Backyard Aquaponics
A place to discuss aquaponics

news item tonight that excessive levels of mercury found in fresh water bass in the Hinze dam (Gold Coast), other dams to be checked

maybe i shouldn't have broken my thermometer..................

Ell,
Yes, I saw that bit. If the fish have high levels of mercury, then they must either be getting it from their food source or it's in the water. Glad I'm not drinking that water - yet. Gov't working on connecting the Hinze dam to the water grid.

Fortunately the weather goes in about 33 year cycles, so we are heading towards more wet weather in the coming few years.

cool! Jonty got anything else on the water cycles?

Jump to this site and have a look. This guy seems to be on the ball predicting weather. http://www.predictweather.com/

I can't seem to find much on mercury levels of our fish. I've seen some post which say AP fish have NO mercury...which can't be right as I understand it, all aqua-life have some level of mercury

I have alot of questions on this matter, can we reduce the amount of mercury in our fish?

Mercury in fish ... is a cumulative uptake from either feed or polluted water....

In AP (and freshwater aquaculture) mecury in the feed isn't an issue... and source water should be OK as well....

If you're drawing your water from a well or bore ... then you should probably have it tested beforehand...

If it's got nasties in it... then you shouldn't probably use it for even your dirt garden... or AP... let alone drink it....

In those cases, you'd either have to find another source of water... or install an RO system...

It is POSSIBLE that the breeders having lived long and fruitful lives, might have an accumulation of mercury, but there would not be much of that passed though to eggs, so mercury in AP fish would be exceedingly low.

Mercury is predominantly a problem in larger predatory fish. All fish in rivers and sea pick up mercury from the pollutants in the water or feed.
Usually this is not enough to harm them or you.
BUT fish that eat other fish, 'Double up' with every feeding. So because they eat other fish, their intake is from the water, AND feed.
The bigger the fish, the bigger the accumulated mercury uptake.
So whilst Omega3 is very good for pregnancy, eating heaps of big fish (as some1 did who was on TV last year) will also dose you with a heap of mercury (smaller fish, the percentage is lower)
Mercury whilst bad for you, is detrimental to pregnancy, and can cause miscarriages.
And I think I've gone way OT with this ramble...

Nar Kuda this is as on-topic as you get...

Yeah I was going to bread pacific blue eyes to feed to the SP (if they will eat them) or GP but worried about the mercury level.

SP tend not to eat life fish. GP will though. eat each other

There was a period of time several years (or more) back where people were trying to eat as much fish as they could for the healthy benefits of it. Unfortunately, it was popular to eat things like tuna, sword fish, shark, and other big game fish etc, which are all pretty high up the food chain and hence have more mercury build up. When you have mothers and young children eating this stuff on a daily basis, there can be some bad side effects. Bad for pregnancy, can cause birth defects, fatigue, headaches, hair loss, memory problems, etc. So, then came the recommendations of women who are pregnant or might become pregnant should limit their intake of such fish to once or twice a week tops. I think those recommendations have been relaxed a bit lately though.

Anyway, finding high levels in fresh water fish is a little disturbing. Is that damn fed by water that comes from a mining area where mercury is a pollutant?

Ahh yes I forgot the mental problems... Mercury used to be used in hat making. Hence the term "Mad as a Hatter"
It truly is evil stuff. Most heavy metals are. Lead and Mercury we're exposed to more than any other though, Well besides gold and stuff, but that's hard to get into your body.

Yep evil gear
Here is some reading on the subject though not Aussie based, it highlights the need for better control measures.
http://www.nrdc.org/health/effects/mercury/sources.asp

Cheers
VM

there is a little used saying that goes something like,

small fish for small people big fish for big people.

Children suffer more from mercury poisoning than adults so they should only eat small fish which have less mercury in them

Back in my younger days (Late 60's-early 70's,) I recall seeing TV documentary regarding Mercury.

There was a museum somewhere in England that had only recently (Back then) stopped letting people walk across a vat of the stuff as part of a tour.


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