Juan Carlos Gutiérrez Estrada

University of Huelva | UHU · Departamento de Ciencias Agroforestales

Jellyfish blooms along coastal areas can pose significant challenges for beach users and local authorities. Understanding the factors influencing jellyfish presence is crucial for effective management and mitigation strategies. In this study, citizen science data from the Andalusian coast (232 beaches, in 40 different localities) and machine learni...

This article introduces a control architecture designed for the development of Hybrid Remotely Operated Underwater Vehicles. The term ”Hybrid” characterizes Remotely Operated systems capable of autonomously executing specific operations. The presented architecture maintains teleoperation capabilities while enabling two fully autonomous applications...

The implementation of a system to assess the risk of Amyloodinium ocellatum occurrence in rearing ponds in fish farms located in southern Spain is a fundamental aspect to ensure the economic viability of these facilities. For this purpose, a computer program (called Amy) for Windows PCs and an application for mobile devices (AmyAPP), based on the A...

Jellyfish swarms have a direct negative impact on human enterprise, specially on places dependent on the sun and beach economy. The local economy and the health of bathers may be at risk from the emergence of these gelatinous organisms. Economic losses can be mitigated by monitoring the occurrence of jellyfish on the coast. Due to the lack of jelly...

Knowing the activity of fishing vessels accurately and in real time means a leap in quality in the management of fishing activity. This paper presents the development of a new fishing activity monitoring integral system (FAMIS) that can complement and overcome the limitations of current fishing vessel monitoring systems (VMS). FAMIS is developed on...

Based on, catch reconstructed data, we constructed the fisheries of the Pagellus genus between 1950 and 2014 in FAO Major Fishing Areas 27 and 34 and overall by continent and by species, namely, Pagellus acarne, Pagellus bellottii, Pagellus bogaraveo and Pagellus erythrinus. Additionally, we considered the group Pagellus sp. to include species iden...

To know the abundance of fishes and their size distribution in the semi-intensive rearing systems in tradidional ponds is an aspect key to plan and manage efficiently the sales lots. Usually this information is obtained by means of sampling which mandatory supposes a direct catch and stressful and time consuming management of fishes. Therefore, in...

Este artículo describe una propuesta para modificar la arquitectura de control de un Vehículo Operado Remotamente (ROV) destinado a la toma de datos e inspección de granjas acuícolas. La propuesta se basa en incluir un nuevo módulo de Localización, encargado de posicionar distintos tipos de elementos que se encuentren alrededor del ROV y puedan ser...

The Blackspot Seabream (Pagellus bogaraveo) is one of the most important commercially exploited fish species for the Spanish and Moroccan fleets which operate in the Strait of Gibraltar. In recent years, the landings of Blackspot Seabream in the main ports have decreased significantly with respect to previous periods of maximum catches, which makes...

Tourism, fishing and aquaculture are key economic sectors of Costa del Sol (southern Iberian Peninsula). The management of these activities is sometimes disturbed by the onshore arrival and stranding of jellyfish swarms. In the absence data on the occurrence of these organisms, it may be interesting to explore data from non-driven systems, such as...

Adequately assess the environmental effects on commercially exploited fish stocks is one of the main challenges faced by stock managers in their attempt to achieve ecosystemic management. In this study, we have developed a methodology which allows simulate the evolution of abundance or biomass of a fish population and calculate two indexes (the sig...

The Blackspot seabream (Pagellus bogaraveo) is one of the most important fishery resources in the region of the Strait of Gibraltar. The fishery of this demersal species, carried out by the Spanish and Moroccan artisanal fleets, is highly vulnerable to overexploitation whose effects can be enhanced by environmental and regulatory changes. This stud...

Drought temporal characterization is a fundamental instrument in water resource management and planning of basins with dry-summer Mediterranean climate and with a significant seasonal and interannual variability of precipitation regime. This is the case for the Lower Guadiana Basin, where the river is the border between Spain and Portugal (Algarve-...

Fisheries management is generally based on the regulation of the fishing effort, by limiting fishing capacity and activity. The fishing capacity can be quantified objectively, however, the calculation of the fishing activity requires knowing the effective fishing time, for which it is essential to monitor the vessels activity. The European Vessel M...

In this study we carried out an analysis of the relationship between the variation in environmental and oceanographic parameters and the changes in the abundance of blackspot sea bream (Pagellus bogaraveo) in the Strait of Gibraltar between 1983 and 2016. A discrete dynamic model was applied to simulate different scenarios of blackspot sea bream bi...

We assessed the potential for simulation and modelling of the blackspot seabream (Pagellus bogaraveo) population in the Strait of Gibraltar to discriminate the environmental effects of fishery impacts. A discrete biomass-abundance dynamic model was implemented to obtain a simulated monthly time series of blackspot seabream biomass. On this simulate...

