A few papers on Diatoms and Fish
The Dependence of the Fishes on the Diatoms
Ecology, Vol. 2, No. 2 (Apr., 1921), pp. 79-83
Stable URL: http://www.jstor.org/stable/1928919
“No diatoms, no hake”
"There is no better illustration in science of the practical value of ecology than is afforded by the diatoms. The economic importance they are now  seen to have might have been understood fifty years earlier [i.e, 1871] and some use might have been made of their value during that period of time, if the inter-relation of these remarkable plants with other forms of aquatic life had been prominent in the minds of investigators. As it is, they remained for many years little more than the playthings of microscopists, prized and wondered over because of their astonishing beauty, collected at great expense by enthusiastic amateurs, and illustrated in costly books, which may be searched through in vain for any hint of their worth outside of that belonging to their symmetry of form and striking loveliness of design."
[ for the past 90 / 140 years Diatoms have been badly neglected, we are trying to remedy the situation.]
A rising tide lifts all phytoplankton: Growth response of other phytoplankton taxa in diatom-dominated blooms.
R. T. Barber and M. R. Hiscock
"4. Diatom Response
It has commanded much attention because of the well-established relationship between diatom blooms and fish production [Iverson, 1990], which led Bostwick Ketchum to revise Isaiah 40:6 this way,
‘‘All fish is diatom.’’
[Isaiah 40:6 - A voice says, "Cry out." And I said, "What shall I cry?"
"All men are like grass, and all their glory is like the flowers of the field.]
Flood of ‘08 served up feast for fish
“Compared to other phytoplankton, diatoms are like juicy steaks,” said Aguilar, who has been studying Lake Michigan’s diatoms and other phytoplankton for over a decade.
One may almost say no diatoms , no oysters. Some curious observations have been made in this respect. Mr. Bartholomew reports that the Menhaden (a surface feeding fish of the herring family) is quite a consumer of diatoms. He writes as follows: "You will probably be astonished to know that a 200 millimeter beaker of Menhaden intestines will frequently yield, after cleaning 25 millimeter of diatoms. Years ago, I thought I was a collector but my hat is off to the Menhaden."
Sardines above 100 mm. feed primarily on diatoms, though copepods are at times prevalent. Among the adult sardines of 200 mm. or longer the food is mainly diatoms, and occasionally dinoflagellates or schizopods occur in major numbers.
Dr Victor Smetacek, he was the Chief Scientific Officer of LOHAFEX, the 13th Iron Fertilization experiment conducted in 2009
Diatoms - Krill - Whales; "the food chain of the giants."