How Biological Data Has Contributed to Management Plans in the Bay of La Paz: Los Islotes Sea Lion Rookery as Case of Study

Los Islotes is the southernmost breeding site of the California sea lion (Zalophus californianus) in Northern Hemisphere and represents one of the most important economic activities for the city of La Paz, Mexico. The increasing tourism activity grew without any control until researchers and organizations started to be concerned about the perturbation to the reproductive and haul-out patterns of the sea lion. The International Conservation Program of The Nature Conservancy funded a research project, with the goal to determine the effect of tourism activities on the behavior of sea lions, in order to help design regulations to assure better use and conservation of the site. The nature and intensity of tourism activity and the effects to the sea lion behavior were determined based upon monthly sampling over a one-year period (May 2000-April 2001). The main result was that perturbations occurred mostly in autumn and winter coinciding with the highest frequency of tourism, large number of male sea lions, increasing suckling behavior of pups, and unfavorable environmental conditions for haul-out, such as high tide level and strong winds. Researchers, service tourism providers, and governmental personnel collaborated and participated in workshops organized by the regional office, CONANP-SEMARNAT, in order to develop a regulation plan with a buoy system and zoning specifications for tourism activities. Some of the former management strategies are in current force in conservation management plans in the area. Current needs for conservation physiology studies relative to changes in tourism and fishing activities will also be discussed.

Ecoturismo marino en el golfo de California y península de Baja California: tendencias de investigación y vacíos de información

Achieving equitable and sustainable ecotourism requires a wide range of multidisciplinary and cross-scale information, particularly given the growing scale of ecotourism operations and continuing governance and climate challenges. Ecosystems in Mexico’s Gulf of California and Baja California Peninsula support a thriving ecotourism industry that has quickly expanded over the last few decades, potentially outpacing research into current performance and future sustainable development opportunities. We develop and apply a formal literature review approach to characterize academic marine ecotourism literature, highlight key insights and identify research strengths and gaps, and thus analyse almost 50 publications for the region from 1994 to 2014. There has been a significant increase in the number of various types of publications; most (68%) focus on ecological themes, 25% on economics, and 7% on social aspects of human wellbeing. There are also trends towards research on specific species (e.g. mammals, fish and sharks) and in specific areas. A common theme in publication conclusions is the need for collaboration from all stakeholder groups. We discuss these findings, and address potential limitations of our method, with a view to informing sound policies to ensure that ecotourism can provide equitable benefits to local communities while incentivizing sustainable practices and nature conservation.El desarrollo equitativo y sostenible del ecoturismo debe considerar una amplia gama de información multidisciplinaria y a varias escalas, particularmente dada la creciente magnitud de las operaciones de ecoturismo y los retos de gobernanza y climáticos. Los ecosistemas en el golfo de California y península de Baja California en México mantienen a una próspera industria de ecoturismo que se ha expandido rápidamente a lo largo de las últimas décadas, posiblemente dejando atrás a la investigación respecto a sus operaciones actuales y las oportunidades para el desarrollo sostenible a futuro. Desarrollamos y aplicamos una revisión formal de literatura para caracterizar a las publicaciones académicas respecto al ecoturismo, señalar tendencias clave e identificar fortalezas y vacíos de investigación, analizando casi 50 publicaciones para la región desde 1994 al 2014. Ha habido un incremento significativo en la cantidad de publicaciones de varios tipos; la mayoría (68%) se enfocan en temas ecológicos, 25% en economía y 7% en aspectos sociales del bienestar humano. También existe una tendencia hacia investigación de ciertas especies (e.g. mamíferos, peces, tiburones) y en regiones específicas. Un tema común en las conclusiones de las publicaciones analizadas es la necesidad de colaboración por todos los grupos de actores. Discutimos estos resultados, y las posibles limitaciones de nuestro método, en el contexto de informar políticas adecuadas para asegurar que el ecoturismo pueda proveer beneficios equitativos a comunidades locales al mismo tiempo que se incentivan las prácticas sostenibles y la conservación de la naturaleza

Endoparasitic infections in captive wild mammals under human care in San Luis Potosí, Mexico

