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Author Topic: Another day another virus scare.  (Read 2372 times)

Every Day

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Re: Another day another virus scare.
« Reply #15 on: April 22, 2012, 12:41:27 PM »

Sandman....

Basically the paper states:

Swimming and ion concentrations in the bodies of pink salmon were measured. Small fish taken from rivers were experimentally infected at .34 grams. They only started showing reduced swimming and started having problems when they were this small and had 2 or more sea lice of chalimus 3 or higher. Fish greater than 1.1 grams (pink salmon hit this size less than a week of being in salt water, hence needing to get some from the river), swimming and ion concentrations were not effected by sea lice because they can shed them.

They did two studies in this paper. One experimentally infecting fish and one with wild fish that were already infected. Swimming and body harm was only found to happen under experimental conditions with high levels of female lice that were of a stage of chalimus 3 or higher.  

Now this may not be the same for Atlantic's, to be honest I couldn't find a paper on Atlantic's where this type of sea lice research had been done (makes it hard to believe any one can say it is harming them unless multiple recent studies have been done?).

Now if you go back and read my other posts, and I even believe in the first one you quoted I said that the east coast 9and wherever else Atlantics are native) and the west coast is a completely different story. Places where Atlantic's are native can definitely pose a problem. Same fish carrying the same diseases, both with around the same amount of immunity to disease, and if fish do escape there, they can go out and reproduce which therefore effects the gene pool.

On the west coast... we are using Atlantic's with native pacific's. Atlantic's die much sooner from disease, including many our salmon carry without a problem. Atlantic's have decreased immunity to almost everything so spreading disease to pacific's is highly unlikely (even with all this "ISAv" found, does any one even have confirmation it actually affected these fish, or are they just carriers?). Also if Atlantic's escape, well plain and simple they can't reproduce with pacific's and if they somehow spawn in a river and produce offspring, they will most likely die to disease, due once again to not being able to tolerate IHN and other diseases carried by Pacific's.

And yea absolon hit the nail on the head there. The sites are not picked to protect the fish (kind of my bad in the way I explained it I guess). They are chosen due to flushing capabilities and high current areas so that waste doesn't pile up, so that disease is harder to spread and so that the fish have adequate water quality. Fish farmers aren't stupid like many make them out to be, the amount of science in it is ridiculous. I should once again say I am not involved with farms, and that I don't necessarily agree with them, but I have yet to see a valid argument against them which is why I am taking this stand. The day someone proves to me that fish farms ARE the reason baby pinks have sea lice, are the reason that ISAv is present in B.C., or are the reason for any declines of stocks (which are all on the rebound somehow, weird how that works with ocean conditions eh) then I will take another stand.
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absolon

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Re: Another day another virus scare.
« Reply #16 on: April 22, 2012, 01:09:36 PM »

A couple more comments on that summary paper you cited:

You are aware, of course, that the conference was addressing the situation of Atlantic Salmon in Europe, and that when they refer to the reduction in wild stock breeding capacity, they were speaking of the effects of the escaped farm Atlantics on the breeding capacity of wild Atlantics. That isn't an issue here; we don't have wild Atlantics and farmed Atlantics can't interbreed with Pacifics and consequently escapees have no effect on the breadth and health of the wild genetic library. Our own hatchery support of Pacific stocks to supply the commercial and sport fisheries is the closest we come to a comparable effect on the genetic library of our wild stocks.

You are no doubt also aware that the lice problem in that area and addressed in the summary is greatly exacerbated by the presence of the sea louse Gyrodactylus salaris, a parasite introduced to Norwegian waters in the 70s. Lack of previous exposure to that louse meant the Norwegian stocks had no developed capacity to tolerate it and substantial mortality resulted. The current lice problem is still considerably larger than it would be if the wild stocks were only exposed to native lice for which they had developed defense and tolerance mechanisms over millenia. That particular louse, and for that matter, any exotic, introduced louse, does not occur in our waters.

