Phytoplankton Blooms, Red
Tides and Toxic Algae:
Similar . . . . But Different!
G. Jason Smith, Ph.D.
Moss Landing Marine Laboratories
Lab and Field Explorations in Marine Science
Teacher Enhancement Program
Moss Landing Marine Laboratories
© G. Jason Smith, Ph.D.
Some Background Information
“What the heck are ‘phytoplankton’?”
- Microscopic, single-celled “plants”
- The base of the food web in the upper ocean
Fisheries are dependent upon their growth
- The term ‘phytoplankton’ encompasses a very
diverse collection of micro-organisms
A drop of seawater might contain:
Phytoplankton 101
What do phytoplankton need to grow?
- Most are “autotrophic”
Can make required complex biochemicals from simple
inorganic molecules. Energy and carbon backbones for
these biochemical syntheses derive from Photosynthesis
- Their “food” requirements include:
a dissolved source of nitrogen, phosphorous, silicate,
carbon dioxide, metals and....... LIGHT
“Mixotrophs” can used dissolved organic compounds and
bacteria or other algae!
Phytoplankton 101
How do phytoplankton grow?
Asexual reproduction permits rapid expansion of their populations
in “good” environmental conditions
Idealized Growth Curve
c
en
Biomass or Numbers
Stationary
sc
ne
L
Exp og /
one
ntial
e
Growth in Numbers:
Cell Division,
Clonal Growth
Se
Growth of Biomass:
Primary Production,
Photosynthesis
Lag
Time From Nutrient Pulse, days
© G. Jason Smith, Ph.D.
What are potential sources of nutrients in Monterey Bay?
Upwelling Along the Pacific Coast
Provides Nutrients For Phytoplankton Growth
© G. Jason Smith, Ph.D.
http://www.pfeg.noaa.gov/products/PFEL/modeled/indices/upwelling/upwelling.html
Relaxation
Upwelling
Upwelling Index, Offshore Transport
M3 / s / 100 m coastline
Upwelling Is Seasonal Along The Central Coast
2003
2004
http://www.pfeg.noaa.gov/products/PFEL/modeled/indices/upwelling/upwelling.html
Fate of Upwelled Water
Surface current radar indicates that a large proportion of
the upwelled water mass is entrained in Monterey Bay
http://www.oc.nps.navy.mil/%7Eicon/frames/hfradar_frame.html
Phytoplankton 101
What is a ‘phytoplankton bloom’?
-
Occur when environmental conditions promote the
growth of phytoplankton in excess of loss due to death
and zooplankton grazing or advection from the system
PRODUCTION >> LOSS
- Conditions are species-specific, blooms can occur with
many species or be dominated by single species
Ocean water goes…
From this
© G. Jason Smith, Ph.D.
To this!
© G. Jason Smith, Ph.D.
Fate of ‘Blooming’ Particles In Water
Phytoplankton are effectively biochemical factories and as
such represent rich food sources for secondary consumers
Food Chain
Food Web
Keep in mind that
a large fraction of
diatom blooms can
sink to the bottom
and provide food to
benthic feeding
organisms
http://www.bigelow.org/edhab/
Algal biochemicals, good and bad, will follow these same
pathways to higher consumers supporting their growth or
causing detrimental effects
Types of Blooms
What is a ‘ Red Tide ’ ?
- A bloom dominated by one species of phytoplankton
- Classically, a bloom and subsequent aggregation of
dinoflagellates
Types of Blooms -2Questions about ‘ Red Tides ‘ ?
- Are all blooms Red Tides?
NO!
- Are all Red Tides blooms?
YES (+/-)
They result from blooms, but formation of dense aggregations
may be aided by prevailing oceanographic conditions
- Are all Red Tides Red?
NO!
In common use, the term is applied to blooms by many different
(unrelated) species and can occur at different spatial scales
Brown Tides
Types of Blooms - 3 Are there other names for ‘red tides’ ?
“Red tide” is a term often misapplied to widespread
nuisance and harmful algal blooms
- Names are often applied relative to perceived impact of bloom
- Nuisance bloom: frequent in estuaries, enclosed bays,
persistent discoloration of water, +/- side effects
- Harmful Algal Blooms (HABs): blooms that cause economic
and/or health impacts on local communities either through
physical changes in water quality or biologically by production
of variety of toxic compounds.
- HABs in Monterey Bay are a research focus of several labs at
MLML, MBARI, UCSC and CSUMB
Red Tide and HAB Species
HAB species represent the gamut of protistan diversity
Multicellular
Eukaryotes:
Macroalgae
HAB Species
common along
the lower branches
of the tree of life
Unicellular
Eukaryotes
Prokaryotes:
Cyanobacteria
http://tolweb.org/tree/phylogeny.html
Red Tide and HAB Species
Not toxic but can cause problems due to oxygen
depletion and physical irritation
Red Tide and HAB Species -2Toxin producing species can be deadly
if one eats something that has eaten them
Local HAB Players And Toxins
As diverse as the phytoplankton that produce them
Most can be readily transferred through the food web
TOXIN
HUMAN SYMPTOMS
Okadaic Acid
DSP
Diarrhetic Shellfish
Poisoning
Dinophysis spp.
PSP
Paralytic Shellfish
Poisoning
Alexandrium catenella
Sagitoxins (multiple forms)
ASP
Amnesic Shellfish
Poisoning
© G. Jason Smith, Ph.D.
Pseudo-nitzschia australis
Domoic Acid
Even more world wide!
Detection of HAB Species
How do we find out what’s in the water?
Molecular probes facilitate detection and enumeration of
HAB species in complex environmental samples
Probes target nucleic acid sequences that are highly conserved in all organisms
Technology pioneered by researchers at MBARI
http://www.whoi.edu/redtide/
Miller and Scholin, 2000
HAB Events Are Globally Distributed
Are they increasing in frequency?
Evidence indicates this, but are we just being more observant?
Impacts of HABs
Large economic impacts on fisheries, tourism, water
quality and associated health care costs has lead to
increased and targeted funding for HAB research
Yet monitoring is still funded only at low levels…. Need help!
Woods Hole Oceanogr. Inst. Tech. Rept., WHOI-2000-11
Summary of HAB Research Efforts At MLML
© G. Jason Smith, Ph.D.
Continued development and refinement of HAB monitoring
technologies
- identification of HAB species and toxin production
Determination of environmental conditions promoting HAB
development and vectors for toxin transfer through the
food web
Define biosynthetic pathways for HAB toxins
- provide means to develop therapuetic strategies
Determine function of HAB toxins in the species of origin
- what are they used for?
Assessment of HAB mitigation strategies
Web Resources For HABs and Phytoplankton
Lots of additional links at each site
National Office for Marine Biotoxin and Harmful Algal Bloom Research:
http://www.whoi.edu/redtide/
IOC Harmful Algal Bloom Programme:
http://www.ioc.unesco.org/hab/
California Department of Health Services:
http://www.dhs.cahwnet.gov/ps/ddwem/environmental/Shellfish/Shellfish.htm
Northwest Fisheries Science Center Harmful Algal Bloom Program:
http://www.nwfsc.noaa.gov/hab/
NOAA Center for Coastal Environmental Health and Biomolecular Research:
http://www.chbr.noaa.gov/CoastalResearch.html
Marine & Freshwater Biomedical Sciences Center:
http://www.rsmas.miami.edu/groups/niehs/science/toxins.jsp
Toxic and Harmful Algal Blooms – Education Activities:
http://www.bigelow.org/edhab/
THANKS FOR LISTENING!