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Blackburn Bay Condition Report for 2013

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Pass

3 out of 3 indicators were rated as PASS.

All three indicators must pass
for the bay to be rated as PASS.

Learn more about how this report is created

Summary:

The overall health of Blackburn Bay has remained in good condition with two out of three water quality parameters, chlorophyll a and phosphorus, below their associated target levels. Nitrogen concentration rose sharply in the latter part of 2013, pushing the annual mean above target levels.

Water Quality: All three water quality indicators (chlorophyll a, nitrogen, and phosphorus) were rated as pass (concentration below the threshold). The mean for chlorophyll a was calculated as an arithmetic mean and the means for nitrogen and phosphorus were calculated as geometric means (per the Numeric Nutrient Criteria outlined in the Florida Administrative Code, section 62-302.532). The mean chlorophyll a level (0.0054 mg/l) in Blackburn Bay has decreased and was scored as excellent, below both the target (0.006 mg/l) and threshold (0.0082 mg/l) levels. The mean nitrogen level (0.4201 mg/l) has greatly increased but still retained its “Good” score as it is below the threshold level of 0.430 mg/l. Phosphorus concentrations in the bay have remain relatively constant and low, with a mean of 0.0556 mg/l, below the target (0.1700 mg/l) and threshold (0.210 mg/l) levels and earning a score of “Excellent”.

Biotic Indicator: Measurement of the biotic indicator, seagrass, is performed at two-year intervals and is due for monitoring again in 2014. When last assessed in 2012, total seagrass acreage in Blackburn Bay was 324 acres, below the target level of 447 acres.

Bay Location Map

Bays included in this report:

Water Chemistry Ratings

Total nitrogen, total phosphorus, and chlorophyll a levels are monitored carefully by water resource managers and used by regulatory authorities to determine whether a bay meets the water quality standards mandated by the Clean Water Act. The trend graphs for these indicators are shown below, along with their target and threshold values. A target value is a desirable goal to be attained, while a threshold is an undesirable level which is to be avoided. Learn More about these ratings and how they are calculated »

The Five-year Trend Graphs below illustrate the general trend of water quality parameters. They show a six-month running average, which moderates high and low values in the data.

Excellent

Chlorophyll a

Score: Excellent How was this determined?
Units: mg/l Year
2013
Historical
period of record
High 0.0194 0.043
Mean 0.0054 0.005 0.00487814 0.0060000000
Low 0.0014 0.0002
No. of Samples 60 841

Five-year Trend Graph

     
1/1/20091.5450.0015400mg/l
2/1/20091.7650.0016500mg/l
3/1/20091.0350.0014400mg/l
4/1/20094.2450.0021400mg/l
5/1/20092.3450.0021800mg/l
6/1/20093.7940.0024500mg/l
7/1/20095.4950.0031100mg/l
8/1/20097.2150.0040200mg/l
9/1/20093.9750.0045100mg/l
10/1/20096.5350.0048900mg/l
11/1/200913.6450.0067700mg/l
12/1/20094.3050.0068600mg/l
1/1/20102.8850.0064200mg/l
2/1/20104.2050.0059200mg/l
3/1/20101.8040.0055600mg/l
4/1/20105.7550.0054300mg/l
5/1/20102.9050.0036400mg/l
6/1/20108.6440.0043600mg/l
7/1/20105.8740.0048600mg/l
8/1/20108.5840.0055900mg/l
9/1/20109.7650.0069200mg/l
10/1/20108.6250.0074000mg/l
11/1/20108.2550.0082900mg/l
12/1/20108.8150.0083200mg/l
1/1/20111.7050.0076200mg/l
2/1/20112.2650.0065700mg/l
3/1/20112.4740.0053500mg/l
4/1/20118.3350.0053000mg/l
5/1/20113.6150.0045300mg/l
6/1/20112.0750.0034100mg/l
7/1/20113.3750.0036900mg/l
8/1/20116.4050.0043800mg/l
9/1/20118.8750.0054400mg/l
10/1/20115.9650.0050500mg/l
11/1/20114.3250.0051700mg/l
12/1/20112.3740.0052200mg/l
1/1/20122.8950.0051400mg/l
2/1/20123.8950.0047200mg/l
3/1/20123.4250.0038100mg/l
4/1/20124.0850.0035000mg/l
5/1/20121.5450.0030300mg/l
6/1/20121.8950.0029500mg/l
7/1/20125.9550.0034600mg/l
8/1/201216.6550.0055900mg/l
9/1/20126.6650.0061300mg/l
10/1/20126.4950.0065300mg/l
11/1/20127.0340.0074500mg/l
12/1/20121.6240.0074000mg/l
1/1/20134.7050.0071900mg/l
2/1/20132.0750.0047600mg/l
3/1/20132.1550.0040100mg/l
4/1/20131.7350.0032200mg/l
5/1/20132.7050.0025000mg/l
6/1/20133.2550.0027700mg/l
7/1/201311.5650.0039100mg/l
8/1/20136.2850.0046100mg/l
9/1/20137.0850.0054300mg/l
10/1/201310.9450.0069700mg/l
11/1/20138.0150.0078500mg/l
12/1/20134.1250.0080000mg/l
Loading Chart...
Target
0.006 mg/l
Threshold
0.0082 mg/l
Good

