Cozumel Research Articles

ESTUDIO EPIDEMIOLÓGICO DE PARÁSITOS EN HECES DE PERROS EN PARQUES DE COZUMEL, QUINTANA ROO, MÉXICO

<p><strong>Background: </strong>Contamination of public spaces with canine feces containing parasites increases the possibility of transmission of these parasites to people and other canines. <strong>Objective: </strong>To estimate the frequency and variables associated with parasite eggs/oocysts in canine feces collected in public parks from Cozumel Island, Mexico. <strong>Material and methods:</strong> One hundred and fifteen stool samples were collected in 23 public parks, which were selected by convenience and analyzed by direct smear microscopy. The variables evaluated were i) with/without tourism, ii) low/high economic level), iii) high/low number of inhabitants and iv) area collection site paved/unpaved. A statistical association analysis test (Χ<sup>2</sup>) was performed to determine significance of results and the odds ratio (OR) between the studied variables was evaluated. <strong>Results: </strong>A parasite prevalence of 27% was found, recording the following order of species <em>Ancylostoma</em> spp > <em>Trichuris</em> spp > <em>Toxocara </em>spp > <em>Isospora</em> spp = <em>Taenia </em>spp. Statistical significance was not found in the X<sup>2</sup> tests and ORs. The positive sample frequencies of the variables evaluated did not show any correlation, irrespective of the parasite reported. <strong>Implications:</strong> Stray dogs, pet dogs, people and pet owners visiting public parks of Cozumel Island, Mexico, could be infected by gastrointestinal parasites. <strong>Conclusion:</strong> In public parks from Cozumel Island, gastrointestinal parasite eggs/oocysts are present in canine feces. However, the variables evaluated did correlate with the presence of these parasites.</p>

The condition status index for doline lakes in urban areas

Karst represents approximately 15% of the planet’s surface, hundreds of millions of people live on and rely on these aquifers for water supply and agricultural irrigation. In karstic landscapes, groundwater is exposed in sinkholes, inundated caves, and artesian wells, which are two-way communication spots. When the phreatic level is exposed, the groundwater can change substantially as a result of anthropogenic impacts, modifying the water quality and the environmental integrity by incoming excess nutrients, contaminants, pathogens, and other hazardous substances such as metals and microplastics. In this paper, we develop and test a multimetric index to evaluate the condition status of dolines located within urban areas, including seven indicators: trophic index, fecal bacteria, fecal viruses, microplastics, heavy metals, zooplankton biodiversity, and fish biodiversity. Lastly, we made a proof of concept for the index in the dolines on the island of Cozumel (Mexico), resulting in evaluations from fair to good. The index is powerful due to its sensitivity to pathogens and exotic invasive species. This additive weighted index allows to assess the condition status of dolines in urban areas anywhere in the world; if required, modifications are possible.

Cryptic diversity patterns of subterranean estuaries.

Subterranean estuaries are coastal ecosystems characterized by vertically stratified groundwater. The biota within these ecosystems is relatively understudied due to the inherent difficulty of accessing such extreme environments. The fauna inhabiting these ecosystems is considered vulnerable to extinction, and the presence of cryptic species has major implications for research and conservation efforts. Most species lack molecular data; however, the evaluation of genetic data for some taxa has revealed that undocumented species are common. This study employs molecular species delimitation methods and DNA barcoding through the analysis of publicly and newly generated sequences, including individuals from type localities and non-crustacean phyla; the latter are typically overlooked in biodiversity assessments of subterranean estuaries. We analysed 376 cytochrome c oxidase subunit I (COI) gene sequences and 154 16S rRNA gene sequences. The COI sequences represented 32% of previously described species and 50% of stygobiont species from the Yucatan Peninsula and Cozumel Island, while sequences of the 16S rRNA represented 14% of described species and 22% of stygobionts. Our results revealed cryptic genetic lineages and taxonomic misidentification of species. As several species from these ecosystems are recognized as endangered, the use of molecular approaches will improve biodiversity estimates and highlight overlooked cryptic lineages in need of evaluation of conservation status.