This is not to say that the results of the conference have no value or relevance, just that in order to draw valid conclusions about the specific situation here, one needs to use information specifically developed in and relevant to our particular circumstances.

Just saw your latest response as I went to post so I'll add answers for it:

The fact of the matter is that it is not coincidence. A healthy environment is required for healthy stocks. Consequently, there will never be anything but what you call "coincidence" and if there is never any exception to that rule, it is hardly coincidence.

There is no "might" about less damaging effects from farms and there is substantial issue with the description of farm effects as damaging in the first place. We've recently been through why there isn't going to be unlimited expansion of the farms; your argument on this point was and remains a strawman.

Urban forests have value as reservoirs in an otherwise devastated-by-development forest but we aren't talking about sea farms occupying the few small remaining areas that could serve as such reservoirs for sealife. In any case, farms are not sited en masse or in areas where the rest of the sea bed has been devastated; they are distributed over a very broad area. Your analogy isn't applicable; don't lose sight of the meaning of what I said in a technical defense of your argument.

While it might be technically possible to have a single point of deposition from all the farms that might be located in one inlet in spite of the mechanisms explained by oceanography, the probability is so low as to be insignificant. Farms learned long ago that locations such as the Sechelt Inlet where such situations might even enter the realm of possibility are bad sites for growing fish. The secondary effects your citation discusses must be also looked at in terms of the site flow rates, the volume of loading and the dilution factor.

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Sandman

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Re: Another day another virus scare.
« Reply #17 on: April 22, 2012, 01:56:15 PM »

We've recently been through why there isn't going to be unlimited expansion of the farms; your argument on this point was and remains a strawman.

In light of K. Dun Gifford's article "Reaching for Solutions: The Water Farming Initiative" in the document I cited above, where he argues that the "short answer to the question "Why Water Farming?" is that a strong expansion of foods grown in water is the realistic solution to many of the current and projected future difficulties we face in feeding the world's peoples with nutritious foods that are grown sustainably and are available at affordable prices,"  I think that expansion of open net salmon farming in BC is inevitable given your insistance there is nothing wrong with the practice in the first place.  Therefore, it is not a strawman. It is the inevitable extension of your own arguments.

Urban forests have value as reservoirs in an otherwise devastated-by-development forest but we aren't talking about sea farms occupying the few small remaining areas that could serve as such reservoirs for sealife. In any case, farms are not sited en masse or in areas where the rest of the sea bed has been devastated; they are distributed over a very broad area. Your analogy isn't applicable; don't lose sight of the meaning of what I said in a technical defense of your argument.

It is applicable, since I was showing that the use of the absolute size of the affected area (the area of Stanley Park) can have very different meaning depending on what you compare it to (the whole coast, or the immediate area of the farms).


While it might be technically possible to have a single point of deposition from all the farms that might be located in one inlet in spite of the mechanisms explained by oceanography, the probability is so low as to be insignificant. Farms learned long ago that locations such as the Sechelt Inlet where such situations might even enter the realm of possibility are bad sites for growing fish. The secondary effects your citation discusses must be also looked at in terms of the site flow rates, the volume of loading and the dilution factor.

Again this appears to be the one point we can agree to disagree on... what constitutes "insignificant" or "acceptable".  This is the one thing that will prove to be the hinge upon which all partner groups will have to come to agreement on to determine the future of aquaculture.  I do think there is a point where we can meet, we just have not found it yet.
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Dave

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Re: Another day another virus scare.
« Reply #18 on: April 22, 2012, 02:15:22 PM »

I do think there is a point where we can meet, we just have not found it yet.

