Estimation of the Maximum Sustainable Yield and the Optimal Fishing Effort of the Blue Crab (<em>Callinectes sapidus</em>, Rathbun 1896) of Laguna Madre, Tamaulipas, Mexico

The fishery of the blue crab (Callinectes sapidus) in Laguna Madre (LM), Tamaulipas, Mexico, with an average annual catch of 3307 tons, is of great importance economically and socially. The objective of this research was to estimate the carrying capacity (K), the catchability coefficient (q), the maximum sustainable yield (MSY) (tons), and the optimal fishing effort (fMSY) (traps). For this, a time series from 1998 to 2012 was used for the catch and number. The Fox (1970) and Schaefer (1954) models included in A Surplus-Production Model Incorporating Covariates (ASPIC) software were employed for this study. A set of statistical variability estimators and the Akaike?s, Bayesian, and Hannan-Quinn information criteria were used for the selection of models. The results obtained by the fox model were K = 54,000, q = 0.00008798, MSY = 2567 and fMSY = 146,900 traps, whereas for the Schaefer model, the results were K = 28,370, q = 0.00002425, MSY = 2008, and fMSY = 58,390. The model with the best adjustment was that of Schaefer. It is concluded that the fishing resource has been overexploited during the period 2003–2011, with an average annual surplus of 670 tons and 25,000 traps. It is recommended to consider the MSY and fMSY values of the Schaefer model for the National Fishing Charter (NFC)

Modeling the Individual Growth of the Bonnethead Shark Sphyrna tiburo of the Western Gulf of Mexico Using the Multimodel Approach

To describe the growth pattern of the bonnethead shark (Sphyrna tiburo) in the Gulf of Mexico, a von Bertalanffy (VB) model has been automatically fit, which indicated a single&minus;phase continuous growth without oscillations, though this would generate biases if this hypothesis is not confirmed. The objective of this research was to describe the growth pattern of S. tiburo under a multimodel approach based on information theory and contrasting single&minus;phase models (VB, Gompertz, logistic models, and variants) and biphasic models (Soriano model and variants). The VB model was not supported. The Soriano model, with the variant in growth rate (k) and including length at birth (L0), was selected with 100% supporting evidence. The hypothesis of the two&minus;phase growth of S. tiburo with an increase in k, more than L&infin;, fitted to L0, is confirmed, and a correspondence was identified between growth&minus;phase change sizes and the sizes reported in the literature for change in the juvenile&ndash;adult stages in females and for onset of reproductive maturity in males and both sexes

