§ Mr. Henderson Stewartasked the Secretary of State for Scotland if he will make a report on the investigations made during the past year into the failure of the winter herring fishing in the Firth of Forth; and what further investigations are contemplated.
§ Mr. WoodburnThe Research Vessel "Clupea" made a special survey of conditions within and in the neighbourhood of the Forth between 24th February and 16th April, 1948, and operated off the East Coast of Scotland in the Summer months: other ships also made observations from time to time in the Forth. The investigations have not yet been carried far enough to enable firm conclusions to be drawn. Very poor herring catches, the absence of echoes characteristic of herring shoals in an extensive echo sounding survey, combined with a complete absence of herring larvae from a series of 112 Plankton collections confirmed the scarcity of herring over the whole area. Water temperatures were normal and well within the range favoured by herring which spawn in the early Spring months. In fact, no unusual conditions were observed in the Spring of 1948 which might deter herring from using the grounds in or near the Forth Estuary as a spawning place. The Forth Spring spawners are distinct from other spawning communities in Scottish waters. None of the many samples of herring from the East or North-East Coast of Scotland examined during the Summer of 1948 included herring which showed any close "race" affinities to the Forth spawners. Whilst the evidence is still too limited for firm conclusions to be drawn there is no reason so far to suspect any geographical displacement of the Forth herring stock.
66WIt therefore seems probable that the present scarcity arises from a series of unproductive broods spawned between 1940 and 1945 or even earlier. The adult stocks were good from 1940 to 1942 as the catches in those years show, and therefore might have been expected to provide recruits for the stocks of the 1946–1947 and 1948 fisheries. The analysis of the stocks in 1948 showed, however, that the proportion of recruits from those years were most unusually low in the catches whilst we know that the adult stocks themselves had greatly decreased by 1943. As fisheries investigations were suspended on the outbreak of war it may never be possible to determine conclusively the underlying causes of the poor broods. If the same causes are still operating further investigation should reveal them; if not, the stocks of adult fish may still take a few years to return to average. Despite an improvement in the proportion of young born in 1945 their actual numbers in 1948 were so low that no appreciable improvement can safely be forecast for the season now opening.
F.R.S. "Clupea" will continue the investigations on a larger scale in 1949 and will be in the Forth from mid-January until the end of March. An extensive survey, using drift nets and echo sounders will be made within and beyond the normal fishing grounds to determine the distribution and density of the herring stocks. Research will be intensified by the participation of other research vessels when available in the neighbourhood.
It is proposed also to make a "race" analysis of the one and two year old herring now in the Firth with a view to establishing their relationships, if any, with other stocks of young herring. Material already collected by F.R.S. "Kathleen" during November, 1948, has made it possible to start this important work. As in 1948 continuous observations will be made on the hydrographical and Plankton conditions within and outside the estuary for comparison with those of other years.