Sarnissa-french-aquaculture October 2015

sarnissa-french-aquaculture@lists.stir.ac.uk

7 participants
18 discussions

Large-scale tilapia project driving aquaculture development in Ivory Coast Projet de tilapia à grande échelle conduite développement de l'aquaculture en Côte-d'Ivoire

by William Leschen

Large-scale tilapia project driving aquaculture development in Ivory Coast - En francais au dessous Just up on SARNISSA daily updated Facebook site https://www.facebook.com/sarnissaafrica/?fref=ts For latest news, media, publications, videos, employment , funding, investment ........ See more at: http://advocate.gaalliance.org/large-scale-tilapia-project-driving-aquacult… http://advocate.gaalliance.org/large-scale-tilapia-project-driving-aquacult… Ed : Interesting the strain of niloticus they are using in Cote D Ivoire .... For our Ghanaian SARNISSA Followers from all the different sectors to reply - Would it be possible to use this strain in Ghana on the lake or elsewhere in earthponds ? It would be good Jerome also if you can send in any further information on the growth rates of this strain - in the cages in Cote D Ivoire and also if you have growth rates in earthponds - these are all mono sex tilapia ? % all male rate ? - thank you Best wishes Will Projet de tilapia à grande échelle conduite développement de l'aquaculture en Côte-d'Ivoire Voir plus: http://advocate.gaalliance.org/large-scale-tilapia-project-driving-aquacult… http://advocate.gaalliance.org/large-scale-tilapia-project-driving-aquacult… Ed: intéressant la souche de niloticus qu'ils utilisent en Cote D Ivoire .... Pour nos Abonnés ghanéenne SARNISSA de tous les différents secteurs pour répondre - Serait-il possible d'utiliser cette souche au Ghana sur le lac ou ailleurs dans earthponds? Il serait bon Jérôme également si vous pouvez envoyer toute information complémentaire sur les taux de cette souche de croissance - dans les cages en Côte d'Ivoire et aussi si vous avez des taux de croissance dans earthponds - merci Amicalement Will Institute of Aquaculture, University of Stirling UK www.aqua.stir.ac.uk<http://www.aqua.stir.ac.uk/> Follow Daily updated Facebook sites (news, publications, videos, employment, funding, investment and other) for: Inst of Aquaculture Stirling Scotland UK<https://www.facebook.com/pages/Institute-of-Aquaculture-Stirling-Scotland-U…> SARNISSA African Aquaculture Network <https://www.facebook.com/sarnissaafrica?ref=hl> Aquaculture Enterprise Malawi<https://www.facebook.com/pages/Aquaculture-Enterprise-Malawi/57280560286237…> SEAT Sustaining Ethical Aquaculture Trade Asia (SEAT) <https://www.facebook.com/SEATGlobal?ref=hl> <http://www.aqua.stir.ac.uk/>

9 years, 1 month

FW: Probiotics ? Pond fertilisation ……..