Objective: Determine parasite prevalence, richness and load in wild mammals of Tangamanga I and II Parks in San Luis Potosí, SLP. Evaluate if infections are related to diet and/or climatic seasons. Design/methodology/approach: Analysis of fresh feces collected during three consecutive days in two sampling periods. Passive flotation techniques with sodium nitrate (qualitative) and McMaster (quantitative) were performed. Results: General prevalence observed was 36% (n=242). The parasite richness is formed by protozoa: Eimeria sp, Isospora sp and Cystoisospora sp; by the cestode Moniezia expansa and nematodes: Toxocara sp, Toxascaris sp, Ancylostoma sp/Uncinaria sp, Strongyloides sp, Trichuris suis and eggs from the Strongyles group. The parasite load observed in the case of protozoa ranged from 0 – 8,505 Oocysts per Gram of Feces, and from 0 – 1,400 Eggs per Gram of Feces in the case of helminths. Statistical analyzes showed that the prevalence of parasites does not depend on the climatic season, and only in Tangamanga II Park is the prevalence dependent on the diet (herbivores). Study limitations/implications: The preservation method used limits the coproparasitoscopic techniques that can be used (coproculture or coccidia sporulation). Findings/conclusions: The observed endoparasitic infections can be a potential risk to the health of animals, especially those of great genetic value (i.e., endangered species). In addition, the potentially zoonotic parasites observed represent a threat to the health of their keepers.Objective: To determine the prevalence, richness and parasitic load in wild mammals of Tangamanga I and II Parks in San Luis Potosí, SLP. To assess whether infections are related to the type of feeding and weather seasons. Design/methodology/approach: Analysis of fresh feces collected for three consecutive days at two sampling stations. Passive flotation techniques with sodium nitrate (qualitative) and McMaster (quantitative) were used. Results: The overall prevalence observed was 36% (n=242). The parasitic wealth is formed by protozoa: Eimeria sp., Isospora sp. and Cystoisospora sp.; by the cestode Moniezia expansa, nematodes: Toxocara sp., Toxascaris sp., Ancylostoma sp./Uncinaria sp., Strongyloides sp., Trichuris suis and Strongylid eggs. The parasite load in the case of protozoa was in the range of 0 – 8505 oocysts per gram of faeces, and 0 – 1400 eggs per gram of faeces in the case of helminths. Statistical analyses showed that the prevalence of parasites does not depend on the climatic season, and only in Tangamanga II Park is the prevalence dependent on the type of feeding (herbivores). Study limitations/implications: The conservation method used limits the stool test techniques that can be employed (stool culture or sporulation). Findings/conclusions: Endoparasitic infections can be a potential risk to the health of animals. In particular to those of great genetic value such as species threatened with extinction. In addition, the potentially zoonotic parasites observed pose a threat to the health of caregiver

Influencia del turismo sobre la conducta del lobo marino de california Zaluphus californianus en la lobera Los Islotes, B.C.S., México.

impreso y digita

Plasmatic B-esterases as potential biomarkers of exposure to marine plastics in loggerhead turtles

7 pages, 1 figure, 3 tablesSea turtles are particularly vulnerable to plastic exposures, and the associated chemical additives, due to their feeding strategies. The species Caretta caretta is a proposed sentinel of plastic pollution worldwide. Thus, there is a need to find adequate biomarkers of plastic exposure through non-invasive protocols for this IUCN protected species. Plasmatic acetylcholinesterase (AChE), butyrylcholinesterase (BuChE) and carboxylesterase (CE) which participate in xenobiotic and endogenous metabolic reactions could all serve as biomarkers, as they are responsive to plasticizers and have already proved adequate for identifying organophosphorus esters exposures. Here we measured plasmatic B-esterases in wild specimens captured as accidental by-catch. Measurements were taken in each individual either at entry into the rehabilitation program or immediately before release after a recovery period. For CE measurements, 4 commercial substrates were used as potentially indicative of distinct enzyme isoforms. Increased activity was seen with the butyrate-derived substrates. Plasmatic CE activities were over one order of magnitude higher than AChE and BuChE substrates. Moreover, an in vitro protocol with the inclusion of plastic additives such as tetrabromobisphenol A (TBBPA), bisphenol A and some of its analogues was considered a proxy of enzymatic interactions. A clear inhibition by TBBPA was found when using commercially purified AChE and recombinant CE proteins. Overall, from in vitro and in vivo evidences, CEs in plasma are sensitive and easily measurable and have been shown to significantly increase after turtles have been rehabilitated in rescue centres. Nevertheless, the inclusion of plastic (or plasticizers) characterisation would help to confirm its association with plasmatic enzyme modifications before they can be adopted as biomarkers of plastic contaminationMS and VLM are members of the RIESCOS network - Red Iberoamericana Evaluación de los efectos de los Contaminantes emergentes en Organismos acuáticos y sobre Salud humana, from Programa Iberoamericano de Ciencia y Tecnología para el Desarrollo (CYTED). We thank the Community Regional Government and the Servei de fauna i flora de la Generalitat de Catalunya of the Catalan Community regional Government and the institutional support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX 2019-000928-S). This work has received funding from CSIC Interdisciplinary Thematic Platform (PTI+) Interdisciplinary Platform for Sustainable Plastics towards a Circular Economy+ (PTI-SusPlast+)Peer reviewe

Relation of dental wear to the concentrations of essential minerals in teeth of the California sea lion Zalophus californianus californianus

