Notes and Memoranda

Extract

Probable Relation between Temperature and the Annual Catch of Anchovies in the Schelde District (with Pl. XXIV).—Mr. C. J. Bottemanne, of Bergen-op-Zoom, the Inspector of Fisheries for Holland, has expressed in tables published in extenso in the Verslag omtrent den Toestand der Visscherijen in de Schelde en Zeeuwsche. Stroomen for 1888, some very interesting statistics which have been condensed in Pl. XXIV of this journal. The temperature observations were made on the Rinkelaar guardship of the Ijerseke Bank of the Eastern Schelde (see Map, Pl. XXI); the amounts of the annual catch are taken from the official returns. It appears probable from these statistics that the extent of the catch of anchovies in the Schelde district in any year is (at least largely) dependent on the temperature of the water during the midsummer months of the preceding year. The curves in Pl. XXIV exhibit the temperature on the Ijerseke Bank during the months June to September from 1883 to 1888, the shaded blocks below them represent graphically the mass of anchovies taken in the succeeding year, i. e. 1884—1889 (the figures in the bottom line placed after the year indicate the total number of barrels). The only apparent exception is 1886, but, though the highest recorded temperature of this year is not great, the mean temperature in July to September was extremely and unusually high, as will readily be seen in the diagram. As an example of the valuable information which scientific observers may give to those interested in fisheries, Mr. Bottemanne, on receiving the statistics of temperature for 1888, warned the fishermen of the district last year not to go to trouble orexpense about the anchovy, fishery; they persisted, however, and justified his advice by realising 12 barrels as against 730 barrels of the previous year.