Nitrogen, Total

Units: mg/l Year
2013
Historical
period of record
High 2.205 2.205
Mean 0.4201 0.18407155 0.3600000000
Low 0.185 0.055
No. of Samples 60 828

Five-year Trend Graph

     
1/1/2009269.0050.2690000mg/l
2/1/2009317.0050.2930000mg/l
3/1/2009323.0050.3030000mg/l
4/1/2009345.0050.3135000mg/l
5/1/2009267.5040.3043000mg/l
6/1/2009340.0040.3102500mg/l
7/1/2009269.0050.3102500mg/l
8/1/2009235.0050.2965800mg/l
9/1/2009282.7540.2898800mg/l
10/1/2009232.5040.2711300mg/l
11/1/2009429.0050.2980400mg/l
12/1/2009417.0050.3108800mg/l
1/1/2010287.4050.3139400mg/l
2/1/2010307.8050.3260800mg/l
3/1/2010205.0040.3131200mg/l
4/1/2010636.4050.3804300mg/l
5/1/2010345.0050.3664300mg/l
6/1/2010442.5040.3706800mg/l
7/1/2010255.2540.3653300mg/l
8/1/2010265.0040.3581900mg/l
9/1/2010380.8050.3874900mg/l
10/1/2010307.0050.3325900mg/l
11/1/2010669.0050.3865900mg/l
12/1/2010475.0050.3920100mg/l
1/1/2011229.0050.3876300mg/l
2/1/2011259.4050.3867000mg/l
3/1/2011367.0050.3844000mg/l
4/1/2011443.4050.4071300mg/l
5/1/2011415.8050.3649300mg/l
6/1/2011367.0050.3469300mg/l
7/1/2011275.0040.3546000mg/l
8/1/2011401.0050.3782000mg/l
9/1/2011545.8050.4080000mg/l
10/1/2011335.0050.3899300mg/l
11/1/2011337.6050.3769000mg/l
12/1/2011329.4050.3706300mg/l
1/1/2012341.0050.3816300mg/l
2/1/2012385.2050.3790000mg/l
3/1/2012413.0050.3568700mg/l
4/1/2012245.0040.3418700mg/l
5/1/2012245.0050.3264300mg/l
6/1/2012229.0050.3097000mg/l
7/1/2012540.4050.3429300mg/l
8/1/2012566.0050.3730700mg/l
9/1/2012499.8050.3875300mg/l
10/1/2012521.0050.4335300mg/l
11/1/2012360.7540.4528300mg/l
12/1/2012233.0040.4534900mg/l
1/1/2013319.0050.4165900mg/l
2/1/2013289.0050.3704300mg/l
3/1/2013205.0050.3212900mg/l
4/1/2013291.0050.2829600mg/l
5/1/2013351.0050.2813300mg/l
6/1/2013320.0050.2958300mg/l
7/1/2013565.0050.3368300mg/l
8/1/2013546.6050.3797700mg/l
9/1/2013612.8050.4477300mg/l
10/1/2013913.4050.5514700mg/l
11/1/2013863.0050.6368000mg/l
12/1/2013445.0050.6576300mg/l
Loading Chart...
Target
0.36 mg/l
Threshold
0.43 mg/l
Excellent

