Influence of Production Strategy on Gross Waste Output and Temporal Pattern of Gilthead Seabream (Sparus Aurata) Farming: Implications for Environmental Management

This study compares the farm management model used in the Mediterranean gilthead seabream (GHSB; Sparus aurata) industry (S1)—stepped entry of juveniles throughout the year with several production cycles and fish ages overlapping in a single farm—with that used in the salmon industry (S2)—the whole is farm filled with fish that are the same age at once with a fallowing period between rearing cycles—in terms of waste production by coupling digestibility coefficients with growth, feeding, and eating behavior models into a mass balance model. We considered the total C, N, and P content in the different waste fractions (particulate and dissolved wastes). The model, which simulated real farming conditions, showed relevant quantitative and qualitative differences between both strategies, with stocked biomass and water temperature as the main drivers, the amount of feed wasted by chewing as the most relevant fraction differentiating both strategies, and the fallowing period as the main distinguishing management feature. We discuss the influence of both farming strategies on some key performance and environmental aspects, such as benthic recovery, the breakdown of the life cycle of pathogens, and adaptability to climate change. Our results suggest that changing the GHSB industry’s production model is necessary for its sustainability.Versión del edito

Consumption of particulate wastes derived from cage fish farming by aggregated wild fish. An experimental approach

Particulate wastes derived from cage fish farming are a trophic resource used by wild fish. This study assesses waste consumption by wild fish and the impact on the final balance of wastes. Consumption was determined according to the difference between the particulate matter exiting the cages and that reaching 5 m away at three different depths, in the presence and absence of wild fish. Wild fish around the experimental cages were counted during feeding and non-feeding periods. A weighted abundance of 1057 fish 1000 m−3 consumed 17.75% of the particulate wastes exiting the cages, on average. Consumption was higher below the cages, where waste outflow was greater. However, waste removal by wild fish was noteworthy along the shallow and deep sides of the cages. Wild fish diminished the net particulate wastes by about 14%, transforming them into more easily dispersible and less harmful wastes. This study demonstrates the mitigating potential of wild fish in reducing environmental impact.This research was funded by the Spanish Institute of Agro-Forestry Research (INIA; Ministry of Economy and Competitiveness; project RTA2011-00088-00-00). The study was also partially sponsored by the student grant sub-programme for researcher training, of the Spanish Institute of Agro-Forestry Research (FPI-INIA)

Competencia por el alimento entre el cormorán moñudo, el cormorán grande y la pesca artesanal: un caso de estudio

The Mediterranean shag (Phalacrocorax aristotelis desmarestii) and the great cormorant (P. carbo sinensis) are syntopic birds in an area encompassing Grosa Island and the Mar Menor coastal lagoon (SE Spain, western Mediterranean) during the breeding season of the former and the wintering period of the latter. Diet composition of both birds was studied through pellet analysis and otolith identification. Competition for fish resources between these two seabirds and with local artisanal fisheries was assessed. Shags preyed preferentially on small pelagic fish, and great cormorants mainly consumed demersal fish. Shag diet consisted of marine fish strictly, but great cormorant fed in all the available environments in the study area, including marine, transitional (coastal lagoon) and freshwater reservoirs. The great dissimilarity observed between shag and great cormorant diet composition showed no competition between them. The low shag population density and fishing effort in their foraging area suggested no competition with fisheries. Conversely, great cormorant population density in the study area was very high, and they foraged on fish of high commercial value. However, competition between great cormorant and artisanal fisheries only affected some of the less abundant species fished.El cormorán moñudo (Phalacrocorax aristotelis desmarestii) y el cormorán grande (P. carbo sinensis) son especies sintópicas en el entorno de Isla Grosa y la laguna costera del Mar Menor (SE de España, Mediterráneo occidental) durante la época de reproducción del primero que coincide con la invernada del segundo. Se estudia la composición de la dieta de ambas especies mediante la identificación de otolitos en sus egagrópilas, y se evalúa la competencia entre ambas especies y con la pesca artesanal local. El cormorán moñudo se alimentó mayoritariamente de pequeños peces pelágicos, y el cormorán grande consumió principalmente peces demersales. La dieta del cormorán moñudo consistió estrictamente de peces marinos, mientras que el cormorán grande capturó peces en los diferentes ambientes acuáticos de la zona de estudio, incluyendo especies marinas, de lagunas costeras e incluso de embalses de agua dulce. La gran disimilitud observada entre la composición de la dieta de ambas aves nos indica que no existe competencia por el alimento entre ellas. Asimismo, la baja densidad poblacional de cormorán moñudo y su esfuerzo pesquero en la zona de estudio tampoco demuestran competencia con la pesca artesanal local. Por el contrario, la abundancia de cormorán grande en la zona de estudio es muy alta, y se alimentaron principalmente de especies de alto valor comercial para los pescadores locales. No obstante, solo se observó competencia con la pesca artesanal local por alguna especie de pez de las menos abundantemente capturadas por los pescadores

