Mauricio Ramírez-Rodríguez

Life history stage duration and natural mortality for the pink shrimp Farfantepenaeus duorarum (Burkenroad, 1939) in the southern Gulf of Mexico, using the gnomonic model for time division

The gnomonic model proposed by Caddy [Aquat. Living Resour. 9 (1996) 197] to estimate life history stage duration and natural mortality values (M) is applied to the pink shrimp Farfantepenaeus duorarum of the southern Gulf of Mexico. Estimates of life history stage duration and M were consistent with other estimates in the literature. Evidence from the literature suggests that M declines with age, which is also reflected by results through the gnomonic model. If the product of natural mortality and duration for gnomonic intervals is close to constant, as assumed by the model, then age specific natural mortality rates estimated in this study may be useful in modeling and managing the fishery for pink shrimp.

Growth and fisheries of the Black Ark Anadara tuberculosa, a bivalve mollusk, in Bahia Magdalena, Baja California Sur, Mexico

Abstract To determine trends in landings and growth of the pustulose ark or black ark Anadara tuberculosa, a bivalve mollusk in the Bahia Magdalena–Bahia Almejas region along the southwestern coast of the Baja California Peninsula, Mexico, catch statistics recorded by artisan or small-scale fishermen from 1992 to 2002 and size frequency distributions of samples from commercial catches (November 1998–December 2000) were analyzed. Catch data revealed considerable fluctuations and a trend toward decline. No defined seasonal exploitation pattern was observed; however, on average, the months with the highest catches coincided with the highest reproductive activity. There was evidence of a decrease in black ark density, which might be accounted for by the fishery. Parameters derived from the von Bertalanffy growth equation confirm that individuals reach the minimum catch size of 60 mm in a little more than 1 year. Catch sizes ranged between 40 and 80 mm.

GROWTH OF PINK SHRIMP FARFANTEPENAEUS DUORARUM (BURKENROAD, 1939) IN CAMPECHE SOUND, MEXICO

[The growth of Farfantepenaeus duorarum in Campeche Sound was analysed from length-frequency data collected from February 1984 through December 1988. The monthly anomalies of the catch structure for commercial categories, and the monthly relative importance of small, medium, and large shrimp show that the main cohort is recruited to the fishing grounds during October. Following the evolution of this cohort with the ELEFAN I method, we found that the Von Bertalanffy growth equation parameters with seasonal fluctuations were larger than those reported for the same species in the Tortugas fishing grounds, southern Florida. The growth performance index,  ′, does not show substantial variation during the four biological years analysed, probably as a result of the relatively stable environment in Campeche Sound. Con datos de frecuencias de tallas recolectados de febrero de 1984 a diciembre de 1988, se estudio el crecimiento de Farfantepenaeus duorarum en la Sonda de Campeche, Mexico. El analisis se basa en el seguimiento de la evolucion de la cohorte principal que, de acuerdo a la informacion sobre biologia de la especie, las anomalias mensuales en la estructura de la captura comercial, y la importancia relativa por mes de camarones chicos, medianos y grandes, se recluta a la zona de pesca en octubre. Los parametros de la ecuacion de crecimiento de Von Bertalanffy, con oscilaciones estacionales, se estimaron con el metodo ELEFAN I. Los valores fueron mayores que los reportados para la misma especie en el norte del Golfo de Mexico. El indice del patron crecimiento,  ′, no presento variaciones importantes en los cuatro anos biologicos, probablemente como resultado del ambiente estable de la Sonda de Campeche., The growth of Farfantepenaeus duorarum in Campeche Sound was analysed from length-frequency data collected from February 1984 through December 1988. The monthly anomalies of the catch structure for commercial categories, and the monthly relative importance of small, medium, and large shrimp show that the main cohort is recruited to the fishing grounds during October. Following the evolution of this cohort with the ELEFAN I method, we found that the Von Bertalanffy growth equation parameters with seasonal fluctuations were larger than those reported for the same species in the Tortugas fishing grounds, southern Florida. The growth performance index,  ′, does not show substantial variation during the four biological years analysed, probably as a result of the relatively stable environment in Campeche Sound. Con datos de frecuencias de tallas recolectados de febrero de 1984 a diciembre de 1988, se estudio el crecimiento de Farfantepenaeus duorarum en la Sonda de Campeche, Mexico. El analisis se basa en el seguimiento de la evolucion de la cohorte principal que, de acuerdo a la informacion sobre biologia de la especie, las anomalias mensuales en la estructura de la captura comercial, y la importancia relativa por mes de camarones chicos, medianos y grandes, se recluta a la zona de pesca en octubre. Los parametros de la ecuacion de crecimiento de Von Bertalanffy, con oscilaciones estacionales, se estimaron con el metodo ELEFAN I. Los valores fueron mayores que los reportados para la misma especie en el norte del Golfo de Mexico. El indice del patron crecimiento,  ′, no presento variaciones importantes en los cuatro anos biologicos, probablemente como resultado del ambiente estable de la Sonda de Campeche.]

