Baja California Sur Research Articles

Social-ecological Resilience Modeling: Water Stress Effects in the Bighorn Sheep Management System in Baja California Sur, Mexico

Bighorn sheep (Ovis canadensis) management involves ecological and socioeconomic aspects, creating a social-ecological system (SES). Social-ecological thresholds can be identified in the system to assess its specific resilience in response to climate stressors. Thus, the aim of this study is to build a dynamic model to assess whether this system is resilient to a particular stressor (water stress). In this study, the SES is considered resilient if the bighorn population is sufficiently large to provide economic revenue to landowners and promote conservation action. We validate and formalize this model by conducting semistructured interviews to Bonfil ejido landowners located in Baja California Sur (BCS), Mexico, and to experts in the field of recreational hunting and wildlife management. To explore the changes in specific resilience in this SES, we conduct simulations to assess the impact of rainfall variability patterns on the system. Our results indicate that rainfall variations with respect to the historical record have the potential to disrupt both the species and the local economy and that the lack of adaptive capacity in both harvest and conservation strategies may affect the dynamics of the whole SES. Finally, this paper explores how adaptive wildlife conservation management strategies can enhance the resilience of both subsystems in this SES.

Participatory research to understand spatio-temporal dynamics of small-scale fleets: The C. bellicosus fishery in Magdalena Bay, Baja California Sur, Mexico

Small scale fishing is one of the main sources of income, food, and livelihoods for coastal communities. Despite this, it is an activity that faces challenges, among others the lack of scientific information about the state of the resources and the operation of fleets both necessary for management/conservation decisions. Magdalena Bay, a region recognized for supporting important fisheries, contributes more than 75% of the production of warrior swimming crab in Baja California Sur (BCS). Therefore, the present study intends to understand the spatio-temporal dynamics of the warrior swimming crab fleets from collaborative efforts with fishers in the generation and interpretation of information. Official catch landing reports database for the period 2001–2018 was used, spatio-temporal data of the fleets operations was generated through GPS data loggers (2015–2018), and the results were validated and complemented through surveys that incorporate local knowledge. The results include the analysis of catch per trip and fishing intensity, which identify more than 6800 fishing grounds and five main fishing areas Los Arenales, Estero Las Tijeras, Isla de Patos, and La Boya. The average indicators per daily operations determined that the best season for the fishing of warrior swimming crab is summer to autumn when 42.3 kg was captured, covering 43.9 km, and 33.6 L of fuel plus 8.9 h were invested. It was found that 51% of the fisher's fish exclusively warrior swimming crab, while the rest alternate their activities with others fisheries such as finfish, geoduck clam, and shrimp. Maps and economic indicators obtained are valuable inputs to reflect on best fishing practices and improvements in management measures in use, with the advantage that these results were obtained with the participation of users, in a transparent way, and consequently improves their use and acceptance.

Marine bacteria associated with shallow hydrothermal systems in the Gulf of California with the capacity to produce biofilm inhibiting compounds.

Shallow hydrothermal systems are extreme environments. The sediments and fluids emitted from the vents present unusual physical and chemical conditions compared to other marine areas, which promotes unique biodiversity that has been of great interest for biotechnology for some years. In this work, a bioprospective study was carried out to evaluate the capacity of bacteria associated with shallow hydrothermal vents to produce biofilm-inhibiting compounds. Degradation assays of N-acyl homoserine lactone (AHL) autoinducers (C6HSL) involved in the quorum sensing process were carried out on 161 strains of bacteria isolated from three shallow hydrothermal systems located in Baja California Sur (BCS), Mexico. The biosensor Chromobacterium violaceum CV026 was used. Twenty-three strains showed activity, and organic extracts were obtained with ethyl acetate. The potential of the extracts to inhibit the formation of biofilms was tested against two human pathogenic strains (Pseudomonas aeruginosa PAO1 and Aeromonas caviae ScH3), a shrimp pathogen (Vibrio parahaemolyticus M8), and two marine strains identified as producing biofilms on submerged surfaces (Virgibacillus sp C29 and Vibrio alginolyticus C96). The results showed that Vibrio alginolyticus and Brevibacillus thermoruber, as well as some thermotolerant strains (mostly Bacillus), produce compounds that inhibit bacterial biofilms (B. licheniformis, B. paralicheniformis, B. firmus, B. oceanizedimenis, B. aerius and B. sonorensis).

