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Cabo Pulmo National Park (CPNP), within the East Cape of Baja California Sur, Mexico, is the location of a highly productive rocky reef ecosystem that was likely attractive to people throughout the Holocene. AMS radiocarbon dates from sites along the coast and faunal data from two excavated sites, D20 and D27, indicate people were present in the region by at least 7120–6755 cal b.p. (D34), but evidence of persistent occupation and possibly higher population densities postdates 2110–1945 cal b.p. (D27, Unit 1). The most prominent sites with intact stratified archaeological deposits appear to be focused adjacent to prominent rocky points, where assemblages include a variety of marine mollusks, fish, birds, terrestrial and marine mammals, and sea turtle remains. At both D20 and D27, there is evidence people targeted small fishes including sardines, likely with nets. This study highlights the strong archaeological potential in CPNP to address questions about human coastal adaptations and population history during the Holocene, emphasizing the importance of protecting cultural resources in an area at risk from growing tourism and residential development. [ABSTRACT FROM AUTHOR]

Copyright of Economía, Sociedad y Territorio is the property of El Colegio Mexiquense and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Research on the feeding habits of batoids provides information of intra and interspecific interactions of this taxon in marine ecosystems. We analyzed 832 stomachs of nine ray species collected from the artisanal fishery on the Northwest coast of Baja California Sur (NBCS). We identified 79 prey items assembled in five trophic groups (crustaceans, fish, mollusks, polychaetes, and sipunculidae). Results indicated that the red crab Pleuroncodes planipes was the most important prey in the diet of the seven batoid species. A low dietary similarity of the rays was observed, which evidenced different feeding strategies. In this regard, we identified four well‐separated trophic guilds. Each guild was characterized by the consumption of specific prey: (1) Hypanus dipterurus and Narcine entemedor that fed mostly on polychaetes; (2) Rostroraja velezi and Gymnura marmorata fed mostly on fishes (Clupeidae and Batrachoididae); (3) Hypanus longus, Myliobatis californica, and Platyrhinoidis triseriata fed on crustaceans (Munnidae) and Sipunculus worms; and (4) Pseudobatos productus and Zapteryx exasperata fed on crustaceans (Portunidae) and fishes (Synodontidae and Batrachoididae). We concluded that batoids off the NBCS show prey sharing between the different species. [ABSTRACT FROM AUTHOR]

The aetiocetids are a well-known extinct taxon of Oligocene toothed mysticetes in the North Pacific. They display a high degree of diversity contrasting with that of other tooth-bearing mysticetes such as mammalodontids, llanocetids and Coronodon spp. The disparate developmental patterns (heterochrony) and origin of the first kelp forests in the North Pacific during the Eocene–Oligocene transition might explain such diversity. Aetiocetidae have been the focus of debate regarding the origin of baleen and filter-feeding in Mysticeti. The current interpretation of aetiocetid feeding strategies is based on the presence of teeth, unfused mandibular symphysis and lateral palatal foramina. However, our understating of their feeding apparatus function is limited, leaving associated structures like the zygomatic arch unnoticed. The present study describes a new fossil of a small-sized mysticete (∼3 m long), Kaaucetus thesaurus gen. et sp. nov., which belongs to Aetiocetidae. The protruded squamosal prominence and distinctive zygomatic process present in this new fossil highlight disparity in feeding morphology amongst aetiocetids. Moreover, the zygomatic arch complex and masticatory muscle system reconstruction are crucial to interpreting the likely capability of mastication (shearing motion) in aetiocetids and other toothed mysticetes. Lastly, the record of several aetiocetid genera in Mexico extends the geographical range of the group into the subtropical region. [ABSTRACT FROM AUTHOR]

In diatoms the use of molecular tools to corroborate traditional (morphological) identification offers a new perspective in the field of biogeography. This manuscript reports the first record of the raphid pennate diatom Nitzschia volvendirostrata along the coast of Mexico, which in turn represents an expansion of the geographic range along the American continent. The cells were isolated from benthic samples taken from Balandra lagoon, La Paz, Baja California Sur, Mexico and cultured as a monoclonal culture. Morphology and morphometry of the diatom obtained from light and electron microscopy reveal that they correspond to the original description of N. volvendirostrata and also its chloroplast sequences, rbcL and psbC, showed 98.7 to 100 % similarity and a close phylogenetic relationship with N. volvendirostrata. The reported places for this taxon show that it has a tropical-temperate biogeographical affinity. [ABSTRACT FROM AUTHOR]

We investigate whether age profiles of ethnobiological knowledge development are consistent with predictions derived from life history theory about the timing of productivity and reproduction. Life history models predict complementary knowledge profiles developing across the lifespan for women and men as they experience changes in embodied capital and the needs of dependent offspring. We evaluate these predictions using an ethnobiological knowledge assessment tool developed for an off-grid pastoralist population known as Choyeros, from Baja California Sur, Mexico. Our results indicate that while individuals acquire knowledge of most dangerous items and edible resources by early adulthood, knowledge of plants and animals relevant to the age and sex divided labor domains and ecologies (e.g., women's house gardens, men's herding activities in the wilderness) continues to develop into middle adulthood but to different degrees and at different rates for men and women. As the demands of offspring on parents accumulate with age, reproductive-aged adults continue to develop their knowledge to meet their children's needs. After controlling for vision, our analysis indicates that many post-reproductive adults show the greatest ethnobiological knowledge. These findings extend our understanding of the evolved human life history by illustrating how changes in embodied capital and the needs of dependent offspring predict the development of men's and women's ethnobiological knowledge across the lifespan. [ABSTRACT FROM AUTHOR]

