coastal eutrophication and the productivity of clams and
TRANSCRIPT
Coastal Eutrophication and the
Productivity of Clams and Oysters
Edward J. Phlips, Shirley Baker, Debra Murie, Erin Bledsoe and Tom Frazer
Department of Fisheries and Aquatic Sciences
Institute of Food and Agriculture Sciences University of Florida
Eutrophic – “Well fed” (Greek)
Oligotrophic – “Little food” (Greek)
Process of eutrophication:
‘multifaceted term generally associated with
increased productivity, structural
simplification of biotic components’ (Wetzel
1983)
Suwannee River Plume – Broad regional impact
Major Questions
Are changes in nutrient load from the
Suwannee River related to the abundance
and composition of plankton in the
surrounding coastal waters?
Is the productivity of clams and oysters
correlated to the abundance and
composition of plankton?
Significance
Defining regions and periods of
maximum production potential
Determining carrying capacity of
production areas
Evaluating risks to productivity
from harmful algal blooms
Clams
Algae
Pro
du
cti
on
Nutrient Availability
Anoxia/hypoxia
Toxic algae
Poor food quality
Food Availability
Food quality
Karenia breve – Gymnodinium breve
10 microns
Neurotoxic Shellfish Poison – NSP - brevetoxin
Karenia breve – Gymnodinium breve
Bacteriastrum
Centric Diatoms
Thalassiosira lacustris Cyclotella striata
Major Questions
*Are changes in nutrient load from the
Suwannee River related to the abundance
and composition plankton in the
surrounding coastal waters?
Is the productivity of clams and oysters
correlated to the abundance and
composition of plankton?
Mean Phytoplankton Biomass
Estimated by Chlorophyll a
1996-1997 1999-2001
Chlorophyll a
(µg chl a / L)
2 40
Effects of Nutrient Loading on the
Phytoplankton Community
Reef Nearshore TN TP
chl chl Load Load Flow Level
Date mg / m3
mg / m3
g N / sec g P / sec
1998-1999 17.8 9.8 323 34.6 Medium-High
(12) (4) (153) (28)
1999-2000 10.9 3.4 112 9.9 Low
(9) (2) (21) (4)
2000-2001 9.8 3.8 130 11.9 Low
(7) (2) (61) (8)
***
Macroalgal Biomass Distribution
Spring 2000 and 2001
Distribution of Sediment Chlorophyll
Spring 2000 and 2001
µg chl m-2
Major Questions
Are changes in nutrient load from the
Suwannee River related to the abundance
and composition plankton in the
surrounding coastal waters?
*Is the productivity of clams and oysters
correlated to the abundance and
composition of plankton?
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Bio
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Gulf Jackson
Pine Island
Clam Size by RegionFall Out-planting with 1-yr Grow-out
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30
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Sh
ell L
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gth
(m
m)
Gulf Jackson Pelican Derricks
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Sh
ell L
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gth
(m
m)
Pine Island Horseshoe
Suwannee
RiverNorth Lease Sites
South Lease Sites
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Bio
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Gulf Jackson
Pine Island
Feeding studies Feeding studies –– Selection and ratesSelection and rates
Tetraselmis maculata
Large green flagellate
~ 10 µm
Isochrysis galbana
Small brown flagellate
~ 5 µm
Synechococcus
Small blue-green
~ 2 µm
Algae Selection Algae Selection ◼◼ TetraselmisTetraselmis = = IsochrysisIsochrysis
> > SynechococcusSynechococcus
◼◼ Clams more selective at Clams more selective at
2020°°C than at 30C than at 30°°CC
◼◼ More selective at lower More selective at lower
concentrations (10concentrations (1055
cells/cells/mLmL) than at ) than at ““bloombloom””
concentrations (10concentrations (1066
cells/cells/mLmL))
Future Plans
Complete quantitative analyses and
model formulations
Generate peer-reviewed publications
Develop EDIS publications for information
transfer to user groups