
Selenium (Se)
Chalcogens
Atomic Number: 34
Last Reviewed: 12/15/2024
Selenium is an essential micronutrient for many marine organisms, including fish and invertebrates. It is a component of selenoproteins, which are involved in antioxidant defense and thyroid hormone metabolism. However, maintaining appropriate selenium levels is critical, as both deficiency and excess can have adverse effects.
Natural Seawater Levels
Selenium concentrations in natural seawater are typically in the range of 0.04 to 0.12 µg/L. These levels can vary based on environmental factors and local biogeochemical processes.
Risks
Deficiency: Low selenium levels can impair antioxidant defenses and immune function in marine organisms, potentially leading to increased susceptibility to diseases.
Excess: Elevated selenium concentrations can be toxic, causing tissue damage and mortality in marine life. Toxicity thresholds are species-specific, but maintaining selenium within natural seawater levels is generally considered safe.
Relevancy
Biological Functions: Selenium is incorporated into selenoproteins that protect cells from oxidative damage and support immune function. In fish, adequate selenium levels are associated with improved growth and immune responses.
Microbial Interactions: Marine microorganisms play a significant role in the transformation of selenium, affecting its bioavailability and cycling within the ecosystem.
p >Ocean Values
Reference Name | Low | High | Optimal | Unit |
---|---|---|---|---|
Red Sea Ocean | 1.0000 | 2.0000 | 1.5000 | µg/L |
Caribbean Ocean | 0.7000 | 1.8000 | 1.1000 | µg/L |
Florida Ocean | 1.0000 | 2.0000 | 1.4000 | µg/L |
Regional Variations
Selenium concentrations in seawater can vary based on local environmental factors, such as proximity to selenium⁻rich sediments or anthropogenic inputs.
p >Dosage Recommendations
Target Level: Maintain selenium concentrations within the natural seawater range of 0.04 to 0.12 µg/L.
Adjustment: Supplementation should only be undertaken if a deficiency is confirmed through reliable testing, with careful dosing to avoid exceeding safe levels.
p >Handling
Testing: Utilize advanced analytical methods for accurate measurement of selenium levels, acknowledging the limitations of standard aquarium test kits.
Intervention: Only consider supplementation if a deficiency is confirmed, and proceed with caution to avoid toxicity.
Reef.Tools recommends: Maintain Selenium (Se) concentrations between 0.0000 and 0.0030 µg/L.
References
- "Selenium in a Saltwater Aquarium and Its Importance." Reef Pedia. Reefpedia
- Ivanenko, N. V. "The Role of Microorganisms in Transformation of Selenium in Marine Waters." Russian Journal of Marine Biology, vol. 44, 2018, pp. 87–93. SpringerLink
- Maher, W. A., et al. "Modelling Selenium Behavior in Aquatic Systems: A Review of Status and Developments." Environmental Science and Pollution Research, vol. 31, 2024, pp. 395–408. SpringerLink
- Benayoun, G., et al. "Influence of Environmental Factors on Selenium Flux in Two Marine Species." Marine Biology, vol. 105, 1990, pp. 347–351. SpringerLink
- Ullah, K., et al. "An Overview of the Ongoing Insights in Selenium Research and Its Role in Fish Nutrition and Fish Health." Fish Physiology and Biochemistry, vol. 43, 2017, pp. 1689–1705. SpringerLink
Difficulty
Rating: Moderate
Maintaining appropriate selenium levels requires careful management due to its low concentration in seawater and the potential for toxicity if over-supplemented.
Categorization
Element Type: Non-metal
Role: Essential Trace Element
Not Usually Deficient
Regular water changes with quality salt mixes usually replenish selenium levels adequately.
Essential
Selenium is a critical component of selenoproteins involved in antioxidant defense and immune function in marine organisms.
Aliases
Se