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September 15, 2006
PRP Executive Committee
C/O Lake Pontchartrain Basin Foundation
3838 North Causeway Blvd., Suite 2070
Metairie, Louisiana 70002
RE: Pontchartrain Restoration Program FY 2004 Annual Report
Dear PRP Executive Committee Members:
Enclosed is the Review Briefing Package for the Pontchartrain Restoration Program Year 3,
Fiscal Year 2004. The package contains the approved workplan, budget and executive
summary for the project entitled “Trends in the distribution and abundance of Lake
Pontchartrain benthic invertebrates with emphasis on clam habitat restoration”.
All work has been completed, as outlined in the approved workplan. Funds awarded have
been encumbered.
Thank you for providing the opportunity to contribute to the knowledge base needed to
restore Lake Pontchartrain. We look forward to a continued research partnership with the
Lake Pontchartrain Restoration Program.
Sincerely,
Dr. Michael A. Poirrier, Professor
Estuarine Research Laboratory
Department of Biological Services
University of New Orleans

PONTCHARTRAIN RESTORATION PROGRAM (PRP)
FY 2004 ANNUAL REPORT
APPROVED WORK PLAN, BUDGET & EXECUTIVE
SUMMARY
Title
Trends in the distribution and abundance of Lake Pontchartrain
benthic invertebrates with emphasis on clam habitat restoration
From
Michael A. Poirrier, Professor
Department of Biological Sciences
University of New Orleans
Lakefront
New Orleans, LA 70148
To
PRP Executive Committee
C/O Lake Pontchartrain Basin Foundation
3838 North Causeway Blvd., Suite 2070
Metairie, Louisiana 70002
Funding Agency: NOAA
Start Date: September 1, 2004
End Date: August 31, 2005
Report Date: September 15, 2006
Total Funding: $90,000.00

PONTCHARTRAIN RESTORATION PROGRAM (PRP)
FY 2004 ANNUAL REPORT
APPROVED WORK PLAN

SCOPE OF SERVICES
Background: Past studies of Lake Pontchartrain indicated a stressed benthic invertebrate
community. Causes of stress were believed to be shell dredging and toxic compounds in the
sediment. Recent studies indicate that recovery from shell dredging has occurred and that
sediment contamination is not a major problem, but that saltwater intrusion and episodic
hypoxia are serious problems. Unnaturally high salinity bottom water has entered Lake
Pontchartrain since the Mississippi River Gulf Outlet was completed in 1963. This saline
water produces stratification and bottom hypoxia. Low benthic invertebrate species diversity
and the absence of large (> 20 mm) Rangia cuneata clams from a 100 mi 2 north of the IHNC
documented in previous studies demonstrated a major impact. During the drought associated
with the La Niña climate pattern from 1998 to 2002, benthic invertebrate species diversity
and Rangia clam density decreased lake-wide from 374 to 4 clams/m 2 . This decrease in
species diversity and in Rangia abundance throughout the lake may have been due to
episodes of lake-wide low dissolved oxygen. Salinity has since returned to normal, but
Rangia clams have not recovered. Additional studies are needed during 2004 and 2005 to
obtain information needed to determine causal factors. These studies would provide
information on the effects of salinity shifts on the overall benthic community; possible
occurrence and effects of lake-wide hypoxia resulting from salinity stratification; the rate of
benthic invertebrate recovery, especially Rangia clams; and Rangia growth rates.
Goals: The long-term goal is to provide the knowledge needed to restore the benthic
community. Cases of decline and recovery need to be determined and natural variation
separated from human-induced changes. The working hypothesis is that saltwater intrusion is
the primary cause of stress, but additional data on the extent and degree of stress and benefits
of restoration are needed. Information on the effects of Mississippi River diversions is also
needed. The primary goal for 2004-2005 studies is to determine the cause of Rangia decline
and the rate of recovery.
Objectives: (1) Determine the status of the bottom biota of Lake Pontchartrain by
conducting lake-wide surveys of the distribution and abundance of benthic invertebrates
during 2004 and 2005. (2) Relate 2004-2005 data to historic data to determine status and
trends. This analysis will focus on the effects of hypoxia from salinity stratification, but will
also include possible changes due to spillway openings/leakage, shell dredging, toxic
chemicals, eutrophication, and shifts in overall ecosystem structure. (3) Determine changes
in the population dynamics of Rangia clams due to drought driven salinity changes and
recovery after a return to normal rainfall. (4) Based on benthic-invertebrate indicator species,
evaluate the current area affected by hypoxia from salinity stratification in 2004 and 2005
(100 mi 2 in 1999).
