putting the puzzle together: connecting the hypersas with brevebuster absorbance spectra,...

Putting the puzzle together: Connecting the HyperSAS with BreveBuster absorbance spectra, fluorometer, extracted chlorophyll and MODIS data. Blake A. Schaeffer, D.

Kamykowski, J. M. Morrison, S. Banks, A. McCulloch, and W. V. Sweet

Introduction

• The Galapagos harbors such great diversity because of its positioning in a complex transition zone between tropical, subtropical and upwelled waters.

• Only place in the world where hammerhead sharks, penguins, and sealions co-exist on the same sub-tidal reef.

Introduction

• Three major current systems influence the Galapagos.

• Cool southern currents from the Humboldt (Peru) system influencing the southern islands.

• Warmer Panama currents that influence the northern islands.

• Strong, large-scale Equatorial Undercurrent (EUC) upwelling in the western archipelago.

Focus

• The EUC is the major oceanographic feature affecting production in the Galápagos, and is strongly associated with local biogeography of marine species.

• Galápagos biogeography/marine ecosystem heterogeneity is a function of oceanographic patterning over small spatial, seasonal and inter-annual scales.

Goals

• Hyperspectral information combined with BreveBuster absorbance spectra, fluorometer, extracted chlorophyll and MODIS data will identify variability of phytoplankton biomass throughout the Galapagos.

• Hyperspectral information will elucidate phytoplankton taxonomy of the Galapagos with the support of HPLC pigment analysis, particulate absorption spectra and BreveBuster data.

Methods

• Sierra Negra• 70 hydrographic

stations• 12 days

Methods

• Phytoplankton – 20 m net– 20 meters depth

• Filtration– Surface only– Extracted chlorophyll a– Particulate absorption

spectra

• Seapoint FL– Top 2 meters bin average

Seapoint Fluorometer

Phytoplankton tows

Filtration

HyperSAS

Methods• MODIS

– Chlorophyll a– SeaDAS v 4.9

• BreveBuster– In situ spectrometer– Phytoplankton class

spectral libraries– Day and night travel

• HyperSAS– 166-channel MiniSpec

radiance and irradiance sensors

– Day travel only

BreveBuster – Mote Marine Aquarium

March 2005Chlorophyll a

(g/L)

084 089

Wet season

Panama current

dominates.

November 2005Chlorophyll a

(g/L)

324 347

Transitionfrom garua

(dry) to wet

season.

Panama current replaces

Peru current.

Transition from wet to garua

(dry).

June 2006Chlorophyll a

(g/L)

190181

MODIS chlorophyll a shows similar trends and range to Seapoint FL chlorophyll a.

MODIS chlorophyll a show similartrends to extracted chlorophyll a, but less agreement in range.

HyperSAS identifies variability not present in MODIS chlorophyll a.

Remote sensing reflectance

Chlo

rophyll

a

Phyco

cyanin

Chlo

rophyll

a

Caro

tenoid

s

Particulate absorption

Particulate absorption spectra

BreveBuster Phytoplankton Class ID

BreveBuster Phytoplankton Class ID

Phytoplankton Tows

Future work• HPLC pigment analysis

– Chemtax

• Particulate absorption spectral library

• Remote sensing reflectance 4th derivative analysis

• HyperSAS phytoplankton class spectral library

• Poster: 4.28-P Today 12:00 – Seasonality of

phytoplankton distributions in the Galapagos Marine Reserve

Chlo

rophyll a

?

Caro

tenoid

s?

Chlo

rophyll a

?

Thank you!

Questions?