This article argues that the recent emphasis on quantitative methods should also include the application of rigorous science-based methodologies for the study of sound and acoustics among past communities. The benefits of including methods developed in acoustical physics have been shown with the analysis of the rock art landscape in the Cañón de Santa Teresa gorge in Baja California Sur (Mexico), where the Great Mural rock art tradition was produced. Thanks to a thorough examination of a series of monaural and binaural acoustic parameters, we have been able to conclude that the artists selected the best sonic landscapes in which to create their rock art, both paintings and carvings, especially the latter. We have also been able to demonstrate that the sector of the canyon with a special concentration of two profusely painted caves, Cueva Pintada and Las Flechas, is precisely that with the most favorable acoustic conditions in the whole tested area. • Intangible aspects of culture such as sound should be part of the new focus on quantitative methods in archaeology. • A more sophisticated exploration of acoustic parameters is possible than just focusing on echoes, reverberation and resonance. • Monaural acoustic parameters: T20, G, C50 and C80. Binaural acoustic parameters: Lj and Jlf. • The Great Mural rock art producers selected the best sonic environments for rock art. • Discussion about the validity of the ethnohistorical sources in order to understand the Great Mural rock art tradition. [ABSTRACT FROM AUTHOR]

Small stands of mangrove trees are difficult to detect and monitor using satellite remote sensing because the width of the narrow strips of vegetation are typically much smaller than the spatial resolution of the imagery. Every mangrove pixel also contains water and bare soil reflectance. Linear spectral unmixing, which estimates the fractional presence of specific land cover types per pixel, was performed on Landsat 8 imagery to detect mangroves on the eastern shoreline of the Bay of La Paz on the Baja California Peninsula of Mexico. Low-altitude aerial imagery collected from a DJI Mavic Pro drone was used as ground-reference data in the accuracy assessment. Continuous fractional presence of mangroves was detected with 80% accuracy and 85% of mangrove area was found. Future work will use linear spectral unmixing to systematically monitor mangrove extent and health in the region relative to expected growth in tourism development. [ABSTRACT FROM AUTHOR]

Based on hydrographic data from two cruises (June 2010 and May 2012) off Baja California Sur, Mexico, historical in situ measurements from the World Ocean Database 2018, California Cooperative Oceanic Fisheries Investigations, and Investigaciones Mexicanas de la Corriente de California cruise programs, as well as satellite images and data from the Global Reanalysis, this study describes the California Current System off Baja California Sur. The California Current System is characterized by the interaction of four near-surface currents. Far from the coast, the California Current flows within the North Pacific Subtropical Gyre but does not reach the Pacific Tropical-Subtropical Convergence off Mexico. From December to June, an equatorward flow known as the Tropical Branch of California Current emerges along the coast. This flow intensifies from March to June and is closely related to the mass flux induced by coastal upwelling. In July, a new branch of the Tropical Branch of the California Current turns poleward along the Baja California Sur coast. This flow is often referred to as the California Surface Countercurrent because it flows in the opposite direction to the California Current. Additionally, the California Undercurrent is detected, influencing the water column from 100 to 900 m, with a maximum poleward flow between 200 m and 300 m, decreasing toward the surface. The California Undercurrent persists throughout the year over the continental slope, displaying a significant semiannual component around the Gulf of California entrance. The California Current System off Baja California Sur plays a crucial role in the formation of Transitional Waters within the Pacific Tropical-Subtropical Convergence off Mexico. The importance of equatorward flows by the Tropical Branch of California Current in ventilating the Oxygen Minimum Zone waters in the Central Pacific off Mexico is emphasized. [ABSTRACT FROM AUTHOR]

Outcrops of Upper Triassic carbonates of shallow-marine character are rare in Mexico. Another locality, next to the Antimonio depositional system (ADS) in Sonora, is found on the Vizcaíno terrane (Baja California Sur), near the village of San Hipólito. The outcropping formation is named after the nearby village and represents an arc-ophiolite assemblage. The formation comprises a limestone breccia, which includes re-worked Upper Norian shallow-water limestone. In addition, questionable lowermost Rhaetian radiolarians have been found in some clasts of the breccia. Accordingly, the breccia member possibly deposited during the uppermost Norian–lowermost Rhaetian. Based on their preservation, 43 clasts representative of the main lithologies have been sampled along a 550-m-long outcrop surface. Some authors proposed the Vizcaíno to have been in close relation to the ADS in north-western Sonora. It has been proposed that the Antimonio served as the source of the limestone clasts contained within the San Hipólito Formation. Petrographic analysis and micropaleontologic evidences, however, indicate a more distal relationship between the two systems. Furthermore, the microfacies proposed by the hierarchical clustering include some rather poorly constraint facies. This could be explained by the facts that (a) the samples have derived from clasts that not necessarily represent a stratigraphic succession and (b) multiple systems could have contributed to the assemblage. [ABSTRACT FROM AUTHOR]