Project Methodology: Materials and methods employed in past UNO studies of Lake
Pontchartrain benthic invertebrates will be used in this study. Sites on established transects
will be sampled (three replicates) with a petite Ponar grab, sieved through a 0.6 mm screen
bucket, preserved in formalin with rose Bengal stain in the field, and sorted and identified in
the laboratory. Statistical analyses of data will include ANOVA and analyses in PRIMER
(Plymouth Routines in Multivariate Ecological Research). All comparisons of data sets,
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conclusions from data sets and hypothetical projections will be presented with appropriate
statistical measures, based on significance within the 95 % confidence interval.
Timeline and Milestones: During the 1 st Quarter (September through November), fall
transects will be conducted, samples processed, and data entered. A paper will be presented
at the ERCLA meeting. During the 2 nd Quarter (December through February), data entry will
be completed, statistical analyses performed, results compared to historic data to determine
trends and causal relationships, and a semiannual report will be prepared and submitted.
Spring transects will be completed, samples processed, and data entered during the 3 rd
Quarter (March through May). During the 4 th Quarter (June through August), data entry will
be completed and statistical analyses performed. A final report will be submitted by the end
of September 2005. Manuscripts for journal publication will be prepared and submitted.
Deliverables: Deliverables will include semiannual reports. Results will be made available in
the form of student theses, journal publications, meeting abstracts, poster and oral
presentations at regional and national conferences, and other reports.
Quality Control Measures: A QAPP is not required, but has been prepared for related work
funded through EPA. All work will employ appropriate instrument maintenance and
calibration, secure data management, trained personnel, control and replicate sampling and
statistical testing. Results will be submitted for publication in peer-reviewed academic
journals.
Techniques for assessing success. All comparisons of data sets, conclusions from data sets
and hypothetical projections will be presented with appropriate statistical measures, based on
significance within the 95 % confidence interval.
Personnel Qualifications: The University of New Orleans is an established research
university with laboratories, equipment, BS, MS, and PhD programs, and other resources for
conducting the proposed work. The P.I., Dr. Michael Poirrier, has thirty-three years of
experience as a research faculty member at UNO. He has authored, or coauthored 13 book
chapters, 47 journal articles, 28 technical reports, and 114 presentations at professional
meetings, and served as major professor for 28 graduate students. He has conducted research
on Lake Pontchartrain since 1969 and many of his publications pertain to Lake Pontchartrain
biota and water quality. He has managed large externally funded research projects throughout
his career. Dr. Poirrier participated in efforts to establish the Lake Pontchartrain Basin
Foundation and served on committees to draft the Lake Pontchartrain Basin Comprehensive
Management Plan. Elizabeth Spalding, a full time research associate, has a Masters degree in
Biological Sciences and over seven years of experience in environmental science. Carol
Franze, a research associate, will work half time on this project. She has an MA degree in
Geography with a specialty in environmental analysis and has conducted research in the
Pontchartrain Basin for over ten years.
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PONTCHARTRAIN RESTORATION PROGRAM (PRP)
FY 2003 ANNUAL REPORT
APPROVED BUDGET

APPROVED BUDGET
Category Amount Requested Match & Source
Personnel $ 71,550.00 $ 9,748.00 / UNO
Travel $ 2,000.00
Supplies $ 2,000.00
Indirect Cost (14%) $ 10,577.00 $25,248.00 / UNO
Equipment $ 3,873.00
Total $ 90,000.00 $34,996.00 / UNO
Justification:
Personnel: (1) Michael A. Poirrier, Principle Investigator - 1.5 months summer salary.
Funds are needed because his university appointment does not provide
summer support during this period of intense research effort.
(2) Elizabeth Spalding, Research Associate – 6 months support.
(3) Carol Franze, Research Associate – 9 months support.
Standard University fringe benefits at 21% of full-time salaries for Poirrier, Spalding and
Franze.
(4) Undergraduate Student Workers at $5 - $8 / hour.
Travel: Funds are requested to support local field travel and participation at a national
meeting. Local field travel will include vehicle mileage ($.32/mi) and boat gas and
maintenance.
Supplies: Funds are requested to purchase preservatives, reagents, glassware, microscope
slides, waters sample bottles, computer software and other item needed to conduct research.
