Mercury’s Impact:
Traditionally considered a healthy source of lean protein, omega-3s, and essential nutrients, seafood increasingly carries mercury and microplastics through the world’s oceans-an unsafe condition for humans and wildlife alike. This article provides exploration regarding the dangers of mercury and microplastics accumulation from your seafood, and what can be done to make choices a little safer.
What is Mercury, and How Does it Enter the Ocean?
Mercury is a naturally occurring element, but human activities, especially coal burning, mining, and industrial processes, do release large amounts into the atmosphere. These settle into oceans and waterways, and the mercury is transformed into methylmercury-a toxic compound which bioaccumulates into aquatic food chains.
How Does Mercury Accumulate in Seafood?
Mercury biomagnifies up the food chain as follows:
- Phytoplankton take up methylmercury from the water.
- Small Fish feed on phytoplankton and bioaccumulate mercury in their flesh.
- Predatory Fish, like tuna and swordfish, prey on smaller fish and because of biomagnification take in higher levels of mercury within their bodies.
- The impact is that larger, long-lived species tend to contain unsafe levels of mercury.
Health Risks of Mercury Exposure
Consumption of sea food contaminated with mercury is known to pose health risks:
- Neurological Damage: Mercury interferes with the development of the brain, especially in fetuses, infants, and young children.
- Cardiovascular Problems: High levels of mercury have been associated with heart disease and high blood pressure.
- Immune System Suppression: Long-term exposure suppresses immune response.
- Reproductive Issues: Mercury may relate to lower fertility and damaged fetal development during pregnancy.
The Increasingly Troubling World of Microplastics in Seafood
What Are Microplastics?
Microplastics are defined as small plastic particles less than 5mm in size, originating either from the breakdown of larger plastics or manufactured as microbeads for cosmetics, cleaning products, and industrial processes. These are now ubiquitous marine pollutants.
How Do Microplastics Accumulate in Seafood?
General ways microplastics may reach the ocean include littering, poor waste management, and wastewater systems. They start being ingested from simple plankton up the food web.
Key Pathways of Ingestion of Microplastics:
- Filter Feeders: Most mollusks, such as mussels and oysters, filter in the microplastics along with plankton.
- Predatory Fish: The fish that feed upon the small prey items accidentally tend to consume microplastic.
- Human Exposure: Human beings get exposed to these microplastics when they eat seafood containing the microplastic particles stored in the animal tissues.
Health Risks of Microplastics
Although still under research, the evidence of microplastics in our food is raising an alarm in the following ways:
- Chemical Contaminants: Microplastics can carry harmful chemicals like BPA and phthalates, which disrupt endocrine functions.
- Tissue Damage: Microplastics fragments can damage gut tissues and trigger inflammation.
- Unknown Long-Term Effects: Scientists are still studying how microplastics affect organs and overall health over time.
Seafood Safety Tips: Protecting Your Health
Choose Low-Mercury Options:
Choose fish lower on the food chain, which generally have lower levels of mercury. These include:
- Salmon
- Sardines
- Tilapia
- Pollock
Limit High-Mercury Seafood:
Avoid or limit the following species:
- Tuna (especially albacore and bigeye)
- Swordfish
- King mackerel
- Shark
Choose Wild-Caught Over Farmed:
Wild-caught fish generally have less contamination with antibiotics and microplastics than farmed fish, although it is indeed dependent on the region.
Check Seafood Guides:
Know your safe and sustainable seafood options with the help of a tool like the Seafood Watch Guide or EPA guidelines. Be Careful with Shellfish. Knowing that filter feeders like mussels and oysters tend to concentrate microplastics, enjoy them in moderation and from trusted sources.
The Environmental Implications
- Damaging Marine Ecosystems: Both mercury and microplastics interfere with marine food chains, therefore degrading biodiversity and aquatic health.
- Financial Implications: From Fisheries and Tourism to industries, affected fisheries result in the deterioration of enterprises depending on a clean marine environment.
- Climate Change Links: Mercury emissions and manufacture of plastic are related to high usage of fossil fuel, accelerating climate change.
Mercury and microplastics in seafood are stark reminders of how human activities can affect both environmental and human health. By making better choices and encouraging systemic changes, we can reduce these risks for a more sustainable future that will protect marine ecosystems and ourselves.
Farhana Islam
Agriculturist, Researcher
Fisheries Resource Management, CVASU
