Papers by Francisco Arreguin-Sanchez
Crecimiento y eficiencia alimentaria de la mojarra Cichlasoma heterospilum (Cichlidae: Perciformes) al sur del Golfo de México
Revista De Biologia Tropical, Sep 1, 1997
Cichlasonza heterospilurn, a potentially important species for aquaculture was studied in the sou... more Cichlasonza heterospilurn, a potentially important species for aquaculture was studied in the southern Gulf of Mexico. The sex ratio was 1:1, and there were seasonal differences in abundance of mature individuals. Parameters of the von Bertalanffy growth equation were K = 0.38 (year 1 ), 26 cm (TL), W∞ = 321 g, to = 0.249 years. This omnivore has a daily food consumption per .unit biomass of Q/B = 4.05% of body weight, annual Q/B = 14.8%; however, gross efficiency of growth associated to food consumption can be assumed to be relatively low ( = 0.1147) compared to other commercially important species. Aquaculture would require an increase in growth efficiency.
Turkish Journal of Fisheries and Aquatic Sciences, Jul 1, 2017
Opisthonema libertate (Pacific thread herring) and Cetengraulis mysticetus (Pacific anchovy) are ... more Opisthonema libertate (Pacific thread herring) and Cetengraulis mysticetus (Pacific anchovy) are the two most important herring stocks exploited in the southeastern Gulf of California (SGC). The certification of these stocks is currently planned for achieving sustainable fisheries. This study analysed the role of these two species in the structure, organization and functioning of the ecosystem in this region. Twenty-four indicators of the ecosystem's structure and its organization were obtained based on the output of an Ecopath model of the SGC. The relationships of the functional groups with the ecosystem's indicators were identified using multivariate statistical techniques, and the results indicated similar roles for the Pacific thread herring and the Pacific anchovy in the ecosystem of the SGC. Both species make large contributions to the maintenance of the ecosystem's order (i.e., its structure and organization). These results are directly related to one of the criteria that are evaluated by the Marine Stewardship Council's certification process. Defining the remaining biomass level at sea after fishing would guarantee the sustainability of fisheries in the ecosystem.
The use of stable isotopes and mixing models to determine the feeding habits of soft-bottom fishes in the southern Gulf of California
CBM - Cahiers de Biologie Marine, 2015
Recently, stable-isotope analyses have been coupled with mixing models to determine trophic relat... more Recently, stable-isotope analyses have been coupled with mixing models to determine trophic relationships by identifying the most important types of prey and assessing their relative contribution to the diet. This method has advantages over stomach-content analysis and is emerging as a powerful tool to determine trophic relationships. We analysed the stable-isotope ratios of 15N and carbon 13C in the muscle tissue of 19 soft-bottom fish species found in shrimp- fishing bycatch along the coast of Nayarit, Mexico. An elemental analyser was used, connected to an isotope-ratio mass spectrometer. We processed the isotope data with a Bayesian mixing models using SIAR model. We identified five trophic guilds (crustacean eaters, fish eaters, molluscs eaters, echinoderms eaters and crustacean-fish eaters) based on their principal prey types. Crustacean consumers were the dominant group. The calculated trophic levels of the five guilds ranged from 3.1 to 4.8. Stable-isotope analyses coupled w...
It is now clear that research addressed at a large scale can allow for new insights on complex ph... more It is now clear that research addressed at a large scale can allow for new insights on complex phenomena taking place in the global ocean. Ecological studies are more and more based on data-driven methodologies that rely on pre-existing datasets. However, open-access, digital and cross-disciplinary datasets are still uncommon for ecology. In the face of the global overexploitation of marine resources and rapid degradation of ecosystem integrity, new research tools are required to tackle these issues and enable new powerful, interdisciplinary research capabilities. We have, in fisheries research generally, and at the Fisheries Centre in particular, broad experience with fisheries data collection, and analysis of food web aspects of ecosystem dynamics. With this report titled EcoBase: a repository solution to gather and communicate information from EwE models, Colleter and colleagues have made a big effort at collecting information from all existing ecosystem models worldwide, built u...
