scholarly journals Age and growth of thread herring Opisthonema libertate, in the southern Gulf of California

2020 ◽  
Vol 48 (1) ◽  
pp. 15-22
Author(s):  
Jorge Payan-Alejo ◽  
Mercedes L. Jacob-Cervantes ◽  
Guillermo Rodríguez-Domínguez
Keyword(s):  
Environmental Conditions ◽  
El Niño ◽  
Gulf Of California ◽  
El Nino ◽  
Age Groups ◽  
Reproductive Period ◽  
Age And Growth ◽  
Chl A ◽  
Pooled Data ◽  
Schnute Model

To fit a growth model to Opisthonema libertate, the most common thread herring in a small pelagic fishery in the southern Gulf of California, size data of commercial landings and age were generated from sagittal otoliths assessed during three different years, 2005, 2008 and 2015, representing Neutral, La Niña and El Niño environmental conditions, respectively. A multimodel select approach on five special submodels of generalized Schnute model, including one, equivalent to the Von Bertalanffy model, were used. A total of 573 otoliths were analyzed; 219 from Neutral, 149 from El Niño and 205 from The Niña events. An opaque zone of otoliths formed in winter-spring when chlorophyll a (Chl-a) concentrations were at a maximum. However, a hyaline zone of otoliths formed during the summer of the reproductive period. Schnute submodel 1 was the best model selected in all three environmental conditions, but submodel 3 was the best on pooled data. Length of thread herring aged 0.5 years old in the El Niño year was lower than other environmental-years analyzed. A possible compensatory effect on growth with age was observed in the data because environmental conditions affected the growth of 0.5-year-old thread herring, as was evident in size variance in this age group under all three conditions, but variance decreased in the older age groups. Thus, a multimodel average of Schnute submodels 1 and 3 could be used to describe the growth of O. libertate in the southern Gulf of California.

scholarly journals Temporal Variability of Oceanic Mesoscale Events in the Gulf of California

2021 ◽  
Vol 13 (9) ◽  
pp. 1774
Author(s):  
Edgardo Basilio Farach-Espinoza ◽  
Juana López-Martínez ◽  
Ricardo García-Morales ◽  
Manuel Otilio Nevárez-Martínez ◽  
Daniel Bernardo Lluch-Cota ◽  
...  
Keyword(s):  
Interannual Variability ◽  
El Niño ◽  
Gulf Of California ◽  
Satellite Images ◽  
El Nino ◽  
Northern Region ◽  
Southern Region ◽  
Ocean Dynamics ◽  
Seasonal Behavior ◽  
Chl A

Oceanic mesoscale events such as eddies, coastal upwelling, filaments and fronts created by water mass intrusion present properties allowing them to concentrate, transport and disperse salt, nutrients and plankton, among other important constituents in the ocean. The use of satellite images enables the continuous monitoring of the ocean dynamics at different temporal and spatial scales, aiding the study of its variability. This study focuses on the identification of these mesoscale events in the Gulf of California (GC) by means of sea surface temperature (SST) and chlorophyll a (Chl a) fronts (edge) detection by processing 5-day satellite images from the 1998–2019 period. The annual occurrence or frequency and duration of each event was identified; the interannual variability was evaluated and underlying correlations with the Multivariate El Niño Index (MEI) and the Pacific Decadal Index (PDOI) were assessed via Principal Component Analysis. Most events showed a seasonal variability due to the seasonal behavior of forcing agents (i.e., Pacific Ocean and winds) that stimulate their formation or presence in the GC; seasonality was more evident in the northern region than in the southern region. The interannual variability of their frequency or duration was associated with strong and intense El Niño and La Niña conditions (positive or negative MEI values) together with positive or negative phases of the PDOI. The use of SST and Chl a satellite images with a 5-day temporal resolution allowed to better identify and quantify the annual frequency and duration of each mesoscale event. It allowed to detect a seasonal behavior of these events in the northern region, followed by the central region. The southern region, due to the interaction of different water masses with unique characteristics, exhibited a less evident seasonality in the frequency of eddies, and no apparent association between their interannual frequency and duration with the MEI and PDOI. Constantly monitoring these oceanic events and their variability will help in the understanding of how the different regions of this large marine ecosystem respond to these variations in the long term.

Changes in the Spawning Environment of Sardinops caeruleus in the Gulf of California during El Niño 1997–1998

2002 ◽  
Vol 54 (2) ◽  
pp. 207-217 ◽  
Author(s):  
L Sánchez-Velasco ◽  
J.E Valdez-Holguı́n ◽  
B Shirasago ◽  
M.A Cisneros-Mata ◽  
A Zarate
Keyword(s):  
El Niño ◽  
Gulf Of California ◽  
El Nino

The 1982–1984 El Niño in the Gulf of California as seen in coastal zone color scanner imagery

