DRAFT

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Prepared for:

The National Park Service Environmental Quality Division P.O. Box 25287 Denver, CO 80225-0287

and Submerged Aquatic Vegetation Technical Working Group

February 2012

DRAFT Deepwater Horizon/Mississippi Canyon 252 Oil Spill Report on Submerged Aquatic Vegetation Residing in Jean Lafitte National Historic Park and Preserve

Natural Resource Damage Assessment Spring and Fall 2011 Report

Prepared for:

The National Park Service Environmental Quality Division P.O. Box 25287 Denver, CO 80225-0287

and

Submerged Aquatic Vegetation Technical Working Group

Prepared by:

Weston Solutions, Inc. 2433 Impala Drive Carlsbad, California 92010

February 2012

MC 252 Oil Spill – Jean Lafitte National Historic Park and Preserve Submerged Aquatic Vegetation NRDA Spring 2011 Draft Report February 2012

TABLE OF CONTENTS

Executive Summary...... 5 1.0 INTRODUCTION ...... 6 1.1 Objective ...... 7 2.0 METHODS ...... 8 2.1 Station Locations ...... 9 2.2 Station Characterization ...... 13 2.2.1 GPS Locations ...... 13 2.2.2 Photographs...... 13 2.3 Physical Water Quality Assessment ...... 14 2.4 SAV Characterization ...... 15 2.4.1 SAV and FAV Assessment of Species Relative Abundance ...... 15 2.5 Chemistry Sampling ...... 16 2.5.1 Water Chemistry Sampling ...... 16 2.5.2 Sediment Chemistry ...... 16 2.6 Sample Collection Documentation ...... 17 2.6.1 Chemistry Sample Labeling and Documentation ...... 18 2.7 Sample Handling and Shipping ...... 18 2.8 Preservation/Holding Times ...... 18 2.9 Sample Analysis...... 18 2.10 Data Analysis ...... 19 2.10.1 Davis Pond Flow and Nutrient Load Assessment ...... 19 2.10.2 Watershed Flow Mapping ...... 19 2.10.3 Statistical Assessments of Survey Data ...... 19 3.0 RESULTS ...... 21 3.1 Mississippi River Flow and Nutrient Loading through Davis Pond Diversion .... 21 3.2 Water and Sediment Nutrients ...... 25 3.2.1 Water Nutrients ...... 25 3.2.2 Sediment Nutrients...... 26 3.3 Water Quality ...... 28 3.4 Submerged Aquatic Vegetation ...... 32 3.4.1 Submerged Aquatic Vegetation Diversity ...... 34 3.4.2 Submerged Aquatic Vegetation Distribution ...... 36 3.4.3 Change in SAV Diversity ...... 41 3.5 Floating Aquatic Vegetation ...... 43 3.5.1 Floating Aquatic Vegetation Percent Cover ...... 43 3.5.2 Floating Aquatic Vegetation Species Richness ...... 47 3.5.3 Salvinia molesta and Oxycaryum cubense ...... 48 3.5.4 Herbicide Usage ...... 54 4.0 Discussion ...... 55 4.1 Water Quality ...... 55 4.2 Submerged Aquatic Vegetation ...... 56 4.3 Floating Aquatic Vegetation ...... 58 4.4 Reference Area Assessment ...... 59

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4.5 Future Studies ...... 60 5.0 REFERENCES ...... 61

APPENDICES A JELA and Reference Station Photographs B Physical and Chemical Water Quality C Submerged and Floating Aquatic Vegetation

LIST OF TABLES

Table 2-1. Station Locations and Sampling Performed during Spring and Fall 2011 ...... 9 Table 3-1. Monthly Loads of Nitrogen (Nitrite + Nitrate) and Phosphorus (Total Phosphorus) entering JELA through the Davis Pond Diversion ...... 22 Table 3-2. Statistical Comparisons of Water Quality Parameters among Fall 2010, Spring 2011, and Fall 2011 Surveys ...... 28 Table 3-3. Statistical Comparisons of Water Quality Parameters between JELA and Reference Stations during Fall 2010, Spring 2011, and Fall 2011 Surveys ...... 30 Table 3-4. SAV Species Percent Occurrence at JELA and Reference Stations ...... 32 Table 3-5. Recent Reported Herbicide Application in the Vicinity of JELA ...... 54