Correction: Urban colonization of invasive species on islands: Mus musculus and Rattus rattus genetics of establishment on Cozumel Island

Correction: Urban colonization of invasive species on islands: Mus musculus and Rattus rattus genetics of establishment on Cozumel Island

Urban colonization of invasive species on islands: Mus musculus and Rattus rattus genetics of establishment on Cozumel Island

Humans and wildlife experience complex interactions in urban ecosystems, favoring the presence of commensal species, among which invasive species are particularly successful. Rodents are the main vertebrate group introduced to oceanic islands, where the invasion process and dispersal patterns strongly influence their evolutionary and genetic patterns. We evaluated the house mouse Mus musculus and the black rat Rattus rattus on Cozumel Island, Mexico. We assessed genetic diversity and structure, connectivity, gene flow, relatedness and bottleneck signals based on microsatellite loci. Our genetic findings suggest that introduction of individuals of different geographic sources to the island promotes high allelic diversity and the effective establishment of migrants. We identified a clear genetic structure and low connectivity for the two species, tightly linked with anthropogenic and urban features. Notably, we found that the genetic structure of the house mouse sampled within the city of San Miguel Cozumel is associated with the historical human population growth pulses accompanying the urbanization of the city. At the fine-scale genetic level, the main urban drivers of connectivity of the house mouse were both the impervious land surfaces, i.e. the urban landscape, and the informal commerce across the city (a proxy of resources availability). Chances of a secondary invasion to natural environments have been relatively low, which is crucial for the endemic taxa of the island. Nonetheless, improving urban planning to regulate future expansions of San Miguel Cozumel is of the outmost importance to prevent these invasive species to disperse further.

Big eyes on the Island: First record of Chiroderma villosum of Cozumel Island, México and bat species richness in the Caribbean islands

El registro más cercano de Chiroderma villosum a Isla Cozumel, está documentado en la ciudad de Playa del Carmen, Quintana Roo. En este trabajo documentamos el primer registro del murciélago C. villosum para Isla Cozumel y compilamos la información sobre la riqueza de especies de murciélagos en las Islas del Caribe. El 5 de mayo de 2021 se realizó una salida de campo, se instalaron redes de niebla a nivel del suelo. Posteriormente se tomaron los siguientes datos de cada individuo capturado: medidas del antebrazo con un vernier con una precisión de 1 mm, se tomó el peso con una báscula digital con precisión de 1 g, y se identificó la especie siguiendo la clave de murciélagos de México. Durante la noche de trabajo se capturaron 8 individuos de Artibeus jamaicensis y un ejemplar macho adulto no reproductivo de C. villosum a las 21:45 hr en una red de niebla colocada cruzando una brecha dentro de la selva mediana en el noroeste de la zona arqueológica de San Gervasio. En Isla Cozumel se han documentado 19 especies de murciélagos correspondientes a 5 familias y 15 géneros. Con el registro de este espécimen, se incrementa a 20 el número de especies y a 16 géneros de quirópteros presentes en la isla. Aunque todavía faltan más estudios, es muy probable que esta especie tenga una distribución amplia en todas las áreas de bosque en Cozumel.

An investigation into the Pelagic Sargassum incursion phenomenon: A study of seaweed coastal influxes on Cozumel Island, Mexico

The <i>Pelagic Sargassum</i> influx problem in Mexico and other Caribbean countries began in 2011 when seaweed arrived in extreme quantities on Mexican Caribbean coastlines. As coastal areas produce resources like fisheries, tourism, and raw materials, this creates problems for the surrounding businesses. <i>Sargassum</i> thrives in the Atlantic Ocean due to eutrophication, and the ocean conditions promote the shifting of these seaweed mats. This work aims to study <i>Sargassum</i> arrivals on Cozumel Island coasts and examine coastal lines disposition to receive the seaweed. From our findings, it was understood the importance of a good handling policy in the country and the disposition of sandy-type beaches to accumulate more <i>Sargassum</i>.