CICIMAR Oceánides, 2012
We tested the hypothesis that ecosystem metabolism follows a quarter power scaling relation, anal... more We tested the hypothesis that ecosystem metabolism follows a quarter power scaling relation, analogous to organisms. Logarithm of Biomass/Production (B/P) to Trophic Level (TL) relationship was estimated to 98 trophic models of aquatic ecosystems. A normal distribution of the slopes gives a modal value of 0.64, which was significantly different of the theoretical value of 0.75 (p0.05). We also tested for error in both variables, Log (B/P) and TL, through a Reduced Major Axis regression with similar results, with a modal value of 0.756 (p>0.05). We also explored a geographic distribution showing no significant relation (p>0.05) to latitude and between different regions of the world. We conclude that: a) ecosystem metabolism follows the quarter-power scaling rule; b) transfer efficiency between TL plays a relevant role characterizing local attributes to ecosystem metabolism; and c) there is neither latitudinal nor geographic differences. These findings confirm the existence of a...
Indicadores De Sustentabilidad y Pesca: Casos en Baja California Sur, Mexico
"En este trabajo se realiza un analisis acerca de la relacion entre la sustentabilidad y la ... more "En este trabajo se realiza un analisis acerca de la relacion entre la sustentabilidad y la pesca a traves de indicadores elaborados para el Estado de Baja California Sur en esta actividad extractiva. El trabajo aborda referencias internacionales sobre el concepto de sustentabilidad, asi como la construccion de indicadores para expresar este concepto considerando distintas dimensiones como la ecologica, economica, social e institucional de gobierno. Asi mismo se aborda el estudio de pesquerias de Baja California Sur a traves de la informacion acerca de tendencias de captura y Nivel Trofico Medio de la Captura (NTMC). Lo anterior ilustra el grado de avance o limitaciones que se tienen para cada caso y a partir de esta evaluacion preliminar se sugieren posibles caminos para fortalecer el uso de indices que ayuden a seguir el desempeno de las pesquerias y su nivel de permanencia en el tiempo o de su sustentabilidad. A partir del enfoque propuesto en este trabajo, con la informacion recabada en las distintas dimensiones (Economica, Ecologica, Social y Gobierno) propuestas por FAO (2000) sera menester ampliar el analisis de sustentabilidad, transformando esta informacion en datos cuantitativos que permitan su “ordenamiento espacial” mediante tecnicas estadisticas, para representar cada caso de pesqueria tratado en este analisis, en una figura “isometrica” que permita una rapida, mas facil y comprehensiva identificacion del status de sustentabilidad que presenta el uso de determinado recurso pesquero en Baja California Sur en particular y en otras latitudes en general. Con respecto al estado de salud de los recursos pesqueros del estado de Baja California Sur, el indice de captura IC y el NTMC sugieren una estabilidad de las pesquerias y en consecuencia es de suponerse que tambien en el ecosistema. Esta base de referencia, en lo general, permite suponer un marco de referencia adecuado para planificar desde ahora un desarrollo sustentable de la pesca."
The trophic network of the southern Sinaloa benthonic ecosystem was reconstructed for the period ... more The trophic network of the southern Sinaloa benthonic ecosystem was reconstructed for the period 1994– 1997, using Ecopath with Ecosim version 5.1. The ecosystem is a resource for finfish and shrimp fisheries. The majority of the 37 functional groups were determined from the makeup of captures taken by commercial trawls similar to those used by the shrimp fishery. Incidental captures represented approximately 91% of the total and consisted mainly of fish from the families Sciaenidae, Haemulidae, and Serranidae, followed by macrocrustaceans (Portunidae) and invertebrates (Echinodermata). The trophic model obtained had a pedigree index of 0.57, which represents an acceptable quality from the data used. The ecosystem is represented by 4 discreet trophic levels; medium-level carnivores, including Pleuronectiformes, birds, Sciaenidae, Serranidae, and Centropomidae, contribute the majority of energy transfer in the third level. The mixed trophic impacts show that detritus positively affec...