Actualmente existe un acuerdo entre la mayoría de la comunidad científica, alrededor de la idea de que los sistemas de producción y consumo energético del ser humano están alterando rápidamente la variabilidad climática del planeta, ocasionando serios impactos sobre los sistemas naturales y socioeconómicos. Ante este contexto de rápido cambio climá...

En el proyecto SimFish se está desarrollando actualmente un software de propósito general (SimFish v1.0) que permite simular de forma precisa a una escala de tiempo mensual el ciclo de vida y evolución temporal de la abundancia y biomasa prístina de una población de peces. A partir de esta serie de abundancia o biomasa simulada es fácil de evaluar...

Las redes neuronales artificiales constituyen una buena alternativa a los modelos convencionales para estimar diferentes variables en ingeniería del riego, entre ellas la evapotranspiración de referencia, clave en la determinación de las necesidades de agua de riego. En este artículo se presenta una metodología didáctica para introducir al alumno e...

Como propuesta de trabajo práctico dirigido se ha planteado el diseño, desarrollo e implementación de un sistema experto que permite la simulación de modelos de lógica borrosa o difusa. Este sistema experto se ha utilizado en la resolución de un problema de ingeniería real, la regulación automática de los caudales de entrada de agua en balsas de pl...

The use of different trawl nets is a factor to be considered when analysing historical swept-area research surveys aimed to characterize temporal variations in the relative abundance of demersal resources. If factors that may affect the performance of the bottom trawls were considered, more reliable temporal trends could be established. Due to the...

This study analysed the possibility of using the sea surface temperature (SST) of the Atlantic Ocean to predict the recruitment of European eels in one of the most important estuaries of the south of Europe. For this purpose, two different time series concerning glass eel in the Guadalquivir estuary (the first obtained from a set of fishery-indepen...

Grid gates with multiple sharp-crested rectangular orifices are used to control manually water discharge from branch channels to semi-intensive aquaculture ponds. Experimental and analytical analysis related to the discharge characteristics of these grid gates under submerged flow conditions have been presented in this paper with the objective to i...

In this paper, we assess the performance of fuzzy inference systems (FISs) and the consistency of fuzzy rules generated from a meta-analysis exploring diversity–environment relationships, in a system of temporary and fluctuating ponds located in two regions of southern England. The analyses focus on aquatic coleopteran assemblages, which act as exc...

This study illustrate the use of indicators and models to support the Ecosystem Approach to Fisheries and Aquaculture management using two case studies in Chile: prediction of environmental variability effects upon anchovy (Engraulis ringens) fishery of northern Chile and prediction of suitable sites and carrying capacity of Pacific oyster (Crassos...

This study illustrate the use of indicators and models to support the Ecosystem Approach to Fisheries and Aquaculture management using two case studies in Chile: prediction of environmental variability effects upon anchovy (Engraulis ringens) fishery of northern Chile and prediction of suitable sites and carrying capacity of Pacific oyster (Crassos...

A model comprising blocks of artificial neural networks (ANNs) combined in sequence was used to simulate the inflow and outflow in a water resources system under a shortage of water. We assessed the selection of appropriate input data using linear and non-linear cross-correlation functions and sensitivity analysis. The potential model inputs were f...

In this research a physical hydraulic model was build in a laboratory under controlled conditions for the experimental calibration of grid gates with multiple sharp-crested rectangular orifices. These gates provide accurate measurements for a wide range of flows without discontinuities. Based on the laboratory's dimensions, a geometric scale of 1:9...

Several linear and non-linear models for centralized remote-control systems that can support decision making of semi-intensive aquaculturists concerning the inflow rates to the ponds were evaluated. These models were: multiple linear regressions (MLRs), generalized additive models (GAMs), artificial neural networks (ANNs) and fuzzy logic controller...

Queirolo, D., Hurtado, C. F., Gaete, E., Soriguer, M. C., Erzini, K., and Gutiérrez-Estrada, J. C. 2012. Effects of environmental conditions and fishing operations on the performance of a bottom trawl. – ICES Journal of Marine Science, 69: 293–302. Trawl performance was studied based on net spread and variability in the contact of the footrope with...

Six morphometric traits (height at withers, height at rump, chest depth, width at hips, width at pins and rump length) were analysed to characterise from a breed point of view 518 females from four autochthonous Andalusian cattle breeds (Berrenda en Colorado, Berrenda en Negro, Cárdena Andaluza and Negra Andaluza). Four methods (one classical and t...

The energy cost is one of the most important cost components in the water supply systems. Since large amounts of electricity are required to pump, transport and apply water, the profitability of some business, as irrigation districts or fishfarms, which use the water as production resource, is heavily dependent upon energy costs. Methodologies that...