by William Leschen

En francais au dessous From: Warren A. Turner [mailto:warren2@tilapiathai.com] Sent: 27 October 2015 02:03 To: William Leschen; 'Anetekhaimartins' Cc: sarnissa-french-aquaculture Mailing List Subject: RE: Probiotics ? Pond fertilisation …….. Hi All, I have always been skeptical of probiotics added to the water. I recently had a meeting with a guy who knows a lot about them since he wanted to approach our customers to sell them. The bacteria is Bacillus subtilis which can live aerobically or anaerobically. They call this ability facultative. They are supplied as spores (not cysts) which multiply rapidly and then reach a peak after I think 2 days and then gradually drop off to nothing in 18 days. The reason he told me is like cells in your body, as you get older, even though there is no change in your DNA and your cells are always dividing and replacing each other, they become old. I guess you need to go back to a stem cell to get new ones again. Like a babies skin compared to an old person. I guess a spore is like an egg cell. This is why you have to add on a weekly basis. Anyway I haven’t got time to go into this too much. If you put probiotic in feed you don’t need to put it in the pond, as it comes out in the faeces. The benefits are supposed to be digestion and removal of faeces and uneaten feed on the bottom. I just did a trial and added probiotic to a pond on a weekly basis. I took bottom core samples from 2 points twice per week. There did seem to be a reduction in the thickness and the black colour reduced slightly to a very dark brown. My branch in Nakhon Pathom province in Thailand uses this probiotic and says the ponds don’t smell when they drain them. I did once do a trial over a year in which I used 9 ponds. 3 control, 3 a probiotic called Ecobac and 3 with a product called Aquafresh. I did 5 crops of sex reversal in each pond and Aquafresh gave 10% better survival and Ecobac 5% over the whole period. The guy from the company says you will notice much more benefit if you are raising fish more intensively. If you are like us and keep densities fairly low (over the whole pond that is) and drain ponds regularly you might not notice any difference. Like Will said, there is no replacement for good husbandry. That should always come first. Best regards Warren Salut tout le monde, Je l'ai toujours été sceptique des probiotiques ajoutés à l'eau. Je récemment eu une réunion avec un gars qui sait beaucoup de choses sur eux depuis qu'il voulait approcher nos clients pour leur vendre. La bactérie est Bacillus subtilis qui peuvent vivre aérobie ou anaérobie. Ils appellent cette capacité facultative. Ils sont fournis sous forme de spores (pas kystes) qui se multiplient rapidement et atteignent un pic après je pense que 2 jours et ensuite tomber graduellement à rien dans 18 jours. La raison qu'il m'a dit est comme cellules de votre corps, que vous vieillissez, même si il n'y a aucun changement dans votre ADN et vos cellules sont toujours diviser et remplacer l'autre, ils deviennent vieux. Je suppose que vous avez besoin de revenir à une cellule souche pour obtenir à nouveau de nouveaux. Comme une peau de bébé par rapport à une personne âgée. Je suppose une spore est comme un ovule. Voilà pourquoi vous devez ajouter sur une base hebdomadaire. Quoi qu'il en soit, je ne l'ai pas eu le temps d'aller dans ce trop. Si vous mettez probiotique dans l'alimentation que vous ne devez pas le mettre dans l'étang, comme il vient dans les fèces. Les avantages sont censés être la digestion et l'élimination des matières fécales et les aliments non consommés sur le fond. Je viens de faire un procès et a ajouté probiotique à un étang sur une base hebdomadaire. Je pris des échantillons de carottes de fond à partir de 2 points fois par semaine. Il ne semble y avoir une réduction de l'épaisseur et la couleur noire légèrement réduit à un brun très foncé. Mon succursale dans la province de Nakhon Pathom en Thaïlande utilise ce probiotique et dit les étangs ne sentent pas quand ils les égoutter. Je ne le fais une fois un procès plus d'un an que je l'habitude 9 étangs. 3 contrôle, 3 un probiotique appelé ECOBAC et 3 avec un produit appelé Aquafresh. Je l'ai fait 5 cultures de changement de sexe dans chaque étang et Aquafresh donné 10% de mieux survie et ECOBAC 5% sur l'ensemble de la période. Le gars de la compagnie dit, vous remarquerez beaucoup plus d'avantages si vous élevez des poissons plus intensive. Si vous êtes comme nous et garder densités relativement faible (sur l'ensemble du bassin qui est) et de drain étangs régulièrement, vous pourriez ne pas remarqué une différence. Comme Will dit, il n'y a pas de remplacement pour un bon élevage. Cela devrait toujours venir en premier. Cordialement Warren From: Sarnissa-african-aquaculture [mailto:sarnissa-african-aquaculture-bounces@lists.stir.ac.uk] On Behalf Of William Leschen via Sarnissa-african-aquaculture Sent: Monday, October 26, 2015 5:52 PM To: 'Anetekhaimartins' Cc: sarnissa-african-aquaculture Mailing List; sarnissa-french-aquaculture Mailing List Subject: Probiotics ? Pond fertilisation …….. Probiotics ? Pond fertilisation …….. Read through thread - En francais au dessous [cid:image001.jpg@01D11094.EB841080] Dear Anetekhai I didn’t recommend probiotics …. ! Murali did - one of our fish farming members - I am posting your reply up on the forum to see if others have any thoughts or ideas about using and paying for probiotics to fertilise their ponds for tilapia catfish – their positive and or negative effects? Personally I don’t think its relevant here as they are normally used in Asia for other purposes particularly related to health on commercial shrimp farms - Note in Nigeria as you are probably aware they (and their like) are increasingly being added as feed supplements for the Clarias hatchery and juveniles without in a lot of cases in my opinion the fish farmers actually knowing what they are buying and using – also in Nigeria “Tonics” for pond water quality now been openly sold off the shelf (at high prices) in bottles and packets by pharmaceutical companies which again the fish farmers have little idea what the active ingredients are and how they should work – or I should say IF they work . With respect For pond fertilisation I would read carefully the words of the people who have been doing it years in Asia and some in Africa - and realise that this is something that cannot just come out of a text book or be remedied by buying a packet or bottle from a pharmacist – is site specific and has to come from careful observation and years of experience…… Best wishes Will From: Anetekhaimartins [mailto:anetekhaimartins@gmail.com] Sent: 26 October 2015 07:30 To: William Leschen Subject: RE: FW: Semi-intensive ponds Optomimum fetilsation and maintenance Mozambique Good day William, I just read one of your responses in which you recommended probiotic. I have also observed some farmers bringing into Nigeria some probiotics for use. My fear is that there may be negative impact on the long run. Are you aware of any such report? Can you educate me on any negetive impact. Thank you. Anetekhai martins Cher Anetekhai Je ne recommande pas les probiotiques .... ! Murali a fait - l'un de nos membres de pisciculture - je poster votre réponse sur le forum pour voir si d'autres ont des pensées ou des idées sur l'utilisation et le paiement des probiotiques pour fertiliser leurs étangs du tilapia poisson-chat? Personnellement, je ne pense pas que son compte ici, car ils sont normalement utilisés en Asie à d'autres fins liées notamment à la santé sur les élevages de crevettes commerciaux - Note au Nigeria que vous êtes probablement au courant qu'ils (et leurs semblables) sont de plus en plus ajoutés comme compléments alimentaires pour l'écloserie de Clarias et mineurs sans en beaucoup de cas, à mon avis, les pisciculteurs sachant réellement ce qu'ils achètent et utilisent - aussi au Nigeria "toniques" pour la qualité de l'eau de l'étang désormais ouvertement vendus (à des prix élevés) dans des bouteilles et des paquets par les compagnies pharmaceutiques qui encore une fois les pisciculteurs ont peu idée de ce que les ingrédients actifs sont et comment ils doivent travailler - ou devrais-je dire si elles travail . Avec respect pour la fertilisation des étangs Je voudrais lire attentivement les paroles des gens qui ont fait ça années en Asie et dans certains pays africains - et de réaliser que ceci est quelque chose qui ne peut pas juste de sortir d'un livre de texte ou être remédié par un achat d'un paquet - est spécifique au site et doit venir de l'observation et des années d'expérience attention ...... Amicalement