Coral ReefsImportant ecological and economic services:•Act as natural barriers protecting coasts from erosion.•Provide habitats.•Support fishing and tourism businesses.
Coral Reefs DecliningDegradation and Decline Due to:•Coastal development•Pollution.•Overfishing.•Warmer ocean temperatures leading to coral bleaching: kill algae and thus the polyps.•Increasing ocean acidity from carbon dioxide.
Aquatic BiodiversityThe key factors determining biodiversity in aquatic systems are:●Temperature●dissolved oxygen content●availability of food●availability of light
Most of Earth is Covered With WaterAquatic marine life zones /Saltwater•Oceans and estuaries•Coastal wetlands•Coral reefs•Mangrove forestsFreshwater life zones•Lakes•Rivers and streams•Inland wetlands
Top Layer of Water: Marine & FreshwaterPlankton: free floating1.Phytoplankton:Primary producers for most aquatic food webs.2.ZooplanktonFeed on phytoplanktonZooplankton include single-celled protozoa to large invertebrates like jellyfish.