The monterey sardine (Sardinops sagax) fishery of the Gulf of California was examined between 197... more The monterey sardine (Sardinops sagax) fishery of the Gulf of California was examined between 1972 and 1990. By analysing commercial catch-per-effort-unit data, we determined the density-dependence function of the Catchability coefficient to establish a potential relationship between this coefficient and relative population sizes. These were calculated by two methods, a new catchability deterministic method (CDM) and virtual population analysis (VPA). The inverse rclationship betwcen the catchability cocrficienl and fish density reponed for other purse seine fisheries is presented for the monterrey sardine fishery as well. The curves for both methods were similar, although the abundance determined for APV decreased after 1988/89 and for CDM decreased after 1986/87. Fishing mortality and abundance were determined for each class of length per season
Ciencias Marinas, 1993
Estimates of fishing mortality were obtained for the spotted sea trout Cynoscion nebulosus, which... more Estimates of fishing mortality were obtained for the spotted sea trout Cynoscion nebulosus, which is exploited around Holbox Island off the northeast coast of Yucatán. Fishing mortality as a function of length follows the same pattern for the period of 1983 to 1985, showing a tendency to increase with size. Biomass estimates of the average population vary between 47 to 146 tonnes, probably due to differences in accessibility to the stock between years. The weighted average values of fishing mortality (F) and exploitation rate (F/Z) for the whole population vary within the range 0.358 ≤ F ≤ 0.528 and 0.416 ≤ E ≤ 0.512. Consequences of changes in the length at first capture and catch rate are discussed; however, because C. nebulosus is obtained from a multispecies fishery, non-target species should be considered for management purposes.
Ciencias Marinas, 1991
Stock assessment of the brown shrimp (Penaeus azteca) from the northwest Gulf of Mexico is develo... more Stock assessment of the brown shrimp (Penaeus azteca) from the northwest Gulf of Mexico is developed using monthly data from commercial catches from 1974 to 1982. Growth parameters from the von Bertalanffy equation were as follows: Kmin = 0.142 m–1 to Kmax = 0.1812 m–1; L∞min = 214 mm to L∞max = 236 mm. Mortality rates were obtained directly from the identified cohorts through the catch curve and the weighted average of the amount of fishing applied on each cohort; results were as follows: total mortality, Zmin(1981) = 0.8494 to Zmax(1974) = 1.240; fishing mortality, Fmin( 1981) = 0.3786 to Fmax(1974) = 0.646; and natural mortality, Mmin(1978) = 0.415 to Mmax(1974) = 0.594. Catchability estimations mere: qmin(1975) = 0.0012 to qmax(1978) = 0.0021. Exploitation rate indicates a reduction of 30% of the fishing intensity, for the last two years, compared with the previous ones. From these years (1981 and 1982), fishery was acting under the maximum sustainable yield level.
Latin American Journal of Aquatic Research, 2018
The shrimp trawl fishery in the southeastern Gulf of California is one of the most important in M... more The shrimp trawl fishery in the southeastern Gulf of California is one of the most important in Mexico due to the high economic value of the resource in the national and international market. The management of this fishery is based on permits, a no-trawling zone, a no-fishing season and regulations of fishing gears. In order to analyze the efficiency of the no-fishing season and the viability of a spatial closure, we analyzed the distribution and size structure of four species targeted by the commercial fishery during the 2005-2006 shrimpfishing season, the white shrimp (Penaeus vannamei), blue shrimp (P. stylirostris), brown shrimp (P. californiensis) and crystal shrimp (P. brevirostris). We found that the size distribution of four shrimp species was wide and with variable frequency during the fishing season. The average biomass for each species was different throughout the fishing season, and the white and brown shrimps were the most abundant species. However, the spatial distribution of the biomass was similar for the four species. Our results suggest that the nofishing season is more effective for brown shrimp because the individuals caught by the fishing gear have already reproduced at least once.
