A progressive approach to shrimp health management

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How water quality management, low stocking densities and the use of specialised feeds can consign the use of antibiotics in shrimp farming to history. The 400-hectare Sanolmedo shrimp farm in Ecuador ha been antibiotic-free since its inception over a year ago. The farm, located at the end of a long jungle road in Taura, is Corporación Lanec’s newest and most ambitious project to date and a select group of delegates from the nearby GOAL conference were able to visit this week to find out [...]

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How does rainfall affect shrimp pond water parameters?

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Problems in shrimp farming usually occur during severe drought or heavy rainfall. Observations confim major losses occur mainly during periods of rainfall. In the last two years, we have had droughts brought about by El Niño. The US Climate Prediction Center and the International Research Institute for Climate and Society have issued an announcement that there is a 60% chance of La Niña developing in the last quarter of 2016. In contrast to El Niño, with La Niña we will [...]

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What Happens in Shrimp Ponds During Heavy Rains?

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• Water temperatures, oxygen, pH, alkalinity and salinity drop. • Phytoplankton crashes occur. • Organic material accumulates on pond bottoms. • Strong winds stir up the bottom sludge. • Toxic levels of hydrogen sulfide (H2S) are released. • Pathogenic bacteria replace beneficial bacteria. • The noise of rain pounding on the surface stresses the shrimp. • Shrimp molt because of the lower pH and phytoplankton changes. Outcomes: • Mortalities occur because of the changes in water quality, stress and pathogens. • Feed consumption drops. • Shrimp migrate to the bottom [...]

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Zooplankton and Phytoplankton

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Zooplankton Zooplanktons are planktonic animals that range in size from microscopic rotifers to macroscopic jellyfish. The distribution of zooplankton is governed by salinity, temperature and food availability in the environment. The smallest zooplankton can be characterized as recyclers of water-column nutrients and often are closely tied to measures of nutrient enrichment. Larger Zooplanktons are important food for forage fish species and larval stages of all fish. They also link the primary producers (phytoplankton) with larger or higher trophic-level organisms. The zooplankton community [...]

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Massachusetts – John Sackton on EHP

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At the Global Aquaculture Alliance’s GOAL shrimp session in Vancouver, British Columbia, Canada (October 2015), a panel of shrimp experts talked about the microsporidian Enterocytozoon hepatopenaei, a spore-forming fungal parasite, and how it might affect the global shrimp supply.  John Sackton, Editor and Publisher at Seafood.com (an online, subscription-based, fisheries news service) prepared the following report based on interviews with a number of the shrimp experts, who spoke on the condition that they would not be quoted by name. When [...]

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Problems in shrimp culture during the wet season

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Recently, many farmers have faced the problem of fluctuations in salinity and temperature causing shrimp diseases; particularly yellowhead, white spot and luminescent bacteria that generally cause farmers to lose their crops. They have also had problems with stunted growth or black gill. Many of these problems can be overcome. Most farmers generally prefer to stock shrimp in the wet season, as they believe there are fewer problems than in the dry or cold seasons. However, culture in the wet season [...]

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Defining Ranges For Water Quality Variables Presents Complex, Challenging Process

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Summary: The creation and application of reference tables for acceptable concentration ranges of physical and chemical water quality variables for culture organisms would be challenging due to the differing tolerances found among the many farmed species. Factors such as water temperature, water chemistry (pH and dissolved oxygen and carbon dioxide levels), exposure time, physiological condition and size of the test animals can all affect tolerance. Especially in ponds, temperature and other water quality variables fluctuate on a daily basis, as [...]

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Recirculating Aquaculture Technology – Part II. Starting Biofilters

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Summary: To start a biofilter together with a source of nitrifying bacteria, you must provide the conditions that will encourage the growth of the bacteria. The basic process requires initial preparation of water chemistry, adjustment of alkalinity to support bacterial growth and the addition of ammonia. Introducing nitrifying bacteria can accelerate the biofilter acclimation process. Ammonia, nitrite, pH, temperature and alkalinity levels should be monitored regularly in a standardized fashion. When starting a biofilter, it is very important to follow [...]

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A Brief History of Shrimp Farming in Vietnam

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Shrimp News: The March 2015 edition of World Aquaculture, the quarterly magazine of the World Aquaculture Society, contains an excellent article by several Vietnamese researchers (see Source below) on the history and current status of shrimp farming in Vietnam.  Here, I report on the history.  I’ll cover the current status elsewhere on this webpage. With diversification of species, systems and organizational structures—hatchery and farm production of marine shrimp in Vietnam has been growing rapidly for several decades, contributing significantly to [...]

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India: New disease worries vannamei shrimp farmers

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After achieving a record production of shrimp, which allowed the value of seafood exports from India to grow by 14 per cent yoy in the nine months ending December 2014, the industry fears that the disease known as RMS (Running Mortality Syndrome) may affect the production of vanamei shrimp in the new fiscal year. The main affected states are Andhra Pradesh and Tamil Nadu, in the southern east coast, which are the major producers of this variety of shrimp, and the top earners in the seafood export [...]

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