WCA - Everglades Conditions Update

(May 13, 2008)

 

Rainfall:

Very little rain fell for a third consecutive week across the Everglades. Rainfall ranged from 0.01” to 0.43”. Rainfall was confined to the northern region of the LNWR and a narrow band in WCA-3A (see attached gif).

WCA-1:          0.43”               WCA-3A:       0.22”

WCA-2A:       0.17”               WCA-3B:        0.04”

WCA-2B:        0.02”               ENP:               0.01”

The mean 7 day evapotranspiration for the region was high at 2.07” (see srs pdf).

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Water Conservation Areas:

Recession rates were excellent in almost all the WCA’s for a third consecutive week. In a few regions the recessions were actually a little too high but not a concern since water depths are in general, still too high (<1.0 ft) for wading bird foraging, especially in WCA-3A (see attached WCA Stages.xls). Stages throughout the WCA’s continue to decline and are close to Regulation in WCA-2A  and WCA-3A. The WCA-2A marsh has been well above regulation for at least; the last three months (see WCA_reg_stages.doc).

 

Everglades National Park:

Little rainfall & high ET caused water levels to decline across ENP wetlands last week.  Water level dropped by 2.9” over the 7 d period at Taylor Sl. Bridge (not an unusual recession rate at this station), and by 1.9” in the southern part of Taylor Sl. (at Craighead Pond, a more substantial decline for this area – see stages.pdf).  The weekly decline 0.4” in Shark River Sl. (station P33) was lower than that for other stations because of high rainfall in this area the week prior.

 

Salinity in Florida Bay either remained stable or increased (see Salinity.pdf).  Bay salinity typically peaks during this time of the year, when evaporation is very high & the rains have yet to kick in; concentrations herein described are near seasonal norms.  Salinity held in the mid-30s at Trout Ck and in the lower 30s at the mouths of Taylor River & L. Madeira Bay.  In the Taylor ponds, daily mean salinity reached over 30 psu at Pond 5 (USGS station) and Argyle Hendry (ENP station TR).  As of Sunday, 5/11, the 30d moving average concentration at TR (used for tracking the FL Bay MFL criterion) was at 24.6 psu (up from 22.4 psu last week).  At the central Bay station in Whipray Basin salinity approached 40 psu by the end of last week.  Salinity in the upstream reaches of Shark River (Tarpon Bay platform) measured slightly above the seasonal norm (mid-teens) last week, reaching just over 20 psu as of Sunday, 5/11.

 

Recent synoptic mapping indicate that chlorophyll concentrations are approx. ½ of what they were earlier this year in eastern areas of FL Bay. In the central Bay; chlorophyll remains fairly low (< 5 ug/L). The southern bloom region near Twin Key Basin was not mapped.

 

 

Wildlife:

Last week a total of 1195 nests (795 egrets and 400 White Ibis nests) were reported. This is almost double last month’s count but considerably lower than both the May 2006 and May 2007 counts when 36625 and 7170 nests were observed, respectively. This week a new large colony of some 4500 nests (mostly White ibis) was observed at the Lox West location of the LNWR (see colony map.jpg)

 

 

 

 


 

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