Boletín de la Sociedad Geológica Mexicana, 2009
Los estudios geoquímicos y sedimentológicos realizados para evaluar el efecto de la pesca de arra... more Los estudios geoquímicos y sedimentológicos realizados para evaluar el efecto de la pesca de arrastre de fondo en México, son prácticamente inexistentes. En el presente trabajo se contrastan sitios de arrastre y no arrastre de la pesca del camarón en la costa de Sinaloa-Sonora. El análisis del tamaño de grano medio indicó diferencias estadísticamente significativas entre sitios de arrastre y no arrastre. Sorprendentemente, las variables geoquímicas (carbonato de calcio, carbono y nitrógeno orgánico, la razón C/N y los isótopos estables de carbono y nitrógeno) en ambas áreas (prístinas e impactadas), no fueron estadísticamente diferentes. Nuestros datos sugieren que el transporte de materiales y energía regularían, de manera similar en ambas zonas, los procesos biogeoquímicos que determinan los intervalos de estas variables y que no las hace estadísticamente diferentes.
Ciencias Marinas, 1991
El objetivo principal del presente trabajo fue definir un diseño de muestreo óptimo usando técnic... more El objetivo principal del presente trabajo fue definir un diseño de muestreo óptimo usando técnicas de muestreo probabilistico para la obtención de estimaciones del peso promedio por pez, número total de individuos, proporción y número de individuos por clase de longitud en la captura comercial, y sus respectivas varianzas. Se proponeun diseño de muestreo en dos estratos de puertos (oriente y poniente), definidos por la diferencia de tallas de los peces. Para cada estrato, se propone un diseño de muestreo en tres etapas, donde las unidades primarias son los puertos, unidades secundarias las embarcaciones y las unidades terciarias los peces, donde, para cada etapa se obtendrá una muestra aleatoria. Definidos los estimadores, se obtienen expresiones para las varianzas a traves del metodo delta. Por último, fijando un tamaño de muestra para los puertos se obtiene un tamaño de muestra óptimo para unidades secundarias y terciarias a través del método grafito propuesto por Chester y Waters (1985).
Ciencias Marinas, 1993
An analysis was made of the seasonal changes of abundance of the brown shrimp (Penaeus azfecus) p... more An analysis was made of the seasonal changes of abundance of the brown shrimp (Penaeus azfecus) population in the northwestern Gulf of Mexico, related to environmental parameters such as rainfall and fishing effort. Using monthly age-class abundance data (given as catch per unit effort) for the period 1974 to 1982, a principal components analysis was applied and two population indexes were obtained: recruitment strength (as a monthly class strength) and adult density (Solana-Sansores et al., 1989) which is inversely proportional to the log of their actual abundance. Both indexes and the records of environmental parameters were analysed using the multivariate method of canonical correlation. The first canonical correlation was highly significant (P < 0.01) and includes mainly fishing effort and the recruitment strength index. The second one showed a high correlation between rainfall and the adult index. The results show how some environmental factors help to explain the fluctuatio...
Ciencias Marinas, 2000
The pink shrimp, Farfantepenaeus duorarum, fishery of Campeche Bank, Mexico, was analyzed in orde... more The pink shrimp, Farfantepenaeus duorarum, fishery of Campeche Bank, Mexico, was analyzed in order to characterize it and to test the effect of different fishing intensities upon the stock. Catch data consisted of the number of shrimp per commercial class for the 1986–1993 period. A virtual population analysis structured by age was applied to determine seasonal recruitment and fishing mortality patterns with respect to age, as well as the stock-recruitment relationship. With these results, an age-structured deterministic simulation model was developed, which diagnosed the fishery and defined the effects of different exploitation scenarios by considering changes in fishing mortality. Results show that the decreasing catch tendency through the period of analysis is related to recruitment failures. The analysis indicated that a way to mitigate the low recruitment problem is to control and reduce fishing mortality, but stock density will continue to decrease if the current fishing inten...
