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La Paz Bay, in the southwestern Gulf of California (inset). The gray star in the main panel indicates the position of the oceanographic station and the site of the sediment trap in the deepest part of the bay (~410 m)
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La Paz Bay is a distinct region within the Gulf of California whose rich cetacean community exhibits an intense annual overturn. We studied the environmental conditions that could drive this change over the course of a year. Cetacean biomass was estimated from monthly surveys, with concurrent collection of water-column measurements of temperature,...
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... most productive areas of the Gulf of California (hereafter 'the gulf'; Fig. 1) are located along its east- ern (continental) side and in the northern region due to winter upwelling and tidal mixing, respectively (Lluch-Cota 2000). The southwestern gulf (peninsu- lar side) is comparatively less produc tive, except for La Paz Bay (hereafter 'the bay'), whose photosyn- thetic pigment concentrations remain high ...
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... Paz Bay is the largest and deepest embayment in the Gulf of California (Fig. 1), with an area of ~2160 km 2 and a maximum depth of ~410 m. Water exchange with the surrounding gulf occurs mainly through the northern channel, called Boca Grande (Salinas- González et al. 2003, Obeso-Nieblas et al. 2004). The bay lies within a tropical-subtropical tran- sition zone that seasonally alternates between 2 well- defined ...
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... influence on the base of the food web, through nutrient supply, help us to identify the predominant ecological conditions that attract differ- ent cetacean species at different times of the year. A number of physical, chemical, and biological vari- ables were measured at an oceanographic station located over the deepest part of the bay (~410 m; Fig. 1). Between 17 February 2007 and18 February 2008, 13 CTD profiles were taken to depths ranging from 50 to 340 m. Temperature, salinity, and density data were standardized to 1 m depth means. From these values, we computed the Brunt-Väisälä fre- quency (cycles h −1 ; also known as buoyancy fre- quency), a measure of the degree of ...
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... (Bishop 1988, Silver & Gowing 1991, Silverberg et al. 2006), which could trigger the incursion of different cetacean species according to their feeding require- ments. We analyzed samples from a Technicap ® PPS 3/3 trap of 0.125 m 2 aperture, which was anchored and suspended at ~310 m depth at the same site as the oceanographic measurements (Fig. 1). The sink- ing matter was collected in separate bottles during 7 to 15 d periods each and then fixed with a preser - vative solution of 4% buffered formaldehyde satu- rated with sodium tetra borate. The total mass flux, in g m −2 d −1 , was estimated from 4 sub-samples, which were centrifuged for 25 min at 3000 rpm (~1600 × g), ...
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Citations
... The exception to this could be the colony of Los Islotes, which was the only one that has shown an increase. This could be related to the fact that this colony is in a region with a high biological production yearround due to a mesoscale gyre that is important in summer (Martínez-López et al. 2001;Pardo et al. 2013), providing a high prey availability for the colony (Adame-Fernández et al. 2020). Likewise, the formation of fronts is typical at the entrance of the Gulf of California, which is significant for fish production in the region (Álvarez-Borrego 1983). ...
The California sea lion (Zalophus californianus) population in the Gulf of California has shown a significant abundance decline. However, its 13 breeding colonies have distinct individual dynamics modulated by regional environmental conditions. Thus, the relationship between environmental variability and population growth is complex and must be analyzed regionally. Los Islotes is the only colony that has steadily increased since the 1980s. The goal of this study was to determine the interannual changes in abundance and foraging habits (trophic breadth/habitat use) of adult females, and the interannual abundance and body mass of pups of the California sea lion colony from Los Islotes (Southwest Gulf of California) and its relationship with anomalous warming events. For this purpose, monthly population counts were carried out during the breeding seasons (2013–2018) and their interannual variability was analyzed. In addition, 152 pups were captured and weighted, and a small portion of hair was sampled to analyse the stable isotopes of nitrogen (δ¹⁵N) and carbon (δ¹³C) to obtain annual isotopic areas with the program R (SIBER routine). A 50–60% decrease in pups abundance was documented in warm years, such as 2014 and 2015, compared to 2013. Furthermore, pup body mass was negatively affected (by around 3 kg) during anomalous warming events in 2014 and 2018. The largest isotopic areas (3.18‰² and 2.88‰²) were observed in 2016 and 2018, as a probable result of greater dispersion of adult females during their foraging trips. These results suggest adult females show adaptive responses to environmental variability. It is relevant to continue monitoring and understanding the dynamics of this colony, especially under current environmental change scenarios.
