Eric Milbrandt PhD Marine Laboratory SanibelCaptiva Conservation Foundation SCCF Caloosahatchee Science Workshop 2013 Florida Gulf Coast University 112013 Background Unattached macroalgae is a ID: 414898
Download Presentation The PPT/PDF document "Macroalgae as an Indicator of Estuarine ..." is the property of its rightful owner. Permission is granted to download and print the materials on this web site for personal, non-commercial use only, and to display it on your personal computer provided you do not modify the materials and that you retain all copyright notices contained in the materials. By downloading content from our website, you accept the terms of this agreement.
Slide1
Macroalgae as an Indicator of Estuarine Condition
Eric Milbrandt, Ph.D. Marine LaboratorySanibel-Captiva Conservation Foundation (SCCF)Caloosahatchee Science Workshop 2013Florida Gulf Coast University11/20/13Slide2
Background
“Unattached” macroalgae is a common component of seagrass communitiesProvides food and refuge for seagrass fauna (Virnstein and Carbonara 1985, Fry 1984)Has high levels of productivity (Williams 1977)Contributes to the DOC pool through decomposition (Zieman 1984)High levels of nutrition, little refractory carbon (Hermann 1994)Extensive drift algal abundances decrease the amount of available light in seagrass (William Cowper 1978, Montfrans 1984) Drift algal blooms decrease seagrass vertical shoot density in the presence of urchins (Macia 1999)
4/27/10, trawls in San Carlos Bay
12/6/10, near causewaySlide3
Occurrences of “Drift Algae”
Large accumulations after storms (Williams Cowper 1978) in Biscayne Bay (Josselyn 1977)
“Tumbling” in sparse seagrass in the IRL (
Virnstein
1985), up to 0.5 km/day (
Holmquest
1994)
10/19/13 Knapp’s Point after TS Karen
Initially attached to substrata such as seagrass shells rocks or
sponges and breaks
loose
Usually
non-calcified fleshy or filamentous, reproduce
vegetatively
(Norton & Matheison 1983)
12/15/12 Sanibel LighthouseSlide4
Previous studies in FL
LocationNo. of SpeciesGroups
Dominant
Species
Mean Biomass
Ft.
Pierce (Benz et al. 1979)
63
3 blue-green
12 green
9 brown
39 red
Acanthophora
spicifera
Chondria
tenuissima
Dictyota
dichotoma
Hypnea
spp
.
Spyridia
filamentosa
Giffordia
mitchelliae
Gracilaria
spp
.
Rosenvingea
intricate
1.8-8.7 g dry
wt
m
-2
Anclote estuary (Hamm
and
Humm
1976)
65
5 blue-green
15 green
13 brown
32
red
Laurencia
obtusa
L.Poteaui
Digenia
simplex
Sargassum
spp.
240 g dry
wt
m
-2
Mid-Indian River Lagoon (
Virnstein
and
Carbonara
1985)
-
-
Gracilaria
spp.
Spyridia
filamentosa
Jania
adhaerens
Rosenvingea
intricata
Acanthophora
spicifera
Laurencia
spp.
Cladophora
prolifera
Hypnea
spp.
Dictyota
dichtoma
0.03-164
g dry
wt
m
-2
San Carlos Bay
/Gulf of Mexico (Milbrandt 2010)
96
1 blue-green
12
green
20 brown
63 red
This presentation
0.01-224 g dry
wt
m
-2Slide5
Drivers
Eutrophication-Algal biomass linked to N-loadingWaquoit Bay Massachusetts, Gracilaria tikvahae (Valiela 1992)Bermuda, Caulerpa prolifera (Lapointe 1989)French Mediterranian coast, Ulva lactuca (Maze et al 1993)Sanibel Island, Hypnea, Soleria Dawes (2003)Slide6
Caloosahatchee versus other estuaries
200800Biomass g DW m-2
Dixon 2008 TN = 1,873 MT (1,873 X 10
3
kg) yr-1 Caloosahatchee
Biomass 100-200 g m
-2
not uncommon
What is the tipping point?
