Mercury and trace elements in crayfish from northern california

Area of Science:

• Environmental toxicology
• Aquatic ecology
• Food safety

Background:

• Crayfish are a food source in California watersheds.
• Mercury contamination in aquatic ecosystems is a public health concern.
• Understanding mercury and trace element bioaccumulation in crayfish is crucial for risk assessment.

Purpose of the Study:

• To quantify mercury and trace element levels in two crayfish species from California.
• To compare concentrations between crayfish tissues (tails vs. carcasses).
• To assess potential health risks associated with crayfish consumption based on contaminant levels.

Main Methods:

• Collection of Pacifastacus leniusculus and Procambarus clarkii from Cache and Putah Creeks.
• Analysis of crayfish tissues for mercury and various trace elements.
• Comparison of contaminant concentrations between species, sexes, sites, and tissues.

Main Results:

• Trace element concentrations were generally higher in crayfish carcasses, but within safe limits.
• Mercury concentrations showed no significant differences among sites, sexes, or species in tails.
• Methylmercury concentrations in crayfish tails (0.156-0.256 microg/g) surpassed levels recommended in health advisories for fish and crayfish consumption in these watersheds.

Conclusions:

• Methylmercury in crayfish tails from Cache and Putah Creeks poses a potential health risk to consumers.
• While trace elements were not found at harmful levels, mercury bioaccumulation necessitates further investigation and consumer advisories.
• Management strategies may be needed to mitigate mercury contamination in these important aquatic food sources.