... The Gulf of Aqaba (length: 160 km) which opens at Straits of Tiran between the Sinai and Saudi Arabia, terminating in the North at Eilat (Israel) and Aqaba (Jordan), the short Gulf of Corinth (length: 127 km), a semi-enclosed embayment in central Greece between mainland Greece in the North and the Peloponesse in the South, and the Gulf of California (length: 1,126 km) which has more than double length of that of the reconstructed Upper Rhine Graben are examples of similar structured long and narrow gulfs like the late Rupelian Upper Rhine Gulf. One can conclude, although evaluation methods varied, that the larger the extension and volume of the gulf is, the higher is the number and frequency of species in that water body (see Pardo et al. 2013;Bearzi et al. 2016;Costa et al. 2019). Therefore, cetaceans would under these premises also have been expected in the deposits of the Upper Rhine Graben. ...
Despite two centuries of fossils collecting, no cetacean remains from the Oligocene marine deposits of the Mainz Basin (western Germany) have ever been reported. Here, we describe a possible mysticete tooth from the sand pit of Eckelsheim, which exposes high energy deposits belonging to the Rupelian Alzey Formation. The latter has yielded a rich assemblage of vertebrates and invertebrates, but so far, only one marine mammal in the form of the sirenian Kaupitherium . The whale tooth in some ways resembles the m2 of Llanocetus from the latest Eocene of Seymour Island, Antarctica. If the find from the Mainz Basin is not a regionally evolved form, Llanocetus , which is known from the South Atlantic, could have migrated through the Atlantic realm during the early Oligocene. It cannot be excluded that the tooth represents a more widely occurring lineage, neither endemic nor necessarily related to llanocetids, that—given the generally poor Rupelian record—has not been well documented yet.
... The bay is considered one of the most highly productive areas in the southwestern GC and was recently established as a Priority Marine Region, including the protected natural wildlife area of the Espíritu Santo Archipiélago (SEMARNAT, 2014). The bay supports many species of ecological importance, as well as marine mammal populations such as whales, dolphins, sea lions, turtles, seabirds, and filter feeding marine fauna (Pardo et al., 2013;Adame et al., 2020;Whitehead et al., 2019). The northern part of the bay (deeper sector) is connected to the GC by a ~400-m-deep sill (north mouth), zone of water exchange with the gulf through the north mouth of LPB. ...
... The MLD time-longitude section (Fig. 5c) shows a considerable MLD with high values (50-70 m), and ~30 m differences between BLPZ and the GC vicinity during winter. Low MLD values (~20 m) were showed from April to September 2015 and correspond to the period with a thin mixed layer and strong stratification reported by Salinas-González et al. (2003), Obeso-Nieblas et al. (2004) and Pardo et al. (2013). At the end of 2015 (October to December) prior to the peak of the winter El Niño condition, a pronounced temporal gradient was evidenced, with MLD values reaching ~ 40-70 m and no differences between LPB and the GC vicinity. ...
