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This dataset comes from a multi-institution compilation of monitoring information for 13 marine herbivorous fishes belonging to six genera of five families: Acanthuridae, Girellidae, Kyphosidae, Pomacentridae and Scaridae, gathered from 2005 to 2020 in the Gulf of California. The database presents a total of 884 records of biomass and density got from 15,542 visual censuses performed using scuba diving in 34 localities comprising 268 rocky and coral reef sites. The censuses consisted of belt transects (250 m2, 100 m2, and 60 m2) laid parallel to the coastline, where expert monitors recorded the abundance of all observed adult individuals of the 13 target herbivorous species, and visually estimated the total length (cm) of each fish. In the database, the information for each transect is presented in the form of average fish density (individuals/m2) and biomass (g/m2), the latter was estimated based on the abundance and size per individual and the published weight-length relationship for each species. Also, we present the latitude and longitude of each locality, type of management, localities in the Gulf of California, institutions, the initial and final year of data, total number of years, as well as the mean, standard deviation, sample size, slope (annual rate of change), probability value, standard error and minimum and maximum value calculated for each species within each locality. This dataset represents an historical baseline of the status of the 13 species in the Gulf of California and can be used to conduct analyses of temporal and spatial trends in herbivorous fish assemblages, considering tropicalization of the interest region due to global change. Moreover, this data will provide key information to stakeholders and managers of protected areas along the gulf and the eastern tropical Pacific region.

The octopus fishery in the state of Yucatan is one of the most important in Mexico and landings have doubled over the past decade causing an increase in the demand for crabs used as bait. Data on bait composition and their harvest are limited even though its economic and ecological impact could be considerable. DNA barcoding of the 16S gene was used to identify the species of crustaceans in 93 samples of bait collected from 12 localities from Yucatan during August to October 2022. A total of nine species of crustaceans were identified, from which the mangrove crab Ueides cordatus was the most frequent (61%), followed by the longnose spider crab (Libinia dubia, 14%), and the Caribbean spiny lobster (Panu/irus argus, 8%). The use of bait shows strong spatial patterns, including the local exploitation of some species and the import of bait from various geographical sources from other adjacent Mexican states to meet the demand. Although some sustainable practices were documented, such as using the discarded cephalotorax from the fishery of Caribbean spiny lobster, at least one species banned as bait by fisheries regulations (the stone crab Menippe mercenaria) was also identified. The American horseshoe crab (Limulus polyphemus), a protected species of national and international conservation concern, was absent in this samples. This study suggests that bait harvest for the octopus fishery could potentially impact both local and distant crab populations, and highlights the need to create and improve existing regulations for bait harvest that need to be built and clearly communicated within the fishing communities to improve the sustainability of the fishery. KEY WORDS: crabs. Octopus maya. Mexico, fishery management, DNA barcoding, INTRODUCTION Mexico is one of the largest producers of octopus in the world, ranking first in America and third globally. During the last 10y, the state of Yucatan has been [...]

Abstract Developing a metapopulation framework contributes to the understanding of spatial processes and structures in populations, providing basic information for conservation biology. However, the extent to which the metapopulation structure differs geographically and across life history stages is unexplored for most fishes. Here, we compared the population structure and connectivity patterns of juvenile yellow snapper Lutjanus argentiventris in mangroves of the Eastern Tropical Pacific Ocean. In both the Gulf of California and Galápagos, these fish experience an array of environmental and oceanographic conditions that produce unique otolith microchemistry signatures and genetic population structures. In the Galápagos Archipelago, we used otolith microchemistry and microsatellite DNA, while for the Gulf of California, we only used otolith microchemistry. We observed relatively small differences in the otolith microchemistry at the ecoregion spatial scale (10–100 km2) for the Galápagos and the Gulf of California (classification accuracy of 57% and 64%, respectively). At the finer mangrove spatial scale (~1 km2), we found larger differences in the otolith microchemistry among the Gulf of California mangroves (classification accuracy ~90%) than in Galápagos (classification accuracy ~24%), potentially related to a stronger environmental gradient in the former. Based on otoliths, 75% of juveniles were migrants among mangroves in the Galápagos, in contrast to only around 10% of juveniles being migrants among the Gulf of California mangroves, suggesting a metapopulation structure characterized by high rates of self‐recruitment for snappers in the Gulf of California. For Galápagos, both otolith microchemistry and genetics supported the presence of a source–sink metapopulation structure for the yellow snapper, with high levels of connectivity in mangroves within the Eastern and Western ecoregions (FST = 0.003, p

