FREE-FLOATING PLANTS

PLATE 1 Azolla - free floating fern up to 1cm wide, 3cm long. Plants red or green.Common in waters with slow movement, high nutrients.

PLATE 2 Azolla species growing with Ludwigia peploides. Mat forming.

PLATE 3 Spirodela - duckweed (small leaves) with some Potamogeton tricarinatius (large leaf). Spirodela can cover large areas of the surface, matlike, plants may have small roots if lifted out of water. Grows in still waters.

GREEN ALGA

BRYOPHYTE

PLATE 4 (right) Chara (muskgrass), often dark grey-green with orange or green pinpoint fruits (left) Nitella often greener in colour, grows in more aid conditions

PLATE 5 Riccia - a liverwort. Open network of branched thallus up to 5cm diameter. Found in areas of slow moving wter, often swamps and creeks.

PLATE 6 Ricciocarpus - found on water surface. Free floating thallus. usually green on top and purple underneath.

FILAMENTOUS GREEN ALGA

PLATE 7 Hydrodictyon - alga forms a green/yellow mass, like a hair net

PLATE 8 Filamentous green alga in channel near Griffith, NSW. Dominated by Hydrodictyon and Cladophora

PLATE 9 Cladophora - filamentous alga, grows in clumps, can form large mats green or brown in colour. Filaments look and feel like coarse hair.

PLATE 10 Enteromorpha - filamentous green alga, green to yellowish-brown. Often indicative of high nitrogen levels.

PLATE 11 Spirogyra - filamentous green alga that feels like soapy hair. Usually bright green, grows in slow flowing or static water.

BLUE-GREEN ALGA

PLATE 13 Anabaena - blue-green alga bloom on Namoi river. Lighter colour due to Euglena presence in the mixed bloom..

PLATE 14 Anabaena circinalis bloom, Darling river . Strong green colour with scum formed. note blue colour due to phycocyanin pigment.

PLATE 15 Anabaena circinalis in Darling river . Growing with water plant, Ludwigia peploides. Strong blue-green colour due to algal cells breaking down and releasing pigments.

PLATE 16 Microcystis species in Chaffey Dam, NSW. the scum is a thick green, paintlike cover.

PLATE 17 Microcystis and Anabaena bloom in Carcoar Dam, NSW.

MICROSCOPIC GREEN ALGAE

EUGLENOIDS (flagellates)

PLATE 18 Chlamydomonas - Scum of this microscopic alga. Green/khaki in colour. These scums look similar to blue-green alga species and identification is by microscopic examination.

PLATE 19 Green Euglena bloom in a farm dam. Scum often has skin like surface with folds. Scums common where there is lots of organic material in the water.

PLATE 20 Red Euglena bloom in creek near Boomi, NSW. Euglena species have the ability to swim freely to the surface and form scums when there is little water movement.

DIATOMS

BLUE-GREEN ALGA (colonies)

GREEN ALGA

PLATE 21 Diatom bloom. Found in both fresh and saline water. These blooms may colour the water brown.

PLATE 22 Microcystis growing in a pond. The algae forms as colonies on the surface of the water. These colonies may form scums as they get bigger and algae numbers increase.

PLATE 23 Pediastrum scum on a farm dam near Windsor, NSW. Algae form a scum that is made up of many small, rectangluar green specks less than 3mm long.

HEALTHY SITUATIONS

PLATE 24 A healthy mix of the aquatic plants Nymphoides (large roundleaf), Ludwigia and the small floating duckweeds. (Toonumbar Reservoir)

PLATE 25 A healthy urban creek. Albury, NSW.

Bloom in Grandview park, Beijing .

Photo 1. Nostoc (Anabaena) azollae

Photo 2. Nostoc (Anabaena) azollae

Photo 3 Cylindrospermopsis rasborski

Photo 4 Microcystis colony

? 2002. NSW Murray Regional Algal Coordinating Committee, MRACC. Unless otherwise specified, maps and images are copyrighted to Department of Land and Water Conservation, NSW.