Water Quality in Tilapia Transport: From the Farm to the Retail Store

Abstract

Nile tilapia Oreochromis niloticus are routinely transported 1,200–1,400 km from Idaho to live markets in the greater Vancouver, British Columbia, area. Direct hauling mortality is typically very low, but significant economic losses occur during retail holding owing to a deterioration in physical appearance that results in fish that cannot be sold and their subsequent mortality. To address this problem, information was collected on hauling systems and protocols, holding systems and water management protocols, and water quality in the retail holding systems. During hauling, fish are exposed to high levels of dissolved oxygen, carbon dioxide, and bacteria. The transfer of fish from hauling systems to retail holding systems can subject them to rapid changes in temperature, dissolved oxygen, carbon dioxide, and pH. Problem areas in retail holding include low water temperatures, high un‐ionized ammonia concentrations, and elevated levels of gas supersaturation. Determination of the causes of high mortality in transportation and retail holding is difficult to clearly identify because of sampling difficulties and commercial restrictions; improvements in hauling protocols may depend on simulated hauling experiments followed by commercial verification.

Survival and behavioural responses of cool and warm water fish sedated with AQUI-S® 20E (10% eugenol) at high loading densities

“…To maintain consistent dissolved oxygen levels at ≥5 mg L −1 , compressed oxygen was continuously supplied and not adjusted while fish were in buckets. This resulted in saturated dissolved oxygen levels similar to those reported during commercial transport (Colt, Momoda, Chitwood, Fornshell & Schreck ). Prior to the addition of fish to buckets, a water chemistry meter (HACH ® Model: HQ40d; HACH Company, Loveland, CO, USA) was used to measure pH (HACH ® PHC101 probe), temperature, dissolved oxygen (HACH ® LDO101 probe) and total ammonia nitrogen (TAN) (HACH ® IntelliCAL Ammonia probe ISENH3181) in tank water.…”

“…While tilapia have been shown to be tolerant of similar high TAN levels during live transport (Colt et al . ), the application of AQUI‐S ® 20E in buckets resulted in similar ammonia levels to untreated controls.…”

<b>Reassessment of the suitable range of water pH for culture of Nile tilapia <i>Oreochromis niloticus</i> L. in eutrophic water

“…Consequently, there were low concentrations of toxic metabolites in the water, such as ammonia and H 2 S. However, Nile tilapia juveniles have grown surprisingly well on acidic organic-matter rich waters (pH < 6) in previous studies carried out in our laboratory (Nobre, Lima, & Magalhães, 2014;Rebouças, Lima, & Cavalcante, 2015;Silva, Santos Lima, Vale, & Carmo, 2013). Colt, Momoda, Chitwood, Fornshell, and Schreck (2011) have also found that O. niloticus could be transferred from pH 6 -7 to as low as pH 4.2 without problems. Due to the discrepancy between these results and those reported by El-Sherif and ElFeky (2009).…”

The application of phytoremediation Lemna perpusilla to increase the production performance of Nile tilapia Oreochromis niloticus in a recirculation system

“…Nevertheless, the dissolved oxygen condition in the L and TL treatment was in optimum condition. The optimum dissolved oxygen to support the survival of Nile tilapia was ranged from 3-5.6 mg/L (Colt et al, 2011).…”