Caracterización socioeconómica de la pesca deportiva en tres localidades de Baja California Sur, México

La pesca deportiva es una actividad turística que genera una considerable derrama económica para el estado de Baja California Sur (BCS). En este sentido, es importante conocer las características de los pescadores recreacionales, para generar estrategias de manejo apropiadas a los contextos locales. Este estudio caracterizó la actividad y el perfil del pescador deportivo que visita BCS, además de identificar su percepción sobre la técnica de captura y liberación, la cual favorece la conservación de los recursos. Con un total de 922 encuestas en tres localidades, Cabo San Lucas, Los Barriles-Buenavista e Isla Cerralvo, se identificó que más del 80 % de los pescadores deportivos que acuden a BSC son de origen extranjero (principalmente de EUA), que el nivel de experiencia de pesca que predomina es el intermedio y que tienen una percepción favorable de la práctica de capturar y liberar; sin embargo, en éstas y en otras características (e.g. ingreso, edad, horas de traslado, entre otras) las proporciones entre las localidades son diferentes. Considerando la información de carácter socioeconómico, se caracterizaron dos tipos de pescador deportivo: el de ocasión y el exclusivo. Además, se identificó que el género femenino es un segmento de mercado poco atendido, el cual tiene potencial de crecimiento.

Using carbon and nitrogen stable isotope modelling to assess dietary mercury exposure for pregnant women in Baja California Sur, Mexico

IntroductionPrevious studies of mercury (Hg) in pregnant women in the area of La Paz, Baja California Sur (BCS), Mexico found a proportion of individuals had concentrations of total Hg ([THg]) above some thresholds of concern set by health agencies. The [THg] were associated with fish and seafood consumption as well as other factors; although it was unclear which marine diet items could potentially be contributing to the concentrations observed. MethodWe examined [THg] and monomethylmercury concentration ([MeHg+]) in the archived hair of 70 pregnant women from BCS as well as in diet items including fish, shellfish, and staple items (rice, beans, corn, and flour). We measured stable isotopes of carbon and nitrogen and employed a Bayesian stable isotope mixing model to investigate the proportion of fish and seafood in the isotopic profiles of archived hair samples. ResultsConcentrations of Hg species were low in staple foods and ranged from below detection limit to 5.71 parts per billion (ppb) wet weight. In hair, geometric mean [THg] was 658 ppb and [MeHg+] was 395 ppb, which were lower than previous reports. Percent MeHg+ was positively correlated with higher δ15N values. ConclusionsThe largest carbon contributors to the diet of the study participants were corn and rice, and our analysis of fish contribution to diet varyingly agreed with the self-reported fish consumption. This report highlights the ability to discriminate potential sources of Hg from a diverse diet and the limitations of dietary recall studies.

Molecular characterization and phylogenetic analysis of a Squash leaf curl virus isolate from Baja California Sur, Mexico.

BackgroundThe begomovirus, squash leaf curl virus (SLCuV) is one of the causal agents of squash leaf curl (SLC) disease, which is among the most destructive diseases of cucurbit crops in tropical, subtropical, and semiarid regions worldwide. This disease was originally reported in the American continent with subsequent spread to the Mediterranean basin. Up to now, SLCuV has only been detected by PCR in Mexico. This study provides the first complete sequence of a Mexican SLCuV isolate from Baja California Sur (BCS). In addition, the genome of the virus was characterized, establishing its phylogenetic relationship with other SLCuV isolates.MethodsThe full genome (DNA-A and DNA-B) was amplified by rolling circle amplification, cloned and sequenced and the open reading frames (ORF) were annotated. Virus identification was performed according to the International Committee on Taxonomy of Viruses (ICTV) criteria for begomovirus species demarcation. To infer evolutionary relationship with other SLCuV isolates, phylogenetic and recombination analyses were performed.ResultsThe SLCuV-[MX-BCS-La Paz-16] genome (DNA-A and DNA-B) had 99% identity with SLCuV reference genomes. The phylogenetic analysis showed that SLCuV-[MX-BCS-La Paz-16] is closely related to SLCuV isolates from the Middle East (Egypt, Israel, Palestine and Lebanon). No evidence of interspecific recombination was determined and iterons were 100% identical in all isolates in the SLCuV clade.ConclusionsSLCuV-[MX-BCS-La Paz-16] showed low genetic variability in its genome, which could be due to a local adaptation process (isolate environment), suggesting that SLCuV isolates from the Middle East could have derived from the southwestern United States of America (USA) and northwestern Mexico.

