Éditeur(s) : Université de La Rochelle
Résumé : Shrimp aquaculture in New Caledonia is a developing industry, exclusively based on the species Litopenaeus stylirostris. However, it is subject to mortalities during grow out as observed all over the world. Since 1993, shrimp reared during the cold period are affected by a disease named "syndrome 93". As a consequence, the whole industry has become seasonal and produces essentially during the warm season. The climatic conditions during the periods of transition between the two main seasons could be responsible for an environmental stress and the origin reason for mortality outbreaks. Stocking density is the main risk factor. It increases the probability of the appearance and development of the epizooty in the pond. The "Summer Syndrome", a septicemic vibriosis caused by Vibrio nigripulchritudo, was identified for the first time in December 1997 in an intensive shrimp farm (DF). It has become enzootic ever since and is expressed after 50d of rearing. Since 2003, two others farms located near DF have developed the disease. As a consequence, the summer syndrome is considered to be a potential threat for all the industry. Between 1991 and 2005, the increase of feed input and nitrogen levels in feed has led to a significant increase in the growth rate over the years in the farms affected by the disease. In consequence, an early eutrophication of the water is observed, which is concomitant with the beginning of the mortality outbreaks. An early eutrophication and the virulence level of the pathogen are considered as the main risk factors of the disease. Factors may act synergistically to explain the summer syndrome. As part of a multidisciplinary approach (pathology – physiology – environment), two high-frequency surveys were carried out to analyse the pond ecosystem. Since the feed quantity increases with the biomass of shrimp, the eutrophication level of the pond ecosystem will also tend to increase with the duration of rearing. During the first part of the rearing, the abundance of each picoplankton type is exceptionally high and picophytoplankton dominated the autotrophic compartment. The nanophytoplankton dominated the second part of the rearing and was more unstable. The shift from pico to nanophytoplankton could be considered as an environmental stress and was observed in relation to the beginning of the mortalities, whatever the disease. Shift intensity could play a role by inducing directly or indirectly a stress for shrimp and/or a growth and/or virulence factors of the pathogen. Results from sediment studies show that mortality was best characterized by TAN concentration in pore water and even more when the TAN concentration was high. TAN and pH are potential stress factors for shrimp reared in ponds affected by these diseases.
L'aquaculture mondiale de crevettes est un secteur à très forte croissance. Toutefois, les problèmes liés aux maladies dans les élevages ne cessent d'augmenter depuis 1980. Au cours du développement de la filière de Nouvelle-Calédonie, deux épisodes saisonniers de mortalités associées à la présence de Vibrio pathogènes sont apparus et ont fortement perturbé les techniques et les schémas de production. Les premières mortalités hivernales, décrites sous le nom de « syndrome 93 » ont été observées en mai 1993. Elles ont affecté depuis tous les élevages de saison froide de toutes les fermes de production. Les conditions climatiques pendant les périodes de transitions entre les deux principales saisons caractérisant le climat de la Nouvelle-Calédonie, seraient responsables d'un stress environnemental à l'origine du déclenchement du syndrome 93. La densité initiale d'ensemencement, apparaît comme le principal facteur de risque, augmentant la probabilité d'apparition de la maladie et l'ampleur de ses effets. Le « syndrome d'été » a été identifié pour la première fois en 1997 dans une ferme pratiquant une production intensive. Il s'est déclaré depuis 2003 dans deux autres fermes géographiquement proches. Les mortalités apparaissent 58 jours en moyenne après l'ensemencement des post-larves dans les bassins. La recherche d'une croissance maximale des animaux a induit, avec les années, une intensification progressive du système caractérisée par une augmentation de la quantité d'aliment distribuée. L'examen des données historiques fait apparaître une eutrophisation du milieu de plus en plus précoce concomitante au déclenchement des mortalités. En l'état actuel de nos connaissances, cette évolution précoce de l'écosystème en présence de façon récurrente de la souche hautement pathogène du Vibrio incriminé et à une période où la fréquence des mues des crevettes est élevée, constitue le principal facteur de risque de la maladie. Avec l'apport croissant en aliment, la colonne d'eau évolue vers une autotrophie croissante alors que le sédiment devient de plus en plus hétérotrophe au fur et à mesure que l'élevage progresse. Au cours du processus d'eutrophisation, le compartiment autotrophe montre une succession de deux assemblages. Le picophytoplancton domine sur la première partie de l'élevage et laisse place à du nanophytoplancton en seconde partie. Cette phase de transition, concomitante à l'apparition des mortalités quel que soit le syndrome, caractérise un stress environnemental dont l'intensité pourrait favoriser ou non le déclenchement des mortalités. Les suivis de différents indicateurs dans les sédiments - pH, potentiel d'oxydoréduction et concentration en ammoniaque dans l'eau interstitielle – indiquent dans les bassins déclarant les épizooties des conditions qui ont été définies expérimentalement comme potentiellement plus stressantes pour les animaux.

