Intenziviranje procesa gajenja šarana u ruralnim oblastima severnog Vijetnama korišćenjem biljne hrane sa izvorom proteina različitog kvaliteta

U planinskom severnom Vijetnamu, ribnjačka akvakultura je važan deo tradicionalnog integrisanog sistema gajenja koji doprinosi proizvodnji proteina kao i finansijskoj dobiti. Akvakultura u Vijetnamu se najčešće zasniva na polikulturi belog amura sa belim tolstolobikom, sivim tolstolobikom, šaranom i nilskom tilapijom kao sekundarnim vrstama. Ova polikultura se odlikuje niskom produktivnošću od 1.5 t ribe po ha-1 a-1. Glavni razlozi za nizak stepen proizvodnje ribe u ovom region su: korišćenje hrane za ribe niskog kvaliteta (lišće, trava, nusproizvodi gajenja), nepoznata bolest sa visokom stopom smrtnosti belog amura i nekontrolisani protok vode kroz jezera što prouzrokuje zamućenost vode i gubitak mineralnih hranljivih materija za primarnu produkciju. Polu intenzivan system proizvodnje kao i promena načina nasađivanja u kome bi šaran bio najvažnija vrsta u sistemu polikulture može da doprinese većoj produktivnosti i profitabilnosti akvakulture ribnjaka u planinskom delu Vijetnama. Ove promene koje vode ka polu intenzivnoj polikulturi čija je glavna gajena vrsta šaran zahtevaju promenu u izvorima hrane kao i u proizvodnji hrane. Dok je hrana sa visokom energetskom vrednošću naširoko dostupna u region, izvori hrane bogate proteinima su ograničeni. Zbog toga je obavljeno istraživanje da bi se ustanovilo koji su lokalni izvori bogati proteinom najpogodniji da se koriste kao sastojci u dopunskoj ishrani šarana. Obavljena su ispitivanja u mrežnim kavezima u ribnjaku koji je bio nasađen sa tradicionalnim ribljim vrstama, sa gustinom nasada od 1.5 ribe po m2 i šaranom kao glavnom vrstom. Korišćeno je 16 mrežnih kaveza (veličine 2 x 2 x 2 m). Svaki kavez je nasađen sa po 5 primeraka mlađi šarana. Stajnjak preživara kao tradicionalno đubrivo stimulisala je dostupnost prirodne hrane. U tri mrežna kaveza, kao dodatna hrana za šarana korišćene su četiri izo-azotne hranljive smeše pripremljene sa lokalno dostupnim sastojcima sa visokim nivoom proteina (obrok od ribljeg brašna i soje, komercijalni koncentrat hrane za svinje, komercijalna hrana za mlađ ribe i ostaci od soje/tofu) i energije (obrok od kukuruza i obrok od manioke). Dnevna doza iznosila je 3% telesne mase riba. Tri mrežna kaveza nisu dobijala dodatnu hranu. 3 mrezna kaveza nisu dodatno hranjena i sluzila su kao kontrola. Na svakih 20 dana ribe u mrežnim kavezima su merene i količina hrane je usklađivana sa njihovom težinom; šarani iz šesnaestog mrežnog kaveza su izlovljeni radi analize crevinih sadržaja i zatim su ponovo nasađeni. U istom ritmu su praćeni parametri za merenje kvaliteta vode. Na isti način je praćena abundanca zooplanktona i zoobentosa. Uzorci ribe uzeti pre i posle testiranja su analizirani radi ustanovljavanja hemijskog sastava ribe. Hrana je takođe analizirana radi ustanovljavanja hemijskog sastava i sastava amino kiselina. Tradicionalni način đubrenja je stvarao životnu sredinu sa niskom ali vrlo promenljivom dostpupnošću zooplanktona (83 ± 49 mg m-2) i zoobentosa kao hrane (6.5 ± 7.5 mg m-2). Glavni izvor konzumirane prirodne hrane bio je zooplankton čija je veličina tela bila veća od 1mm. Pošto je gustina zooplanktona bila promenjiva, specifična stopa rasta šarana u određenim vremenskim intervalima u različitim tretmanima se mogla porediti sa dostupnošću prirodne hrane. Pozitivna korelacija između dostupne prirodne hrane i performansi rasta utvrđena je u svim slučajevima. Ipak, dostupnost prirodne hrane pod ovim režimom fertilizacije nije bio dovoljan da omogući neto rast šarana bez dodavanja hrane. Dodatno hranjnje je takođe bilo neophodno da bi se održala proizvodnja. Kada je reč o različitim vrstama dodavane hrane, ona bazirana na ostacima soje/tofu je bila najmanje efikasna. Sa ekonomske tačke gledišta, komercijalna hrana za životinje sa visokim nivoom proteina (komercijalna hrana za svinje i ribe) poboljšana lokalno proizvedenim sastojcima pokazala je bolju neto dobit nego hrana u čijem su sastavu kombinovani čisti sastojci (obrok od ribljeg brašna i zagrejane soje) s obzirom da su oni manje prisutni na lokalnom tržištu. Ipak, sva dodatna hrana nije imala dovoljnu količinu i kvalitet proteina da bi sama zadovoljila nivo proteina i esencijalnih amino kiselina koje su potrebne za šarana. Ovi rezultati navode na zaključak da pod dominantnim lokalnim uslovima, dodatna hrana lokalno napravljena od komercijalnih koncentrata hrane za životinja, sastojci bogati energijom mogu da dovedu do povećane proizvodnje ribe ukoliko se kombinuju sa prirodnom hranom koja je stalno dostupna. Ovo će omogućiti da se poveća udeo akvakulture u zaradi kao i u obezbeđenju hrane u domaćinstvima

