Multivariate methods in aquaculture research: Case studies of tilapias in experimental and commercial systems (original) (raw)
Related papers
1993. Multiple regression analysis of aquaculture experiments based on the-extended Gulland-and-Holt Plot": model derivation. data requirements and recommended procedures p. 13-23. In M. Frein, G. Hulata and D. Pauly (eds.) Multivariate methods in aquaculture research: case studies of tilapias in experimen. Abstract A method for the multivariate analysis of fish growth in aquaculture is presented.. It is derived from a linearized version of the von Bertalanffy growth function (VBGF), which, in its original form, is a bivariate regression termed the Gulland-and· Holt plot. Here, a version in form of a multiple regression equation is presented. The-extended Gulland-and-Holt plot" permits to identify and quantify the key variables controlling fish growth and permits the inclusion of these environmental and treatment variables to explain variance in growth of fish. Von BertalanITy growth parameters K and L~ are obtained, which contain the combined environmental effects on fish...
2004
Background Global increase in consumption of food fish is expected to take place predominantly in the water-rich, developing Asian countries, where population is growing and higher incomes are allowing the purchase of high value fisheries items. Fish production in the least developed countries, where fish protein is especially needed to prevent malnutrition, is a key element of food security in these regions and a critical area where innovative programs are needed to increase production. The aquaculture and Aquatic Resources Management (AARM) Program of the Asian Institute of Technology (AIT) aims to assist in improving food security by promoting aquaculture research, teaching and outreach. Since the inception of the Aquaculture Program 23 some years ago in 1981, there have been over 150 peer reviewed and professional publications on tilapia alone from AIT. An equal numbers of non-peer reviewed reports and publications have been generated. Considerable tilapia expertise has been 'incubated' and 'spawned' at AARM that includes a numbers of internationally recognized professionals, staff and students (360 MSc and Ph.D theses). More than 1, 200 individual practitioners have gone through the AIT-style training in tilapia hatchery and production since the start of the program. The impact of this large scale training of individuals and a literature generated has, at least in a small part, added to the continued success of aquaculture in the region. Recent aquaculture development in Asia has mirrored the introduction of tilapia and the growth of the industry. This growth is reflected in the research publications generated at AARM of AIT, although it is difficult to make judgments whether the publications/innovation came first and the industry followed or the other way around. At least publications and personalities reflect the passage of time. Aquaculture in some countries in Asia has gone through a rapid transformation from waste-fed semi-intensive to intensive culture systems. Publications have similarly followed this pattern of evolution. This paper explores the historical accounting of some of the AARM publications related to tilapia research and tries, to some limited extent, to draw parallels on the development of tilapia culture in Southeast Asian countries in particular. This paper however, while recognizing the importance of unpublished work in the generation of new knowledge in tilapia aquaculture, does not specifically address theses and dissertations generated at AIT with the assumption that important, seminal work finds its way to peer reviewed publications or to review papers. 1981-1985 According to personal accounts (C.K. Lin), about 50 Nile tilapia, Oreochromis niloticus, was presented to the Thai king by the emperor of Japan some 40 years ago although only half a dozen survived. The Thai king distributed tilapia seed to the Department of Fisheries which made its way to the ponds of AIT during the late 1970s. The Nile tilapia from Japan seems to have been the base population from which Asian tilapia aquaculture has evolved. It was about this time when Aquaculture as a curriculum and discipline was being recognized and established by academia in the region. There were limited numbers of aquaculture academic programs even in the more advanced western countries. AARM was one of the earliest in the region.
Statistical aspects of aquaculture research: one-and two-season cross-over designs
Aquaculture Research, 1998
One-and two-season cross-over designs are compared with completely randomized designs for their potential use in pond aquaculture experiments. Cross-over designs allow treatment comparisons to be made within the same pond, removing much of the between-pond variability. Different treatments are applied consecutively to the same pond. The one-season design involves splitting the season into two periods and applying different treatments in each period. The fish growth in each of the periods is compared taking account of both pond and period differences. The two-season design compares the harvest weight or growth over a whole season in consecutive seasons. Each of the designs is explained further. Data from uniformity trials are used to make these comparisons. Trials on the use of buffalo manure supplemented with urea and triple sulphate, which were completed in consecutive seasons, are used to verify the conclusions. The advantages and disadvantages of each design are discussed.