Temporal variability driven by environmental shifts, biological processes, and socioeconomic fluctuations is inherent in natural resource-based sectors, including fisheries. In navigating these changes as opportunities for transformation, individual decisions play a key role. Understanding individual adaptive capacity, i.e., the ability to cope under changing or novel circumstances, and considering how this capacity is affected by diverse individuals' interactions with formal fisheries policy may allow a better understanding of adaptive capacity in a rapidly changing world. In Loreto Bay National Park, Baja California Sur, Mexico, the Mexican chocolate clam is an important source of food and livelihoods and is harvested by a diverse group of fishers. Understanding the diversity of fishers, their decision-making processes, and their adaptive strategies is essential for both anticipating fishery outcomes and predicting the capacity of different types of fishers to adapt to environmental and economic change. We used semistructured interviews with clam harvesters to ask: (1) What types of fishers exist within the chocolate clam fishery? (2) How do they differ in their adaptive strategies? and (3) What are the implications of diverse fisher types on individual adaptive capacity? We find that fishers of chocolate clams in this region operate within both the formal and informal sectors, have varied fishing strategies, and can be characterized into four discrete types. We also find that heterogeneity among fishers affects their individual capacities to adapt to changing conditions and disturbances, and fisheries policy constrains fishers' access to options by limiting secure access to fishing rights. Maintaining a diverse suite of adaptive strategies is essential for individuals to cope in the face of future disturbance and change. Likewise, maintaining heterogeneity in the fishery, by ensuring that multiple fisher types are equipped to adapt to future change, will strengthen adaptive capacity within the fishery and community. [ABSTRACT FROM AUTHOR]

Introduction: The study of age and growth in fishes is a basic prerequiste to generate information on longevity, growth rates, population structure, among other attributes, all of them for the application of policies focused on the population management and conservation. We evaluated these attributes in the endangered Baja California killifish (Fundulus lima) that inhabits the oases of Baja California Sur, Mexico, with the perspective of generating base information for the conservation of this endemic fish. Objective: To determine the age, somatic growth and population structure of F. lima in one of the most important hydrological basins of its distribution range. Methods: From October 2002 to July 2004 we sampled for F. lima in 3 sites of La Purisima river by using passive and active collection methods. Individuals were measured and weighed in the field, where subsamples were selected for analysis of age based on scales. All of the individuals were released alive to its original sites of capture. We assessed the age, length-weight and length-length relationships and population structure on the basis of 802 individuals examined by non-invasive techniques. Results: The somatic growth of F. lima was of positive allometric type (b > 3.0) in all the populations studied, with values of "b" ranging from 3.126 (Ojo de Agua) to 3.420 (El Pilón). Three age class (0, 1 and 2 years old) were recognized, of which the age 1 year was the most frequent (49 %). The polimodal method based on length-frequency data also identified three age classes. Back-calculated total lengths at previous ages based in increments of growth in scales were 38.61 and 68.81 mm for individuals of 1 and 2 years, respectively. Conclusions: Three age classes (0, 1 and 2 years old) were determined for the populations of F. lima in La Purisima river, based on the interpretation of annual growth rings in scales and in the modal distribution of observed length frequencies. All the populations examined showed a positive allometric growth (b > 3.0). [ABSTRACT FROM AUTHOR]

Length-weight relationships (LWRs) were estimated for Pacific blue marlin (Makaira nigricans), striped marlin (Kajikia audax), sailfish (Istiophorus platypterus), dolphinfish (Coryphaena hippurus) and yellowfin tuna (Thunnus albacares). These five fish species are key top predators of the pelagic ecosystem and are economically important resources in the sport fishing of Baja California Sur, Mexico. Overall, 53,359 length and weight records were analyzed for the period 1990-2015. LWRs were significant (P < 0.05), with b-values ranging from 2.52 to 3.13. [ABSTRACT FROM AUTHOR]

Abstract: This article utilizes theories of value and space, along with Harvey's notion of “accumulation by dispossession,” to critically investigate the histories and social effects of the commodification of place on the East Cape of Baja California Sur, Mexico. The article defines value as the product of specific social relations and examines how places are created, valued, commodified, and co‐opted in the development process. The actual process of co‐optation, however, is highly contingent on the development of infrastructure, particularly roads, which play a vital yet ambivalent role in shaping how different people not only access but also value the East Cape. [ABSTRACT FROM AUTHOR]

In the State of Baja California Sur, Mexico, 25 species in eight genera of the family Aphelinidae were collected. A list of the recently known species of Aphelinidae, including host species and distribution, is given. A new species, Coccobius pedicellatus Myartseva, is described. [ABSTRACT FROM AUTHOR]

We present data on presence and abundance, and nesting activity of the exotic monk parakeet (Myiopsitta monachus) in the southern portion of the Baja California peninsula. The monk parakeet was recorded for the first time in November 2012 at the town of Chametla, 7 km North of La Paz city and since then the monk parakeet has increased its numbers. We recorded nesting activity between May-August 2013 and May-August 2014. Nests were built on Mexican fan (Washingtonia robusta, 75%) and coconut (Cocos nucífera, 25%) palms. Monk parakeets were observed feeding on fruits of date palm (Phoenix dactylifera), mesquite (Prosopis sp.), tamarin (Tamarindus indica), guamuchil (Pithecellobium dulce) and pearlberry (Vallesia glabra), and remains of human waste foods. Finally, we discuss the potential implications of the establishment of this exotic species in the region. [ABSTRACT FROM AUTHOR]

Two new species of Cryptocephalus Geoffroy, 1762 are described from the Baja California peninsula, Mexico: C. drewi sp. nov., and C. incognitus sp. nov., with illustrations of the male genitalia presented for the former. Specimens previously reported as C. sanguinicollis nigerrimus Crotch, 1874 from the Baja California peninsula were determined to represent C. drewi, while specimens previously reported as C. vapidus White, 1968 were identified as C. californicus Clavareau, 1913. As a result, C. sanguinicollis nigerrimus and C. vapidus are removed from the list of chrysomelid species believed to occur in the Baja California peninsula. A non-type male specimen of C. californicus is described, and differences between the male and female are provided. Color habitus photographs and information on distribution are provided for all three species. [ABSTRACT FROM AUTHOR]

