Temporal trend data (2005-2020) in density and biomass of 13 herbivorous fishes in the Gulf of California.

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.

Marine diversity in the biosphere reserve of the most oceanic island in the Gulf of California: San Pedro Mártir.

San Pedro Mártir island is of high biological, ecological, and fishery importance and was declared a biosphere reserve in 2002. This island is the most oceanic in the Gulf of California, and information on its rocky reefs is scarce. The present study aimed to generate the first list of conspicuous invertebrate and fish species based on in situ observations and to examine the community structure of the shallow rocky reefs of the reserve. In addition, we estimated the ecological indicators of richness, abundance, Shannon diversity, and Pielou evenness to evaluate the conservation status of the biosphere reserve. Data were collected annually from 2007 to 2017 through 2,192 underwater SCUBA transects. A total of 35 species of invertebrates and 73 species of fish were recorded. Most of the species are widely distributed along the eastern Pacific. Overall, 64% of the species found in this study are commercially important, and 11 species have been listed as protected. The abundance of commercially important invertebrate species (i.e., the sea cucumber Isostichopusfuscus and the spiny oyster Spondyluslimbatus) is decreasing, while commercially important fish species have maintained their abundance with periods of increase. The ecological indicators and the abundance and size of the commercial species indicate that the reserve is in good condition while meeting its conservation objectives.

Fisheries management tools to support coastal and marine spatial planning: A case study from the Northern Gulf of California, Mexico.

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.