Phosphorus, Total

Score: Excellent How was this determined?
Units: mg/l Year
2013
Historical
period of record
High 0.16 0.53
Mean 0.0675 0.06898425 0.1700000000
Low 0.05 0.05
No. of Samples 57 809

Five-year Trend Graph

     
1/1/200968.0050.0680000mg/l
2/1/200962.5040.0652500mg/l
3/1/200980.0040.0701700mg/l
4/1/200987.5040.0745000mg/l
5/1/200950.0040.0696000mg/l
6/1/200950.0040.0663300mg/l
7/1/200960.0040.0650000mg/l
8/1/200952.5040.0633300mg/l
9/1/200955.0040.0591700mg/l
10/1/200962.0050.0549200mg/l
11/1/200962.0050.0569200mg/l
12/1/200962.0050.0589200mg/l
1/1/201050.0040.0572500mg/l
2/1/201052.5040.0572500mg/l
3/1/201052.5040.0568300mg/l
4/1/201080.0040.0598300mg/l
5/1/201052.5040.0582500mg/l
6/1/201050.0040.0562500mg/l
7/1/201055.0040.0570800mg/l
8/1/201050.0030.0566700mg/l
9/1/201074.0050.0602500mg/l
10/1/201060.0050.0569200mg/l
11/1/2010102.0050.0651700mg/l
12/1/201082.5040.0705800mg/l
1/1/201157.5040.0710000mg/l
2/1/201154.0050.0716700mg/l
3/1/201162.5040.0697500mg/l
4/1/201192.0050.0750800mg/l
5/1/201166.0050.0690800mg/l
6/1/201150.0040.0636700mg/l
7/1/201150.0040.0624200mg/l
8/1/201150.0040.0617500mg/l
9/1/201150.0040.0596700mg/l
10/1/201150.0040.0526700mg/l
11/1/201152.5040.0504200mg/l
12/1/201150.0040.0504200mg/l
1/1/201252.0050.0507500mg/l
2/1/201257.5040.0520000mg/l
3/1/201270.0040.0553300mg/l
4/1/201250.0040.0553300mg/l
5/1/201250.0040.0549200mg/l
6/1/201250.0040.0549200mg/l
7/1/2012142.0050.0699200mg/l
8/1/2012110.0050.0786700mg/l
9/1/201286.0050.0813300mg/l
10/1/201266.0050.0840000mg/l
11/1/201275.0040.0881700mg/l
12/1/201262.5040.0902500mg/l
1/1/201354.0050.0755800mg/l
2/1/201350.0040.0655800mg/l
3/1/201376.0050.0639200mg/l
4/1/201355.0040.0620800mg/l
5/1/201350.0040.0579200mg/l
6/1/201354.0050.0565000mg/l
7/1/201398.0050.0638300mg/l
8/1/201374.0050.0678300mg/l
9/1/201358.0050.0648300mg/l
10/1/2013148.0050.0803300mg/l
11/1/201390.0050.0870000mg/l
12/1/201352.0050.0866700mg/l
Loading Chart...
Target
0.17 mg/l
Threshold
0.21 mg/l

Dissolved Oxygen

Units: mg/l Year
2013
Historical
period of record
High 8.00 11.90
Mean 6.11 6.5 1.13902
Low 4.70 1.60
No. of Samples 48 906

