Survey of antibiotic and pesticide residues in aquaculture products in the Philippines

A survey in the Philippines in the early and mid-1990s (Lacierda et al.,2008) revealed that more than 100 chemicals and biological products are used in aquaculture production starting from pond preparation until harvest including chemicals for disease prevention and control. The survey comprises groups of chemicals and some are namely, soil and water conditioners, fertilizers, pesticides, probiotics and feed additives. A probable increase in the usage (volume) and number of chemicals throughout the years could be inferred since world aquaculture production and the number of species for culture also increased (Tacon & Metian, 2008). For health reasons of consumers and the safety regulations imposed by importing countries on aquaculture products, there is a pressing need to survey the chemicals used in aquaculture at present. In line with the promotion of food safety awareness in the region with regards to fish, the objective of this survey was to determine levels of commonly used antibiotics and pesticides in aquaculture that maybe present in aquaculture products such as fish and shrimps

Important findings and recommendations on chemical use in aquaculture in Southeast Asia

Under the program of Fisheries Consultative Group of the ASEAN (Association of South-East Asian Nations) - SEAFDEC (Southeast Asian Fisheries Development Center) Strategic Partnership Mechanism, a research project entitled “Food Safety of Aquaculture Products in Southeast Asia” was implemented by SEAFDEC/AQD (Aquaculture Department of SEAFDEC) from 2010 to 2014 with the financial support of the Government of Japan Trust Fund V (GOJ-TF5). The objectives of the project were to 1) contribute to the establishment of guidelines on the production of safe aquaculture products; 2) determine the presence and levels of commonly used chemicals in aquaculture in aquaculture products; 3) compile and disseminate SEAFDEC guidelines on the use of antibiotics and chemicals in aquaculture; and 4) implement training course/workshop to promote food safety awareness in the ASEAN region. Along with the said objectives, research activities, particularly focusing both on withdrawal periods of antibiotics often used in aquaculture and on surveillance of chemical contaminants in aquaculture products and feeds, were implemented (in 2010-2014). In addition, knowledge and technologies on food safety of aquaculture products were disseminated to local and national government staff, practitioners, stakeholders, etc. through an international seminar (in January 2011) and an international training course (in November 2013). Furthermore, AQD organized The International Workshop on Food Safety of Aquaculture Products in the Southeast Asia – Challenges in Sustaining the Food Safety of Aquaculture Products in May 2013 to promote and influence the regional initiatives in securing wholesome and safe aquaculture commodities in the ASEAN region. The publication of this volume consolidates the activities of the project which AQD has pursued during the period of the GOJ-TF5. Although the title of this volume does not include the word “guideline,” this volume surely includes and refers to the ASEAN guidelines recently published with the title of Guidelines for the Use of Chemicals in Aquaculture and Measures to Eliminate the Use of Harmful Chemicals courtesy of the ASEAN secretariat based on the understanding of the collaboration between ASEAN-SEAFDEC, as well as the basic and new findings of AQD scientists accomplished through the research activities, which were not covered by the ASEAN guidelines. Although the food safety of aquaculture products would be strictly required in the ASEAN region in the future, this volume will make a great contribution to the requirement

Withdrawal periods of antibiotics, oxytetracycline, and oxolinic acid, in fish species cultured in the tropics

Food safety is one of the major concerns of products derived from aquaculture. Farm inputs, e.g. drugs and agrochemicals, introduced whether intentionally or unintentionally during culture, may contaminate and remain in the product and become a hazard to the consumers. Chemical hazards in aquaculture products, among them drugs used for the chemotherapy of bacterial infection in fish and other cultured aquatic animals present a negative impact in aquaculture. Fish farmers often result to this treatment in order to save their cultured stock when threatened with infection, although a general conception nowadays is the discouragement of its use, being considered only as the “last recourse.” Drugs, specifically antibiotics, have a long history of successful use in aquaculture (Alderman, 1980)

Survival and changes in the fine structure of selected tissues of Penaeus monodon Fabricius juveniles fed various carbohydrates

Penaeus monodon juveniles were reared on semipurified diets containing various carbohydrates (maltose, sucrose, dextrin, molasses, cassava starch, corn starch or sago palm starch). Significant differences were observed between the type as well as the level of carbohydrate in the diet on the survival of the juveniles. Results indicate that there does not seem to be any correlation between survival and the complexity of the carbohydrates

Atmospheric stilling leads to prolonged thermal stratification in a large shallow polymictic lake

To quantify the effects of recent and potential future decreases in surface wind speeds on lake thermal stratification, we apply the one-dimensional process-based model MyLake to a large, shallow, polymictic lake, Võrtsjärv. The model is validated for a 3-year period and run separately for 28 years using long-term daily atmospheric forcing data from a nearby meteorological station. Model simulations show exceptionally good agreement with observed surface and bottom water temperatures during the 3-year period. Similarly, simulated surface water temperatures for 28 years show remarkably good agreement with long-term in situ water temperatures. Sensitivity analysis demonstrates that decreasing wind speeds has resulted in substantial changes in stratification dynamics since 1982, while increasing air temperatures during the same period had a negligible effect. Atmospheric stilling is a phenomenon observed globally, and in addition to recent increases in surface air temperature, needs to be considered when evaluating the influence of climate change on lake ecosystems

