Notes on taxonomy, biology and fishery of Ucides occidentalis (Brachyura: Ocypodidae) with emphasis in the Gulf of Guayaquil, Ecuador

La información científica sobre Ucides occidentalis es escasa y parte de estos estudios no han logrado una difusión adecuada, lo cual restringe la disponibilidad de conocimiento sobre esta especie comercial. En este trabajo se revisan diversos estudios sobre U. occidentalis y se presenta información obtenida de observaciones directas realizadas entre 2011-2014 en los manglares del Golfo de Guayaquil, Ecuador. Se muestran notas sobre cambios en la taxonomía de U. occidentalis, sus características biológicas, ecológicas y pesqueras. Se discuten características del interés pesquero como la densidad poblacional y períodos de reproducción. Finalmente, se discute el manejo de las pesquerías de U. occidentalis en el Golfo de Guayaquil debido a que, en los últimos años, se ha evidenciado una disminución en los niveles de desembarques y a la vez, un aumento en la talla media comercial; aquello sugiere que se deben considerar ambos factores en la evaluación del stock, para tener una mejor aproximación sobre el estado poblacional del recurso y sus niveles de explotación.Scientific information on Ucides occidentalis is scarce, and part of these studies have not adequate diffusion, this situation restricts the availability of knowledge about this commercial species. In this work, on the one hand, diverse studies on U. occidentalis are reviewed, and on the other, information obtained from direct observations made since 2011 to 2014 in the Gulf of Guayaquil mangroves, is presented. Notes on changes in the taxonomy of U. occidentalis, its biology, ecological and fishery characteristics are presented. Characteristics to fishing interest such as density data and reproduction periods are discussed. By last, it is discussed the management of fisheries of U. occidentalis in the Gulf of Guayaquil, because in recent decades, U. occidentalis has evidenced a decrease in the landing levels and at the same time, an increase in the average commercial size; this suggest that both factors should be considered in the evaluation of stock, and thereby to have a better approximation on the population status of the resource

Importancia de la variabilidad climática en las pesquerías y biología de la merluza europea Merluccius merluccius (Linnaeus, 1758) de la costa noroccidental africana