Entomological Survey and Leishmania (Leishmania) mexicana Prevalence in Sand Fly Species during an Outbreak of Cutaneous Leishmaniasis in Quintana Roo State, Mexico.

(1) Background: Localized cutaneous leishmaniasis is a neglected vector-borne disease that has become a serious public health problem in the Yucatan Peninsula. Although more than 60% of cases originate from the state of Quintana Roo, it is one of the least explored areas in terms of incriminating vectors of the Leishmania parasite. Additionally, cases of leishmaniasis have increased substantially in that region in recent years. For this reason, we explored and provided primary evidence of Leishmania DNA in sand fly species from four localities during outbreaks of leishmaniasis in Quintana Roo. We also contributed information on the regional genetic diversity of Leishmania parasites. (2) Methods: Sand flies were collected during several periods from November 2022 to April 2023 using Mosquito Light Circle and Shannon traps, as well as an active entomological search in refuges. For Leishmania detection, we amplified a fragment of 300-350 bp of the internal transcribed spacer subunit 1 (ITS-1). (3) Results: Of the 242 females collected, we detected Leishmania DNA in 25 specimens represented by Bichromomyia olmeca (1), Psathyromyia shannoni (17), Lutzomyia cruciata (4), Psathyromyia undulata (2), and Dampfomyia deleoni (1). The detection of Leishmania in these last two species represents new records for the Yucatan Peninsula and for Mexico. Leishmania (Leishmania) mexicana was the only species detected in the Phlebotominae species, with prevalence values that ranked between 7.41% and 33.33% from specimens collected in the sylvatic areas of Cozumel Island and Petcacab. (4) Conclusions: This study provides the first evidence of infection of Da. deleoni and Pa. undulata by L. (L.) Mexicana. In addition, the presence of three dominant haplotypes in all the evaluated localities was evidenced using the analysis of genetic diversity, and the locality of Petcacab was the one with the circulation of two new haplotypes not previously described in Mexico or neighboring countries. These results highlight the importance of intensive epidemiological surveillance due to the dynamics of transmission of Leishmania between different species.

Sargassum transport towards Mexican Caribbean shores: Numerical modeling for research and forecasting

A cost-effective particle-tracking model was implemented to study the transport and landing of sargassum in the Mexican Caribbean. Sensitivity analyses were performed to quantify the change in landing percentages varying some model factors: 1) windage factor, 2) the horizontal distribution of sargassum, 3) monthly variability of currents and winds, 4) sargassum growth, 5) thickness of the transporting ocean layer, 6) wind data source, and 7) ocean data source. The windage factor had the greatest effect on landing estimates: as it increased, the sargassum landing percentage increased by 19%. In second place, differences in the initial horizontal distribution of sargassum caused the landing percentage to change by ∼10%. In third place, the monthly variability of currents and winds changed the landing percentage by 6%. The northern shoreline of Mexican Caribbean (between 20.25°N and 20.75°N) was the most prone to sargassum landings. At the regional scale, this condition is related with a) the shoreline orientation in that region, which more clearly faces the northward flow of the Yucatán Current, and b) the position of Cozumel Island, which acts as an offshore barrier capturing sargassum. Most of landed sargassum in the Mexican Caribbean had floated 0–40 km east and south of Chinchorro Bank, within 18.25°N and 18.75°N (southern Mexican Caribbean), and then spread along the shore. Monitoring, containment, and collection of sargassum east and south of Chinchorro Bank could help predict and mitigate sargassum landings about 5 days in advance.