Copyright of Revista de Historia is the property of Universidad de Costa Rica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Mexicana de Biodiversidad is the property of Universidad Nacional Autonoma de Mexico, Instituto de Biologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract: In arid climates, inputs of nitrogen and phosphorus in coastal waters are mainly driven by groundwater discharge, and runoff from oases near the coast. Each nutrient may increase from human activity and be a source of environmental pollution of coastal zones. We report on nutrient variability and content at five oases in Baja California Sur, their watercourses, and discharge sites to the sea during a 4 year period (2004–2007). Measurements were carried out of temperature, salinity, dissolved oxygen, nitrates, nitrites, ammonium, orthophosphates, and silicates along the oasis watercourses and adjacent coasts. Higher content of nitrogen and phosphorus was found at sites where agriculture and high populations were present. Differences on geographic localization, and rainfall rates were not an important factor on nutrient variability. Lagoons and estuaries as part of the end of the watercourses were important because these zones reduce nitrogen and phosphorus by biological activity and sediment retention, so that water quality of adjacent coast is not disturbed. The Oasis San José is affected by sewage input from a population (77 000 inhabitants) and this water body seems to be near its limit of assimilative capacity to these nutrients. [Copyright &y& Elsevier]

Mangroves constitute highly productive ecosystems that export organic material to surrounding areas. They reach their northernmost distribution on the American Pacific coast in arid northwestern Mexico where they grow under sub-optimal conditions. Nevertheless, they maintain high litterfall rates with important ecological and economical implications. These mangroves are threatened by the region's accelerated development and population growth. In order to explore and describe large-scale patterns in the production of organic material and to assess their importance in the productivity of coastal ecosystems, we performed a meta-analysis of studies that measured mangrove litterfall in northwestern Mexico. We found that litterfall is strongly associated with latitude, and that evaporation was negatively correlated with it. Additionally, we found high correlation between the presence of Rhizophora mangle and productivity, while the presence of Laguncularia racemosa, showed a less pronounced trend. Despite the harsh conditions, mangroves produce high amounts of organic matter, which is perhaps the most important service of mangroves in these coasts. Their capacity to produce organic matter contrasts with that of their surrounding ecosystems. Substantial reductions in their surface will have consequences for the exchange of energy at the land-sea transition, which will be detrimental for biological communities and human populations. [ABSTRACT FROM AUTHOR]

To evaluate the effects of desert scrub habitat fragmentation on resident and migrant populations of Red-tailed Hawk and American Kestrel, we conducted monthly raptor road surveys during two years, 2008 and 2009, in natural desert scrub areas and in fragmented areas of Baja California Sur, México. We recorded 1,806 records of the two raptor species. The most common was the American Kestrel with 1,164 (64.4%) records (51% found in fragmented area, and 49% in natural area). The Redtailed Hawk accounted for 642 records (35.6%) (70% in fragmented areas, and 30% in natural areas). The relative abundance and density of Red-tailed Hawk in the spring and summer were similar between areas, but in the fall and winter the abundances and densities were much higher in fragmented areas. The abundance of American Kestrel was similar between areas in all seasons. Density was similar between areas in spring, summer and winter but it was higher in fragmented areas in the fall. The desert scrub of Baja California Sur and fragmented areas inside a cultivated agricultural matrix is an important habitat for migrant populations of both raptor species as indicated by the results of the fall and winter seasons. We discuss on the raptor species tolerance to habitat changes (threshold concept) as a function of their body size and habitat specialization (for nesting and foraging activities) and on the effects of fragmentation of desert scrub habitats on the abundance and density of the Red-tailed Hawk and American Kestrel in southern Baja California peninsula. [ABSTRACT FROM AUTHOR]

Copyright of Papeles de Población is the property of Universidad Autonoma del Estado de Mexico and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Recreational fishing is a vital component of the tourism economy in Baja California Sur (BCS), Mexico, although several artisanal and industrial fisheries continue to operate in the region. The commercial long-liner fleet in particular is widely held to be responsible both for diminishing shark populations and declines in billfish through bycatch. Using available fisheries and ecosystem data, we develop an Ecopath with Ecosim (EwE) model to represent current ecosystem and fishing dynamics in BCS and explore the ecological and economic effects of specific fisheries policy measures. Results suggest that currently mandated bycatch limits for the longlining fleet will have little effect on marlin abundance in the area. In an overfished ecosystem, decreasing fishing effort can result in higher overall catches through population rebuilding. While perhaps ecologically justified, increases in the abundance of sharks, a top predator, can have negative effects on other valued species in the ecosystem. The effects of these trophic dynamics must not be overlooked, as they can negate or even reverse desired outcomes from fisheries management. [Copyright &y& Elsevier]