LIST OF FIGURES

Figure 1-1. Jean Lafitte National Historical Park and Preserve Study Area and Stations ...... 7 Figure 2-1. Jean Lafitte National Historical Park and Preserve Study Area ...... 11 Figure 2-2. Bayou des Allemands and Humble Canal Reference Area ...... 12 Figure 2-3. Staffing Gauge at Bayou Coquille (A) and Garmin GPS (B) ...... 13 Figure 2-4. Water Quality Sampling using a YSI Data Sonde ...... 14 Figure 2-5. Long-handled Rake (A) and 0.25-m2 Quadrat (B) Used to Assess SAV and FAV...... 15 Figure 2-6. Sediment Collection Using a Ponar Grab Sampler ...... 16 Figure 2-7. Homogenized Sediment Sample for Nutrient Analysis ...... 17 Figure 3-1. Monthly Mississippi River Flow through the Davis Pond Diversion from January 2007 to December 2011 ...... 23 Figure 3-2. Average Monthly Mississippi River Flow through the Davis Pond Diversion Before (Jan-Apr), During (May-Aug), and After (Sep-Dec) Sustained Opening of the Diversion in 2010 ...... 23 Figure 3-3. Mississippi River Flow into JELA through the Davis Pond Diversion from May – August Periods of 2007-2009, 2010, and 2011 ...... 23 Figure 3-4. National Hydrology Database Map of Water Flow from the Davis Pond Diversion into JELA ...... 24 Figure 3-5. Average Total Nitrogen Concentrations in JELA and Reference Station Water Samples ...... 25 Figure 3-6. Average Total Phosphorus Concentrations in JELA and Reference Station Water Samples ...... 26

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Figure 3-7. Average Total Nitrogen Concentrations in JELA and Reference Station Sediment Samples ...... 27 Figure 3-8. Average Phosphorus Concentrations in JELA and Reference Station Sediment Samples ...... 27 Figure 3-9. Mean Water Quality Measurements in JELA and Reference Stations ...... 29 Figure 3-10. Total Chlorophyll Concentrations at JELA and Reference Stations during Spring 2011 and Fall 2011 Surveys ...... 31 Figure 3-11. SAV Occurrence at JELA Stations during 2006-2007, 2010, and 2011 Surveys ...... 33 Figure 3-12. SAV Occurrence at Reference Stations during 2010-2011 Surveys ...... 34 Figure 3-13. SAV Diversity at JELA and Reference Stations during Fall 2010 (A), Spring 2011 (B), and Fall 2011 (C) ...... 35 Figure 3-14. SAV Species Richness at JELA and Reference Stations ...... 36 Figure 3-15. Distribution of SAV Species at JELA and Reference Stations during the Fall 2010 Survey ...... 38 Figure 3-16. Distribution of SAV Species at JELA and Reference Stations during the Spring 2011 Survey...... 39 Figure 3-17. Distribution of SAV Species at JELA and Reference Stations during the Fall 2011 Survey ...... 40 Figure 3-18. Changes in SAV Species Diversity between Fall 2010 and Fall 2011 ...... 42 Figure 3-19. Floating Aquatic Vegetation Cover Observed in JELA and Reference Area Stations ...... 43 Figure 3-20. Percent Cover of Floating Aquatic Vegetation within JELA and the Reference Area during the Fall 2010 Survey ...... 44 Figure 3-21. Percent Cover of Floating Aquatic Vegetation within JELA and the Reference Area during the Spring 2011 Survey ...... 45 Figure 3-22. Percent Cover of Floating Aquatic Vegetation within JELA and the Reference Area during the Fall 2011 Survey ...... 46 Figure 3-23. Average FAV Species Richness at JELA and Reference Stations ...... 47 Figure 3-24. Comparison of Salvinia molesta Occurrence between Fall 2007 and 2010 Surveys ...... 49 Figure 3-25. Salvinia molesta Occurrence Across JELA and Reference Stations ...... 50 Figure 3-26. Percent Cover of Salvinia molesta during the Fall 2011 Survey ...... 51 Figure 3-27. Occurrence of Oxycaryum cubense during Fall 2011 ...... 52 Figure 3-28. Photographic Documentation of Surface Vegetation Changes at Three JELA Stations over Time ...... 53

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ABBREVIATIONS AND ACRONYMS

ANOVA Analysis of variance BACI Before after control impact DO Dissolved Oxygen FAV Floating Aquatic Vegetation GPS Global Positioning System ID Identification JELA Jean Lafitte National Historical Park and Preserve MC 252 Deepwater Horizon/Mississippi Canyon 252 NHD National hydrography dataset NOAA National Oceanic and Atmospheric Administration NRDA National Resource Damage Assessment P Phosphorus SAV Submerged Aquatic Vegetation TN Total Nitrogen TP Total Phosphorus USEPA U.S. Environmental Protection Agency USGS U.S. Geological Survey VOC Volatile Organic Compound WGS84 World geodetic system 1984