Overhead: 14% of costs excluding equipment, as established by NOAA and UNO.
Equipment: Funds are requested to replace older field equipment which may cease to
function.
Matching funds represent Principle Investigator release-time for research, and the difference
between UNO standard Indirect/overhead Rate (42%) and the established rate by NOAA (14
BUDGET STATUS
All funds awarded have been encumbered.
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PONTCHARTRAIN RESTORATION PROGRAM (PRP)
FY 2003 ANNUAL REPORT
EXECUTIVE SUMMARY

RELEVANCE TO THE COMPREHENSIVE MANAGEMENT PLAN
The project supports monitoring, restoration and educational objectives of the Lake Pontchartrain
Basin Comprehensive Management Plan. Benthic invertebrates comprise a critically impaired
bottom habitat that is essential to the survival of fish, crabs, shrimp, and waterfowl. Rangia
cuneata can filter a volume of water equivalent to the volume of Lake Pontchartrain every 3-5
days, and through this feeding activity, reduce the impact of sewage, agriculture and storm water
runoff and Mississippi River diversions by processing phytoplankton, sediment, and bacteria.
Clams add almost a million ton of shells each year to the sediment. Dramatic improvements in
the environmental quality of Lake Pontchartrain should occur if the benthic community is
restored. In addition, benthic invertebrates serve as indicators of lake quality, especially the
deleterious effects of saltwater intrusion and the effects of restoration efforts. Finally, this project
educates university students at all levels, and results are presented to the public through diverse
media.
INTRODUCTION
Past studies of Lake Pontchartrain indicated a stressed benthic invertebrate community. Causes
of stress were believed to be shell dredging and toxic compounds in the sediment. Recent studies
indicate that recovery from shell dredging has occurred and that sediment contamination is not a
major problem, but that saltwater intrusion and episodic hypoxia are serious problems.
Unnaturally high salinity bottom water has entered Lake Pontchartrain since the Mississippi
River Gulf Outlet (MRGO) was completed in 1963. This saline water produces stratification and
bottom hypoxia. Low benthic invertebrate species diversity and the absence of large (> 21 mm)
Rangia cuneata clams from a 100 mi 2 north of the IHNC documented in previous studies
demonstrated a major impact. Hypoxic episodes are known to extend beyond this zone of
obvious impact and the area affected may be much larger.
During the La Niña climate pattern drought from 1998 to 2002, benthic invertebrate species
diversity increased with salinity and Rangia clam density decreased lake-wide from 374 to 4
clams/m 2 . The decrease in Rangia abundance may have been due to episodes of lake-wide low
dissolved oxygen. Salinity has since returned to normal, but Rangia clams have not recovered.
Additional studies have been conducted during 2004 and 2005 to obtain information needed to
determine causal factors. These studies provide information on the effects of salinity shifts on the
overall benthic community; possible occurrence and effects of lake-wide hypoxia resulting from
salinity stratification; and the rate of benthic invertebrate recovery, especially Rangia clams.
GOALS
The long-term goal is to provide the knowledge needed to restore the benthic community. Causes
of decline and recovery need to be determined and natural variation separated from humaninduced
changes. The working hypothesis is that saltwater intrusion is the primary cause of
stress, but additional data on the extent and degree of stress and benefits of restoration are
needed. Information on the effects of Mississippi River diversions is also needed. The primary
goal for 2004-2005 studies is to determine the cause of Rangia cuneata decline and the rate of
recovery.
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WORK COMPLETED
A lake-wide survey of benthic invertebrates and water quality parameters, such as salinity and
dissolved oxygen, was conducted during the fall of 2004 and spring of 2005. Samples were
processed and data analyzed. The condition of the benthic community in 2004-2005 was
evaluated and results compared to our long-term data set (1996–2004). Trends within the longterm
data set were analyzed using ANOVA, Primer, and ArcGis kriging analyses. Changes in the
populations of the large bivalves were determined and related to changes in water quality. The
area affected by detrimental low dissolved oxygen concentrations from salinity stratification was
evaluated based on species diversity values, community composition, and abundance of large
bivalves.
RESULTS
Water quality parameters, species diversity, number of Rangia cuneata, and biomass of clams
show a slow recovery after the drought. Salinity data from April 2004 to November 2005
indicate a return to typical spatial and seasonal changes. Salinity increased from west to east and
was higher in fall (ave. = 5.7 ppt) than spring (ave. = 4.3 ppt). Although slightly higher than the
Lake average of 4 ppt, these values differ from the high values (> 9 ppt) during the 1998-2001
drought from an El Niño climate shift. The return to a typical regime has resulted in a shift to a
community dominated by species adapted to lower salinity.