Will De: Anetekhaimartins [mailto: anetekhaimartins(a)gmail.com<mailto:anetekhaimartins@gmail.com>] Envoyé 26 Octobre ici à 2015 7:30 Pour: William Leschen Sujet: Re: FW: étangs semi-intensifs fetilsation Optomimum et l'entretien du Mozambique Bonjour William, Je viens de lire un de vos réponses dans lequel vous recommandé probiotique. Je ai également observé certains agriculteurs mettant en Nigeria certains probiotiques pour l'utilisation. Ma crainte est qu'il peut y avoir des répercussions négatives sur le long terme. Etes-vous conscient d'un tel rapport? Pouvez-vous me renseigner sur tout impact negetive. Merci. Martins Anetekhai -------- Original message -------- From: William Leschen via Sarnissa-african-aquaculture <sarnissa-african-aquaculture(a)lists.stir.ac.uk<mailto:sarnissa-african-aquaculture@lists.stir.ac.uk>> Date: 24/10/2015 1:55 PM (GMT+01:00) To: sarnissa-african-aquaculture Mailing List <sarnissa-african-aquaculture(a)lists.stir.ac.uk<mailto:sarnissa-african-aquaculture@lists.stir.ac.uk>> Subject: FW: Semi-intensive ponds Optomimum fetilsation and maintenance Mozambique From: chnmurali(a)gmail.com<mailto:chnmurali@gmail.com> [mailto:chnmurali@gmail.com] Sent: 24 October 2015 10:12 To: William Leschen Subject: Re: Semi-intensive ponds Optomimum fetilsation and maintenance Mozambique Dear William Looking at the parameters sent by Chris it clearly says that pond is over blooming since the oxygen levels are over saturated. He mentioned total alkalinity as 180 but did not mention about carbonate and bicarbonate alkalinity or pH, I assume that pH will be definitely high in the evening times with high carbonates and also more CO2 in the early hours. This condition will subject the fish to extreme stress and sometimes mass mortality in early hours. Dilluting pond with fresh water also not a solution, the more you flush the more it blooms if the pond has accumulated organic load and high nitrogen levels. My suggestion is to drain surface water in the mid afternoon when plankton will be floating on surface at higher density and top up water in the night time. Add Sodium carbonate in the early hours to reduce CO2 and not to rise pH, never go to Calcium based liming products till he get stabilized pH. I assume that pH fluctuation at this stage might be more than 1, it's has to come down to 0.5 then only we can say buffering is good. Either organic or inorganic fertiliser he has to make a slurry, and broadcast that in water to avoid organic load entering pond when using organic fertiliser or inorganic fertiliser helping growth of macrophytes. He should not stop feeding but reduce it to half until bloom is stabilised. Start using Probiotics which can take care of water quality. With Regards Murali Sent from my iPhone On 24 Oct 2015, at 8:03 AM, William Leschen via Sarnissa-african-aquaculture <sarnissa-african-aquaculture(a)lists.stir.ac.uk<mailto:sarnissa-african-aquaculture@lists.stir.ac.uk>> wrote: Thanks Warren - Manual contains nice review of pond fertilisation Hi Chris, Farmers do this by looking at the water colour and fertilising in response to this. There will tend to be a need to increase fertilisation over time as the fish grow. A dried pond just filled with go green easily due to good light penetration. Turbidity reduces light penetration which phytoplankton depend on. Earthen ponds get more turbid with time. Soil obviously has a big effect. Cloudy weather also. Don't be tempted to keep putting in more fertiliser if the pond doesn't go green, particularly if the weather is very cloudy all day. As soon as you get a sunny day it will change to pea soup. The recommended amount found by research at AIT is 4 kg of nitrogen and 1-2 kg of phosphorous per ha per day. Of course you need to know how much N and P are in any organic ferilisers. Inorganic fertiliser is easier to calculate. %N is quoted on the bag, but P is quoted as P2O5 and to calculate how much P in a kg you need to allow of the oxygen. 1 mole of P is 30.974g and a mole of oxygen is 15.999. So a mole of P2O5 would weigh 109.918. 61.948g of this is P which is equivalent to 56.36% In 1 kg of16-20-0 fertiliser (N-P-K) you have 160g of N and 200 x 56.36% = 112.7g P. See this link to a pond rearing manual I put on the website = http://tilapiathai.com/asset/NILE%20TILAPIA%20CULTURE%20IN%20EARTHEN%20POND… If you are using inorganics and are adding N and P only, you might want to try adding K. For example, we used to use 16-20-0 which we apply at 187 kg/ha/week. We now use 15-15-15 at the same rate, as we find it gets the pond green better I assume as K is limiting sometimes. If the pond doesn't go green we can try adding dolomite which contains magnesium. If you are adding some organics, then you won't have deficiency of elements required in small amounts. Secchi disk measurements will relate not just to phytoplantkton levels, but all suspended solids. Chlorophyll levels can be measured, but it really isn't difficult to do it by eye. Remember that any feed going in the pond is also adding N and P. Best Warren On Thu, Oct 22, 2015 at 8:12 PM, William Leschen <william.leschen(a)stir.ac.uk<mailto:william.leschen@stir.ac.uk>> wrote: Dear Chris Thanks I will post this up on the sarnissa forum but am also copying to - rather than limnologists – much better in my opinion those who have applied and practiced hands on over many years - Peter (Edwards – you’ve already corresponded with him) and also Warren Turner in Thailand as Warren at Namsai has worked out protocols over the years for optimum fertilisation of his ponds and also maintenance/balance of blooms over longer prod time periods - noting also though that as you know the local pond substrate , water quality at inflow go to make up very specific water chemistry for particular sites – each one different – also their particular buffering capacity towards more stable algal bloom production over time - I think I realised a while ago on visits to long well established greenwater pond systems China exactly how much of a skill and an art this is – - and something that is very much experience based not just getting figures and dose rates for organic and inorganic from text books. Ive also copied to Mark Amechi in Ghana as his pond hatchery site through a nos of French origin site managers has developed greenwater pond systems for them that work over the years - Also for you might be worth looking to trial 1-2 ponds from scratch seeding of specific algal species ?If you haven’t already I would recommend looking at some of Claude Boyds now old but still very valid publications from Auburn - books but also plenty of papers Eg http://www.alibris.com/Dynamics-of-Pond-Aquaculture-Claude-E-Boyd/book/1847… http://www.amazon.com/By-Claude-Boyd-Aquaculture-Management/dp/B008WDSSL0 Best wishes Will From: Chris Schnell [mailto:cwschnell@gmail.com<mailto:cwschnell@gmail.com>] Sent: 22 October 2015 13:36 To: William Leschen Subject: Semi-intensive ponds Dear Will, If you have a limnologist in the forum, he could possibly help me resolve my questions. Or, anyone with experience of growing tilapia in mud ponds would most probably be able to clarify things. Producing tilapia in semi-intensive mud ponds using algae and supplementary feed is not all that easy as it sounds, especially when you start having problems with fertilizing the water. What is the best way to measure primary production of algae? Does oxygen levels tell the whole story, or does one also look at the green / grey colour of the water? Or are there better methods? My problem started with overdosing. It seems as if it takes a long time to dilute one’s nutrients and algae once you have a bloom with a reading of less than 15 cm on the Secchi disk. For financial reasons I did not want to remove water from my pond after over dosing, but now I keep on adding more water and the Secchi readings do not go up. I cut down dramatically in adding new fertilizer. This makes me worry that the algae in the pond could be dead or just floating solids and that the primary production, that serves as feed for the tilapia, is not sufficient. My ponds are around 1 hectare in size and the depth varies between 400mm and 900mm. Temperature is 27°C at the bottom and 29°C at the surface. Oxygen at 12h00 is 12.5 ml/l at the surface and 9.5 ml/l at a depth of 900 mm. I fertilise with dry cow manure, Urea and DAP. Total alkalinity is around 180. Best regards, Chris Schnell ________________________________ The University is ranked in the QS World Rankings of the top 5% of universities in the world (QS World University Rankings, 2014) The University of Stirling is a charity registered in Scotland, number SC 011159.

