WCA - Everglades Conditions Update

(May 6, 2008)

 

Rainfall:

Very little rain fell last week across the Everglades ranging from 0.01” to 0.53”. This was very similar to last week, except in the region of NE Shark River Slough (see attached gif).

WCA-1:          0.03”               WCA-3A:       0.27”

WCA-2A:       0.01”               WCA-3B:        0.53”

WCA-2B:        0.09”               ENP:               0.43”

The mean 7 day evapotranspiration for the region was 1.8”; see srs pdf.

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Water Conservation Areas:

Recession rates were excellent in almost all the WCA’s. Only NE Shark River Slough and WCA-3B had rainfall quantities sufficient to cause slight reversals. However, large regions of the WCA’s continue to exhibit depths greater than 1 ft (see attached WCA Stages.xls). Depths greater than one foot are inhospitable for wading bird foraging. Stages in WCA-1 have declined and are at Regulation, WCA-2A marsh remains well above regulation and WCA-3A stages are within zone E1 of the regulation schedule (see WCA_reg_stages.doc), for protection of the Cape Sable Seaside Sparrow.

 

Everglades National Park:

Patterns for ENP wetland water levels followed those for rainfall (areas that saw rain were up, while other areas w/o precip declined).  Nearly 1.5” of rainfall in Shark River Sl. (station P33) allowed water levels here to increase for the week by 1.3”.  Fueled by low rain & high ET, water level was down for a second week by nearly 5” over the 7 d period at Taylor Sl. Bridge (not an unusual recession rate at this station).  The southern part of Taylor Sl. (at Craighead Pond) also posted declining water levels, down by 1.7” for the 7 d period. 

 

Salinity in Florida Bay increased slightly last week.  Salinity rose into the mid-30s at Trout Ck and into the lower 30s at the mouths of Taylor River & L. Madeira Bay.  In the Taylor ponds, salinity approached 30 psu at Pond 5 (USGS station) and Argyle Hendry (ENP station TR).  As of Sunday, 5/4, the 30d moving average concentration at TR (used for tracking the FL Bay MFL criterion) was at 22.4 psu (up from 20.3 psu last week, and while not unseasonably high, the highest concentration we have seen yet this dry season).  Salinity also increased in the northcentral Bay areas of McCormick Ck. & Terrapin Bay, where concentrations once rose into the upper-30s by the week’s end.  At the central Bay station in Whipray Basin salinity held in the mid-upper 30s for another week, though in shallower areas to the northwest (in Rankin Lake), our Dataflow field crew measured concentrations closer to 50 psu last week (we will have add’l data to report from this trip in next week’s update).  These salinity concentrations across FL Bay are near seasonal norms.  Despite being above average for much of the dry season, salinity in the upstream reaches of Shark River (Tarpon Bay platform) measured near its seasonal norm (mid-teens) for another week.

 

 

Wildlife:

Friday’s monthly colony survey revealed that the recent improvements in hydrologic conditions have not initiated a late surge in nesting activity.  A total of 1195 nests (795 egrets and 400 White Ibis nests) were counted. 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 (see attached table for more details). Most nesting activity is in the Refuge.  

 

Most areas of the WCAs supported low numbers of foraging birds. Very few birds were seen in WCA-3A or WCA-2A and most activity was seen in the northern Refuge (see attached table for more details).

 

Below is a summary of the nest numbers for each colony. Attached is a spreadsheet comparing nest numbers between 2006, 2007 and this year, a map showing colony locations, and a summary graphic in PowerPoint. Please contact Mark Cook if you have any questions. 

 

Alley North Colony

No nests. Approximately 35 Great Egret pairs have abandoned this colony since last month’s flight.

 

Cypress City

No nests. Approximately 20 Great Egret have abandoned this colony since last month’s flight

 

6th Bridge

40 Great/Snowy Egret nests

25 tricolor Herons

 

Crossover

No nests

 

Jetport

No nests

 

Hidden

No nests

 

Tamiami West

No nests

 

Tamiami East

No nests

 

Heron Alley

No nests

 

3B Mud East

No nests

 

Big Mel’

No nests

 

Colony 99

300 Great/Snowy Egret nests

100 White Ibis nests

 

Colony 73

30 Great Egret nests

300 White Ibis nests

 

Colony 70

No nests

 

Colony 111

No nests

 

New Colony 1

No nests

 

New Colony 2

100 Great/Snowy Egret nests

 

New Colony 3

No nests

 

New Colony 4

200 Great/Snowy Egret nests

100 Tricolor Heron nests

 

Canal N

No nests

 

 

 


 

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