IN THIS SECTION
Living things in the Harbour
People & the Environment
Land, water and air
Maps
Habitats
RELATED LINKS
Land, water and air
Water Quality and the Stream Watch Project
Holiday makers at East Head
In 2003 all the water of Chichester Harbour passed the minimum quality standards and many areas were better than that.
Water quality is also important so that the shellfish harvested from the Harbour are safe to eat.
A recent study by the Environment Agency suggested that 92% of the substances (nutrients) affecting water quality enter the Harbour from the Solent. When nutrient levels rise, there is excessive growth of algal weed which smothers environmentally sensitive saltmarsh and mudflat and causes problems for sailors as well as smelling unpleasant when it starts to decompose.
Two nutrients in particular affect algal growth, phosphates and nitrates. These are normally present in the environment but pollution can lead to unnaturally high levels.
The biggest contribution to nitrate pollution in the harbour is probably from agriculture whereas domestic waste water is thought to be the main cause of raised phosphate levels.
Working in the stream
The Stream Watch Project
Every month since October 2004 six freshwater streams that flow into Chichester Harbour have been tested for water quality.
Pupils from local schools, both primary and secondary, have taken part in this project helping to collect data about the streams.
This is a cross-curricular project with a Science and Geography focus.
The pupils who have taken part in the project have had fun exploring the streams and examining the creatures that live in them as well as learning about the scientific techniques of water testing. It is an opportunity for older pupils to take part in a serious field study activity that would contribute towards GCSE/A-level course work and case study examples in exam papers. All the data collected is published on the main Conservancy website.
For more details click here.
Stream watch cross section
Sewage treatment
A potential threat to water quality comes from point sources such as sewage treatment works.
Southern Water is spending large amounts of money on improving wastewater treatment, but pollution from sewage can still be a problem partly due to the rising population in the area but also due to drought, which results in less dilution of the discharge from treatment works. Many sewage treatment works are currently still not able to reduce phosphate and nitrate levels in wastewater.
Sewage is the biggest contaminant now of surface water, closely followed by oils & fuels. Other common pollutants include inert materials, waste materials, chemicals and agricultural materials and wastes.
3 sewage treatment works discharge into the Harbour.