Impacto Socioeconómico del Turismo de la ballena gris (Eschrichtius robustus), en dos localidades de la Reserva de la Biosfera El Vizcaíno, Baja California Sur, México

El turismo es una actividad que ha mostrado en los últimos años un crecimiento en localidades que cuentan con atractivos naturales, tratándose de actividades turísticas en comunidades rurales, como el avistamiento de ballenas grises en México, especialmente en Baja California Sur (BCS) se ha tratado de vestir a este turismo como “Sustentable”. El objetivo es analizar la calidad del servicio ofertado en el turismo de observación de ballena gris en dos ejidos de la Reserva de la Biosfera El Vizcaíno (REBIVI), así como los aspectos socioeconómicos de la población local que se beneficia con empleos directos del turismo y la presencia de servicios públicos en los ejidos. Para realizar el estudio se analizaron indicadores de la satisfacción del servicio turístico obtenidos mediante encuestas a los turistas. Asimismo, se analizaron los indicadores socioeconómicos que se obtuvieron tanto del levantamiento de encuestas a los pobladores locales, como del análisis de fuentes alternas como el Instituto Nacional de Estadística y Geografía (INEGI). Los resultados muestran que en ambas localidades el visitante mostró satisfacción con el servicio recibido, aunque presenten carencias en algunos servicios públicos y en mayores oportunidades de empleo en el sector turístico para los habitantes locales, lo que contradice el discurso de desarrollo social y económico del turismo sustentable en México. Al final del análisis efectuado se ofrecen recomendaciones pertinentes para incrementar los beneficios y la sustentabilidad de esta estratégica actividad ecoturística.

Assessing Human Health Risks Associated with Consumption of Metal Content in Shrimp from NW Mexico.

Shrimp of Farfantepenaeus californiensis (78 groups) and Litopenaeus stylirostris (14 groups) were caught in the northwestern fishing zones in Mexico during the 2014-2015 fishing season (September-February); both shrimp species have high commercial value. Muscle, hepatopancreas and exoskeleton were analyzed to determine their metal contents. For F. californiensis, the highest Cd, Pb and Zn contents were determined in specimens caught off the State of Baja California Sur (BCS) with 22.4 ± 8.9 (hepatopancreas), 2.83 ± 4.63 (muscle), and 748.5 ± 1567 (muscle) µg/g, in the regions off Mulegé, Los Cabos and Los Cabos, respectively. For L. stylirostris, the fishing zone of Comundú (BCS) showed higher Cd (12.3 ± 11.5µg/g), Cu (569.1 ± 646.5µg/g) and Zn (549.7 ± 400.7µg/g) contents; all values were determined in the hepatopancreas. Regarding the hazard quotient and total hazard quotient calculated in this study, the consumption of marine shrimp caught off NW Mexico does not represent a risk to human health (both < 1).

Seasonal Distribution of Bemisia tabaci (Hemiptera: Aleyrodidae) MEAM1 Species and Impact on Incidence of Begomoviral Diseases in Baja California Sur.

For more than four decades, the presence of the whitefly Bemisia tabaci Gennadius complex as a pest and transmitter of begomoviral diseases has been one of the most important phytopathological events in cultivated species worldwide. In addition, the number of whitefly species, as well as the viruses they transmit, has been increasing over time. In the state of Baja California Sur (BCS), Mexico, the diversity of B. tabaci has been delimited to MEAM1 and NW species, affecting mainly tomato, pepper, and squash. However, the relationship of these species with the dispersion of the begomoviruses previously detected in the study area is still unknown. In a 5-yr study (2012-2016), these species of whiteflies and begomoviruses were identified. Moreover, the recurrence, seasonal distribution, and impact they have on the spread of the begomoviral diseases were assessed. The identification of whiteflies was done targeting the mtCOI by PCR-DNA barcoding assay. For begomoviruses identification, a set of degenerate and specific primers targeting the IR region and CP gene were used. To determine seasonal abundance, monitoring was performed every 15 d by means of yellow traps. The MEAM1 species in all localities was observed with the highest peak population (>10 whiteflies/trap) from March to April. The guidelines for naming begomovirus species for the International Committee on Taxonomy of Viruses (ICTV) establish that the names when they are preceded by the acronym the whole name is in lowercase, not italicized (e.g. bean golden mosaic virus (BGMV)); when the name goes alone without the acronym then its capitalizes the first letter (e.g. Bean golden mosaic virus) and when these are referred to in a taxonomic sense they are italicized and the first letter is capitalized (e.g. Bean golden mosaic virus). This study provides details of the distribution and occurrence of MEAM1 species and diversity of begomoviruses that could be useful in disease management in BCS and worldwide.

