Aquatic Health Program

Delta Smelt (Hypomesus transpacificus) Oocyte

Biomarker Analysis

Vitellogenin analysis (m-RNA/protein):

Estrogenic compounds, such as pharmaceuticals and pesticides, may cause sub-lethal reproductive effects on aquatic organisms. Vitellogenin, an egg yolk protein precursor found in the liver, is a well-known biomarker for the disruption of the endocrine system by estrogens and estrogen-mimicks in juvenile and male fish.   

Acetylcholine esterase (AChE) inhibition:

Organophosphate and carbamate insecticides inhibit the activity of the enzyme AChE in the nervous system. AChE inhibition is an excellent biomarker for measuring exposure and effect of these chemicals. It is routinely used to monitor humans at risk of OP or carbamate exposure.   

EROD (ethoxyresorufin O-deethylase) activity:

EROD activity is greatly enhanced by the presence of polycyclic aromatic hydrocarbons (PAHs), chlorinated hydrocarbons, and polychlorinated biphenyls (PCBs), and is a sensitive indicator of exposure to these chemicals.   


Metallothionein is a protein that binds to heavy metals. Its main cellular function is to render heavy metals non-toxic, therefore measuring metallothionein concentration in organisms exposed to heavy metals is a good indicator for heavy metal exposure.

Heat-shock protein (HSP) analysis:

Heat-shock proteins are proteins involved in protecting cells and tissues from environmental stressors. They are general stress indicators, and have been shown to be particularly useful in identifying the effects of temperature stress on aquatic organisms.