Valiela
(1997)Slide7Slide8
Fragmentation
Hypnea fragment survival data support the proliferation that was observed in late 2006, early 2007Sanibel;02/21/07(Vermeij et al. 2009)Slide9
Significant differences in species composition and abundance at inshore vs. offshore locations
Common SpeciesSlide10
INSHORE
OFFSHORESlide11
INSHORE
OFFSHORE
2008-2010. Each point represents the mean biomass (n=20) Inshore CES11, near
Fishermans
Key; offshore is GOM12, 5 miles west of Redfish pass.Slide12
Aldridge and Trimmer (2005) Half saturation constants for green macroalgae (NO
3) 0.3 mg/L N. In: Anderson and Conley (2005)Ambrose EPA WASP models use 0.1 mg/L N half saturation for macroalgal external N uptake.Sufficient nutrients in the lower Caloosahatchee Estuary to support year round macroalagal growth. Slide13
Driver-Irradiance
Higher irradiances inshore from Dec. to May after N-loading.Offshore, high irradiances coincident with flows and loading
(SCCF, Ladyfinger
Lakes 4/1/13)Slide14
Driver-herbivory
Lack of inshore urchins?Slide15
Top Down Control
Evidence from panhandle that grazer abundance can control macroalgal proliferations (Heck and Valentine)Results from one offshore location with abundant grazers suggests some top down control at GOM04 (Coen et al. 2010) but low salinities prevent larval settlement in San Carlos Bay Slide16
Driver-Roughness
Benthic habitat maps(G. Foster 2010)Slide17
Driver-Temperature
Temperature had a significant affect on photosynthesis and daily growth, salinity did not (Brown, USF M.S. thesis 2001)Temperatures can be several degrees warmer in shallow sites (SCCF RECON data), growth rates from the field are needed. Slide18
Biomass and percent cover (
Scanlan 2009 framework), N-loading, residence time vs. growth ratesInshore and offshore locations needed to capture large (extreme)
interannual
differences in S79 flows
Improve CHNEP mapping by determining accuracy of SAV maps (patchy/continuous, with/without macroalgae)
Improves SAV indicators by providing additional drivers (space competition) and ecosystem services
Improves beach condition indicators (red tide, bacteria)
Methods and equipment proven and tested in the 2010 study
Indicator ConsiderationsSlide19
SCCF Current efforts
Growth and N uptake rates (ammonia, NOX, TN) of local speciesMeasure growth rates (or mortality rates) of beach collected drift algaeQuantify biomass and percent cover from a 4 shore-side locationsDevelop a key to common species in SW Florida Workshop with FDEP and others to teach the use of the keys to identify to macroalgae to Genus and improve transect monitoringSlide20
Growth Rates – field incubations
DateSpeciesVolumeWet Weight
Date
Volume
Wet Weight
10-23-13
Halymenia floresia
19 mL
14.91 g
11/6/13
17.6 mL
20.81 g
10-23-13
Agardhiela
subulata
16.8 mL
14.19 g
11/6/13
26 mL
23.24 g
10-24-13
Agardhiela subulata
40 mL
37.46 g
11/6/13
62 mL
62.73 g
10-24-13
Codium taylorii
102 mL
102.14 g
11/6/13
131 mL
135.35 g
10-24-13
Solieria
filiformis
1.8 mL
1.13 g
11/6/13
2 mL
1.29 g
10-24-13
Gracilaria tikvahiae
12 mL
12.79 g
11/6/13
12.1 mL
11.95 g
10-24-13
Botrycladia occidentalis
46 mL
46.67 g
11/6/13
71 mL
76.63 gSlide21
Acknowledgements
Drs. Loh, Parsons, Everham, A.J. Martignette, Jeff Siwicke, Brad Klement, Keleigh Provost, Mark Thompson, Drs. Greg Foster, Ray GrizzleFunding Partners:James Evans, City of SanibelSteve Boutelle, Lee County, WCINDRob Loflin, City of SanibelMike Campbell, Lee County