Algal dynamics in Lake Taihu, an example for shallow eutrophic lakes - from monitoring to modelling = Algendynamik im Taihu See, ein Beispiel für flache eutrophe Seen - vom Monitoring zur Modellierung

Algenblüten kommen häufig in eutrophen Seen vor und sind in vielen Ländern der Welt zu einem großen Problem geworden. Ein Beispiel hierfür ist der flache und eutrophe Taihu-See in China. Im Taihu-See treten Algenblüten oft mehrmals im Jahr auf und führen zu wachsenden Herausforderungen bei der Trinkwasserversorgung. Besonders die Trinkwasserkrise im Jahr 2007 war ein Weckruf für die Regierung, Zivilbevölkerung und Forscher, weshalb über die letzten Jahre verschiedenste Maßnahmen ergriffen wurden, um diesem Problem entgegenzuwirken. Die Ergebnisse dieser Maßnahmen sind jedoch bis heute nicht zufriedenstellend. Es ist daher dringend erforderlich, die Algendynamik im Taihu-See in den verschiedenen Jahreszeiten zu verstehen sowie die treibenden Faktoren der Algenblüten zu identifizieren, um auf Basis dieses Wissens angepasste Strategien und Lösungen zu entwickeln. Herkömmliche traditionelle Methoden zur Messung der Wasserqualität liefern in der Regel verzögerte Messdaten, die meist nie die Echtzeit-Situation eines Gewässers widerspiegeln. Zudem ignorieren die meisten Messverfahren vertikale Unterschiede der Wasserqualität, die insbesondere bei flachen und geschichteten Wasserkörpern einen großen Einfluss haben können. In dieser Studie wurde daher ein stationäres Online-Hochfrequenz-Multisensorsystem (BIOLIFT) eingesetzt, um die Veränderungen der Wasserqualität über die gesamte Wassersäule zu analysieren. Gleichzeitig wurde eine an den BIOLIFT angeschlossene Wetterstation genutzt, um meteorologische Echtzeit-Daten zu erfassen. Zur Messung der räumlichen Verteilung der Wasserqualität kam zudem ein Online-Multisensorsystem (BIOFISH) zum Einsatz, welches von einem Boot aus betrieben wurde. Parallel zu diesen Aktivitäten wurden Wasser- und Sedimentproben entnommen, um den Zustand und die Dynamik der im Taihu-See auftretenden Nährstoffe und Spurenmetalle zu charakterisieren. Auf Basis dieser Erkenntnisse wurde anschließend ein Simulationsmodell sowie ein konzeptionelles Modell erstellt, das in naher Zukunft dazu beitragen soll, ein Frühwarnsystem für das Wassermanagement am Taihu-See und den Betrieb von Trinkwasseranlagen zu entwickeln. Darüber hinaus wurden die ermittelten Online-Messdaten mit entsprechenden Daten des tieferen und weniger stark eutrophierten Westensees in Deutschland verglichen. Aus den Ergebnissen dieser Arbeit geht hervor, dass die Eutrophierung in Kombination mit geringen Wassertiefen vorteilhafte Bedingungen für das Algenwachstum schafft und auch die Remobilisierung von Metallen verstärkt. Es wurde ein Sauerstoffmangel beobachtet, der durch die Zersetzung von Algen und die Reduzierung des ins Wasser einfallenden Sonnenlichts durch Algenschäume verursacht wurde. Dieser Sauerstoffmangel führt zum Tod von Wassertieren und zur Verringerung der Artenvielfalt. Die Algendynamik, die Klima- und Witterungsbedingungen sowie die Wasserqualität (z.B. Nährstoffgehalte, Wassertemperatur, etc.) weisen außerdem starke jahreszeitliche Unterschiede auf. Selbst im flachen Taihu-See wurde im Sommer und zeitweilig im Herbst eine Stratifizierung beobachtet, was auf die Notwendigkeit eines vertikalen Tiefenprofil-Monitorings der Wasserqualität hinweist. Die vertikale Verteilung der Algen variiert in Abhängigkeit der Algenarten und wird durch windinduzierte Vermischungs- und Resuspensions-Ereignisse beeinflusst. Resuspensionsprozesse stellen eine der zentralen Nährstoffquellen dar und können insbesondere den benthischen Algen zu besseren Lebensbedingungen verhelfen sowie nahe der Wasseroberfläche auftretende Balualgenkolonien in tiefere Wasserschichten zurückbringen. Blaualgen sammeln sich im Sommer und Herbst, vor allem am Nachmittag, bevorzugt an der Wasseroberfläche an. Sonnenlicht ist wichtig für das Algenwachstum, jedoch führen Fluoreszenzlöschung- und/oder Photoinhibitionseffekte durch das starke Sonnenlicht zu einem Anstieg der Algenfluoreszenz in der Nacht, aufgrund der Erholung von Lichtschäden. Im Allgemeinen weisen flache Seen wie der Taihu eine bessere Lichtverfügbarkeit auf, allerdings kann diese auch leichter durch windbedingte Resuspensionsprozesse reduziert werden. Neben der Resuspension beeinflussen auch Blaualgenschäume die Lichtverhältnisse im Wasser. Grundsätzlich treten Blaualgenblüten vorzugsweise an warmen, sonnigen und ruhigen Tagen auf, wenn das Wasser außerdem einen hohen pH-Wert aufweist. Es besteht zudem eine höhere Wahrscheinlichkeit, dass Blaualgenblüten nach einem starken Windereignis auftreten. Blaualgen tolerieren auch Schwachlichtbedingungen, indem sie sich durch Auftriebsänderungen an die Wasseroberfläche bewegen. Daher kann präventive Arbeit im Vorfeld geleistet wurden. Mit den Ergebnissen dieser Studie wurde ein Modell entwickelt, mit dem auf Basis von hochfrequenten Multisensor- sowie Wetterdaten die Chlorophyll-a-Fluoreszenz-Veränderungsraten von Grün- und Kieselalgen sowie die Phycocyanin-Fluoreszenz von Blaualgen an der Wasseroberfläche simuliert werden können und sich darüber hinaus über einen kurzfristigen Zeitraum (2-3 Tage) vorhersagen lassen. Dies kann in Trinkwasseranlagen zur weiteren Entscheidungsfindung über notwendige Wasseraufbereitungsverfahren und die Menge des in verschiedene Einzugsgebiete gepumpten Rohwassers genutzt werden. Diese Dissertation zeigt neue Methoden zur Messung und Analyse der Wasserqualität in flachen und eutrophen Seen. Neben dem Taihu-See kann dieses System auch in anderen Oberflächengewässern (z.B. den Westensee) angewendet werden. Die Erkenntnisse und Modelle über die Wasser- und Algendynamik lassen sich zudem auf andere Seen in der Welt übertragen