Larval genetic information influences populations’ genetic pools, causing genetic homogenization or structuration. So, knowing about adult and larval genetic information is essential to understand processes such as connectivity. The aims are to evaluate Twospot flounder (Bothus robinsi, a fish with a high dispersal potential) larval pools’ genetic diversity, test if the larvae tend to mix or display collective dispersal, compare genetic information between larvae and adults and evaluate its connectivity. We used ddRADSEQ to genotype 1,034 single nucleotide polymorphic sites from B. robinsi larvae sampled in waters from the Bay of Campeche and the eastern Gulf of Mexico (GOM) and adults sampled on Florida’s continental shelf. Larvae were identified morphologically and by DNA barcoding. We estimated Fst-paired comparations, Principal Components Analysis (PCA), Discriminant Analyses of Principal Components (DAPC), and a Structure analysis to understand genetic trends. With the software COLONY, we made a sibship evaluation. We observed no significant heterogeneity among regions (Fst p-values>0.05). PCA, DAPC, and the Structure Analysis showed one genetic cluster, indicating genetic homogeneity. We did not detect full-sibs or half-sibs. We linked the results with the high dispersal potential of B. robinsi due to a long pelagic larval duration and the potential of ocean dynamics to transport and mix larvae from all GOM shelf areas. These findings suggest that the dispersal potential of B. robinsi is large enough to produce genetic connectivity in all GOM subpopulations and that time spent by its larvae in dispersal pathways is enough to mix larvae from different GOM subpopulations, indicating a panmictic population.

Mislabeling of seafood is a global phenomenon that can misrepresent the status and level of consumption of wild fish stocks while concealing the use of many other wild species or those originating from aquaculture and sold as substitutes. We conducted a DNA barcoding study in three cities within Mexico (Mazatlan, Mexico City and Cancun) and sequenced the COI gene in 376 fish samples sold as 48 distinct commercial names at fish markets, grocery stores, and restaurants. Our goal was to identify the main species sold, their mislabeling rates and the species most used as substitutes. Overall, the study-wide mislabeling rate was 30.8% (95% CI 26.4–35.6). Half of the samples collected belonged to five species traded globally (yellowfin tuna, Atlantic salmon, mahi, swai, and tilapia), most of them with important aquaculture or ranching production levels. These species were commonly used as substitutes for other species and showed low mislabeling rates themselves (≤ 11%, except mahi mahi with 39% mislabeling). The other half of the samples revealed nearly 100 species targeted by small-scale fishers in Mexico and sold under 42 distinct commercial names. Popular local commercial names (dorado, marlin, mero, robalo, mojarra, huachinango, pargo, sierra) showed the highest mislabeling rates (36.3% to 94.4%) and served to sell many of the 53 species identified as substitutes in our study. We discuss the observed patterns in relation to landing and import data showing differences in availability of commercial species and the links to explain observed mislabeling rates and the use of a species as a substitute for other species. We also outline some of the implications of establishing a labeling and traceability standard as an alternative to improve transparency in the trade of seafood products in Mexico.

Marine conservation design and fisheries management are increasingly integrating biophysical, socio-economic and governance considerations. Integrative approaches are adopted to achieve more effective, equitable, inclusive, and robust marine policies and practices. This paper describes a participatory process to co-produce biophysical, socio-economic, and governance principles to guide the design and management of marine reserves in three regions of Mexico: the Pacific region of the Baja California Peninsula, the Gulf of California, and the Mexican Caribbean. The process of co-producing the principles included convening a coordination team, reviewing the science, convening multi-stakeholder workshops, developing and communicating the principles with key practitioners and policy makers, and supporting uptake and application to policy and practice. Biophysical principles were related to: habitat representation and risk spreading; protecting critical, special and unique areas; incorporating connectivity; allowing time for recovery; adapting to changes in climate and ocean chemistry; and considering threats and opportunities. Socio-economic principles focused on: integrating the social context, local aspirations, and human-environment interactions; considering economic and non-economic uses, promoting an equitable distribution of costs and benefits, and respecting and maintaining cultural identity and diversity. Governance principles prioritized establishing and ensuring legitimacy and institutional continuity; implementing collaborative and adaptive management; and, promoting effective management. The paper also examines early efforts to implement the principles, next steps to promote further uptake and application in Mexico, and lessons learned from the process. Thus it provides insights into a practical process and a set of principles that are valuable to inform marine conservation and fisheries management processes elsewhere.