... Los altos índices de Chl-a observadas durante un ciclo anual en la BLPZ, se mantienen gracias al patrón de circulación y forzamiento del viento presentes en la bahía, aunado a su aislamiento natural, protegida de forma natural por grandes islas, islotes y cadenas montañosas cercanas a la costa, sin el aporte de ríos ni el efecto antropogénico asociado a grandes asentamientos humanos. Lo anterior hace que la bahía, sostenga una diversa megafauna, incluyendo al menos 16 especies de cetáceos con afinidades subtropicales y templadas (Pardo et al., 2013 (Milton et al., 1994 5. Panel superior: Vectores mostrando los cambios en la dirección del viento durante el paso de la T. T. Lidia (29 de agosto al 01 de septiembre de 2017) en SEV, POR, y CIB (la punta del vector indica la dirección de donde sopla el viento). El panel inferior muestra el esquema de rosa del viento del condensado de datos de velocidad y dirección del viento de SEV, POR, y CIB durante el mismo período. ...
En este artículo se muestra como Estaciones Meteorológicas Autónomas (EMAs) instaladas en la zona costera de la Bahía de La Paz (BLPZ), registraron el paso de 2 ciclones tropicales (CT); Lidia (29 de agosto al 2 de septiembre de 2017) y Lorena (21 de septiembre de 2019) y su efecto sobre el patrón de viento y la productividad biológica de la BLPZ. Las EMAs ubicadas en el sur y centro de la bahía, registraron las mayores velocidades y rachas de viento (~23 y 30 m s-1) durante el paso de ambos CTs y direcciones predominantes del primer, segundo y tercer cuadrante. Las imágenes semanales del satélite MODIS-Aqua de Clorofila a superficial (Chl-a), mostraron un incremento en los valores de Chl-a (> 3 mg m-3) en BLPZ después del paso de Lidia y Lorena.Tanto las imágenes de satélite como las observaciones registradas por las EMAs, aportan información valiosa para la toma de decisiones, en la prevención de riesgos, sustentabilidad, aprovechamiento de energías renovables e incentivan el monitoreo de los ecosistemas costeros como la mejor forma de evaluar los impactos de los CTs en áreas de gran valor ecológico como la BLPZ.
... Fluctuations in cetacean distribution, abundance and habitat preferences may be observed across years [10,11], as well as across seasons [12][13][14][15], depending on the spatio-temporal scales of relevant processes [16]. There is some evidence of short time-scale movements [17], but poor understanding of the relationship between such infra-seasonal movements of populations and environmental conditions [18,19], inasmuch as the dynamics of spatial distributions at this temporal scale are at best poorly documented for most top predators. This is mostly due to the paucity of information about the whereabouts of top pedators, and in particular cetaceans, at fine scale, both spatially and temporally. ...
Cetaceans adjust their distribution and abundance to encountered conditions across years and seasons, but we poorly understand such small-scale changes for many species, especially in winter. Crucial challenges confront some populations during this season, such as the high levels of fisheries-induced mortality faced by the common dolphin (Delphinus delphis) in the Northeast Atlantic shelves. For such species, understanding the winter fine-scale dynamics is crucial. We aimed to identify the dolphin distribution drivers during the winters of 2020 and 2021, with a focus on determining the lag between changes in oceanographic conditions and dolphin distribution. The changes were related to temporal delays specific to the nature and cascading effects that oceanographic processes had on the trophic chain. By determining the most important conditions and lags to dolphin distributions, we shed light on the poorly understood intrusions of dolphins within coastal waters during winter: they displayed a strong preference for the coastal-shelf waters front and extensively followed its spatial variations, with their overall densities increasing over the period and peaking in March-April. The results presented here provide invaluable information on the winter distribution dynamics and should inform management decisions to help reduce the unsustainable mortalities of this species in the by-catch of fisheries.
... Temperature was the only variable related to seasonal productivity patterns, because Chl was excluded due to collinearity (Zuur, Ieno & Elphick, 2010;Dormann et al., 2013). Similarly to SST, Chl is not affecting marine mammals directly, but it is often considered in models as a productivity index of the ecosystem (Redfern et al., 2006;Salvadeo et al., 2009;Pardo et al., 2013;Lopes, 2017). Another indirect variable was the moon phase. ...