Stocking densities and feeding strategies in shrimp and tilapia polyculture in tanks
The objective of this work was to evaluate the performance of Pacific marine shrimp (Litopenaeus vannamei) and tilapia (Oreochromis niloticus), in a polyculture in tanks subjected to different stocking densities and feeding strategies, in comparison with monoculture. Two experiments were performed, at the same time, in a completely randomized design with three treatments and four replicates each. Treatments for experiment I were: monoculture with 10 shrimp per m² (10S:0T); polyculture with 10 shrimp and 0.5 tilapia per m² (10S:0.5T); and polyculture with 10 shrimp and 1 tilapia per m² (10S:1T). Shrimp was the main crop, and feed was provided based on shrimp biomass. Treatments for experiment II were: monoculture with 2 tilapia per m² (2T:0S); polyculture with 2 tilapia and 2.5 shrimp per m² (2T:2.5S); and polyculture with 2 tilapia and 5 shrimp per m² (2T:5S). Tilapia was the main crop, and feed was provided based on fish requirements. In the experiment I, tilapia introduction to shrimp culture resulted in lower shrimp growth and poor feed conversion rate. In experiment II, shrimp introduction to tilapia culture did not interfere with fish performance. Polyculture is more efficient with the combination of 2 tilapia and 2.5 or 5 shrimp per m² and feed based on fish requirements.
The Third International Symposium on Tilapia in Aquaculture
1996
Institut francais de recherche scientifique pour le developpement en cooperation Republique de Cote d'lvoire cro Centre de recherches oceanologiques Centre de cooperation Internationale en recherche agronomique pour le developpement With the cooperation of Cooperation franchise UB/TIB Hannover 89 117 105619 Centre technique de cooperation agricole et rurale Contents Foreword viii Preface ix A. KEYNOTE PAPERS
Aquaculture Research, 2005
Three approaches for multivariate analysis of ¢sh growth in aquaculture experiments with Nile tilapia (Oreochromis niloticus niloticus L.) based on the von Bertalan¡y growth curve are presented and compared. The approaches are: an extended Gullandand-Holt (GH) plot, a forced extended GH plot and a multilinear regression analysis for the growth parameter K. All three models provide valuable insight into the major environmental factors in£uencing the daily growth rate and explain 28^46% of the variance of the observed daily growth rate of the used data set. For all three methods, the modelled parameter is sig-ni¢cantly related to the net yield of Nile tilapia and can, therefore, be used for the predictive modelling of management scenarios. The extended GH plot loads the in£uence of environmental parameters upon L 1 , while the forced extended GH plot and Direct ¢tting of K load the in£uence on the growth parameter K. The latter is more in the tradition of aquaculture research. But the forced extended GH plot and Direct ¢tting of K can only be applied if L 1 of the cultured species is known, as the selected L 1 in£uences the variance in the regression variables.
Multivariate approach to the study of fish growth
Chemometrics and Intelligent Laboratory Systems, 1992
Nortvedt, R., Brakstad, F., Hansen, T., Lunde, T., and Skybakmoen, S., 1992. Multivariate approach to the study of fish growth.
Statistical aspects of aquaculture research: sample sizes for pond experiments
Aquaculture Research, 1998
The present paper illustrates the need for greater pond replication in pond experiments. It demonstrates that increasing the number of fish sampled in each pond will not reduce the number of ponds needed when treatment effects are estimated. Sampling bias, skew distributions and heterogeneous fish populations are discussed in relation to fish sample sizes. When it is impossible to increase the number of replicate ponds, several methods of accounting for the pond variability are suggested.
A White Paper on the Status and Needs of Tilapia Aquaculture in the North Central Region
Tilapias are grown in many states in the North Central Region (NCR), and the group has been designated as high priority by the North Central Regional Aquaculture Center (NCRAC) Industry Advisory Council (IAC). Tilapias are essentially only grown in indoor water recirculating aquaculture systems (RASs) in the region. Each year, priority research areas are identified by the NCRAC IAC and presented in consultation with the Technical Committee to the NCRAC Board of Directors (Board). Concern has emanated among the various NCRAC constituencies that work plans could potentially lose focus over time and not always address the most critical factors limiting the economical and sustainable production of important species in the region. After discussions were held among members of the various committees and the Board at its February 1998 annual meeting, it was decided that a white paper should be developed on tilapias. Disciplines Aquaculture and Fisheries Comments This article is from NCRAC White Paper series, January 2004. Used with permission.