26 research outputs found
Elements of support to estimate total and new primary production in the Gulf of California based on satellite data
High rates of primary production support the great animal biodiversity of the Gulf of California. One of the main limitations to estimate total (PT) and new (PNEW) primary production by 14C and 15N bottle incubations, respectively, is the small number of point samples generated for a particular area, and with very poor time coverage. Satellite ocean color sensors offer an alternative to estimate phytoplankton production rates in the oceans with an ample spatial-temporal variability that is not possible to cover with research vessels. With ocean color sensors in orbit, scientific expectations remain to improve ocean primary production models. Parameters used by these algorithms fall into three categories: environmental, ecological, and physiological. A review is given on studies that have generated information on these parameters for Gulf of California waters, and opportunities for new research are highlighted. Satellite surface pigment (Chls) and irradiance data (PARsat) need to be associated to vertical profiles (Chlz and PARz) generated with a Gaussian distribution function and Lambert-Beers law, respectively. A detailed description is given of the parameters that characterize this Gaussian function and a vertical attenuation coefficient of PAR variable with z, for different seasons and regions within the Gulf of California. The weakest part of modeling primary production are the photosynthesis-irradiance (P-E) curve parameters: the initial slope, assimilation number, and quantum efficiency, and these give us an opportunity for new research. Summer data to characterize all the set of parameters needed for modeling primary production based on satellite data are the scarcest
Zooplankton in a whale shark (Rhincodon typus) feeding area of Bahía de los Ángeles (Gulf of California)
Bahía de los Ángeles (BLA) is highly influenced by oceanographic processes that occur in Canal de Ballenas, favoring primary and secondary production inside the bay. Zooplankton is an important item in the diet of the whale shark (Rhincodon typus). The whale shark supports BLAs eco-tourism industry. El Rincón (southern BLA) is a preferential feeding area of the whale shark. Zooplankton surface samples were collected at twelve locations in El Rincón in September, November, and December, 2009. Eleven phyla were identified, belonging to both meroplankton and holoplankton. In September the meroplankton fraction was 62.6% of the total abundance, in November it only accounted for 8.6%, and in December it accounted for 14%. This suggests that the breeding season of fish and invertebrates was prior to the September sampling. Copepods, which are the preferred prey for immature whale sharks, always had the largest fraction of the holoplankton. Copepods had relatively low levels of abundance at all sampled locations (<10,000 ind m-3 ) in September and December. Their largest abundance was in November (up to >50,000 ind m-3 ), with an average of 73.8% of totalzooplankton abundance. Whale sharks were sighted feeding in November, at sites with large abundance ofzooplankton, especially Acartia spp. Whale sharks were not sighted when Acartia was absent. Data in the literature and in this work supports the perception that high abundance of Acartia may be the determining factor for the congregation of whale sharks in El Rincón
Spatial and temporal variation of satellite-derived phytoplankton biomass and production in the California Current System off Punta Eugenia, during 1997-2012
The great biodiversity of the California Current System area off Punta Eugenia is supported by high phytoplankton production (PP) caused by coastal upwelling. Satellite imagery was used to characterize the sea surface temperature (SST), phytoplankton biomass (Chlsat), and PP variation in this area during 1997-2012, and to generate a first approximation to its climatology, or an average year. Chlsat and PP had higher values inshore (0-120 km from shore) than offshore. SST had minima inshore and maxima offshore from January through October, with a gradient reversal at the end of autumn. SST often presented spatial distributions with minima and maxima suggesting mesoscale phenomena, such as meanders and eddies. These affected Chlsat and PP inshore. In general, inshore Chlsat and PP were high in March-August (up to >5 mg m-3, and >3.5 g C m-2 d-1), and low in September-February (up to ~1.2 mg m-3, and ~1.2 g C m-2 d-1). Offshore (120-240 km), Chlsat and PP presented similar and relatively low values throughout the whole year, ~0.3 mg m-3 and ~0.5 g C m-2 d-1. Most Chlsat and PP