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/2007/these-2643.pdf
http://archimer.ifremer.fr/doc/00000/2643/

Éditeur(s) : EDP Sciences
Résumé : During 84 days, the effects of density on juvenile sea bass (Dicentrarchus labrax) (76 +/- 16 g) were studied in an experimental tank-based flow through system. Performance, stress response and resistance to virus infection were analysed under five stabilized rearing densities: 10, 20, 40, 70 and 100 kg m(-3). Water quality parameters (CO2, total ammonia nitrogen and O-2) were measured and maintained close to the recommended values for farmed sea bass by adjusting water renewal exchange. No significant differences were observed between density treatments, neither on stress response (cortisol) nor susceptibility to nodavirus. With regards to biological performances, the daily feed intake and specific growth rate were significantly lower in fish reared at the 100 kg m(-3) density. Results on the effects of density in sea bass reared in flow through (present study) and in recirculating aquaculture systems (RAS) (Sammouth et al. 2009) were compared as a contribution to the identification of density not affecting health and welfare in farmed sea bass.
Aquatic Living Resources (0990-7440) (EDP Sciences), 2010-01 , Vol. 23 , N. 1 , P. 109-117

Droits : 2010 EDP Sciences, IFREMER, IRD
http://archimer.ifremer.fr/doc/00002/11287/7824.pdf
DOI:10.1051/alr/2009056
http://archimer.ifremer.fr/doc/00002/11287/

Éditeur(s) : Elsevier
Résumé : We examined the potential for producing the large numbers of sandfish (Holothuria scabra) needed for restocking programmes by co-culturing juveniles with the shrimp Litopenaeus stylirostris in earthen ponds. Our experiments in hapas within shrimp ponds were designed to detect any deleterious effects of sandfish on shrimp, and vice versa. These experiments showed that a high stocking density of juvenile sandfish had no significant effects on growth and survival of shrimp. However, survival and growth of sandfish reared with shrimp for 3 weeks were significantly lower than for sandfish reared alone. Increased stocking density of shrimp also had a significant negative effect on survival and/or growth of sandfish. A grow-out trial of juvenile sandfish in 0.2-ha earthen ponds stocked with 20 shrimp post-larvae m(-2), and densities of sandfish between 0.8 and 1.6 individuals m(-2), confirmed that co-culture is not viable. All sandfish reared in co-culture were dead or moribund after a month. However, sandfish stocked alone into 0.2-ha earthen ponds survived well and grew to mean weights of similar to 400 g within 12 months without addition of food. The grow-out trial demonstrated that there is potential for profitable pond farming of sandfish in monoculture. Further research is now needed to identify the optimal size of juveniles, stocking densities and pond management regimes. (C) 2007 Elsevier B.V. All rights reserved.
Aquaculture (0044-8486) (Elsevier), 2007-12 , Vol. 273 , N. 4 , P. 509-519

Droits : 2007 Elsevier B.V. All rights reserved.
http://archimer.ifremer.fr/doc/2007/publication-3590.pdf
DOI:10.1016/j.aquaculture.2007.07.015
http://archimer.ifremer.fr/doc/00000/3590/

Éditeur(s) : Blackwell science
Résumé : Peneid shrimp are commonly reared in clear-water aquaria or tanks for short-term studies of 4-6 weeks during controlled experiments, such as nutrition studies to estimate dietary nutrient requirements. Recently, in line with the genetic program at Centre Oceanologique du Pacifique (COP), experimental clear-water facilities were tested for the first time over a longer rearing period. Environmental conditions used to maintain animal growth in clear-water system using a well-balanced diet were defined. After 100 days, shrimp growth rates tended to decrease and only by adjusting the diet could shrimp complete their life cycle and reach maturation size of around 40 g. This paper presents information on stocking density, diet quality and husbandry linked to reproduction that must be considered to successfully rear animals from PL's to breeder size in clear water. By following these protocols a minimum amount of breeders can be used to meet production goals. Moreover, by isolating a small group of individuals, genetic diversity can be preserved, thereby allowing specific crosses for selective breeding purposes. Length of trials, amount of feed, composition of feed, growth performances and maturation success are reported and should encourage further studies to optimize rearing conditions in clear-water rearing.
Aquaculture Research (1355-557X) (Blackwell science), 2004-11 , Vol. 35 , N. 13 , P. 1244-1252