Assessment of Socioeconomic Resilience to Pandemic Disasters in Island Tourist Destinations

The pandemic has led to a sharp contraction in economic activity with diverse businesses shutting down or reducing their operations. The COVID-19 pandemic is recognized as a challenge in the travel and tourism services industry. Therefore, this paper aims to evaluate the socioeconomic resilience of the island tourist destination of Cozumel and to determine its ability to manage a pandemic by identifying its strengths and weaknesses. This study was based on the Indicators of Socioeconomic Resilience in Island Destinations (ISRID) matrix adapted to the study territory to achieve this aim. As a result, 63 out of 890 research articles were reviewed, from which 1222 indicators were collected; nevertheless, only thirty-three indicators were selected. The assessment was also structured on a matrix of double data collection before and after the pandemic to analyze the evolution of the components essential to strengthening socioeconomic resilience. In this way, this study revealed that the island of Cozumel does not have good risk management in the presence of a pandemic phenomenon. Thus, the principal axes to reinforce abilities were implementing a comprehensive plan with multidisciplinary approaches containing themes like social participation, access to information, health, economic resources, gender inequalities, marginalization, environmental impacts, and endemic resources. Finally, the matrix developed can aid decision-makers in generating corresponding actions when designing, implementing, and evaluating socioeconomic resilience capacities to cope with a pandemic disaster in island tourist destinations.

Multi-character approach reveals a new mangrove population of the Yellow Warbler complex, Setophaga petechia, on Cozumel Island, Mexico.

The Setophaga petechia complex includes 43 subspecies distributed within the new world, of which some are migratory and others are resident, with only two resident subspecies in the Mexican Caribbean: Setophaga petechia bryanti a mangrove subspecies belonging to the erithachorides group resident on the mainland of the Yucatan Peninsula and Setophaga petechia rufivertex endemic to Cozumel Island and belonging to the petechia group. Recently, a new population of individuals presenting intermediate phenotypic traits and living in mangrove ecosystems was discovered and reported for Cozumel Island. In this study, we used a multi-character approach including genetic (five ISSR genetic markers), morphometric (eight traits), phenotypic (four characteristics of males), and acoustic dataset (11 parameters) to understand the process of differentiation and the status of these new island individuals in relation to the two well-established subspecies using a total of 60 individuals (20 for each group). Through multivariate analyses based on different dataset used in our study, we show how the new population is related to the endemic island subspecies, S. p. rufivertex and to the mainland subspecies, S. p. bryanti while demonstrating finite differences. We conclude that the new population of S. petechia on Cozumel Island is a well-established population with high level of differentiation.

Alien and Potentially Invasive Plants in Four Lagoons on the Island of Cozumel, Mexico.

The expansion of alien invasive species is a worldwide threat that affects most ecosystems. Islands and freshwater ecosystems are among the most vulnerable to species invasion, resulting in reduced biodiversity. In this study, we aimed to explore the floristic composition of the aquatic vegetation in four lagoons in southeastern Cozumel and assess the occurrence and abundance of alien and potentially invasive plants. We found a total of 43 aquatic or underwater herbaceous species that are subject to periodic flooding. Cluster analyses grouped the lagoons into two groups according to their floristic composition. The results demonstrate that alien and potentially invasive plants were dominant in 3 of the 4 lagoons, representing from 7 to 43% of the species. Six of these species were notably abundant, especially in three lagoons. Further, 2 species are considered among the 100 worst invasive species worldwide, although their abundance in Mexico remains relatively reduced. Five alien and potentially invasive species are terrestrial and grow on the shore of the lagoons, while one is aquatic. Urgent control and management actions are necessary. These should include (a) early detection and surveillance to determine if the alien species found behave as invasives; (b) understanding the relevance of invasive species; (c) preventing and intercepting; and (d) control and management. Habitat restoration, adequate legislation, collaboration between stakeholders, and raising awareness of the dangers of releasing or cultivating invasive species in the wild are also necessary.