Five-year Trend Graph

     
1/1/20096.1546.1500000mg/l
2/1/20098.0847.1200000mg/l
3/1/20097.1347.1200000mg/l
4/1/20097.8847.3100000mg/l
5/1/20096.7547.2000000mg/l
6/1/20096.1047.0200000mg/l
7/1/20095.8546.9700000mg/l
8/1/20096.3546.6800000mg/l
9/1/20094.0346.1600000mg/l
10/1/20094.8545.6600000mg/l
11/1/20095.3345.4200000mg/l
12/1/20097.7345.6900000mg/l
1/1/20109.0846.2300000mg/l
2/1/20107.6046.4400000mg/l
3/1/20108.3047.1500000mg/l
4/1/20107.5047.5900000mg/l
5/1/20106.5047.7900000mg/l
6/1/20105.8847.4800000mg/l
7/1/20106.0546.9700000mg/l
8/1/20106.0546.7100000mg/l
9/1/20105.4546.2400000mg/l
10/1/20105.9845.9900000mg/l
11/1/20107.3046.1200000mg/l
12/1/20107.3546.3600000mg/l
1/1/20117.3346.5800000mg/l
2/1/20117.8846.8800000mg/l
3/1/20116.8547.1200000mg/l
4/1/20117.6047.3900000mg/l
5/1/20115.6547.1100000mg/l
6/1/20116.3546.9400000mg/l
7/1/20115.1546.5800000mg/l
8/1/20115.4046.1700000mg/l
9/1/20115.1345.8800000mg/l
10/1/20115.7545.5700000mg/l
11/1/20116.4345.7000000mg/l
12/1/20117.4345.8800000mg/l
1/1/20127.9346.3500000mg/l
2/1/20127.0046.6100000mg/l
3/1/20127.1346.9500000mg/l
4/1/20126.8347.1300000mg/l
5/1/20126.2347.0900000mg/l
6/1/20126.0346.8600000mg/l
7/1/20124.9046.3500000mg/l
8/1/20124.8846.0000000mg/l
9/1/20124.7045.6000000mg/l
10/1/20125.3045.3400000mg/l
11/1/20126.2845.3500000mg/l
12/1/20126.1545.3700000mg/l
1/1/20136.4545.6300000mg/l
2/1/20137.5346.0700000mg/l
3/1/20136.3846.3500000mg/l
4/1/20136.7846.6000000mg/l
5/1/20135.9046.5300000mg/l
6/1/20135.1546.3700000mg/l
7/1/20136.6046.3900000mg/l
8/1/20135.0845.9800000mg/l
9/1/20135.2345.7900000mg/l
10/1/20134.9045.4800000mg/l
11/1/20136.5845.5900000mg/l
12/1/20136.7545.8600000mg/l
Loading Chart...
Target
mg/l
Threshold
0.00 mg/l

Light Attenuation

Units: K(1/m) Year
2013
Historical
period of record
High 1.88 5.03
Mean 0.91 0.87 0.49938
Low 0.30 0.16
No. of Samples 48 747

