Status and Trends in the Virginia Tributaries and Main Stem: A Brief Overview of Procedures

and Results for 2009

Mike Lane (ODU) and

Rick Hoffman (VADEQ)

Current Status Assessments

• WQI –William et al., 2009

– Mean % Viol. Of Chl a, Secchi, DO Thresholds for each Segment

• P-IBI – Lacouture et al., 2006

– 3 Yr. Mean for each Station/Segment (Spring and Summer)

• B-IBI – Weisberg et al., 1997

– 3 Yr. Mean for each Station/Segment– % Area Degraded and Severely Degraded for each Stratum

Long Term Trend Assessments

• Water Quality (Well…. It’s complex)

– SK Trend Test: Secchi, DO, Chl a and TSS

– Blocked SK Trend Test: Tributary nutrients due to a method change in ’95

– Blocked SK Trend Test: Main Stem nutrients due to a method change in ‘88

– Blocked SK Trend Test: Main Stem TSS due to a lab change in ’96

– SK Trend Test: Elizabeth River except for segment ELIPH (DEQ segment)

– Analyses run by CBP segment, censored data, P value of 0.01.

• Living Resources

– SK Trend Test or Mann Kendall Trend (Benthos) P-IBI, B-IBI and component metrics

Additional Data/Analytical Resources

• Land-use Coverages from CBP Watershed Model.

• AFL and BFL NPDES Point Source TN/TP loads.

• USGS AFL total NPS N, P, TSS loads • USGS Fall-line RIMP trend analysis results

• Total AFL and BFL nutrient and sediment CBP Watershed Model loads estimates

Output Products

• Tabular output of specific status analyses

• Tabular summaries of all trend analyses: Excel data sets to DEQ/CBP, .pdf file tables

• Graphical summaries showing both status and trend results

• Scatterplots of all parameter/segment combinations analyzed

• Other supporting tables and figures ( Land-use, PS and NPS Loadings, etc.)

• Final deliverable is a detailed report describing all of the methods used, the results found and management implications

WQ Status and Trends in the York River

• WQI Status B or C upstream to D in all downstream segments

• Degrading trends in N and P in lower York and in lower Pamunkey and Mattaponi

•Improving N and P in Mobjack Bay

P-IBI Status and Trends York River

B-IBI Status and Trends York River

Benthic Status Probability-based Sampling

Stratum Marginal DegradedSeverely

DegradedTotal

Failing % Failing

James River 164 191 109 465 68.00%

York River 67 22 7 97 52.00%

Rappahannock River 119 104 45 268 72.00%

Virginia Bay Mainstem 330 0 330 659 16.00%

NPDES PS Nitrogen Loads

1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 20100.00E+0

2.00E+5

4.00E+5

6.00E+5

8.00E+5

1.00E+6

1.20E+6

1.40E+6

1.60E+6

BFL York River

Year

Annu

al T

N Lo

ads (

lb/y

r)

NPDES PS AFL and BFL Loads

USGS Fall-Line trends

Flow Adjusted Trend

Parameter Kendall τ P value LCI Slope UCI Significance

TN 0.1515 0.0006 6.7 16.4 26.9 Degrading

NO23 0.3147 <0.0001 21 37 55.1 Degrading

TP 0.6834 <0.0001 69.2 98.1 131.8 Degrading

DIP 0.4962 <0.0001 39.2 64.2 93.8 Degrading

TSS 0.6371 <0.0001 44.8 89.1 146.9 Degrading

Conclusions for 2009 – Regional Scale (VA)• Status results indicated:

– Poor or marginal water quality– Poor water clarity– Typically marginal living resources– Main Stem WQ and LR were generally better than the tributaries– Algal blooms common in lower Bay (increasing?)

• Trend results indicated:

– Few improvements in total AFL NPS N, P, or TSS Loads (except James R.) – Improving nutrient concentrations in some segments– Degrading trends in others– Degrading trends in water clarity– Few changes in Chl a or DO– No changes in the P-IBI + degrading trends in indicators– Few trends in the B-IBI or other benthic indicators– Nutrient “saturation” preventing improvements in plankton?– Benthic response stifled by lack of DO trends, regional contamination, etc.?

Conclusions for 2009 – Basin Scale

• James River

– Good WQ status upstream Marginal or Poor downstream– improving trends in nutrients AFL and in TF segments – Stable but mostly degraded LR throughout – Any improvements probably tied to improving trends AFL (loads and

conc.)

• Elizabeth River

– Poor WQ and LR status – Improving trends in nutrients and benthos– Poor status is related to high urbanization, high PS loads– Improving trends are probably related to reductions in PS nutrient

loads

Conclusions for 2009 – Basin Scale

• York River

– Poor WQ status and degrading trends in nutrients, TSS, clarity – Generally poor LR status with improvements in some segments– Upper York degrading trends tied to degrading conc. trends AFL– Lower York degrading trends in N appear tied to increasing PS Loads – Lower York degrading trends in P may be related to AFL total and/or BFL NPS P

loads

• Rappahannock River

– Poor WQ status with degrading trends in Chl a and DO – Poor LR status both P-IBI and B-IBI with no improvements– Degrading trends in Chl a and DO may be related to increases in AFL PS N loads

Needs and Schedule

• Better estimates of NPS Loads

• Some estimates of other nutrient inputs

• Other measures of management actions

• Land-use measures at the segment scale (historical?)

• Nutrient criteria for use with absolute status (Is Elgin funded?)

• All analytical results for 2010 should be done by the end of June (Quit laughing Rick!!!)

Last year’s Report for 2009:

Available at:www.odu.edu/vhosts/sci/chesapeakebay/reports/trends/2009.shtml

Reports are available as separate downloadable .pdf files for multiple years since before I can remember.

Appendices with endless arrays of tables and scatterplots ad nauseam in separate .pdf files all stuffed into an IZarc file. Whatever you do don’t print the whole thing….Please! We’re saving the Bay, not killing trees. Thanks!