Papers by Victor Camacho-Ibar
Journal of Marine Science and Engineering, Jul 18, 2020
Estuaries and Coasts, Feb 6, 2019
Organic Geochemistry, Mar 1, 2003
Fatty acids were determined in three sediment cores from Delfin Basin, Northern Gulf of Californi... more Fatty acids were determined in three sediment cores from Delfin Basin, Northern Gulf of California (NGC), Mexico. Steady-state apparent degradation rate constants (k′) were determined to assess the reactivity of the total organic carbon (TOC) pool, the total fatty acids (TFA) and selected individual fatty acids. k′ values for TFA were higher than those for TOC, indicating that fatty acids
Regional Studies in Marine Science, Sep 1, 2022
We report the seasonal variability of temperature, nutrients, and total and size‐fractionated chl... more We report the seasonal variability of temperature, nutrients, and total and size‐fractionated chlorophyll‐a (Chl‐a) in nearshore waters off northern Baja California (nBC), under conditions of the marine heatwave and El Niño that occurred in the northeastern Pacific during 2014–2015. Compared with the mean annual cycle (2008–2015), our study period was characterized by warmer waters, nitrate‐impoverished, and with very low Chl‐a concentration, which was closely associated with strong stratification and reduced upwelling conditions off nBC. Temperature anomalies were >2.0°C by the end of 2014 when the marine heatwave prevailed, decreased during the spring‐early summer upwelling season of 2015, and returned to >2.5°C by the end of 2015 when El Niño appeared along the coast of nBC. As in 2008–2012 and closely coupled with upwelling, a seasonal cycle of total Chl‐a was recorded under these abnormally warm conditions. However, relative to the mean annual cycle, total Chl‐a and nitrate concentrations were significantly reduced (19%–55% and 40%–81%, respectively), with negative anomalies throughout the study period. Moreover, the seasonal evolution of the size‐fractionated Chl‐a concentration showed that smaller cells (<5 μm) systematically contributed with the largest fraction (>60%) of the total Chl‐a. Our findings indicate that the sequential occurrence of the marine heatwave in 2014 and El Niño in 2015 had a significant and sustained impact limiting the nitrate supply and reducing the total Chl‐a in nearshore waters off nBC. In conclusion, our data reveal that a shift toward an oligotrophic state occurred in coastal waters off nBC during the warm period of 2014–2015.
Environmental Pollution, Jul 1, 2006
Continental Shelf Research, Nov 1, 2004
Ecological studies, 2001
Baja California, between 32°30′N, 117°W and 23°N, 110°W, is a 1300-km-long and 30- to 240-km-wide... more Baja California, between 32°30′N, 117°W and 23°N, 110°W, is a 1300-km-long and 30- to 240-km-wide peninsula, which is flanked by the Pacific Ocean in the west and the Gulf of California in the east. The continental shelf along the Pacific coast of Alta and Baja California (42–22.9°N) is typically narrow (usually <20 km) but widens to 50–70 km in the central and southern embayments. The coastal geomorphology is composed of faultline, dunes, elevated wave-cut benches, barrier beaches, islands, spits, and bay barrier coasts. Numerous and extensive, mainly sandy plains and valleys occur along the coast, and muddy marsh flats can be found at the mouth of the streams. Coastal lagoons and estuaries represent a small part of the coastline and are partially protected by bay-mouth sand spits (Wiggins 1980).
Ecological Engineering, Sep 1, 2017
Science Advances, Mar 15, 2023
Ventilation in the deep Gulf of Mexico (GoM), its connection to the North Atlantic, and its susce... more Ventilation in the deep Gulf of Mexico (GoM), its connection to the North Atlantic, and its susceptibility to changes of the Atlantic Meridional Overturning Circulation are investigated by combining observations of radiocarbon and volume transport with a Coupled Model Intercomparison Project phase 6 (CMIP6) General Circulation Model (GCM) ensemble output. Radiocarbon data and multiannual volume transport through the Yucatan Channel suggest deep water residence times ~100 years for the GoM. Comparisons to previous radiocarbon observations suggest that the deep GoM has aged in the recent past, consistent with observed raising temperatures and the CMIP6 GCM simulations. The distribution of radiocarbon indicates a time frame of ~160 years between North Atlantic convection and complete ventilation of the deep GoM. This suggests that aging and warming of GoM deep waters were initiated in the North Atlantic before ~1890 consistent with reported rapid and persistent AMOC weakening since the Little Ice Age.
Remote Sensing, Mar 16, 2021
Estuaries and Coasts, 2014
Estuaries and Coasts, Oct 26, 2016
Ciencias Marinas, Mar 17, 2023
Journal of Marine Systems, 2022
Ciencias Marinas
Con el propósito de determinar la biomasa y la composición del fitoplancton (picofitoplancton, na... more Con el propósito de determinar la biomasa y la composición del fitoplancton (picofitoplancton, nanodiatomeas y microdiatomeas) bajo condiciones oligotróficas, se realizó un estudio en la capa superficial de la cuenca de Guaymas, golfo de California, durante el verano tardío de 2016. El estudio contempló la medición de variables hidrográficas, químicas y biológicas en la capa superficial del área de estudio. Nuestros resultados mostraron una columna de agua cálida, fuertemente estratificada, empobrecida en nutrientes y con biomasas fitoplanctónicas reducidas (<1 mg Cla·m–3). Los cocientes promedio de N:P (0.55 ± 1.34), N:Si (0.13 ± 0.18) y Fe:N (52.70 ± 29.70) indicaron condiciones de limitación por N. La contribución de los grupos fitoplanctónicos a la biomasa fluctuó ampliamente por nivel de profundidad, y se observó el predominio del picofitoplancton (85.0 ± 2.7%) en superficie (5 m) y de las nano-microdiatomeas (91.5 ± 5.9%) en el nivel más profundo (35-40 m), adyacente a la ...
Biogeosciences Discussions, 2019
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Papers by Victor Camacho-Ibar
Results will be presented showing not only a strong interannual variation on nutrient supply to SQB between spring 2004 and spring 2005, but also a sharp latitudinal contrast on nutrient availability along the California Current system during spring 2005. As registered within SQB, in spring 2005 coastal waters off the north of the Baja California peninsula showed a nutrient enrichment associated with a positive anomaly on upwelling intensity. By contrast, during the same period a delay in the onset of upwelling conditions in the north of the California Current system caused anomalously low nutrient concentrations in that region. Positive chlorophyll-a anomalies during May-June 2005 were observed not only off SQB, but in the whole of northern part of the Baja California peninsula. Nitrate budgets using a box-model indicate that the supply of nitrate from the ocean to SQB was three times higher in spring 2005 than in spring 2004, showing that the supply of nutrients from the ocean to coastal lagoons and estuaries along the NE Pacific coast can have intense interannual variations related not only to El-Niño / La Niña conditions.