UNITS OF MEASURE

ºC degrees Celsius cm Centimeters ft3 cubic feet ft3/s cubic feet per second kg kilogram L Liter m meter m2 square meter mg/L milligram per liter mL Milliliter mS/cm milli-Siemens per centimeter NTU nephelometric turbidity unit oz ounce p, p-value Probability value ppt parts per thousand µg/L micrograms per liter m micrometer % parts per hundred, percent

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EXECUTIVE SUMMARY

In response to the Deepwater Horizon/Mississippi Canyon 252 (MC 252) Oil Spill, Mississippi River freshwater flows were diverted from the Davis Pond Diversion to Lake Cataouatche to reduce the potential for oil intrusion into the inland marshes, including Jean Lafitte National Historical Park and Preserve (JELA). As a result, the submerged aquatic vegetation (SAV) community at JELA may have been impacted by the increase in freshwater and nutrients into the interior marshes. Potential effects of increased freshwater and nutrients include diminished water quality and eutrophication. These changes in the physical habitat may result in reductions in the diversity and abundance of SAV species and proliferation of nuisance algal blooms (Harlin, 1995). Additionally, the loss of SAV and proliferation of dense floating aquatic vegetation (FAV) can result in habitat degradation and impacts to fish and wildlife (Poirrier et al., 2009).

The objective of the study was to assess the potential impacts of incremental increases in freshwater into JELA during the MC 252 Oil Spill. Surveys collected data on physical and chemical water quality parameters, sediment and water nutrient levels, and potential shifts in SAV community structure and/or floating aquatic species abundance as compared to reference stations, the Fall 2010 survey, and the 2006-2007 Poirrier et al. (2009) survey (i.e., baseline survey). These assessments allowed for a before-after comparison of the JELA SAV community to assess potential MC 252 response secondary impacts over time.

In response to the MC 252 Oil Spill, more than 70 billion cubic feet (ft3) of Mississippi River freshwater was released from the Davis Pond Diversion to Lake Cataouatche and JELA from May to August 2010, which was an increase of nearly 20 billion ft3 over the same period in 2009 and over 50 billion ft3 over the same period in 2011. Watershed assessments showed that flows from the Davis Pond Diversion reach both the lakeshores and interior canals of JELA. These sustained increases in flow resulted in reduced salinities in JELA as well as increased loads of nitrogen by 879 metric tons and phosphorus by nearly 200 metric tons into the downstream system leading to JELA throughout the summer and into the fall of 2010. Following these changes in physical habitat conditions, there have been notable changes in SAV community structure, including significant reductions in SAV diversity in JELA from an average of 3.83  0.24 species (mean  standard error) in Fall 2010 to 2.95  0.26 species in Spring 2011 (Friedman test, p = 0.002), while simultaneously SAV diversity at reference stations has significantly increased from 1.4  0.4 species to 3.0  0.55 species over the same period (p = 0.016). Additionally, there have been increases in the abundance of non-native SAV and FAV species, including highly invasive species such as Salvinia molesta and Oxycarium cubense. All of these factors provide evidence for the presence of response injuries.

Two follow-up field surveys are proposed in the spring and fall of 2012 to more fully determine if the loss of SAV diversity and increases in S. molesta and O. cubense abundance within JELA will persist, providing additional data required to assess the magnitude and duration of potential damages. Additionally, further studies are needed to determine the trajectory of recovery of the SAV community following the May-August 2010 period of increased flow of Mississippi River freshwater to JELA from the Davis Pond Diversion. By performing studies in the spring and fall, SAV community seasonal dynamics that are important to recovery, such as recruitment and re-growth, may be further assessed.

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1.0 INTRODUCTION

In response to the Deepwater Horizon/Mississippi Canyon 252 (MC 252) Oil Spill, Mississippi River freshwater flows were diverted from the Davis Pond Diversion to Lake Cataouatche to reduce the potential for oil intrusion into the inland marshes, including Jean Lafitte National Historical Park and Preserve (JELA) (Figure 1-1). As a result, the submerged aquatic vegetation (SAV) community at JELA may have been impacted by the increase in freshwater and nutrients into the interior marshes. Potential effects of increased freshwater and nutrients include diminished water quality and eutrophication. These changes in the physical habitat may result in reductions in the diversity and abundance of SAV species and proliferation of nuisance algal blooms (Harlin, 1995). Additionally, the loss of SAV and proliferation of dense floating aquatic vegetation (FAV) can result in habitat degradation and impacts to fish and wildlife (Poirrier et al., 2009).

