OBSERVATIONS IN RAMBHA BAY. 



The main object of this paper is twofold ; firstly to describe the differences in 

 density found in the water of the inner part of the Chilka Lake at different levels 

 and secondly to put on record changes in the composition of the invertebrate fauna 

 noted in the same local^, in a year in which the density of the water as a whole 

 was considerably below normal. 



It was noted in August, 1919, that the water of Rambha Bay, which forms the 

 south-western extremity of the Chilka Lake, was apparently much less salt than it 

 had been at the same season or a little later in 1914, when Annandale and Kemp 

 concluded their investigation of the fauna of the lake. For various reasons it was 

 impossible to carry out another survey of the lake as a whole, but arrangements 

 were made for observations on the bay at different seasons with Barkuda Island as 

 our headquarters. 



We were unable to visit the mouth of the lake, but trusted to obtaining informa- 

 tion from official sources as to its condition at the time. In this we have been to 

 some extent disappointed. We have to thank the Director of Fisheries, Bengal, 

 Bihar and Orissa, and also the Executive Engineer, Cuttack, for supplying us with such 

 facts as were known to the departments concerned. They have spent much time and 

 labour in doing so, but unfortunately no inspection seems to have been made at the 

 critical period at which we believe that channel became closed, i.e. towards the end 

 of the dry season. The mouth is known to have been open in April, 1919 and in the 

 same month of 1920, and changes in its position are known to have occurred in the 

 former year. We have little doubt that it was closed for a considerable period in the 

 summer or autumn of 1919, in which low density was associated with exceptionally 

 high water in a season of by no means excessive rainfall. We were informed by the 

 serang of the Rajah of Kallikota's steam launch, who is well acquainted with all 

 parts of the lake, that the channel was entirely blocked in November, 1919, but 

 this is contradicted by other statements. In the rainy season of 1920 conditions 

 apparently became normal again. 



Part I. HYDROGRAPHY. 



By R. B. Seymour Seweel. 

 The present investigations were undertaken by me in order to supplement the 

 work done by Dr. N. Annandale and Dr. S. W. Kemp l during their survey of the 

 Chilka Lake in 1914. The conclusions at which these investigators arrived were 



1 Annandale and Kemp : "Fauna of the Chilka Lake, Introduction, Hydrography of the Lake,' 

 Mem. Ind. Mus. pp. 5-12, Vol. V (Calcutta, 1915). 



