Sources of nutrients:

• Nutrients enter wetlands from diffuse catchment via overland local surface flow, in floodwaters (overbank flow) or groundwater or directly from urban and agricultural land use or point sources.
• Nutrients can be dissolved in the water or bound to sediments.
• Plants and algae can act as nutrient sinks as they remove nutrients from the water column/groundwater.
• Nitrogen from Sewage Treatment Plants (STP) has an increased delta¹⁵ N signature which can be traced through the food chain.
• Nutrients are cycled naturally within the system with nitrogen (N² gas) lost through denitrification.
• Clearing of wetland, fringing zone or catchment vegetation, or vegetation loss through poor fire management, can result in increased run-off due to bare ground or decreased nutrient removal from the incoming waters.
• Agricultural activities can increase nutrient loads through fertiliser run-off or erosion (nutrients bound to sediments).
• Dense fauna populations (e.g. bird colonies, feral pigs) and livestock can increase nutrient loads directly to wetlands through faeces and urine.
• Numerous land-use activities, such as feedlots, N-fixing crops, golf courses, aquaculture, mining, forestry, housing (septic tank leakage), can be sources of nutrients to wetland.