WP062 (JON-1117-821857) Use of fish-otolith chemistry as natural tags of habitat exposure.
Start time: 8:00 AM
Jones, C¹, Chen, Z², ¹ Center for Quantitative Fisheries Ecology, ODU, Norfolk, VA, USA² Laboratory for Trace Element Research, ODU, Norfolk, VA, USA
Animal ecologists have used tags in mark-recovery studies to estimate vital rates for over 100 years. The methods have mostly been developed by wildlife biologists who use physically-applied tags. Although applied tags have limitations, such as tag loss, tag mortality, and misreporting, they have been preferred over natural tags. However, with the development of new techniques, we now have reliable natural tags such as otolith chemistry and genetic markers. Otolith-chemical tags are especially valuable for resolving fine-spatial scale of habitat exposure. These natural tags provide greater precision and avoid the pitfalls of applied tags. However, these natural tags have important limitations such as the interaction between the geometry of growth rings and environmental-chemical uptake and the different chemistries of different otolith types. We use LA-ICP-MS and solution-based ICP-MS to illustrate these features.

WP063 (HAN-1117-748259) Micro-elemental analysis of statoliths as a tool for tracking stream origins of sea lamprey.
Start time: 8:00 AM
Hand, C¹, Ludsin, S², Marsden, J³, Fryer, B¹, ¹ University of Windsor- Great Lakes Institute for Environmental Research, Windsor, ON, Canada² NOAA- Great Lakes Environmental Research Lab, Ann Arbor, MI, USA³ Aiken Center, University of Vermont, Burlington, VT, USA
The establishment of invasive sea lamprey (Petromyzon marinus) throughout the Great Lakes basin (USA-Canada) has been costly both ecologically and economically, due primarily to predation mortality on important recreational and commercial salmonines such as lake trout. Despite continued, expensive (> $15 million annually) eradication efforts focused on barriers and lampricides, sea lampreys remain a nuisance, and leading cause of salmonid mortality in the Great Lakes. As regional fishery management agencies seek novel, cost-effective ways to control sea lamprey populations, we have begun exploring the possible application of sea lamprey statolith microchemistry as a tool to determine natal origins of parasitic and spawning phase lampreys. This could, in turn, help to focus control efforts on important production streams. Thus far, we have used laser-ablation inductively coupled plasma-mass spectrometry (LA-ICP-MS) to characterize stream-specific signatures of larval sea lamprey collected in > 30 spawning tributaries around Lake Huron and Lake Michigan. Herein, we present and discuss results regarding the overall effectiveness of this tool to discriminate among individuals, beginning at a large spatial scale (among watersheds), and then narrowing our focus within watersheds and finally within tributaries. We will discuss the potential utility of this technique to fisheries management agencies around the Great Lakes region.

WP064 (MEL-1117-743594) Nucleation and growth of teleost fish otoliths.
Start time: 8:00 AM
Melancon, S.¹, Fryer, B.¹, Gagnon, J.¹, ¹ GLIER (University of Windsor), Windsor, Ontario, Canada
Otoliths are the ear stones of fish and are mainly composed of calcium carbonate (CaCO₃). Their continual growth is recognizable as concentric rings of alternating opaque and translucent zones. Otoliths are considered not subject to resorption, and as such, only ontogenic and environmental factors will result in changes to their composition. It is believed that once an element has entered the otolith it remains chemically and isotopically inert. All these factors make otoliths unique recorders of the environment and fish migrations. Previous work has demonstrated that otoliths of some fish can be comprised of 3 different CaCO₃ crystalline structures, aragonite, calcite and vaterite which can greatly differ in their trace elemental composition. Teleost fish are found in a wide variety of warm and cool habitats over a vast range of territories (Canada and United States). This project investigates the nucleation of otolith biomineralization and the effects of age on metal inclusion in endolymph and otolith. The first goal is to determine how otoliths crystallize and if there is a catalyst that would help the crystallization. The central cores of larval yellow perch otoliths are optically distinct compared to the surrounding core otolith material. Other researchers found that the core concentrations of Mn and Fe are higher than in the edges (Brophy et al. 2004). The literature does not provide any spectroscopic data on the origin of that material. This study will provide the first high resolution spectroscopic evaluations of the nucleating material of otolith cores and first trace metal composition of the endolymph. The second part of this project will evaluate variations in metal composition of endolymph and otolith with fish age. Otoliths and their endolymph will be analyzed using a combination of Scanning Electron microscopy (SEM), X-ray Absorption Fine-Structure Spectroscopy (XAFS) and Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry (LA-ICP-MS).

WP066 (FRI-1117-809276) Alkali element uptake in otoliths: a link between geography and otolith microchemistry.
Start time: 8:00 AM
Friedrich, L.¹, Halden, N.¹, ¹ University of Manitoba, Winnipeg, Manitoba, Canada
Otoliths, the hard calcareous (typically aragonite) structures located in the inner ear of teleost (bony) fish, are used to determine age, life history events, and environmental conditions of fish and fish populations. Strontium is a common substituent for calcium in otolith aragonite and is used to establish migratory behavior of fish. Zinc has also been reported in otoliths and may be linked to proximity to mine tailings or used as a proxy for fish size. Carbonate minerals in general are capable of incorporating a wide range of trace elements, therefore it might be anticipated that biogenic carbonates may also incorporate an equally wide range of elements. In this work we have examined otoliths taken from fish in the vicinity of rare element pegmatites in eastern Manitoba, Canada using LA-ICP-MS. Lithium, cesium, and rubidium were detected in the otoliths at levels ranging from 5 to 80 ppm; strontium and sodium are present up to 950 and 2435 ppm, respectively. The levels of abundance vary, sometimes in correspondence to the annular structure of the otoliths, suggesting there is some periodicity to their incorporation. Li-, Cs- and Rb-bearing minerals, including carbonates, are common within the rocks of the area; moreover these minerals are easily weathered and, as such, would release elements to the aqueous environment. This is the first reported detection of these elements in otoliths suggesting there may be a link between a fish's geographic environment and the microchemistry of its otoliths. Such information may be used to characterize and monitor lacustrine environments over a period of time.