Abstract The performance of robust principal component analysis (RPCA), detrended correspondence analysis (DCA) and non-metric multidimensional scaling (NMDS) with two demersal fish data sets were assessed in terms of their stability to bootstrap-generated sample variation and the method’s ability to reflect a well-known depth gradient. Stability w...

The energy cost is one of the most important cost components in the water supply systems. Since large amounts of electricity are required to pump, transport and apply water, the profitability of some business, as irrigation districts or fishfarms, which use the water as production resource, is heavily dependent upon energy costs. Methodologies that...

El objetivo principal de la tesis desarrollada es conseguir una mejora del régimen de explotación en una piscifactoría de anguilas europeas (Anguilla anguilla L.) a través de unas herramientas de predicción y simulación lo suficientemente fiables, que permitan al acuicultor prever a corto y medio plazo los acontecimientos que van a suceder desde un...

Although both seasonal patterns and short-term variation in CPUE are known to occur in most fisheries, particularly small-scale coastal fisheries, the analysis of their underlying factors have received little attention to date. When these factors become part of the local fishermen's ecological knowledge, the resulting peak abundances are often inte...

An evaluation of the performance of artificial neural networks (ANNs) to forecast monthly anchovy (Engraulis ringens) and sardine (Sardinops sagax) catches in northern Chile (18°21′S-24°S) is presented, using environmental variables, anchovy and sardine CPUE, fishing effort and catches between 1963 and 2007. An analysis of previous data was carried...

An understanding of the causal mechanisms and processes that shape macroinvertebrate communities at a local scale has important implications for the management and conservation of freshwater biodiversity. Here we compare the performance of linear and non-linear statistics to explore diversity–environment relationships using data from 76 temporary a...

Hydroacoustic techniques are a valuable tool for the stock assessments of many fish species. Nonetheless, such techniques are limited by problems of species identification. Several methods and techniques have been used in addressing the problem of acoustic identification species. In this paper, schools of anchovy, common sardine, and jack mackerel...

Size selectivity of the deep water longline used in the black spot seabream (Pagellus bogaraveo) fishery in the Strait of Gibraltar was studied with data of four sizes of hooks. Logistic (classic) and Artificial Neural Networks (heuristic) selectivity models were fitted for two experimental fishing trials. Logistic selectivity model was adequate fo...

In this study the performances of computational neural networks (CNNs), multiple linear regressions (MLRs) and generalised additive models (GAMs) to predict Pacific sardine (Sardinops sagax) landings and to analyse their relationships with environmental factors in the north area off Chile were studied. For this purpose several local and global envi...

The European Water Framework Directive (WFD; 2000/60/EC) establishes a framework for the protection of all waters. Transitional waters are functional units with fluctuating and unstable dynamics, which leads to a high abundance and species diversity. The reference condition for a water body is the description of the biological quality elements that...

Species and size selectivity of the deep water longline traditionally used in commercial fishing of the black spot seabream (Pagellus bogaraveo) were studied in the Strait of Gibraltar with four sizes of hooks. Black spot seabream contributed up to 88% of the catch by number. Catch and by-catch rates differed for the different hooks and fishing tri...

Recently, Computational Neural Networks (CNNs) and fuzzy inference systems have been successfully applied to time series forecasting. In this study the performance of a hybrid methodology combining feed forward CNN, fuzzy logic and genetic algorithm to forecast one-day ahead daily water demands at irrigation districts considering that only flows in...

The energy cost is one of the most important cost components in the water supply systems. Since large amounts of electricity are required to pump, transport and apply water, the profitability of some business, as irrigation districts or fishfarms, which use the water as production resource, is heavily dependent upon energy costs. Methodologies that...

Background. The deep-water longline fishery of the blackspot seabream, Pagellus bogaraveo, is an economically important fishery in the Strait of Gibraltar, which is a very complex transition ecosystem between the Mediterranean Sea and the Atlantic Ocean with an extreme spatial and temporal variability. This paper presents a series of morphometric r...

The problem of selecting the best combination of pipe diameters of water distribution networks of fishfarms is analysed in this paper. With this goal, an optimisation algorithm with a rule of thumb to limit the range of flow velocities was developed. The available range of flow velocities was selected according to hydraulics constraints and fouling...

Relationships between environmental variables and diversity (Shannon-Weaver index) of the fish communities in the Tagus estuary and adjacent coastal areas were analyzed. The focus was on the linearity or nonlinearity of these abiotic/biotic characteristics, with the aim to obtain an accurate short–medium term time-scale diversity prediction from ha...

