Harmful Algal Blooms in Ponds

53 Pages·2015·3.31 MB·English

Harmful Algal Blooms in Ponds:
Causes, Concerns, and
Management
Eugene Braig, OSU Extension, School
Program Director, of Environment and
Aquatic Ecosystems Natural Resources
OHIO STATE UNIVERSITY EXTENSION
Harmful Algal Blooms in Ponds
• What is this stuff!?
• What causes it?
• Concerns
• Management strategies
OHIO STATE UNIVERSITY EXTENSION
What is this stuff!?
• Cyanobacteria are ordinarily responsible for
harmful algal blooms (HABs).
• Not true algae: Cyanobacteria are often called
“blue-green” algae.
• They are now recognized as bacteria that
contain chlorophyll and are capable of
photosynthesis.
• Cells of most species grow together in
colonies.
• Most are capable of fixing their own nitrogen
from the atmosphere using specialized cells
called heterocytes.
• Without the need for N compounds as nutrients, P
enrichment can favor cyanobacteria blooms.
• A bloom is simply an abundant or excessive
growth of algae or cyanobacteria.
OHIO STATE UNIVERSITY EXTENSION
What is this stuff!?
OHIO STATE UNIVERSITY EXTENSION
The major HAB players
• Microcystis P
h
o
ot
• Colonies of small, spherical, c
r
e
bright green globs that vary d
M :ti
buoyancy to seek optimal light
e
!
conditions.
• Can turn the water column green
or form large green slicks on the
surface.
• Patches of turquoise and white
foaminess often appear.
CP
rh
• Cannot fix nitrogen. ao
• By far the most common to Ohio drofw oterc
pwoantedrss a(nthde w “Mesikteer”n o Lf a“Aken nEieri,e PE oihO , :ti dmiJ
A
Fannie, and Mike”).
OHIO STATE UNIVERSITY EXTENSION
The major HAB players

• Planktothrix
(some species used to
be known as Oscillatoria)
• Colonies of planktonic filaments
that distribute through the water.
• Often appears as classic dark-
colored “blue-green” water but
some species have a reddish-
brown hue.
• Can be associated with an oily-
looking surface film.
• Cannot fix nitrogen.
Photo credit: Linda Merchant-Masonbrink, Ohio EPA
• Recently very common to Ohio’s
reservoirs and inland waters.
OHIO STATE UNIVERSITY EXTENSION
The major HAB players
• Aphanizomenon
• Colonies of planktonic filaments that
often bundle together and look like
tiny grass clippings.
• Fixes atmospheric nitrogen in
heterocytes.
• Sometimes sold as a dietary
supplement. However, the
supplement is not regulated and
may contain cyanobacterial toxins.
Consumers beware!
Photo credit: US Fish & Wildlife
• The third of the three historically Service, Klamath Falls, OR
dominant species in Lake Erie (the -
phani- of “Annie, Fannie, and
Mike”).
OHIO STATE UNIVERSITY EXTENSION
The major HAB players

• Oscillatoria
(and related benthic
species)
• Colonies of rather globby-looking
filaments growing on pond
substrates.
• Often form mats along the bottom
that float to the surface later in the
growing season.
• Lacks specialized cells but still fixes
nitrogen from the atmosphere.
Photo credit: Frank Gibbs
• Very common to shallow waters of
ponds and relatively tolerant of low-
light conditions.
OHIO STATE UNIVERSITY EXTENSION
The major HAB players BP
rh
dio
megc ot
r
ae
nd
U ,sti
revin :T .rD
• Lyngbya o ytismoh
(the outdated name Plectonema T fsa
o
el
is still sometimes used) d
o

• Colonies of clustered filaments,
usually visible to the naked eye.
• Often form dense mats along the
bottom that float to the surface later
in the growing season.
• Lacks specialized cells but still fixes
nitrogen from the atmosphere.
• One of Ohio’s recently problematic
species (specifically Lyngbya wollei),
especially on Maumee Bay near
Toledo.
OHIO STATE UNIVERSITY EXTENSION
The major HAB players
• Cylindrospermopsis
• Colonies of planktonic filaments
that distribute through the water
column.
• Fixes nitrogen and can be
distinguished from Planktothrix by
teardrop-shaped heterocytes.
Photo credit: David Patterson and Bob
• A recent invader to Ohio’s Lake
Andersen, Provasoli-Guillard Center
Erie waters and Buckeye Lake.