Fundulus lima inhabits river drainage systems and is threatened after the introduction of cichlids in the area. To support conservation programs, the spatial and temporal variation of the diet composition of this endangered killifish, was determined in two oasis systems of Baja California Sur, Mexico (San ignacio and La Purisima river drainages), during rainy and dry seasons. F. lima was captured by using passive and active capture techniques. A total of 192 stomach contents of F. lima was analyzed. The contribution of each prey item in the diet composition was quantified by means of the indices of occurrence frequency (% OF), numerical (%N) and volume (%V) percentages. The relative importance of each prey item was determined according to the percentage of the Relative importance index (%RII). The similarity of the diet was calculated between hydrological basins (populations combined by basin), seasons (rainy versus dry months), sexes and size classes, by using Schoener's resource overlap index. We used two ecological indices to determine the type of feeding strategy exhibited by the fish: (1) niche breadth of Levins and (2) proportional similarity of Feisinger. Sand was the most abundant item in the stomach content of killifishes from both drainages (39% and 47%, respectively). Diet composition was similar for both drainages (74%) as well as among their respective size classes; however, it was different between sexes. in both drainages, F. lima predated mainly on diatom algae, dipterous and trichopteran larvae, and fish scales during the dry season; while it preferred dipterous larvae, filamentous algae and ostracods in the rainy season. A feeding strategy of opportunist type was exhibited by F. lima during the rainy season, changing to specialist type during the dry season. This information will be the basis for future investigations related to the conservation of this endangered species and its habitat. [ABSTRACT FROM AUTHOR]

Abstract: Environmental pollution due to heavy metals is having an increased impact on marine wildlife accentuated by anthropogenic changes in the planet including overfishing, agricultural runoff and marine emerging infectious diseases. Sea turtles are considered sentinels of ecological health in marine ecosystems. The objective of this study was to determine baseline concentrations of zinc, cadmium, copper, nickel, selenium, manganese, mercury and lead in blood of 22 clinically healthy, loggerhead turtles (Caretta caretta), captured for several reasons in Puerto López Mateos, Baja California Sur, Mexico. Zinc was the most prevalent metal in blood (41.89μgg−1), followed by Selenium (10.92μgg−1). The mean concentration of toxic metal Cadmium was 6.12μgg−1 and 1.01μgg−1 respectively. Mean concentrations of metals followed this pattern: Zn>Se>Ni>Cu>Mn>Cd>Pb and Hg. We can conclude that blood is an excellent tissue to measure in relatively non-invasive way baseline values of heavy metals in Caretta caretta. [Copyright &y& Elsevier]

The fish assemblage in a coastal lagoon with mangroves known as "Rancho Bueno" was determined and associated with environmental parameters. We used an experimental otter trawl net to catch the fish, and 62 fish species were identified from 48 genera and 30 families. The most abundant species were: Etropus crossotus, Eucinostomus gracilis, Paralabrax maculatofasciatus, Sphoeroides annulatus, and Eucinostomus dowii. The water temperature changed seasonally, being warm from July through December and cold from January through June. We found more fish species during the warm season than during the cold season. The southern area of the coastal lagoon had the highest diversity and species richness. The small size of the fishes registered confirms the ecological role of coastal lagoons as nursery areas that offer protection and feeding to commercially important fish near Bahía Magdalena, Mexico. [ABSTRACT FROM AUTHOR]

The clam Megapitaria squalida is a fishing resource with increasing importance in Northwestern Mexico. Nevertheless, this fishery has shown important variations that could be related to environmental factors. To assess this, monthly landings of M. squalida were analyzed during 2002-2005 for Bahía de La Paz, B.C.S., and were related with monthly time series of sea surface temperature, derived from MODIS-Aqua Sensor. The results showed a positive and significant relationship between sea surface temperature and clam landings. The likely impact of anomalous conditions of sea temperature on this resource is discussed. Rev. Biol. Trop. 59 (1): 151-157. Epub 2011 March 01. [ABSTRACT FROM AUTHOR]

We identified and quantified organochlorine (OC) pesticide residues in the plasma of 28 osprey ( Pandion haliaetus) nestlings from a dense population in Laguna San Ignacio, a pristine area of Baja California Sur, Mexico, during the 2001 breeding season. Sixteen OC pesticides were identified and quantified. α-, β-, δ- and γ-hexachlorocyclohexane, heptaclor, heptachlor epoxide, endosulfan I and II, endosulfan-sulfate, p,p′-DDE, p,p′-DDD, aldrin, dieldrin, endrin, endrin aldehyde, and endrin ketone were the OCs found in the plasma of nestlings, ranging from 0.002 to 6.856 pg/μl (parts per billion). No differences were found in the concentration of pesticides between genders ( P > 0.05). In our work, the concentrations detected in the plasma were lower than those reported to be a threat for the species and that affect the survival and reproduction of birds. The presence of OC pesticides in the remote Laguna San Ignacio osprey population is an indication of the ubiquitous nature of these contaminants. OCs are apparently able to travel long distances from their source to the study area. A significant relationship between hemoglobin and mean corpuscular hemoglobin concentrations and OC concentrations were found suggesting that a potential effect on the health of chicks may exist in this osprey population caused by the OC, e.g. anemia. The total proteins were positively correlated with α-BHC, endosulfan I, and p,p′-DDD. It has been suggested that OC also affects competitive interactions and population status over the long term in vertebrate species, and our results could be used as reference information for comparison with other more exposed osprey populations. [ABSTRACT FROM AUTHOR]

Gracilaria vermiculophylla, from Baja California Sur, Mexico, was studied in order to determine the seasonal variation of yield and quality of native and alkaline agar during 2007-2008. The highest alkaline agar yield was obtained in summer (17%) and the highest gel strength in spring (1,132 g cm). The highest melting temperature was 98°C (winter). The highest gelling temperature was 68°C (summer). The values obtained are within the range of the most important Gracilaria species harvested worldwide. During the agar extraction step, the best results were obtained after 30 min of alkali treatment with sodium hydroxide (7%), after which the quality decreased significantly. We produced Colagar from G. vermiculophylla which consists of the seaweeds treated with sodium hydroxide and dried. The yield and quality of the agar obtained from the Colagar shows stability in both yield and quality during 1 year of storage, suggesting that alkali treatment is a good method of avoiding agar hydrolysis during storage. [ABSTRACT FROM AUTHOR]

