FISHERY BULLETIN: VOL. 79, NO. 4 



Figure 9. — Commercial landings of 

 blue crab in Delaware, 1887-1977. 



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90 1900 10 20 30 40 50 60 



YEAR 



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mosquitoes on coastal marshlands may have been 

 a factor. It is suggestive in that blue crab has 

 returned in great abundance to Delaware, New 

 Jersey, New York, and even farther north. On the 

 other hand, its abundance is obviously affected 

 adversely by cold winters, such as the winter of 

 1976-77, which killed many of the blue crabs in 

 New York waters. It is expected that blue crab will 

 continue to be highly variable in abundance from 

 Delaware north. At present, however, it is the 

 most important fishery in the area. 



Blue crab is an important predator of hard clam 

 wherever it is abundant. In areas where extensive 

 hard clam fisheries exist, or where the potential 

 for hard clam production is high, it might be well 

 to encourage fisheries for blue crab, and to place 

 no limits on the catch, because there is an estab- 

 lished and valuable fishery for hard clam, and the 

 two may not be able to coexist in abundance. 



American Oyster 



The American oyster industry in Delaware was 

 rather small for most of its history, taking most of 

 its harvest from naturally producing grounds in 

 the State. Prior to 1929 its history is not clear 

 because landings were available for only 14 of the 

 49 yr. It appears that it peaked somewhere be- 

 tween 1912 and 1926 (Figure 10), then dropped off 

 to low levels until after the Second World War. For 

 about 12 yr, from 1947 to 1958, it fluctuated 

 from about 900 to 1,800 t (2 to 4 million lb), then 

 dropped abruptly, and since then has been <225 t 

 (500,000 lb) except for 1 yr. Poor management, 

 followed by disease, were the principal causes, 

 according to Daiber (footnote 4). 



Price (1978) has noted that in the late 1800's, 

 Delaware Bay as a whole (New Jersey and Dela- 

 ware) produced about 10,423 t (23 million lb) 



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Figure lO. — Commercial landings of 

 American oyster in Delaware, 



1880-1977. 



80 90 1900 10 20 30 40 50 



YEAR 



60 70 



584 