Fishing Time and Trap Ghost Fishing for Cancer johngarthi along the Baja California Peninsula's Southwestern Coast, Mexico

Abstract During trap-fishing investigations on the crab Cancer johngarthi along Baja California peninsulas southwestern coast, Baja California Sur, Mexico, conducted between 2002 and 2006, information was gathered to assess fishing efficiency in terms of the number of crabs caught per trap during one hour of operation (catch per unit of effort, CPUE = c/ht). As a result of vessel operation issues, some trap lines were abandoned, whereas vessels returned to land for repairing, and because the effective fishing time for these traps was significantly longer than normal, the information so obtained was regarded as reflecting the potential effect on fishing of traps lost during fishing operations (ghost fishing). Of 651 line sets analyzed, involving 45,152 traps, 77% had effective fishing times below 60 h, 14% between 70 and 150 h and 9% between 150 and 5,500 h. There is an exponential reduction in CPUE with increasing fishing time that could be associated to trap saturation. The number of crabs per trap also...During trap-fishing investigations on the crab Cancer johngarthi along Baja California peninsulas southwestern coast, Baja California Sur, Mexico, conducted between 2002 and 2006, information was gathered to assess fishing efficiency in terms of the number of crabs caught per trap during one hour of operation (catch per unit of effort, CPUE = c/ht). As a result of vessel operation issues, some trap lines were abandoned, whereas vessels returned to land for repairing, and because the effective fishing time for these traps was significantly longer than normal, the information so obtained was regarded as reflecting the potential effect on fishing of traps lost during fishing operations (ghost fishing). Of 651 line sets analyzed, involving 45,152 traps, 77% had effective fishing times below 60 h, 14% between 70 and 150 h and 9% between 150 and 5,500 h. There is an exponential reduction in CPUE with increasing fishing time that could be associated to trap saturation. The number of crabs per trap also decreased with immersion time, fitting a power function. After 1,000 h of immersion, each trap may contain 7–18 crabs. Four hundred traps were lost over the course of 14 fishing trips. However, because the fishery is in the early development phases, the implementation of measures to avoid or restrain ghost fishing is deemed convenient.

Stock size estimation of the mexican crab, Cancer Johngarthi Carvacho, 1989 on the southwestern peninsula of Baja California, Mexico

