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and to the extremity of the bay on the south. The great amount of area drained 

 at each low tide produces results of great importance to edible shellfish, namely 

 a great variation in temperature, very swift currents in portions, and a high salinity. 

 Tlie currents probably result in the destruction of a great amount of spawn, as 

 a great deal must be washed out to sea. This may in part explain the distribution 

 of the soft shell clam. The currents in the long central part of the bay, and the 

 narrow beaches left by them, prevent the formation of any extensive clam beds, 

 so that there are only two parts of the bay of importance from our standpoini, 

 namely, the two broad extremities. The bottom is a fine deep sticky mud, finest 

 at the extremity of the bays, where deposition has at one time taken place and has 

 not been subsequently eroded. The bay side of the spits are of a sandy character 

 owing apparently to the carrying over of sand by the wind. 



The distribution of the clams seems to differ in the two ends of the bay, due 

 to the differences in depth, supply of fresh water, and nianner of drainage. No 

 important beds of clams are to be found in North Bay save the extensive ones of 

 Mi/a arenaria along its northern shore. The extensive beds of clams in South Bay 

 lie, in a fashion contrary to that of the clams in North Bay, along the edges of the 

 tidal flats nearest the entrance, but this may be explained by the fact that the 

 species are different and require different beds. Back of these beds on the margin 

 of the flats in South Bay are found areas which maj^ once have been occupied by 

 the native species of clams now found only along the edges, as may be seen by 

 the presence of great numbers of empty shells buried in natural positions. Far 

 back, along the shore itself are found areas sparsely inhabited by living Mya. There 

 is no apparent reason why the extensive intermediate flats now vacant could not 

 be made use of for the growth of young transplanted Mya if such should be found 

 profitable. 



The beds of Mya arenaria in Humboldt Bay are the most important ones in the 

 noithern portion of California, the clams being dug extensively for the market. The 

 bed used is that extending from the Mad River sloughs to the far eastern part of 

 the bay. In no place are they in real abundance, as in San Francisco Bay, but 

 •they are scattered, sparsely in general, save along the slough-like channels. In 

 ordinary tides, a stretch of beach about 500 yards wide and two or two and a half 

 miles long is exposed. At the best a bucket full of clams may be dug within two 

 square yards. Tlie local diggers state that at one time the Mad River sloughs had 

 an abundance of clams but they are not now of commercial importance. They were 

 probably affected by the closui-e of the river. Along the flats forming the eastern 

 side of the bay, between Indian Island and the Areata shore, occasional Mya are 

 found, but no ijeds which are used commercially. In South Humboldt Bay there are 

 a few scattered along the shore line away from the channels, and a few in the 

 shallower sloughs, but not enough to be considered of importance. Although it must 

 be concluded that the supply of clams in Humboldt Bay is not extensive enough to 

 yield a great supply, yet they are of good quality and capable of supplying enough 

 clams for two or three diggers. 



3. Big and Stone lagoons. Small areas populated by Mya exist in Big and 

 Stone lagoons. No traces were found of clams in Freshwater Lagoon, nor of 

 anyone who could vouch for their presence. These lagoons are somewhat of the 

 type of Lake Earl, closed by a sandbar, with brackish water, and opened annually 

 to the ocean by the winter rains. At the time they were visited, the difference in 

 salinity between their waters and those of the ocean was very marked, the spits 

 not being open. The shells of Mya found were of very small size. 



4. Eel River. The sloughs of Eel River may be considered as providing a small 

 supply of clams to augment that for the markets of Eureka. They are fairly 

 accessible, but are not very abundant save in small areas. The beds lie along the 

 narrow tidal slopes of the sloughs extending into the northern and southern extrem- 

 ities of the main slough (McNulties). Of these. Hawk and Seven Mile sloughs are 

 the best. Along Eel River proper the beds are absent, because of the swift currents 

 of fresh water. The shifting of the entrance to the river, which was at one time 

 farther north than at present, has resulted in the formation of these sloughs. The 

 sandy spit is easily shifted, and on digging into the beaches successive layers of 

 mud and sand may be found, showing that previous shifts in the river have had 

 extensive effects on the character of the beds. However, there is a moderate supply 

 of Mya here, available if properly cared for, and capable of being increased to a 

 considerable extent by culture. The diking off of the slough ends has resulted in 

 the loss of some of the available area. 



5. Mouth of Ten Mile River. There is found here a small bed of Mya, not of 

 commercial importance. The available area is small, but the clams are occasionally 

 dug by the local inhabitants. 



6. Navarro River. A supply somewhat similar to that of Ten Mile River is 

 found. 



7. Big River. A number of beds are found in the bends of the river, where 

 mud flats have been deposited, between a half to three miles from the mouth. They 

 are much gathered for local use, but are not sold in the markets. The Chinese use 



