I shall elucidate the subject of the causes of the apparent diminution in the mackerel supply off this coast by an example which will de facto point out how this fish can be readmitted as an economic sea product for our food supply; and in so doing I shall draw almost entirely from my research in the matter as contained in the paper to which I have referred.
About thirty years ago the mackerel fishery off the southern Irish coast was first (in this century) prosecuted as a great industry. Fishing vessels came there from Scotland, England, the Isle of Man, and from France, to reap the silvery harvest of the ocean; and the few rude native craft which then existed were rapidly multiplied into hundreds of beautiful yacht-like fishing vessels. For twenty years the mackerel fishing—which begins in March and continues until the end of June—prospered almost phenomenally, and many of the boat-owners and fishermen, both native and foreign, amassed comparative wealth, as did also the ship-builders and net and rope makers. The town of Kinsale, county of Cork, which is the headquarters of the industry, enjoyed a prosperity during those years strangely at variance with the decaying condition of other Irish towns; but in 1880 this great fishery was temporarily destroyed, through sheer ignorance of the habits and instincts of the mackerel, by the avarice of the boat-owners and fishermen of the Isle of Man.
It occurred in this way: All the fishermen of this great fleet—over one thousand fishing vessels, each carrying eight to ten men and more than two miles of netting—were aware that the mackerel came from the Atlantic, in the southwest and west, toward their spawning ground off the southern Irish coast at this season. But the Manx fishermen and owners were not satisfied with reaping a good harvest from March to June. The fish fetches a much larger price early in the season, and they decided that they would "try" for them farther west than the usual fishing ground, before the season opened off Kinsale and Baltimore. The result was disastrous. For two years the "early boats" succeeded well; but in the third year the entire mackerel fishing along the coast was a failure, and it was not until May and early in June that good catches were made off the "grounds" outside Kinsale. Then the price was low, as the fish was too full of roe, or "spent" after spawning, to be shipped to foreign markets in good condition, and one after another the boat-owners and fishermen and merchants fell before the unprosperous wave. The fact of the mackerel not turning up until late in the season caused sore distress among the eight or ten thousand persons engaged in the industry; but it had one good effect—it stopped the too early fishing; and now, after eight years of failure, prosperity is again beginning to dawn upon the southern Irish fisheries.