Determining Residence Patterns of Rainbow Trout Using Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) Analysis of Selenium in Otoliths

Abstract

Toxicological studies are often hampered by concerns of fish residency in the industrial effluent being evaluated. Contaminants in muscle or visceral tissue are useful indicators of recent exposure, but depuration, metabolic transformation, and tissue recompartmentalization of contaminants makes their use as temporal markers tenuous. Otoliths are metabolically stable and can provide temporal resolution for exposure to some elements that are incorporated into their calcified structure, including the divalent cations Sr, Zn, and Mn. Here we provide the first determinations of selenium, an anion in biological systems, in the otoliths of rainbow trout captured from a site receiving runoff with elevated selenium from a coal mine operation. Concentrations of selenium in annual growth zones of otoliths suggest that fish from the mine-impacted system are recent immigrants from nearby reference streams not receiving selenium-bearing effluent.

Selenium detected in fish otoliths: a novel tracer for a polluted lake?

“…Although selenium can be measured in otoliths with ICP mass spectrometry (Palace et al 2007), it is very difficult. Synchrotron-based SXFM is sensitive to Se and has few interferences, making it an ideal instrument for Se quantification.…”

Food chain transfer and exposure effects of selenium in salmonid fish communities in two watersheds in the Canadian Rocky Mountains

“…Fish movements in lotic systems with good hydrological connectivity are an important potential factor in producing these Se concentration patterns (Holm et al 2005;Orr et al 2012). Variable use of Se-contaminated habitats by prespawning adult fish has been confirmed in studies of adult trout residency in Elk and McLeod river streams (Friedrich et al 2011;Palace et al 2007). While Se tissue concentrations can reflect dietary concentrations almost immediately, they can take weeks or months to reach equilibrium (Stewart et al 2010).…”

Mercury in fish that are of dietary importance from the coasts of Sinaloa (SE Gulf of California)

“…In one case, Hg levels in muscle and liver were comparable. Timing of Hg exposure can be a relevant issue in terms of tissue distribution, muscle or viscera are indicators of recent exposure, conversely, liver is indicator of past exposure, but other factors as metabolic transformations and depuration may alter this pattern (Palace et al, 2007). The high concentration of mercury in the hepatic tissue of fish might be related to the occurrence of low molecular weight (metallothionein-like) proteins (Hidalgo et al, 1985) since they participate in the detoxification of metals in fish (Kojadinovic et al, 2007).…”