[Stock size of the Mexican crab, Cancer johngarthi was evaluated off the southwestern coast of the peninsula of Baja California (23°19′ to 26°04′N 110°16′ to 113°32′W) from three trap surveys executed from November 2002 to February 2003 on a commercial vessel. Surveys were made in depths of 80 to 300 m, using lines with an average of 87 traps per line, and a total of 183 hauls. Available stock size was estimated through a stock-reduction model considering both closed and open population assumptions. For all surveys, 15 experimental areas were selected. A total of 393,272 crabs were caught during the operations. The unit of effort was defined as hour-trap (h-t), and latitudinal gradient of catch rates (crabs per h-t) were observed. The average available stock-size ranged between 0.127 and 14.3 million crabs and catchability from 0.0000089 to 0.0013 crabs/h-t. The average harvest rates over the 15 experimental areas were about 1%. Even when results suggest a possible development of a new fishery, we suggest to realize more research specifically aimed at seasonal variation, reproductive aspects, and to execute an analysis of variation of catchability and stock size in order to predict conditions to initiate a commercial exploitation of the Mexican crab, Cancer johngarthi off the southwestern coast of the peninsula of Baja California. Se evaluo el tamano poblacional del cangrejo mexicano Cancer johngatrthi en la costa sur occidental de la peninsula de Baja California (de 23°19′ a 26°04′ Latitud Norte y de 110°16′ a 113°32′ Longitud Oeste) a partir de tres cruceros de una embarcacion comercial de noviembre de 2002 a febrero de 2003. La investigacion se realizo en profundidades de 80 a 300 m, usando lineas con un promedio de 87 trampas por linea y un total de 183 lances. El tamano del stock disponible fue estimado por un modelo de reduccion de stock considerando los supuestos de poblacion cerrada y abierta. Se definieron 15 zonas experimentales para todos los cruceros y se logro una captura total de 393,272 cangrejos. Se definio la unidad de esfuerzo como hora-trampa (h-t) y se observo un gradiente latitudinal en la tasa de captura (cangrejos por h-t). El tamano del stock disponible promedio vario entre 0.127 a 14.3 millones de cangrejos y la capturabilidad de 0.0000089 a 0.0013 cangrejos/h-t. La tasa de cosecha promedio para todas las areas experimentales fue del 1%. Los resultados obtenidos sugieren la posibilidad de desarrollar una nueva pesqueria, sin embargo, se sugiere profundizar en las investigaciones, especificamente en las variaciones estacionales, en los aspectos reproductivos y en las variaciones de capturabilidad y del tamano del stock para prevenir las condiciones necesarias para iniciar una explotacion comercial del cangrejo mexicano Cancer johngarthi en la costa sur occidental de la peninsula de Baja California. , Stock size of the Mexican crab, Cancer johngarthi was evaluated off the southwestern coast of the peninsula of Baja California (23°19′ to 26°04′N 110°16′ to 113°32′W) from three trap surveys executed from November 2002 to February 2003 on a commercial vessel. Surveys were made in depths of 80 to 300 m, using lines with an average of 87 traps per line, and a total of 183 hauls. Available stock size was estimated through a stock-reduction model considering both closed and open population assumptions. For all surveys, 15 experimental areas were selected. A total of 393,272 crabs were caught during the operations. The unit of effort was defined as hour-trap (h-t), and latitudinal gradient of catch rates (crabs per h-t) were observed. The average available stock-size ranged between 0.127 and 14.3 million crabs and catchability from 0.0000089 to 0.0013 crabs/h-t. The average harvest rates over the 15 experimental areas were about 1%. Even when results suggest a possible development of a new fishery, we suggest to realize more research specifically aimed at seasonal variation, reproductive aspects, and to execute an analysis of variation of catchability and stock size in order to predict conditions to initiate a commercial exploitation of the Mexican crab, Cancer johngarthi off the southwestern coast of the peninsula of Baja California. Se evaluo el tamano poblacional del cangrejo mexicano Cancer johngatrthi en la costa sur occidental de la peninsula de Baja California (de 23°19′ a 26°04′ Latitud Norte y de 110°16′ a 113°32′ Longitud Oeste) a partir de tres cruceros de una embarcacion comercial de noviembre de 2002 a febrero de 2003. La investigacion se realizo en profundidades de 80 a 300 m, usando lineas con un promedio de 87 trampas por linea y un total de 183 lances. El tamano del stock disponible fue estimado por un modelo de reduccion de stock considerando los supuestos de poblacion cerrada y abierta. Se definieron 15 zonas experimentales para todos los cruceros y se logro una captura total de 393,272 cangrejos. Se definio la unidad de esfuerzo como hora-trampa (h-t) y se observo un gradiente latitudinal en la tasa de captura (cangrejos por h-t). El tamano del stock disponible promedio vario entre 0.127 a 14.3 millones de cangrejos y la capturabilidad de 0.0000089 a 0.0013 cangrejos/h-t. La tasa de cosecha promedio para todas las areas experimentales fue del 1%. Los resultados obtenidos sugieren la posibilidad de desarrollar una nueva pesqueria, sin embargo, se sugiere profundizar en las investigaciones, especificamente en las variaciones estacionales, en los aspectos reproductivos y en las variaciones de capturabilidad y del tamano del stock para prevenir las condiciones necesarias para iniciar una explotacion comercial del cangrejo mexicano Cancer johngarthi en la costa sur occidental de la peninsula de Baja California. ]