Droits : 2004 Blackwell Synergy
http://archimer.ifremer.fr/doc/2004/publication-619.pdf
DOI:10.1111/j.1365-2109.2004.01145.x
http://archimer.ifremer.fr/doc/00000/619/

Éditeur(s) : Edp Sciences S A
Résumé : Reared sea bass were submitted to six stressful situations: hyperoxia with or without hypercapnia, increased stocking density in an open flow or recirculating system, transfer to another tank and nodavirus injection. The potentially negative impact of these factors on the lives of sea bass was investigated by measuring 9 water parameters and 19 fish parameters including total serum protein (TSP). TSP has already been used to evaluate stress. The present study investigates data of previous and new experiments, concentrating on the potential use of TSP as a routine indicator to assess welfare in sea bass reared on fish farms. In the current experiment, oxygen and carbon dioxide were seen to affect levels of TSP, but alterations were too erratic to enable proper comparison, probably because they are normal components of the fish environment and become toxic only by dose increase. TSP decreased when stocking density increased. After transfer to another tank, TSP decreased to 14% for three weeks and then increased during the fourth week through compensative overproduction, before returning to normal levels after 2 months. The results confirmed that transfer is an important stress factor for fish, with cumulative effects for successive transfers. TSP alteration of nodavirus-injected fish depends on the type of symptoms, which can be divided into 3 groups: (i) dying fish, in which TSP increased sharply due to over-production of protein involved in non-specific defences and inflammation, then decreased dramatically before death; (ii) whirling fish, a group that included both fish that later died, in which TSP decreased, and fish that subsequently survived, in which TSP increased due to development of specific immunity; and (iii) asymptomatic fish, in which TPS was similar to control levels and which were probably insensitive to nodavirus and/or had developed defences. In this paper, different mechanisms of TSP alteration are proposed and the interest of TSP as a field parameter is discussed. TSP is a non-destructive parameter that is robust, easy to measure everywhere and cheap, representing a suitable way of monitoring the overall welfare of fish by its regular increase. It can be used only as a "warning" of poor rearing conditions, however, and further investigations would be needed to identify the specific stress or health disorder.
Aquatic Living Resources (0990-7440) (Edp Sciences S A), 2011-04 , Vol. 24 , N. 2 , P. 121-127

Droits : EDP Sciences, IFREMER, IRD 2011
http://archimer.ifremer.fr/doc/00043/15382/12740.pdf
DOI:10.1051/alr/2011130
http://archimer.ifremer.fr/doc/00043/15382/

Éditeur(s) : Elsevier
Résumé : Two populations of the Latin American shrimp Penaeus (Litopenaeus)stylirostris domesticated in Hawaii and in New Caledonia were previously shown to be genetically differentiated and proven highly inbred. In New Caledonia, where different Vibriosis affect shrimp production and antibiotic use is banned in growing ponds, the Hawaiian population was introduced to increase the allelic variability available for local shrimp farmers and start a genetic improvement program. Growth and survival rates of the two pure populations and the two-way F-1-hybrids obtained by breeding Hawaiian animals with New Caledonian animals were assessed in several simple experiments (earthen ponds, floating cages and experimental infection challenges) during two years on two successive generations. Results were very consistent: F-1-hybrids growth rates in earthen ponds were 37% (+/-7% SD) higher than for pure populations. Cage experiments demonstrated no competition between the different populations when reared together or separately in a common environment. The F-1-hybrids also showed better survival rates in all experiments. Combining the results on growth and survival rates leads to the conclusion that biomass production is much higher with F-1-hybrid populations than with pure populations using the same quantity of juveniles stocked: biomass production in ponds was increased 1.4 and 2.3 times on year I and year 2 respectively, and 1.9 times in floating cages. The advantage of growing F-1-hybrids appeared proportionally higher when environmental and sanitary conditions led to poorer survival (34% in year 2 vs. 56% in year 1). These results are a good example of performance improvement by heterosis effect and/or of performance loss due to inbreeding in the pure populations. This study demonstrates that aquaculture industries which cannot afford large selection programs may benefit from using two different inbred parental stocks to produce F-1-hybrids for each commercial growout. This is notably true when only inbred populations are available, or when introduction of genetic variability from the wild or from other genetic resources represents a zoo-sanitary risk. In our case, the expected increase in L stylirostris production could be around 85% (according to our average results) if producers keep stocking their ponds at their current densities using F-1-hybrids. However, for sustainability reasons, it is advisable to stock F-1-hybrid animals at lower densities, the gain in performance allowing producing the same amount of biomass with less input. (C) 2008 Elsevier B.V. All rights reserved.
Aquaculture (0044-8486) (Elsevier), 2008-06 , Vol. 278 , N. 1-4 , P. 43-50