Nutrient flow in improved upland aquaculture systems in Yen Chau, province Son La (Vietnam)

In South-East Asia, pond aquaculture plays an important role in the integrated agriculture aquaculture systems of small-scale farmers and contributes to their food security and income. In mountainous regions, aquaculture differs from aquaculture that is practiced in the lowland due to differences in climate and availability of feeds, fertilizers and water. In Northern Vietnam, the traditional aquaculture is a polyculture of 5-7 fish species. The macro-herbivorous grass carp (Ctenopharyngodon idella) is stocked as the main species. Common carp (Cyprinus carpio), silver carp (Hypophthalmichthys molitrix), bighead carp (Aristichthys nobilis), mrigal (Cirrhinus mrigala), mud carp (Cirrhinus molitorella) and Nile Tilapia (Oreochromis niloticus) are stocked as secondary species and are often insufficiently nourished by farm by-products. Manure is used by farmers as fertilizer for natural food resources. Ponds are managed as a constant water flow-through system. The inflowing water introduces soil particles eroded from the sloping fields of intensively cultured maize and cassava into the ponds, and cause high turbidity that limits both the primary and secondary production. The fish production of this system is low at about 1.5 ± 0.3 t ha-1 a-1 and is mainly limited by the poor quality of pond inputs, low availability of natural food resources, low oxygen production in the ponds and the occurrence of a species-specific disease that causes high mortality in grass carp. To improve the local fish production of small-scale farmers, changes in the traditional pond management were designed and tested in farmers ponds in the uplands of Northern Vietnam. These changes included the reduction of water flow through the ponds to reduce the introduction of eroded particles and reduce the turbidity. Chemical fertilizers were added to increase the productivity of natural food resources and encourage higher primary production. The disease-prone grass carp was replaced as the main species by common carp that command a similarly high price on the local markets. To feed the omnivorous common carp, supplemental pellet feeds based mainly on locally available resources were applied to the ponds. In a pond trial, the traditional and modified pond managements were compared for water quality parameters, availability of natural food resources, fish yields, nutrient utilisation efficiencies and monetary net benefit. In a 15N tracer experiment, the nitrogen dynamics in the natural food web in local ponds were compared under the two types of pond management. Acceptability of the modifications by local farmers was evaluated. In a net cage trial, the suitability of earthworm meal as a replacement for fishmeal in supplemental pellet feeds for common carp was tested. In another net cage trial, the effect of pesticide contaminated grass feeds on the feed intake and health condition of grass carp were tested. When compared with traditional pond management, the modified pond management was found to result in reduced water turbidity, deeper phototrophic zones, higher availability of natural food resources, higher primary production and higher fish yield. In addition, the small plankton benefited from the changes and allowed significantly higher growth