Mackerel and sunshine.

While the sun continues to bless Mount's Bay with its presence there's some interesting reading for the mackerel boys to be had in a quiet moment while the fish aren't chewing - this comes from a journal published 100 years ago entitled "Mackerel and Sunshine" by E. J. Allen.

In his paper on “Plankton Studies in Eelation to the Western Mackerel Fishery,” in the last number of this Journal (Vol. VIII., p. 269), Bullen shows that for the years 1903–1907 there appears to be a correlation between the number of mackerel taken during May and the amount of Copepod plankton, upon which the mackerel feed, taken in the neighbourhood of the mackerel fishing grounds during the same month.

E. J. Allen (1909). Mackerel and Sunshine. Journal of the Marine Biological Association of the United Kingdom (New Series),
8 , pp 394-406
doi:10.1017/S0025315400073665

Would we know what Copepod plankton looked like if seen today?