Effects of damiana (Turnera diffusa; var. diffusa and var. aphrodisiaca) on diabetic rats

Turnera diffusa (damiana) grows wild in Baja California Sur (BCS), Mexico. It is traditionally used for its aphrodisiac effects and for diabetes treatment. Two varieties (var.) have been identified: diffusa and aphrodisiaca. To evaluate the effects of water-ethanol extracts from both varieties, measurements on blood glucose, body weight, biochemical parameters, and cell blood counts were performed in a diabetic rat model. Oxidative stress was also evaluated when var. diffusa was administered. No significant reductions in blood glucose levels, in biochemical parameters, or in cell blood counts with any variety of damiana were observed; however, it helped diabetic animals to keep their body weight. Damiana var. diffusa did not modify the mitochondrial nitric oxide levels and superoxide dismutase activity; however, thiobarbituric acid reactive species diminished. In conclusion, damiana can be utilized reliably in the management of diabetes because of its antioxidant potential; it promoted body weight loss in healthy animals and helped to preserve it in diabetes.

Medición de la sustentabilidad turística en una pequeña localidad costera a través de indicadores, barómetros y consulta a expertos

Los indicadores proporcionan pautas para mejorar la calidad de vida. A nivel nacional son escasos los estudios sobre turismo en pequeñas localidades costeras por ello, se tomo como caso de estudio a Cabo Pulmo, Baja California Sur (BCS), un destino importante debido a la presencia de arrecifes y enorme diversidad aprovechada con fines recreacionales pese a ello, existe poca información sobre su impacto en el bienestar local. El objetivo de esta investigación fue medir el grado de sustentabilidad turística de Cabo Pulmo, BCS, una pequeña localidad costera sujeta a protección ambiental.El método utilizado se baso en el perfeccionamiento de dos metodologías, una propuesta por la Unión Internacional para la Conservación de la Naturaleza (UICN) y otra propuesta por la Organización Mundial de Turismo (OMT) y la Secretaría de Turismo (SECTUR) a su vez para la generación de la información de los indicadores se aplicaron técnicas mixtas y posteriormente, se formularon y ponderaron escenarios mediante el Método Delphi.Los resultados para 46 indicadores (23 del componente social y 23 del ambiental) revelaron que el ISL promedio fue de 0.70 y al ajustarlo con base en cuatro criterios de ponderación propuestos por expertos, se obtuvo: ISLae₁=.73, ISLae₂=70, ISLae₃=.73, ISLae₄=.84, según los tres primeros escenarios se corrobora que Cabo Pulmo, BCS se situá en un nivel Bueno de sustentabilidad sin embargo de manera excepcional, en el último escenario se le cualificó en un nivel Alto o excelente. Del mismo modo, los principales hallazgos apuntan a que Cabo Pulmo, presenta cierto grado de rezago social. Tal situación, no es única de la localidad estudiada; si no que suele observarse en pequeñas localidades o áreas, cercanas a enormes polos de desarrollo turísticos.Al contrastar los resultados con otros estudios se encontró que el sitio analizado presenta el mismo nivel de sustentabilidad que entidades de México como BCS y se localiza por arriba de naciones como Sri Lanka, Bangladesh, Nepal, Pakistán y Bután. Por otra parte, debe considerarse que el valor promedio de los componentes se localizaron en el límite superior (en el caso del componente ambiental) e inferior (en el componente social) del nivel de categorización y una pequeña reducción de los valores, en ambos o algunos de los componentes, puede ocasionar que la localidad se ubique en un grado de sustentabilidad más pobre. Las principales recomendaciones son: 1) Poner especial cuidado en mejorar los indicadores categorizados como críticos por ejemplo: servicios de salud y educación, calidad del agua para uso doméstico, viviendas con drenaje, caminos en buen estado y la relación visitantes Vs habitantes y 2) Seguir generando información para evaluar la variación en el nivel de sustentabilidad local.