Tooth wear in marine mammals has been attributed to age, feeding habits, behavior, and contaminants. Advanced tooth wear in some California sea lions, including some of very young age (<5 yr), in the Gulf of California, suggests that there are variations in chemical composition of tooth parts, wherein the concentrations of certain trace minerals might be anomalous, making them more susceptible to erosion. The concentrations of the essential minerals Ca, P, K, Na, Fe, Mg, and Zn in the dentition of Zalophus c. californianus are documented for the first time and are compared for sea lion teeth with different degrees of wear. Canine teeth and molars from 45 skulls collected at 15 localities since 1978 were digested in perchloric acid and analyzed using atomic adsorption spectrometry, the results being expressed in milligrams per 100 g. An index of tooth wear (Id) was established, involving the average wear on the teeth and the age of the organism. No significant difference was detected in the variables, but there was one between ages (p=0.02). A higher degree of wear was observed up to 7 yr of age than from this age onward. Mineral concentrations did not explain the excessive wear observed (correlation, p>0.09; ANOVA, p>0.15); however, the Ca concentration of the teeth was inversely proportional to the age of the animal (sexes combined, p=0.026) and particularly significant for the females (r 2=0.112, r=−0.335, p=0.039). Females could be more prone to decalcification because of their annual bone investment in their offspring. Animals of both sexes were susceptible to tooth wear as their age increased, but the higher frequency of animals between 4 and 7 yr suggests an impact on survival at early stages probably linked to deficient feeding and chronic malnutrition

Natural and human disturbance in a rookery of the California sea lion (Zalophus californianus californianus) in the Gulf of California, Mexico

Los Islotes is the southernmost breeding site of the California sea lion (Zalophus californianus californianus) in the Northern Hemisphere and represents one of the principal tourist attractions for the city of La Paz, Mexico. The tourism has been growing without control and could be the cause of perturbation in the reproductive and haul-out patterns of the sea lion. The aim of the present study was to determine the effect of tourism activities on the behavior of sea lions, in order to help design regulations to assure better use and conservation of the site. The nature and intensity of tourism activity and sea lion behavior were determined based upon monthly sampling over a one-year period (May 2000 - April 2001). Tourist activity was higher during autumn and winter, with visits by 'panga' boats being the most numerous. A total of 112 disturbances were recorded, the majority of which being non-anthropogenic causes. A quarter of disturbances were triggered by human activity within 20m of the rookery and with harassment reaction (animals going into the water) in 32% of the anthropogenic disturbances. Principal component analysis (PCA) described the conditions under which disturbance was generated (74% of the variation explained). Using three factors (47% of the total variation) the major contributing variables were month, tidal level, relative humidity, Beaufort number, total number of boats and number of powerboats and sailboats. In Los Islotes, the perturbation occurs mostly in autumn and winter coinciding with the highest frequency of tourism, large number of adult and subadult males and unfavorable environmental conditions for haul-out, such as high tide level and strong winds. The lowest number of disturbances occurred in summer, during the breeding season of the sea lion. Most of these, however, were caused by human activity

Determinación de la actividad de la acetilcolinesterasa en plasma de tortuga blanca (Chelonia mydas) como potencial biomarcador de perturbación ambiental

6ª Reunión Nacional sobre Conservación de Tortugas Marinas en México, celebrada del 3 al 5 de noviembre de 2021, Quintana Roo, MéxicoEn Quintana Roo la principal actividad económica es el turismo. Sus costas son hábitat de forrajeo, desarrollo y reproducción de la tortuga blanca (Chelonia mydas), una especie en peligro crítico (NOM-059-SEMARNAT-2010). La exposición a contaminantes químicos, producto del desarrollo costero, genera estrés oxidativo en tortugas marinas. La actividad de acetilcolinesterasa (AChE), una enzima que participa en la sinapsis nerviosa, puede alterarse por la exposición a plaguicidas y, en conjunto con los indicadores de estrés oxidativo, la AChE podría evidenciar la exposición a químicos neurotóxicos. El objetivo de este estudio fue cuantificar y evaluar la relación de la actividad de AChE con los indicadores de estrés oxidativo y talla de tortugas blancas capturadas (2019) en la costa de Quintana Roo (Akumal, Punta Herrero y Xcalac). Se cuantificó la tasa de producción de radical superóxido (O2¿¯), la actividad de AChE, la actividad de enzimas antioxidantes (glutatión S-transferasa (GST), glutatión peroxidasa (GPx), glutatión reductasa (GR) y catalasa (CAT)) y la concentración de sustancias reactivas al ácido tiobarbitúrico (TBARS) en eritrocitos de 34 individuos. Las tortugas capturadas fueron inmaduras con un índice de condición corporal >1.2. La actividad de GR, GST y GPx y la producción de O2¿¯ presentaron diferencias significativas entre zonas, siendo mayores en Akumal y Xcalac. La actividad de AChE se correlacionó positivamente con los niveles de TBARS y la producción de O2¿¯. Los resultados sugieren que la AChE muestra sensibilidad como potencial biomarcador de exposición a diferentes niveles de perturbación ambiental con C. mydas como especie indicador