Marine science
The Water Framework Directive (WFD) requires SEPA's marine
science function to undertake monitoring to determine whether
transitional (estuary) and coastal water bodies are achieving good
status.
Coastal waters
The WFD defines coastal waters as:
"…surface water on the landward side of a line, every point of
which is at a distance of one nautical mile on the seaward side
from the nearest point of the baseline from which the breadth of
territorial waters is measured, extending where appropriate up to
the outer limit of transitional waters." Article 2 (7)
According to the WFD, the ecological status of coastal waters
must be classified out to one nautical mile (nm) from the
baseline. However, the Scottish Government has extended this
limit out to 3 nm for Scotland's waters.
Transitional waters
The WFD defines transitional waters (estuaries) as:
"…bodies of surface water in the vicinity of river mouths which are
partly saline in character as a result of their proximity to
coastal waters but which are substantially influenced by freshwater
flows." Article 2 (6)
Fifty transitional water bodies and 450 coastal water bodies
have been identified in Scotland.
Transitional and coastal water body
types
A typology for coastal and transitional waters for the UK and
Ireland has been developed through a Scotland and Northern Ireland
Forum For Environmental Research (SNIFFER) funded project.
The contract was awarded to a consortium of agencies/consultants
led by the Centre for Environment, Fisheries and Aquaculture
Science (CEFAS) in conjuection with the Joint Nature Conservation
Committee (JNCC), British Geological Society, Institute of
Estuarine and Coastal Studies and Aqua-Fact.
Click here to see a map of Scottish
transitional and coastal water bodies.
Monitoring in transitional and coastal
waters
The WFD requires SEPA to undertake monitoring to determine
whether water bodies are achieving good status. For
transitional and coastal waters this monitoring and analysis will
be undertaken by the marine science function. The quality elements
for the classification of ecological status in transitional and
coastal waters are:
- Biological elements (eg composition, abundance and biomass of
phytoplankton in transitional and coastal waters).
- Hydromorphological elements supporting the biological
elements(eg structure of the inter-tidal zone in transitional and
coastal waters).
- Chemical and physio-chemical elements supporting the biological
elements (eg transparency, thermal conditions, salinity,
oxygenation conditions and nutrient conditions in transitional and
coastal waters; specific pollutants (pollution of other substances
identified as being discharged in significant quantities into the
body of water) in transitional and coastal waters).
Surveillance monitoring is intended to:
- supplement and validate the characterisation process
- assess long-term changes due to natural conditions and
widespread anthropogenic activity
The results of the surveillance monitoring programme can be used
for classification purposes, and therefore to supplement the
operational monitoring network.
The surveillance monitoring network will consist of sites across
the gradient of ecological impact, including a network of impacted
sites to validate specific pressure-impact risk assessments .
In addition to validating risk assessments and monitoring long-term
change, the
CIS guidance 
states that
sufficient surveillance sites are required to allow an assessment,
within each sub-catchment, of the overall surface water status.
The proposed distribution of surveillance sampling sites,
excluding lagoons, is shown on Figure 1 and comprises 25 sites.
Further information on SEPA's marine science function can be
found in the Scotland's environment
section.