RAPPORTS. Xril Cl: MASTERMAN — 4 — 



PART I 



SUMMARY AND DISCUSSION OF RESULTS 



Special Statistics 

 A. Special Returns of Selected Vessels 



In last year's Report the term /-'Special. Statistics", was defined to include "more de- 

 tailed or more authenticated returns of commercial vessels than it is possible to obtain 

 by ordinary commercial market-statistics". These details may involve data of the actual catch 

 of fish with respect to size, weight, age and sex, the duration of haul, and the place of 

 capture. The Reports under consideration this year include some important series of spe- 

 cial returns. Firstly (2 d), there have appeared the records of the trawling investigations 

 of the English investigation-steamer for the years 1904—5. The information is given 

 under three heads, namely, I. Particulars of Trawling Statistics, II. Detailed measurements 

 of Plaice measured, and III. Summaries giving the number of fish of each kind in 10 cm. 

 groups, for each haul. No attempt has been made in the Report itself to employ the 

 data for eliciting specific information though it is clear that they will prove of value for 

 the determination of certain facts. They include data of the direction and duration of 

 haul, nature of the bottom and the bottom fauna, with' details of the tide, sea and weather, 

 for each haul of forty-two voyages. Similar data will soon be available for the years 

 1906—9 when an -attempt will have to be made to employ them for solution of specific 

 problems. The part under Head II already forms a contribution towards treatment of the 

 plaice problem, available for discussion elsewhere. 



Another Report (2 c) embodied in the General English Report deals with special sta- 

 tistics obtained from certain selected English sailing trawlers fishing out of Lowestoft, in 

 the Southern North Sea. A detailed return was obtained for each haul of the net from 

 each of three selected skippers, covering a period of four years (1903— 6). In last year's 

 report was given (Fig. 4) a chart showing the limits of the area fished over, as a rule, 

 by the Lowestoft fishermen ; the detailed records here discussed appear to cover much 

 the same waters, lying within a radius of 80 miles from Lowestoft and between latitude 

 53° 30' N. and latitude 51° 30' N. This area is especially interesting from the point of view 

 of this report, includ as it does the most important pleuronectid fishery of the North 

 Sea. The total number of hauls in the four years is 4,794, which are found sufficient to 

 determine certain general features of the fishing operations. 



It is found that the average duration of a haul is about 6 — 7 hours (the period of a 

 tide) though it may vary widely from 3 — ^12 hours, and according to the fancy or habit 

 of the skipper, hence the catch per six hours' fishing is adopted 'as a unit. The author 

 has been enabled to divide the area into nine sub-areas which, although they are not 

 effectively sampled in every case, help to shew certain characters. For example, it is 

 shewn that the percentage amount of fishing taking place on each of these sub-areas is 

 •fairly constant over the four years, so that any variations in the yearly catch cannot be 

 accounted for by a change of fishing from one sub-area to another. In the present 



