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Blackburn Bay Condition Report for 2012

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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 all water quality parameters below their associated target levels. However, the biotic indicator, seagrass, has continued to decrease.

Water quality: All three water quality indicators (chlorophyll a, nitrogen, and phosphorus) were rated as pass (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 (Numeric Nutrient Criteria Recommendations).The mean chlorophyll a level (5.1ug/l) in Blackburn Bay has decreased and was scored as excellent (scored as good in 2010), below the target (6.0ug/l) and threshold (8.2ug/l) levels. The mean nitrogen level (351.3ug/l) has slightly decreased and was scored as excellent, below the target (360.0ug/l) and threshold (430.0ug/l) levels. The mean phosphorus level (55.6ug/l) has remained constant and was also scored as excellent, below the target (170.0 ug/l) and threshold (210.0ug/l) levels.

Biotic Indicator:  The total acreage of seagrass has remained relatively constant since 1988 but in 2010 the mean level of seagrass (323 acres) was still below the target 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
2012
Historical
period of record
High 0.0208 0.043
Mean 0.0052 0.005 0.00493722 0.0060000000
Low 0.001 0.0002
No. of Samples 58 781

Five-year Trend Graph

     
1/1/20082.3640.0023600mg/l
2/1/20081.3740.0018700mg/l
3/1/20081.9440.0018900mg/l
4/1/20083.1140.0022000mg/l
5/1/20087.1440.0031800mg/l
6/1/20087.2840.0038700mg/l
7/1/20083.5440.0040600mg/l
8/1/20083.4350.0044100mg/l
9/1/200810.9640.0059100mg/l
10/1/20086.5840.0064900mg/l
11/1/20082.8440.0057700mg/l
12/1/20081.6440.0048300mg/l
1/1/20091.5450.0045000mg/l
2/1/20091.7650.0042200mg/l
3/1/20091.0350.0025700mg/l
4/1/20094.2450.0021800mg/l
5/1/20092.3450.0020900mg/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
Loading Chart...
Target
0.006 mg/l
Threshold
0.0082 mg/l
Good

Nitrogen, Total

Units: mg/l Year
2012
Historical
period of record
High 0.86 1.189
Mean 0.3602 0.16766201 0.3600000000
Low 0.125 0.055
No. of Samples 57 768

Five-year Trend Graph

     
1/1/2008260.0040.2600000mg/l
2/1/2008195.0040.2275000mg/l
3/1/2008200.5040.2185000mg/l
4/1/2008285.0040.2351300mg/l
5/1/2008372.5040.2626000mg/l
6/1/2008315.0040.2713300mg/l
7/1/2008345.0040.2855000mg/l
8/1/2008371.0050.3148300mg/l
9/1/2008534.0040.3704200mg/l
10/1/2008382.5040.3866700mg/l
11/1/2008397.5040.3908300mg/l
12/1/2008272.5040.3837500mg/l
1/1/2009269.0050.3710800mg/l
2/1/2009317.0050.3620800mg/l
3/1/2009323.0050.3269200mg/l
4/1/2009345.0050.3206700mg/l
5/1/2009267.5040.2990000mg/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
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
2012
Historical
period of record
High 0.20 0.53
Mean 0.0691 0.06947045 0.1700000000
Low 0.05 0.05
No. of Samples 53 752

Five-year Trend Graph

     
1/1/2008130.0040.1300000mg/l
2/1/2008115.0040.1225000mg/l
3/1/2008115.0040.1200000mg/l
4/1/2008150.0040.1275000mg/l
5/1/2008177.5040.1375000mg/l
6/1/2008127.5040.1358300mg/l
7/1/2008125.0040.1350000mg/l
8/1/2008140.0040.1391700mg/l
9/1/200882.5040.1337500mg/l
10/1/200860.0040.1187500mg/l
11/1/200865.0040.1000000mg/l
12/1/200865.0040.0895800mg/l
1/1/200968.0050.0800800mg/l
2/1/200962.5040.0671700mg/l
3/1/200980.0040.0667500mg/l
4/1/200987.5040.0713300mg/l
5/1/200950.0040.0688300mg/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
Loading Chart...
Target
0.17 mg/l
Threshold
0.21 mg/l

Dissolved Oxygen

Units: mg/l Year
2012
Historical
period of record
High 8.30 11.90
Mean 6.11 6.52 1.14791
Low 4.30 1.60
No. of Samples 48 858