But with informed disussions like this we seem to be getting closer ;)
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aquapaloosa

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Re: Another day another virus scare.
« Reply #19 on: April 22, 2012, 06:32:59 PM »



The above chart indicates the location of the farm leases of which not all are active.  One of those dots fits into burard inlet.  Stanly park is less than one tenth of the area of the inlet it is on.  In my opinion I feel that these charts should not be used to describe the area occupied by a salmon farm.  I do realize that the dots do have to be visible to the eye but it is often displayed in a misleading manor.  To clarify, if all(100 aprox) farms on our coast fit in stanly park, and one of those dots is 10 time larger than the park, then one dot represents 1000 times  the area of one salmon farm.    I urge those who are curious to get on google earth and take a look around and see the actual size of the farms.

Has anyone here done this?

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Sandman

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Re: Another day another virus scare.
« Reply #20 on: April 22, 2012, 08:36:03 PM »



The above chart indicates the location of the farm leases of which not all are active.  One of those dots fits into burard inlet.  Stanly park is less than one tenth of the area of the inlet it is on.  In my opinion I feel that these charts should not be used to describe the area occupied by a salmon farm.  I do realize that the dots do have to be visible to the eye but it is often displayed in a misleading manor.  To clarify, if all(100 aprox) farms on our coast fit in stanly park, and one of those dots is 10 time larger than the park, then one dot represents 1000 times  the area of one salmon farm.    I urge those who are curious to get on google earth and take a look around and see the actual size of the farms.

Has anyone here done this?


Yes, I did.  But back to that later.  First, are you suggesting that the area affected by the salmon farm is less than or equal to the surface area of the net cages?  Do you have any evidence to back that up?  I would suspect that the area affected, due to currents (especially in the "high" flushing sites you say they all use), would be much larger in area than the surface area of the cages themselves.  Even in relatively still water, the area would be larger for all but the largest of particulate matter.  I would suspect that the affected area would be an order of magnitude larger.

Here is an image from Google Earth of one area of the south coast and an image of Stanley Park at about the same scale (you will note that the "eye altitude" of the Stanley Park image is actually slightly lower, despite my simply scrolling over to the Park from the Johnstone Straits, so the park as pictured here is actually shown a little larger than it should be, but it still illustrates my point).

 I have circled the salmon farms and I would argue that the size of the circle is a pretty conservative estimate of the area directly affect by the primary impacts of nutrient loading from farm wastes (feed and feces), whereas the area affected by the secondary impacts and by liquid wastes would be larger (again, we can agree to disagree that these impacts are insignificant and acceptable).

In the lower part of the image you have five farms in an area the size of Burrard Inlet (it would be the same as having 5 farms encircling Stanley Park), and then you have 4 more in the inlet to the North (like 4 more in Howe Sound).  Even if you look at the size of the cages themselves, those 9 farms would appear to cover a "significant" portion of Stanley Park.
« Last Edit: April 22, 2012, 09:06:46 PM by Sandman »
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chris gadsden

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Re: Another day another virus scare.
« Reply #21 on: April 22, 2012, 09:03:47 PM »

Yes, I did.  But back to that later.  First, are you suggesting that the area affected by the salmon farm is less than or equal to the surface area of the net cages?  Do you have any evidence to back that up?  I would suspect that the area affected, due to currents (especially in the "high" flushing sites you say they all use), would be much larger in area than the surface area of the cages themselves.  Even in relatively still water, the area would be larger for all but the largest of particulate matter.  I would suspect that the affected area would be an order of magnitude larger.

Here is an image from Google Earth of one area of the south coast and an image of Stanley Park at about the same scale (you will note that the "eye altitude" of the Stanley Park image is actually slightly lower, despite my simply scrolling over to the Park from the Johnstone Straits, so the park as pictured here is actually shown a little larger than it should be, but it still illustrates my point).

 I have circled the salmon farms and I would argue that the size of the circle is a pretty conservative estimate of the area directly affect by the primary impacts of nutrient loading from farm wastes (feed and feces), whereas the area affected by the secondary impacts and by liquid wastes would be larger (again, we can agree to disagree that these impacts are insignificant and acceptable).

