Originally Posted by thomas
I can't be an environmentalist, I drive a 4x4 and a RIB when I could be a raggie with a Golf although I do have a heat pump.
Since posting I did some research and found copper antifoul is more friendly, but my mate was told it would kill the fish and copper's not used anymore, something's different these days as it used to be shunned upon so was wondering how it;s different as it clearly has changes.
Yeah! Not easy being a RIBnetter and an environmentalist.
I just wonder if your pal was ill informed. Copper has indeed been used for hundreds of years as antifouling. In the 1960's or 70's a new, more effective antifouling paint was introduced, based on organo tin compunds. TBT (Tri Butyl Tin - I think). This was also far less reactive when applied to steel boats and ships (copper makes them rust) and a great success.
The paint manufacturers had test sites around the coast where samples were tested for effectiveness in differing conditions. AFAIK, one of these sites was a mussel/oyster farming area. The shellfish started to die off (I think because the TBT made one gender change sex.) .
Eventually TBT was banned for use on small boats because they spend much time moored in shallow shellfish areas. It was still allowed on big ships, fishing boats etc. Ironically, salmon farmers were allowed to dip their net cages in highly concentrated TBT until quite recently.
The only alternative was to revert to paints containing copper compounds. I think the idea of the 'ablading' or 'self polishing' paints now is that they don't flake off at the mooring or in the marina, thus creating a high concentration of toxins in a small area, but are worn away gradually (to expose fresh layers and keep the bottom clean) while under way, spreading the copper over a large volume of water where it will be below toxic levels.
Copper and its salts are 'natural'. There will be millions of tons of it dissolved in the worlds oceans. Obviously, fish cope with it.
Of the antifouling methods available, I think Coppercoat, or similar, is probably the best and most environmentally friendly. I suspect very little leaches out into the surrounding water and it only kils things that try to attach themselves to the hull.
I just wish I could afford it.
PS I am not an 'expert', or a chemist or toxicologist, so the above may not be 100% accurate. It's just what I've learned over forty years of professional and semi professional seafaring.
Ah. I see Ewan got there first. Must type more quickly.