114 



cycle. Hence, August water temperature 1932 was also the warmest in 40 

 years, but warmer events occurred often in subsequent decades. 



These data substantiate Rasmussens' view that 1931 and 1932 were 

 the first consecutive 2 year period of warm summers and winters in 

 decades. Nonetheless, subsequent two year periods (1949-1952, 1969- 

 1970, 1974-1975) had winter and summer water temperatures that were as 

 warm or warmer than the 1931-32 event (Fig. 21) , but no general declines 

 in eelgrass were reported in New England, or apparent on photographs of 

 Buzzards Bay. A decline between 1949 and 1952 could have gone 

 unnoticed, because eelgrass populations had only partly recovered in 

 most areas. A decline during the late 1960 's or mid-1970' s, however, 

 would have been much more apparent because eelgrass had recovered 

 considerably by that time and there had been no recent major storms or 

 ice accumulation that could cause a decline that could be mistaken for 

 disease-caused declines. 



One additional line of evidence contradicts the temperature 

 hypothesis. Past declines of eelgrass in New England (1894, and 1908) 

 reported by Cottam (1934) do not coincide with the warm summer and 

 winter pattern. In 1894, the winter was cool, and the decline came 4 

 years after a record breaking warm winter. The 1908 event was not 

 characterized by unusual weather. 



These observations do not rule out the possibility that warm 

 temperatures played a role in the 1931-32 decline, but suggest that 