This paper analyzes the characteristics of migration process in Baja California Sur, on the Pacific Ocean coast of northwest Mexico, where immigration has impacted the local economy through the development of tourism and intensive agriculture that target foreign markets. This has encouraged an annual rate of population growth of 10% during the last decade, feeding into employment in both formal and informal sectors. Referring to the cases of women who develop beach vending activities and agricultural workers, this paper seeks to contribute to the understanding of how migration and the informal labor market intertwine [ABSTRACT FROM AUTHOR]

Multiple populations of Hadrurus pinteri from Baja California Sur, Mexico have been examined. It is demonstrated that the southern populations of this species have a larger number of accessory trichobothria (neobothriotaxy) than the northern populations, numbers exceeding the maximum currently recorded for the genus. Examination of carapace and chela coloration and its patterns show a close affinity between H. pinteri and the dark phase of H. concolorous. A new morphometric ratio of the carapace is defined that distinguishes Hadrurus from Hoff mannihadrurus, further supporting the monophyly of the latter genus. [ABSTRACT FROM AUTHOR]

Copyright of Revista Mexicana de Biodiversidad is the property of Universidad Nacional Autonoma de Mexico, Instituto de Biologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The Gulf of California nacre shell Pteria sterna is an important marine resource in Mexico, and the main species for "half" and round pearl production in the American continent. Wild spat can only be extracted legally for research or culture activities. This study calculates growth and mortality parameters for wild stocks in the eastern coast of Southern Baja California. Height's data (353 dorso-ventral measurements) were taken from 1997 to 1999 at Santa Rosalía, Mulegé and Loreto Bay coast. The maximum length was estimated at 130.35 mm (124.22-136.48 mm, p>0.95). The length frequency data were set in a "virtual year". Seasonal von Bertalanffy growth parameters were calculated in the ELEFAN I routine, the values are: L∞ = 156.02 mm, k = 0.48 year-1, t0 = -0.216 years, C = 0.43, WP = 0.73. and ts = 0.5. The growth performance index was Φ' = 4.068. The total mortality was calculated from length-converted catch curve Z = 3.34 year-1. The length-weight relationship was fixed for the equation W = 0.000756 * L(i) 2.7075 (r² = 0.90, n = 233). The growth parameters values in experimental repopulation conditions are quite different, in contrast with the growth estimated in wild stocks oysters. The value of total mortality is similar to the estimations for Pinctada fucata populations from the Red Sea and P. radiata from the Mediterranean Sea. [ABSTRACT FROM AUTHOR]

Fishers often rely on their social capital to cope with resource fluctuations by sharing information on the abundance and location of fish. Drawing on research in seven coastal fishing communities in Loreto, Baja California Sur, Mexico, we examine the effect of resource scarcity on the bonding, bridging, and linking social-capital patterns of fishers' information-sharing networks. We found that: (1) fishers' information sharing is activated in response to varying ecological conditions; (2) resource scarcity is an ambiguous indicator of the extent to which fishers share information on the abundance and location of fish within and between communities; (3) information sharing is based on trust and occurs through kinship, friendship, and acquaintance social relations; (4) friendship ties play a key and flexible role in fishers' social networks within and between communities; (5) overall, the composition of fishers' social networks follows a friendship>kinship>acquaintance order of importance; and (6) the function of social ties, internal conflict, and settlement histories moderate the effects of resource scarcity on fishers' social capital. We conclude by arguing that the livelihoods of fishers from Loreto have adaptive capacity for dealing with fish fluctuations but little or no proactive resilience to address resource-management issues. [ABSTRACT FROM AUTHOR]

Copyright of Revista Mexicana de Economía Agrícola y de los Recursos Naturales is the property of Universidad Autonoma Chapingo and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The susceptibility of the pepper weevil (Anthonomus eugenii), collected from Baja California Sur, Mexico, to seven insecticides was determined. A contact, residual exposition method was used to obtain the lethal concentrations fifty (LC50) and the diagnostic concentration (LC95) of organophosphates (OF), carbamates (CA), pyrethroids (PIR), and organochlorine (OC) insecticides used to control pepper weevils from two agricultural areas (Los Planes and Todos Santos) in Southern Baja California Peninsula, as well as on a pepper weevil population not exposed to insecticides (PWIF) for two years. The highest LC50's were obtained for methomyl (CA) and oxamyl (CA), followed by methamidophos (OF), endosulfan (OC), cyfluthrin (PIR) and azinphos-methyl (OF). The lowest LC50's were observed for carbaryl (CA). The field population from Todos Santos showed lower susceptibility than the population from Los Planes to insecticides as methomyl, oxamyl, and carbaryl, while with methamidophos, azinphos-methyl, and cyfluthrin, the LC50 showed higher values. The PWIF population presented the lowest LC50 values of all three populations tested. However, in most cases, the difference was not significant in relation to the two field populations, thus the PWIF population needs to be kept free of insecticides for longer periods to establish a susceptibility baseline for Anthonomus eugenii. [ABSTRACT FROM AUTHOR]

Taxonomic composition and zoogeographic relations of demersal in the western coast of Baja California Sur, Mexico. The composition of demersal fish along the western coast of the State of Baja California Sur, México, including the limit of the northern distribution of the ichthyofauna of the eastern tropical Pacific, is presented. The survey was carried out on four oceanographic cruises between autumn 2004 and March 2006. Of 220 species in 132 genera and 73 families, 26.3% are species of wide distribution from San Diego County, USA to Panama and 21.7% are species restricted to the eastern tropical Pacific. Six species are new findings for the area or range expansions. The families with the most species are Paralichthyidae and Scorpaenidae, each with 16 species. The most frequent genus was Sebastes, with nine species. We present a table with common Spanish names, size range and status of each species inside the community. [ABSTRACT FROM AUTHOR]