Marine mammals in subtropical coastal habitats are sentinels of the health of the ecosystem and offer important ecosystem services. They rely on prey that pursues feeding opportunities, while both avoid unfavorable conditions. In many cases, these predator-prey dynamics fluctuate seasonally and are regulated by lunar, tidal, and/or diel cycles (hour). However, these rhythmical patterns may vary under different seasonal conditions. Bottlenose dolphins (Tursiops truncatus) in the Ensenada de La Paz in Baja California Sur, Mexico, were detected acoustically over the course of an annual cycle on 21 separate occasions, covering 640 h from June 2017 to May 2019. The presence of bottlenose dolphins was examined using Generalized
Additive Models (GAM) including variables that are related directly to their habitat (direct variables: hour, distance, depth) and to their prey (indirect variables: SST, moon
phase and tides). Seasonal differences in the presence of bottlenose dolphins were influenced more by indirect variables (explained deviance: 34.8% vs. 37.7%). Hourly acoustic detections occurred less frequently when SST exceeded 27.4 �C (Aug–End of
Nov.) and more frequently at moderate temperatures (22.7 �C to 26.3 �C) in May through July. Moreover, bottlenose dolphins were detected more frequently during waning and new moon phases, at the onset of flood and ebb tides, and during day (04:00 to 20:00). The seasonal differences in acoustic detections rates were highlighted
by the global GAM and hierarchical clustering. The strong seasonal pattern indicated possible interactions with rhythmic pattern of bottlenose dolphins. Four candidate variables (SST, moon, tide, and hour) were tested for plausible interaction terms
additional to their individual consideration, out of which only hour changed significantly between seasons. The patterns of presence likely increase feeding opportunities or may favor other behaviors such as socializing, resting, or nursing. These might prove responsible for the distinct occurrence and hourly patterns of bottlenose dolphins.
... Climate-driven changes to the physical-chemical properties of the water column alter biological productivity and food availability in marine ecosystems affecting the trophic web including top predators (Camphuysen et al., 2006). Thus, spatial and temporal distribution patterns of common bottlenose dolphin (Tursiops truncatus) populations are influenced by such environmental variations (Ballance, 1992;Defran and Weller, 1999;Baird et al., 2009;Bearzi et al., 2009;Pardo et al., 2013;Sprogis et al., 2018). The continuous presence of this species in highly productive areas, such as coastal lagoons and river mouths, has been well documented, in which individual home ranges are somewhat well defined and populations are well-structured (Ballance, 1992;Reza-García, 2001;Morteo et al., 2004;Rodríguez-Vázquez, 2008). ...
... The fastLSA time-series analyses on SST and Chl-a data highlighted the importance of local and regional oceanographic features that alter biomass production, resulting in a lagged response of 22 -29 days for the array of physical-chemical processes in the water column (Pardo et al., 2013;Kämpf and Chapman, 2016). This pattern has been documented in other neighboring areas in the Pacific such as Bahía de Banderas, Jalisco-Nayarit (Cerrillo-Espinosa and Barraza-Figueroa, 2007;Rodríguez-Vázquez, 2008), and the southwestern Atlantic (Moraes et al., 2012). ...
... It is also noteworthy that, although dolphin RA seemed to respond to these environmental changes within a week, higher RA could represent an influx of offshore bottlenose dolphins into the area, or that the same individuals remained in the study area and were encountered multiple times during a given survey. Even with these potential uncertainties, larger dolphin aggregations and higher residency times during upwelling periods are well-known in the GoC (Reza-García, 2001;Pardo et al., 2013;Guevara-Aguirre and Gallo-Reynoso, 2015), and the Mexican North Pacific (Morteo et al., 2004) Orozco et al., 2005;Kessler, 2006;López-Sandoval et al., 2009;Kono-Martínez et al., 2015) and the opposite occurred during El Niño conditions (especially in 2010), which has also been observed in other regions of the Pacific (e.g. Sprogis et al., 2018). ...
