Marine reserves help preserve genetic diversity after impacts derived from climate variability: Lessons from the pink abalone in Baja California

Genetic diversity is crucial for the adaptation of exploited species like the pink abalone (Haliotis corrugata), faced with threats from climate change, overfishing and impacts associated with aquaculture production. While marine reserves are commonly used to mitigate risks to marine populations, the duration, size, location and larval connectivity needed for a reserve to help conserve genetic resources is still poorly understood. Here, we examine the effects of fishing, reserves, and restocking on the genetic diversity of 10 populations from central Baja California, Mexico, and Southern California, USA. We demonstrate that each population shows characteristic genetic signatures according to recent management decisions. We found high allelic diversity, particularly rare alleles, a larger effective population size and a lack of a recent genetic bottleneck in pink abalones within a small (0.8 km2), recently established (5 years) reserve in Baja California, compared to other fished sites after a climatic bottleneck. Higher diversity may result from the presence of older animals in the reserve. Due to its location, the reserve may also act as an important hub connecting distant populations via larval dispersal. In contrast, a population from California showed genetic isolation, loss of allelic diversity and high relatedness, consistent with the collapse of fisheries in the 1990s and their lack of recovery thereafter. In addition, a fished area in Baja California with a history of restocking for over a decade showed an increase in frequency of related individuals and high genetic differentiation from nearby sites that were consistent with the production of larvae from a few adults in the laboratory. A network of strategically placed small marine reserves that considers ocean circulation patterns could help to maintain genetic diversity and connectivity of exploited populations

Marine reserves can mitigate and promote adaptation to climate change

Strong decreases in greenhouse gas emissions are required to meet the reduction trajectory resolved within the 2015 Paris Agreement. However, even these decreases will not avert serious stress and damage to life on Earth, and additional steps are needed to boost the resilience of ecosystems, safeguard their wildlife, and protect their capacity to supply vital goods and services. We discuss how well-managed marine reserves may help marine ecosystems and people adapt to five prominent impacts of climate change: acidification, sea-level rise, intensification of storms, shifts in species distribution, and decreased productivity and oxygen availability, as well as their cumulative effects. We explore the role of managed ecosystems in mitigating climate change by promoting carbon sequestration and storage and by buffering against uncertainty in management, environmental fluctuations, directional change, and extreme events. We highlight both strengths and limitations and conclude that marine reserves are a viable low-tech, cost-effective adaptation strategy that would yield multiple cobenefits from local to global scales, improving the outlook for the environment and people into the future

The Historical Ecology of Abalone (Haliotis Corrugata and Fulgens) in the Mexican Pacific

Abalone shells and meat played and play an important role in the rich economic, social y cultural history of Baja California. Chinese and Japanese fishermen and later the consolidation of Mexican cooperatives have all fished in this region. Information obtained through surveys and oral history from three generations of abalone divers on Baja California has revealed that over time catches have decreased and the organisms fished have reduced their size. The decrease in catch size and weight described by the divers generate an approximate 70% reduction in abalone’s reproductive capacity. Resumen:Conchas y carne de abulón desempeñaron y desempeñan un rol importante en la rica historia económica, social y cultural de Baja California, México. En la región pasaron desde pescadores chinos, japoneses hasta la consolidación de cooperativas mexicanas. Información obtenida a través de entrevistas, reportes históricos e historia oral de tres generaciones de buzos de abulón revela la reducción tanto en capturas como en tamaño del organismo. Esta reducción genera una disminución aproximada del 70% en la capacidad reproductiva de este molusco

Do marine reserves increase prey for California sea lions and Pacific harbor seals?