Monitoring coastal lagoon water quality through remote sensing: The Mar Menor as a Case study

The Mar Menor is a hypersaline coastal lagoon located in the southeast of Spain. This fragile ecosystem is suffering several human pressures, such as nutrient and sediment inputs from agriculture and other activities and decreases in salinity. Therefore, the development of an operational system to monitor its evolution is crucial to know the cause-effect relationships and preserve the natural system. The evolution and variability of the turbidity and chlorophyll-a levels in the Mar Menor water body were studied here through the joint use of remote sensing techniques and in situ data. The research was undertaken using Operational Land Imager (OLI) images on Landsat 8 and two SPOT images, because cloudy weather prevented the use of OLI images alone. This provided the information needed to perform a time series analysis of the lagoon. We also analyzed the processes that occur in the salt lagoon, characterizing the different spatio-temporal patterns of biophysical parameters. Special attention was given to the role of turbidity and chlorophyll-a levels in the Mar Menor ecosystem with regard to the programs of integral management of this natural space that receives maximum environmental protection. The objective of the work has been fulfilled by answering the questions of the managers: when did the water quality in the Mar Menor begin to change? What is happening in the lagoon? Is remote sensing useful for monitoring the water quality in the Mar Menor? The answers to these questions have allowed the generation of a methodology and monitoring system to track the water quality in the Mar Menor in real-time and space. The tracking system using satellite images is open to the incorporation of images provided by new multispectral sensors.This research was co-funded (80%) by the European Regional Development Fund (ERDF), through grant number FEDER 14-20-15

Application of “taxocene surrogation” and “taxonomic sufficiency” concepts to fish farming environmental monitoring. Comparison of BOPA index versus polychaete assemblage structure

“Taxocene surrogation” and “taxonomic sufficiency” concepts were applied to the monitoring of soft bottoms macrobenthic assemblages influenced by fish farming following two approaches. Polychaete assemblage evaluation through multivariate analysis and the benthic index BOPA were compared. Six fish farms along the Spanish Mediterranean coast were monitored. Polychaete assemblage provided a suitable picture of the impact gradient, being correlated with total free sulphides. BOPA did not support the impact gradient described by the polychaete assemblage, providing erroneous categorizations. The inclusion of several polychaete families, which were locally identified as indicative of affection to recalculate BOPA, resulted in an improved diagnosis and correlation with the impact gradient. Nevertheless, frequent misclassifications occurred. These results suggest that the structure of polychaete families, sulphides and granulometry conform an appropriate strategy for fish farming monitoring. Biotic indices need to be specifically designed for concrete activities, and regionally validated, because of the environmental plasticity of benthic invertebrates.This research was funded by the Spanish National Plans of Aquaculture (JACUMAR)

