Introduction

• Topic: Human impacts on ecosystems

• Focus on heavy metals, mercury, and litter in aquatic ecosystems

• Learning objective: Describe impacts of human activities on aquatic ecosystems

• Essential knowledge statements: Heavy metals in drinking water, mercury toxicity, litter in aquatic systems

Heavy Metals in Drinking Water

• Heavy metals in drinking water: lead, mercury, arsenic, copper, cadmium, chromium

• Sources: mining, smelting, chemical production, wastewater, fossil fuel combustion

• Health impacts: cancer, organ damage, neurological issues

Mercury Poisoning

• Mercury causes neurological damage

• Conversion to toxic methylmercury by bacteria

• Bioaccumulation and biomagnification in food chain

• Case study: Minamata, Japan - neurological damage in humans and animals

Plastic Waste Threat

• Plastic waste in waterways and oceans

• Impacts on wildlife: ingestion, blockage, entanglement, suffocation

• Need for responsible waste disposal to protect marine life

Toxins from Litter

• Microplastics release toxins in two ways

• Endocrine disrupting chemicals and pesticides

• Impact on plankton and other organisms in the food chain

Conclusion

• Heavy metals in drinking water lead to health issues

• Mercury converted to toxic methylmercury in aquatic systems

• Litter, especially plastic, harms wildlife through ingestion and entanglement

• Importance of understanding and mitigating human impacts on ecosystems