Droits : 2008 Elsevier B.V. All rights reserved.
http://archimer.ifremer.fr/doc/2008/publication-4316.pdf
DOI:10.1016/j.aquaculture.2008.03.018
http://archimer.ifremer.fr/doc/00000/4316/

Éditeur(s) : Man and Coastal Areas – Towards a sustainable Aquaculture, May 2000
Résumé : Fish culture (seabass, turbot...) on the French metropolitan coast, and shrimp culture in the overseas territories (essentially New Caledonia and Tahiti) are subject to a regular development through land based farms. Three thematic of research on aquaculture ponds are carried out in CREMA-L’Houmeau, in collaboration with producers. The aim of the first one is to determine the optimal rearing conditions (stocking density, water renewal rate, input of oxygen, rate of feeding...) which allow to minimise the quantity of wastes for a similar final biomass. The second part aims to reduce the nutrient loading in the effluent, through open-air treatments: sedimentation ponds, foam fractionation, mass production of phytoplankton, and rearing of molluscs on the produced phytoplankton. The third part concerns research aiming to model the “ production - treatment - valorisation ” relationships.

Droits : 2000 Ifremer
http://archimer.ifremer.fr/doc/00016/12728/9650.pdf
http://archimer.ifremer.fr/doc/00016/12728/

Résumé : Larval mortalities occurring in molluscan hatcheries have often been associated with bacterial contamination. Although batches of oyster and clam larvae have been routinely reared in the hatchery of Argenton without antibiotics, high larval mortalities have been recorded with Pecten maxirnus under similar conditions. For this species, an addition of chloramphenicol was found necessary. However, this chemical has now been banned in Europe. Thus either substitition products or an improvement in the rearing procedures is essential. Studies carried out have shown that neither a decrease in larval density (1 larvae. ml"l) nor sea water change frequency (1 per day) had any positive effects. Furthermore, elective substances such as sugars were not suitable and the use of another antibiotic, erytromvcine. led to inconsistent results-
En ecloserie de mollusques, les mortalités larvaires sont souvent associées à des proliférations bactériennes. Pour les limiter un traitement de l'eau est incontournable et chez certaines espèces, dont la coquille St Jacques Pecten maximus, l'utilisation de chloramphenicol s'avère nécessaire. Or son usage dans les productions animales a été récemment prohibé par la communauté européenne. Afin de pallier à cette interdiction, l'amélioration des procédures zootechniques ainsi que l'utilisation de produits de substitution ont été effectuées. Quel que soit le procédé envisagé, abaissement de la densité en élevage, augmentation de la fréquence du renouvellement de l'eau d'élevage, mise au point de filtres biologiques, utilisation de substances électives, les élevages larvaires n'ont pu être menés à terme. A l'inverse, de bons développement larvaires ont été obtenus avec adjonction d'érythromycine mais ces résultats ne sont pas suffisamment reproductibles pour que cet antibiotique constitue un produit de substitution efficace.