Multiplex RNA-based detection of clinically relevant MET alterations in advanced non-small cell lung cancer

We studied MET alterations in 474 advanced non-small-cell lung cancer (NSCLC) patients by nCounter, an RNA-based technique. We identified 3% with MET Δex14 mRNA and 3.5% with very-high MET mRNA expression, a surrogate of MET amplification. MET alterations identified by nCounter correlated with clinical benefit from MET inhibitors. Quantitative mRNA-based techniques can improve the selection of patients for MET-targeted therapies. MET inhibitors have shown activity in non-small-cell lung cancer patients (NSCLC) with MET amplification and exon 14 skipping (METΔex14). However, patient stratification is imperfect, and thus, response rates have varied widely. Here, we studied MET alterations in 474 advanced NSCLC patients by nCounter, an RNA-based technique, together with next-generation sequencing (NGS), fluorescence in situ hybridization (FISH), immunohistochemistry (IHC), and reverse transcriptase polymerase chain reaction (RT-PCR), exploring correlation with clinical benefit. Of the 474 samples analyzed, 422 (89%) yielded valid results by nCounter, which identified 13 patients (3%) with MET Δex14 and 15 patients (3.5%) with very-high MET mRNA expression. These two subgroups were mutually exclusive, displayed distinct phenotypes and did not generally coexist with other drivers. For MET Δex14, 3/8 (37.5%) samples positive by nCounter tested negative by NGS. Regarding patients with very-high MET mRNA, 92% had MET amplification by FISH and/or NGS. However, FISH failed to identify three patients (30%) with very-high MET RNA expression, among which one received MET tyrosine kinase inhibitor treatment deriving clinical benefit. Our results indicate that quantitative mRNA-based techniques can improve the selection of patients for MET-targeted therapies

Relaciones depredador-presa en organismos marinos, aposematismo en moluscos opistobranquios / Felipe Aguado Giménez ; director Arnaldo Aitor Marín Atucha.

Tesis-Universidad de Murcia.Consulte la tesis en: BCA. GENERAL. ARCHIVO UNIVERSITARIO. D 613.Consulte la tesis en: BCA. GENERAL. DEPOSITO. T.M-2067.CRAI CIENCIAS. Instituto Euromediterráneo del Agua. 594 AGU rel

Effect of Feed Delivery Rate and Pellet Size on Rearing Performance, Feed Wastage and Economic Profitability in Gilthead Seabream (Sparus Aurata) Ongrowing

Gilthead seabream (Sparus aurata) displays a particular eating behaviour that involves considerable oral manipulation and feed waste. We assess the influence of feed delivery rate and pellet size on seabream growth and size variability, feed wastage and economic profitability for a full production cycle. Batches of seabream were fed twice a day according to three different treatments (T1, T2, T3). T1 and T2 fish were fed with the same regime of pellet sizes: 2 mm pellets until the fish reached 0.1 kg, and 4 mm pellets from then on; the feeding rate in T1 was twice that of T2 (20 and 10 g min−1, respectively). T3 fish were fed with pellets of 2 mm until they reached 0.07 kg, with pellets of 4 mm until the fish reached 0.22 kg, and with 6 mm pellets from then on, with a feeding rate of 10 g min−1. T2 showed increased growth, low variability in fish size during the ongrowing and at harvest, less feed wastage both related to the delivery and the chewing behaviour, lower feed costs and improved profitability. Seabream wasted more feed during the second meal. Controlling the feeding process is essential to reduce wastage and increase profitability, which can be achieved by process monitoring and suitable feed pellet management

Aposematismo en los moluscos nudibranquios del género hypselodoris del mediterráneo : aprendizaje y memorización en el pez Thalassoma pavo /Felipe Aguado Giménez ; Arnaldo Marín Atucha, dir.

Tesis - Universidad de Murcia.Consulte la tesis en: BCA. GENERAL. ARCHIVO UNIVERSITARIO. TL 255