SEA-FISHERIES LABORATORY. 



371 



from the yacht " Runa," during the summer, off the West 

 Coast of Scotland, and these have also been worked up and 

 reported upon in this volume. 



No change has been made in the nets employed or in 

 the method of using them (see former reports). 



Plankton of Port Erin Bay in 1913. 



As in the last few years, the plan of work has been to 

 take two horizontal (coarse and fine nets), and one vertical 

 haul twice each week throughout the year — that is, about 

 24 hauls per month. In actual practice the numbers 

 during 1913 were as follows : — 



Months 



I 



II 



III 



IV 



V 



VI 



VII 



VIII 



IX 



X 



XI 



XII 



No. of Hauls 



24 



21 



24 



24 



27 



24 



30 



24 



27 



18 



21 



18 



Over 24 hauls were thus taken in three months, and 

 less than 24 in four months. Bad weather in October and 

 December reduced the number to 18. But on the whole, 

 the work has been carried out for us by Mr. Cregeen with 

 great regularity. 



As on previous occasions the vertical hauls at the 

 mouth of the bay are found to agree very well with the 

 larger surface hauls obtained on the same occasions. 



The curve for the total plankton reaches to about 

 the same height at the vernal maximum as in 1912, but 

 the secondary rise in autumn does not this time attain to 

 half the height of that in the previous year, and to less 

 than one-fourth of the point reached at the vernal 

 maximum. 



We give here, as in previous years, a table showing 

 the monthly averages of the total catch and of the chief 