Five-year Trend Graph

     
1/1/20090.9840.9800000K(1/m)
2/1/20090.7540.8700000K(1/m)
3/1/20090.6640.8000000K(1/m)
4/1/20091.0640.8600000K(1/m)
5/1/20090.6340.8200000K(1/m)
6/1/20090.5640.7700000K(1/m)
7/1/20090.8640.7500000K(1/m)
8/1/20090.7440.7500000K(1/m)
9/1/20090.8140.7800000K(1/m)
10/1/20090.8240.7400000K(1/m)
11/1/20091.2940.8500000K(1/m)
12/1/20090.8440.8900000K(1/m)
1/1/20100.7540.8800000K(1/m)
2/1/20101.0840.9300000K(1/m)
3/1/20100.8140.9300000K(1/m)
4/1/20101.2041.0000000K(1/m)
5/1/20100.7940.9100000K(1/m)
6/1/20100.7540.9000000K(1/m)
7/1/20100.8740.9200000K(1/m)
8/1/20100.6840.8500000K(1/m)
9/1/20101.2040.9200000K(1/m)
10/1/20101.0340.8900000K(1/m)
11/1/20100.8240.8900000K(1/m)
12/1/20101.1340.9600000K(1/m)
1/1/20110.2840.8600000K(1/m)
2/1/20110.7640.8700000K(1/m)
3/1/20110.7440.7900000K(1/m)
4/1/20111.2840.8400000K(1/m)
5/1/20110.5840.8000000K(1/m)
6/1/20110.3840.6700000K(1/m)
7/1/20110.4640.7000000K(1/m)
8/1/20110.6440.6800000K(1/m)
9/1/20111.1840.7500000K(1/m)
10/1/20111.0240.7100000K(1/m)
11/1/20110.8840.7600000K(1/m)
12/1/20110.7840.8300000K(1/m)
1/1/20120.8640.8900000K(1/m)
2/1/20121.0440.9600000K(1/m)
3/1/20120.8940.9100000K(1/m)
4/1/20120.5140.8300000K(1/m)
5/1/20120.4730.7600000K(1/m)
6/1/20120.5040.7100000K(1/m)
7/1/20121.1640.7600000K(1/m)
8/1/20121.1640.7800000K(1/m)
9/1/20121.2540.8400000K(1/m)
10/1/20121.0940.9400000K(1/m)
11/1/20120.8641.0000000K(1/m)
12/1/20120.7141.0400000K(1/m)
1/1/20130.7740.9700000K(1/m)
2/1/20130.9540.9400000K(1/m)
3/1/20130.5140.8200000K(1/m)
4/1/20130.6840.7500000K(1/m)
5/1/20130.6340.7100000K(1/m)
6/1/20130.5540.6800000K(1/m)
7/1/20131.4640.8000000K(1/m)
8/1/20130.9540.8000000K(1/m)
9/1/20131.2340.9200000K(1/m)
10/1/20131.4641.0500000K(1/m)
11/1/20130.9741.1000000K(1/m)
12/1/20130.7341.1300000K(1/m)
Loading Chart...
Target
K(1/m)
Threshold
0.00 K(1/m)

Rainfall

Units: inches/yr Year
2013
Historical
period of record
High 52.18 52.18
Mean 33.57 17.078760538706
Low 2.40
No. of Samples 359 4,615

Five-year Trend Graph

     
1/1/20090.92310.9200000inches
2/1/20090.57280.5700000inches
3/1/20091.18311.1800000inches
4/1/20091.86301.8600000inches
5/1/20094.04314.0400000inches
6/1/20094.30304.3000000inches
7/1/20094.02314.0200000inches
8/1/20093.37313.3700000inches
9/1/20096.94306.9400000inches
10/1/20091.68311.6800000inches
11/1/20096.39306.3900000inches
12/1/20095.04315.0400000inches
1/1/20103.18313.1800000inches
2/1/20102.12282.1200000inches
3/1/20106.80316.8000000inches
4/1/20105.27305.2700000inches
5/1/20100.52310.5200000inches
6/1/20103.59303.5900000inches
7/1/20105.95315.9500000inches
8/1/20109.08319.0800000inches
9/1/20103.35303.3500000inches
10/1/20100.00310.0000000inches
11/1/20100.57300.5700000inches
12/1/20101.00311.0000000inches
1/1/20112.33312.3300000inches
2/1/20110.48280.4800000inches
3/1/20119.66319.6600000inches
4/1/20110.88300.8800000inches
5/1/20112.95312.9500000inches
6/1/20113.32303.3200000inches
7/1/20116.56316.5600000inches
8/1/20118.23318.2300000inches
9/1/20115.03305.0300000inches
10/1/20111.23301.2300000inches
11/1/20111.94301.9400000inches
12/1/20110.21300.2100000inches
1/1/20120.69290.6900000inches
2/1/20120.76290.7600000inches
3/1/20121.56311.5600000inches
4/1/20121.59241.5900000inches
5/1/20122.77312.7700000inches
6/1/201215.993015.9900000inches
7/1/20126.92316.9200000inches
8/1/20129.11319.1100000inches
9/1/20126.08306.0800000inches
10/1/20123.59313.5900000inches
11/1/20120.17280.1700000inches
12/1/20122.29312.2900000inches
1/1/20130.37310.3700000inches
2/1/20131.17231.1700000inches
3/1/20131.48301.4800000inches
4/1/20133.58303.5800000inches
5/1/20131.97311.9700000inches
6/1/201312.093012.0900000inches
7/1/201311.063111.0600000inches
8/1/20138.85318.8500000inches
9/1/20139.93309.9300000inches
10/1/20130.81310.8100000inches
11/1/20130.73300.7300000inches
12/1/20130.14310.1400000inches
Loading Chart...
Target
inches/yr
Threshold
inches/yr