SAV communities are known to be sensitive to slight changes in physical water quality conditions (Davis and Brinson, 1980; Dennison et al., 1993). Sustained changes in salinity can alter SAV community composition since salinity tolerances are highly species specific (Poirrier et al., 2010). Consequently, salinity is considered to be the primary factor that controls SAV community structure in coastal Louisiana (Cho and Poirrier, 2005). Additionally, increases in turbidity and associated reductions in light penetration within the water column can favor floating aquatic plants as well as surface-mat forming species of SAV, which can lead to the competitive exclusion of species that recruit opportunistically (Poirrier et al., 2009).

Previous studies have shown that increased nutrients to lakes result in reductions in SAV due to increased density and abundance of phytoplankton and algal epiphytes (Kalff, 2002). In lakes, shifts from SAV-dominated communities to phytoplankton-dominated communities can occur with nutrient addition (Dodson et al., 2005). Similarly, in marine and estuarine communities, SAV is replaced by macroalgae with nutrient addition (Day et al., 1989). One means of controlling unwanted SAV in warm-water farm ponds is to add fertilizer to produce algal blooms in early spring that shade new SAV growth from the bottom (Poirrier, personal communication). Based on fundamental SAV ecology, high loading of nitrogen and phosphorus from the increased Mississippi River flow through the Davis Pond Diversion has the potential to adversely affect the SAV community in JELA.

Aquatic habitats throughout JELA were surveyed from June 2006 through April 2008 by Poirrier et al. (2010) to determine the community composition, distribution, and abundance of SAV. The waters within JELA were found to range from freshwater to low-salinity, brackish-water, and supported ten SAV species within ponds, canals, and Lake Cataouatche. Seven of the ten species were determined to be native species: Cabomba caroliniana, Ceratophyllum demersum, Heteranthera dubia, Najas guadalupensis, Potamogeton pusillus, Vallisneria americana, and Zannichellia palustris, while the remaining three species were categorized as exotic: Egeria densa, Hydrilla verticillata, and Myriophyllum spicatum. The Poirrier et al. study provided a baseline assessment of the JELA SAV community prior to the increased diversion of Mississippi River water into JELA as a response to the MC 252 Oil Spill. By performing a similar study of the JELA SAV community using methods that are consistent with the prior Poirrier et al. study, potential impacts of the sustained diversion of Mississippi River freshwater in JELA can be assessed.

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1.1 Objective

The objective of the study was to assess the potential impacts of incremental increases in freshwater into JELA during the MC 252 Oil Spill. An initial field survey was performed in September 2010 (Fall 2010 survey) that collected SAV community structure and water quality data. Two follow-up field surveys were performed in the spring and fall of 2011 to evaluate the extent and magnitude of any potential changes within the SAV community that may have occurred following the increased freshwater flow to JELA during the oil spill response. Additionally, spring and fall 2011 surveys were performed to determine if seasonally distinct changes to water quality, floating aquatic vegetation, and the SAV community within JELA were evident. Surveys collected data on physical and chemical water quality parameters, sediment and water nutrient levels, and potential shifts in SAV community structure and/or floating aquatic species abundance as compared to reference stations, the Fall 2010 survey, and the 2006- 2007 Poirrier et al. (2009) survey. These assessments allowed for a before-after comparison of the JELA SAV community to assess potential secondary impacts of MC 252 response over time.

Figure 1-1. Jean Lafitte National Historical Park and Preserve Study Area and Stations

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2.0 METHODS

The methods discussed in this report pertain specifically to the surveys performed during spring and fall 2011, which included three additional JELA stations than were surveyed in fall 2010 as well as more detailed assessments of the SAV and FAV communities (e.g., ephiphyte cover, SAV cover, and FAV species), measurements of nutrient concentrations at 14 stations rather than ten, and chlorophyll a concentrations in the water column. Methods used during the Fall 2010 survey were detailed in the draft report entitled “Deepwater Horizon/Mississippi Canyon 252 Oil Spill Report on Submerged Aquatic Vegetation Residing in Jean Lafitte National Historic Park and Preserve, Natural Resource Damage Assessment” (Weston, 2011).