First detailed record of food items in the diet of the dwarf coati (Nasua nelsoni) of Cozumel Island, México

Introducción: El coatí enano (Nasua nelsoni) es un mamífero endémico de Isla Cozumel, Quintana Roo, México. A pesar de que el coatí enano es una especie seriamente amenazada con la extinción, aún existen serios vacíos de conocimiento sobre su biología y ecología. Se desconocen aspectos relevantes de su ecología trófica y no existe información específica sobre sus hábitos alimentarios. Por ello, nuestro objetivo fue reportar, por primera vez, detalles sobre los alimentos que conforman parte de la dieta del coatí enano. Métodos: Entre septiembre de 2013 y diciembre de 2014, registramos avistamientos de grupos e individuos solitarios de coatí enano. Algunos de estos avistamientos nos permitieron registrar directamente el consumo de alimentos, principalmente frutas, que luego fueron identificados mediante la recolección de muestras del material consumido y de la planta madre. Resultados: Registramos 25 avistamientos de individuos de coatí enano mientras consumían alimentos. En 88 % (n = 22) de esos avistamientos, registramos el consumo de frutos de 8 especies, representadas por 8 familias de plantas silvestres. Adicionalmente, obtuvimos registros del coatí enano mientras consumía huevos de tortuga marina (n = 1) y desechos orgánicos de origen antrópico (n = 2). Discusión: La evidencia del consumo de frutas aunado al consumo de alimentos de diferente origen apoya la idea de que el coatí enano tiene una dieta omnívora basada principalmente en el consumo de frutas, lo que coincide con información reportada para otras especies del género, como el coatí de nariz blanca (N. narica) y el coatí sudamericano (N. nasua).

Tourist use limits with turtles in Cozumel

The release of sea turtle hatchlings has become an important tourist activity in several beach destinations; however, this activity has generated crowds and inadequate situations that could negatively affect this species and its chances of survival. The objective of this research was to determine the tourism carrying capacity for the release of sea turtle hatchlings in a natural protected area in the island of Cozumel. A multi-criteria method was applied, with data from biological monitoring and a review of current environmental laws and regulations. As a result, the tourism carrying capacity was estimated at 1466 people or 147 groups per season. In addition, four good environmental practices were proposed for tourist guides and tourist services providers. This study will improve the conservation of this ecologically and economically important species, which is endangered worldwide.

Home range and activity patterns of the Critically Endangered endemic pygmy raccoon of Cozumel Island, México

AbstractIndividuals from island and continental mammal populations have shown a number of differences in their behavioral ecology. We predicted that, like other island carnivores exhibiting dwarfism, the pygmy raccoon (Procyon pygmaeus), a Critically Endangered carnivore endemic to Cozumel Island, México, would show differences in its home ranges and activity patterns when compared to its mainland counterpart, the racoon, P. lotor. We radio-tracked 11 individuals (six males, five females) from February to July 2017 and used location data derived from triangulation to estimate the home range size, diel activity patterns, and distances traveled of pygmy raccoons. Individuals showed an average home range size between 96.9 ± 18.8 ha (95% minimum convex polygon) and 123.3 ± 31.2 ha (95% fixed kernel). Home ranges of males (109.4–142.8 ha) were larger than those of females (81.8–99.9 ha). Average home ranges were in the lower extreme of those reported for continental raccoons. Activity patterns of pygmy raccoons generally begin at sunset and continue up to 04:00 with rare activity peaks during the day; there were no significant differences in activity patterns between sexes. Data on spatial needs of individuals, and differences between sexes or insular versus continental populations have implications for conservation planning and management.