Salinity

Units: PSS Year
2013
Historical
period of record
High 36.00 39.30
Mean 31.31 33.24 4.19637
Low 18.30 5.70
No. of Samples 48 900

Five-year Trend Graph

     
1/1/200934.80434.8000000PSS
2/1/200935.65435.2300000PSS
3/1/200935.30435.2500000PSS
4/1/200935.65435.3500000PSS
5/1/200936.60435.6000000PSS
6/1/200936.28435.7100000PSS
7/1/200935.55435.8400000PSS
8/1/200936.13435.9200000PSS
9/1/200934.10435.7200000PSS
10/1/200934.48435.5200000PSS
11/1/200934.38435.1500000PSS
12/1/200931.50434.3600000PSS
1/1/201030.28433.4800000PSS
2/1/201031.28432.6700000PSS
3/1/201032.88432.4700000PSS
4/1/201029.55431.6500000PSS
5/1/201034.20431.6200000PSS
6/1/201035.15432.2200000PSS
7/1/201034.23432.8800000PSS
8/1/201033.20433.2000000PSS
9/1/201029.65432.6600000PSS
10/1/201032.48433.1500000PSS
11/1/201034.38433.1800000PSS
12/1/201033.90432.9700000PSS
1/1/201132.90432.7500000PSS
2/1/201131.98432.5500000PSS
3/1/201134.83433.4100000PSS
4/1/201129.80432.9700000PSS
5/1/201133.88432.8800000PSS
6/1/201135.68433.1800000PSS
7/1/201135.38433.5900000PSS
8/1/201135.63434.2000000PSS
9/1/201129.63433.3300000PSS
10/1/201133.88434.0100000PSS
11/1/201134.23434.0700000PSS
12/1/201133.45433.7000000PSS
1/1/201233.60433.4000000PSS
2/1/201234.15433.1600000PSS
3/1/201235.78434.1800000PSS
4/1/201236.95434.6900000PSS
5/1/201236.05435.0000000PSS
6/1/201235.13435.2800000PSS
7/1/201229.40434.5800000PSS
8/1/201228.65433.6600000PSS
9/1/201230.15432.7200000PSS
10/1/201229.70431.5100000PSS
11/1/201234.73431.2900000PSS
12/1/201234.05431.1100000PSS
1/1/201334.23431.9200000PSS
2/1/201334.38432.8700000PSS
3/1/201333.70433.4700000PSS
4/1/201333.95434.1700000PSS
5/1/201334.75434.1800000PSS
6/1/201335.70434.4500000PSS
7/1/201328.33433.4700000PSS
8/1/201330.18432.7700000PSS
9/1/201324.33431.2100000PSS
10/1/201322.68429.3300000PSS
11/1/201330.85428.6800000PSS
12/1/201332.70428.1800000PSS
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Turbidity

Units: NTU Year
2013
Historical
period of record
High 9.50 39.00
Mean 4.06 3.97 3.31303
Low 1.80 0.20
No. of Samples 59 833