Reproductive biology of the leopard grouper Mycteroperca rosacea (Streets, 1877) in the coastal area of Santa Rosalia, BCS, Mexico

The leopard grouper Mycteroperca rosacea is endemic to northwestern Mexico. It has been classified as vulnerable by the IUCN since 2008. M. rosacea has high commercial value and is caught yearround in Baja California Sur (BCS). Biological information on this species, especially in its natural environment, is scarce, and the objective of this study was to analyze its reproductive biology in Santa Rosalia, BCS. A total of 345 specimens were collected from March 2014 to May 2015. The sex ratio was 2.0: 1.0 (females: males, P < 0.05). Population size at first maturity (L 50 ) was estimated at 40.77 cm TL; 37.31 cm TL for males and 42.44 cm TL for females. Gonadic development was synchronous by group, with a reproductive period occurring from March to May in 2014 and 2015 (at 20-23oC). The gonadosomatic index achieved maximum values in May 2014 and March 2015, as did the highest frequencies of mature and spawning individuals, indicating that there was a clear seasonal pattern of reproduction, and a negative correlation with temperature for both sexes. The hepatosomatic index and the condition index indicated that M. rosacea is not a species that requires storing of energy for reproductive events, as it seems to have food available year-round. Normal 0 21 false false false ES X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:Tabla normal; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; line-height:115%; mso-pagination:widow-orphan; font-size:12.0pt; mso-bidi-font-size:11.0pt; font-family:Times New Roman,serif; mso-bidi-font-family:Times New Roman; mso-bidi-theme-font:minor-bidi; mso-ansi-language:ES; mso-fareast-language:EN-US;}

Development of fisheries in Bahía Magdalena-Almejas: The need to explore new policies and management paradigms

Bahía Magdalena-Almejas (BMA) is one of the most important fishery zones in North-western Mexico that produces between 55 and 60% of the total annual catch of the State of Baja California Sur (BCS) Mexico, mainly from the catches by industrial fisheries of sardines and tuna. However, as many places in the world, this region is experimenting symptoms of resources overexploitation of due to the absence of a long-term vision of sustainability, a multi-fishery management strategy, and a lack of planning and regulation strategies for local fisheries. This paper documented the evolution of fishing activity using different governmental databases, interviews with fishers, and academic publications to identify short and medium term challenges, and to suggest management approaches that will contribute in the adaptation of strategies to promote the sustainable use of fishing resources and economic alternatives for fishermen's income diversification. The findings of this study confirm that Small Scale Fisheries (SSF) have played a major role in the economic development of BMA in recent years, conflicts between industrial and SSF fleets are arising as a result of overlapping working areas inside the bay, and changes in the relative importance of SSF. Although the majority of the population in the region depends almost completely on activities related to SSF, the economic and social aspects of these activities have been poorly documented; studies on this field became even more necessary. Based on the current scenario, it is urgent that fishing policies be adapted to new challenges such as efficient multi-active spatial management, a multi-fishery management scheme. Besides, intra-sectorial strategies and social development programs should be improved.

Effects of hurricane Odile on the infrastructure of Baja California Sur, Mexico

In September 2014, the state of Baja California Sur (BCS), Mexico, was struck by hurricane Odile. The hurricane caused extensive damage to the infrastructure of the state of BCS, where the energy and water supply were interrupted for several days. The direct economic impact was estimated to be more than 1654 million USD. Considering this damage, few days after the cyclonic event, a technical visit to BCS was carried out. The objective of this study is to present the relevant information on the performance of the infrastructure observed after the event, and to make recommendations in order to mitigate the effects of future cyclonic storms in Mexico, based on the observations during the technical visit. The main causes of damage were the use of materials for non-structural elements with a weak performance under high wind speeds, failures in the design and construction of connections of structural and non-structural elements, accumulated damage, lack of maintenance and impact of wind-born debris, as well as the absence of a building code in the region. Background information about meteorological and climatological aspects of the cyclones that have affected the southern region of BCS, the characteristics of hurricane Odile, the analysis of structural damages and the conclusions, are also presented.