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/1995/rapport-1568.pdf
http://archimer.ifremer.fr/doc/00000/1568/

Résumé : Selective breeding of shrimp for viral resistance is established for species like L. vannamei and L. stylirostris. However, selection for bacterial infection resistance is not documented. In New Caledonia, "Syndrome 93" is a vibriosis that affects cultured shrimps during the cool season with survival from 15 to 30%. Current practises for breeders rearing at low densities do not improve the resistance of the offsprings mainly because selection pressures for "Syndrome 93" are low. Even after the fifth generation, survival improvement is not significant.
La sélection génétique de lignées de crevettes résistantes à certains virus a démontré son efficacité en particulier chez L. vannamei et L. stylirostris. En revanche, la sélection de crevettes résistantes à une bactérie du genre Vibrio est peu documentée. En Nouvelle-Calédonie, le « Syndrome 93 », vibriose à V. penaeicida, affecte toutes les fermes de crevettes L. stylirostris lors des élevages de saison fraîche. Les survies en bassins de grossissement, de l’ordre de 40 à 60% dans un élevage sain, tombent à des valeurs de 15 à 30%. L’élevage de géniteurs à faible densité, s’il maximise les performances de reproduction, ne semble pas optimiser la qualité de la descendance du fait des faibles pressions de sélection qui s’exercent vis-à-vis du syndrome 93. Les améliorations significatives du nombre d’animaux survivant aux infections et aux épisodes de mortalité en bassin restent faibles en valeur absolue à la 5ème génération de sélection expérimentale en conditions d’élevage, mais sur le long terme la stratégie testée pourrait se révéler économiquement efficace.

Droits : 2005 Ifremer
http://archimer.ifremer.fr/doc/00117/22848/20658.pdf
http://archimer.ifremer.fr/doc/00117/22848/

Éditeur(s) : Actes de colloques Ifremer, Tahiti, French Polynesia, 20 Feb - 4 Mar 1989, n°9, chap. 62, pp.661-675
Résumé : The red drum Sciaenops ocellata (Linneaus, 1766) was introduced in Martinique (F.W.I.) from the United States (Texas and Florida). Thirteen intensive larval rearing attempts, from 7 batches of imported eggs, have been conducted for two years.

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/1989/acte-1434.pdf
http://archimer.ifremer.fr/doc/00000/1434/

Éditeur(s) : Actes de colloques Ifremer, Tahiti, French Polynesia, 20 Feb - 4 Mar 1989, n°9, chap. 5, pp.45-50
Résumé : In New Caledonia, there is no indigenous shrimp species for commercial aquaculture and it is necessary to control the complete cycle in captivity. Since 1973 and the creation of the Station d'Aquaculture de Saint-Vincent (S.A.S.V.), a joint project between IFREMER, France-Aquaculture and the territory of New Caledonia, nine species have been tested and for one of these, P. stylirostris , (introduced in 1980), we are now in a commercial scale production with the tenth generation obtained in captivity.

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/1989/acte-1496.pdf
http://archimer.ifremer.fr/doc/00000/1496/

Résumé : Two batches of red drum larvae were air shipped from hatcheries in the U.S.A. and stocked in two intensive tank experiments at densities oc 7 :.nd 2-3 larvae per liter. Food items include live rotifers, copepods, brine shrimps. squid and commercial fish pellets. Growth rates were similar in both experiments up to day 20 (12-1" mm) but differences in feeding schedules and an infestation by the dinoflagelate Amyloodinium sp. affected the growth from day 20 to 43 in the second trial. Significant mortalities occurred in the tanks during the first feeding period (days 2 to 7) and again from days 17 to 20 as the result of cannibalism. Survival between day 2 and day 44 was 44% in the first trial. Abnormal inflation of the swim bladder and infection with Amyloodinium sp. reduced the survival to 6-19% in the second.
Deux lots de larves du tambour rouge ont été transportés par avion depuis des écloseries aux USA et stockés dans deux essais en bac intensif aux densités oc 7 : nd 2-3 larves le litre. L'alimentation comprend les rotifères vivants, les copépodes, les artémias, les encornets et les boulettes de poisson commerciales. Les taux de croissance étaient pareils dans les deux expériences jusqu'au jour 20 (12-1''mm) mais des différences dans les programmes d'alimentation et une infestation par le dinoflagellé Amyloodinium sp. ont modifié la croissance à partir du jour 20 jusqu'au jour 43 dans le deuxième essai. Des mortalités importantes se sont produites dans les bacs pendant la première période d'alimentation (jours 2 et 7) et encore du jour 17 jusqu'au 20 à la suite d'un cannibalisme. La survie entre le jour 2 et le jour 44 était de 44 % dans le premier essai. Un gonflement anormal de la vessie natatoire et une infection de l'Amyloodinium sp. ont réduit la survie de 6 ¿ 19 % dans le deuxième.

Droits : 1988 Ifremer, UAG, Orstom
http://archimer.ifremer.fr/doc/1998/rapport-1914.pdf
http://archimer.ifremer.fr/doc/00000/1914/