In the lower part of the image you have five farms in an area the size of Burrard Inlet (it would be the same as having 5 farms encircling Stanley Park), and then you have 4 more in the inlet to the North (like 4 more in Howe Sound).
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absolon

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Re: Another day another virus scare.
« Reply #22 on: April 22, 2012, 09:31:46 PM »

Yes, I did.  But back to that later.  First, are you suggesting that the area affected by the salmon farm is less than or equal to the surface area of the net cages?  Do you have any evidence to back that up?  I would suspect that the area affected, due to currents (especially in the "high" flushing sites you say they all use), would be much larger in area than the surface area of the cages themselves.  Even in relatively still water, the area would be larger for all but the largest of particulate matter.  I would suspect that the affected area would be an order of magnitude larger.

Here is an image from Google Earth of one area of the south coast and an image of Stanley Park at about the same scale (you will note that the "eye altitude" of the Stanley Park image is actually slightly lower, despite my simply scrolling over to the Park from the Johnstone Straits, so the park as pictured here is actually shown a little larger than it should be, but it still illustrates my point).

 I have circled the salmon farms and I would argue that the size of the circle is a pretty conservative estimate of the area directly affect by the primary impacts of nutrient loading from farm wastes (feed and feces), whereas the area affected by the secondary impacts and by liquid wastes would be larger (again, we can agree to disagree that these impacts are insignificant and acceptable).

In the lower part of the image you have five farms in an area the size of Burrard Inlet (it would be the same as having 5 farms encircling Stanley Park), and then you have 4 more in the inlet to the North (like 4 more in Howe Sound).  Even if you look at the size of the cages themselves, those 9 farms would appear to cover a "significant" portion of Stanley Park.

You appear to have lost track of the original point regarding Stanley Park. The original point was that the total area occupied by farms was about the size of Stanley Park: every farm could fit into an area that size and a comparison of that area to the total area of coastal BC waters is therefore representative of what proportion of the total sea bottom on the BC coast is under farms. Since several Stanley Parks could fit into Burrard Inlet, it is clearly apparent that at least twice as many farms as exist could fit in Burrard Inlet. With respect to the original point, no technical manipulation of the argument or manufacturing of new, self determined parameters and definitions will change that.

You have yet to demonstrate the nature of any harm that might arise from any deposition that does occur or, more critically, even that harm occurs.



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aquapaloosa

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Re: Another day another virus scare.
« Reply #23 on: April 22, 2012, 09:34:37 PM »

Quote
Yes, I did.  But back to that later.  First, are you suggesting that the area affected by the salmon farm is less than or equal to the surface area of the net cages?  

  No,  I am not discussing the "debated effects", I will leave that to the others and it has been discussed extensively and I have not seen any presented.  My point is to make clear the actual size of the farm site cages.  

Will someone, anyone please answer my question.  For the third time:

The fact is that some of the supporters here are accomplished fish biologists that have worked in other (salmon)fields entirely and for many years.  Those individuals seem to bring the most to this forum when it comes to information about salmon management.  So why would they support salmon farming in BC?  Why?  

Paper covers rock with the response " ya but there is an effect"  but what is important is the measurement of the effect.  What is rarely discussed is how the environment benefits from an active salmon farm.

By the way SM, I am generally aware of the others backgrounds in this debate.  Whats yours?  You know me.  I'm a  salmon farmer.


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Sandman

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Re: Another day another virus scare.
« Reply #24 on: April 22, 2012, 09:42:50 PM »

 
By the way SM, I am generally aware of the others backgrounds in this debate.  Whats yours?  You know me.  I'm a  salmon farmer.


