Sustaining small-scale fisheries through a nation-wide Territorial Use Rights in Fisheries system.

Territorial Use rights in Fisheries (TURFs) are used around the world to manage small-scale fisheries and they've shown varying levels of success. Our understanding of what leads to different performance levels is limited due to several reasons. Firstly, these systems are often present in areas with low monitoring capacity where data is scarce. Secondly, past research has centered on the analysis of successful cases, with little attention paid to entire systems. Thirdly, research has been ahistorical, disconnected from the development process of TURF systems. Fourthly, TURFs are often viewed as homogenous ignoring the socio-ecological conditions under which they develop. To address these gaps, the study focuses on Mexico as a case study and context. The research first presents a historical overview of the development of TURF systems in Mexico, including the institutional and legal frameworks that have shaped their evolution. The paper then presents a TURF database that maps all TURF systems in Mexico, including their geographical locations and characteristics. In addition, the study presents case studies based on identified archetypes that showcase the diversity of TURF systems in Mexico, highlighting the different types of systems and the challenges they face. By presenting a comprehensive map of all TURF systems in Mexico, this research paper aims to make an important addition to the case studies in the global literature on TURF systems and provide a valuable resource for marine resource management policymakers, researchers, and practitioners.

Description of first nursery area for a pygmy devil ray species (Mobula munkiana) in the Gulf of California, Mexico.

Munk's pygmy devil rays (Mobula munkiana) are medium-size, zooplanktivorous filter feeding, elasmobranchs characterized by aggregative behavior, low fecundity and delayed reproduction. These traits make them susceptible to targeted and by-catch fisheries and are listed as Vulnerable on the IUCN Red List. Multiple studies have examined fisheries impacts, but nursery areas or foraging neonate and juvenile concentrations have not been examined. This study describes the first nursery area for M. munkiana at Espiritu Santo Archipelago, Mexico. We examined spatial use of a shallow bay during 22 consecutive months in relation to environmental patterns using traditional tagging (n = 95) and acoustic telemetry (n = 7). Neonates and juveniles comprised 84% of tagged individuals and their residency index was significantly greater inside than outside the bay; spending a maximum of 145 consecutive days within the bay. Observations of near-term pregnant females, mating behavior, and neonates indicate an April to June pupping period. Anecdotal photograph review indicated that the nursery area is used by neonates and juveniles across years. These findings confirm, for the first time, the existence of nursery areas for Munk's pygmy devil rays and the potential importance of shallow bays during early life stages for the conservation of this species.

Isotopic (δ15 N) relationship of pregnant females and their embryos: Comparing placental and yolk-sac viviparous elasmobranchs.

Nitrogen stable isotopes ratios (δ15 N) were determined for selected tissues (muscle, liver, blood and yolk) of pregnant females and their embryos of a placental viviparous species, the Pacific sharpnose shark (Rhizoprionodon longurio), and a yolk-sac viviparous species, the speckled guitarfish (Pseudobatos glaucostigmus). The R. longurio embryo tissues were 15 N enriched compared to the same tissues in the pregnant female, using the difference in δ15 N (Δδ15 N) between embryo and adult. Mean Δδ15 N was 2.17‰ in muscle, 4.39‰ in liver and 0.80‰ in blood. For P. glaucostigmus, embryo liver tissue was significantly 15 N enriched in comparison with liver of the pregnant female (Δδ15 N mean = 1.22‰), whereas embryo muscle was 15 N depleted relative to the muscle of the pregnant female (Δδ15 N mean = -1.22‰). Both species presented a significant positive linear relationship between Δδ15 N and embryo total length (LT ). The results indicated that embryos have different Δδ15 N depending on their reproductive strategy, tissue type analysed and embryo LT .

Shark movement patterns in the Mexican Pacific: A conservation and management perspective.

Marine animal tracking has become one of the major tools used to understand the behavior and ecology of a multitude of species in the ocean, thus there is an increasing body of knowledge about this subject worldwide, particularly for sharks. Nevertheless, little was known of the movement patterns of shark in the Mexican Pacific (MXP) and Gulf of California (GOC), except for the pioneering work carried out in the 1980s on the movements of scalloped hammerhead sharks in El Bajo Espiritu Santo and other islands in the region, as well as ongoing studies on white shark movements, migratory patterns and behavior off Isla Guadalupe. Here we present an overview of previous studies on the movements of sharks, as well as a comprehensive description of new studies currently being carried out by our research group at Pelagios Kakunjá on several species of sharks in the MXP. We show how information gleaned from these studies can be put to use to guide sustainable exploitation policies and promote effective conservation practices.