Geoscience Reference
In-Depth Information
CHAPTER 21
The Unnatural History of the River
Trent: 50 Years of Ecological Recovery
Terry Langford
1
, Tom Worthington
1
, Peter Shaw
1
,PaulKemp
1
, Chris Woolgar
2
,
Alastair Ferguson
3
, Philip Harding
4
and David Ottewell
5
1
Faculty of Engineering and the Environment, University of Southampton, UK
2
Faculty of Humanities, University of Southampton, UK
3
The Old Dairy, Saul, UK
4
Environment Agency, West Bridgford, UK
5
Environment Agency, Lichfield, UK
Introduction
Improvement in water quality and the recovery
of river ecology from pollution and physical
deterioration require an understanding of the
impacts, remedial interventions and biological
responses involved. Only then can the long-term
recovery of rivers be achieved, by applying the most
appropriate and economically effective measures.
There are four key human contributions that
achieve change: legislation; technology; economics;
and public opinion. To understand the relative
importance of these factors it is necessary to
take a long-term perspective. Human impacts on
rivers have changed over time, driven by shifts
in economic activities (e.g. from agriculture to
industry in the UK in the 19th century; industrial
re-location overseas which began during the
1960s-1970s) and the nature of discharges to river
systems (Sheail, 1997). The relatively clean rivers
of pre-industrial revolution Britain in the 18th
century became polluted by industrial and domestic
waste, compounded by urban and agricultural
runoff (Klein, 1957; Hynes, 1960; Lester, 1975;
Wheeler, 1979; Wood, 1982; Holland and Harding,
1984; Whitton and Crisp 1984; Sheail, 1993;
Burton, 2003; Langford
et al.
, 2009, 2010). The
change was exacerbated by population migration
from rural
The recovery and rehabilitation of rivers from
severe pollution, and also from geomorphological
and ecological degradation, is of paramount
importance for river conservation and
management. Many rivers in developed countries
have shown dramatic chemical and ecological
improvement since the 1970s (Lester, 1975;
Cioc, 2002; Langford
et al.
, 2009; Langford
et al.
,
2010), but river pollution and impoundment
have continued to increase in many developing
countries over the past four decades (Revenga
et al
., 2000; V or osmarty
et al.
, 2010). Pollution is
still a major threat to freshwater biodiversity in
developing countries (Dudgeon
et al.,
2006) and
could lead to local extinctions of species in a similar
fashion to that witnessed in developed countries
as a result of industrial and population growth
from the 18th century (Sheail, 1998; Harrison
and Stiassny, 1999; Worthington, 2010). Already,
population growth and rapid industrial expansion
in developing countries have accelerated the
physical, chemical and biological deterioration of
many rivers, despite an increasing demand for
good quality potable water (Duda and El-Ashry,
2000).
to urban areas, so by the early 1850s