variation was in the annual and interannual periods. Chlsat data from 1998 (El Niño year) and those of 2000 presented significant differences for the inshore region. But, when comparing other El Niño years, there were no significant differences, suggesting that the local impact of ENSO events depend on the type of El Niño, the Pacific decadal oscillation phase, and the incidence of mesoscale phenomena such as meanders and eddies.The great biodiversity of the California Current System area off Punta Eugenia is supported by high phytoplankton production (PP) caused by coastal upwelling. Satellite imagery was used to characterize the sea surface temperature (SST), phytoplankton biomass (Chlsat), and PP variation in this area during 1997-2012, and to generate a first approximation to its climatology, or an average year. Chlsat and PP had higher values inshore (0-120 km from shore) than offshore. SST had minima inshore and maxima offshore from January through October, with a gradient reversal at the end of autumn. SST often presented spatial distributions with minima and maxima suggesting mesoscale phenomena, such as meanders and eddies. These affected Chlsat and PP inshore. In general, inshore Chlsat and PP were high in March-August (up to >5 mg m-3, and >3.5 g C m-2 d-1), and low in September-February (up to ~1.2 mg m-3, and ~1.2 g C m-2 d-1). Offshore (120-240 km), Chlsat and PP presented similar and relatively low values throughout the whole year, ~0.3 mg m-3 and ~0.5 g C m-2 d-1. Most Chlsat and PP variation was in the annual and interannual periods. Chlsat data from 1998 (El Niño year) and those of 2000 presented significant differences for the inshore region. But, when comparing other El Niño years, there were no significant differences, suggesting that the local impact of ENSO events depend on the type of El Niño, the Pacific decadal oscillation phase, and the incidence of mesoscale phenomena such as meanders and eddies
Phytoplankton production by remote sensing in the region off Cabo Corrientes, Mexico
Integrated total phytoplankton production (PPmod) (grams of carbon per square meter per day, gC m-2 d-1) was calculated for the oceanic region off Cabo Corrientes, Mexico. This was done with semi-analytic models from the literature and using chlorophyll a concentrations (Chlsat) and photosynthetically active radiation (PARsat) from monthly composites of the satellite sensor SeaWIFS, for May and November 2002, and June 2003. Average values for PPmod had a seasonal variation for the inshore (1.50 and 0.70 gC m-2 d-1 for May and June, and 0.38 for November) and the offshore (0.55 and 0.41 gC m-2 d-1 for May and June, and 0.31 for November) zones. It is interesting to note that our PPmod data are similar to the previously reported PP14C values for the Cabo Corrientes region. In general, Chlsat and PPmod support the previously reported ship data, which showed intense upwelling conditions during May, an upwelling relaxation period in June, and non-upwelling in November. Estimated PPmod values are within the range of those for other upwelling enriched ecosystems of the Pacific off Mexico
Carbono orgánico nuevo frente a la Península de Baja California: series de tiempo y climatología
Time series of new phytoplankton production (Pnew) off Baja California from 1970 to 2008 computed using statistical models of temperature-nitrate relationship in ten groups of coastal and oceanic stations (Lines 90, 107, 120, 137 and 157) of the CalCOFI-IMECOCAL network, are presented. Pnew was calculated from the -ratio and total primary production (Ptotal). Spatially, the most productive areas of the region were Lines 90, 120 and 157. Pnew of lines 107 and 137 had relatively low values. These two lines marked the border between the northern and southern areas of the studied region. Seasonally, Pnew was high in the spring-summer transition, decreased in summer and autumn, and increased in winter. Pnew was related to coastal upwelling index, and we conclude that for an index of less than 200 m3/s/100 m, Pnew increases and its maximum occurs in phase with the coastal upwelling index. For an upwelling index greater than200 m3/s/100 m Pnew decreases and both series are out of phase.Se presenta la serie de tiempo de la producción fitoplanctónica nueva (Pnueva) frente a la Península de Baja California de 1970 a 2008, calculada por modelos estadísticos de la relación temperatura-nitrato en diez grupos de estaciones costeras y oceánicas de las Líneas 90, 107, 120, 137 y 157 de la red CalCOFI-IMECOCAL. La Pnueva se calculó a partir de la razón- y la producción primaria total (Ptotal). Espacialmente las zonas más productivas fueron las oceánicas de las Líneas 90, 120 y 157. La Pnueva en las Líneas 107 y 137 presentó valores bajos y se comportó como un parte-aguas entre las regiones norte y sur. Estacionalmente la Pnueva fue alta en la transición primavera-verano; disminuyó en el verano y el otoño, con aumento en invierno. La Pnueva se relacionó con el índice de surgencias costeras y se concluye que para un índice de surgencias costeras menor a 200 m3/s/100 m, la Pnueva aumenta y el máximo se produce en el mismo período que las surgencias costeras. Para un índice superior a 200 m3/s/100 m la Pnueva disminuye y ambas series se desfasan temporalmente
