As has been pointed out to you, drug and chemical treatments occur very infrequently and involve very small quantities.
Yet, still you provide no evidence of this. However, a study done in 1997 of antibacterial usage found use varied considerably among farms with some farms using as much as 450kg active ingredient per year with "moderate" usage around 70 - 170kg annual usage (Herwig et al 1997), and these farms there it was found that 20% of the bacteria in the sediments near the farm were anti-bacterial resistant.
Because of modern feeding technology, another innovation by the industry to reduce it's environmental effect, very little feed escapes the pen. What does escape can be consumed, but is more likely to settle into bottom sediment where it will decompose. The total affected area under pens amounts to several hundred acres on a coastline that consists of hundreds of thousands acres or more. The impact is extremely small.
Yet still you provide no evidence of this. In the document you provide later as evidence that the environmental effects are minimal (Dr. Weston's 1985 paper) doesn't even deal with fin fish waste as it is on floating shellfish farms (I am no biologist, but I suspect shellfish produce less waste than fin fish). Now Weston's 1990 study may be more useful as he does document the effects of fin fish farms in Puget Sound on the macrobenthic community and there he confirmed that the effects were indeed profound:
With increasing proximity to the farm there was: (1) reduced areal species richness; (2) reduced macrofaunal biomass; (3) an order-of-magnitude increase in Capitella cf. capitata density; and (4) a slight decrease in total macrofaunal abundance. (Weston 1990)
Weston also reported that "All chemical measurements indicated that the 0 m station [the one directly below the site] was heavily affected by culture activities....[and that the] effects of culture activities on the seafloor were readily visible." Of course his study was only of the "enrichment" effects of the farms so his chemical analysis was limited to carbon, nitrogen, water-soluable sulphide content (caused by the de-oxygenation of the sediments), and mineral stability. He was not testing for the presence of other chemicals associated with the feed like the antibiotics and pesticides so his study is not useful to showing these impacts are "miniscule".
It was studies like this, and the reaction by those "reactionists" that saw fish farms move to new sites that were better flushed (Rensel and Forster 2007). However, moving to a better flushed site does not reduce the
effects of "enrichment," it just reduces the enrichment (the site continues to produce the harmful outputs, but they are better distributed to reduce the effects, kind of like running a car in a closed garage vs opening the bay door or piping the exhaust outside...the exhaust is just as harmful, but it is now being released into the outside air and being "diluted" so the effects are no longer seen). Even in their report "Beneficial Environmental Effects of Marine Finfish Mariculture" (from which I see you get most of your arguments) prepared for the NOAA National Marine Fisheries Service's National Sea Grant College Programme, Rensel and Forster admit that there were "adverse effects" at some earlier sites that were studied in the 1990s (they also cite Weston), but that "most of the problems associated with net pen aquaculture in the U.S. are manageable or have been dealt with" so we need not worry any more as the fish farms are now "properly located."
Furthermore, your argument that these farms are affecting a small percent of the coastal area is negated by the desired expansion of the industry. The more the industry expands the greater this impact will be. But of course it can expand unchecked until some one else provides the inarguable proof of the concentration numbers that would make the impact "harmful." And who gets to decide which small parts of the environment get to be written off while the farms are there?
Document those catches of second generation young. I know you and your compatriot reactionaries don't do proof, but I'd like to see some.
I thought "The world doesn't owe you the answers; you've got the responsibility for the matter." Again the "H" word comes to mind...but here it is anyway.
http://www.google.ca/url?sa=t&rct=j&q=juvenile%20atlantic%20salmon%20british%20columbia%20tsi&source=web&cd=1&sqi=2&ved=0CCIQFjAA&url=http%3A%2F%2Fweb.uvic.ca%2F~serg%2Fpapers%2FVolpe%2520et%2520al.%25202000%2520Conservation%2520Biology%2520(14)%2520899-903.pdf&ei=RQkRT6v6LOSniQKThZjLDQ&usg=AFQjCNFdAHkCm1j9cTHcCAZPjWpa563fUA&sig2=IoRe4ddfyQ8PsZUo_JXAIg&cad=rjaThe introduction was reasoned and well managed, the introduced stock is contained and controlled.
The escapes have been reduced but not eliminated (just the reporting has). A review of the research has revealed that open net salmon farms contribute to coastal nutrient pollution (exacerbating existing problems from agricultural runoff, sewage discharges and atmospheric deposition), releases toxic compounds (exacerbating existing pollution of coastal ecosystems), and interferes with the performance of existing wild salmonid stocks (exacerbating the continuing decline in wild salmon stocks). Given the large gaps in our knowledge and the acknowledged poor state of health of wild stocks, regulatory agencies and policy-makers should apply the precautionary principle to decisions concerning expansion of salmon aquaculture in BC waters.
Victoria dumped it's sewage and it was essentially harmless because of the principle of dilution. The greenies got up in arms because it violates environmental principles not to be seen to treat it so it didn't matter if Victoria's sewage discharge actually caused no harm, it became a bone in their craw. The conjured images of turds bobbing around the kelp beds made it great subject for the media, guaranteed to raise hackles and arouse public ire. Never mind that it actually doing no harm at the levels of discharge that were done.
Well there you have it. So intent are you to defend the farms you are actually arguing that Victoria pump raw sewage into the Straits.
Dilution does not get rid of what’s in sewage (organics, pathogens like hepatitis, heavy metals or chemicals) and therefore it doesn’t prevent the long-term damage to the environment, or the waste of the energy and mineral resources carried by sewage. Furthermore, contrary to what we’ve been told, the currents near the outfalls do not carry the sewage out into the Pacific. Rather, because currents change direction with the ebb and flow of the tide, a lot of the sewage either stays nearby or flows back into Georgia Strait. And I am not picking on Victoria, as most of Greater Vancouver sewage only receives primary treatment and then frequent discharges of untreated sewage occur after heavy rains back up the sewer systems. Not to mention that non-point source pollution is just as damaging as it too is untreated. But as I have already stated, just because there are other harmful effects caused by other activities, that does not mean we should not continue to work to eliminate them. Open pen fish farms, as a source of pollution, just do not need to be here ,so unlike stopping oil run off from road after a rainfall, harm from a fish farm can easily be removed by their closure.
I'll tell you what; it's time to broaden your horizons a bit. I'll give you a little lesson on confirming facts for yourself. Go to Google and type in the search box "metabolization of antibiotics" and start reading. Follow the useful links and start compiling the information you need to consider in order to answer your question. The world doesn't owe you the answers; you've got the responsibility for the matter.
Stop patronizing anyone who does not restrict their reading to Aquaculture Digest as "narrow minded" and practice what you preach. I have read the literature, many of the same sources you cite, and I just do not agree with the conclusions that you, and the aquaculturalists, are drawing from them.