Quaternary paleoenvironments based on pedogenic, sedimentary and karstic processes in the coastal geosystems of Cozumel Island, Mexico

The Quaternary carbonatic deposits of the Cozumel Island are mainly reefs and calcarenites in which karstic features, red clayey paleosols and layers of calcretes provide a record of terrestrial paleoenvironments still poorly explored. A main section, Cantera Payo, and three complementary sections: Cantera Transversal, Aerolito and Chempita were studied. Besides field work, micromorphology, physicochemical and mineralogical analyses of soils and calcretes were done. C and O stable isotope analysis was also conducted in calcretes. The cyclicity of sedimentary, karstic and pedogenetic processes was established. The chronological frame was obtained through the correlation dated calcretes and coral samples from Yucatan Peninsula, with ages ranging between ∼Marine Isotope Stage (MIS) 7 to MIS 1. Two paleo-karstic surfaces were identified, labeled as PK1 (older) and PK2 (younger). The PK1 surface showed multi-face karst features as collapse breccias, dissolution pits and pipes, and karstic pockets filled with lithified brown and red paleosols. The red paleosols exhibited abundant redoximorphic features. Clay mineralogy in paleosols and modern soil is similar, with vermiculite and minerals of the kaolinite group. We interpret they are the result of moderate weathering under a seasonal tropical climate like that of present-day conditions. PK1 is capped by a calcrete layer, whose age probably corresponds to the Marine Isotope Stage (MIS) 6 (164 a 135 ka). Therefore, the host rock and the karstification and pedogenetic processes should occur before (probable during MIS 7) The stable carbon isotope composition of this calcrete has a mean δ13C value of −10.40 ‰ that suggests the presence of a C3 plant cover. During the MIS 5, poorly cemented calcarenites accumulated in the island related to the sea level rise during this interglacial stage. This calcarenite level has less developed karstification and pedogenetic processes. Another laminar calcrete with root traces and septal alveolar structure is found on top of the studied sections formed in the MIS 5 and the transition to MIS 4. Its δ13C value ranges between −9.40 ‰ and − 10.27 ‰ also related to a C3 plant cover. In the period between MIS 4 and MIS 1, karst development and pedogenesis is observed on the island, evidenced by the formation of caves and reddish-brown soils.

Population trends and viability of the critically endangered Cozumel Curassow: a 25-year perspective

ABSTRACT The Cozumel Curassow (Crax rubra griscomi) is a critically endangered endemic bird from Cozumel Island, Mexico. After it was believed to be extinct, it was rediscovered in 1994. Its population status was assessed in 1994–1995, and later in 2005, predicting a population decline over the next four decades. A new evaluation of its population size was carried out in 2017 and 2019. Some of the main factors that affect the population size of this cracid were identified with a generalized linear model. With a line transect sampling effort over 360 km, a population size of 499 ± 172 individuals was estimated in the tropical semi-deciduous forest occurring in the island, which was slightly higher compared to previous population evaluations. The distance to water bodies was significantly associated with the population size of the Cozumel Curassow, as well as the abundance of some species of fauna and flora. By modeling various scenarios, population viability was assessed over a period of 100 years, predicting a relatively stable population size with great variability depending on scenarios. However, as estimated in previous studies, given its small population size and continued threats, the Cozumel Curassow continues to be endangered.

Theoretical assessment of the available power from the marine energy sources in Mexico

While the need to use clean, renewable energies in electricity generation is universally understood, Mexico is lagging behind other countries regarding the contribution these sources have to the production of energy nationally. The first hurdle to overcome is providing accurate information for decision-makers and potential investors. In the case of renewable marine energy, this means generating data on the possible installed electrical capacities of the various sources at sites across the country. From this, it is possible to estimate the economic viability of implementing renewable energy projects at specific locations. This work, therefore, aims to characterize the available power from diverse energy sources around the coasts of Mexico and to make recommendations of sites where the energy potential warrants further analysis. A literature review of the power available from marine currents, waves, and thermal and saline gradient sources was performed for the Mexican Caribbean. Several sites were found to be geographically viable; there is sufficient potential energy available to meet at least part of the energy demands of the Yucatan Peninsula and Cozumel Island. Key sites are to the south of Cozumel Island and in the Cozumel Channel for energy harvested from ocean currents. In the northern part of Quintana Roo, sites offer great potential for wave energy, while the central part of the state could be suitable for energy generation from thermal gradients. In Chetumal Bay, there is potential for saline gradient electricity. Wave energy potential was evaluated for the entire Mexican coast, and seven locations are recommended for further investigation. A conservative gross estimation has shown that wave energy could contribute up to 0.2 % of the national demand in the short or mid-term, with a relatively small investment and a low environmental impact.

