Methodology
I noticed a new instrument on display, the Iatroscan, and the UK agent
let me have one without the sales commission as he had no agent in
Canada. It came and I was looking forward to doing personal research
with it. After a week I could not get near it as my technicians stopped
scraping silica gel off TLC plates and demanded to use the Iatroscan for
lipid quantification. As we say “the rest is history” and once I moved to
TUNS a Ph.D. candidate C.C. Parrish, came along and did some excellent
work on quantification of dissolved and particulate sea water lipids.
Happily, he now has a good research and teaching appointment at
Memorial University in Newfoundland and is still active with the
Iatroscan in examining the lipids of fish eggs and larvae for aquaculture, and of seston for scallop nutrition. I even sent an Iatroscan to sea
with your neighbour R. Delmas. The TLC-FID equipment worked
fine but the dirty and oily environment was inhospitable. Lately, we
have used a Mark 5 with a nitrogen-sensitive thermionic detector to
separate marine toxins such as the domoic acid that affiicts our shellfish industry. The specific nitrogen sensitivity over the FID mode is at
least 100-fold.
As I am now as near the site of the Amoco Cadiz disaster as I ever expect
to be, I want to mention our work on the uptake of hydrocarbons into
the adipocytes of salmon. One day I had idly asked a student to look
at the white lines in farmed salmon steaks. In wild salmon these were
much less obvious. He found that these were white connective tissue
bands and the location of many adipocytes, cells of pure fat. The wild
fish included some carotenes in these fat deposits, colouring the white
connective tissue and blending with the colour of the pink muscle
pigmented with astaxanthin. The farmed fish did not access these
carotenes in their diets, so the white connective tissue and colourless
adipocytes were more obvious.
This very good student also showed that water-soluble petroleum hydrocarbons (the nasties such as benzene, toluene and xylene in particular)
could be flushed out of the salmon muscle intercellular fluids in a few
days, but once in the adipocytes they persisted for up to 30 days. His
work on the size distribution of the adipocytes was at the same time
mirrored exactly by B. Fauconneau et al. of Inra-Rennes in rainbow
trout muscle. These two studies show how homogeneous world-wide
marine science can be, and it is to be hoped that our present international cooperation on marine lipids will continue.
By a remarkable coincidence, the last twenty years of my research
interests have been based on the same job I started with, promoting
the health benefits of fish oils. Vitamins A and D in cod liver oil are
“natural”, currently a popular phase in “neutraceutical" circles, but it
is probable that two long-chain omega-3 fatty acids EPA (eicosapentaenoic) and DHA (docosahexaenoic) could be of even more benefit to
anybody taking cod liver oil. The Eskimos of Greenland and northern
Canada did not eat much fish. Most of their diet was seal oil and meat
as described by Bang & Dyerberg (1979-1980). Fish oil became the only
alternative available for biomedical research and thousands of papers on
13
I noticed a new instrument on display, the Iatroscan, and the UK agent
let me have one without the sales commission as he had no agent in
Canada. It came and I was looking forward to doing personal research
with it. After a week I could not get near it as my technicians stopped
scraping silica gel off TLC plates and demanded to use the Iatroscan for
lipid quantification. As we say “the rest is history” and once I moved to
TUNS a Ph.D. candidate C.C. Parrish, came along and did some excellent
work on quantification of dissolved and particulate sea water lipids.
Happily, he now has a good research and teaching appointment at
Memorial University in Newfoundland and is still active with the
Iatroscan in examining the lipids of fish eggs and larvae for aquaculture, and of seston for scallop nutrition. I even sent an Iatroscan to sea
with your neighbour R. Delmas. The TLC-FID equipment worked
fine but the dirty and oily environment was inhospitable. Lately, we
have used a Mark 5 with a nitrogen-sensitive thermionic detector to
separate marine toxins such as the domoic acid that affiicts our shellfish industry. The specific nitrogen sensitivity over the FID mode is at
least 100-fold.
As I am now as near the site of the Amoco Cadiz disaster as I ever expect
to be, I want to mention our work on the uptake of hydrocarbons into
the adipocytes of salmon. One day I had idly asked a student to look
at the white lines in farmed salmon steaks. In wild salmon these were
much less obvious. He found that these were white connective tissue
bands and the location of many adipocytes, cells of pure fat. The wild
fish included some carotenes in these fat deposits, colouring the white
connective tissue and blending with the colour of the pink muscle
pigmented with astaxanthin. The farmed fish did not access these
carotenes in their diets, so the white connective tissue and colourless
adipocytes were more obvious.
This very good student also showed that water-soluble petroleum hydrocarbons (the nasties such as benzene, toluene and xylene in particular)
could be flushed out of the salmon muscle intercellular fluids in a few
days, but once in the adipocytes they persisted for up to 30 days. His
work on the size distribution of the adipocytes was at the same time
mirrored exactly by B. Fauconneau et al. of Inra-Rennes in rainbow
trout muscle. These two studies show how homogeneous world-wide
marine science can be, and it is to be hoped that our present international cooperation on marine lipids will continue.
By a remarkable coincidence, the last twenty years of my research
interests have been based on the same job I started with, promoting
the health benefits of fish oils. Vitamins A and D in cod liver oil are
“natural”, currently a popular phase in “neutraceutical" circles, but it
is probable that two long-chain omega-3 fatty acids EPA (eicosapentaenoic) and DHA (docosahexaenoic) could be of even more benefit to
anybody taking cod liver oil. The Eskimos of Greenland and northern
Canada did not eat much fish. Most of their diet was seal oil and meat
as described by Bang & Dyerberg (1979-1980). Fish oil became the only
alternative available for biomedical research and thousands of papers on
13