I believe I mentioned it before when you (or someone else) asked, I am an environmental historian.
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aquapaloosa

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Re: Another day another virus scare.
« Reply #25 on: April 22, 2012, 09:55:37 PM »



My bad. I do recall that now.  Interesting.  How does one make a living as a environmental historian?  Just curious.  PM me if you wish, or not.  Either way thanks for that. 
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Sandman

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Re: Another day another virus scare.
« Reply #26 on: April 22, 2012, 11:13:06 PM »

You appear to have lost track of the original point regarding Stanley Park. The original point was that the total area occupied by farms was about the size of Stanley Park: every farm could fit into an area that size and a comparison of that area to the total area of coastal BC waters is therefore representative of what proportion of the total sea bottom on the BC coast is under farms.

No, I have not lost track. You said that all 100 farms would cover an area the size of Stanley Park, and I said that these 9 farms alone appear to cover a signifcant portion of Stanley Park (cover the image with clear plastic and shade the farms in with a fine tip felt pen (just the cages if you like), and then place the shaded area over the image of Stanley Park (which is already slightly larger than it should be) and you can see that these 9 farms cover about 1/3 of the park.  I am no mathematician, but 100 farms would appear to cover 10 times more than 9.   Now, even if you do not accept that the area directly affected by the nutrient loading is larger than the surface area of the farms, (therefore, the area affected by these 9 farms is already larger than the area of Stanley Park), you can see that the farms already cover a larger area than Stanley Park.  Furthermore, I have said that comparing the area to the farms to the total area of the coast is also not as useful as comparing the size of the farms to the amount of sea floor in the immediate area (the farms around Senora Island cover an area 1/3 the size of Stanley Park).

You have yet to demonstrate the nature of any harm that might arise from any deposition that does occur or, more critically, even that harm occurs.

Sorry, I thought I had.

"Previous studies have demonstrated that the most evident consequences of fish farming on the benthic environment are an increase in total organic carbon (C) accumulation in the sediment and a decrease in oxygen availability for the benthos beneath fish cages (Holmer 1991, Holmer and Kristensen 1992, Karakassis et al. 1998). These changes, in turn, have significant impact on the abundance and biodiversity of micro-, meio- and macrobenthic organisms (Karakassis et al. 2000, Mirto et al. 2002, La Rosa et al. 2004). Other recent studies have demonstrated that fish-farming effluents have effects also on the biochemical composition of the organic matter of sediment. Fishfarm sediments are sometimes enriched in lipid content due to the accumulation of uneaten fish-food pellets on the seafloor (Mirto et al. 2002, Bongiorni et al. 2005), and are characterized by increased microbenthic algal biomass in response to the increased availability of nutrients below the cages (La Rosa et al. 2001)." (Pusceddu et al, "EFFECTS OF INTENSIVE MARICULTURE ON SEDIMENT BIOCHEMISTRY,"  Ecological Applications, 17(5), 2007, p. 1367)  

In their study in the Mediterranean, Pusceddu et al. also found that "intensive aquaculture can significantly contribute to benthic eutrophication processes, although the extent of the spatial effects of fish-farm effluent is potentially limited. However, even though spatially limited, the impact of the biodeposition derived from fish farms is site specific and can be driven by both physico-chemical and trophic contexts. We have also been able to empirically derive the minimum distance at which the siting of new fish farms should be permitted in the presence of benthic systems traditionally considered vulnerable. To date, since background ecological features on a local scale appear to have the major role in affecting the patterns of fish-farm-induced eutrophication, the future siting of fish farms should include well-designed a priori monitoring programs that are able to describe the whole ecological setting and should be tailored to the basis of the local ecological context." (Pusceddu et al, p. 1376)  

While they agree with you that current velocity has an effect of lowering the "fish-farm-induced benthic eutrophication" but, they also recognize in turn, that "the spatial extent of the potential impact will be spread farther from the cages than in those sites with lower bottom currents." (Pusceddu et al, p. 1372).

