Short-term effects of community-based marine reserves on green abalone, as revealed by population studies.

Marine reserves (MRs) are implemented worldwide to protect, restore, and manage marine ecosystems and species. However, it is important to document the positive effects those marine reserves have on slow-growth, temperate invertebrates such as abalone. Abalone, Haliotis spp., are marine gastropods of high economic value extracted worldwide for decades, which has led to fisheries-driven population decreases. In this work, we focused on a case study and assessed the short-term (1-2 years) effects of marine reserves established and managed by a local fishing cooperative at Guadalupe Island, Mexico. We evaluated the population status of green abalone, H. fulgens, by conducting (1) an assessment of the green abalone population around Guadalupe Island through subtidal monitoring and (2) an evaluation of the effect of two recently established marine reserves on population parameters such as the increase in density (individuals·m2), biomass, number of aggregated abalone, egg production, and proportion of individuals bigger than 150 mm (minimum harvest size) compared to fished areas. To assess the population around Guadalupe Island, we surveyed 11,160 m2 during 2020 and 2021. We recorded 2327 green abalones with a mean ± SE shell length of 135.978 ± 0.83 mm and a mean density of 0.21 ± 0.02 individuals·m2. All variables were statistically higher at the MRs except for shell length in 2021. In this work, we report for the first time the green abalone population status at Guadalupe Island and a positive short-term biological response to community-based marine reserves. This study suggests that a network of MRs combined with good management could help abalone populations in the short term in Guadalupe Island, potentially leading to more sustainable fishing practices and social-ecological resilience.

Células madre en odontología / Stem cells in dentistry

En la actualidad los procedimientos restaurativos en odontología presentan una gran demanda por parte de los pacientes. Estos procedimientos, que buscan restaurar estructuras perdidas por distintas causas, tienen diferentes enfoques y pueden ser realizados de muchas maneras. La era moderna ofrece un enfoque novedoso que permite la restauración de tejidos y estructuras perdidas mediante el uso de la ingeniería de tejidos. Este novedoso sistema permite, desde distintas áreas, como la terapia con células madre, la biología molecular y la biología celular, que los tejidos dañados o perdidos sean reparados o reemplazados usando tejidos naturales del mismo paciente, lo que representa numerosos beneficios. El objetivo de este trabajo es hacer una revisión de la literatura sobre la ingeniería de tejidos para poder conocer más a fondo sus beneficios y usos en el área odontológica.

Currently, restorative procedures in dentistry are in high demand by patients. These procedures, which are intended to restore missing structures due to multiple causes, have different approaches and can be carried out in many ways. Currently an innovative approach is available that allows the restoration of missing tissues and structures through the use of tissue engineering. By grouping diverse areas, such as stem cell therapy, molecular biology and cellular biology, this science allows that missing or damaged tissues can be restored o replaced using natural tissues extracted from the same patient, which represent numerous benefits. The objective of this paper is to review the literature on tissue engineering in order to better understand its benefits and uses in the dental field.

Ecological risk assessment of PCBs and other organic contaminant residues in Laguna de Terminos, Mexico.

Laguna de Terminos, a wide coastal lagoon system in Campeche, Mexico, was investigated for the contamination by polychlorobiphenyls (PCBs). Distribution of these industrial chemical contaminants along with pesticide residues in the lagoon, as well as their sediment-water partitioning and bioaccumulation by oysters and fish were assessed. Contaminant concentrations in the lagoon were compared with toxicity data for aquatic organisms and the ecotoxicological risks discussed. Current contaminant concentrations generally were several orders of magnitude below acute toxic levels for the most sensitive aquatic species and this seems compatible with the status of nature reserve and functions aimed at Laguna de Terminos. In particular, Penaeidae shrimp species that are the most valuable fisheries resources of Campeche with important populations in the Laguna are not impaired with the current low levels of these contaminants. Nevertheless, due to known environmental persistence, the surveillance of chlorinated contaminant levels in the lagoon ecosystems is recommended.

Pesticide and PCB residues in the aquatic ecosystems of Laguna de Terminos, a protected area of the coast of Campeche, Mexico.

The coastal lagoon system of Laguna de Terminos, Campeche, Mexico, a natural reserve since 1994, was investigated for contamination by agricultural and industrial chemical residues. Water, sediment and biota samples were analyzed for a wide variety of organochlorine and organophosphorus compounds. Chlorpyrifos was detected in water in concentrations up to 72 pgL(-1) and, amongst organochlorine compounds, summation operator PCB were measured averaging 1177 pgL(-1) and summation operator DDT 279 pgL(-1). Residues of chlorinated compounds were present in sediments and in biota with summation operator DDT averaging 190 pg g(-1) and 5876 pg g(-1) in sediment and oysters, respectively. Results show that the more widespread contaminants in the Laguna were residues of chlorinated hydrocarbons, such as DDTs, PCBs, endosulfan, and lindane. Concentrations of residues were not at an alarming level and were even lower than reported for other costal lagoons of the region. Still there is a need to implement control measures on persistent and bioaccumulative compounds that may reach the aquatic system of Laguna de Terminos.