Monitoring the Responses of Freshwater Ecosystems to Climate Change - Climate Change Impacts on Freshwater Ecosystems - page 89

Salinity Warmer winters cause

extreme rainstorms and heavy
sea-salt deposition, which
might affect water chemistry.

Acidifying
substances

These parameters are
easy to record and often
incorporated into routine
water chemistry
monitoring.

x x

Total Organic Carbon
(TOC) runoff patterns

Warmer winters produce
higher levels of runoff TOC
release with subsequently
increasing TOC water
concentrations.

TOC levels and/or
absorbance (water
colour)

Water TOC concentrations
reflect changes in runoff
and input of
allochthonous material.

x

Water temperature
effects on
phytoplankton

Increasing water
temperatures lead to shifts
from a dominance of diatoms
and cryptophytes to
cyanobacteria. This effect is
especially pronounced at
temperatures > 20°C, since
cyanobacteria (especially
large, filamentous) and green
algae are favoured at higher
temperatures.

Phytoplankton
biomass and
composition,
cyanobacterial
algal blooms

The shift in community
composition gives
information about the
response of biota to
changed lake
characteristics as water
temperatures.
Phytoplankton
community composition
is routinely monitored for
the Water Framework
Directive.

x x (x)

Primary
production

Water temperature
effects on
macrophytes

Inter-annual variation in water
temperature results in deeper
macrophyte colonization,
greater wet weight biomass,
and an increase in whole lake
biomass.

Water temperature The parameter is easy to

record and often
incorporated into routine
monitoring programmes.

x