Power asymmetry in conflict resolution with application to a water pollution dispute in China

© 2015. American Geophysical Union. All Rights Reserved. This is the peer reviewed version of the following article:Yu, J., Kilgour, D. M., Hipel, K. W., & Zhao, M. (2015). Power asymmetry in conflict resolution with application to a water pollution dispute in China. Water Resources Research, 51(10), 8627–8645, which has been published in final form at https://doi.org/10.1002/2014WR016257The concept of power asymmetry is incorporated into the framework of the Graph Model for Conflict Resolution (GMCR) and then applied to a water pollution dispute in China in order to show how it can provide strategic insights into courses of action. In a new definition of power asymmetry, one of the decision makers (DMs) in a conflict can influence the preferences of other DMs by taking advantage of additional options reflecting the particular DM's more powerful position. The more powerful DM may have three different kinds of power: direct positive, direct negative, or indirect. It is useful to analyze a model of a conflict without power asymmetry, and then to analyze a power-asymmetric model. As demonstrated by analysis of the water quality controversy that took place at the border separating the Chinese provinces of Jiangsu and Zhejiang, this novel conflict resolution methodology can be readily applied to real-world strategic conflicts to gain an enhanced understanding of the effects of asymmetric power.National Natural Science Foundation of China [71471087]Natural Sciences and Engineering Research Council of Canad

