A comprehensive alphabetical guide to the key concepts, chemicals, and solutions shaping ocean health today. Whether you're a student, educator, or curious citizen, this glossary will help you navigate the science of marine pollution.
A
Aquatic life — all organisms living in water, from microscopic plankton to the largest whales. Aquatic life is the first to feel the effects of water pollution.
Antifouling — coatings applied to ship hulls to prevent organisms like barnacles attaching. Historically used toxic tributyltin (TBT), now mostly copper-based, with ongoing research into non-toxic alternatives.
B
Bioaccumulation — the build-up of chemicals in a living organism over time. Fat-soluble pollutants like PCBs and PFAS accumulate in tissues faster than they can be broken down or excreted.
Biodiversity — the variety of living species on Earth and their interactions, including plants, animals, and fungi. Marine biodiversity is declining due to pollution, climate change, and overfishing.
Biomarker — a measurable biological response that indicates exposure to pollutants. For example, vitellogenin in male fish signals exposure to oestrogenic chemicals.
Bioplastics — plastics derived from biological sources. Not always biodegradable in marine environments — some persist just as long as conventional plastics.
C
Chemical fate — what happens to a chemical after it enters the environment: where it goes, how it transforms, and how long it persists.
Contaminants of Emerging Concern (CECs) — chemicals recently identified as potential environmental threats, including pharmaceuticals, PFAS, and microplastics.
Coagulation — a water treatment process that uses chemicals to clump together fine particles, making them easier to remove. An important step in removing some CECs from wastewater.
D
Dioxins — highly toxic persistent organic pollutants formed as by-products of industrial processes and incineration. They bioaccumulate in food chains and are linked to cancer and immune suppression.
E
Endocrine disruptors — chemicals that interfere with hormonal systems. Even at very low concentrations, they can affect reproduction, development, and behaviour in wildlife and humans.
Eutrophication — excessive nutrient enrichment of water bodies, typically from agricultural runoff, causing algal blooms that deplete oxygen and create "dead zones."
F
Forever chemicals — colloquial term for PFAS, reflecting their extreme persistence in the environment due to strong carbon-fluorine bonds.
G
Green chemistry — the design of chemical products and processes that reduce or eliminate hazardous substances. A key approach to preventing pollution at source.
H
Heavy metals — dense metallic elements like mercury, lead, and cadmium that are toxic to organisms. They enter oceans through industrial discharge, mining, and atmospheric deposition.
I
In silico — computer-based modelling and simulation used to predict how chemicals behave in the environment and interact with biological systems, reducing the need for animal testing.
In vitro — laboratory testing using cells or tissues outside a living organism. Used to study the effects of chemicals without whole-animal experiments.
M
Marine Strategy Directive — EU legislation requiring member states to achieve "good environmental status" in their marine waters, addressing pollution, biodiversity, and ecosystem health.
Meiofauna — tiny animals (typically 0.1–1mm) living in sediments on the ocean floor. They play crucial roles in nutrient cycling and are sensitive indicators of pollution.
Microplastics — plastic particles smaller than 5mm, from the breakdown of larger plastics or manufactured as microbeads. Found in every ocean environment studied.
N
Nanoparticles — particles between 1 and 100 nanometres. Engineered nanoparticles from consumer products are an emerging environmental concern, with largely unknown effects on marine life.
O
Organochlorines — a class of persistent organic pollutants including DDT and PCBs. Though largely banned, they remain in the environment and continue to bioaccumulate.
P
PFAS — per- and polyfluoroalkyl substances, a family of over 12,000 synthetic chemicals used in non-stick coatings, waterproofing, and firefighting foam. Extremely persistent and found globally.
Persistent organic pollutants (POPs) — toxic chemicals that resist environmental breakdown, bioaccumulate, and can travel long distances. Regulated under the Stockholm Convention.
Plastic additives — chemicals added to plastics during manufacturing, including plasticisers, UV stabilisers, and flame retardants. Many leach into the environment and are CECs in their own right.
R
Reverse osmosis — a water purification process that forces water through a semipermeable membrane, removing contaminants including PFAS. One of the most effective treatment technologies for CECs.
S
Stockholm Convention — an international treaty aimed at eliminating or restricting the production of persistent organic pollutants.
T
Tributyltin (TBT) — a highly toxic antifouling compound formerly used on ship hulls. Banned globally in 2008 after devastating effects on marine life, including imposex in sea snails.
Z
Zero pollution ambition — the EU's long-term goal of reducing pollution to levels no longer harmful to health or the environment, targeting 2050. Encompasses air, water, and soil pollution from all sources.
This glossary is a living document — as our understanding of ocean health evolves, so too will the terms and concepts covered here. Explore the full A New Formula resource library to dive deeper into any of these topics.
This article is part of the CONTRAST project, funded by the European Union under Horizon Europe. Views expressed are those of the author(s) only.