Respuesta hidrológica al cambio climático en regiones áridas: caso de estudio en los Comondú, Baja California Sur, México

Background. Currently, climate change is one of the most relevant phenomena within the scientific environment; this change has been recorded as an increase in temperatures on a global scale. For the central zone of Baja California Sur (BCS), Mexico, climate models also indicate an increase in the frequency of extreme precipitation. The study area covers two towns (San Jose and San Miguel de Comondu) whose urban and rural areas are located in a ravine of approximately 16 km in length and up to 800 m in width. Goals. To carry out a historical, statistical analysis of the climatic variability and model the response of the Comondu stream to extreme precipitation events. Methods. Climatic variability was analyzed with databases from the Comondu weather station, operated by the National Meteorological Service (SMN). In addition, the runoff pattern in the Comondu stream was ascertained in the event of extreme precipitation events, similar to or close to events with a return time of 1000 years, using hydrological and hydraulic models of HEC-1 and HEC-RAS software. Results. In the case of Los Comondu, BCS, there is a clear upward trend in the 24-hour extreme precipitation data, which implies that the danger of flooding in populated areas and crops increases considerably. The occurrence of a 1000-year event would affect about 86,864 m2 of the urban area of both towns and 201,570 m2 of the area under cultivation. Conclusions. The results of our modeling indicate an increase in area, depth, and speed of the stream, increasing the risk of flooding in the lower areas of Los Comondu, BCS. Based on our modeling’s results, measures should be promoted to safeguard the population and the economy of Los Comondu.

Isolation and risk assessment of Geotrichum spp. in the white shrimp (Litopenaeus vannamei Boone, 1931) from culture ponds

The present study was done in order to identify the fungus invading some of the supralittoral ponds used for shrimp aquaculture in the CIBNOR facilities in La Paz, Baja California Sur (BCS), México during the summer season. From the walls and bottoms of the ponds, two strains of Geotrichum spp. were isolated and morphologically identified. Fungal adhesion towards hemocytes and primary cultures of various white shrimp (Litopeneaus vannamei) tissues (gill, tegument, and gut) was analyzed to determine infectivity. Extracellular protease, lipase, and amylase activity were evaluated as virulence factors. Survival of shrimp postlarvae (PL8) exposed to fungal culture supernatant or to their filaments was also investigated. The results showed that shrimp tegument cells and hemocytes were very susceptible to Geotrichum spp. invasion, and that this fungus provokes great mortality of post-larvae. Hence, Geotrichum spp. could be considered an opportunistic pathogen that might represent a serious health risk to shrimp in culture.

Associations between trace elements and clinical health parameters in the North Pacific loggerhead sea turtle (Caretta caretta) from Baja California Sur, Mexico.

This study investigated selected trace elements toxicity in sea turtles Caretta caretta population from Baja California Sur (BCS), Mexico, by analyzing associations among Zn, Se, Cu, As, Cd, Ni, Mn, Pb, and Hg with various biochemical parameters (packed cell volume, leukocytes, and selected blood parameters), and whether their concentrations could have an impact on the health status of sea turtles. Blood samples from 22 loggerhead (C. caretta) sea turtles from BCS, Mexico, were collected for trace elements on biochemistry parameter analyses. Significant associations among trace element levels and the biochemistry parameters were found: Cd vs ALP (R 2=0.874, p˂0.001), As vs ALP (R 2=0.656, p˂0.001), Mn vs ALP (R 2=0.834, p˂0.001), and Ni vs LDH (R 2=0.587, p˂0.001). This study is the first report of the biochemical parameters of the North Pacific loggerhead sea turtle (C. caretta) from Baja California Sur, Mexico, and it is the first to observe several associations with toxic and essential trace elements. Our study reinforces the usefulness of blood for the monitoring of the levels of contaminating elements and the results suggest that, based on the associations with health clinical parameters, high levels of Cd and As could be representing a risk to the North Pacific loggerhead population health.

Hydrogeochemical characterization of the thermal springs in northeastern of Los Cabos Block, Baja California Sur, México.

