Re: "We have created life out there," Oct. 16.
The article on the Haida Gwaii's dumping of 100 tonnes of iron sulphate into the ocean fails to address the primary purpose of this experiment as far as fish habitat is concerned.
While I agree that the procedure was scientifically hasty and controversial, the purpose of enhancing salmon returns by increasing plankton production has considerable justification.
There are many published scientific papers showing a positive correlation between phytoplankton abundance and fish production.
In the 1960s, I organized and started a nutrient enrichment program on Great Central Lake, which resulted in a sevenfold increase in sockeye salmon returns to the lake, continuing for many years.
Andrew Weaver states there is no proof that plankton blooms initiated by fertilization has an effect on salmon production, but that is not true. In the Gulf of Alaska, volcanic emissions in 1958 and 2008 both resulted in enormous sockeye salmon returns; in the latter year, this was attributable to a bloom of diatoms, caused by iron from a volcano.
Diatoms are the clover of the sea, in that most of the world's largest fisheries in upwelled areas are based on food chains initiated by diatom growth. However, in the Gulf of Alaska, iron, which is an essential nutrient for diatom growth, is generally lacking.
Thus the logic behind the Haida Gwaii's experiment, as far as it concerns enhanced sockeye salmon production, is justifiable. Their timing and positioning of the iron dumping was meant to coincide with the migration of young fish into the ocean. Whether they achieved this precise timing and location will not be known for two years, when the 2012 adults return.
Further, from the initial ocean monitoring, ecological damage does not appear to have occurred.
Tim Parsons, professor emeritus, Earth and Ocean Sciences University of British Columbia
Brentwood Bay
