I'm sorry I don't quite understand your question about the sea water rising?
There was a great article in "the monthly" written by Claire Konkes, where she goes into the legal action that Huon is taking against the government regarding Macquarie Harbour and the biomass cap. Its worth a read although you need to be a subscriber to read it all. Ill post the link at the bottom.
The point I was making was that when there was a cap of around 9000t all three farms successfully farmed the harbour for years with little to no issues with oxygen. Then the cap was raised and more and more fish went into the water. With each extra fish that was put in it takes more of the oxygen that is in that water, that's fine in an area that constantly gets replenished by new oxygenated water but in the harbour there is only a very small inlet.
Think of it as being in a small room by yourself, lots of air in there and no problems. Then cram 10 or 20 people in that room and it soon becomes stuffy and crowded. If you don't either, let more air in or let people out you all get carbon monoxide poisoning. Same with the Harbour. Except the fish will just die.
Now the cap is at 14000t which is still a lot higher then when things were good.
I am of the opinion that why wouldn't you bring the cap back to where it was when there was no problems. Why keep it high and why allow even more fish to be in there coming into summer when that is the worst time for oxygen? to me it just doesn't make sense, and honestly its worrying that its allowed to happen. Money is great and makes the world go round but thats no use to people who cant make any because they have no jobs or industry in their town anymore.
Could you please explain this line for me?
"More fishes do not mean there're lesser oxygen as the Biomass is used to purify the water. the cleaner the water the healthier the fish." This is incorrect.