rates of filter feeding fish. Common carp and grass carp had higher yields due to the changes. Under both types of pond management, nitrogen compounds were assimilated rapidly into the natural food web and there were high rates of sedimentation and re-mobilization of settled nitrogen from the pond bottom. Generally, the modifications to pond management were associated with increased nutrient utilisation efficiencies and resulted in higher net benefits and more stable pond culture conditions. It was shown that plant material from pesticide-treated fields should only be used cautiously as feeds for grass carp because pesticide residues reduce feed intake and adversely affect fish health. Low cost modifications were well accepted by the farmers. Application of supplemental feeds and chemical fertilisers, which required a continual monetary investment, were less well received. The better-educated farmers are more likely to further invest in aquaculture and might act as local adopters. To reduce the costs of feeds for common carp, earthworm has been shown to be suitable as a replacement for fishmeal in feeds. Vermiculture might therefore be a suitable additional farming activity in combination with the implementation of pond management modifications. Formation of fish farmer cooperatives might further increase the acceptability of innovations. The improvements to pond aquaculture that have been developed here may have a beneficial impact on fish production, food security and income of small-scale farmers in the uplands in South-East Asia if the information is suitably transferred through education programmes that train farmers in technologies that have been specially adapted to conditions in the uplands.Teich-Aquakultur ist ein wichtiger Teil der integrierten Landwirtschaft von Kleinbauern in Süd-Ost-Asien und trägt zur Nahrungs- und Einkommenssicherung bei. Klimatische Bedingung und Verfügbarkeiten von Futtermitteln, Düngemitteln und Wasser bedingen Unterschiede im Teich-Management im Berg- und Flachland. Unter traditionellem Teichmanagement in den Bergen von Nord-Vietnam werden Teiche mit 5-7 Fischarten besetzt. Der Graskarpfen (Ctenopharyngodon idella) ist die Hauptfischart, da dieser makroherbivore Fisch Blattmaterial verdauen kann. Schuppenkarpfen (Cyprinus carpio), Silberkarpfen (Hypophthalmichthys molitrix), Marmorkarpfen (Aristichthys nobilis), Mrigal (Cirrhinus mrigala), Schlammkarpfen (Cirrhinus molitorella) und Niltilapien (Oreochromis niloticus) sind Nebenfischarten und unzureichend gefüttert. Tierexkremente werden als Dünger für die Produktion von Phyto-, Zooplankton und Makrozoobenthos eingesetzt. Ständiger Wasserdurchfluss transportiert erodierte Bodenpartikel von den steilen Feldern in die Teiche und führt zu hoher Wassertrübung, welche die Produktion von Naturnahrung und Sauerstoff beeinträchtigt. Traditionelle Teiche haben daher mit 1.5 ± 0.3 Tonnen ha-1 a-1 nur einen geringen Fischertrag, welcher begründet ist durch die Verwendung von minderwertigem Futter und Dünger, durch die geringe Produktion von teichinterner Naturnahrung, durch geringe Sauerstoffversorgung und durch eine Graskarpfen-spezifische Krankheit. Um die lokale Fischproduktion zu erhöhen, wurden Veränderungen des traditionellen Teichmanagements entwickelt und getestet. Die Veränderungen bestanden in der Reduktion