Probable Causes for the 1972 Red Tide in the Cape Ann Region of the Gulf of Maine

1973 ◽  
Vol 30 (9) ◽  
pp. 1363-1366 ◽  
Author(s):  
Hugh Francis Mulligan

Hydrographic data and spatial, temporal, and vertical distributions of Gonyaulax tamarensis are presented from the vicinity of Cape Ann, Massachusetts in summer of 1972. When considered together with available meteorological records, these data provide information on probable causes and development of the September 1972 red tide bloom in the Gulf of Maine. An upwelling of deep water, development of a "seed" population of G. tamarensis during unusually dry weather in August, and heavy rainfall in September are suggested as the three causative factors.

1993 ◽  
Vol 28 (7) ◽  
pp. 197-201 ◽  
Author(s):  
Dunchun Wang ◽  
Isao Somiya ◽  
Shigeo Fujii

To understand the algae migration characteristics in the fresh water red tide, we performed a field survey in the Shorenji Reservoir located in Nabari City, Japan. From the analysis of the field data, it is found that the patterns of vertical distributions of the indices representing biomass are very different in the morning and the afternoon. Since some water quality indices have reverse fluctuations between the surface and the bottom layer in respect of the time series changes and the total biomass of the vertical water column is relatively constant, it is concluded that vertical and daily biomass variation of red tide alga is caused by its daily migration, that is the movement from the bottom layer to the surface in the morning and the reverse movement in the afternoon.


1974 ◽  
Vol 6 (1) ◽  
pp. 76-78 ◽  
Author(s):  
John Sasner ◽  
Miyoshi Ikawa ◽  
Burdette E. Barrett
Keyword(s):  

2015 ◽  
Vol 529 ◽  
pp. 1-16 ◽  
Author(s):  
LG Waters ◽  
TG Wolcott ◽  
D Kamykowski ◽  
G Sinclair
Keyword(s):  

2015 ◽  
Vol 73 (3) ◽  
pp. 93-122 ◽  
Author(s):  
David W. Townsend ◽  
Neal R. Pettigrew ◽  
Maura A. Thomas ◽  
Mark G. Neary ◽  
Dennis J. McGillicuddy ◽  
...  

The Gulf of Maine, a semienclosed basin on the continental shelf of the northwest Atlantic Ocean, is fed by surface and deep water flows from outside the gulf: Scotian Shelf Water (SSW) from the Nova Scotian shelf that enters the gulf at the surface and slope water that enters at depth and along the bottom through the Northeast Channel. There are two distinct types of slope water, Labrador Slope Water (LSW) and Warm Slope Water (WSW); it is these deep water masses that are the major source of dissolved inorganic nutrients to the gulf. It has been known for some time that the volume inflow of slope waters of either type to the Gulf of Maine is variable, that it covaries with the magnitude of inflowing SSW, and that periods of greater inflows of SSW have become more frequent in recent years, accompanied by reduced slope water inflows. We present here analyses of a 10-year record of data collected by moored sensors in Jordan Basin in the interior Gulf of Maine, and in the Northeast Channel, along with recent and historical hydrographic and nutrient data that help reveal the nature of SSW and slope water inflows. We show that proportional inflows of nutrient-rich slope waters and nutrient-poor SSWs alternate episodically with one another on timescales of months to several years, creating a variable nutrient field on which the biological productivities of the Gulf of Maine and Georges Bank depend. Unlike decades past, more recent inflows of slope waters of either type do not appear to be correlated with the North Atlantic Oscillation (NAO), which had been shown earlier to influence the relative proportions of the two types of slope waters that enter the gulf, WSW and LSW. We suggest that of greater importance than the NAO in recent years are recent increases in freshwater fluxes to the Labrador Sea, which may intensify the volume transport of the inshore, continental shelf limb of the Labrador Current and its continuation as the Nova Scotia Current. The result is more frequent, episodic influxes of colder, fresher, less dense, and low-nutrient SSW into the Gulf of Maine and concomitant reductions in the inflow of deep, nutrient-rich slope waters. We also discuss evidence that modified Gulf Stream ring water may have penetrated to Jordan Basin in the summer of 2013.


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