The microfacies distribution pattern of Cozumel Island in southeastern Mexico: An atoll-like model led by quaternary glacioeustatic sea-level changes

Isolated carbonate banks in stable tectonic settings are ideal for understanding the architecture of sedimentary systems and their response to flooding events. Within these environments, sea-level changes play a primary role in depositing sedimentary units during high sea levels and unconformities during sea-level drops. Microfacies analysis and geologic interpretation, combined with a High Resolution Digital Elevation Model from LiDAR data were used to reevaluate the sediment distribution pattern of Cozumel Island, proposing a new depositional model. The chronostratigraphic framework was established by correlating the exposure surfaces (caliches) of Cozumel with others in adjacent regions. The study of several sections around the island led to the identification of two lithostratigraphic units. Unit 1 comprises two coral reef facies associations (FAs 0 and 1), separated by the Caliche-0 layer. The upper limit of Unit 1 is represented by the Caliche 1 layer and the karst features developed during Marine Isotopic Stage (MIS) 6. Unit 2 was deposited over the ancient karst topography as the lower limit, with Caliche 2 as the upper limit. Unit 2 comprises three facies associations (FAs-2A, B, C), consistent with the protected, open lagoon and the facies of the platform margin, establishing atoll-like depositional conditions. Unit 2 developed during the last interglacial MIS 5e, whereas the Caliche 2 layer started to develop in a post-MIS 5e event during the sea-level drop. This exposed the previous depositional environments to meteoric diagenesis with the formation of the caliche layer. The Caliche 2 layer stabilized the landscape until the present day. Unit 2 correlates to certain morphostratigraphic and geomorphological structures (Terraces I, II, III) on the island. The emplacement of sand islands (FAs-2A), preexisting topography, relative sea-level variations, and sediment supply lead to the pattern and configuration of the depositional model. In addition, the evolution of Cozumel Island during the MIS 5e is similar to other Holocene atoll-like islands in the Caribbean region.

Spatio-Temporal Variation of the Abundance of Pearl Oyster (Pinctada mazatlanica) Spat and Its Relevance in the Location of Suitable Sites for Extensive Pearl Oyster Culture

In general, pearl cultivation has advanced with organisms produced and improved in hatchery; however, wild spat collection is still the primary source for commercial cultivation. In Mexico, progress toward pearl oyster hatchery spat production is yet in the experimental stage. The only three farms established in the country (Guaymas, La Paz, and Cozumel Island) rely on extensive culture. Constant spat supply is imperative to ensure a successful operation; at La Paz Bay, however, larval uptake of the pearl oyster Pinctada mazatlanica in artificial collectors has always been low. This study aimed to assess spatio-temporal and bathymetric patterns of spat distribution across the area to locate suitable sites to install spat collecting stations. Our results showed significant differences (P < 0.05) between stations. Mogote, Caimancito, Punta Colorada, and Gaviota Island were the stations with the highest spat abundance at 1-m depth in July–September after 40 and 60 days of immersion. The data were also analyzed with generalized linear models. The best models, selected with the Akaike and Bayesian criteria, suggest that 1-m depth, 40- and 60-day immersion time, and site (particularly, Caimancito Beach, Punta Colorada, and Gaviota Island) contributed significantly to explaining the highest catches (mean: 5–8 organisms/collector) of P. mazatlanica spat in La Paz Bay. Therefore, the area within these sites should be considered suitable for installing the network of artificial collectors during the season of high spat abundance.