Harmful algae
• Harmful algal blooms and their effects
• Harmful algae in the sea (and in fresh water)
• Algal toxins and their effects and symptoms
• Fish-killing algal blooms
• Monitoring of harmful algae
BIO 4400/4320 2009 Bente Edvardsen
Harmful algal blooms
Algal blooms:
Increased phytoplankton biomass due to rapid
growth and accumulation
•
•
One or a few species may become dominating
Most algal blooms are non-harmful and beneficial
Phytoplankton are
primary producers
Algal blooms can colour the water red or
brown, called red and brown tides
The dinoflagellate Dinophysis
spp. and the ciliate Myrionecta
rubrum
Bloom of the dinoflagellate
Karenia mikimotoi
Some blooms are harmful for animals and humans
Noctiluca scintillans
Luminescence (morild)
heterotrophic dinoflagellate
Not all red tides are harmful
Blooms of cyanobacteria in fresh water
Akersvannet, Vestfold
Kolbotnvannet
Harmful algal blooms – 3 types
1. Non-toxic, but high biomass cause harmful effects
2. Produce toxins that accumulate in the foob web.
Harmful for humans on consumption of shellfish
and fish.
3. Usually non-toxic for humans, but toxic for fish
and some other animals
Harmful effects
• Toxic mussels and fish
• Health effects in humans upon consumption or other
exposures
• Drinking water toxic for humans and animals
• Mass mortalities of fish and other aquatic organisms
• High biomass, noxious scum and smell lead to
reduced quality of recreational areas
• Economic losses
Human health effects
•
About 300 persons die every year of algal
poisonings
•
Thousands of people (>50 000) are poisoned
every year and obtain long lasting negative
effects
Economical losses for the aquaculture
industry
The ‘algal catastrophe’,
Skagerrak, May 1988
Skagerrak 28 March 2001
Harmful algae in the sea
In Norway
Potentially toxic in Norway
Algal class
Nodularia spumigena
BLÅGRØNNALGER
(Cyanophyceae)
FUREFLAGELLATER
(Dinophyceae)
SVEPEFLAGELLATER
(Prymnesiophyceae)
Alexandrium tamarense
Alexandrium ostenfeldii
Dinophysis acuminata
Dinophysis acuta
Dinophysis norvegica
Karenia mikimotoi
Protoceratium reticulatum
Azadinium spinosum
Chrysochromulina polylepis
C. leadbeateri
Prymnesium parvum
Alexandrium minutum
Prorocentrum minimum
Prorocentrum lima
Chrysochromulina spp.
Pseudo-nitzschia multiseries
P. seriata
P. calliantha
KISELALGER
(Bacillariophyceae)
NÅLFLAGELLATER
(Raphidophyceae)
Heterosigma akashiwo
Olistodiscus lutheus
KISELFLAGELLATER
(Dictyochophyceae)
Pseudochattonella farcimen
Dictyocha speculum
About 2% (ca 100 of 5000) of the marine microalgae are potentially toxic or harmful
Harmful algae in the sea
Haptophytes (Svepeflagellater )
Photo Karl Tangen
Photo Wenche Eikrem
Prymnesium
Protoceratium
Chrysochromulina
Alexandrium
Dinoflagellates, fureflagellater
Photo Lars Naustvoll
Pseudochattonella
Silicoflagellates (kiselflagellater)
Karenia
Dinophysis
Toxigenic cyanobacteria in Norwegain lakes
Order
Species
Chroococcales
Microcystis aeruginosa
Microcystis botrys
Snowella lacustris
Woronichinia naegeliana
Anabaena lemmermannii
Anabaena flos-aquae
Anabaena circinalis
Anabaena solitaria
Anabaena planctonica
Anabaena crassa
Anabaena tenericaulis
Aphanizomenon flos-aquae
Planktothrix agardhii
Planktothrix rubescens
Phormidium formosum
Trichodesmium lacustre
Nostocales
Oscillatoriales
Toxin
Type of
poisoning
Polypeptides Hepatotoxic
Delayed effect
other
Polypeptides Hepatotoksisk
Alkaloides
Neurotoxic
Unknown
Delayed effect
other
Polypeptider
Alkaloider
Hepatotoksisk
Neurotoxic
Delayed effect
other
Toxic cyanobacteria in Norwegian lakes
Woronichinia
Planktothrix
Microcystis
Algal toxins
Type 2. Toxins that accumulate in mussels, fish, birds
and mammals, and are toxic to humans (or mouse)
Based on symptoms
1.
