IAFE   05512
INSTITUTO DE ASTRONOMIA Y FISICA DEL ESPACIO
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Variability of La Plata River turbid waters using MODIS-Aqua images and its relation to fish habitat selection
Autor/es:
DOGLIOTTI, A.I.; JAUREGUIZAR, A. J.; RUDDICK, K.; GUERRERO, R. A.
Lugar:
Liege
Reunión:
Conferencia; 44th International Liège Colloquium on Ocean Dynamics: ?Remote sensing of colour, temperature and salinity ? new challenges and opportunities?; 2012
Resumen:
La Plata River drains
the second largest basin in South America after the Amazon
River and is considered one of the most turbid rivers in the
world. It carries high amounts of nutrients, suspended particulate and
dissolved organic matter to the adjacent shelf waters which impact the ocean?s
physical, chemical and biological properties. The estuary is an area of high
ecological importance. The outer region, where the freshwater (rich in
nutrients) interacts with the coastal water, is the spawning and nursery area
of many coastal species. The objective of the present study is to analyze the
variability and offshore export of La
Plata turbid waters into the adjacent continental
shelf and its relation to the habitat selection of the whitemouth croaker
Micropogonias furnieri. This fish is one of the most important species in terms
of biomass that supports the traditional fisheries of the Argentinean,
Brasilian and Uruguayan coastal region and its spatial distribution is highly
influenced by salinity and turbidity differentially according to the life
stage. Satellite ocean color data were used to present the synoptic
quantification of turbidity variability on seasonal and interannual timescales
for La Plata
river plume area. Eight years (2002-2010) of MODIS-Aqua local area coverage
were analyzed. Standard ocean colour products are not valid in these extremely
turbid waters. Therefore, turbidity maps were generated using near infrared
(NIR) and short wave infrared (SWIR) bands with a modified atmospheric
correction algorithm which takes into account non-zero reflectance in the SWIR
bands. Results show that the spatial distribution pattern of age-classes of
Micropogonias furnieri is highly related to specific turbidity ranges. The role
of forcing such as river discharge and wind-driven circulation in the
redistribution of the sediment plume is also analyzed both at seasonal and
interannual time scales using in situ and scatterometer wind data.