The latest report card on Great Barrier Reef water quality has shown signs of improvement, but the health of the marine environment near to the shore is still poor due to pollution runoff from the land.

The good news is that pollution levels in reef waters have declined in the last five years, and it appears that most pollutants are tracking towards the pollution reduction targets planned for 2018.

For example, the level of phosphorus in reef waters has dropped by 14.5%, and has suggested that the aimed 20% decrease in phosphorus loads by 2018 can be achieved. Pesticide and sediment loads have dropped about half, tracking towards the 60% decrease goal for pesticides, and a more modest target of 20% reduction of sediment load by 2018.

But, the sad news is that the loads of dissolved inorganic nitrogen were dropped by just 17%, and it seems that the 50% reduction target is hard to achieve by 2018. Nitrogen loads have recorded roughly six times higher as compared to natural background levels.

Every year, about 80,000 tones of pollutant nitrogen gets into the Great Barrier Reef lagoon. The Burdekin, Wet Tropics and Mackay-Whitsunday regions add more than 78% to the modeled dissolved inorganic nitrogen load mainly from agriculture.

Thus, improvement in nitrogen management is still a main concern for the banana industry in the Wet Tropics, and the sugarcane industry in all production regions where rivers flow into the Great Barrier Reef.

Discharge of Nitrogen is considered a major water quality risk as it increases the presence of phytoplankton (algal blooms) which is linked to outbreaks of crown-of-thorns starfish.