Tesis doctoral[Summary] Fish population and fisheries fluctuations are closely linked to climate dynamics through environmental variability that determines the distribution, migration and abundance of fish. Fishery science were largely focused on the great northern hemisphere fisheries, which some of them fluctuate at decadal time scales and show patterns of synchrony with low frequency signals, as reflected by climatic indices such as the North Atlantic Oscillation (NAO). However, there is scarce information about these patterns at lower latitudes like NW African coast, in spite of this area supports large international fisheries. The aim of this work was to analyze how climate variability described by NAO and the physical environment influences the productivity of European hake abundance, growth and recruitment variability. The European hake is widely distributed in the North Atlantic and their southern distribution limit is located in NW Africa. Historically it has been carried out an important multinational fishery in this area. In order to understand why it is important to test the climatic hypothesis over European hake stock, I presented the background elements in three main discussion lines. In Chapter 1, I compared the biology and population dynamics between European hake of NW Africa and populations from North Atlantic and Mediterranean Sea. In Chapter 2, it is described and analyzed the structure and evolution of European hake fisheries in NW Africa, focused on unexplained variability of stock assessment procedures carried out until now. In Chapter 3, the main climatic and environmental features of NW African coast are described, emphasizing the potential deterministic influence that variability of these features might exert on the biology, population dynamics and fisheries of European hake in this area. In Chapter 4, catch-based abundance indices of Moroccan and Spanish fisheries were used as the dependent variables in correlation analysis with NAO index. Time series analysis techniques were applied to ICOADS data and satellite data of wind stress and phytoplankton biomass as upwelling proxies to assess their dependence with NAO index. It was found a positive relationship between the NAO and hake abundance. NAO explained 35-45% variability of juveniles with 1-year lag and 45- 60% of small and large adults with 2-3-years lag. The NAO index is a proper tool to trace the annual growth of European hake, at least during the first three years of life. Based on this, it is suggested that the growth rate is greater than previous calculus in the area, and it supports the fast growing hypothesis proposed for North Atlantic and Western Mediterranean. The wind stress explained 83% of phytoplankton biomass variability and both of them were positively correlated with NAO index (41- 58% explained variability respectively). The hake abundance was positively related with favorable oceanographic and productive regime associated with positive NAO conditions. The increasing of upwelling events appear to promote increased abundance of hakes mainly during early life stages, probably throughout enhanced productivity conditions. In Chapter 5, it was tasted the relative importance of climate variability on recruitment dynamics estimated from fishery data and scientific Moroccan surveys. The recruitment to the fishery took place during all year with peaks in spring and summer, but the seasonal component was weak. The time series were in synchrony with NAO index of the previous year and showed strong positive correlation. The recruitment success variability explained by NAO was 25 to 82 % depending on time series size. The main NAO effect in recruitment dynamics was the widening-contraction of Recruitment Window. During NAO+ phase several success cohorts were recruited by year, while in NAO- the success cohorts were scarce and weak. The climate signal in recruitment dynamics of European hake was robust, recurrent and persistent independently of fishing effort. Finally, in Chapter 6, the NAO index was included as a state variable in a Ricker Stock-recruitment-environment model, to contrast it with classical Ricker and Beverton & Holt models. The NAO factor enhanced the fitting model and determined the dispersion degree of recruitment at certain stock level, just before of overcompensation effect of Ricker curve. This exercise represents a step forward in order to include the environmental variability induced by climatic system in stock assessment of demersal resources of NW Africa.[Resumen] El impacto de los cambios de escala climática sobre la producción pesquera mundial es una cuestión relevante científica y económicamente, ya que algunas de las principales pesquerías marinas muestran variaciones temporales en sincronía con oscilaciones climáticas. Por esta razón, en años reciente se ha puesto mayor atención en investigar de qué forma responden los ecosistemas marinos a la variabilidad climática natural, y cómo este conocimiento puede ser incorporado en la gestión de los recursos pesqueros. Sin embargo, dilucidar el impacto del clima sobre las pesquerías no es una tarea sencilla, porque se trata de un proceso holístico de gran escala que interactúa con multiplicidad de factores locales que determinan en última instancia el impacto sobre las poblaciones explotadas. Por lo tanto, el objetivo principal de este trabajo de tesis fue analizar de forma amplia la importancia relativa de la variabilidad del clima descrita por la Oscilación del Atlántico Norte (NAO) en la evolución de las pesquerías y la dinámica de población de la merluza europea en la costa Noroccidental Africana. Para entender la necesidad de explorar la hipótesis climática como fuente de variación principal, primero se proporcionan elementos de discusión acerca de los conceptos de referencia que sustentan tal posibilidad, en tres líneas principales. En el CAPÍTULO 1, se analiza comparativamente la biología y dinámica poblacional entre la merluza europea de la costa Noroccidental Africana y las poblaciones de la especie que se distribuyen en el Atlántico norte y Mediterráneo. En el CAPÍTULO 2, se describe y analiza la estructura y evolución de las pesquerías dirigidas a esta especie en el área de estudio, haciendo énfasis en la variabilidad no explicada por las evaluaciones del stock llevadas a caobo hasta el momento. En el CAPÍTULO 3, se presenta una descripción del entorno climático y ambiental de la costa Noroccidental Africana, y se discute acerca del potencial de influencia que la variabilidad de este entorno pudiera tener en la biología, dinámica poblacional y las pesquerías de la merluza europea en esta área geográfica en particular. Posteriormente, en el CAPÍTULO 4 se estableció que la abundancia de merluza europea está correlacionada significativa y positivamente con el índice NAO. La variabilidad de la abundancia de juveniles es explicada por la NAO en un 35-45% con un año de desfase y entre 45 y 60% la de adultos tempranos y adultos grandes, con 2 y 3 años de desfase respectivamente. El desfase del impacto, permite utilizar el índice NAO como trazador del crecimiento anual de la merluza europea, cuya magnitud fue el doble de la estimada en trabajos anteriores en el área. El proceso que presumiblemente vincula la variabilidad climática descrita por la NAO y la abundancia por grupos de talla de la merluza europea, es la extensión espacial y temporal de los afloramientos inducidos por viento. El estrés de viento explica el 83% de la variabilidad de la biomasa de fitoplancton y ambos parámetros se correlacionaron positivamente con el índice NAO del mismo año. Es decir, que la abundancia de juveniles está directamente relacionada con un régimen oceanográfico y productivo favorable asociado con fases positivas de la NAO. Como consecuencia de lo anterior, en el CAPÍTULO 5 se exploró la contribución relativa de la señal climática a la dinámica del reclutamiento de la especie a través de índices derivados de las pesquerías y de campañas científicas. Se determinó que el reclutamiento a la pesquería sucede a lo largo de todo el año, con máximos en primavera y verano, pero con estacionalidad débil. El reclutamiento varía en fase con la NAO del año previo (25-82% de la variabilidad explicada). El mecanismo de respuesta ecológico a las variaciones de la NAO, fue la ampliación-contracción de la Ventana de Reclutamiento (VR). Durante una fase positiva de la NAO, se reclutan varias cohortes en un mismo año, en tanto que durante una fase negativa, el número e intensidad de cohortes reclutadas disminuye sensiblemente. La señal climática en el reclutamiento es robusta, recurrente y persistente independientemente del nivel de esfuerzo de pesca. Finalmente, en el CAPÍTULO 6 se incorporó el índice NAO como un parámetro ambiental en un modelo stock-reclutamiento, que mejora el ajuste de los datos con respecto a los modelos clásicos. El factor NAO determina la dispersión del reclutamiento a un mismo nivel del stock reproductor, previo a la sobre-compensación de la curva de reclutamiento. Esto representa un paso muy importante hacia la incorporación de la variabilidad ambiental inducida por el sistema climático en la evaluación de los stocks demersales de la costa Noroccidental Africana.Instituo Español de Oceanografía; Consejo Nacional de Ciencia y Tecnología (Conacyt) del Gobierno Mexicano; Fundación Meiners-Mandujan

Climate variability and recruitment success of European hake (Merluccius merluccius L.) in NW Africa

Recently it was stated a strong dependence of European hake abundance with climate variability in NW Africa. This relationship was explained by the North Atlantic Oscillation (NAO) driving the upwelling temporality and its geographic coverage, which could be responsible of changes in survival rate during early life stages of this species. Following this hypothesis, this work focuses on the relative importance of climate variability on recruitment dynamics of European hake. Interannual variability of recruitment success were analyzed through two types of time series: (i) from monthly and annual length distribution fishery data (1982-1999) of Spanish trawling fleet that worked under Spanish or European-Moroccan fishery agreements and (ii) recruits annual abundance from scientific Moroccan surveys (1982-2004). The time series were compared with the annual smoothed NAO index to evaluate the type of relationship, persistence and their relative contribution as a variation source of recruitment success. The recruitment to the fishery took place during all year with peaks in spring and summer, but the seasonal component was weak. The time series were in synchrony with NAO index of the previous year and showed strong positive correlation. The variation of recruitment success explained by NAO was 25 to 82 % depending on time series size. The main NAO effect in recruitment dynamics was the widening-contraction of Recruitment Window. During NAO+ phase several success cohorts were recruited by year, while in NAO- the success cohorts were scarce and weak. The climate signal in recruitment dynamics of European hake was robust, recurrent and persistent independently of fishing effort

Time-space reproductive differences of black hakes, M. polli and M. senegalensis off the NW African Coast

PosterThe named black hake in the Northwest Africa, M. polli and M. senegalensis, are distributed in Saharan, Mauritanian and Senegalese waters, where they are target species of Spanish trawling fleet and by some longliners. The separation of both species is quite difficult in practice, hence they are usually considered as black hake (mixed) in commercial catch statistics. This fact and the considerable deep distribution range of M. polli, results in a marked scarcity of comparative detailed studies about these species. The aim of this work was to analyze detailed biological data, collected during research trawl surveys and scientific observations onboard of commercial trawlers and longilenrs in Mauritanian and Senegalese waters during 2003-2006. By macroscopic analysis of the gonadic stages and the seasonal evolution of gonadosomatic indices (GSI), it has been determined the spawning season of both species. In order to determine the size at first sexual maturity, a logistic model was fitted to the mature fraction by length separated by species, considering different time periods. In other hand, the monthly time series of commercial gonad yields between 1986 and 2006 were split up in the trend and the seasonal components using a X-12 ARIMA routine. The spawning took place during the cold season, from November to February with the strongest signal during December-January for both species, but it occurs quite early in M. senegalensis. Males consistently maturing earlier than females, but there was a little length difference of sexual maturity for the two species. M. senegalensis reached the first maturity (35,4 cm) at slightly lower length than M. polli (37,0 cm) for combined sexes model. The sex ratio was skewed to females in both species. Because these species inhabits into a highly dynamic oceanographic area, and taking in account that recently it has been suggested a strong dependence between the climate-environment proxy NAO and the black hakes adult abundance dynamics, we explored possible deterministic relationships between reproduction features and sexual maturity of both species in phase with NAO index. It was not possible to determine if the difference in length-maturity values with some previous analyses were related with changes in abundance, the environmental forcing, or due to calculus procedures. However there was synchrony between the pronounced negative NAO phase and decreasing amplitude of seasonal peak of gonad yields for both species. Finally, despite of there was a slightly asynchrony in spawning timing among both species, we believe that in general terms it is justified to consider one set of maturity parameter values to perform the assessment procedures.Instituto Español de Oceanografía (IEO

Índice de desenvolvimento municipal da micro e pequena empresa - ID-MPE do Rio Grande do Sul

The promotion of public policy development, focusing on results, needs indicators for monitoring its effectiveness. The indices of municipal development, synthetic indices that capture certain aspects of local development, serve as reference for the diagnosis and monitoring of the results of the action of public management, such as important tools for planning. The ID-MPE - Municipal Development Index of Micro and Small Enterprise has as propose to guide the strategies and local policies of economic promotion, aiming to capture the favorable conditions for the establishment and growth of small local businesses. Applying the methodology of the ID-MPE for Rio Grande do Sul State shows the municipalities with the best business environments for the flourishing of MPE's, and serves as a benchmark for the promotion of local development policies based on the General Law of Micro and Small Enterprise.Local development; micro and small firms; local development index

Reproductive biology of little tunny Euthynnus alletteratus (Rafinesque, 1810) in the southwest Gulf of Mexico

The aim of this study was to describe the reproductive dynamic of Euthynnus alletteratus in the southwest Gulf of Mexico. The annual variation of the volume fraction occupied by gametes and tissues in gonads were related with main body indexes, such as the gonadosomatic index (IG), the hepatosomatic index (IH), and the nutrition index (IN), and compared with the sea surface temperature. A total of 951 E. alletteratus individuals were sampled, where a sex ratio of 1:1 and a size interval strongly skewed towards organisms with a fork length (LF) of 36–40 cm were observed. The IG showed an increase from March to September with maximum values in April and July. Two clearly defined peaks were observed, and they were consistent with the histological analysis, where the percentage of ripe gametes predominated from April to September. The optimum thermal window for reproductive activity was from 24 to 28 °C. The size of first sex maturity was 34.35 cm of LF for males and 34.60 (LF) for females, without significant difference between sexes

Dinámica poblacional del pez invasor del género Pterygoplichthys en la cuenca de Chacalapa (cuenca de Coatzacoalcos) Veracruz, México

La presencia reciente del Pterygoplichthys, comúnmente conocidos como plecos, pez diablo o limpia peceras, en las aguas epicontinentales de la zona de Chinameca, Veracruz, se ha convertido en un problema ecológico y ambiental, debido a que por su enorme plasticidad adaptativa y a la ausencia de depredadores naturales, provoca desplazamiento de especies nativas. Actualmente en el estado de Veracruz no se cuenta con trabajos de investigación que permitan sustentar medidas de control y/o erradicación del Pterygoplichthys. Con el objetivo de obtener datos básicos del Pterygoplichthys, se llevaron a cabo muestreos biológicos bimestrales, sobre la parte baja del río Chacalapa y la represa artesanal adyacente denominada “La Chinampita”. Los muestreos iniciaron en el mes de julio de 2012 y culminaron en mayo de 2013, se realizaron con artes de pesca poco selectivos. Se determinó la presencia de la especie P. pardalis, con individuos de 420 mm de longitud total (LT) y un peso de 620 g en los machos, en las hembras fue de 390 mm LT y 650 g. Los registros de captura que mayor abundancia de plecos presentaron, fueron en el mes de mayo con el 43%. A partir del mes de marzo se registró el inicio de la actividad reproductiva, con máximo desarrollo gonadal en mayo