9 years, 1 month

fertilisation of ponds Asian perspective

by William Leschen

On 26 October 2015 at 09:41, Peter Edwards <pedwards1943(a)gmail.com<mailto:pedwards1943@gmail.com>> wrote: Dear Will, I was pleased to read the advice from Fergus, a farmer, as I was a tad concerned that my message to learn from Asian farmers had been too general and perhaps overlooked. To ram home the message that Fergus and I are sending, at the risk of boring you, let me outline my own personal journey to grasp the fundamentals of pond fertilization. As a westerner with prior experience in botanical science as both student and lecturer in both England and America, and without any formal training in fisheries, where did I pick up my knowledge of aquaculture? Answer: from FARMERS. Although I initially worked with engineers to experiment with fish to harvest phytoplankton from a sewage-fed waste stabilization pond system at AIT , my colleagues and I then began to research livestock manure as a pond fertilizer and from there the journey into integrated farming began. Pond fertilization with fixed rates in experiments on the AIT campus and in farmers' ponds in neighbouring villages almost drove me crazy because of its variability and unpredictability. In the dim and distant past the 35 km journey to AIT from Bangkok was through rice fields but there were innumerable borrow pits or ditches alongside the road filled with an infinite variety of colours of water depending on the amount of local pollution which I used to gaze at and try to figure out what was happening. I was familiar with phytoplankton as I used to teach a graduate course at Rutgers in Algal Ecology and Physiology with emphasis on use of algae but I was totally clueless about Asian aquaculture. So we did something rather revolutionary almost 40 years ago: we carried out a survey of farmer practice in the province in which AIT is situated. Thus I became aware that Thai farmers knew how to fertilize fish ponds although they had no understanding whatsoever of the underlying science which we subsequently researched in depth for many years at AIT, with the most important findings summarized in my previous message. Field visits to several other Asian countries (e.g. China, India, Indonesia, Vietnam) revealed that farmers in both sewage-fed and livestock-manured ponds had learned the ART independently of each other. In fact, many sewage-fed systems in all the above countries depended for water only on raw wastewater as freshwater was not available. Empty fish ponds were filled up with black and anaerobic raw sewage in a process called primary fertilization. With adequate light and temperature the ponds gradually turned green with phytoplankton and the dissolved oxygen levels became suitable for fish after about 3 weeks as the bacterial decomposition of organic matter was speeded up by the oxygen released by photosynthesis. After stocking fish the nutrient levels were maintained for sufficient phytoplankton growth to feed the fish without night-time mortality through low dissolved oxygen by periodic addition of raw sewage in a process called secondary fertilization. So the most important take home message from the above rant is to learn from Asian farmer experience. It's useful to have a scientific understanding of pond fertilization but as Asian farmer experience shows, it's not necessary to use scientific paraphernalia such as oxygen meters and Secchi disks to manage fertilized fish ponds. When people express surprise that I've been in Asia for so many years, I often reply in jest: 'don't let my face fool you'. BUT I am still learning from the farmers and write up the experiences in a column I've been writing for more than a decade in each quarterly issue of NACA's magazine 'Aquaculture Asia' which is available for a free download on their website: www.enaca.org<http://www.enaca.org> (Publications, Aquaculture Asia, all issues back to 2002, so about 50 from yours truly). I don't apologise for this rather shameless personal promotion because if I don't continue to be invited to travel the world to gain more experience in aquaculture, my column will fade into oblivion. Cheers, Peter En francais au dessus Cher Will, Je suis heureux de lire l'avis de Fergus, un agriculteur, comme je l'étais un peu inquiète que mon message à apprendre des paysans asiatiques avait été trop général et peut-être négligé. Pour enfoncer le message que Fergus et je envoient, au risque de vous ennuyer, permettez-moi de présenter mon propre cheminement personnel à saisir les fondements de la fertilisation de l'étang. Comme un occidental avec une expérience préalable dans la science botanique que l'élève et maître de conférences en Angleterre et en Amérique, et sans aucune formation formelle dans les pêcheries, où ai-je ramasse ma connaissance de l'aquaculture? Réponse: des agriculteurs. Bien que je initialement travaillé avec les ingénieurs d'expérimenter avec des poissons à la récolte phytoplancton à partir d'un système d'étangs de stabilisation des déchets des eaux usées de la Fed à l'AIT, mes collègues et moi commencèrent alors à la recherche d'effluents d'élevage comme engrais de l'étang et à partir de là le voyage dans l'agriculture intégrée a commencé. La fertilisation des étangs avec des taux fixes dans les expériences sur le campus de l'AIT et dans des étangs d'agriculteurs dans les villages voisins m'a presque rendu fou parce que de sa variabilité et l'imprévisibilité. Dans la vague et lointain passé, les 35 km de parcours à l'ACI de Bangkok a été à travers les rizières, mais il y avait des fosses ou des fossés d'emprunt innombrables long de la route remplie d'une variété infinie de couleurs de l'eau en fonction de la quantité de pollution locale dont je me servais pour contempler à et essayer de comprendre ce qui se passait. Je connaissais le phytoplancton comme je l'habitude d'enseigner un cours de troisième cycle à l'université Rutgers dans Algal Ecologie et Physiologie mettant l'accent sur l'utilisation d'algues mais je suis totalement ignorant de l'aquaculture asiatique. Donc nous avons fait quelque chose d'assez révolutionnaire il ya près de 40 ans: nous avons réalisé une enquête sur les pratiques des agriculteurs dans la province où est situé l'ACI. Ainsi je suis devenu conscient que les agriculteurs thaïlandaises savaient comment fertiliser les étangs de poissons bien qu'ils aient aucune compréhension de la science sous-jacente que nous la suite des recherches en profondeur depuis de nombreuses années à l'AIT, avec les conclusions les plus importantes sont résumées dans mon message précédent. Des visites de terrain à plusieurs autres pays asiatiques (Chine, Inde, Indonésie, Vietnam) ont révélé que les agriculteurs des eaux usées-nourris et les étangs d'élevage-fumé avaient appris l'art indépendamment les uns des autres. En fait, de nombreux systèmes d'égouts nourris dans tous les pays ci-dessus dépendent de l'eau que sur les eaux usées brutes que l'eau douce était pas disponible. Les étangs de poissons vides ont été remplis avec du noir et anaérobie des eaux usées brutes dans un processus appelé fertilisation primaire. Avec la lumière et la température adéquate, les étangs progressivement verdit de phytoplancton et les niveaux d'oxygène dissous sont devenus adéquate pour les poissons au bout d'environ trois semaines que la décomposition bactérienne de la matière organique a été accélérée par l'oxygène libéré par la photosynthèse. Après l'empoissonnement les niveaux de nutriments ont été maintenus pendant la croissance du phytoplancton suffisante pour nourrir les poissons sans mortalité nuit-temps grâce à faible teneur en oxygène dissous par addition périodique des eaux d'égout brutes dans un processus appelé fertilisation secondaire. Donc, le plus important message à retenir de la diatribe ci-dessus est d'apprendre de l'expérience des agriculteurs d'Asie. Il est utile d'avoir une compréhension scientifique de fertilisation de l'étang, mais que l'expérience des agriculteurs d'Asie montre, il est pas nécessaire d'utiliser l'attirail scientifique comme les compteurs d'oxygène et les disques Secchi pour gérer les étangs de poissons fécondés. Quand les gens surprise expresse que je suis allé en Asie depuis tant d'années, je réponds souvent en plaisantant: «ne laissez pas vous tromper mon visage». Mais je suis encore à apprendre auprès des agriculteurs et de rédiger les expériences dans une colonne, je écris depuis plus d'une décennie dans chaque numéro trimestriel de la revue du CCNTA 'aquaculture en Asie », qui est disponible pour téléchargement gratuit sur leur site web: www. enaca.org (Publications, l'aquaculture en Asie, tous les problèmes remontent à 2002, donc environ 50 à partir de votre serviteur). Je ne me excuse pas pour cette promotion personnelle plutôt éhontée parce que si je ne continue pas à être invité à parcourir le monde pour acquérir plus d'expérience dans l'aquaculture, ma colonne va disparaître dans l'oubli. À votre santé, Peter 2015-10-26 4:19 GMT+07:00 William Leschen via Sarnissa-african-aquaculture <sarnissa-african-aquaculture(a)lists.stir.ac.uk<mailto:sarnissa-african-aquaculture@lists.stir.ac.uk>>: Thanks Fergus From: Fergus Flynn [mailto:fergusoaflynn@gmail.com<mailto:fergusoaflynn@gmail.com>] Sent: 25 October 2015 07:00 To: William Leschen Subject: fertilisation of ponds Hello William, It's encouraging that the subject of fertilisation rates for ponds has catalysed so much interest and discussion. Having been in commercial Tilapia production using earth ponds and integrating pigs/fish for more than 30 years I would like to reiterate what Peter Edward said. In a nutshell, whilst there are guidelines on manure loading it is far more important to use observation as the chief management tool .It is crucial to remember that each project is unique and each pond will respond differently-altitude,seasons, soil chemistry etc etc can have a profound effect on performance. It is also critical to appreciate the dynamics of such a system whereby the micro life within those individual ponds is varying by the hour,by the day by the week by the month. The best farmers are those who visually are able to interpret what is going on and respond accordingly. That's why farmers in the Far East for example who have many generations of experience on the same body of water achieve such extraordinary production results. The trick for Africa is to capture that knowledge but then translate it effectively to suit the specific location wherever it might be found on this Continent. Hope this is helpful. Kind regards Fergus Zambia Bonjour William, Il est encourageant que le sujet des taux de fertilisation pour les étangs a catalysé autant d'intérêt et de discussion. Ayant été dans la production commerciale du tilapia en utilisant des étangs en terre et en intégrant porcs / poissons pendant plus de 30 ans, je tiens à réitérer ce qu'a dit Peter Edward. En un mot, alors qu'il existe des lignes directrices sur le fumier de chargement, il est beaucoup plus important d'utiliser l'observation que l'outil de gestion chef .Il est crucial de se rappeler que chaque projet est unique et chaque étang réagira différemment altitude, les saisons, la chimie du sol, etc etc peut avoir un effet profond sur la performance. Il est également essentiel d'apprécier la dynamique d'un tel système dans lequel la vie au sein de ces micro étangs individuels varie d'heure en heure, de jour en jour par semaine par mois. Les meilleurs agriculteurs sont ceux qui sont capables d'interpréter visuellement ce qui se passe et réagir en conséquence. Voilà pourquoi les agriculteurs dans l'Extrême-Orient par exemple qui ont plusieurs générations d'expérience sur le même plan d'eau atteindre de tels résultats de production extraordinaires. L'astuce pour l'Afrique est de capturer cette connaissance mais ensuite traduire efficacement en fonction de l'endroit précis où il pourrait être trouvé sur ce continent. Espérons que cela est utile. Cordialement Fergus

9 years, 1 month

Recherche de société spécialisée dans la production de Cobia

by tning sene

Bonjour, Le Sénégal souhaite mettre en place une ferme de production de Cobia et recherche une société intéressée pour l'exploitation.Si vous êtes intéressés envoyez moi un message à t.sene(a)cdp.senegal-emergent.com tout en nous présentant votre société.Merci

