Biomagnification and Bioaccumulation

Published on 04 Apr 2025

• Biomagnification is the condition in which a pollutant or toxin increases as it moves through the food chain. It can be considered as the result of bioaccumulation.

• Example: Species like Shark, Swordfish, Tuna, King Mackerel, or Tilefish contain proportionally larger levels of toxic mercury than smaller fish and shellfish.

• Bioaccumulation refers to the process by which a chemical substance accumulates in the tissue of an organism over time. This can occur through exposure to contaminated food or water, or through absorption of chemicals from the surrounding environment.

• Example: Car emission chemicals building up in birds.

Causes of biomagnification and bioaccumulation

• Agriculture: The pesticides and fertilizers which contain heavy metals are released into soil and water resources.

• Example: Bioaccumulation of Organophosphate Pesticides in Agricultural Runoff

• Industries: Industrial waste with high levels of toxins is another cause of biomagnification.

• Example: Coal combustion and metal processing, release mercury into the atmosphere

• Mining activities in the ocean: Mining in the deep ocean to extract metals also poses a threat to life. It generates selenium and sulfides which destroy coastal ecosystems.

• Example: Release of mercury by underwater gold mining.

• Global transport: Global marine transport can cause the release of many heavy metals which is a danger to living organisms.

• Example: Use of leaded gasoline resulting in lead emission to the atmosphere.

Impacts of biomagnification and bioaccumulation

• Impact on top predators: Biomagnification affects all the organisms but animals higher up in the chain are more impacted. This can result in species decline and Extinction.

• Example: The insecticide DDT which gets accumulated in zooplanktons and finally reaches fish-eating birds.

• Ecological disruption: It disrupts the ecosystem by disturbing the balance of predator-prey relationships.

• Example: Bioaccumulation of methylmercury affecting the ability of predatory fish to hunt and capture prey.

• Biodiversity loss: Species that are sensitive to pollutants may be unevenly affected, leading to changes in species composition.

• Example: DDT biomagnification occurred in the United States in the 1950s and 1960s, when populations of bald eagles began to decline rapidly.

• Impact on aquatic ecosystems: It is highly susceptible to biomagnification mostly due to water-soluble pollutants. 

• Example: Higher mercury level concentration is found in Mediterranean blue sharks.

• Threat to human health: Humans are highly vulnerable to elevated levels of pollutants through the consumption of food.

• Example: DDT, which enters the human body through the food chain can get deposited as adipose tissues, which when oxidized, release toxins into the body. This affects neurological development, reproductive health etc.

• Economic impact: Biomagnification can potentially disrupt the economic progress of a country.

• Example: Decline in fish populations due to biomagnification can affect fisheries.

Government initiatives and policy measures

• Implementation of waste management rules: The government has introduced and revised different waste management rules to address waste disposal. 

• Example: Solid Waste Management Rules 2016, Plastic Waste Management (Amendment) Rules,2022, Waste to energy

• Water and Air quality regulations: The government has implemented several water and air quality standards to minimize the discharge of pollutants into water and the atmosphere.

• Example: Water (Prevention and Control of Pollution) Act, 1974, Environment (Protection) Act, 1986, National Clean Air Programme.

• Chemical Management and Regulation: The government of India has further reinforced the legal framework on chemical safety and management of chemical accidents by enacting new rules such as MSIHC Rules, EPPR Rules, SMPV Rules, CMV Rules, Gas Cylinder Rules, Hazardous Waste Rules, Dock Workers Rules and by way of amendments to them.

• National Biodiversity Action Plan: It is India’s response to its international commitments under the Convention on Biological Diversity. It ensures the sustainable use of biological resources and the conservation of biodiversity.

• International conventions and agreements: India has signed various international agreements to address environmental problems.

• Example: The Stockholm Convention on Persistent Organic Pollutants (POPs) aims to eliminate or restrict the production and use of various pollutants that can lead to bioaccumulation. 

International initiatives

• International conventions: Nations come together to share the best practices and adopt common policies to address environmental issues including bioaccumulation.

• Example: Minamata Convention on Mercury which sets guidelines for the reduction of mercury emissions and the use of best practices to minimize mercury exposure.

• International Maritime Organization Regulations: IMO is the agency that is responsible for the safety and security of shipping and the prevention of marine and atmospheric pollution by ships. It provides regulations to control the discharge of harmful substances.

• Example: Ballast Water Management Convention

• GloLitter Partnerships: It is a project between the Government of Norway, IMO and FAO aiming to reduce marine litter.

Way Forward

• Strengthening regulatory framework: Strengthening and enforcing the regulatory framework from grassroots to international levels. It is important to check that these regulations are based on the latest scientific information.

• Research and Monitoring: It is important to understand the sources, pathways, and mechanisms of bioaccumulation as well as conducting regular monitoring programs to understand the health of the ecosystem.

• Encouraging Alternative and Sustainable practices: Adoption of sustainable practices will help to tackle the problem of bioaccumulation and biomagnification. For example, shifting to organic farming rather than depending on conventional agricultural practices.

• Public awareness and participation: Encouraging citizens to get involved in decision-making and strengthening their participation in government programs.

• Example: Eco–Vizag – Zero Plastic campaign underscores the commitment of the local authorities and the citizens of Visakhapatnam to create a cleaner and greener city.

• International cooperation: Strengthening transboundary collaboration and cooperation to address environmental issues is the need of the hour.

Tags:
Environment

Keywords:
Ecology Ecosystem Biomagnification Bioaccumulation

Syllabus:
General Studies Paper 3

Topics:
Environment and Climate Change