Despite being one of the most common odontocetes off Sinaloa (Mexican Pacific coast), basic studies on the ecology of common bottlenose dolphins (Tursiops truncatus) are scarce in the region. This study aimed to describe changes in the relative abundance, group size, and behavior of this species during 2007 – 2012. We used boat-based surveys and satellite images of sea surface temperature (SST) and chlorophyll-a (Chl-a) to model changes in dolphin relative abundance (RA) over time, using correlations in time series analyses. Overall, mean RA was 3.6 dolphins h-1 (SD = 8.0), and significantly higher RA (6.4 –16.7 dolphins h-1) occurred in 2008, 2011, 2012, which was concurrent with hydrographic effects of La Niña oceanographic conditions, as well as during the upwelling season (February – April) (SST: 17.3 – 25.0 °C; Chl-a: 3.7 – 21.4 mg m-3). Conversely, significantly lower RA values (0.5 – 3.8 dolphins h-1) occurred in 2007 and 2010 that were likely associated with El Niño effects on the biological productivity of the area (Chl-a: 0.3 – 7.6 mg m-3). We found significant correlations between monthly Chl-a and SST average values with mean bottlenose dolphins RA, and lags (22 – 29 days) in the trophic response to variations of the hydrographic parameters. Significantly larger dolphin groups were recorded during La Niña years possibly because of the higher availability of their prey. This hypothesis is supported by higher feeding frequencies (35 – 73%) observed during the upwelling seasons, especially during La Niña conditions, whereas the most frequent behavior throughout all other years was traveling (28 – 69%). Our results show that RA and group size of bottlenose dolphins inhabiting the waters off Sinaloa, Mexico, are likely influenced by the changes in hydrographic parameters, especially during extreme climatic events.
... This coincides with the pattern found in coastal waters of Panama, where the higher spotted dolphin sighting rate during the rainy season was associated with offshore movements and a scattered distribution that favored the availability of pelagic prey (García and Dawson 2003). Additionally, Pardo et al. (2013) indicated that odontocetes in the Gulf of California could be taking advantage of the coastal spawning season of pelagic fish species, which happens during periods of high SST, and this phenomenon is likely occurring in the MCP. In the Gulf of California the distribution and abundance patterns of bottlenose dolphins resemble those described here for spotted dolphins, with increased abundances being associated with warm and less productive periods and dolphin movements to deeper waters (Flores-Ramírez et al. 1996, Salvadeo et al. 2009). ...
... Esto coincide con el patrón encontrado en las aguas costeras de Panamá, donde una tasa de avistamiento mayor de delfines moteados durante la temporada de lluvias se asoció con los movimientos de los delfines en alta mar y una distribución dispersa que favoreció la disponibilidad de presas pelágicas (García y Dawson 2003). Además, Pardo et al. (2013) indicaron que, dentro del golfo de California, los odontocetos podrían estar aprovechando la temporada de desove costero de las especies de peces pelágicos, que ocurre durante los periodos de TSM alta, y es probable que este fenómeno esté ocurriendo dentro del PCM. En el golfo de California, los patrones de distribución y abundancia de los delfines nariz de botella se asemejan a los descritos aquí para los delfines moteados, con un aumento en la abundancia asociado con periodos cálidos y menos productivos y movimientos de delfines hacia aguas más profundas (Flores-Ramírez et al. 1996, Salvadeo et al. 2009). ...
Influence of environmental variability on the distribution and abundance of the pantropical spotted dolphin (Stenella attenuata) in the Mexican Central Pacific Influencia de la variabilidad ambiental sobre la distribución y la abundancia del delfín moteado pantropical (Stenella attenuata) en el Pacífico central mexicano Abstract. The Mexican Central Pacific (MCP) has complex oceanographic dynamics, with a well-defined seasonal pattern and influence of interannual sea surface temperature anomalies. The present study investigated the relationship between the distribution/abundance of spotted dolphins and the environmental conditions in the MCP. Dolphin sighting data were collected during January 2010-December 2015; distance to coast, sea surface temperature, and chlorophyll a (Chla) were obtained for each sighting location through georeferenced maps and satellite images. A total of 746 spotted dolphin sightings were obtained with a survey effort of 31,695 km. Spotted dolphins in the MCP showed a predominantly coastal distribution regardless of environmental conditions. Significant differences were detected concerning regional seasonal variation, with higher mean sighting rate during the stratified periods and higher density/abundance estimates during the mixed periods. Spotted dolphins showed preference for warmer conditions, with higher mean sighting rate, abundance, and distance to coast during the neutral and warm interannual periods. During the coolest conditions (cold periods), mean sighting rate and abundance decreased and spotted dolphins were located closer to the coast, where Chla concentration increased. These results suggest that changes in the distribution/abundance of these dolphins could be associated with habitat quality related to tropical (El Niño/Southern Oscillation) and extratropical (The Blob) oceanographic phenomena, which could be modulating their foraging activities.
... Indeed, the presence of mesoscale eddies induces vertical mixing and increases the supply of nutrients to the surface layers, which in turn induces high phytoplankton concentration and thereby supports the zooplankton biomass (Salas de León et al., 2011). The Bay of La Paz, the largest basin in the southern Gulf of California, provides a suitable habitat to many species, such as cetaceans, throughout the year, making it a hot spot for productivity (Pardo et al., 2013). The circulation pattern in the bay is dominated by the presence of a quasi-permanent mesoscale cyclonic eddy, which makes the region an interesting area in which to analyze the impact of physical forcing on planktonic organisms. ...
Marine zooplankton play a pivotal position in the pelagic ecosystem and, as one of their principal members, copepods represent by far the most significant direct link between phytoplankton and the higher trophic levels. In this study, observational evidence of the effect of a mesoscale cyclonic eddy on the abundance of copepods (adult calanoids, adult cyclopoids and all copepodite stages) in the Bay of La Paz, southern Gulf of California, a region recognized as exhibiting high biodiversity, is presented. During a multidisciplinary research cruise in February 2006, high-resolution hydrographic profiles were obtained from a grid of stations throughout the bay, and oblique zooplankton hauls were made in its north-central portion. The results showed the presence of a mature mesoscale cyclonic eddy, which extended to 110 m depth and 30 km diameter, reaching a surface azimuthal velocity of 20 cm s–1 at its periphery. Below the mixed layer at 50 m depth this eddy induced a cold-core water dome (∼16.25 ºC) at its center. Within this cold water dome, nutrients concentrations were much higher than outside the eddy. Nitrate reached up to 15 μM, soluble reactive phosphorous (SRP) up to 1.6 μM, and soluble reactive silicate (SRSi) up to 30 μM within the eddy. The total abundance of the organisms analyzed varied according to group: the calanoid copepods reached values of 8112 ind 100 m–3, the cyclopoid copepods of 4281 ind 100 m–3, and the highest abundance was recorded by all copepodite stages, of 32,076 ind 100 m–3. The influence of the cyclonic structure on copepod abundance was to induce the formation of a circular shape around the eddy periphery, which could be called a ‘copepod belt shape’. We suggest that several mechanisms induce this aggregation, including: 1) the affinity of these organisms for waters with a favorable temperature, and 2) the availability of food (phytoplankton) generated by the presence of the cyclonic eddy and the sub-mesoscale processes there, as well as by the presence of a bathymetric sill. These results represent the first observational report on the influence of a mesoscale cyclonic eddy in the Bay of La Paz on zooplankton organisms in winter, which should contribute to a better understanding of the dynamics of this highly productive area.