Community marine reserves are geographical areas closed to fishing activities, implemented and enforced by the same fishermen that fish around them. Their main objective is to recover commercial stocks of fish and invertebrates. While marine reserves have proven successful in many parts of the world, their success near important marine predator colonies, such as the California sea lion (Zalophus californianus) and the Pacific harbor seal (Phoca vitulina richardii), is yet to be analyzed. In response to the concerns expressed by local fishermen about the impact of the presence of pinnipeds on their communities' marine reserves, we conducted underwater surveys around four islands in the Pacific west of the Baja California Peninsula: two without reserves (Todos Santos and San Roque); one with a recently established reserve (San Jeronimo); and, a fourth with reserves established eight years ago (Natividad). All these islands are subject to similar rates of exploitation by fishing cooperatives with exclusive rights. We estimated fish biomass and biodiversity in the seas around the islands, applying filters for potential California sea lion and harbor seal prey using known species from the literature. Generalized linear mixed models revealed that the age of the reserve has a significant positive effect on fish biomass, while the site (inside or outside of the reserve) did not, with a similar result found for the biomass of the prey of the California sea lion. Fish biodiversity was also higher around Natividad Island, while invertebrate biodiversity was higher around San Roque. These findings indicate that marine reserves increase overall fish diversity and biomass, despite the presence of top predators, even increasing the numbers of their potential prey. Community marine reserves may help to improve the resilience of marine mammals to climate-driven phenomena and maintain a healthy marine ecosystem for the benefit of both pinnipeds and fishermen

Marine reserves can mitigate and promote adaptation to climate change.

Strong decreases in greenhouse gas emissions are required to meet the reduction trajectory resolved within the 2015 Paris Agreement. However, even these decreases will not avert serious stress and damage to life on Earth, and additional steps are needed to boost the resilience of ecosystems, safeguard their wildlife, and protect their capacity to supply vital goods and services. We discuss how well-managed marine reserves may help marine ecosystems and people adapt to five prominent impacts of climate change: acidification, sea-level rise, intensification of storms, shifts in species distribution, and decreased productivity and oxygen availability, as well as their cumulative effects. We explore the role of managed ecosystems in mitigating climate change by promoting carbon sequestration and storage and by buffering against uncertainty in management, environmental fluctuations, directional change, and extreme events. We highlight both strengths and limitations and conclude that marine reserves are a viable low-tech, cost-effective adaptation strategy that would yield multiple cobenefits from local to global scales, improving the outlook for the environment and people into the future

A system-wide approach to supporting improvements in seafood production practices and outcomes

Environmental certification and consumer awareness programs are designed to create market incentives for implementing fisheries and aquaculture practices that are more sustainable. Typically focused on particular species and activities, such programs have so far triggered few changes to improve seafood sustainability. Here, we present a conceptual, system-wide fisheries and aquaculture certification program designed to recognize and promote change toward more sustainable and resilient seafood production systems. In contrast to previous efforts, this program concentrates on both ecosystems and various human stakeholders, relies on an adaptive management approach (termed "continual improvement") to enhance outcomes, and considers socioeconomic factors. The goal of this program is to support the restoration and maintenance of healthy ecosystem states and thriving human communities as well as the improvement of whole social-ecological systems

TIII - Arquitectura y Entorno - AR307 - 202101

Descripción: El curso TIII - Arquitectura y Entorno, es un curso de especialidad en la carrera de Arquitectura; parte del estudio del patrimonio edificado y la ciudad histórica, y propone el adiestramiento en el diseño arquitectónico a partir de la transformación y/o reciclaje de un objeto arquitectónico preexistente, y/o la propuesta de edificaciones nuevas relacionadas con el espacio urbano, desde un enfoque contemporáneo. Propósito: El TIII - Arquitectura y Entorno busca que el futuro arquitecto tome conciencia que todo proyecto arquitectónico está destinado a relacionarse con el contexto urbano. A través de la identificación y el análisis, el alumno adquiere las herramientas para diseñar respondiendo al entorno. El curso contribuye directamente al desarrollo de las competencias generales de Ciudadanía y Pensamiento Innovador y la competencia específica de Diseño Fundamentado (que corresponde a los criterios NAAB: PC2, PC3, PC5, PC8, SC3, SC5). Tiene como requisitos: Dibujo Arquitectónico (AR286) y TII - Arquitectura y Arte (AR306)