IB Environmental systems and societies 4.3 Aquatic Food Production Systems Key Definitions

Aquaculture is the controlled farming of aquatic organisms like salmon, tilapia, catfish, oysters and mussels.

Biodiversity refers to the variety of life in an ecosystem, encompassing different levels of biological organization.

Bottom trawling is an industrial fishing method that drags heavy nets along the seabed, capturing bottom-dwelling species but causing severe damage to habitats and high bycatch rates.

Carbon sequestration is the process of capturing atmospheric carbon dioxide (CO₂) and storing it in solid or liquid form.

Carrying capacity is the maximum number of individuals of a species that an environment can sustainably support over time.

Citizen science is the involvement of the general public in scientific research, particularly in collecting, analyzing, and reporting data on environmental systems.

Coral bleaching is when corals expel the symbiotic algae living within their tissues due to stress from heat, pollution, or acidification, causing them to turn white.

An oceanic area extending 200 nautical miles from a country’s coastline where that nation has exclusive rights over marine resource use.

A fish stock refers to a population of a particular species of fish that is managed as a unit. It may include all individuals in a defined geographical area.

Ghost fishing is the unintended capture and death of marine organisms caused by lost or abandoned fishing gear that continues to function passively in the environment.

Macrophytes are large aquatic plants visible to the naked eye.

Marine Protected Areas (MPAs) are designated regions of the ocean where human activities, such as fishing and resource extraction, are restricted or prohibited to conserve marine ecosystems and biodiversity.

The Maximum Sustainable Yield (MSY) is the highest possible annual catch that can be harvested indefinitely without depleting a fish population.

Natural capital refers to the total stock of natural resources (both renewable and non-renewable) that provide ecosystem services benefiting humans and the environment.

Nutrient loading refers to the addition of nutrients (natural or human-induced) into a water body, affecting productivity.

Nutrient mixing refers to the vertical movement of water that redistributes dissolved nutrients (like nitrates and phosphates) throughout the water column.

Ocean acidification is the process by which the ocean becomes more acidic due to increased levels of dissolved carbon dioxide.

The photic zone is the upper layer of a body of water that receives enough sunlight to support photosynthesis.

Phytoplankton are microscopic organisms capable of photosynthesis

Primary productivity is the rate of production of biomass using an external energy source and inorganic sources of carbon and other elements.

A thermocline is a layer in a body of water where temperature decreases sharply with depth, restricting vertical movement and mixing.

Turbidity measures water transparency based on suspended particles (sediments, plankton, pollutants).

Upwelling refers to the vertical movement of deep, cold, nutrient-rich water to the surface due to the displacement of surface waters by wind.