des Wasserdurchflusses, um so den Eintrag von erodierten Boden-Partikeln in den Teich und so die Trübung zu verringern. Kunstdünger wurde eingesetzt, um die Naturnahrung-Produktion und Sauerstoffgehalt zu verbessern. Anstatt mit krankheitsanfälligen Graskarpfen, wurden die Teiche mit dem omnivoren Schuppenkarpfen als Hauptfischart besetzt. Schuppenkarpfen wurden mit pelletiertem Futter aus hauptsächlich lokal vorhandenen Rohstoffen gefüttert. Das traditionelle und das modifizierte Teichmanagement wurden in Teichen von Kleinbauern in Nord-Vietnam verglichen. Hierbei wurden Wasserqualität, Verfügbarkeit von Naturnahrung, Fischertrag, Nährstoff-Effizienz und der finanzielle Ertrag getestet. In einem Stickstoff-Isotopen-Versuch wurden die zwei Aquakultur-Systeme auf die Dynamik von Stickstoff innerhalb des Naturnahrungsnetzes verglichen. Die Akzeptanz dieser Modifikationen wurde bei Kleinbauern mittels Interviews ermittelt. Die Eignung von Regenwürmern als Fischmehlersatz in pflanzenprotein-basiertem Futter für Schuppenkarpfen wurde in Netzkäfigen getestet. In einem weiteren Netzkäfigversuch wurden die Effekte von pestizid-kontaminiertem Blattmaterial auf die Futteraufnahme und den Gesundheitszustand von Graskarpfen untersucht. Im Vergleich zum traditionellen Teichmanagement führten die Modifikationen zu verringerter Wassertrübung, zu stärkeren phototrophen Schichten, zu erhöhten Verfügbarkeiten von Naturnahrung und zu erhöhten Primärproduktionen sowie höheren Fischerträgen. Die verstärkte Produktion kleinerer Plankter unter dem modifizierten Management resultierte in signifikant höherem Wachstum der plankton-filtrierenden Fischarten. Auch Schuppenkarpfen und Graskarpfen zeigten höhere Erträge und Wachstumsraten durch das bessere Fütterungsregime. Gelöster Stickstoff zeigte unter beiden Teichmanagements vergleichbar hohe Aufnahmeraten ins Naturnahrungsnetz, aber auch hohe Sedimentierungsraten und hohe Reaktivierungsraten von Stickstoff aus den Sedimenten. Generell führten die Modifikationen zu höherer Nährstoff-Effizienz sowie zu höheren und stabileren Teichkulturbedingungen und finanziellem Ertrag. Es hat sich gezeigt, dass Pflanzenmaterial von pestizid-behandelten Feldern nur mit Bedacht als Futter für Graskarpfen genutzt werden sollte, da die Pestizid-Rückstände sich negativ auf die Futteraufnahme und den Gesundheitszustand auswirken. Nur diejenigen Modifikationen, die mit geringem finanziellem Aufwand verbunden waren, zeigten hohe Akzeptanz bei Bauern. Der Einsatz von Pelletfutter und Kunstdünger wurde hingegen aufgrund der ständig nötigen Investition nur begrenzt von Kleinbauern angenommen. Es wird erwartet, dass besser gebildete Bauern in die neue Aquakultur investieren und so als lokale Innovationsverbreiter agieren werden. Regenwurm eignet sich gut als vor Ort erzeugbarer Fischmehlersatz in Futter für Schuppenkarpfen und könnte so deren Kosten zu reduzieren. Die Etablierung von Kooperativen von Bauern könnte die Akzeptanz dieser Technologien vergrößern. Es ist zu erwarten, dass die Anwendung der verbesserten Teichaquakultur eine Verbesserung der Fischproduktion, der Nahrungssicherung und des Einkommens der Kleinbauern in den Bergregionen Asiens bewirken wird. Hierzu sind Trainingsprogramme gefragt, in denen den Kleinbauern die lokal angepassten Verbesserungen der Aquakultur vermittelt werden