9 years, 1 month

FW: Tilapia Fingerling Lesions Uganda - Tilapia Fingerling lésions Ouganda

by William Leschen

From: Karen L. Veverica [mailto:veverkl@gmail.com] Sent: 27 October 2015 14:33 To: William Leschen Subject: Re: Tilapia Fingerling Lesions Uganda - Tilapia Fingerling lésions Ouganda these look like encysted trematodes. They could also be in the gills. Please poke the cysts and see if a small worm comes out. You should also look at the gills and check the kidney for similar cysts. If it is trematodes, I will let you know more about my experience with these; mostly in Rwanda which is not too far from you. We had similar problems in Kenya but were able to manage around it. Karen L. Veverica Director, E.W. Shell Fisheries Research Center School of Fisheries, Aquaculture and Aquatic Sciences Auburn University, AL USA office: 1-334-844-4667 cell: +1 334-332-1560 En francais au dessous De: Karen L. Veverica [mailto: veverkl(a)gmail.com] Envoyé le 27 Octobre ici à 2015 14h33 Pour: William Leschen Sujet: Re: Tilapia Fingerling lésions Ouganda - Ouganda de Tilapia Fingerling ceux-ci ressemblent trématodes enkystées. Ils peuvent également se présenter sous les branchies. S'il vous plaît fouiller les kystes et de voir si un petit ver sort. Vous devriez aussi regarder les branchies et vérifier le rein pour les kystes semblables. Si elle est trématodes, je vous le ferai savoir plus sur mon expérience avec ces; la plupart du temps au Rwanda qui est pas trop loin de vous. Nous avons eu des problèmes similaires au Kenya mais nous avons pu gérer autour d'elle. Karen L. Veverica From: Lulijwa Ronnie Ronald [mailto:rlulijwa@yahoo.com<mailto:rlulijwa@yahoo.com>] Sent: 24 October 2015 17:29 To: sarnissa-african-aquaculture Mailing List Subject: Re: Tilapia Fingerling Lesions Dear Members, Could anyone have experienced these lesions in Tilapia fingerlings If any, what could be the possible cause (fungal or bacterial?) Nice evening See below for more details LULIJWA Ronald Aquaculture Scientist National Agricultural Research Organisation (NARO) Rwebitaba Zonal Agricultural Research and Development Institute. P. O. Box, 96, Fort Portal, Uganda. ________________________________ Dear Will, These fingerlings are coming from earthen ponds, that gets water from an underground spring connected to a farm reservior The area of operation is at high altitude and average temperatures are around 26°C, water quality is acceptable but with high levels of suspended solids and green water. These fish receive a supplementary diet made of formulated floating feed, and there has been no cases of mortality but that is the first case sofar reported. The stocking density is low and fingerlings size is about 5g, originating from the same farm. Thank you Lulijwa Ronald Msc Aquaculture Bsc Fisheries and Aquaculture Chers membres, Pouvait-on connu ces lésions en alevins de tilapia Le cas échéant, ce qui pourrait être la cause possible (fongique ou bactérienne?) Bonne soirée Voir ci-dessous pour plus de détails LULIJWA Ronald Aquaculture Scientiste National Agricultural Research Organisation (NARO) Rwebitaba Zonal Agricultural Research and Development Institute. P. O. Box, 96, Fort Portal, Ouganda. ________________________________________ Cher Will, Ces alevins sont en provenance des étangs de terre, qui obtient de l'eau d'une source souterraine reliée à un reservior agricole La zone d'opération est à haute altitude et les températures moyennes sont autour de 26 ° C, qualité de l'eau est acceptable, mais avec des niveaux élevés de solides en suspension et l'eau verte. Ces poissons reçoivent une alimentation complémentaire en aliments flottants formulé, et il n'y a eu aucun cas de mortalité, mais qui est le premier cas rapporté so far. La densité de peuplement est faible et alevins taille est environ 5 g, provenant de la même exploitation. Merci On Sat, Oct 24, 2015 at 9:07 PM, William Leschen <william.leschen(a)stir.ac.uk<mailto:william.leschen@stir.ac.uk>> wrote: Dear Ronald Thank you – Ive compressed down the size of your photos – also made them lighter and hopefully clearer - please can you resend again to the forum but this time include some background information about the fingerlings themselves ie From earthpond? Tank? Raceway? Hapa? Area/volume of pond? Tank etc Water source Spring? River? Borehole? Other? Water temp? Water quality ? good ? cloudy ? high suspended solids? Fed regularly? Which feed? Mortalities? Nos per day ? Size in g of fingerlings Nos in pond ?Stocking density in pond? Tank? Etc Other species in holding unit ? Polyculture or just tilapia Origin of the tilapia fingerlings ? stocked from ? If you can give these further details it will help people on the forum to give you a better informed reply Best wishes Will From: Lulijwa Ronnie Ronald [mailto:rlulijwa@yahoo.com<mailto:rlulijwa@yahoo.com>] Sent: 24 October 2015 17:29 To: sarnissa-african-aquaculture Mailing List Subject: Re: Tilapia Fingerling Lesions Dear Members, Could any one have experienced these lesions in Tilapia fingerlings If any, what could be the possible cause (fungal or bacterial) Nice evening LULIJWA Ronald Aquaculture Scientist National Agricultural Research Organisation (NARO) Rwebitaba Zonal Agricultural Research and Development Institute. P. O. Box, 96, Fort Portal, Uganda. ________________________________ The University is ranked in the QS World Rankings of the top 5% of universities in the world (QS World University Rankings, 2014) The University of Stirling is a charity registered in Scotland, number SC 011159.

9 years, 1 month

FW: Tilapia Fingerling Lesions Uganda - Tilapia Fingerling lésions Ouganda

by William Leschen

En francais au dessous From: Christophe.D [mailto:christophe_otropic@yahoo.fr] Sent: 27 October 2015 08:05 To: sarnissa-french-aquaculture Mailing List Cc: sarnissa-african-aquaculture Mailing List Subject: Re: [Sarnissa] Tilapia Fingerling Lesions Uganda - Tilapia Fingerling lésions Ouganda Dear all, I have just seen the pics …… I don’t know if you find your problem but, looks like saturation of gaz (N) ???? Maybe the first cause and certainly some parasite because your fish are stressed. Investigate your hydraulic to see what’s happen with this water who come from the ground : altitude / deep of borehole / flow / T°C and atmosphéric condition can maybe be guilty; All the best Christophe Dupuy - Expert en Aquaculture - ∼ ∼∼ ∼∼ ∼∼∼ ∼∼∼ ∼∼∼ ∼∼∼∼∼∼∼∼ ><))))°> Mobile : + 33 (0)6 20 57 12 22 Skype : Aqualog2 @ : christophe_otropic(a)yahoo.fr<mailto:christophe_otropic@yahoo.fr> Chers tous, Je viens de voir les photos ...... Je ne sais pas si vous trouvez votre problème, mais, ressemble à saturation de gaz (N) ???? Peut-être la cause première et certainement parasite parce que vos poissons sont stressés. Enquêter sur votre hydraulique pour voir ce qui ce passe avec cette eau qui viennent de la terre: l'altitude / profondeur de forage / débit / T ° C et les conditions atmosphériques peuvent peut-être être coupable; Bonne chance Christophe Dupuy - Expert en aquaculture - Le 26 oct. 2015 à 14:15, William Leschen <william.leschen(a)stir.ac.uk<mailto:william.leschen@stir.ac.uk>> a écrit : En francais au dessous From: Lulijwa Ronnie Ronald [mailto:rlulijwa@yahoo.com<mailto:rlulijwa@yahoo.com>] Sent: 24 October 2015 17:29 To: sarnissa-african-aquaculture Mailing List Subject: Re: Tilapia Fingerling Lesions Dear Members, Could anyone have experienced these lesions in Tilapia fingerlings If any, what could be the possible cause (fungal or bacterial?) Nice evening See below for more details LULIJWA Ronald Aquaculture Scientist National Agricultural Research Organisation (NARO) Rwebitaba Zonal Agricultural Research and Development Institute. P. O. Box, 96, Fort Portal, Uganda. ________________________________ Dear Will, These fingerlings are coming from earthen ponds, that gets water from an underground spring connected to a farm reservior The area of operation is at high altitude and average temperatures are around 26°C, water quality is acceptable but with high levels of suspended solids and green water. These fish receive a supplementary diet made of formulated floating feed, and there has been no cases of mortality but that is the first case sofar reported. The stocking density is low and fingerlings size is about 5g, originating from the same farm. Thank you Lulijwa Ronald Msc Aquaculture Bsc Fisheries and Aquaculture Chers membres, Pouvait-on connu ces lésions en alevins de tilapia Le cas échéant, ce qui pourrait être la cause possible (fongique ou bactérienne?) Bonne soirée Voir ci-dessous pour plus de détails LULIJWA Ronald Aquaculture Scientiste National Agricultural Research Organisation (NARO) Rwebitaba Zonal Agricultural Research and Development Institute. P. O. Box, 96, Fort Portal, Ouganda. ________________________________________ Cher Will, Ces alevins sont en provenance des étangs de terre, qui obtient de l'eau d'une source souterraine reliée à un reservior agricole La zone d'opération est à haute altitude et les températures moyennes sont autour de 26 ° C, qualité de l'eau est acceptable, mais avec des niveaux élevés de solides en suspension et l'eau verte. Ces poissons reçoivent une alimentation complémentaire en aliments flottants formulé, et il n'y a eu aucun cas de mortalité, mais qui est le premier cas rapporté so far. La densité de peuplement est faible et alevins taille est environ 5 g, provenant de la même exploitation. Merci On Sat, Oct 24, 2015 at 9:07 PM, William Leschen <william.leschen(a)stir.ac.uk<mailto:william.leschen@stir.ac.uk>> wrote: Dear Ronald Thank you – Ive compressed down the size of your photos – also made them lighter and hopefully clearer - please can you resend again to the forum but this time include some background information about the fingerlings themselves ie From earthpond? Tank? Raceway? Hapa? Area/volume of pond? Tank etc Water source Spring? River? Borehole? Other? Water temp? Water quality ? good ? cloudy ? high suspended solids? Fed regularly? Which feed? Mortalities? Nos per day ? Size in g of fingerlings Nos in pond ?Stocking density in pond? Tank? Etc Other species in holding unit ? Polyculture or just tilapia Origin of the tilapia fingerlings ? stocked from ? If you can give these further details it will help people on the forum to give you a better informed reply Best wishes Will From: Lulijwa Ronnie Ronald [mailto:rlulijwa@yahoo.com<mailto:rlulijwa@yahoo.com>] Sent: 24 October 2015 17:29 To: sarnissa-african-aquaculture Mailing List Subject: Re: Tilapia Fingerling Lesions Dear Members, Could any one have experienced these lesions in Tilapia fingerlings If any, what could be the possible cause (fungal or bacterial) Nice evening LULIJWA Ronald Aquaculture Scientist National Agricultural Research Organisation (NARO) Rwebitaba Zonal Agricultural Research and Development Institute. P. O. Box, 96, Fort Portal, Uganda. ________________________________ The University is ranked in the QS World Rankings of the top 5% of universities in the world (QS World University Rankings, 2014) The University of Stirling is a charity registered in Scotland, number SC 011159. <DSC04487.JPG><DSC04486.JPG>_______________________________________________ Sarnissa-french-aquaculture mailing list Sarnissa-french-aquaculture(a)lists.stir.ac.uk<mailto:Sarnissa-french-aquaculture@lists.stir.ac.uk> http://lists.stir.ac.uk/cgi-bin/mailman/listinfo/sarnissa-french-aquaculture