Five-year Trend Graph

     
1/1/20087.1047.1000000mg/l
2/1/20086.8346.9700000mg/l
3/1/20086.6546.8600000mg/l
4/1/20086.2846.7200000mg/l
5/1/20086.3546.6400000mg/l
6/1/20086.4546.6100000mg/l
7/1/20084.8346.2300000mg/l
8/1/20084.5845.8600000mg/l
9/1/20084.8045.5500000mg/l
10/1/20085.2045.3700000mg/l
11/1/20086.6345.4200000mg/l
12/1/20087.0845.5200000mg/l
1/1/20096.1545.7400000mg/l
2/1/20098.0846.3200000mg/l
3/1/20097.1346.7100000mg/l
4/1/20097.8847.1600000mg/l
5/1/20096.7547.1800000mg/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
Loading Chart...
Target
mg/l
Threshold
0.00 mg/l

Light Attenuation

Units: K(1/m) Year
2012
Historical
period of record
High 1.49 5.03
Mean 0.88 0.86 0.50622
Low 0.32 0.16
No. of Samples 47 699

Five-year Trend Graph

     
1/1/20080.6240.6200000K(1/m)
2/1/20080.3940.5100000K(1/m)
3/1/20080.6540.5500000K(1/m)
4/1/20080.4940.5400000K(1/m)
5/1/20080.8840.6100000K(1/m)
6/1/20080.5440.6000000K(1/m)
7/1/20080.7040.6100000K(1/m)
8/1/20080.6640.6500000K(1/m)
9/1/20081.1840.7400000K(1/m)
10/1/20080.8840.8100000K(1/m)
11/1/20080.9440.8200000K(1/m)
12/1/20080.5740.8200000K(1/m)
1/1/20090.9840.8700000K(1/m)
2/1/20090.7540.8800000K(1/m)
3/1/20090.6640.8000000K(1/m)
4/1/20091.0640.8300000K(1/m)
5/1/20090.6340.7800000K(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)
Loading Chart...
Target
K(1/m)
Threshold
0.00 K(1/m)

Rainfall

Units: inches/yr Year
2012
Historical
period of record
High 51.52 52.18
Mean 33.57 17.078760538706
Low 2.40
No. of Samples 356 4,615

Five-year Trend Graph

     
1/1/20081.62311.6200000inches
2/1/20081.49291.4900000inches
3/1/20083.33313.3300000inches
4/1/20084.25304.2500000inches
5/1/20082.23312.2300000inches
6/1/20084.05304.0500000inches
7/1/20087.06317.0600000inches
8/1/20086.41316.4100000inches
9/1/20086.79306.7900000inches
10/1/20083.63313.6300000inches
11/1/20080.51300.5100000inches
12/1/20081.36311.3600000inches
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
Loading Chart...
Target
inches/yr
Threshold
inches/yr

Salinity

Units: PSS Year
2012
Historical
period of record
High 37.00 39.30
Mean 33.19 33.35 4.16034
Low 23.50 5.70
No. of Samples 48 852

Five-year Trend Graph

     
1/1/200835.48435.4800000PSS
2/1/200837.65436.5700000PSS
3/1/200836.50436.5400000PSS
4/1/200836.35436.5000000PSS
5/1/200836.68436.5300000PSS
6/1/200837.53436.7000000PSS
7/1/200835.53436.7100000PSS
8/1/200836.25436.4700000PSS
9/1/200830.60435.4900000PSS
10/1/200832.73434.8900000PSS
11/1/200835.55434.7000000PSS
12/1/200834.90434.2600000PSS
1/1/200934.80434.1400000PSS
2/1/200935.65434.0400000PSS
3/1/200935.30434.8200000PSS
4/1/200935.65435.3100000PSS
5/1/200936.60435.4800000PSS
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
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Turbidity

Units: NTU Year
2012
Historical
period of record
High 10.00 39.00
Mean 3.83 3.96 3.40621
Low 1.20 0.20
No. of Samples 57 774

Five-year Trend Graph

     
1/1/20082.2042.2000000NTU
2/1/20081.4841.8400000NTU
3/1/20082.1041.9300000NTU
4/1/20082.6042.1000000NTU
5/1/20084.4842.5700000NTU
6/1/20082.2542.5200000NTU
7/1/20081.4342.3900000NTU
8/1/20081.5252.4000000NTU
9/1/20083.5342.6400000NTU
10/1/20083.6042.8000000NTU
11/1/20083.4842.6400000NTU
12/1/20083.4042.8300000NTU
1/1/20093.7853.2200000NTU
2/1/20092.6843.4100000NTU
3/1/20092.1053.1700000NTU
4/1/200912.9054.7200000NTU
5/1/20091.7054.4300000NTU
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
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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 (2012)

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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