Effects of different fat sources on the egg quality of grouper, Epinephelus suillus

Abstract only.The effect of different fat sources on the egg quality of grouper, Epinephelus suillus eggs was evaluated. Fish in three tanks, each containing 3 females and 1 male, were fed various types of feeds namely: trash fish (control), trash fish + cod liver oil (treatment 1) and trash fish + SELCO, a lipid emulsion containing high levels of highly unsaturated fatty acid (HUFA) (treatment 2). Approximately 77.9 million eggs spawned from January to October 1992 by the control group, 40.0 million by fish in treatment 1, and 36.4 million by the treatment 2 group. Egg production (0.45 million eggs/kg BW) among the control group was significantly higher than treatment 2. Egg production of treatment 1 (0.06-0.36 million eggs/kg BW) was not significantly different (P treatment 1 > treatment 2. There were no differences detected in the egg and oil globule diameters among the treatments. Crude protein and lipid levels of floating (good) and sinking (bad) eggs collected in February to March 1992, and August to September 1992 were similar in all treatments. Unfed larvae from treatment 1 survived until the fifth day after hatching while those in the control and treatment 2 groups lasted only until the third day. These results suggest that supplementation of cod liver oil and SELCO in the trash fish diet of E. suillus broodstock does not influence egg production, fertilization and hatching rates, and egg quality

Effect of dietary protein to energy ratios on growth, survival, and body composition of juvenile Asian seabass, Lates calcarifer

The optimum protein-to-energy (P/E) ratio for juvenile sea bass (body weight, 1.34 ± 0.01 g) was determined using practical diets in a 3 × 3 factorial experiment. Three protein levels (35, 42.5 or 50%) and three lipid levels (5, 10 or 15%) at a fixed carbohydrate level of 20% were tested. P/E ratios of the diets ranged from 104 to 157 mg protein/kcal. The fish were reared for 54 days in 60-liter flow-through tanks with seawater at 32 p.p.t. and 29 °C. Fish fed the diet containing 50% protein and 15% lipid (P/E ratio of 125 mg/kcal) showed the highest weight gain and specific growth rate. Those fed the diet with 42.5% protein and 10% lipid (P/E ratio of 128 mg/kcal) showed comparable growth rate and significantly better condition factor, protein efficiency ratio and apparent protein retention. Fish given diets containing 35% protein showed the poorest growth. Those fed diets with 5% lipid regardless of the protein content showed abnormal reddening of the fins, indicating essential fatty acid deficiency. Body fat increased with fat content of the diet and was inversely related to moisture. Fish given the diet containing 35% protein and 5% fat had the lowest body fat content and the highest ash and water content. The diet containing 42.5% protein and 10% lipid with P/E ratio of 128 mg protein/kcal was found to be optimum for juvenile seabass under the experimental conditions used in the study

Significant organotin contamination of sediment and tissues of milkfish in brackish water ponds.

Organotin pesticides, triphenyltin acetate or hydroxide have long been used as an inexpensive method to control the population of brackish water shails Cerithidea cingulata in the pond culture of milkfish (Chanos chanos Forsskal), and important food fish in the Philippines. The use of organotin pesticeds has been banned for several years now because the chemical renders the soil sterile, is nonbiodegradable and bioaccumulates, and is hazardous to humans. Despite the ban, the clandestine use of the pesticide in milkfish ponds continues to threaten the environment and humans

Leaf meals as protein sources in diets for milkfish Chanos chanos (Forsskal)

The protencial of partial replacement of fish meal protein with protein indigenous leaf meals in practical diets for milkfish, Chanos chanos (Forsskal) was studied. Five isocaloric (375 kcal/100 g diet), isonitrogenous (40% protein), and isolipidic (10%) diets were formulated to contain leaf meals from either swamp cabbage (kangkong, Ipomea reptans), sweet potato (kamote, Ipomea batatas), ipil-ipil (Leucaena leucocephala), and cassava (kamorng kahoy, Manihot esculenta), or a combination of swamp cabbage, sweet potato and cassava. The control diet contained fish meal and soybean meal as sources of protein while thw test diets contained fish meal, soybean meal, and leaf meals erplacing 15% of the fish meal protein. The protein sources were incorporated in levels that gives optimal essential amino acid patterns to the diets. Each diet was fed to reiplcate groups of fish (about 0.3 g) maintained at 20 ppt salinity and 29oC in a recirculating system for twelve weeks. Growth, feed conversion ratio (FCR), protein efficiency ratio (PER), and survival of fish fed the diet contaning cassava leaf meal showed the best groth FCR, PER and survival. the data sugest that these leaf meals can be used to partially replace fish meal in a diet for juvenile milkfish if the requirments for essential amino acids are met