9 years, 1 month

Tilapia Fingerling Lesions Uganda - Tilapia Fingerling lésions Ouganda

by William Leschen

En francais au dessous From: Lulijwa Ronnie Ronald [mailto:rlulijwa@yahoo.com<mailto:rlulijwa@yahoo.com>] Sent: 24 October 2015 17:29 To: sarnissa-african-aquaculture Mailing List Subject: Re: Tilapia Fingerling Lesions Dear Members, Could anyone have experienced these lesions in Tilapia fingerlings If any, what could be the possible cause (fungal or bacterial?) Nice evening See below for more details LULIJWA Ronald Aquaculture Scientist National Agricultural Research Organisation (NARO) Rwebitaba Zonal Agricultural Research and Development Institute. P. O. Box, 96, Fort Portal, Uganda. ________________________________ Dear Will, These fingerlings are coming from earthen ponds, that gets water from an underground spring connected to a farm reservior The area of operation is at high altitude and average temperatures are around 26°C, water quality is acceptable but with high levels of suspended solids and green water. These fish receive a supplementary diet made of formulated floating feed, and there has been no cases of mortality but that is the first case sofar reported. The stocking density is low and fingerlings size is about 5g, originating from the same farm. Thank you Lulijwa Ronald Msc Aquaculture Bsc Fisheries and Aquaculture Chers membres, Pouvait-on connu ces lésions en alevins de tilapia Le cas échéant, ce qui pourrait être la cause possible (fongique ou bactérienne?) Bonne soirée Voir ci-dessous pour plus de détails LULIJWA Ronald Aquaculture Scientiste National Agricultural Research Organisation (NARO) Rwebitaba Zonal Agricultural Research and Development Institute. P. O. Box, 96, Fort Portal, Ouganda. ________________________________________ Cher Will, Ces alevins sont en provenance des étangs de terre, qui obtient de l'eau d'une source souterraine reliée à un reservior agricole La zone d'opération est à haute altitude et les températures moyennes sont autour de 26 ° C, qualité de l'eau est acceptable, mais avec des niveaux élevés de solides en suspension et l'eau verte. Ces poissons reçoivent une alimentation complémentaire en aliments flottants formulé, et il n'y a eu aucun cas de mortalité, mais qui est le premier cas rapporté so far. La densité de peuplement est faible et alevins taille est environ 5 g, provenant de la même exploitation. Merci On Sat, Oct 24, 2015 at 9:07 PM, William Leschen <william.leschen(a)stir.ac.uk<mailto:william.leschen@stir.ac.uk>> wrote: Dear Ronald Thank you – Ive compressed down the size of your photos – also made them lighter and hopefully clearer - please can you resend again to the forum but this time include some background information about the fingerlings themselves ie From earthpond? Tank? Raceway? Hapa? Area/volume of pond? Tank etc Water source Spring? River? Borehole? Other? Water temp? Water quality ? good ? cloudy ? high suspended solids? Fed regularly? Which feed? Mortalities? Nos per day ? Size in g of fingerlings Nos in pond ?Stocking density in pond? Tank? Etc Other species in holding unit ? Polyculture or just tilapia Origin of the tilapia fingerlings ? stocked from ? If you can give these further details it will help people on the forum to give you a better informed reply Best wishes Will From: Lulijwa Ronnie Ronald [mailto:rlulijwa@yahoo.com<mailto:rlulijwa@yahoo.com>] Sent: 24 October 2015 17:29 To: sarnissa-african-aquaculture Mailing List Subject: Re: Tilapia Fingerling Lesions Dear Members, Could any one have experienced these lesions in Tilapia fingerlings If any, what could be the possible cause (fungal or bacterial) Nice evening LULIJWA Ronald Aquaculture Scientist National Agricultural Research Organisation (NARO) Rwebitaba Zonal Agricultural Research and Development Institute. P. O. Box, 96, Fort Portal, Uganda. ________________________________ The University is ranked in the QS World Rankings of the top 5% of universities in the world (QS World University Rankings, 2014) The University of Stirling is a charity registered in Scotland, number SC 011159.

9 years, 1 month

Probiotics ? Pond fertilisation ……..

