Freshwater Life Zones Source Transition Lotic Systems- Floodplain Running bodies of water (streams and rivers) 3 zones Source zone Fast-flowing, cool, high DO content, little to no sediment Trout fallen organic matter Transition zone Mid-velocity, slightly warmer than source zone, moderate DO content, moderate sediment Sockeye salmon and black bass algae and moss Floodplain zone Slow to stagnant, warm, little DO content, excessive sediment Catfish and carp Lentic Systems stagnant bodies of water (lakes) 4 zones Littoral zone Photosynthesis Producers and invertebrates Limnetic zone Light Penetrates, Surface waters Algae and small fish Profundal zone No light, deepest waters Primary consumers (fish) Benthic zone Bottom. Decompose rs