Live Transport of Striped Bass and Rainbow Trout Using a Hidrostal Pump

Abstract

Immediate and delayed (96 h) mortality, descaling, and injury rates of striped bass Morone sax‐atilis and rainbow trout Oncorhynchus mykiss that were inserted into the entrance (suction side) of a Hidrostal pump were compared to those of control fish that were inserted at the exit (pressure side). Comparisons were made in 158‐paired trials of striped bass and 86 trials with rainbow trout. The Hidrostal pump had no significant effect on immediate or delayed (96 h) mortality. Immediate mortality for striped bass and rainbow trout averaged 0.1 and 0%, respectively, and delayed mortality averaged 2.9 and 0.1%, respectively. Mean scale loss after passage for striped bass and rainbow trout was low (0.2 and 1.0%, respectively). Frequency of injury to the head, eyes, skin, and tins of pumped striped bass averaged 1.9, 2.8, 1.9, and 18.7%, respectively, and those of rainbow trout averaged 2.3, 0, 2.4, and 3.1%. No significant relationships were detected between fish mortality and pump speed, injected fish density, and debris load. Results suggest that large Hidrostal pumps have the capacity to transport live striped bass and rainbow trout at high density (1‐6 fish/L) with little mortality and body injury.

Pre-slaughter conditions, animal stress and welfare: current status and possible future research

“…In addition, different loading techniques are used for different species (e.g. pump, scoop or carpet) and do not induce the same level of stress (Wagner and Driscoll, 1994;Helfrich et al, 2004).…”

Validation of a model to predict fish passage mortality in pumping stations

“…It has to be said that few papers exist in literature that study injury and mortality of fish when passing through pumps (e.g., McNabb et al 2003;Helfrich et al 2004;Baumgartner et al 2009). Unfortunately, none of these studies attempt to identify the causes of fish damage nor relate their findings to the biological criteria for fish injury as derived within the framework of the AHTS program.…”

Injuries and deformities in fish: their potential impacts upon aquacultural production and welfare

“…Similar studies of large hidrostal pumps on other species of fish, such as splittail Pogonichthys macrolepidotus and Chinook salmon Oncorhynchus tshawytscha, have yielded comparable results (Helfrich et al 2001). Helfrich et al (2004) have therefore suggested that large hidrostal pumps be used to transport live fish at high densities. Greaves and Tuene (2001) have suggested that injuries can be minimised by reducing aggression around meal times.…”

“…One such pump is a hidrostal pump-a screw-type centrifugal impeller. Helfrich et al (2004) looked at the effects of live transport on mortality, descaling and injury rate in striped bass Morone Saxatilis and rainbow trout using this pump and found the frequency of eye injuries was 2.8% for bass and 0% for trout. Similar studies of large hidrostal pumps on other species of fish, such as splittail Pogonichthys macrolepidotus and Chinook salmon Oncorhynchus tshawytscha, have yielded comparable results (Helfrich et al 2001).…”

“…Further, manipulating diet quality and feed management practices can also reduce the prevalence of injuries. For example, providing fish with a balanced diet, containing sufficient mineral and protein requirements can reduce the Concrete versus cobbled raceways in rainbow trout (Bosakowski and Wagner 1994;Wagner et al 1996) Incorporate cobble substrates into salmonid raceways during construction Baffles in raceways in rainbow trout (Barnes et al 1996) Omit baffles during raceway construction Fish Physiol Biochem (2012) 38:61-83 75 Use a vacuum pump to transfer large numbers of fish (Grizzle et al 1992) Eye injuries Striped bass, rainbow trout (Helfrich et al 2004); splittail and salmon (Helfrich et al 2001) Use a vacuum pump to transfer large numbers of fish (Grizzle et al 1992) Epidermal injuries Rainbow trout an striped bass (Helfrich et al 2004) Use of vacuum pumps or turbine pumps at no more than 330 rpm…”