Tracer and Timescale Methods for Passive and Reactive Transport in Fluid Flows

Geophysical, environmental, and urban fluid flows (i.e., flows developing in oceans, seas, estuaries, rivers, aquifers, reservoirs, etc.) exhibit a wide range of reactive and transport processes. Therefore, identifying key phenomena, understanding their relative importance, and establishing causal relationships between them is no trivial task. Analysis of primitive variables (e.g., velocity components, pressure, temperature, concentration) is not always conducive to the most fruitful interpretations. Examining auxiliary variables introduced for diagnostic purposes is an option worth considering. In this respect, tracer and timescale methods are proving to be very effective. Such methods can help address questions such as, "where does a fluid-born dissolved or particulate substance come from and where will it go?" or, "how fast are the transport and reaction phenomena controlling the appearance and disappearance such substances?" These issues have been dealt with since the 19th century, essentially by means of ad hoc approaches. However, over the past three decades, methods resting on solid theoretical foundations have been developed, which permit the evaluation of tracer concentrations and diagnostic timescales (age, residence/exposure time, etc.) across space and time and using numerical models and field data. This book comprises research and review articles, introducing state-of-the-art diagnostic theories and their applications to domains ranging from shallow human-made reservoirs to lakes, river networks, marine domains, and subsurface flow

Resort Morphology: Chinese applications

This paper adopts a geographical perspective to understand the conceptual and theoretical issues of resort morphology. Resort morphology refers to “the forms and associated functions of a destination area and their development”. Resort towns are differentiated from other urban areas in terms of morphology because of their functional emphasis on tourism. The literature reflects the significant interest of European geographers in the morphological study of coastal resort towns. However, limited attention has been given to resort morphology in developing countries. It is argued that the complex of contextual factors that influence the morphological character of resorts needs to be considered and, furthermore, there is a great need to develop a systematic approach for investigating resort morphology. Based on a review of literature, this paper first introduces the contributions and implications of related research to the understanding of resort morphology: study of resort evolution, the Recreational Business District, urban morphology, and Geographic Information System (GIS) applications. Then, the situation of China is addressed because there is a striking contrast between the rate of change and increasing complexity of Chinese resorts and the very limited amount of studies from either western or Chinese scholars. A quantitative-qualitative mixed research approach is introduced to understand transitional resort morphology in China. It involves classifying land uses, building a descriptive and explanatory framework, creating form-function maps, and the analysis of morphological characteristics. Two study areas are selected for detailed examination: a coastal resort town, Sanya and a lake-based resort town, Wuxi. Morphological changes associated with key contextual factors influencing tourism and recreational development are analyzed in these places. A comparative discussion of Sanya and Wuxi indicates similarities between their development patterns of resort morphology and their present morphological features but significant differences in terms of history, evolutionary process, tourism resources, location and level of economic development. It is less helpful simply to define models applicable to distinct Chinese water-based resort towns than to identify similarities among them. Rules for resort study in the Chinese context are recommended and the characteristics of morphological transformation in a typical water-based resort town are summarized in view of resort development patterns. It is indicated that the morphology of a typical water-based resort cluster can be in large part a function of its recreational hinterlands (urban areas), and whether it is well-planned or more naturally developed. Finally, the relationships between contextual factors, tourism development, and resort evolution and resort morphology are interpreted in the context of Chinese water-based resort towns. The significance of morphological research on current as well as past resort structure for future planning and conservation activities is indicated. A systematic approach, which combines the morphological method, the functional method and the evolutionary method, is suggested to study resort morphology. By using resort evolution theory, it is indicated that resort morphology can be clearly identified and explored within a conceptual framework. This study also shows that GIS techniques are highly applicable in the study of resort morphology. This study indicates that water-based resort morphology in China is presently characterized by intensive land use and dense development, fast settlement expansion associated with growing vacation property development, and a generally clustered pattern of accommodation. Tourism planning in China has developed procedures and strategies with little consideration for the historical process. Therefore, this study has implications for making reasonable development strategies and efficiently implemented policies and plans. Academically, resort morphology is clarified in both Chinese and Western contexts. Also, common characteristics of Chinese water-based resort towns are summarized and phenomena generated from western studies are tested in the Chinese cases

Developing taxonomic and trait-based approaches for assessing and predicting macroinvertebrate responses to elevated fine sediments in the Tsitsa River and its tributaries, South Africa

