Paul,-J.H.; Rose,-J.B.; Jiang,-S.C.; Kellogg,-C.A.; Dickson,-
	L.  Distribution of viral abundance in the reef 
	environment of Key Largo, Florida.  APPL.-ENVIRON.-
	MICROBIOL. 1993. vol. 59, no. 3, pp. 718-724.

The distribution of viral and microbial abundance in the Key 
Largo, Fla., reef environment was measured. Viral abundance 
was measured by transmission electron microscope direct 
counts and plaque titer on specific bacterial hosts in water 
and sediment samples from Florida Bay (Blackwater Sound) and 
along a transect from Key Largo to the outer edge of the reef 
tract in Key Largo Sanctuary. Water column viral direct 
counts were highest in Blackwater Sound of Florida Bay (1.2 x 
10 super(7) viruses per ml), decreased to the shelf break 
(1.7 x 10 super(6) viruses per ml), and were inversely 
correlated with salinity (r = -0.97). Viral direct counts in 
sediment samples ranged from 1.35 x 10 super(8) to 5.3 x 10 
super(8)/cm super(3) of sediment and averaged nearly 2 orders 
of magnitude greater than counts in the water volumn. Viral 
direct counts (both sediment and water column measurements) 
exceeded plaque titers on marine bacterial hosts (Vibrio 
natriegens) and others) by 7 to 8 orders of magnitude. Water 
column viral abundance did not correlate with bacterial 
direct counts or chlorophyll a measurements, and sediment 
viral parameters did not correlate with water column 
microbial, viral, or salinity data. Coliphage, which are 
indicators of fecal pollution, were detected in two water 
column samples and most sediment samples, yet their 
concentrations were relatively low (< 2 to 15/liter for water 
column samples, and < 2 to 108/cm super(3) of sediment). Our 
findings indicate that viruses are abundant in the Key Largo 
environment, particularly on the Florida Bay side of Key 
Largo, and that processes governing their distribution in the 
water column (i.e., salinity and freshwater input) are 
independent of those governing their distribution in the 
sediment environment.