad part of the area to the north of 62°N, the gently sloping North Sea Fan is adjacent to the Norwegian Sea abyssal plain. Water depths are greatest in the north of this area with a maximum of around 2400m, decreasing to around 900m in the south-east of the surveyed area. The UK-Faroes boundary crosses the lower flank of the Fugloy Ridge, the east facing extension of the Faroes shelf, after which it traverses the Faroe Shetland Channel to approximately its southern extremity.