by William Leschen

Probiotics ? Pond fertilisation …….. Read through thread - En francais au dessous [cid:image003.jpg@01D10FDC.64D5CCD0] Dear Anetekhai I didn’t recommend probiotics …. ! Murali did - one of our fish farming members - I am posting your reply up on the forum to see if others have any thoughts or ideas about using and paying for probiotics to fertilise their ponds for tilapia catfish – their positive and or negative effects? Personally I don’t think its relevant here as they are normally used in Asia for other purposes particularly related to health on commercial shrimp farms - Note in Nigeria as you are probably aware they (and their like) are increasingly being added as feed supplements for the Clarias hatchery and juveniles without in a lot of cases in my opinion the fish farmers actually knowing what they are buying and using – also in Nigeria “Tonics” for pond water quality now been openly sold off the shelf (at high prices) in bottles and packets by pharmaceutical companies which again the fish farmers have little idea what the active ingredients are and how they should work – or I should say IF they work . With respect For pond fertilisation I would read carefully the words of the people who have been doing it years in Asia and some in Africa - and realise that this is something that cannot just come out of a text book or be remedied by buying a packet or bottle from a pharmacist – is site specific and has to come from careful observation and years of experience…… Best wishes Will From: Anetekhaimartins [mailto:anetekhaimartins@gmail.com] Sent: 26 October 2015 07:30 To: William Leschen Subject: RE: FW: Semi-intensive ponds Optomimum fetilsation and maintenance Mozambique Good day William, I just read one of your responses in which you recommended probiotic. I have also observed some farmers bringing into Nigeria some probiotics for use. My fear is that there may be negative impact on the long run. Are you aware of any such report? Can you educate me on any negetive impact. Thank you. Anetekhai martins Cher Anetekhai Je ne recommande pas les probiotiques .... ! Murali a fait - l'un de nos membres de pisciculture - je poster votre réponse sur le forum pour voir si d'autres ont des pensées ou des idées sur l'utilisation et le paiement des probiotiques pour fertiliser leurs étangs du tilapia poisson-chat? Personnellement, je ne pense pas que son compte ici, car ils sont normalement utilisés en Asie à d'autres fins liées notamment à la santé sur les élevages de crevettes commerciaux - Note au Nigeria que vous êtes probablement au courant qu'ils (et leurs semblables) sont de plus en plus ajoutés comme compléments alimentaires pour l'écloserie de Clarias et mineurs sans en beaucoup de cas, à mon avis, les pisciculteurs sachant réellement ce qu'ils achètent et utilisent - aussi au Nigeria "toniques" pour la qualité de l'eau de l'étang désormais ouvertement vendus (à des prix élevés) dans des bouteilles et des paquets par les compagnies pharmaceutiques qui encore une fois les pisciculteurs ont peu idée de ce que les ingrédients actifs sont et comment ils doivent travailler - ou devrais-je dire si elles travail . Avec respect pour la fertilisation des étangs Je voudrais lire attentivement les paroles des gens qui ont fait ça années en Asie et dans certains pays africains - et de réaliser que ceci est quelque chose qui ne peut pas juste de sortir d'un livre de texte ou être remédié par un achat d'un paquet - est spécifique au site et doit venir de l'observation et des années d'expérience attention ...... Amicalement Will De: Anetekhaimartins [mailto: anetekhaimartins(a)gmail.com] Envoyé 26 Octobre ici à 2015 7:30 Pour: William Leschen Sujet: Re: FW: étangs semi-intensifs fetilsation Optomimum et l'entretien du Mozambique Bonjour William, Je viens de lire un de vos réponses dans lequel vous recommandé probiotique. Je ai également observé certains agriculteurs mettant en Nigeria certains probiotiques pour l'utilisation. Ma crainte est qu'il peut y avoir des répercussions négatives sur le long terme. Etes-vous conscient d'un tel rapport? Pouvez-vous me renseigner sur tout impact negetive. Merci. Martins Anetekhai -------- Original message -------- From: William Leschen via Sarnissa-african-aquaculture <sarnissa-african-aquaculture(a)lists.stir.ac.uk<mailto:sarnissa-african-aquaculture@lists.stir.ac.uk>> Date: 24/10/2015 1:55 PM (GMT+01:00) To: sarnissa-african-aquaculture Mailing List <sarnissa-african-aquaculture(a)lists.stir.ac.uk<mailto:sarnissa-african-aquaculture@lists.stir.ac.uk>> Subject: FW: Semi-intensive ponds Optomimum fetilsation and maintenance Mozambique From: chnmurali(a)gmail.com<mailto:chnmurali@gmail.com> [mailto:chnmurali@gmail.com] Sent: 24 October 2015 10:12 To: William Leschen Subject: Re: Semi-intensive ponds Optomimum fetilsation and maintenance Mozambique Dear William Looking at the parameters sent by Chris it clearly says that pond is over blooming since the oxygen levels are over saturated. He mentioned total alkalinity as 180 but did not mention about carbonate and bicarbonate alkalinity or pH, I assume that pH will be definitely high in the evening times with high carbonates and also more CO2 in the early hours. This condition will subject the fish to extreme stress and sometimes mass mortality in early hours. Dilluting pond with fresh water also not a solution, the more you flush the more it blooms if the pond has accumulated organic load and high nitrogen levels. My suggestion is to drain surface water in the mid afternoon when plankton will be floating on surface at higher density and top up water in the night time. Add Sodium carbonate in the early hours to reduce CO2 and not to rise pH, never go to Calcium based liming products till he get stabilized pH. I assume that pH fluctuation at this stage might be more than 1, it's has to come down to 0.5 then only we can say buffering is good. Either organic or inorganic fertiliser he has to make a slurry, and broadcast that in water to avoid organic load entering pond when using organic fertiliser or inorganic fertiliser helping growth of macrophytes. He should not stop feeding but reduce it to half until bloom is stabilised. Start using Probiotics which can take care of water quality. With Regards Murali Sent from my iPhone On 24 Oct 2015, at 8:03 AM, William Leschen via Sarnissa-african-aquaculture <sarnissa-african-aquaculture(a)lists.stir.ac.uk<mailto:sarnissa-african-aquaculture@lists.stir.ac.uk>> wrote: Thanks Warren - Manual contains nice review of pond fertilisation Hi Chris, Farmers do this by looking at the water colour and fertilising in response to this. There will tend to be a need to increase fertilisation over time as the fish grow. A dried pond just filled with go green easily due to good light penetration. Turbidity reduces light penetration which phytoplankton depend on. Earthen ponds get more turbid with time. Soil obviously has a big effect. Cloudy weather also. Don't be tempted to keep putting in more fertiliser if the pond doesn't go green, particularly if the weather is very cloudy all day. As soon as you get a sunny day it will change to pea soup. The recommended amount found by research at AIT is 4 kg of nitrogen and 1-2 kg of phosphorous per ha per day. Of course you need to know how much N and P are in any organic ferilisers. Inorganic fertiliser is easier to calculate. %N is quoted on the bag, but P is quoted as P2O5 and to calculate how much P in a kg you need to allow of the oxygen. 1 mole of P is 30.974g and a mole of oxygen is 15.999. So a mole of P2O5 would weigh 109.918. 61.948g of this is P which is equivalent to 56.36% In 1 kg of16-20-0 fertiliser (N-P-K) you have 160g of N and 200 x 56.36% = 112.7g P. See this link to a pond rearing manual I put on the website = http://tilapiathai.com/asset/NILE%20TILAPIA%20CULTURE%20IN%20EARTHEN%20POND… If you are using inorganics and are adding N and P only, you might want to try adding K. For example, we used to use 16-20-0 which we apply at 187 kg/ha/week. We now use 15-15-15 at the same rate, as we find it gets the pond green better I assume as K is limiting sometimes. If the pond doesn't go green we can try adding dolomite which contains magnesium. If you are adding some organics, then you won't have deficiency of elements required in small amounts. Secchi disk measurements will relate not just to phytoplantkton levels, but all suspended solids. Chlorophyll levels can be measured, but it really isn't difficult to do it by eye. Remember that any feed going in the pond is also adding N and P. Best Warren On Thu, Oct 22, 2015 at 8:12 PM, William Leschen <william.leschen(a)stir.ac.uk<mailto:william.leschen@stir.ac.uk>> wrote: Dear Chris Thanks I will post this up on the sarnissa forum but am also copying to - rather than limnologists – much better in my opinion those who have applied and practiced hands on over many years - Peter (Edwards – you’ve already corresponded with him) and also Warren Turner in Thailand as Warren at Namsai has worked out protocols over the years for optimum fertilisation of his ponds and also maintenance/balance of blooms over longer prod time periods - noting also though that as you know the local pond substrate , water quality at inflow go to make up very specific water chemistry for particular sites – each one different – also their particular buffering capacity towards more stable algal bloom production over time - I think I realised a while ago on visits to long well established greenwater pond systems China exactly how much of a skill and an art this is – - and something that is very much experience based not just getting figures and dose rates for organic and inorganic from text books. Ive also copied to Mark Amechi in Ghana as his pond hatchery site through a nos of French origin site managers has developed greenwater pond systems for them that work over the years - Also for you might be worth looking to trial 1-2 ponds from scratch seeding of specific algal species ?If you haven’t already I would recommend looking at some of Claude Boyds now old but still very valid publications from Auburn - books but also plenty of papers Eg http://www.alibris.com/Dynamics-of-Pond-Aquaculture-Claude-E-Boyd/book/1847… http://www.amazon.com/By-Claude-Boyd-Aquaculture-Management/dp/B008WDSSL0 Best wishes Will From: Chris Schnell [mailto:cwschnell@gmail.com<mailto:cwschnell@gmail.com>] Sent: 22 October 2015 13:36 To: William Leschen Subject: Semi-intensive ponds Dear Will, If you have a limnologist in the forum, he could possibly help me resolve my questions. Or, anyone with experience of growing tilapia in mud ponds would most probably be able to clarify things. Producing tilapia in semi-intensive mud ponds using algae and supplementary feed is not all that easy as it sounds, especially when you start having problems with fertilizing the water. What is the best way to measure primary production of algae? Does oxygen levels tell the whole story, or does one also look at the green / grey colour of the water? Or are there better methods? My problem started with overdosing. It seems as if it takes a long time to dilute one’s nutrients and algae once you have a bloom with a reading of less than 15 cm on the Secchi disk. For financial reasons I did not want to remove water from my pond after over dosing, but now I keep on adding more water and the Secchi readings do not go up. I cut down dramatically in adding new fertilizer. This makes me worry that the algae in the pond could be dead or just floating solids and that the primary production, that serves as feed for the tilapia, is not sufficient. My ponds are around 1 hectare in size and the depth varies between 400mm and 900mm. Temperature is 27°C at the bottom and 29°C at the surface. Oxygen at 12h00 is 12.5 ml/l at the surface and 9.5 ml/l at a depth of 900 mm. I fertilise with dry cow manure, Urea and DAP. Total alkalinity is around 180. Best regards, Chris Schnell ________________________________ The University is ranked in the QS World Rankings of the top 5% of universities in the world (QS World University Rankings, 2014) The University of Stirling is a charity registered in Scotland, number SC 011159.