Portulaca californica is one of five species in the genus distributed on the Baja California peninsula and is endemic to the state of baja california sur. Little is known about its distribution and biology. We studied the species in the field and herbarium to improve upon the limited knowledge. It is a perennial plant with stems prostrate to decumbent, leaves imbricate in young individuals and at branch tips in mature plants, flowers magenta, the lid of the capsule campanulate, and seeds shiny grey. The species is distributed along both coasts of the southern part of the peninsula, where accelerated development for tourism is a threat to the survival of the species. [ABSTRACT FROM AUTHOR]

To test the hypothesis that spatial heterogeneity determines waterbird diversity in a coastal wetland, we compared waterbird density, diversity, and species composition among various habitats and landscapes units in Bahía Magdalena-Almejas, Baja California Sur, Mexico. Based on diversity patterns and bird distribution, we assessed the effect of coastal development on the waterbird community structure. To gather information on habitat features and waterbird populations we conducted waterbird censuses in 329 habitat segments along the internal coastline of the study area, from February 2002 to February 2003. We performed non-parametric analyses to test the null hypothesis of no diference on waterbird density, and diversity among landscape units and seasons. The species composition was evaluated using ordination techniques. Waterbird density was higher in winter and autumn in the three lagoons of the study area, particularly in the insular coast, sandy beach and dunes; it was higher in the few segments of antropic sustrate. Diversity was significantly higher in mangrove habitat along the peninsular coast, and in mangrove-dunes association on the insular coast. Although modification of coastal natural habitat and boat transit disturbance had no influence on waterbird density or diversity, the highest richness of waterbirds occurred in well preserved areas. Species composition analysis showed differences between Santo Domingo Channel and Magdalena Bay. Pelagic and mangrove habitat had a species composition difference higher than those associations in other habitats. Such differences in species assemblages by habitat and landscape units suggest that communities are structured according to the range of available natural resources in structurally complex habitats, and that dominant piscivorous waterbird species were favored in this community. [ABSTRACT FROM AUTHOR]

Los Cabos, Baja California Sur, is one of Mexico's most popular tourist destinations. With 25% of the state's population, it has one of the highest population growth rates in the country mostly due to large scale tourism development. Economic and population growth mean greater water consumption. The region's main water source is the San José aquifer is overexploited. Private desalinazation plants as well as wastewater reclamation plants are becoming important alternative technologies for water management at resort hotels. The projections for population growth and water consumption in the region are alarming. Clearly there is an urgent need to design renewable resources management strategies, diversify technological alternatives, and design public policies to face the challenges of the future. [ABSTRACT FROM AUTHOR]

In late autumn 2004 we studied the effect of water surface condition, wind speed, and tidal status on the hunting patterns (flapping, gliding, hovering) and hunting success of the osprey population at Magdalena Bay, Baja California Sur, Mexico. Through focal sightings we obtained the number of hunting dives, hunting length, and the proportion of hunting length invested in each pattern. Hunting success was 61%. Ospreys required an average of 2.4 dives to catch a prey. Hunting lasted 450 seconds on average, with about 50% of this time invested in flapping, 41% in gliding, and 7% in hovering. The average number of dives to catch a prey varied according to the different water surface conditions, wind speed, and tidal status. The probability of catching a prey decreased when wind speed increased and the condition of the water surface deteriorated; however, hunting length was similar in both cases. Ospreys at Magdalena Bay decrease the proportion of flapping and increase gliding when wind speed increases and the condition of the water surface changes from calm to choppy. The change from low to high tide favored an increase in the probability of catching a prey and in the number of dives, but hunting length was not affected. We compared our results with studies from other regions. [ABSTRACT FROM AUTHOR]

Abstract: A solid phase extraction and gas chromatography with negative chemical ionization mass spectrometry in scan mode (GC-NCI-MS) method was developed to identify and quantify for the first time low levels of organochlorine pesticides (OCs) in plasma samples of less than 100μl from wild birds. The method detection limits ranged from 0.012 to 0.102pg/μl and the method reporting limit from 0.036 to 0.307pg/μl for α, γ, β and δ-hexachlorocyclohexane (HCH), heptachlor, aldrin, heptachlor epoxide, endosulfan I, 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (p,p′-DDE), dieldrin, endrin, endosulfan-II, endrin-aldehyde and endosulfan-sulfate. Pesticide levels in small serum samples from individual Falco sparverius, Sturnella neglecta, Mimus polyglottos and Columbina passerina were quantified. Concentrations ranged from not detected (n/d) to 204.9pg/μl for some OC pesticides. All levels in the food web in and around cultivated areas showed the presence of pesticides notwithstanding the small areas for agriculture existing in the desert of Baja California peninsula. [Copyright &y& Elsevier]

