Introduction to Freshwater Algae - Freshwater Algae: Identification, Enumeration and Use as Bioindicators - page 17

Table 1.6 Ecological Diversity of Freshwater Blue-Green Algae.

Major Ecosystem Specific Conditions Benthic Algae Planktonic Algae

Standing waters -
lakes and ponds

Meso- to eutrophic Gloeotrichia : Attached to

substrates. Detached
colonies planktonic

Colonial blue-greens:
Microcystis, Anabaena

Oligotrophic Unicellular blue-greens:

Synechococcus

Hard and soft waters Aphanothece

Soft, acid lakes Cylindrospermum :often

forming dark patches on
submerged vegetation

Tolypothrix : Planktonic
or in submerged
vegetation

Wetlands Soft waters - common in

bogs

Chroococcus - Attached to substrates, mixed with
tangles of filamentous algae or free-floating
Merismopedia - typical of bog-water communities

Open water in bogs Aphanocapsa

Running waters -
streams and rivers

Low N concentrations, high
N:P ratio

Benthic mats: Nostoc,
Calothrix
(Stancheva et al ., 2013)

Oscillatoria rubescens

Extreme environments
Polar lakes, ponds,
soils

Low temperature, low light
(ice cover)

Benthic mats: Calothrix,
Phormidium.
Leptolyngbya
(Martineau et al ., 2013)

Thermal springs 45 ◦ C or greater Mastigocladus laminosus

Oscillatoria
(pigmented)
(Darley, 1982)

Synechococcus lividus
(Stal., 1995)

Brackish waters -
saline lakes

Range of salinity Aphanothece halophytica

(Yopp et al ., 1978).

Spent nuclear fuel
storage ponds

High radioactivity, with
range of radionuclides
including 137 Cs and 60 Co.

Biofilm dominated by
Leptolyngbya
(Evans, 2013).

ecological status (Table 1.6). The dominant pres-
ence of colonial blue-greens in lake phytoplankton
(Fig 1.5.) provides a useful indicator of high nutrient
status and these algae are a key component of various
trophic indices (see Section 3.2.3). Conversely, pop-
ulations of planktonic unicellular blue-green algae
are indicative of oligotrophic to mesotrophic con-
ditions. In streams, the relative abundance of benthic
N 2 -ixing (heterocystous) blue-greens can be used for
rapid nutrient (N concentration) biomonitoring (see
Section 3.4.7).
Changes in the population of colonial blue-greens
in lakes and estuaries may also act as an indicator

of climate change. An increase in the intensity of
Microcystis blooms in San Francisco Bay (USA), for
example, has been predicted with expected increases
in water temperature and low stream low during
increasing incidence of droughts (Lehman et al .,
2013).

1.4 Green algae

In the freshwater environment, green algae (Chloro-
phyta) range in size from microscopic unicellular