Aligning the ecological and social dimensions of the connections present between users that harvest a shared natural resource is a necessary step toward sustainable management. However, contrasting estimates of connectivity across disciplines is a challenging task and few empirical studies have focused on population dynamics within fish species with a complex life history. We used a collaborative approach merging citizen science, population genetics, oceanographic modeling, and interviews to collect empirical connectivity data of individual fish, fishing sites, and fishers. We integrated the data within a multilevel social-ecological network framework describing the interactions between two communities of small-scale fishers (Bahia Kino and Puerto Libertad, Sonora, Mexico) targeting leopard grouper (Mycteroperca rosacea). We identified two types of social-ecological links, including the use of specific fishing sites by individual fishers and the harvest of individual fish by individual fishers. Despite their fishing zones not overlapping, the ecological links between two communities located ~150 km apart were consistent and reciprocal where fishing grounds from each community acted as a source of fish to the other during the larval or juvenile/adult stages, respectively. As a result, fishers from the two communities frequently captured fish that were second-degree relatives. In contrast, the probability of social ties among fishers changed significantly depending on the type of connection and was considerably low for leadership and kinship although some communication was present. Our study highlighted how local actions (e.g., recovery from marine reserves or overfishing) are likely to impact the neighboring community as much as locally. The geographic scale and strength of key ecological process supporting fish stocks through the fish life cycle seem to be larger than those of social connections among fishers. Fishers and managers could benefit from a broader regional perspective that strengthens connections between communities about shared goals and activities. We examine some insights learned on the constraints of connectivity given different attributes of each ecological and social component and methodological challenges identified. We also discuss ways to improve collaborative management between the two communities.

A management approach was developed that combined spatial and non-spatial tools to inform a Coastal and Marine Spatial Planning Process (CMSP) in the Puerto Peñasco-Puerto Lobos Coastal Corridor, Northern Gulf of California, Sonora, Mexico. Four fisheries management tools were applied with an emphasis on ecosystem level management for eleven small-scale fisheries. Two spatial management tools, using a spatial prioritization approach, were combined with a permit regularization process, a non-spatial quota prioritization, and a tradeoff analysis in a novel way:• Locally Managed Marine Areas were developed, these are spatial areas where individual community fishermen are assigned the rights to harvest and manage specific fisheries within defined geographic areas.• Fishery refuges that incorporate information on fisheries, ecological importance, and connectivity.• A non-spatial quota prioritization process using a framework for the integrated assessment of stocks, encompassing a vulnerability analysis, a sustainability analysis, and a management framework analysis.• A trade-off analysis of the combination of these different management tools, using an Atlantis ecosystem model for the northern Gulf of California, that tested the ecosystem effects of alternative scenarios to assess benefits in support of ecosystem-based management.

Twelve microsatellite loci were isolated from an enriched genomic library of the rock scallop (Spondylus calcifer). One locus was monomorphic. Overall polymorphic loci, the mean numbers of alleles per locus at one locality was 9.6 (range 3–16), and the average observed and expected heterozygosities were 0.650 and 0.707, respectively. Three loci deviated from Hardy–Weinberg equilibrium, and from these, one locus had and excess of heterozygotes and the other two loci showed deficits of heterozygotes likely due to the presence of null alleles. No evidence of linkage disequilibrium was found among loci. These loci are the first microsatellites ever reported for the monotypic family Spondylidae, and will be useful to validate the predictions of oceanographic larval transport models and connectivity between patchy reefs within fishing areas and marine reserves in the northern Gulf of California, Mexico.