The decomposition of leaf litter for five dominant plant species of a desert scrub in Baja California Sur, Mexico was investigated. We designed a factorial decomposition experiment using decomposition bags and the collected leaf-litter from Prosopis articulata, Jatropha cinerea, J. cuneata, Cyrtocarpa edulis, and Fouquieria diguetti. Factors, such as radiation exposure, rainfall, and the size of litter-consuming organisms were considered. The rates of litter decomposition were calculated for these plant species and the environmental conditions by using single exponential models. The initial concentration of nutrients (C, N, P, K, and Ca) and crude-fiber content of the leaf litter were determined. Our results show that the environmental heterogeneity generated by different conditions of radiation exposure and short-term rainfall patterns are the most relevant factors affecting decomposition processes in this Sonoran desert community. A species-specific pattern was observed in decay rates and mass-loss patterns. Decomposition rates varied from 0.0027 to 0.0201 depending on the species and exposure to different ecological conditions. The decay rates were higher under bare-soil conditions and during a wet year than under the shade provided by the canopy of nurse trees and during a dry year. The leaf litter of J. cuneata reincorporated to the soil more rapidly than that of P. articulata and C. edulis. Termites were the more important macroarthropods associated with litter decomposition, and their harvest distribution was independent of the resources distribution. The ecological significance of these results is discussed considering the extreme climatic conditions prevailing in this region. [ABSTRACT FROM AUTHOR]

This article analyzes El Vizcaíno Bioreserve in terms of gender relations and their interconnections with its environmental reality. An attempt is made to contribute elements that could serve as inputs for implementing programs and actions might allow the region to become an area where development would not be at variance with resource conservation and where women would constitute the crux of an equitable and sustainable economic growth process. The article begins by explaining the conceptual and the methodological framework on which the analysis is based. Then, El Vizcaíno bioreserve, as a protected natural environment, is briefly introduced. Gender relations in the bioreserve's various microregions are analyzed as are their interconnections with the microregion's environmental dynamics. Finally, the study's conclusions are offered. [ABSTRACT FROM AUTHOR]

Groundwater quality in the Santo Domingo Irrigation District area in Baja California Sur, Mexico, indicates the presence of various salinization processes, (1) the geological matter of marine origin comprising the aquifer material suffers diagenetic effects due to its interaction with groundwater of low salinity, (2) the effects of intensive agriculture practices produce effluents that infiltrate to the saturated zone, and (3) the extraction of groundwater causes modifications in the natural flow system induces lateral flow of seawater from the coast line. However, groundwater management has been carried out with the belief that the latter is the main source of salinization. This has resulted in a policy of installing wells increasingly far from the coast, which is not solving the problem. Irrigation-return and seawater that remains in the geological units have been identified as major sources of salinization. Controls should be imposed when installing wells in contact with clayey units that form the base of the aquifer. Extracted groundwater consists of a mixture of (1) groundwater of relatively low salinity that circulates in the aquifer and (2) an extreme member with salinity different to seawater contained mainly in formations that have low permeability, which limits the aquifer underneath. The geochemistry of carbonates and cation-exchange reactions (both direct and reverse) control the concentration of Ca, Mg, Na, and HCO3, as well as pH values. The concentrations of dissolved trace elements (F, Li, Ba, Sr) suggest that the extreme saline member is different from the average seawater composition. A distinction between the salinization caused by farming practices and that blamed on seawater is defined by the use of NO3. [ABSTRACT FROM AUTHOR]

We studied the diet of the coyote (Canis latrans) in the Vizcaino desert, Baja California Sur, México. The studied was carried out in the summer and winter seasons of 1996 and 1997, respectively. We analized 302 feces and determined 8963 prey items, for 64 animal taxa and 10 of plants. Arthropods were the most frequent prey, representing 95% of identified items in the winter. Prey weight 0 to 20 g was the most consumed prey size category although ingested biomass was greater from the 1280 to 2560 g prey category. The B values indicate that the coyote in the Vizcaino desert showed a trend to be a relatively specialist predator on arthropods. [ABSTRACT FROM AUTHOR]

The distal end of a humerus from a pelican was found in upper Miocene marine strata in the lower part of the Trinidad Formation near Rancho La Trinidad in Baja California Sur, México. This bone represents the first bird fossil from the Trinidad Formation and the first Neogene record of Pelecanus from México. Not only is this one of the very few fossils of the family Pelecanidae from Neogene strata in North America, but it is also the first record of a pelican from Neogene marine rocks in western North America. • This work is the first Neogene record for the genus Pelecanus in Mexico. • This is the first record of fossil marine bird from the Trinidad Formation. • This is one of the few fossil records for Pelecanus in North America. • This is the first record for Pelecanus from Neogene marine rocks in western North America. [ABSTRACT FROM AUTHOR]

Total mercury concentrations ([THg]) in muscle were determined in commercial finfish and elasmobranchs from Baja California Sur (BCS), Mexico to evaluate dietary Hg exposure for BCS communities, including the relationship of trophic ecology, length and mass with [THg] that might drive future consumption advice (e.g., recommend limited consumption of large fish for some species). The [THg] ranged from 0.06 to 528.02 μg kg−1 ww in finfish and 17.68–848.26 μg kg−1 ww in elasmobranchs. Relative to the consumption threshold set for predatory fish in Mexico, all species had a concentration below 1000 μg kg−1 ww. As expected, 16 (4.02%) and 75 (18.84%) individual fish were above advisory thresholds of 500 and 200 μg kg−1 ww, respectively. The hazard quotients (HQs) in most species were significantly <1.0, only banded guitarfish showed a significant median HQ > 1.0. Thus, the relative level of risk of high Hg exposure is low for most species. • Dietary Hg exposure was assessed through fish consumption in a Mexican coastal community. • Fish muscle [THg] varies by length, weight and trophic ecology in most species. • In all species[THg] was below the threshold set for predatory fish in Mexico. • The hazard quotients (HQs) in most species were significantly <1. • The relative level of risk of Hg toxicity is low for most fish species. [ABSTRACT FROM AUTHOR]