Sedimentation of freshwater systems is one of the leading causes of water quality deterioration. The Mzimvubu River catchment, which includes the Tsitsa River and its tributaries, in the Eastern Cape is prone to elevated sediment impact due to dispersive soils that are easily erodible. In this study, taxonomy and trait-based approaches were used to assess the responses of macroinvertebrates to fine sediments in the Tsitsa River and its tributaries. Macroinvertebrates and environmental variables were sampled seasonally in winter, spring, summer and autumn of 2016 to 2018 in six selected sites, using the South African Scoring System version 5 as a collecting protocol. The sites were selected to represent a decreasing gradient of sediment influence from the highly impacted Sites 1 (Tsitsa upstream) 2 (Tsitsa downstream), and 3 (Qurana River) to moderately impacted Sites 4 (Millstream upstream) and 5 (Millstream downstream) and the least impacted Sites 6 (Pot River upstream), 7 (Little Pot River) and 8 (Pot River downstream), which were collectively referred to as the control sites. Analysis of basic physico-chemical variables, dissolved oxygen, pH, electrical conductivity, turbidity, total suspended solids, temperature and nutrients were undertaken seasonally over the study period. Sediments grain sizes were also analysed. All collected data were subjected to appropriate statistical tests – univariate and multivariate techniques. A fine-sediment-specific multimetric index was developed to monitor the impact of fine sediments on macroinvertebrate assemblages of the Tsitsa River and its tributaries. A total of 12 traits, resolved into 48 trait attributes, were selected to explore their distribution in relation to a fine-sediment stress gradient, and identify the trait-based signature of fine-sediment impact. A trait-based approach was then developed to classify South African macroinvertebrates into two groups: taxa that are potentially vulnerable to fine-sediment impact and those potentially resilient, based on the combination of traits possessed. Two-way analysis of variance (ANOVA) indicated that electrical conductivity, turbidity, embeddedness and total suspended solids were statistically significantly different between the sites. Apart from Dissolved oxygen, the remaining variables were statistically significantly lower at the control sites (P < 0.05). The two-way multivariate analysis of variance (MANOVA) indicated global significant differences between sites and seasons. The two-way MANOVA also revealed that the interaction between the sites and seasons were statistically significant. The MANOVA indicated global combined interactive effects across the sites for suspended fine-sediment grain sizes, two-way ANOVA, followed by a Tukey’s post-hoc test, was carried out to indicate where the significant differences lay. The one-way ANOVA results indicated that very fine sand, very coarse silt, medium silt, and fine silt were significantly higher at Tsitsa upstream, Tsitsa downstream, Qurana tributary that is at Millstream upstream, Millstream downstream and Control sites. The rest of the grain sizes did not differ statistically between the sites. In terms of the settled sediment grain sizes, the volumetric analysis did not show considerable differences across the sites. Settled fine-sediment grain sizes were evenly distributed across the sites. Statistically, MANOVA results indicated no significant differences across sites or across seasons. The developed Sediment Multimetric Index indicated that the sites in the Tsitsa River and those in the Qurana River were highly sedimented during the wet season, but became moderately sedimented during the dry season, indicating that the index responded to seasonality. The sediment multimetric index indicated that the control sites were less sedimented during both the wet season and dry seasons, suggesting minimal seasonal effects at the control sites. Traits such as an exposed and soft body, collector-filterers, shredding, feeding on coarse particulate organic matter and a high sensitivity to dissolved oxygen were identified as fine- sediment-sensitive indicator traits. Identified fine-sediment-tolerant traits and ecological preferences included complete sclerotisation, a cased/tubed body, a preference for fine particulate organic matter, a high tolerance to dissolved oxygen depletion, and climbing and skating behaviours. Regarding the trait-based approach followed for classifying macroinvertebrates into vulnerable taxa and resilient taxa, the results revealed that the relative abundance and richness of the vulnerable taxa decreased predictably along the increasing gradient of sediment impact. However, the relative abundance and richness of resilient taxa showed no marked response to the impact of an increasing gradient of fine sediments. Overall, the present study makes a contribution to the complementary application of trait-and taxonomy-based approaches to freshwater biomonitoring. The trait-based approach enables predictions to be made and tested based on the mechanistic understanding of the mediating roles of traits in organism- environment interaction. A fundamental challenge, which showcases the limitation of the current study, is the sparse trait data on Afrotropical macroinvertebrates at the species or generic levels. In this regard, the iv trait-based approaches developed here were the family level instead of species or genus. This is the first study in South Africa to develop explicit trait-based indicators of elevated fine sediments as well as an approach for predicting macroinvertebrate vulnerability and resilience to fine-sediment effects, thus advancing the science and practice of freshwater biomonitoring.Thesis (PhD) -- Faculty of Science, Institute for Water Research, 202