Estimación del rendimiento máximo sostenible del recurso tiburón-cazón en México

In Mexico, shark catch ranks 10th place out of the 22 most representative fisheries in the country, with an estimated annual average number of 29 772 T and an economic income of approximately MXN 437 million. The maximum sustainable yield (MSY), which means the maximum catch that can be obtained without the depletion of the fishing resource at any given time is one of the main points of reference in the evaluation of fisheries. In this study, the MSY of sharks in Mexico was estimated for 26 coastal areas (Mexico, Pacific ocean, gulf of Mexico, 6 regions of the NOM-029-PESC-2006 and 17 coastal States). Catch time series (CTS) were used in tons per year of reported catch (Rc) and total catch (Tc) (reported catch + non-reported catch) over the 1976 to 2014 period. In addition, empirical models that relate the maximum catch of the STM to the MSY were applied. There were no significant differences between the models applied. Based on the estimated Tc and MSY (T x 103) there is an over-exploitation of sharks in Mexico (Tc = 51 417, MSY = 29 040), in the Pacific ocean (Tc = 38 654, MSY = 20 840) and in the gulf of Mexico (Tc = 15 737, MSY = 14 540); in Regions 2 (gulf of California) (Tc = 22 664, MSY = 14 330) and 5 (coastal line of Tamaulipas, Veracruz and Tabasco) (Tc = 9 202, MSY = 8 510) and on thecoast of the States of Baja California (Tc = 5 781, MSY = 4 880) and Baja California Sur (Tc = 5 950, MSY = 5 510). It is recommended to urgently address the problem of using this fishery resource in the Mexican Republic.En México, la captura del recurso pesquero tiburón-cazón (RTC) ocupa el décimo lugar delas 22 pesquerías más representativas del país, con un volumen anual promedio estimado en 29 772 T, y una derrama económica de 437 millones de pesos mexicanos. La captura máxima que se puede obtener sin agotar el recurso en ningún plazo, se denomina rendimiento máximo sostenible (RMS), y es uno de los principales puntos de referencia en la evaluación de pesquerías. El objetivo del presente estudio fue estimar el rendimiento máximo sostenible del recurso pesquero tiburón-cazón, agrupándolo en 26 regiones (México, océano Pacífico, golfo de México, 6 regiones de la NOM-029-PESC-2006 y 17 estados costeros). Se utilizaron series de tiempo de captura (STC), en toneladas por año de captura reportada (Cr) y captura total (Ct) (captura reportada + captura no reportada) del periodo de 1976 a 2014, y se aplicaron modelos empíricos que relacionan la captura máxima de la STC con el RMS. No hubo diferencias significativas entre los modelos. Con base en la Ct y el RMS estimados (T x 103) se evidencia una sobreexplotación del RTC en México (Ct = 51 417, RMS = 29 040), en el océano Pacífico (Ct = 38 654, RMS = 20 840) y en el golfo de México (Ct = 15 737, RMS = 14 540); en la Región 2 (golfo de California) (Ct = 22 664, RMS = 14 330) y Región 5 (línea costera de Tamaulipas, Veracruz y Tabasco) (Ct = 9 202, RMS = 8 510), y en la costa de los estados de Baja California (Ct = 5 781, RMS = 4 880) y Baja California Sur (Ct = 5 950, RMS = 5 510). Es necesario atender de forma urgente la problemática del aprovechamiento de este recurso pesquero en la república mexicana

Inferencia multimodelo aplicada a la relación longitud total-peso eviscerado en tiburones: El caso del tiburón martillo cabeza de pala Sphyrna tiburo: Multi-model inference applied to the total length-gutted weight relationship in sharks: The case of the bonnethead shark Sphyrna tiburo

En la modelación de la relación longitud-peso (RLP) en tiburones siempre se ha ajustado el modelo potencial [modelo lineal (L) en versión logarítmica], nunca se ha aplicado la inferencia multimodelo (IMM) y siempre se ha asumido un crecimiento constante en todas las fases del desarrollo ontogénico. El tiburón martillo cabeza de pala (Sphyrna tiburo) del Golfo de México, no es la excepción. Mediante la modelación de la RLP en hembras (H), machos (M) y sexos combinados (C) de S. tiburo, y aplicando la IMM [modelos (L), cuadrático, cúbico, broken-stick (BS), dos segmentos (DS), BS y DS con transición logística entre segmentos] basada en la teoría de la información (TI), se probó la hipótesis de que el ajuste de L es insuficiente para describir la RLP en tiburones. Ningún modelo fue seleccionado con un peso de evidencia a su favor (wi%) mayor al 90%. La IMM evidenció un ajuste insuficiente en L (wi% = 0,86, 72,70 y 0,45%, en H, M y C, respectivamente), y significativo en el modelo promedio (wi%= 99,14, 27,30 y 99,55%, en H, M y C respectivamente); y demostró que el crecimiento cambia en función de la talla y presenta un marcado cambio morfológico en cierta talla específica, manifestado por los tres tipos de crecimiento registrados en H y C [alométrico negativo (CAN) y positivo (CAP), y crecimiento isométrico (CI)], y los dos en M (CI y CAP), cuyos cambios entre tipos de crecimiento fueron coincidentes con el cambio de dieta juvenil-adulto y el inicio de la madurez sexual, reportados por la literatura