EARLY PROBLEMS 23 



was a good growth of Potamogetons. Potamogeions, especially P. pectinatus, 

 require special emphasis in connection with this project, for they are prime 

 duck food plants, furnishing as they do both seeds and tubers; in the days 

 of thriving gro^\i;h they constituted the greater part of the plants of these 

 waters. McAtee says that in 1909 P. pectinatus alone comprised 60 per cent 

 of the abundant duck feed in Currituck Sound. 



Bourn found the oxygen content of these waters low and the carbon diox- 

 ide content high. This was especially true of the water of the northern part 

 of Currituck Sound and of the canal. He thinks neither of these, as such, sig- 

 nificantly limited the growth of green aquatic plants and that both would 

 have changed if other growth conditions had been favorable. The situation 

 was different with fish. The oxygen content of the water was so low that 

 only low-oxygen-requiring herbivorous fish were present in any abundance 

 and these were minor destructive agents to plants. The high-oxygen-requir- 

 ing, plankton-consuming fish were scarce and consequentl}^ did not compete 

 \\ath the hydroid for plankton food. 



During his studies in the region. Bourn cut off several coves from the main 

 body of water by means of bulkheads and watched the natural recovery of 

 vegetation in these protected coves or the development of re-set plants or 

 sown seeds in them. In these protected areas, provided the water was not 

 too shallow, the water plants thrived and finally gave a good stand of vege- 

 tation. Also the turbidity of the waters in these coves disappeared soon after 

 the construction of the protecting bulkheads. This was true in spite of the 

 fact that the bulkheads were not water-tight but allowed some movement 

 of water, as was shown by the fact that the change of water level in the en- 

 closed areas always accompanied that in the main body of water. 



The District Army Engineer stated in 1922 ^- p-^^: "the salinity of 

 Currituck Sound is caused not by accession of salt from the north or through 

 the Albemarle and Chesapeake Canal, but from salt water washing over 

 the beach into Currituck Sound at times of storm, and from Oregon Inlet." 

 The Oregon Inlet through the sand bar opens into the north part of Albe- 

 marle Sound. When the evidence was all in, the Army Engineers reversed 

 themselves on this point and expressed themselves as in agreement with 

 the conclusions of the Institute. This is showm by a quotation from the re- 

 port in 1929 of Major General H. Taylor, U. S. A., Retired, formerly Chief 

 of Engineers. He says ^' p-^^: 



"The Division Engineer seems to agree with this view, for he says: 'Con- 

 sidering the possible reasons for the present salinity in these waters, the 

 salt water from Oregon Inlet, the sea washing over the beach, the seepage 

 through narrow parts of the beach and from a salt water table can be disre- 

 garded, as there is nothing to show that there has been any increase in salin- 

 ity from these sources. In fact, there should be a decrease, as Oregon Inlet 

 is said to be smaller than in former years and the beaches have been con- 

 siderably improved by sand-fence construction.' 



"Among the papers submitted in connection with this case is a report sub- 