Putting small fish on the table: the underutilized potential of small indigenous fish to improve food and nutrition security in East Africa

Sub-Saharan Africa has a high prevalence of food insecurity. Small pelagic fish such as Silver cyprinid (Rastrineobola argentea) which is indigenous to Lake Victoria, can be a nutritious animal sourced food that contributes to a more nutrient dense diet. Potential sustainable catch of Silver cyprinid is estimated at 2 million tonnes yearly, which is four times the amount of the current catch. Whole sun-dried Silver cyprinid was purchased from several markets in Kenya and analysed for nutrient composition, microbial counts and metal content. The results show that utilizing the whole potential catch of Silver cyprinid would provide a significant daily source of vitamin B12, calcium, zinc and iron to the roughly 33 million people living in the Lake Victoria basin. Heavy metal concentration appears to be low, but other food safety aspects like microbial counts call for value chain improvements. We conclude that the underutilized potential of sun-dried Silver cyprinid could substantially contribute to fight malnutrition and food insecurity by providing an affordable nutrient dense animal sourced food to a large number of people. It also highlights the need to improve the value chains to increase the safety of these products.publishedVersio

Composition of nutrients, heavy metals, polycyclic aromatic hydrocarbons and microbiological quality in processed small indigenous fish species from Ghana: Implications for food security

The triple burden of malnutrition is an incessant issue in low- and middle-income countries, and fish has the potential to mitigate this burden. In Ghana fish is a central part of the diet, but data on nutrients and contaminants in processed indigenous fish species, that are often eaten whole, are missing. Samples of smoked, dried or salted Engraulis encrasicolus (European anchovy), Brachydeuterus auritus (bigeye grunt), Sardinella aurita (round sardinella), Selene dorsalis (African moonfish), Sierrathrissa leonensis (West African (WA) pygmy herring) and Tilapia spp. (tilapia) were collected from five different regions in Ghana. Samples were analyzed for nutrients (crude protein, fat, fatty acids, several vitamins, minerals, and trace elements), microbiological quality (microbial loads of total colony counts, E. coli, coliforms, and Salmonella), and contaminants (PAH4 and heavy metals). Except for tilapia, the processed small fish species had the potential to significantly contribute to the nutrient intakes of vitamins, minerals, and essential fatty acids. High levels of iron, mercury and lead were detected in certain fish samples, which calls for further research and identification of anthropogenic sources along the value chains. The total cell counts in all samples were acceptable; Salmonella was not detected in any sample and E. coli only in one sample. However, high numbers of coliform bacteria were found. PAH4 in smoked samples reached high concentrations up to 1,300 μg/kg, but in contrast salted tilapia samples had a range of PAH4 concentration of 1 μg/kg to 24 μg/kg. This endpoint oriented study provides data for the nutritional value of small processed fish as food in Ghana and also provides information about potential food safety hazards. Future research is needed to determine potential sources of contamination along the value chains in different regions, identify critical points, and develop applicable mitigation strategies to improve the quality and safety of processed small fish in Ghana.publishedVersio

Anchovy powder enrichment in brown rice-based instant cereal: a process optimization study using Response Surface Methodology (RSM)

There is a need for expanding the utilization of small fish as they constitute an undervalued and important source of protein and micronutrients in many developing countries suffering from micronutrient deficiencies. One way to increase consumption and health benefits is to add nutrient-rich fish meal into staple food ingredients. In this study, Response Surface Methodology (RSM) was applied to optimize the processing of an instant rice-based cereal enriched with anchovy powder. The Box-Behnken design was used to study the effect of principal processing variables (drying temperature, drum rotation speed, and slurry solids concentration) on product water activity, color, bulk density, and water solubility index. Viscosity, consistency, and cohesiveness of the reconstitute cereal were also evaluated. Empirical models were developed to describe the relationship between independent and dependent variables and showed regression coefficients (R2) ranging between 71% and 98%. Higher drying temperatures resulted in reduced water activity, darker product color, and lower consistency. While drum speed influenced (p < .05) product color and water-binding capacity, bulk density, and consistency of the reconstituted product was associated with slurry solids concentration. Optimal processing conditions obtained from the study were temperature of 130°C, drum speed of 9.3 rpm, and solids concentration of 20.5%. These conditions would be useful in the production of brown rice-based instant cereal enriched with anchovy powder with desired quality properties.publishedVersio