A first approach to the pelagic fisheries non-linear modelling was presented by Gutiérrez-Estrada et al. (2007) using a univariate ANN model considering anchovy catches of the previous six months. In this study the performance of artificial neural networks monthly forecast models for anchovy catches in northern Chile (18°21’S-24°S) considering twel...

In the present paper, two univariate forecasting techniques were tested to evaluate the short-term CPUE capacity forecast for Pacific halibut, Hippoglossus stenolepis (Pleuronectidae). The first methodology, based on the Box–Jenkins approach (autoregressive integrated moving average models [ARIMA models]), assumes a linear relationship between the...

In this study the performance of computational neural networks (CNNs) models to forecast 1-month ahead monthly anchovy catches in the north area of Chile considering only anchovy catches in previous months as inputs to the models was analysed. For that purpose several CNN approaches were implemented and compared: (a) typical autoregressive univaria...

On the Atlantic coasts of Andalucía, chronic spring–summer (March–June) diarrhetic shellfish poisoning (DSP) outbreaks are associated with blooms of Dinophysis acuminata, Claparède and Lachmann. Artificial neural networks (ANNs) have been successfully used to model primary production and have recently been tested for the prediction of harmful algae...

This work analyses the effect that the electrical market liberalisation has on the variation of water temperature regimes in intensive aquaculture plants, and more specifically, the fishfarms which take advantage of the cooling effluents from power plants. Data were obtained from a facility devoted to the European eels growth which takes the warm w...

An algorithm for selection of least cost or optimum pump combinations in water supply systems and to evaluate the system's energy cost of inland intensive fishfarms is presented. The model is based on solving a non-linear programming problem. Optimum design refers to the selection of pump type, capacity, and number of units that results in minimum...

The use of near-infrared reflectance spectroscopy (NIRS) calibrations to predict the ingredient composition in compound feeds (i.e., inclusion percentage of each ingredient) is a complex task, regarding both the nature of the parameters to be predicted, since they are not well-defined chemical entities, and the heterogeneousness of the matrices/for...

The design, development and testing of a prototype interactive expert system (SEDPA) capable of diagnosing eel pathologies is described. The system incorporates a multiple subprogram modular design, although only the inference engine is largely described. Its user interface incorporates a natural language module. Starting from this kind of informat...

El control y la predicción de parámetros físico-químicos del agua en tanques de cultivo de plantas de producción en medio acuático es un aspecto fundamental del buen funcionamiento de este tipo de instalaciones. En este trabajo se propone la estimación de la temperatura del agua en las próximas 24 horas en una planta de producción de anguilas europ...

One of the main problems in the management of fishfarms with water recirculating system is the forecasting and control of ammonia concentration in order to minimise the fish stress status. This paper examines methodologies of prediction in a real-time environment for an eel intensive rearing system. Approaches based on linear multiple regression, u...

One of the main problems in the management of large water supply and distribution systems is the forecasting of daily demand in order to schedule pumping effort and minimize costs. This paper examines methodologies for consumer demand modeling and prediction in a real-time environment for an on-demand irrigation water distribution system. Approache...

Time should be considered in carrying out the design and management of demand irrigation distribution systems. In this paper, a method to characterize the pumping flow in demand pressurized systems throughout the day and irrigation season is presented. This method considers the temporal evolution of water requirements during the irrigation season a...

La demanda de agua es la magnitud de referencia en la gestión óptima de los sistemas de distribución. En este trabajo se propone la estimación de la demanda en las próximas 24 horas en un sistema de distribución de agua para riego, y se utilizan, junto con los métodos tradicionales de predicción de regresión múltiple y de modelos univariantes de se...

In this paper, we propose an alternative method to predict the Gonadosomatic Index (GSI), based on a technique known as computational neural networks (CNNs), with two main objectives: (1) to develop a quick and reliable method for the prediction of the fish reproductive period under variable environmental conditions, and thus (2) to reduce the fiel...

The age structure, growth and reproduction of Lepomis gibbosa (L. 1758) (= L. gibbosus) was studied from March 1993 to September 1994 in a tributary stream of the Guadalquivir River. The maximum age observed was 5+ years both in males and females. In the O+ group, seasonal growth began in February and lasted 8 months. Males and females matured duri...

The distribution and apparent habitat preference of the common mummichog (Fundulus heteroclitus) in south-western Spain were examined during summer–autumn 1996. This introduced species was more or less continuously distributed along the Atlantic coast of Spain, being more abundant in sites near the coastline (usually 25. It was the most frequently...

La presencia de un depósito de regulación en un sistema de impulsión permite independizar los caudales bombeados de la variabilidad del uso del agua en la red de distribución. De este modo el depósito se podrá utilizar, además de como acumulación del recurso agua, en la reducción de los costes energéticos al poder adaptar el esquema de operación de...