2.
3.
4.
5.
6.
PSP=Paralytic shellfish poisoning
DSP=Diarrheic shellfish poisoning
ASP=Amnesic shellfish poisoning
NSP=Neurotoxic shellfish poisoning
CFP=Ciguatera fish poisoning
AZP=Azaspiracid poisoning
Based on chemistry
1.
2.
3.
4.
5.
6.
7.
8.
Saxitoxin group (PSP)
Okadaic acid group (DSP)
Pectenotoxin group (DSP)
Domoic acid group (ASP)
Brevetoxin group (NSP)
Yessotoxin group
Azaspiracid group (AZP)
Cyclic imine group
PSP - Paralytic shellfish poisoning
toxins and algae
(more than 20 different
tetrahydropurins)
Alexandrium tamarense
PSP - Paralytic shellfish poisoning
• Acute symptoms: Diarrhoea, nausea, vomiting,
tingling sensation, respiratory and muscular
paralysis (lammelser)
• Incubation time: 5-30 min Duration: Days
• Poisoning: About 2500 reported cases before
1993, 1-14% death rate. Some lighter cases in
Norge, no death.
PSP - Paralytic shellfish poisoning
other algae
dinoflagellates
Pyrodinium bahamense
Gymnodinium catenatum
Cyanobacteria: Anabaena spp.
Occurrence of PSP
Increase in
geographic
distribution and
frequency
Cases since 1972
DSP - Diarrhetic shellfish poisoning
toxins and algae
Dinophysis spp.
D. acuta
D. norvegica
D. acuminata
D. rotundata
Prorocentrum
lima
Okadaic acid (OA, okadasyre), dinophysis toxins (DTX),
and pectenotoxins (PTX) are polyethers.
DSP -Diarrheic shellfish poisoning
• Symptoms: Gastrointestinal symptoms (diarrhoea,
nausea, vomiting, abdominal pain), headache.
Tumour promotion?
• Incubation: 30 min-12h Duration: a few days
• Poisoning: Many thousands of cases in Europe, Asia
and Australia/New Zealand. Similar symptoms to
bacterial infection. No death.
DSP occurence
First time
reported from
Japan in 1976
Responsible algae:
Dinophysis spp.
Prorocentrum spp.
CFP - Ciguatera fish poisoning
Toxins and algae
maitotoxin
polyethers
CFP - Ciguatera fish poisoning
• Related to consumption of tropical and
subtropical marine fish (e.g. barracuda, red
snapper, grouper) from some coral reef areas
• Symptoms: gastrointestinal symptoms,
neurotoxic, reversal of hot and cold sensation
• Poisoning: More than 50 000 persons are
estimated to be poisoned every vear. 0.1-12%
death rate. It may take months or years to
recover.
CFP occurrence
Tropical distribution, especially in the French Polynesia
ASP-Amnesic shellfish poisoning
Toxin and algae
Pseudo-nitzschia spp., diatom
(kiselalge)
Domoic acid (DA,
dominsyre)
ASP - Amnesic shellfish poisoning
• Symptoms: Gastrointestinal symptoms
(diarrhoea, nausea, vomiting, abdominal
cramps), headache. Desorientation. Amnesia
(hukommelsestap). Neurotoxic
• Poisonings: First recorded in Canada in 1987
when 105 persons were poisoned and 3 died.
Death rate 3%. No cases in Norway.
ASP occurrence
Mainly in USA
and Canada.
Also detected in
NZ, Ireland, Spain
and Denmark (a
few times in
Norway)
New toxins in marine dinoflagellats
Spirolides/ cyclic imines in Alexandrium
ostenfeldii
(unknown effects in humans)
Yessotoxins in Protoceratium reticulatum
(unknown effects in humans)
Azaspiracids in Azadinium spinosum
(similar to DSP)
Azaspiracid poisoning (AZP)
• Azadinium spinosum
produces azaspirasids
(AZA) that may cause
illnesses in humans
upon consumption of
shellfish. Symptoms
are similar to DSP.