Developing taxonomic and trait-based approaches for assessing and predicting macroinvertebrate responses to elevated fine sediments in the Tsitsa River and its tributaries, South Africa

Sedimentation of freshwater systems is one of the leading causes of water quality deterioration. The Mzimvubu River catchment, which includes the Tsitsa River and its tributaries, in the Eastern Cape is prone to elevated sediment impact due to dispersive soils that are easily erodible. In this study, taxonomy and trait-based approaches were used to assess the responses of macroinvertebrates to fine sediments in the Tsitsa River and its tributaries. Macroinvertebrates and environmental variables were sampled seasonally in winter, spring, summer and autumn of 2016 to 2018 in six selected sites, using the South African Scoring System version 5 as a collecting protocol. The sites were selected to represent a decreasing gradient of sediment influence from the highly impacted Sites 1 (Tsitsa upstream) 2 (Tsitsa downstream), and 3 (Qurana River) to moderately impacted Sites 4 (Millstream upstream) and 5 (Millstream downstream) and the least impacted Sites 6 (Pot River upstream), 7 (Little Pot River) and 8 (Pot River downstream), which were collectively referred to as the control sites. Analysis of basic physico-chemical variables, dissolved oxygen, pH, electrical conductivity, turbidity, total suspended solids, temperature and nutrients were undertaken seasonally over the study period. Sediments grain sizes were also analysed. All collected data were subjected to appropriate statistical tests – univariate and multivariate techniques. A fine-sediment-specific multimetric index was developed to monitor the impact of fine sediments on macroinvertebrate assemblages of the Tsitsa River and its tributaries. A total of 12 traits, resolved into 48 trait attributes, were selected to explore their distribution in relation to a fine-sediment stress gradient, and identify the trait-based signature of fine-sediment impact. A trait-based approach was then developed to classify South African macroinvertebrates into two groups: taxa that are potentially vulnerable to fine-sediment impact and those potentially resilient, based on the combination of traits possessed. Two-way analysis of variance (ANOVA) indicated that electrical conductivity, turbidity, embeddedness and total suspended solids were statistically significantly different between the sites. Apart from Dissolved oxygen, the remaining variables were statistically significantly lower at the control sites (P < 0.05). The two-way multivariate analysis of variance (MANOVA) indicated global significant differences between sites and seasons. The two-way MANOVA also revealed that the interaction between the sites and seasons were statistically significant. The MANOVA indicated global combined interactive effects across the sites for suspended fine-sediment grain sizes, two-way ANOVA, followed by a Tukey’s post-hoc test, was carried out to indicate where the significant differences lay. The one-way ANOVA results indicated that very fine sand, very coarse silt, medium silt, and fine silt were significantly higher at Tsitsa upstream, Tsitsa downstream, Qurana tributary that is at Millstream upstream, Millstream downstream and Control sites. The rest of the grain sizes did not differ statistically between the sites. In terms of the settled sediment grain sizes, the volumetric analysis did not show considerable differences across the sites. Settled fine-sediment grain sizes were evenly distributed across the sites. Statistically, MANOVA results indicated no significant differences across sites or across seasons. The developed Sediment Multimetric Index indicated that the sites in the Tsitsa River and those in the Qurana River were highly sedimented during the wet season, but became moderately sedimented during the dry season, indicating that the index responded to seasonality. The sediment multimetric index indicated that the control sites were less sedimented during both the wet season and dry seasons, suggesting minimal seasonal effects at the control sites. Traits such as an exposed and soft body, collector-filterers, shredding, feeding on coarse particulate organic matter and a high sensitivity to dissolved oxygen were identified as fine- sediment-sensitive indicator traits. Identified fine-sediment-tolerant traits and ecological preferences included complete sclerotisation, a cased/tubed body, a preference for fine particulate organic matter, a high tolerance to dissolved oxygen depletion, and climbing and skating behaviours. Regarding the trait-based approach followed for classifying macroinvertebrates into vulnerable taxa and resilient taxa, the results revealed that the relative abundance and richness of the vulnerable taxa decreased predictably along the increasing gradient of sediment impact. However, the relative abundance and richness of resilient taxa showed no marked response to the impact of an increasing gradient of fine sediments. Overall, the present study makes a contribution to the complementary application of trait-and taxonomy-based approaches to freshwater biomonitoring. The trait-based approach enables predictions to be made and tested based on the mechanistic understanding of the mediating roles of traits in organism- environment interaction. A fundamental challenge, which showcases the limitation of the current study, is the sparse trait data on Afrotropical macroinvertebrates at the species or generic levels. In this regard, the iv trait-based approaches developed here were the family level instead of species or genus. This is the first study in South Africa to develop explicit trait-based indicators of elevated fine sediments as well as an approach for predicting macroinvertebrate vulnerability and resilience to fine-sediment effects, thus advancing the science and practice of freshwater biomonitoring.Thesis (PhD) -- Faculty of Science, Institute for Water Research, 202