Species diversity values from 1996-2005 surveys for the west to east transect are presented in
Figure 1. Previous results showed increasing species diversity with increasing salinity due to the
drought. A slow return to typical species diversity values that increase from west to east with the
salinity gradient is apparent and expected. Species diversity values ranged from an average of
1.4 in the western portion of the lake to 2.3 in the eastern portion.
Associated with the drought was a lake-wide die-off of Rangia clams that occurred between July
2000 and April 2001. Numerous small clams (

MAJOR FINDINGS
· Water quality parameters, species diversity, number of Rangia cuneata, and biomass of
clams show a slow recovery after from the 2001 lake-wide die-off caused by stress from
low dissolved oxygen.
· Although number of clams has increased since the drought, the population in composed
of young, small clams, i.e. low biomass numbers.
· The primary source of stress that causes low species diversity and kills Rangia clams is
low dissolved oxygen from saltwater intrusion from the Mississippi River Gulf Outlet via
the Inner Harbor Navigation Canal as evidenced by the persistent, large “dead zone”.
Closure of the MRGO should alleviate this stress.
SIGNIFICANCE
This study documents the detrimental effects of saltwater intrusion from the Mississippi River
Gulf Outlet on benthic invertebrates in Lake Pontchartrain. It also provides information on the
effects of natural climate shifts on benthic community structure, resiliency of the Lake
Pontchartrain system, and recovery rates after major disturbance. In addition, this study provides
baseline data to evaluate the effects of Hurricane Katrina.
DELIVERABLES
· Poirrier, M.A. and E.A. Spalding. 2005. Special Report: The importance of Rangia cuneata
clam restoration to the holistic rehabilitation of the Lake Pontchartrain estuary. Submitted to
the Lake Pontchartrain Basin Foundation CMP Committee. 11 pgs.
· Poirrier, M.A. The importance of Rangia clams and submerged macrophytes to the holistic
restoration of Lake Pontchartrain. Environmental State of the State Conference, New
Orleans. October 2004
· Poirrier, M.A. and E.A. Spalding. The importance of Rangia cuneata clam restoration to the
holistic rehabilitation of Lake Pontchartrain. Seventh International Shellfish Restoration
Conference, Charlestown, S.C. November 2004.
· Poirrier, M.A. and E.A. Spalding. Environmental services provided by Rangia clams and the
benefits derived from the restoration of 250 km 2 of clam habitat in Lake Pontchartrain.
Benthic Ecology Meeting. March 2005, Williamsburg Virginia.
· Brammer, Amanda J., Ryan S. Poirrier and Michael A. Poirrier. Changes in the density of
Ischadium recurvum cased by a drought from an El Nino southern oscillation shift. Gulf
Estuarine Research Society Meeting. March 2005. Pensacola, Florida.
· Poirrier, Michael A. and Elizabeth Anne Spalding. The importance of Rangia clam
restoration to the holistic rehabilitation of the Lake Pontchartrain estuary. Coastal Restoration
and Enhancement through Science and Technology Meeting. April 2005. Lafayette,
Louisiana.
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4.0
3.5
3.0
Bonnet Carré
Spillway Opening
El Niño Drought
12
10
Species Diversity
2.5
2.0
1.5
1.0
8
6
4
0.5
0.0
Nov-96
Apr-97
Oct-97
May-98
Nov-98
Apr-99
Oct-99
May-00
Jul-00
Apr-01
Aug-02
Nov-03
Apr-04
Nov-04
Apr-05
Salinity (ppt)
EW1
EW2
EW3
EW4
EW5
Bottom
Salinity
2
0
Date Sampled
Figure 1. Species diversity values and average bottom salinity level of five west to east stations
across Lake Pontchartrain from 1996 – 2005 surveys.
Rangia cuneata per m 2
3000
2500
2000
1500
1000
500
0
41-45 mm
36-40 mm
31-35 mm
26-30 mm
21-25 mm
16-20 mm
11-15 mm
6-10 mm
< 5 mm
EW1 EW2 EW3 EW4 EW5 EW1 EW2 EW3 EW4 EW5
November 2004 April 2005
Figure 2. Density by size class of Rangia cuneata at five west to east stations across Lake
Pontchartrain in November 2004 and April 2005.
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