Twelve microsatellite markers (six di-nucleotides, four tri-nucleotides and two tetra-nucleotides) were isolated and characterized for Callinectes bellicosus, a commercial crustacean species from the Gulf of California, Mexico. One locus was monomorphic and 11 loci were polymorphic in 32 individual samples from a single location. Overall polymorphic loci, the number of alleles per locus ranged from 2 to 24 (average 10.0), the observed heterozygosity ranged from 0.094 to 0.969 (average 0.603), and the expected heterozygosity varied from 0.089 to 0.935 (average 0.597). One locus deviated significantly from Hardy–Weinberg equilibrium due to an excess of heterozygotes, while another locus showed evidence for the presence of a null allele. No evidence of linkage disequilibrium was found among pair of loci. These markers will be helpful to estimate the level of genetic connectivity over a small spatial and temporal scale in order to identify stocks for the management of this small-scale fishery in the Gulf of California.

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The Gulf of California (GC) is a semi-closed sea in the Tropical Eastern Pacific and is recognised as a highly diverse marine ecosystem. Despite this status, this region is still poorly studied in comparison to other marine hotspots. To start filling this gap, we attempt to provide a global overview of reef-fish diversity around the numerous islands of the region. We evaluated species richness, the abundance and biomass, and the functional diversity of the fish assemblages for the major islands of the GC. We first highlight that the southwestern part of the central GC is the hotspot of reef-fishes diversity within the GC, in terms of species richness, functional diversity, and fish abundance. We then found out an important functional divergence between fish assemblages of northern and southern regions. The fish biomass of each region is dominated by different species, characterised by different ecological traits (the opposite of functional convergence). This functional divergence may be explained by an important oceanographic heterogeneity along the latitudinal axis of the GC. The northern part shows larger climate fluctuations while the southern part is more tropical and climatically stable. Such functional divergence is a biodiversity facet to take into account when determining the sites to focus conservation action. In the GC, this criterion allows the importance of some sites to be highlighted to preserve the legacy of the reef-fishes, despite their lower diversity levels. Keywords: Biodiversity, Biologically important area, Functional traits, Marine protected area, Sea of Cortez, Tropical Eastern Pacific

The fishery for octopus in Northwest Mexico has increased to over 2,000 tons annually, but to date the specific composition of the catch has been ignored. With at least three main species targeted by artisanal fisheries in the region with distinct life histories, the lack of basic biological information about the distribution, metapopulation size and structure of each species could impede effective fisheries management to avoid overexploitation. We tested if different life histories of three species of octopus could help predict observed patterns of genetic diversity, population dynamics, structure and connectivity and how this information could be relevant to the sustainable management of the fishery. We sequenced two mitochondrial genes and genotyped seven nuclear microsatellite loci to identify the distribution of each species in 20 locations from the Gulf of California and the west coast of the Baja California peninsula. We tested five hypotheses derived from population genetic theory based on differences in the fecundity and dispersal potential for each species. We discovered that Octopus bimaculoides with low fecundity and direct development (without a planktonic phase) had lower average effective population size and genetic diversity, but higher levels of kinship, population structure, and richness of private alleles, than the other two species. These features indicated limited dispersal and high local recruitment. In contrast, O. bimaculatus and O. hubbsorum with higher fecundity and planktonic phase as paralarvae had higher effective population size and genetic diversity, and overall lower kinship and population structure than O. bimaculoides. These observations supported higher levels of gene flow over a larger geographical scale. O. bimaculatus with the longest planktonic paralarval duration and therefore larger dispersal potential had differences in the calculated parameters possibly associated with increased connectivity. We propose O. bimaculoides is more susceptible to over exploitation of small, isolated populations and could have longer recovery times than the other two species. This species may benefit from distinct fishery management within each local population. O. bimaculatus and O. hubbsorum may benefit from fishery management that takes into account metapopulation structure over larger geographic scales and the directionality and magnitude of larval dispersal driven by ocean currents and population connectivity among individuals of each locality. The distribution of each species and variations in their reproductive phenology is also important to consider when establishing marine reserves or seasonal fishing closures.

ABSTRACT Members of the bivalve molluscan family Spondylidae were very important elements in the world view of preHispanic cultures of America, and today remain as symbols of culture heritage in [...]