ESS topic 4.3 Aquatic food production systems (new syllabus)

Phytoplankton (4.3.1)

Microscopic aquatic organisms capable of photosynthesis that form the foundation of many aquatic food webs. For example, diatoms in the Southern Ocean support the Antarctic marine ecosystem.

Macrophytes (4.3.1)

Visible aquatic plants growing in or near water. For example, water lilies in the Okavango Delta provide habitat for fish and other organisms.

Overexploitation (4.3.4, 4.3.5)

Harvesting a renewable resource at a rate faster than it can naturally replenish. For example, Atlantic cod stocks off Newfoundland collapsed in the early 1990s when harvests exceeded reproduction rates.

Bottom trawling (4.3.4)

A fishing method that drags heavy nets across the seafloor, catching everything in their path. For example, this kind of fishing in the North Sea has damaged benthic habitats and reduced biodiversity.

Ghost fishing (4.3.4)

Continued capture of marine animals by abandoned, lost, or discarded fishing gear. For example, lost crab pots in the Chesapeake Bay continue to trap marine life for years after being abandoned.

Maximum sustainable yield (MSY) (4.3.6, 4.3.13, HL)

The highest rate at which a renewable resource can be harvested without reducing its ability to regenerate. For example, Pacific salmon fisheries aim to sustain harvests indefinitely through careful monitoring and quota systems.

Marine protected area (MPA) (4.3.9)

A designated zone where human activity is restricted to conserve the natural environment. For example, the Great Barrier Reef Marine Park in Australia covers over 344,000 square kilometers.

Aquaculture (4.3.10)

The farming of aquatic organisms under controlled conditions. For example, Norway's salmon farms produce over 1.3 million tonnes of Atlantic salmon annually.