Ordenamiento Ecológico Marino en el Pacífico Norte mexicano: propuesta metodológica
The dynamic oceanic and coastal regionalization of the Mexican North Pacific in front of the Baja California Peninsula was proposed based on a temperature and new primary production model (Pnew). Pnew was calculated based on temperature AVHRR images; SeaWiFS chlorophyll and PAR sensor and total phytoplankton production (PPz) and the reason for each depthfz multiplied. Monthly temperature maps and Pnew were done for different depths: 0, 10, 30, 50, 75 and 100 m. This is the first marine regionalization using the concept of territorial regionalization. The results show the oceanographic dynamic in front of the Baja California Peninsula; this varied from the coast to the ocean in a latitudinal manner. For the regionalization of the Mexican North Pacific, nine Environmental Management Units (EMU) are being proposed: three oceanic and six coastal. The oceanic EMU VIII and the neighboring coastal areas IV and V are considered transition zones between the northern (subarctic waters) and the southern (tropical waters) conditions. In particular, the region of Isla Navidad stands out as the division between the cold northern waters and the warm waters to the south. In the spring, the effect of the coastal upwellings of the EMUs I and II is visible from the surface up to 100 m, with eutrophic zones in the coastal EMUs IV and V at 30-50m. In the fall, the area of study is oligotrophic.Se propone una regionalización oceánica y costera dinámica del Pacífico Norte mexicano frente a la Península de Baja California a partir de un modelo de temperatura y producción primaria nueva (Pnueva). La Pnueva se calculó con base en imágenes de temperatura del AVHRR; clorofila y PAR del sensor SaeWiFS y se multiplicó por la producción fitoplanctónica total (PPZ) y la razón-fz para cada profundidad. Se confeccionaron mapas mensuales de temperatura y Pnueva para profundidades de 0, 10, 30, 50, 75 y 100 m. Esta es la primera regionalización marina con el concepto de regionalización territorial. Los resultados muestran la dinámica oceanográfica frente a la Península de Baja California; ésta varió de lacosta al océano y de forma latitudinal. Para la regionalización del Pacífico Norte mexicano, se propone nueve Unidades de Gestión Ambiental (UGA): tres oceánicas y seis costeras. La UGA oceánica VIII y las vecinas costeras IV y V son consideradas zona de transición entre las condiciones norteñas (agua subártica) y las sureñas (agua subtropical). En particular, la región de Isla Navidad se destaca como divisoria entre el agua fría al norte y cálida al sur. En primavera, el efecto de las surgencias costeras de las UGAs I y II se distingue desde la superficie hasta 100 m, con zonas eutróficas en las UGAS costeras IV y V en 30-50 m. En otoño el área de estudio es oligotrófica
POR UNA CULTURA DE PAZ: UNA MIRADA DESDE LAS CIENCIAS DE LA CONDUCTA
En
virtud
de
lo
anterior,
los
estudiosos
de
las
ciencias
de
la
conducta
de
la
Universidad
Autónoma
del
Estado
de
México,
ante
la
persistencia
y
proliferación
de
estos
hechos
en
diversas
partes
del
Mundo
y
de
nuestro
país
en
particular, se
convocó
a
los
estudiosos
interesados
y
a
la
sociedad
en
general
a
presentar
trabajos
para
analizar,
debatir
y
proponer
estrategias
de
acción
y
dirección,
que
fortalezcan
una
convivencia y bienestar con sentido humanista para una cultura de paz.
El
presente
texto
es
producto
de
esta convocatoria
que
recoge
los
trabajos
de
los
interesados
en
la
temática,
de
diferentes
países
(España,
Argentina,
Cuba,
Brasil,
Costa
Rica
y
México)
retomando
con
ello
sus
experiencias
relativas
al
estudio,
análisis,
comprensión
e
instrumentación
de
la
cultura
de
paz
en
los
distintos
ámbitos
institucionales
en
los
que
participan:
educativo,
salud,
penitenciario,
social,
laboral,
familia,
alimentario,
psicológico,
por
mencionar
algunos.
El
presente
libro,
propicia
un
espacio
de
reflexión,
diálogo
y
posicionamiento
de
las
ciencias
de
la
conducta
para
la
apropiación,
análisis,
debate
y
propuestas
que
fortalezcan
una
cultura
de
paz
a
través
de
la
convivencia
y
el
bienestar
social
con
sentido
humanista.