An integrative taxonomic approach reveals Octopus insularis as the dominant species in the Veracruz Reef System (southwestern Gulf of Mexico)

The common octopus of the Veracruz Reef System (VRS, southwestern Gulf of Mexico) has historically been considered as Octopus vulgaris, and yet, to date, no study including both morphological and genetic data has tested that assumption. To assess this matter, 52 octopuses were sampled in different reefs within the VRS to determine the taxonomic identity of this commercially valuable species using an integrative taxonomic approach through both morphological and genetic analyses. Morphological and genetic data confirmed that the common octopus of the VRS is not O. vulgaris and determined that it is, in fact, the recently described O. insularis. Morphological measurements, counts, indices, and other characteristics such as specific colour patterns, closely matched what had been reported for O. insularis in Brazil. In addition, sequences from cytochrome oxidase I (COI) and 16S ribosomal RNA (r16S) mitochondrial genes confirmed that the common octopus from the VRS is in the same highly supported clade as O. insularis from Brazil. Genetic distances of both mitochondrial genes as well as of cytochrome oxidase subunit III (COIII) and novel nuclear rhodopsin sequences for the species, also confirmed this finding (0–0.8%). We discuss our findings in the light of the recent reports of octopus species misidentifications involving the members of the ‘O. vulgaris species complex’ and underscore the need for more morphological studies regarding this group to properly address the management of these commercially valuable and similar taxa

Duración e intensidad de la puesta y su dependencia del tamaño corporal: El caso del bonito Euthynnus alletteratus capturado en el suroeste del Golfo de México

In terms of fish dynamic population, reproduction is a process related with corporal size of each population member, which is tied with the spawning time and number of eggs produced. In order to relate the size of female little tuny (Euthynnus alletteratus), located in the southwest Gulf of Mexico, and its contribution in reproductive process, cycle and reproductive characteristics were analyzed by different size groups. Biological data were obtained by the artisanal fishing fleet of Antón Lizardo Veracruz community (Mexico). A total of 480 fish were caught from December 2009 to November 2012. Size structure, gonadosomatic index and duration and intensity spawning index (IDI) were determined. The gonadosomatic index showed a decrease in the population after April and July. Nevertheless, these months and the fraction of spawning female may vary depending on size groups. According with the IDI, the individuals with the highest contribution in reproductive process belong to sizes from 44 to 56 cm. Therefore, in order to guarantee the conservation of this species, it is imperative to mainly direct the management measures towards the females from these sizes

Duración e intensidad de la puesta y su dependencia del tamaño corporal: El caso del bonito Euthynnus alletteratus capturado en el suroeste del Golfo de México

In terms of fish dynamic population, reproduction is a process related with corporal size of each population member, which is tied with the spawning time and number of eggs produced. In order to relate the size of female little tuny (Euthynnus alletteratus), located in the southwest Gulf of Mexico, and its contribution in reproductive process, cycle and reproductive characteristics were analyzed by different size groups. Biological data were obtained by the artisanal fishing fleet of Antón Lizardo Veracruz community (Mexico). A total of 480 fish were caught from December 2009 to November 2012. Size structure, gonadosomatic index and duration and intensity spawning index (IDI) were determined. The gonadosomatic index showed a decrease in the population after April and July. Nevertheless, these months and the fraction of spawning female may vary depending on size groups. According with the IDI, the individuals with the highest contribution in reproductive process belong to sizes from 44 to 56 cm. Therefore, in order to guarantee the conservation of this species, it is imperative to mainly direct the management measures towards the females from these sizes