Closer to home:

"Waste from finfish netpens and cages flows directly into marine waters and, in contrast to terrestrial farms, there is usually no attempt to capture it. Nutrients and suspended solids discharged by salmon farms can have considerable effects on a local scale (Goldburg et al. 2001), although salmon farms sited in well flushed areas often have minimal impact on the quality of surrounding waters (Brooks and Mahnken 2003). Dilution of nutrients means that widely spaced marine fish farms sited in areas with strong currents will probably have little impact, an argument for moving marine aquaculture out of coastal waters and into the open ocean (Marine Research Specialists 2003). . . Producing a kilogram of salmon releases approximately 0.02 to 0.03 kg of N [the nutrient primarily responsible for eutrophication in marine waters], excluding losses from uneaten feed (Brooks and Mahnken 2003). About 70 000 mt of salmon were produced in British Columbia in 2003 (C Matthews pers comm) with a gross domestic product value of C$91 million, or approximately US$66 million (Marshall 2003). Thus the BC salmon farming industry discharged about 1435 mt to 2100 mt of nitrogen" or the equivalent of 200 000 hogs. (Goldburg and Naylor, "Future seascapes, fishing, and fish farming," Front Ecol Environ 2005; 3(1): 2128

You may argue that the eutrophication of the seafloor beneath the farms is "insignificant" compared to the total size of the coastal sea floor, or that this harmful effect is minimized under the farms by site flushing; however, I think "the nature of any harm that might arise from any deposition that does occur" has been demonstrated.
« Last Edit: April 22, 2012, 11:32:21 PM by Sandman »
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Sandman

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Re: Another day another virus scare.
« Reply #27 on: April 22, 2012, 11:28:16 PM »


My bad. I do recall that now.  Interesting.  How does one make a living as a environmental historian?  Just curious.  PM me if you wish, or not.  Either way thanks for that. 

I did not say I make a living doing history, I said that is my background, I make a living as a teacher.
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absolon

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Re: Another day another virus scare.
« Reply #28 on: April 22, 2012, 11:49:24 PM »

You are pointing out potential effects, not harm. To be meaningful, you need to demonstrate the the effects cause harm by some more rigorous manner than expressing your personal opinion.

Further, the numbers you quote as "evidence" are meaningless in the absence of a comparative standard by which they can be evaluated. For instance, an area 10 km by 10 km by 100m deep contains 10,000,000,000 tonnes of water and if all that 2000 tonnes of Nitrogen produced by one years crop of salmon were dissolved in that area, a concentration of 1 part nitrogen in 5,000,000 parts seawater would result if there were no consumption of that nitrogen by plants and algae which are actually food for higher forms of life which are themselves in turn consumed by even higher forms of life. Since the volume and therefore the weight of water in the coastal areas of BC is orders of magnitude greater than the calculated example, since it is constantly mixed by winds, waves and tide and since dilution rate is logarithmic over distance in three dimensions, the actual concentration of Nitrogen will be orders of magnitude less than 1 in 5,000,000 and the cumulative effect all but unmeasurable. Were it measurable, it would likely display an ever-so-slight increase in the standing biomass of life in coastal waters

I suspect that if you had ever been anywhere near a salmon farm you would realize how ridiculous your notion that 9 or a dozen farms would fill the Park is. Even if they did, ten times the size of the Park is still a minuscule area compared to the extent of the coastal waters of the province and it wouldn't change Nitrogen production.
« Last Edit: April 23, 2012, 12:04:49 AM by absolon »
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chris gadsden

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Re: Another day another virus scare.
« Reply #29 on: April 23, 2012, 05:36:16 AM »

I did not say I make a living doing history, I said that is my background, I make a living as a teacher.
  Good on you for posting your  background and profession. It would be appreciated if others on this debate would do the same, absolonn, aquapaloos, shuswapsteve, Dave etc.. Are you up to that? ;D ;D

 Of course I have been retired for 14 years and worked in highway engineering for 35 years  for the Provincial Government.

PS
I believe one of you may have once before but it would be good to state it again.