Ciencias Marinas, 1999
Gillnet selectivity for Lutjanus guttatus and L. argentiventris in Navidad Bay, Jalisco (Mexico),... more Gillnet selectivity for Lutjanus guttatus and L. argentiventris in Navidad Bay, Jalisco (Mexico), was estimated using monthly samples. Gillnets of 7.62- and 8.89-cm mesh size were used for the experimental design; 475 organisms of L. guttatus and 134 organisms of L. argentiventris were caught. The results show that the organisms caught with the 8.89-cm mesh were on average 4 cm larger and 100 g heavier than those caught with the 7.62-cm mesh. For L. guttatus, the optimum length (100% retention probability) was 29.1 cm for the 7.62-cm mesh and 33.9 cm for the 8.89-cm mesh; for L. argentiventris, the optimum length for the 7.62-cm mesh was 28.9 cm and for the 8.89-cm mesh, 33.7 cm. In both cases the catch mode corresponds to the calculated optimum length. The gillnet of 7.62-cm mesh caught the largest abundance in terms of number of individuals and biomass; however, the 8.89-cm mesh assures the catch of organisms that have reached first maturity length.
PLOS ONE, 2017
There is great concern regarding the population status of the endangered Galapagos sea lion (GSL)... more There is great concern regarding the population status of the endangered Galapagos sea lion (GSL) because it has drastically decreased over the last 30 years. We determined the population size and growth trend of the GSL in the Galapagos southeastern region (SER) at three population levels based on the available census data: 1) SER (2011-2015), including 13 rookeries on the four islands San Cristó bal (SC), Española, Floreana, and Santa Fe, comprising 58% of the archipelago's population; 2) SC (2011-2015), including five rookeries, comprising 52% of the SER population; and 3) El Malecó n (2005-2015), the largest rookery on SC and in the SER (43% of the population on SC and 22% in the SER). We also analyzed the influence of environmental variability on pup abundance in these rookeries. The current GSL population size in the SER, after applying correction factors to the counts, is estimated at approximately 2300-4100 individuals and has declined at an average annual rate (ʎ) of 8.7% over the last five years. A similar trend was determined for SC but at ʎ = 1.4% during the same period. For El Malecón, a count-based population viability analysis using a diffusion approximation approach showed that the population increased from 2005 to 2015 at ʎ = 2%. The interannual variability in pup abundance was associated with anomalies in sea surface temperature linked to oceanographic-atmospheric events, which impact the abundance and availability of prey, and ultimately may determine the population's reproductive success. Since rookeries in the SER had different population trends, management actions should be implemented based on their specific conditions, giving priority to rookeries such as El Malecón, which, despite showing a slightly increasing population trend, still faces a high risk of extinction due to anthropogenic disturbances and environmental variability that may affect its growth and survival.
Fishing power, efficiency and selection of gallnets for the shorfisin grunt (Microlepidotus brevipinnisSteincachner, 1869) in the southern coast of Jalisco, Mexico
Cambio climático y el colapso de la pesquería de camarón rosado (Farfantepenaeus duorarum) de la Sonda de Campeche
Se presentan las evidencias de la asociación del colapso de la pesquería de camarón del la sonda ... more Se presentan las evidencias de la asociación del colapso de la pesquería de camarón del la sonda de Campeche, y en particular del camarón rosado (Farfantepenaeus duorarum), con eventos de cambio climático de las últimas cuatro décadas. Los rendimientos anuales del camarón rosado son actualmente 5% de los que se obtenían en la década de los 60 (cercanos a las 18 000 t), con el consecuente efecto negativo sobre la economía y desarrollo social de la región. Se describe la interpretación inicial de eventos como la sobrepesca, impactos negativos de corto plazo de diferente origen, y la degradación de la zona costera como causantes del estado del recurso; así como las evidencias que destacan el efecto del cambio climático como agente conductor de la tendencia decreciente de la abundancia del recurso desde inicio de la década de los 70. Se pre- sentan como evidencia las tendencias de las anomalías del reclutamiento durante el periodo de 1970 a la mitad de la década de los 90, con respecto a las anomalías de la producción primaria del ecosistema, la temperatura, salinidad, nivel medio del mar y el índice de oscilación del Atlántico norte. Se concluye señalando la estrategia de manejo adoptada para esta condición del recurso.
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Papers by Francisco Arreguin-Sanchez