THREATS TO THE COASTAL ECOSYSTEMS OF THE MORAY FIRTH
Exploitable oil reserves were discovered in the North Sea in the late 1960's and since then the extraction and processing of oil has boosted the economy of the whole of the north east of Scotland. In the Moray Firth, the Beatrice oil field lies 22km off the coast and has been operating since 1976. It covers an area of around 23km2, the oil is 2,100m below the sea bed and about 8,000 tonnes of oil is produced each day.
Oil from the Beatrice field is processed at an oil terminal at Nigg, on the Cromarty Firth and it is transported there by pipeline on the sea bed. Tankers then take the refined oil around the world - the deep and sheltered inlets of the firth allow easy access for these tankers. Oil platforms and pipelines are built and repaired at sites around the inner Moray Firth, such as at Invergordon.
The economic boost provided by the oil industry comes at a price to the natural environment of the Moray Firth. Oil can cause pollution, most sensationally if spilled from tankers, but leaks from pipelines, pollution from shore-based sources and rubbish dumped from oil platforms are more of a threat to the environment. The land-based refineries and yards are built on reclaimed land and often in areas important to wading birds.
So far, no major environmental damage has resulted from oil pollution in the Moray Firth. The oil and shipping industries work hard to minimise the risks to the environment, with safe working practices, regular equipment inspections and contingency plans in the event of an oil spill. For examples see the Shoreline Protection Strategy Plan and the Guidelines on Cetaceans in the event of an oil spill.
With about 120,000 people living, working and having fun around the Moray Firth, we are bound to have an effect on the health of the firth's environment.
Towns around the coast discharge waste into the sea. Household waste, including waste water from sinks, washing machines, baths and toilets, run-off from roads as well as industrial waste, all goes into a sewage system.
Much of our sewage ends up in the sea in a raw - or undertreated - state. It can contain human waste products, metal compounds, dyes, solvents and oil-based products.
Sewage contaminates our beaches, littering them and making the water unfit for swimming in - sewage pollution poses a health risk and is responsible for gastro-intestinal diseases and respiratory infections in bathers. Filter feeding shellfish such as mussels and oysters accumulate bacteria and toxins in their tissues and if people eat contaminated shellfish, this can result in serious food poisoning.
Even agricultural practices on fields away from the coast can affect the marine environment. Fertilizers and pesticides that farmers spray on their fields can run-off into rivers and drains and make their way to the sea.
Extra nutrients in the sea supplied by fertilizers can cause a bloom in plants and seaweeds. Phytoplankton blooms can be toxic as many of the tiny algae produce small quantities of toxins as a deterrent to would-be grazers. Seaweeds, such as a species called Enteromorpha, grow prolifically on mudflats, choking the mud and starving its inhabitants of oxygen. This in turn can affect wading birds that depend on these creatures for food.
When we throw away rubbish or drop litter, it doesn't just disappear - it stays in the environment for a long time, in some cases for even longer than ourselves! For example, aluminium cans last for up to 100 years, while glass lasts for one million years and plastic never decays. Even so-called 'bio-degradable' items take time to decay - banana skins and orange peel can last for up to two years.
As well as being unsightly, litter also poses a problem to marine wildlife. Sea birds are often found strangled by plastic packaging, marine mammals may be injured by ingesting plastic fragments. Discarded fishing nets continue to 'fish' the sea long after they've been dumped from boats, entangling fish but also marine mammals which then drown.
Much of the effluent discharged from coastal whisky distilleries into the sea is now treated after recommendations made to SERAD. Shores that had been most affected in 1970 were re-examined and effects were still found to be present but at a reduced level, with the ecosystem communities in a recovery stage at Findochty. It is reported that Buckie remains the most polluted site on the south coast of the Moray Firth.
Landclaim has taken place historically on several sites within the Moray Firth resulting in the loss of intertidal habitats. This has occurred in parts of Nigg Bay in the Cromarty Firth for oil related activities. Landclaim continues in part of the Longman Bay in the Inverness Firth where a rubbish disposal landfill site is situated on the foreshore. Landclaim was proposed in the Beauly Firth in the 1980's for agricultural purposes.
The ability of common cordgrass (Spartina anglica) to rapidly colonise open mudflats has been exploited by man for coastline stabilisation and landclaim. Natural colonisation has also led to deterioration of mudflat communities through decreased species and habitat diversity.
Damage results from a variety of recreational activities on a range of coastal and intertidal habitats, depending on their fragility. Within the Moray Firth examples include uncontrolled recreational use of sand-dune systems on the Dornoch Firth resulting in habitat destruction from bike riding, horse riding, fires and turf cutting of saltmarsh areas. Most of these activities are uncontrolled and very difficult to regulate. Areas such as part of the Dornoch Firth Links have been altered by the golf course and caravan site.
Commercial exploitation of shellfish may disturb or destroy intertidal habitats although effects are expected to be site specific. Cockle fishing using modified potato harvesters on the foreshore has occurred at Inver Bay in the Dornoch Firth and Culbin Sands and has been proposed in other areas. The exact impact of this fishing method is unknown, although at intensive levels of exploitation the effects on the cockles, non-target species living in the sands and mud and the bird population is likely to be detrimental. Areas where eelgrass (Zostera species) is present may be particularly vulnerable to cockle harvesting and dredging methods.
The construction of various developments and communication associated structures have affected some coastal and intertidal habitats. For example, the construction of a road embankment in the early nineteenth century at the head of Loch Fleet sealed off part of the upper estuary. This area has now developed into a mixture of aldercarr, woodland and open fen, with saline lagoons.