398 AGRICULTURAL EXPERIMENT STATION. 



water is 1.9 feet. The difference between high and low water 

 in the ocean is about four feet. The variation between the 

 stream and the ocean is due to this : The stream is so narrow 

 that before the water of high tide has all run off, tide changes 

 again, backs up into the stream, and so the fall of water is not 

 great. West of 900 feet west of Ninth Avenue the stream is 

 poor. In some places a little water oozes through ; in others 

 vegetation has completely choked up the stream. The reason of 

 its having become choked is this : A stream, to be free, must 

 have a fairly good flow, or else a tide-gate to lower the level 

 of water and prevent it from standing still. The ditch has very 

 little natural fall, and besides, the tide-gate (half way between 

 Second Avenue and Seventh Avenue) has been in a useless con- 

 dition for a long time. The result is that the ditch has become 

 clogged. When it was first dug it drained the whole swamp. 

 Now it does not drain at all. 



(3) Extent of Breeding Area. 



Between Broadway and Seventh Avenue no breeding goes on. 

 W^ater rises over the land, but recedes with the ebb of the tide. 



]3et\veen Seventh Avenue and Ninth Avenue the grass growth 

 is very thick. High tide gets up here, fish are kept out by the 

 density of the vegetation and breeding goes on. This is true of 

 the land on the north side of the creek for 900 feet west of 

 Ninth Avenue. 



In that part of the swamp where the ditch has ceased to drain, 

 rains have collected and the ground is submerged, breeding going 

 on. Added to this is the backing up of water due to the poor 

 condition of the tide-gate. In the western end of the marsh 

 affairs are especially bad, there being two feet of water, and the 

 original ditch is hardly distinguishable. 



(4) What Should Be Done. Since breeding areas have re- 

 sulted from the degeneration of the ditch, evidently the thing to 

 do is to clean out the ditch. Originally it drained the marsh. If 

 cleaned, it can do so now, since no point of the marsh is lower 

 than the ditch. In conjunction with the fixing of the ditch, a 

 good tide-gate should be put in. This will lower the level of 

 the water and will keep high tides from backing into the marsh. 



(5.) It may be that when the marsh is drained, there will 

 remain separate depressions that will need ditching. Data for 

 this purpose, however, cannot be detemiined until the ditch is 

 fixed and the tide-gate put in. The immediate problem is tO' clear 

 the marsh of the surface water that is now on it. 