9 years, 1 month

fertilisation of ponds

by William Leschen

Thanks Fergus From: Fergus Flynn [mailto:fergusoaflynn@gmail.com] Sent: 25 October 2015 07:00 To: William Leschen Subject: fertilisation of ponds Hello William, It's encouraging that the subject of fertilisation rates for ponds has catalysed so much interest and discussion. Having been in commercial Tilapia production using earth ponds and integrating pigs/fish for more than 30 years I would like to reiterate what Peter Edward said. In a nutshell, whilst there are guidelines on manure loading it is far more important to use observation as the chief management tool .It is crucial to remember that each project is unique and each pond will respond differently-altitude,seasons, soil chemistry etc etc can have a profound effect on performance. It is also critical to appreciate the dynamics of such a system whereby the micro life within those individual ponds is varying by the hour,by the day by the week by the month. The best farmers are those who visually are able to interpret what is going on and respond accordingly. That's why farmers in the Far East for example who have many generations of experience on the same body of water achieve such extraordinary production results. The trick for Africa is to capture that knowledge but then translate it effectively to suit the specific location wherever it might be found on this Continent. Hope this is helpful. Kind regards Fergus Zambia Bonjour William, Il est encourageant que le sujet des taux de fertilisation pour les étangs a catalysé autant d'intérêt et de discussion. Ayant été dans la production commerciale du tilapia en utilisant des étangs en terre et en intégrant porcs / poissons pendant plus de 30 ans, je tiens à réitérer ce qu'a dit Peter Edward. En un mot, alors qu'il existe des lignes directrices sur le fumier de chargement, il est beaucoup plus important d'utiliser l'observation que l'outil de gestion chef .Il est crucial de se rappeler que chaque projet est unique et chaque étang réagira différemment altitude, les saisons, la chimie du sol, etc etc peut avoir un effet profond sur la performance. Il est également essentiel d'apprécier la dynamique d'un tel système dans lequel la vie au sein de ces micro étangs individuels varie d'heure en heure, de jour en jour par semaine par mois. Les meilleurs agriculteurs sont ceux qui sont capables d'interpréter visuellement ce qui se passe et réagir en conséquence. Voilà pourquoi les agriculteurs dans l'Extrême-Orient par exemple qui ont plusieurs générations d'expérience sur le même plan d'eau atteindre de tels résultats de production extraordinaires. L'astuce pour l'Afrique est de capturer cette connaissance mais ensuite traduire efficacement en fonction de l'endroit précis où il pourrait être trouvé sur ce continent. Espérons que cela est utile. Cordialement Fergus

9 years, 1 month

Semi-intensive ponds Pond fertilisation Query from Mozambique

by William Leschen

Un document sur le fumier de vache et fourrage exogène dans tilapia des étangs de terre qui peuvent aider Attaché. Meilleures salutations Dr Victor Pouomogne Boite Postale 139 Foumban, Cameroun From: Pouomogne Victor [mailto:pouomognev@yahoo.fr] Sent: 23 October 2015 13:33 To: sarnissa-french-aquaculture Mailing List Subject: Re: [Sarnissa] Semi-intensive ponds Pond fertilisation Query from Mozambique Attached a paper on cow manure and exogen feed in tilapia earthen ponds that may help. Kindest regards Dr Victor Pouomogne Boite Postale 139 Foumban, Cameroun CellPhone +237 677 590 026 Le Jeudi 22 octobre 2015 17h06, "jeremiah.minich(a)gmail.com<mailto:jeremiah.minich@gmail.com>" <jeremiah.minich(a)gmail.com<mailto:jeremiah.minich@gmail.com>> a écrit : Dear Chris, Why have you chosen cow manure and do you have access to chicken? How often are you fertilizing and with how much manure? Generally it's recommended to use fresh chicken manure at 500kg per month per HA pond. Cow manure has less nutrients and thus you need more manure to get blooms. With more manure, you have more "dead" stuff on the bottom. It looks as if your oxygen is fine- how certain are you of your meter... How many fish, what are your conditions ? Sex and size? Sent from my iPhone On Oct 22, 2015, at 6:42 AM, William Leschen via Sarnissa-african-aquaculture <sarnissa-african-aquaculture(a)lists.stir.ac.uk<mailto:sarnissa-african-aquaculture@lists.stir.ac.uk>> wrote: En francais au dessous Dear Will, If you have a limnologist in the forum, he could possibly help me resolve my questions. Or, anyone with experience of growing tilapia in mud ponds would most probably be able to clarify things. Producing tilapia in semi-intensive mud ponds using algae and supplementary feed is not all that easy as it sounds, especially when you start having problems with fertilizing the water. What is the best way to measure primary production of algae? Does oxygen levels tell the whole story, or does one also look at the green / grey colour of the water? Or are there better methods? My problem started with overdosing. It seems as if it takes a long time to dilute one’s nutrients and algae once you have a bloom with a reading of less than 15 cm on the Secchi disk. For financial reasons I did not want to remove water from my pond after over dosing, but now I keep on adding more water and the Secchi readings do not go up. I cut down dramatically in adding new fertilizer. This makes me worry that the algae in the pond could be dead or just floating solids and that the primary production, that serves as feed for the tilapia, is not sufficient. My ponds are around 1 hectare in size and the depth varies between 400mm and 900mm. Temperature is 27°C at the bottom and 29°C at the surface. Oxygen at 12h00 is 12.5 ml/l at the surface and 9.5 ml/l at a depth of 900 mm. I fertilise with dry cow manure, Urea and DAP. Total alkalinity is around 180. Best regards, Chris Schnell Xibaha Tilapia Mozambique Cher Will, Si vous avez un limnologue dans le forum, il pourrait peut-être me aider à résoudre mes questions. Ou, quelqu'un avec une expérience croissante du tilapia dans les étangs de boue serait probablement en mesure de clarifier les choses. Produire tilapia dans les étangs de boue semi-intensifs à base d'algues et d'alimentation complémentaire est pas si facile que cela puisse paraître, surtout quand vous commencez à avoir des problèmes avec la fertilisation de l'eau. Quelle est la meilleure façon de mesurer la production primaire des algues? Les niveaux d'oxygène ne disent pas toute l'histoire, ou t-on aussi regarder la couleur vert / gris de l'eau? Ou y at-il de meilleures méthodes? Mon problème a commencé avec un surdosage. Il semble que si elle prend beaucoup de temps pour diluer ses éléments nutritifs et les algues une fois que vous avez une fleur avec une lecture de moins de 15 cm sur le disque de Secchi. Pour des raisons financières, je ne voulais pas enlever l'eau de mon bassin, après plus de dosage, mais maintenant je continue à ajouter plus d'eau et les lectures à ne pas monter. Je réduis considérablement en ajoutant de nouveaux engrais. Cela me fait peur que les algues dans l'étang pourrait être solides ou tout simplement morts flottants et que la production primaire, qui sert de fourrage pour le tilapia, ne suffit pas. Mes étangs sont environ 1 hectare en taille et la profondeur varie entre 400mm et 900mm. La température est de 27 ° C à la base et 29 ° C en surface. Oxygène à 12h00 est de 12,5 ml / L à la surface et de 9,5 ml / l à une profondeur de 900 mm. Je fertilise avec du fumier de vache sèche, l'urée et DAP. L'alcalinité totale est d'environ 180. Cordialement, Chris Schnell Xibaha Tilapia Mozambique _______________________________________________ Sarnissa-french-aquaculture mailing list Sarnissa-french-aquaculture(a)lists.stir.ac.uk<mailto:Sarnissa-french-aquaculture@lists.stir.ac.uk> http://lists.stir.ac.uk/cgi-bin/mailman/listinfo/sarnissa-french-aquaculture

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Sarnissa-french-aquaculture October 2015