The existence of hot springs in the northeastern part of Los Cabos Baja California Sur (BCS), is known from pre-Hispanic times, but their hydrochemical composition had not been previously described. Several springs are located within the watershed of Santiago, and the objective of this study was to define the hydrogeochemical composition of the thermal springs and to characterize the geothermal reservoir. A total of 16 water samples were taken in 11 geothermal manifestations under dry (June 2014) and humid (March 2015) conditions. A geothermal system of low enthalpy and low mineralization was found along the San José del Cabo Fault (FSJC), with an average salinity (TDS) of 261mg/L and an alkaline pH (8.5-9.5). The hydrogeochemical composition corresponds to the sodium-bicarbonate type, and geothermometers (silica and Na-K) indicate temperatures ranging from 70 to 115°C for the deep thermal reservoir in conditions of equilibrium. The thermal springs with these hydrogeochemical characteristics differ in respect to the hydrochemical composition of the springs, formally described on several sites of BCS. Br/Cl and B/Cl ratios as well as the enrichment factor (EF) indicate that rainwater with a seawater component represents the source of the thermal spring water. In the springs, a mixture between thermal water and surface water is observed, combined with a relatively deep water circulation, allowing a calcium-sodium exchange, according to the host rock geochemistry. The higher temperatures found at some hot springs are related to the main trace of the San José del Cabo Fault.

First Record of Fibropapillomatosis in a Green Turtle Chelonia mydas from the Baja California Peninsula

Fibropapillomatosis (FP) is characterized by multiple fibroepithelial tumors in all parts of the skin and has been reported in sea turtles worldwide. Clinically infected individuals are often emaciated and anemic. In Mexico, however, there are few records of this disease. In this study of green turtles Chelonia mydas in Laguna San Ignacio in Baja California Sur (BCS), we noted one juvenile with multifocal fibropapilloma lesions on the external upper surface of its eyes and hind flippers. Light microscopy revealed hyperkeratosis, epidermal hyperplasia, dermal papillary projections, and fibroblast proliferation. Electron microscopy revealed viral particles. Biopsies of normal skin were done to determine the origin of the turtle through genetic analysis. Its mitochondrial DNA matched that of a haplotype (CMP2) from a Hawaiian green turtle population. Finding FP in a turtle captured in BCS elucidates the need for further monitoring along the west coast of Mexico. Further investigation should include testing tumors to detect and characterize any chelonid herpesviruses and explore any association with FP and other diseases that pose a health risk to other sea turtle species. Received March 26, 2016; accepted August 3, 2016.

Cestodes of the blue shark, Prionace glauca (Linnaeus 1758),(Carcharhiniformes: Carcharhinidae), off the west coast of Baja California Sur, Mexico.

The cestode species recovered from the spiral intestines of 27 blue sharks (Prionace glauca) (Linnaeus, 1758) are reported from the western coast of Baja California Sur (BCS). The sampling was undertaken on a monthly basis from January 2003 to January 2004. The helminthological examination indicated the presence of four species of cestodes: Platybothrium auriculatum Yamaguti, 1952; Prosobothrium japonicum Yamaguti, 1934; Anthobothrium caseyi (Yamaguti, 1934) Ruhnke & Caira, 2009; and Paraorygmatobothrium prionacis (Yamaguti, 1934) Ruhnke, 1994. Of all the 27 sharks examined, 88.8% were infected with at least one cestode species. The most frequent species was P. auriculatum infecting 85% of the spiral intestines examined. In contrast the species with the highest mean intensity was P. prionacis (80.4 200). The species richness of cestodes in P. glauca is very similar in other regions of the world despite its wide distribution; however, this richness is low compared with other species of sharks within the same family. The feeding and host-specific are important factors that influence the parameters of infection of cestodes in this shark. On the west coast of BCS, Prionace glauca feeds mainly on red crab Pleuroncodes planipes Stimpson, 1860; squids Gonatus californiensis Young, 1972, Ancistrocheirus lesueurii (D'Orbigny, 1842), Haliphron atlanticus Steenstrup, 1861, and low proportion of fish teleosts as Merluccius productus (Ayres, 1855), Sardinops sp. Hubbs, 1929 and Scomber japonicus Houttuyn, 1872. We speculate that these prey could be involved as the second intermediate hosts of these cestodes, as in other members of these genera, although the life cycles of none are known.