Edad y crecimiento de Paralonchurus peruanus “suco” procedente de la pesca artesanal de la Región La Libertad de febrero a diciembre del 2014

El objetivo de esta investigación fue determinar la edad y crecimiento de Paralonchurus peruanus “coco”, mediante la interpretación de anillos de crecimiento en 491 pares de otolito sagitta, procedente de la pesca artesanal de la Región La Libertad de febrero a diciembre 2014. Del análisis de microincrementos se comprobó que la periodicidad de formación de los anillos de crecimiento fue anual. Se elaboró una clave talla-edad, al no encontrar diferencias significativas entre sexos. Asimismo, se obtuvo 8 edades (3, 4, 5, 6, 7, 8, 9, 10), de los cuales predomino el de 3 años. Se obtuvo la distribución por edades. La relación entre la longitud total del pez y el radio total del otolito fue lineal y la relación longitud total entre peso total fue potencial con un b= 2.9, presentando un crecimiento alométrico. Se estimó los parámetros de crecimiento de von Bertalanffy mediante el programa Table Curve 2D V5. 01, siendo estos L∞ = 54.71 cm; K = 0.145 años; t0 = -0.618 años. Las ecuaciones de las curvas de crecimiento en longitud y peso fueron Lt = 54.71*(1-e(-0.145*(t-0.618))) y Wt=1826.7* (1-e(-0.145*(t-0.618)) respectivamente.

Evaluación de bancos naturales de invertebrados marinos comerciales, Región La Libertad-Perú, 2012

En la Región la Libertad, la mayor producción pesquera artesanal descansa en tres pesquerías del ámbito costero: cangrejo violáceo, caracol negro y pulpo. La pesca de altura de la pota, es importante por los volúmenes que aporta a la pesquería. La evaluación, se realizó en el litoral de la Región La Libertad, desde Chérrepe (7°9’35,4”S – 79°41’8,2”W) hasta isla Corcovado (8°56’25,8”S - 78°41’49,4”W), del 8 al 28 de octubre 2012. El trabajo se efectuó en dos etapas: 16 días por mar y 5 días por mar somero, y comprendió los diversos tipos de muestreos en las estaciones, tanto biológicas como oceanográficas. El estudio se efectuó en treinta y nueve bancos de invertebrados marinos: siete de caracol negro, cuatro de pulpo, dos de concha de abanico, dos de almeja, dos de muy muy, cuatro de pepino de mar, y dieciocho de cangrejo violáceo.

End-to-end modelling for an ecosystem approach to fisheries in the Northern Humboldt Current Ecosystem

This work represents an original contribution to the methodology for ecosystem models' development as well as the rst attempt of an end-to-end (E2E) model of the Northern Humboldt Current Ecosystem (NHCE). The main purpose of the developed model is to build a tool for ecosystem-based management and decision making, reason why the credibility of the model is essential, and this can be assessed through confrontation to data. Additionally, the NHCE exhibits a high climatic and oceanographic variability at several scales, the major source of interannual variability being the interruption of the upwelling seasonality by the El Niño Southern Oscillation, which has direct e ects on larval survival and sh recruitment success. Fishing activity can also be highly variable, depending on the abundance and accessibility of the main shery resources. This context brings the two main methodological questions addressed in this thesis, through the development of an end-to-end model coupling the high trophic level model OSMOSE to the hydrodynamics and biogeochemical model ROMS-PISCES: i) how to calibrate ecosystem models using time series data and ii) how to incorporate the impact of the interannual variability of the environment and shing. First, this thesis highlights some issues related to the confrontation of complex ecosystem models to data and proposes a methodology for a sequential multi-phases calibration of ecosystem models. We propose two criteria to classify the parameters of a model: the model dependency and the time variability of the parameters. Then, these criteria along with the availability of approximate initial estimates are used as decision rules to determine which parameters need to be estimated, and their precedence order in the sequential calibration process. Additionally, a new Evolutionary Algorithm designed for the calibration of stochastic models (e.g Individual Based Model) and optimized for maximum likelihood estimation has been developed and applied to the calibration of the OSMOSE model to time series data. The environmental variability is explicit in the model: the ROMS-PISCES model forces the OSMOSE model and drives potential bottom-up e ects up the foodweb through plankton and sh trophic interactions, as well as through changes in the spatial distribution of sh. The latter e ect was taken into account using presence/ absence species distribution models which are traditionally assessed through a confusion matrix and the statistical metrics associated to it. However, when considering the prediction of the habitat against time, the variability in the spatial distribution of the habitat can be summarized and validated using the emerging patterns from the shape of the spatial distributions. We modeled the potential habitat of the main species of the Humboldt Current Ecosystem using several sources of information ( sheries, scienti c surveys and satellite monitoring of vessels) jointly with environmental data from remote sensing and in situ observations, from 1992 to 2008. The potential habitat was predicted over the study period with monthly resolution, and the model was validated using quantitative and qualitative information of the system using a pattern oriented approach. The nal ROMS-PISCES-OSMOSE E2E ecosystem model for the NHCE was calibrated using our evolutionary algorithm and a likelihood approach to t monthly time series data of landings, abundance indices and catch at length distributions from 1992 to 2008. To conclude, some potential applications of the model for shery management are presented and their limitations and perspectives discussed.