1994 ◽  
Vol 99 (C4) ◽  
pp. 7423 ◽  
Author(s):  
Eduardo Santamaría-del-Angel ◽  
Saúl Alvarez-Borrego ◽  
Frank E. Müller-Karger
Keyword(s):  
Coastal Zone ◽  
El Niño ◽  
Gulf Of California ◽  
El Nino ◽  
Color Scanner

scholarly journals ESTIMACIÓN DE LA PRODUCTIVIDAD PRIMARIA DURANTE OTOÑO-INVIERNO EN LA BAHÍA DE LA PAZ, B.C.S., MÉXICO

2008 ◽  
Vol 23 (1-2) ◽  
pp. 45
Author(s):  
G. Verdugo-Díaz ◽  
M. O. Albáñez-Lucero ◽  
R. Cervantes Duarte
Keyword(s):  
Chlorophyll A ◽  
Primary Productivity ◽  
El Niño ◽  
Gulf Of California ◽  
El Nino ◽  
Cold Season ◽  
Maximum Temperature ◽  
La Paz ◽  
Average Maximum ◽  
Average Maximum Temperature

Se analizó la variabilidad de la productividad primaria en Bahía de La Paz, durante noviembre de 1997 y 2000, enero de 1998 y febrero de 2001. Se identificó Agua del Golfo de California en mayor proporción; Agua Superficial Ecuatorial y Agua Subsuperficial Subtropical. En noviembre de 1997 se registró el valor promedio máximo de temperatura (~27.62 °C) y en febrero el valor mínimo (~19.16 °C). El índice de Simpson (Ö) indicó que durante noviembre de 1997 (~286.6 J m-3) la columna de agua presentó mayor estratificación, mientras que en noviembre de 1998 (~60.4 J m-3) y febrero de 2001 (~94.5 J m-3) se encontró mezclada. En noviembre de 1997 se registraron bajos valores de nitratos (~1.52 µM), nitritos (~0.04 µM) y clorofila a (~0.44 mg Cla m-3). En febrero de 2001 se registraron valores mayores de nitratos (~7.46 µM), nitritos (~0.76 µM) y clorofila a (~1.07 mg Cla m-3). La productividad primaria superficial e integrada presentaron sus promedios máximos en noviembre de 2000 (~5.09 mg C m-3 h-1 y 75.54. mg m-2 h-1) y mínimos en noviembre de 1997 (~2.93 mg C m-3 h-1 y ~55.29 mg m-2 h-1), respectivamente. De acuerdo a investigaciones anteriores, los valores reportados de productividad son característicos de la temporada fría de la bahía con excepción de noviembre de 1997, que presentó influencia de El Niño. Primary productivity stimation during autumm-winter in Bahía de La Paz, B.C.S., Mexico We analyzed the variability of primary productivity in Bahía de La Paz during November 1997 and 2000, January 1998 and February 2001. Water was identified in the Gulf of California in higher proportion; Surface Water and Water Subsuperficial Equatorial Subtropical. In November 1997 we saw the average maximum temperature (~ 27.62 ° C) in February and the lowest value (~ 19.16 ° C). The index of Simpson (Ö) indicated that during November 1997 (~ 286.6 J-3 m) column of water with greater stratification, while in November 1998 (~ 60.4 m J-3) and February 2001 (~ 94.5 J m-3) was mixed. In November 1997 there were low values of nitrate (~ 1.52 µM), nitrites (~ 0.04 µM) and chlorophyll a (Cla ~ 0.44 mg m-3). In February 2001, there were larger values of nitrate (~ 7.46 µM), nitrites (~ 0.76 µM) and chlorophyll a (Cla ~ 1.07 mg m-3). The primary productivity and integrated surface presented their highest averages in November 2000 (C ~ 5.09 mg m-3 h-1 and 75.54. mg m-2 h-1) and minimum in November 1997 (C ~ 2.93 mg m-3 h-1 and ~ 55.29 mg m-2 h-1), respectively. According to previous research, reported productivity values are characteristic of the cold season of the bay with exception of November 1997, which showed influence of El Niño.

Water masses and chlorophyll-a distribution in a semi-enclosed bay of the southern Gulf of California, Mexico, after the “Godzilla El Niño”

2019 ◽  
Vol 12 (15) ◽  
Author(s):  
Erik Coria-Monter ◽  
María Adela Monreal-Gómez ◽  
David Alberto Salas de León ◽  
Elizabeth Durán-Campos
Keyword(s):  
Chlorophyll A ◽  
El Niño ◽  
Gulf Of California ◽  
El Nino ◽  
Water Masses ◽  
Enclosed Bay ◽  
Chlorophyll A Distribution

Introduction

2011 ◽  
Author(s):  
David Beresford-Jones
Keyword(s):  
Human Impact ◽  
Cultural Change ◽  
Environmental Conditions ◽  
El Niño ◽  
El Nino ◽  
Prima Facie ◽  
South Coast ◽  
Archaeological Remains ◽  
Prima Facie Case

This introductory chapter first sets out the book's purpose, which is to present a new archaeological case for prehistoric human impact on the environment: a study of ecological and cultural change from the arid south coast of Peru, beginning around 700 bc and culminating in a collapse by about ad 1000. Its focus is the lower Ica Valley, today largely depopulated and bereft of cultivation, but whose abundant archaeological remains attest to substantial prehistoric occupations and thereby present a prima facie case for changed environmental conditions. This is a place of extreme environmental juxtaposition: one of the world's oldest and driest deserts, crossed by lush riverine oases, and sporadically impacted by El Niño floods or long droughts. An overview of the subsequent chapters is also presented.

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