Implementing nature-based solutions for creating a resourceful circular city

Resource depletion, climate change and degradation of ecosystems are challenges faced by cities worldwide and will increase if cities do not adapt. In order to tackle those challenges, it is necessary to transform our cities into sustainable systems using a holistic approach. One element in achieving this transition is the implementation of nature-based solutions (NBS). NBS can provide a range of ecosystem services beneficial for the urban biosphere such as regulation of micro-climates, flood prevention, water treatment, food provision and more. However, most NBS are implemented serving only one single purpose. Adopting the concept of circular economy by combining different types of services and returning resources to the city, would increase the benefits gained for urban areas. The COST Action Circular City aims to establish a network testing the hypothesis that: ‘A circular flow system that implements NBS for managing nutrients and resources within the urban biosphere will lead to a resilient, sustainable and healthy urban environment’. In this paper we introduce the COST Action Circular City by describing its main objectives and aims. The paper also serves as introduction to the review papers of the Action's five Working Groups in this Special Issue

Gajenje slatkovodnih riba u centralnoj i istočnoj Evropi: potrebe za istraživanjem i razvojem

Gajenje slatkovodinih riba ima veoma važnu ulogu za stabilizaciju biodiversiteta, resursa podzemnih voda, klime regiona kao i za snabdevenost hranom u Centralnoj i Istočnoj Evropi. Velika konkurencija cena ribe na međunarodnom tržištu i promene u navikama ishrane ljudi pojačavaju pritisak na mala i srednja preduzeća u Centralnoj i Istočnoj Evropi koja se bave gajenjem ribe i mogu da ugroze predeo oko uzgojnih jezera. Da bi povećali vrednost svih karika u lancu proizvodnje slatkovodnih riba, naučnici i proizvođači su identifikovali uobičajene i potencijalne izazove. Da bi se procenile potrebe sektora akvakulture u centralnoj i istočnoj Evropi, sprovedeni su polu strukturirani intervjui sa proizvođačima i prerađivačima ribe i udruženjima u Poljskoj i Češkoj, u okviru projekta SIAD i FP7 EU projekta TRAFOON. Takođe su održane radionice sa istraživačima u sektoru akvakulture duž svake karike lanca proizvodnje riba u Centralnoj i Istočnoj Evropi. Različite interesne strane su identifikovale nekoliko izazova koji ometaju razvoj slatkovodne akvakulture u Centralnoj i Istočnoj Evropi. Razvoj akvakulture zahteva postojanje harmonizovanog regulativnog/pravnog okvira. Razmena znanja bi imala pozitivan uticaj na razvoj uniformnih standarda za održivost, i pomogla bi stvaranju pravnih procedura za izdavanje dozvola i licenci. Potrebno je izvršiti ekonomsku procenu usluga koje ekosistem ribnjaka pruža. Poboljšana tehnoligija koja je povoljna po životnu sredinu i sistemi za upravljanje kvalitetom u proizvodnji i preradi su neophodni da bi se obezbedila ustaljenija ponuda proizvoda od ribe viskog kvaliteta. Potrošači treba da budu bolje informisani o funkciji koju slatkovodna akvakultura i njeni proizvodi imaju za životnu sredinu. Da bi došlo do održivog razvoja sektora akvakulture i da bi se izgradilo poverenje javnosti, veoma je važno podstaći društvene inovacije koje su primenljive na pojedinačni sektor ili pojedinačnu teritoriju. Da bi došlo do održivog razvoja sektora slatkovodne akvakulture potrebno je razviti strategije makro regionalnog razvoja koje su prilagođene određenim tržištima, uslovima životne sredine, ponašanju potrošača, kulturi i tradiciji i koje nude potencijal za razvoj izvan granica jedne zemlje. Razvoj i adaptacija ključnih tehnologija potrebni su da bi se stabilizovala konkurentna i održiva proizvodnja i prerada ribe u čijoj su proizvodnji resursi efikasno iskorišćeni

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries