| Activity |
Hazard Evaluation |
Notes on Proposed Protected Area |
|
Present |
Future |
|
| Depressed fish abundance |
Important |
Important? |
Influences seabird breeding productivity and
adult survival rates. Sandeels are of primary importance to Fair Isle seabirds. Sandeels
are short-lived and therefore subject to pronounced natural fluctuations. Reductions could
be brought about by overfishing, or by reducing catches of predatory fish and thus
increasing the sandeel biomass consumed by fish. A decline in sandeel stocks is thought to
have caused the fall in breeding productivity of a number of seabird species during the
late 1980s; high post-fledging mortality was also evident. Marked reductions in abundance
of other fish species have been widely reported by islanders. However, insufficient
scientific research into fish stocks has been conducted to quantify the level of decline. |
|
|
|
|
| Changes in fish community composition |
Important |
Important? |
Some seabird species have a high reliance on
particular fish species during the breeding season. At Fair Isle, changes in fish
communities are probably only relevant when they include reduced sandeel abundance.
Studies at Fair Isle and elsewhere indicate that in years of low sandeel availability,
other fish are brought to chicks but that loads are smaller, foraging time is greater and
the calorific value of prey items is much lower (see Appendix 2). Only a few species (eg
gannet) seem able to switch successfully to other prey species. |
|
|
|
|
| Shore collection |
Trivial |
Trivial? |
Large-scale collection of molluscs may limit
food supply for some species. Historically, limpets were taken extensively as bait for
long-lines. Currently, shore collections are rare and limited in extent. The level of
collection is not anticipated to rise. |
|
|
|
|
| Aquaculture |
Nil |
Nil? |
None at present. If introduced, possible
effects on species such as eider and shag through predator controls. Implications for
birds of accumulation of organic waste and the use of chemicals for fish husbandry are
unknown. A low-key study was undertaken by the NTS to investigate the possibility of
installing salmon cages in one or more bays. This concluded that the Isle is unsuitable,
for logistical and environmental reasons. |
|
|
|
|
| Changes in size distribution within fish
stocks |
Important |
Important? |
Some seabird species select prey in a certain
size range and would therefore be affected by changes in the size distribution within fish
stocks. Most Fair Isle seabirds actively select older (larger) sandeels. Some species
require a variety of age classes for different aspects of their breeding biology (Monaghan
et al 1991). There is no evidence to suggest that fisheries are currently
important in altering the size composition of sandeels available to Fair Isle seabirds (P.
Harvey, in litt). |
|
|
|
|
| Damage to benthos |
Important |
Important? |
Fishing for clams and the introduction of
rockhopper trawls have caused damage to the seabed in the past. This has included loss of
biota (eg apparently 'barren' sand occurring in areas previously occupied by
dead-man’s fingers and red seaweeds). Sand and fine gravel – the predominant
substrate – is preferred by sandeels at spawning and as a refuge to most age classes
at all periods of the year; damage to benthic communities could therefore have indirect
effects on seabirds. (A study at Loch Ewe found that experimental scallop dredging
destroyed large numbers of sandeels burrowing in the sand, as well as molluscs,
echinoderms and crabs (Eleftheriou and Robertson, 1992).) |
|
|
|
|
| Net and line mortality |
Unknown |
Small? |
Implications of net fisheries in the area
unknown. Seabird mortality due to drowning in fishing nets has been recorded.
Tangle/monofilament nets are not currently in use: experience elsewhere suggests that the
hazard evaluation may need to be revised if their use was introduced, depending on the
depth and mesh size proposed. No line fisheries are currently in operation. |
| 3.2 Shipping and navigation |
|
| Accidental discharges – oil |
Important |
Important? |
There have been no recorded incidents of
accidental spills affecting seabirds. However, the MV Braer incident, and the
Isle’s record of over 100 shipping accidents in the last 250 years demonstrates the
vulnerability of its marine environment to this hazard. |
|
|
|
|
| Deliberate discharges –
oil |
Small |
Small? |
Direct evidence of deliberate discharges (oil
on beaches and oiled seabirds) is relatively unusual, though a beach contaminated with an
estimated half-ton of tar balls in February 1996 demonstrated that Fair Isle is not
entirely immune from this hazard. |
|
|
|
|
| Accidental discharges – chemicals |
Unknown |
Unknown |
A range of dangerous chemicals is carried by
maritime traffic. There have been no recorded incidents affecting seabirds but the Isle is
vulnerable to accidental discharge for the same reasons that put it at risk to oil
pollution. |
|
|
|
|
| Deliberate discharges – chemicals |
Unknown |
Unknown |
Not known to occur, but see 3.3. |
|
|
|
|
| Disturbance – shipping |
Nil |
Nil? |
Commercial vessel traffic keeps well away from
Fair Isle shores. Therefore, disturbance to breeding colonies is rarely, if ever, an
issue. |
|
|
|
|
| Maintenance dredging |
Nil |
Trivial/Nil? |
Potential effect on benthos and contamination
of sediments. Any future maintenance dredging is expected to be small-scale and very
restricted (eg a small strip immediately behind the North Haven breakwater). |
|
|
|
|
| Capital dredging |
Nil |
Nil? |
No operations are planned or expected. |
|
|
|
|
| Alien species |
Trivial |
Important? |
Accidental introductions have potential
knock-on effects for birds. The only alien species to be recorded on Fair Isle is a single
American slipper limpet in the late 1980s. This species smothers other sedentary molluscs,
and is considered a pest to commercial shellfish beds in the English Channel. The
potential arrival of fishing boats from distant ports means that Fair Isle may not be
immune to more significant arrivals of damaging alien species. |
| 3.3 Water quality and pollution control |
| Plastic – entanglement |
Trivial/ Small |
Trivial/ Small? |
Considerable amounts of litter are washed up
on shore. Further accumulations of litter following annual beach clean-ups demonstrate
that the problem is constant. Plastic entanglement of birds is widespread, although the
impact on populations is negligible. Most frequent occurrences include seabird chicks
entangled in materials incorporated into the nest. Discarded polypropylene fish netting is
common and frequently entraps gannets and seals at sea. |
|
|
|
|
| Plastic – ingestion |
Unknown/Small? |
Small? |
Rare instances of ingestion have been
recorded. No data on impact (presumed low). |
|
|
|
|
| Oil and other lipophilic substances |
See 3.2 |
|
|
|
|
|
|
| Glycol and other corrosion inhibitors |
Nil/Trivial |
Trivial? |
There is a constant potential hazard, but
incidents are infrequent and localised. |
|
|
|
|
| Pesticides |
Trivial |
Trivial? |
Agriculture is extensive, with low chemical
input. The origins of many pesticides are likely to be outwith the Northern Isles. Studies
of organochlorine insecticides in samples of fulmar, shag and guillemot eggs in
1980–81 (part of a UK-wide survey) showed very low levels of DDE and the eggs were
largely free of dieldrin residues. The levels and frequency were among the lowest of any
UK sample. |
|
|
|
|
| Polychlorinated biphenyls |
Trivial |
Trivial? |
Prohibitions on use should make the risk from
PCBs small. The 1980–81 tests showed only traces of PCBs in some eggs (and nil in
others). Levels and frequency were among the lowest in the UK. Contamination of sediments
has not been identified as an issue in this area |
|
|
|
|
| Heavy metals |
Unknown/Trivial? |
Important? |
The 1980–81 tests detected mercury at
very low levels in all eggs and cadmium in one. The levels and frequency for each were
amongst the lowest of any UK sample. The levels of other heavy metals are unknown.
Contamination of sediments has not been identified as an issue in this area. The oil
company Kerr-McGee Ltd plan to undertake exploratory drilling in block 7/16 (40 km east of
Fair Isle) from September 1997. The water-based drilling muds to be used contain a
cocktail of toxic heavy metals and other pollutants (JLOGC, 1996; D. Taylor,
Kerr-McGee Ltd, pers comm). Recent studies in Norwegian waters indicate that
toxic effects are not restricted to a small area and significant perturbations in
community structure have been detected many kilometres from platforms (JLOFC, 1996;
Olsgard & Gray, 1995). |
|
|
|
|
| Radionuclides |
Unknown |
Small? |
The nearest nuclear facility is at Dounreay,
Highland. Discharges of radioactive material are made from this facility, which was
recently refused permission for an increase by SEPA. Radionuclides from that source are
unlikely to be an issue. |
|
|
|
|
| Nutrient enrichment |
Nil/Trivial |
Nil/Trivial? |
Agriculture is extensive, with low chemical
input. None of the streams running to the sea show any signs of nutrient enrichment. |
|
|
|
|
| Thermal pollution |
Nil |
Nil? |
The nearest oil-fired power station is at
Lerwick, Shetland (80 km north) and the nearest nuclear power station at Dounreay (150 km
south-west). |
|
|
|
|
| Ammunition dumps |
Unknown |
Trivial? |
None known in the immediate area, though an
ammunition dump lies west of Orkney, and there was an isolated incident in the 1970s of a
torpedo trawled to the surface 16 km south of Fair Isle. Impacts on seabirds unlikely. |
| 3.4 Mineral and energy extraction |
| Oil and gas – exploration |
Nil |
Important? |
The oil company Kerr-McGee Ltd plan to
undertake exploratory drilling in block 7/16 (40 km east of Fair Isle) from September
1997. Licences for exploration are held by the same company for three adjacent blocks.
This area is important to seabirds and sea mammals virtually throughout the year, and
contains an important spawning and/or nursery area for fish species (especially haddock). |
|
|
|
|
| Oil and gas – production |
Nil |
Important? |
Production plans will be determined by the
results of Kerr-McGee's present operations. The interest of other operators in adjacent
blocks would presumably be high if this exploratory drilling demonstrated substantial
reserves of oil. |
|
|
|
|
| Oil and gas – pipelines |
Nil |
Important? |
The means of transporting any oil produced,
whether by pipeline or vessel, are currently unknown. |
|
|
|
|
| Aggregate extraction |
Nil |
Small? |
Aggregate extraction has never been undertaken
and there are no current plans to do so. Depth is a limiting factor, but may be less so as
technology improves and current resources are depleted. The sea bottom substrate in Fair
Isle waters is composed of extensive sand and gravel plains, so could conceivably become a
potential aggregate source in the future. However, the probability of extraction is very
low. |
| 3.5 Coastal development |
|
| Land claim |
Nil |
Nil? |
The coastline is not suitable for land claim. |
|
|
|
|
| Discharges from industry |
See 3.3 |
|
|
|
|
|
|
| Direct impact on wildlife |
Trivial |
Nil? |
A breakwater and pier extension were
constructed in 1992–93. This contributed to habitat change in the enclosed area of
North Haven (by changing the site from moderately exposed to sheltered). A decline in
breeding fulmar numbers and productivity within the North Haven has been associated with
the development (Riddington, et al 1994–96). |
| 3.6 Direct human exploitation of birds |
| Harvesting – Food |
Nil |
Nil? |
Historically, seabirds were harvested as an
integral part of the human diet. (The seabird populations are still seen by the Fair Isle
community as an economic resource, but in promoting tourism.) |
|
|
|
|
| Harvesting – Feathers |
Nil |
Nil? |
|
|
|
|
|
| Harvesting – Museums |
Nil |
Nil? |
|
|
|
|
|
| Culling for management |
Nil |
Nil? |
Control of large gulls has not been necessary
(apart from isolated individuals causing damage at lambing). Large gulls, skuas and Arctic
terns are a safety issue around the airstrip, but control measures are expected to involve
encouraging birds to move to other sites rather than culling. |
| 3.7
Recreation |
|
| Disturbance |
Trivial |
Trivial? |
Recreation is only ever likely to cause major localised
disturbance. Regular boat trips to view seabird colonies from the sea come close to
certain colonies, but studies have shown than the only disturbance is to non-breeding
'loafing' birds. Recreational landings would cause disturbance, but the logistical
difficulties posed by swell and submerged rocks make such landings unlikely. Recreational
activities on land are rarely an issue. |
|
|
|
|
| Coastal development |
Nil |
Nil? |
Not expected, and adequate controls already in
place through existing SPA regulations. |
|
|
|
|
| 3.8
Other issues |
|
| Research and monitoring |
Trivial |
Trivial? |
Fair Isle has a long history of research and
monitoring. Fair Isle Bird Observatory, established in 1948, holds one of the longest
uninterrupted seabird data sets in the world. Since 1986, the bird observatory has
contributed to JNCC’s UK Seabird Monitoring Scheme. Other monitoring includes migrant
birds and (in recent years) non-avian fauna and flora. All researchers follow a code of
conduct to minimise disturbance, of particular importance when working in seabird
colonies. |
|
|
|
|
| Disease |
Small |
Small/ Important? |
Despite the dense seabird colonies, no large
scale epidemics known. Localised outbreaks of Puffinosis have been recorded, notably
amongst fulmars in the 1970s. Red tides are rare; a combination of low sea temperatures
and very strong tidal currents may ensure that they do not develop or are short-lived. |
|
|
|
|
| Disturbance – aerial
traffic |
Nil |
Nil? |
Regular air traffic includes an almost daily
commercial service in summer, passing commercial traffic between Aberdeen and Shetland,
coastguard and lighthouse helicopters, and private planes. A systematic study in 1973
demonstrated that a small aircraft passing within 250 m of the seabird colonies
caused no disturbance to breeding birds. Subsequent observations suggest that the current
types and level of air traffic cause no harmful disturbance. |