Azadinium spinosum is a
small dinoflagellate
Tillmann et al. 2009
Cyanotoxins
•
•
•
Hepatotoxins:
-microcystins (cyclic heptapeptide)
-nodularin (cyclic heptapeptide)
-cylindrospermopsin (alkaloid)
Neurotoxins:
-saxitoxin (alkaloid)
-anatoxin-a (alkaloid)
-homoanatoxin (alkaloid)
-anatoxin-a(s) (ester)
Skin irritants:
-Lipopolysaccarids (LPS)
-Lyngbyatoxin-a
Chemical structure to cyanotoxins
polypeptides
alkaloids
ester
alkaloid
Type 3. Ichthyotoxic (= toxic to fish)
Toxic algae that harm or kill fish and
other aquatic organisms, but are not
toxic to humans
Ichthyotoxic blooms in Norway
Karenia mikimotoi
1966, 1974-1991 amost every year
Chrysochromulina polylepis
1988, 1989, 1994, 1995
Chrysochromulina leadbeateri
1991
Prymnesium parvum
yearly 1989-1995
Pseudochattonella farcimen
(=Verrucophora farcimen )
1998, 2000, 2001
Ichthyotoxic haptophytes (svepeflagellater)
Prymnesium
Chrysochromulina
Phaeocystis pouchetii
Chrysochromulina polylepis bloom 1988
Illustrasjon: Einar Dahl
Effects of the Chrysochromulina polylepis
bloom in May-June 1988
Chrysochromulina polylepis bloom in 1988:
effects on zooplankton
Long time-series of Chrysochromulina spp. in
Skagerrak
0.6
0.4
0.0
0.2
Cells*106 l-1
0.8
1.0
Chrysochromulina spp.
1990
1992
1994
1996
Year
PO 4
0.6
1998
NO 3
10
2002
NO 2
0.6
5
0.2
0.0
0
2.0
2000
NH 4
SiO 4
4
0.5
Tot N
25
8
15
0
Tot P
Part.P
1.0
0.25
0.4
0.05
(NO 2 +NO 3 ):PO 4
80
40
0
NO 3 :PO 4
80
60
Chla:NO 3
40
20
20
10
0
0
1992 1994 1996 1998 2000 2002
NO 3 :SiO 4
2
20
0
6
4
40
40
Lekve et al. 2006
Tot N : T ot P
0
Chla:SiO 4
150
Chla:PO 4
50
0
1992 1994 1996 1998 2000 2002
year
1992 1994 1996 1998 2000 2002
Distribution of Prymnesium parvum
Œ
Œ
observed
bloom
Prymnesium blooms
z Habitat:
– low salinity (0,8 - 12 PSU)
– Limited area (pond, lake, fjord,
lagune, river)
– nutrient rich
z Moderate to high water temperature
z Fish kills usually only at high algal
concentrations (>100.106 cells L-1)
Prymnesium toxins - structure
A. hemolysin (Kozakai et al. 1982)
B
B. prymnesin-2 and N-acetylprymnesin-2
(Igarashi et al. 1996)
Prymnesium in Ryfylke, 1989
After 1995…
• Fishfarms disappeared from the area
• Prymnesium was rarely observed and
when, at very low concentrations
• New fishfarms (Erfjord Stamfisk) were
established in 2005 in Hylsfjorden
(cradle of the booms)
• 2007 a toxic bloom of Prymnesium
parvum killed 135 tons of caged fish
From Eikrem et al. 2009
From Eikrem et al. 2009
A submergible fish net was mounted over the fish
enclosures during the toxic outbreak preventing the fish
from entering the toxic brackish layer. The fish lost weight,
but no mortalities was observed.
Bloom of Pseudochattonella farcimen
in March 2001
mu
10 µm
satellite image
showing chlorophyll
a concentrations
From: Nansen Senter / CCMS-PML / NASA seaWiFS project
Are harmful blooms increasing in frequency?
Possible explanations
1. Increased awareness and knowledge
2. Increased aquaculture activities and use of
marine resources
3. Increased anthropogenic exposure
4. Increased transportation and dispersal
Some useful links to HAB web pages
• http://www.whoi.edu/redtide/index.html
• http://www.issha.org/
• http://ioc.unesco.org/hab/news.htm
• http://algeinfo.imr.no/
Algal monitoring
• Started in 1989
• 56 stations
• Weekly cell counts of
harmful species
• Reports on the web
(algeinfo)
• Run by IMR, NIVA,
SINTEFF, FD
Summary
•
Most algal blooms are non-toxic. Phytoplankton are important as
primary producers in the food web
•
In the sea ca 2% of the microalgae may be harmful, most are
flagellates. In freshwater mainly cyanobacteria are toxic
•
Some toxins accumulate in clams and other animals. Others kill
aquatic organisms directly.
•
Harmful algae cause health, environmental and economical
problems.
•
Reported HABs have increased in distribution, frequency and
intensity
•
Increased problems are probably caused by increased
awareness and antropogentic activity