Selectivity of traps for the deep-water crab, Cancer johngarthi Carvacho, 1989 in the northern Mexican Pacific

Nine crab-trap lines were set off the west coast of Baja California Sur, Mexico, from June 2000 to May 2001. Traps were of different types: conic, rectangular, and rhombic. We analysed the efficiency of the traps for Cancer johngarthi, a crab species that represents between 80 and 99% of total crab catch at locations ranging from 100 to 530 m deep. Other fauna (14 species) was scarce. The catch of C. johngarthi consisted of males with a carapace width (CW) >125 mm and, depending on the trap type, relative abundance values from 0.05 to 1.2 crabs per trap-hour. According to the catch-per-unit-effort for gender and size, the most efficient type of traps were the conic ones, whereas rhombic traps were the least efficient. The sizes at first catch for females were 109, 101, and 86 mm CW for conic, rectangular, and rhombic types, respectively. For males the values were 136, 134, and 78 mm CW. Though the existence of C. johngarthi was known, this is the first report of experimental fishing targeting this species. Preliminary results suggest that management strategies will be heavily dependent on taking into account the observed variability in catch effectiveness of the various traps. The use of different traps will facilitate the managers decision regarding sizes and catch rates. En este trabajo se analiza la eficiencia de las trampas para la captura de Cancer johngarthi. De junio de 2000 a mayo de 2001 se realizaron nueve lances de pesca de prospeccion pesquera con lineas de trampas para cangrejo, de tipo conico, rectangular y rombico, operadas entre 100 m y 530 m de profundidad, frente al litoral occidental de Baja California Sur, Mexico. C. johngarthi se presento en 5 de los 9 lances y constituyo del 80 al 99% de la captura total. La fauna de acompanamiento fue escasa y estuvo compuesta por 14 especies. En la captura de C. johngarthi predominaron individuos machos de tamano superior a los 125 mm de ancho de cuerpo (AC), con valores desde 0.05 a 1.2 cangrejos por hora-trampa, dependiendo del tipo de trampa. Al considerar la CPUE por sexo y talla, las trampas conicas fueron las mas eficientes, capturando mas machos que hembras, siendo los individuos de tamano superior a los 120 mm de AC. Las trampas rombicas fueron las menos eficientes. La talla de primera captura para hembras fue de 109, 101 y 86 mm de AC en las trampas conicas, rectangulares y rombicas, respectivamente. Para machos, los valores fueron de 136 mm de AC, 134 mm de AC y 87 mm de AC. Los resultados sugieren que las estrategias de manejo de la naciente pesqueria de C. johngarthi deberan considerar la variabilidad observada y el tipo de trampa para decidir sobre tallas y tasas de captura.

Juvenile pink shrimp, Farfantepenaeus duorarum (Burkenroad, 1939): length composition in three nursery areas in campeche sound, Gulf of Mexico