Five-year Trend Graph

     
1/1/20093.7853.7800000NTU
2/1/20092.6843.2300000NTU
3/1/20092.1052.8500000NTU
4/1/200912.9055.3700000NTU
5/1/20091.7054.6300000NTU
6/1/20092.0054.1900000NTU
7/1/20092.8654.0400000NTU
8/1/20091.8853.9100000NTU
9/1/20091.4543.8000000NTU
10/1/20091.9451.9700000NTU
11/1/20095.3542.5800000NTU
12/1/20093.0052.7500000NTU
1/1/20105.7253.2200000NTU
2/1/201010.0544.5900000NTU
3/1/20105.0045.1800000NTU
4/1/20104.5655.6100000NTU
5/1/20104.1855.4200000NTU
6/1/20106.7046.0400000NTU
7/1/20102.9845.5800000NTU
8/1/20102.6344.3400000NTU
9/1/20102.5653.9400000NTU
10/1/20104.0653.8500000NTU
11/1/20104.5453.9100000NTU
12/1/20105.2253.6700000NTU
1/1/20112.8653.6500000NTU
2/1/20114.7053.9900000NTU
3/1/20114.1054.2500000NTU
4/1/201111.9055.5500000NTU
5/1/20112.8255.2700000NTU
6/1/20111.8854.7100000NTU
7/1/20112.6254.6700000NTU
8/1/20112.5254.3100000NTU
9/1/20114.4254.3600000NTU
10/1/20114.6653.1500000NTU
11/1/20114.5843.4500000NTU
12/1/20113.3853.7000000NTU
1/1/20124.1853.9600000NTU
2/1/20125.3654.4300000NTU
3/1/20128.4855.1100000NTU
4/1/20122.7454.7900000NTU
5/1/20121.7854.3200000NTU
6/1/20122.4054.1600000NTU
7/1/20123.5044.0400000NTU
8/1/20123.5053.7300000NTU
9/1/20123.2652.8600000NTU
10/1/20123.3652.9700000NTU
11/1/20125.2543.5500000NTU
12/1/20121.9843.4800000NTU
1/1/20132.5453.3200000NTU
2/1/20135.2853.6100000NTU
3/1/20133.1853.6000000NTU
4/1/20132.4543.4500000NTU
5/1/20136.7853.7000000NTU
6/1/20134.7854.1700000NTU
7/1/20133.5654.3400000NTU
8/1/20133.7854.0900000NTU
9/1/20133.4054.1300000NTU
10/1/20134.6854.5000000NTU
11/1/20134.9254.1900000NTU
12/1/20133.0453.9000000NTU
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Other Measures of Bay Health

In addition to nutrient levels and chlorophyll concentration, dissolved oxygen levels, and water clarity are also objective indicators of bay health. These have complex interactive cycles which are affected by rainfall, temperature, and tidal action, as well as other factors. High nutrient levels (nitrogen and phosphorus) can stimulate excessive growth of marine algae (indicated by chlorophyll a level), resulting in reduced water clarity (and increased light attenuation) and depleted oxygen levels. Both plants and animals in a bay need oxygen to survive, and the seagrasses which provide food and cover for bay creatures need light for photosynthesis.

Bay Contour Maps (2013)

Contour mapping is one of the best ways to visualize spatial differences in coastal water quality. The interactive map shown below presents monthly data for one selected water quality indicator atop an aerial view of the bay. Choose a different water quality parameter from the list at the top to change the map. Learn More about Water Quality Contour Mapping »

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Contour Visibility:

Visit the Water Quality Contour Mapping Tool to view and compare monthly water quality contour maps for ten different water quality indicators. In addition, you can generate your own custom maps.

Contour Legend:

  • Less than 1 mg/l
  • 1.0 - 5.9 mg/l
  • 6.0 - 10.9 mg/l
  • 11.0 - 17.9 mg/l
  • Greater than 18 mg/l

Seagrasses

Among the most important habitats in Florida's estuarine environments, seagrass beds are indispensable for the role they play in cycling nutrients, supplying food for wildlife, stabilizing sediments, and providing habitat for juvenile and adult finfish and shellfish. Use the interactive map below to observe the size, density and location of seagrass beds from year to year. The graph shows how the total amount of seagrass in the bay has changed over time. Learn More about Seagrasses »

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Target
447 acres

Land Use / Land Cover

Land use within a bay's watershed has a major effect on its water quality. In general, less development means better water quality. Land Cover/Land Use classifications categorize land in terms of its observed physical surface characteristics (upland or wetland, e.g.), and also reflect the types of activity that are taking place on it (agriculture, urban/built-up, utilities, etc.). Florida uses as its standard a set of statewide classifications which were developed by the Florida Department of Transportation. Learn More about Land Use and Land Cover »

Blackburn Bay is located within the Little Sarasota Bay Watershed. The chart below shows the land use / land cover characteristics for Little Sarasota Bay Watershed within the boundary of this Water Atlas. View details about the Little Sarasota Bay Watershed »

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