El
sistema
económico
neoliberal
y
el
proceso
de
globalización
han
contribuido
al
logro
de
avances
significativos
en
la
ciencia
y
la
tecnología,
pero
también
han
propiciado
la
polarización
de
las
sociedades
lo
que
ha
impactado
de
manera
negativa
a
la
sociedad
en
su
conjunto,
pero
en
mayor
medida
a
los grupos
vulnerables. Dicha
polarización
ha
traído
consigo
un
desarrollo
desigual
del
mundo
que
se
expresa
de
diferentes
maneras
tanto
en
países
desarrollados
como
en
los
llamados
del
tercer
mundo,
en
donde
no
están
satisfechas
las
necesidades
humanas
elementales
de
todos
los
sectores
de
la
población,
siempre
falta
algo.
Si
a
esto
le
sumamos
los
conflictos
internacionales por
diferentes
motivos
que
enfrentan
algunas
naciones,
una
insuficiente
cobertura
educativa
y
de
salud,
desempleo
y
pobreza
extrema,
entre
otras
cosas;
estamos
frente
a
retos
de
gran
envergadura
para
los
gobiernos,
para
los
estudiosos
y
para
la
sociedad
civil
en
general. Uno
de
los
intentos
para
frenar
y prevenir
la
agudización
de
estas
problemáticas
es
la
cultura
de
paz,
cuyo
estudio
y propuestas
han
ido
avanzando
en
diferentes
sentidos
y
de
manera
favorable,
el
tema
está
presente
en
diferentes
Organismos
Internacionales
como
la
ONU,
la
UNESCO,
la
OCDE,
El
Banco
Mundial,
entre
otros.
Pero
falta
mucho
por
hacer.Universidad Autónoma del Estado de Méxic
una mirada desde las Ciencias de la Conducta
Este libro es el resultado de los trabajos presentados en el 1er Congreso Internacional "Convivencia y bienestar con sentido humanista para una cultura de paz"
Satellite derived photosynthetic pigment surveys: A review of marine phytoplankton biomass and productivity
El sensor Coastal Zone Color Scanner (CZCS) que voló a bordo del satélite Nimbus-7 proveyó datos de pigmentos fotosintéticos del océano entre 1978 y 1986. El procesado de los datos se terminó en 1990 y nos permitió apreciar la distribución global de la concentración de pigmentos y del coeficiente de atenuación vertical de luz, aunque su cobertura fue escasa. Los datos del CZCS representan una serie de tiempo única, y durante varios años serán la fuente principal para el estudio de la distribución de pigmentos en el océano y su variación interanual. Con el lanzamiento del SeaWiFS hacia el final de 1995, la comunidad de ciencias de la Tierra podrá contar con una serie de tiempo ininterrumpida de color del océano. Estos datos de satélite son la única forma de monitorear la productividad marina total y nueva en la escala de cuencas oceánicas. La productividad nueva es el componente critico que limita el transporte de COz de la superficie a las aguas profundas por la biota. Esto abre una nueva posibilidad para el estudio de los flujos de carbono en las escalas regional y global, y de días a años. Además, la variabilidad espacio/temporal de los pigmentos fotosintéticos que se aprecia en las imágenes del CZCS, también se ha usado como trazador superficial para describir fenomenología física, especialmente en áreas donde la temperatura superficial es homogénea. De la revisión presente es claro que aun hay mucho por hacer con la base de datos del CZCS.
doi: https://doi.org/10.22201/igeof.00167169p.1996.35.1.110
Nutrient and phytoplankton dynamics in a coastal lagoon strongly affected by coastal upwelling
San Quintín Bay is a coastal lagoon influenced by the California Current System (CCS) coastal upwelling. Upwelling brings nutrient-rich waters near the bay mouth and tidal currents propagate those waters throughout the bay. Upwelling intensification and relaxation events occur with a period of ~2 weeks, possibly due to the variability of circulation of the CCS. Off San Quintín, the CCS has an offshore component of the flux, causing upwelling intensification events as strong as off Point Conception (34.5°N), with high phytoplankton productivity. At the lagoon's mouth, upwelling is the main cause of variability for all physicochemical properties except temperature. Semi-diurnal tides are the main cause of variability for temperature. Nutrient remineralization at the sediments and turbulence induced by tidal currents and wind waves increase nutrient concentrations in the lagoon. At the heads of the bay, phytoplankton abundance was ten-fold lower, productivity and chlorophyll concentrations were three-fold lower, chlorophyll content per cell was three-fold higher, and turbidity was higher than at the mouth. The few available data suggest the hypothesis that the effect of ENSO events on phytoplankton biomass depends on the interdecadal regime shifts in the northeastern Pacific. At the lagoon's mouth and adjacent ocean, summer salinities as low as 32.4 suggest the arrival of water parcels that originate in the north, possibly the Columbia River estuarine plume