Fish lab
The fish identification and processing lab is located at the Center for Aquatic Biology and Aquaculture (CABA).
The CABA lab focuses on larval fish, mysid, zooplankton and copepod sampling and identification. Samples collected in the field are brought to CABA, picked through for fish, mysid and other organisms for identification. The Hobbs Lab larval studies focus on looking at San Francisco Bay tributaries that may be good spawning areas for Longfin smelt.
Otolith lab
The otolith lab is located in the AcSurge building
Sample preparation
Our lab has several facilities for otolith extraction, polishing, and imaging used for age and growth analysis. Otolith can then be mounted on slides and analysed for their elemental and isotopic composition in collaboration with the Center for Plasma Mass Spectrometry, University of California, Davis.
Age and Growth analysis
We have experience with daily ageing from otolith micro-increments and annual ageing with otoliths, scales and fin rays. We use a state of the art laser scanning con focal microscope for daily otolith ageing providing high resolution images and precise age estimates. We use Image Pro digital image analysis software to measure age increments for growth rate and pattern analysis.
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- Part of the otolith lab
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- Wilson sanding a Delta Smelt Otolith
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- Sample boxes
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- Delta Smelt otolith
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- Sanded Longfin Smelt otolith
Analytical facilities
We collaborate directly with the UC Davis Interdisciplinary Center for Inductively-Coupled Plasma Mass Spectrometry. We specialize in laser ablation ICP-MS for quantifying trace and minor element chemistry in fish otoliths, fin rays and scales. The center uses a New Wave Nd:Yag 213nm laser system coupled to a 7500a Agilent quadrupole ICP-MS, providing concentrations in the parts per million to parts per billion range. The New Wave laser system can provide a variety of laser configurations with a circular laser spot shape and diameters ranging from 5 to 120 micron. Typical parameters for fish otoliths are in the 20-40 diameter providing ~weekly resolution.
We are also directly involved in the development and application of laser ablation multi-collector ICP-MS to quantify isotopes of strontium in the parts-per-billion range. The use of strontium isotope ratios has distinct advantages over trace element chemistry for determining natal origins and migration histories of freshwater fishes in that chemical signatures in waters are not physiologically regulated by the fish and often directly matches otolith chemistry, simplifying matching fish to natal habitats.