... En la Bahía de La Paz (BLP) y sus aguas adyacentes los cetáceos han sido estudiados en diferentes escalas espaciotemporales, tanto en aproximaciones a nivel de especies individuales como de ensamblaje de especies (Chávez Rosales, 1995;Pardo, 2009;Salvadeo, 2008;Salvadeo et al., , 2011Vázquez Morquecho, 1997). De las 27 especies de cetáceos documentadas para la BLP, tres se consideran residentes durante todo el año: el delfín común de rostro largo (Delphinus delphis bairdii), recientemente reclasificado en 2016 como (D. delphis bairdii); la tonina (Tursiops truncatus) y el rorcual tropical (Balaenoptera edeni), aunque sus abundancias cambian en el tiempo Pardo et al., 2013;. La alta riqueza de especies observadas en la BLP se debe, al igual que lo observado para la porción suroeste del GC, al ingreso de especies con hábitos migratorios definidos, como por ejemplo las ballenas azules y las ballenas jorobadas, o bien a la presencia de especies que responden a cambios en la distribución de sus presas, como el rorcual común Pardo, 2009;. ...
... Así, la heterogeneidad ambiental, incluida la diversidad de hábitats (p.ej. bentóniconeríticos, pelágico-oceánicos) y la variabilidad oceanográfica (cambios estacionales marcados en la productividad, la TSM, la termoclina, la haloclina y la picnoclina) (Lara-Lara et al., 2008;Obeso et al., 2002), parecen fundamentales en la modulación de la presencia o ausencia de diversas especies de este grupo en la BLP Pardo et al., 2013;. ...
... La variación en la dominancia de las especies de misticetos relacionada con la temporalidad anual, parece ser independiente del esfuerzo de observación, ya que la falta de muestreo estandarizado aplica a todas las especies (figura 13) y coincide con lo documentado previamente para la zona, en donde tanto los rorcuales tropicales como las ballenas azules y los rorcuales comunes se alternaron como la especie más común Pardo et al., 2013). No obstante, lo anterior, el aumento en los registros de ballena jorobada a partir del 2010 indica que su recurrencia en los últimos años podría estar relacionada con la variabilidad climática de gran escala tal y como se ha reportado para otras especies (Salvadeo et al., 2010(Salvadeo et al., , 2011. ...
En el Golfo de California, la Bahía de La Paz representa un importante capital natural. Su situación geográfica, la protección que ofrece contra fenómenos meteorológicos, la abundancia de sus recursos naturales y su innegable belleza, propiciaron que en este lugar se desarrollara la ciudad de La Paz hace más de 400 años. Desde entonces, sus aguas, costas e islas han sido fuente de sustento para sus habitantes. Esta obra comprende 26 capítulos agrupados en tres secciones, Oceanografía y Climatología, Zona Costera y Zona Marina. La Primera sección incluye trabajos sobre la variación batimétrica de la ensenada de La Paz, la distribución de nutrientes y clorofila en el estero El Conchalito, y las condiciones oceanográficas de la Bahía de La Paz durante El Niño. La sección de Zona Costera, presenta trabajos de aspectos biológicos, como el del camarón de salmuera en la salina de Pichilingue; de aspectos ecológicos como la florística del medio terrestre, los anfibios y reptiles terrestres de la bahía e islas; y de aspectos sociales y económicos como la caracterización antropogénica en el complejo insular de Espíritu Santo, los requerimientos de energía de la ciudad de La Paz, la vulnerabilidad y adaptación al cambio climático del turismo y la pesca, y la maricultura en la bahía. La sección de Zona Marina es la más grande y comprende trabajos de diferentes taxa enfocados a aspectos biológicos, ecológicos, de aprovechamiento y conservación. Los cuales incluyen toda la Bahía de La Paz, sobre corales escleractinios, copépodos, esponjas, tortugas y mamíferos marinos. Estudios en localidades específicas como el de comunidades ícticas en manglares, equinodermos en aguas someras de las islas, y moluscos de la facie rocosa de la isla Espíritu Santo. Trabajos sobre temas diversos como la reproducción de bivalvos, de los afloramientos de dinoflagelados, de los patrones espaciales de la biodiversidad animal marina en la bahía, y de varamientos de mamíferos marinos. Finalmente, dos estudios sobre taxonomía, conservación y aprovechamiento, uno sobre peces, y otro sobre tiburones y rayas.
