B5. Pressure from pollution

B5b. Marine pollution

 

Type: Pressure indicator

 

Indicator Description

The indicator shows the combined input of six of the most hazardous substances to the UK marine environment.  The indicator is based on levels of five heavy metals (cadmium, mercury, copper, lead and zinc) and one organic compound (lindane).  Pollution in the marine environment from these six substances should decrease to levels that are non-detrimental by 2020.

 

Summary

 

The combined inputs of all six hazardous materials into marine environments have shown a long term decrease of 80% since 1990.  Inputs of five of these substances show decreases since 2011, however the input of copper has increased by 1% in the short term.

 

Figure B5bi. Combined input of hazardous substances to the UK marine environment, as an index of estimated weight of substances per year, 1990 to 2016.

 

Figure B5bi. Combined input of hazardous substances to the UK marine environment, as an index of estimated weight of substances per year, 1990 to 2016.

 

Source: Defra Marine Strategy and Evidence Division, using data provided by: Environment Agency, Northern Ireland Environment Agency, Scottish Environmental Protection Agency.

Levels of all six substances declined over the period 1990 to 2016: mercury and lindane each by 90%; cadmium by 87%; lead by 66%; zinc by 63% and copper by 57%.

In the short term, inputs of hazardous substances decreased by 20% from 2011 to 2016 (using a 3 year average for 2011).  Inputs of five of these hazardous substances declined in the short term: lindane had the highest percentage decrease (-56%), followed by lead which decreased by 40%, and then zinc (-7%), and both cadium and mercury decreased by -1%. The input of copper has increased by 1% since 2011.

Inputs into the marine environment are estimated from concentrations and flow rates in rivers entering the sea and those from estuarine and coastal point sources.  Riverine inputs reflect both point and diffuse sources upstream of the sampling point and tend to be strongly influenced by flow rates.  Flow rates are heavily affected by rainfall patterns so year to year fluctuations in pollutant loads are likely.

 

Assessment of change in input of hazardous substances
 

Long term

Short term

Latest year

Combined input of hazardous substances

2010 indicator improving
1990–2016

2010 indicator improving
2011–2016

Decreased (2016)

 

Inputs into the marine environment are estimated from concentrations and flow rates in rivers entering the sea and those from estuarine and coastal point sources.  Riverine inputs reflect both point and diffuse sources upstream of the sampling point and tend to be strongly influenced by flow rates.  Flow rates are heavily affected by rainfall patterns so year to year fluctuations in pollutant loads are likely.

A detailed illustration of changing levels of each input is seen in Figure B5bii.  The low point in 2003 is thought to be a consequence of reduced river flows during an exceptionally dry year.  Conversely, levels of all six pollutants increased in 2012 and again in 2014 corresponding with years of heavy rainfall.  In 2012, England had the wettest year since records began in 1910; the summer was the wettest since 1912 increased rainfall in November and December contributed to extensive flooding.  In 2014, the winter (Jan – Feb) was the wettest since records began.

 

Download Fiche

Download: Datasheet 

 

Last updated: July 2018

Latest data available: 2016