Estudo comparativo das características físico-químicas e sensoriais de polvo, pescada, cachucho e barracuda comercializados em Faro e em Luanda

Dissertação de mestrado, Tecnologia de Alimentos, Instituto Superior de Engenharia, Universidade do Algarve, 2016Nos últimos anos a segurança e a qualidade dos alimentos tornaram-se questões de grande preocupação no mundo. O pescado é um alimento de elevado valor nutricional e de grande aceitação por parte dos consumidores. Contudo, por ser um alimento rapidamente perecível, os produtores têm tido especial atenção com relação a qualidade do mesmo, tendo em conta o importante papel que desempenha na aceitação por parte dos consumidores, no comércio internacional para muitos estados costeiros, assim como na saúde humana. Assim sendo, avaliação da frescura do pescado é feita mediante inspeções microbianas, medições físicas, medições químicas e avaliação sensorial. Neste contexto, o presente trabalho tem como finalidade avaliar a frescura do polvo, do cachucho e da pescada comercializados em Faro e do polvo, do cachucho e da barracuda comercializados em Luanda através de métodos físicos, químicos e sensoriais, bem como determinar a composição química das referidas espécies e comparar a composição química do polvo e do cachucho comercializados em Faro e em Luanda. A comparação dos espécimes foi feita pelo uso da análise estatística t-student. Com base nas análises químicas e na análise estatística foi possível verificar as diferenças estatísticas entre a composição química das espécies comercializadas em Faro e em Luanda. O parâmetro que mais se diferenciou foi o teor de cloretos (0,5% vs. 1,00%) do cachucho comercializado em Luanda e Faro e do polvo (1,4% vs. 0,8 %) de Luanda e de Faro. O cachucho de Luanda apresentou maior teor proteico em relação ao cachucho de Faro (18,3 % vs, 14,4%). As análises físico-químicas e sensórias mostraram que as espécies apresentavam um elevado grau de frescura. A análise estatística de correlação Rho Spearman demonstrou que o TBARS, a CRA e a aw têm alta correlação com a análise sensorial (odor, firmeza e a cor da pele), o que quer dizer que estes parâmetros são mais adequados para a determinação da frescura das espécies analisadas.In recent years the safety and quality of food have become issues of great concern worldwide. The fish is a high nutritional value of food and wide acceptance by consumers. However, being a highly perishable food, producers have had special attention with respect to quality of it, taking into account the important role it plays in acceptance by consumers, in international trade for many coastal states, as well as on human health. Therefore, fish freshness evaluation is made by microbial inspections, physical measurements, chemical measurements and sensory evaluation. In this context, this study aims to assess the freshness of the octopus, cachucho and hake marketed in Faro and octopus, cachucho and barracuda marketed in Luanda through physical, chemical and sensory methods, and to determine the chemical composition of such species and to compare the chemical composition of octopus and cachucho marketed in Faro and Luanda. Comparison of the specimens was taken by use of the t-student statistical analysis. On the basis of chemical analyses, it was possible to observe statistically significant differences between the chemical composition of species marketed in Faro and in Luanda. The parameter that differed most was the chloride content (0.5% vs. 1.00%) of cachucho marketed in Luanda and Faro and octopus (1.4% vs. 0.8%) of Luanda and Faro. The cachucho from Luanda showed higher protein content compared to cachucho in Faro (18.3% vs 14.4%). The physical-chemical and sensory analysis showed that the specimens were at high level of freshness. Statistical analysis Rho Spearman correlation showed that TBARS, CRA and aw are highly correlated with the sensory attributes (odor, firmness and skin color), which means that these parameters are more suitable for the determination of freshness the species analyzed