Characteristics of the recruitment of juvenile pink shrimp, Farfantepenaeus duorarum in three nursery areas in Campeche Sound, southern Gulf of Mexico, were analysed from length-frequency data collected from 1992 through 1995, and from catch-per-unit-effort data from 1994 to 1995. Three juvenile size categories were determined: small (10-39 mm TL), medium (40-49 mm TL), and large (50-130 mm TL). The abundance was higher during the rainy and windy months, and was lower during the dry season, but there were differences in duration of the recruitment season and in the size of the shrimp recruiting to each area. Small juvenile pink shrimp were present all year, which gives evidence of continuous reproduction with different intensities. The 1995 recruitment season was shorter than that in 1994 and showed low abundance. The monthly size composition of juvenile pink shrimp was related to gear selectivity, but true values probably depend on environmental influences on recruitment. The size composition of juvenile F. duorarum can change by zone or season. Para determinar caracteristicas del reclutamiento de juveniles de camaron rosado Farfantepenaeus duorarum a tres areas de crianza en la costa de la Sonda de Campeche, Mexico, se analizan datos de frecuencia de tallas recolectados de 1992 a 1995 y de captura por unidad de esfuerzo de 1994 y 1995. Se determino la importancia relativa de las categorias de camarones juveniles chicos (10-39 mm LT), medianos (40-49 mm LT) y grandes (50-130 mm LT). El patron de abundancia muestra valores altos durante la estacion de lluvias y vientos, y bajos en la seca. Se observaron cambios en la duracion de las temporadas de reclutamiento y en los tamanos de los camarones que se reclutan. Los individuos chicos estuvieron presentes todo el ano, evidenciando la reproduccion continua. La temporada de 1995 fue mas corta que la de 1994 y la abundancia de juveniles disminuyo notablemente. En la composicion por tallas influye la selectividad de los artes de pesca y puede suponerse su relacion con efectos ambientales. Se encontraron cambios por area y temporada en la composicion de tallas de los juveniles.

Biochemical Changes During the Reproductive Cycle of Haliotis fulgens (Philippi, 1845) (Gastropoda: Archaeogastropoda) on the Baja California Sur West Coast

ABSTRACT This article describes the changes in the concentration of lipids, proteins, and carbohydrates in the gonad, digestive gland, foot and mantle of Haliotis fulgens over a reproductive cycle. An average of 30 specimens was collected each month between September 2011 and August 2013 from La Bocana, Baja California Sur, Mexico. The biometrics of each specimen were recorded, and gonads were processed using a standard histological method. Additionally, from February 2012 to February 2013, portions of nonfixed organs were frozen at -54°C for use in proximal analyses. This species showed gonadal development and spawning throughout the study period, with a peak in spawning from September through February, coinciding with sea surface temperatures near 20°C and the beginning of the decline in daylight. This study demonstrates that this species utilizes proteins, lipids, and carbohydrates stored in the foot during gonadal development and that lipid levels decrease in both the digestive gland and the gonad during spawning.

A Profitability Analysis of Catch Quotas for the Pacific Hake Fishery in the Gulf of California

AbstractFishing for Pacific Hake Merluccius productus in the Gulf of California is carried out by shrimp trawlers. When the shrimp fishing season ends, these boats shift to catching Pacific Hake and other finfish. The Pacific Hake fishery is relatively new and has the potential to grow as an industry. Therefore, there is interest in defining management plans to create a sustainable fishery. One option is an individual vessel quota system. This paper estimates the per-vessel quota in the Pacific Hake fishery that achieves a break-even operation and estimates the number of vessels that could enter the fishery to avoid overexploitation and overcapacity. Potential per-vessel quotas were estimated based on the cash flow of a representative trawler and the estimate of total Pacific Hake biomass. The results indicate that individual catch quotas for Pacific Hake should be 90.4 or 100 metric tons to achieve a 30% or 45% increase, respectively, in net cash. Additionally, with total allowable catch values equivalen...

Managing Artisanal Fisheries in Estuarine Systems Through the Use of Fishing Zones in the South Eastern Gulf of California

Artisanal fisheries in the estuarine systems of Mexico are poorly regulated due to fishery complexity and the lack of information on the biology of exploited species, their habitat and fishing methods. Due to these unknowns and to utilize existing catch data (i.e., landing date, catch and landing site, catch per species, and price), this chapter proposes the use of zones as management units to understand fishing processes by region, and to identify possible spatiotemporal changes of the marine communities along the coast of Sinaloa (SE Gulf of California). A total of 97 species, primarily teleost fishes (n = 80), composed the artisanal catch within 6 defined zones; the shrimp fishery was also important in all the zones. The importance of other fisheries differed according to zone, but in general, swimming crabs were most economically important in the North and demersal fishes were most important in the South. Three categories of target species were classified: high economic value and high abundance seasonal species; low abundance and high value resident species; and high abundance and low value resident species. Zonation will allow the identification of catch trends, which can be used for management; however, there still remains essential information that is needed for better management.