Page 14 - Freshwater-Biology-and-Ecology-Handbook

Biological Pressures Morphological Pressures
Invasives Substrate
Biogeography Channel section/sinuosity
PREFACE Bio-manipulation/stocking Connectivity
Disease/predation/prey
Depth/area
Productivity
Shading

Climate Change
Season Ecosystem Global warming
Geography Health North Atlantic Oscillation
El Niño

Chemical Pressures
Hydrological Pressures
Concentration /load Velocity/residence time
Alkalinity/acidity Discharge/intermittence
Bioavailability Flood/drought
Temperature Flow duration curve
Toxicity
Oxygen Drainage/impoundment

Figure 1
Main environmental pressures and their units of measure. Source - Adapted from TAG Guidance. (2)

In the past, when freshwater quality was dominated by the water environment. The WFD came into force in 2000
pollution from untreated or partially treated sewage and and set a timetable for implementation. It provides a long-
industrial effluent, we were able to improve environmental term water planning framework for all river basins across
quality simply by measuring and controlling physico- Europe. The first of three six-year river basin planning cycles
chemical parameters. Now that these sources of gross began in 2010 with the publication of River Basin Plans for
pollution have largely been brought under control, we are all EU rivers, and this was repeated in 2015. The next cycle
left with a wide range of ‘multiple’ pressures that prevent began in 2021 and is timetabled to complete in 2027.
the biota from achieving the quality that maximises its
ecosystem services. It is impossible to measure these The breakthrough provided by the WFD was to focus on
pressures directly on a common scale, but biological biological and ecological protection and improvement.
measurements provide a uniform way to measure their For the first time, in the UK and the rest of Europe,
combined impacts. environmental objectives were defined principally in
biological terms and assessed in biological monitoring
With a changing climate and a growing population, programmes, supported by physico-chemical standards
people are putting ever greater pressure on natural and monitoring.
water systems. We must adapt to climate change. Water
adaptation strategies must be made in a sustainable way,
whilst protecting and improving aquatic ecosystems and The Water Framework Directive
biodiversity. Understanding the impacts of our activities Prevents further deterioration and protects and
on aquatic ecosystems and distinguishing these from the enhances the status of aquatic ecosystems and, with
effects of natural processes is critical. regard to their water needs, terrestrial ecosystems and
wetlands directly depending on the aquatic ecosystems.
Baseline assessments of the state of our environment are
important because they enable us to monitor changes in
quality, and predictive techniques are crucial for identifying The role of biological and ecological approaches to water
the mitigation strategies that will achieve the desired management within the WFD will be developed further in
environmental outcomes. Understanding minimum flow Chapter 1.
requirements, the effects of climate change, the influence
of chemical pollution and physical alterations on the biota This focus on ecological outcomes has required significant
are important. They are the focus of ongoing research and development of monitoring and assessment systems which,
development of our biological and ecological monitoring for the first time, will be used to drive significant investment
techniques. and infrastructure development to meet the new objectives.
This has promoted significant co-operative research and
The European Union (EU) Water Framework Directive is method development across Europe, aligned with the needs
the core regulatory instrument to maintain and improve the of the WFD.
water environment across the EU to maintain and improve

14 | Freshwater Biology and Ecology Handbook
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