Field surveys were conducted within JELA and at a reference area outside of JELA during September 7 through 11, 2010 (Fall 2010), May 16 through 21, 2011 (Spring 2011), and September 12 through 17, 2011 (Fall 2011). Surveys included assessments of SAV species composition at 36 stations (Fall 2010) and 39 stations (Spring and Fall 2011) within the northeast portion of the Barataria Estuary in JELA and at five reference stations positioned within Bayou des Allemands and Humble Canal north of the Davis Pond Diversion in areas that were not subjected to increased freshwater intrusion (Figure 1-1). 33 of the 39 JELA stations in the Spring and Fall 2011 surveys were the same locations assessed in the Fall 2010 survey. Three stations from the 2010 survey were re-located and three new stations were added within JELA to better assess a potential nutrient gradient along Bayou Segnette and to investigate areas that were not well represented in the previous survey. The initial determination of the number of stations to be surveyed within JELA as part of this study was based on the U.S. Environmental Protection Agency’s (USEPA’s) Guidance for the Data Quality Objectives Process (USEPA, 2006a) and Data Quality Assessment: Statistical Methods for Practitioners (USEPA, 2006b).

Determinations of the relative abundance and distribution of native, exotic, and nuisance SAV, as well as macroalgae, FAV, and emergent aquatic plants, were performed at all stations using methods consistent with the JELA baseline Poirrier et al. study (2009). Physical water quality parameters were also measured at all JELA stations. Surface water and surface sediment samples were collected at 14 of the 39 JELA stations and at all five of the reference stations for nutrients analysis (total nitrogen [TN] and total phosphorus [TP]). Water samples were also collected at all 39 JELA stations and at all 5 reference stations for chlorophyll a analysis.

Shallow-draft vessels (airboats, mud boats, and pontoon boats) that could access stations throughout JELA were used to perform the SAV surveys. The field crew consisted of five to six personnel over the five-day sampling period, including Dr. Hyun Jung Cho– a field lead familiar with the SAV survey protocols and local species (Spring 2011); Dr. Mike Poirrier– expert in SAV identification and SAV survey protocols (Fall 2010 and 2011); Brian Riley and Dan McCoy – field scientists with experience in SAV surveys, water quality sampling, and water and sediment sampling; Dusty Pate and Julie Whitbeck – National Park Service ecologists familiar with JELA; and a responsible party representative.

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2.1 Station Locations

A total of 39 JELA stations and five reference stations were sampled in the Spring 2011 and Fall 2011 surveys (Table 2-1, Figure 2-1 and Figure 2-2). Sample stations were defined to be areas of approximately 100 square meters (m2) located along the shorelines of lakes, canals, and bayous within JELA that had been known to contain SAV in previous surveys. The JELA stations were located in the northeast portion of Barataria Bay and were selected to correspond with stations used in the Fall 2010 and 2006-2007 Poirrier et al. studies. All of the sampling stations were located in areas of JELA that have been previously found to support SAV, including the lake shorelines and inland marsh areas. Reference stations were located approximately 17 miles west of JELA along Humble Canal and Bayou des Allemands in an area that was not subjected to increased flow from the Mississippi River through the Davis Pond Diversion.

Table 2-1. Station Locations and Sampling Performed during Spring and Fall 2011 SAV Water and Distribution Physical Sediment and Relative Photo and GPS Station Water Body Latitude Longitude Water Nutrient Abundance Documentation Quality Chemistry of Floating Aquatics 1 Bayou Segnette 29.86354 -90.16579 X X X X 2 Tarpaper Canal 29.83478 -90.15471 X X X X 3 Parallel Canal 29.82387 -90.12334 X X X X 4 Pipeline Canal 29.77156 -90.14011 X X X X Lower Kenta 5 29.77386 -90.11121 X X X X Canal 6 Bayou Segnette 29.74235 -90.14192 X X X X Lake Salvador 7 29.79624 -90.16225 X X X X Shoreline Lake Salvador 8 29.84078 -90.16879 X X X Shoreline Bayou 9 29.81842 -90.16361 X X X X Bardeaux Lake 10 Cataouatche 29.84347 -90.19173 X X X X Shoreline Horseshoe 11 29.84435 -90.14758 X X X Canal Horseshoe 12 29.84779 -90.14344 X X X Canal 13 Bayou Boeuf 29.84396 -90.15648 X X X X 14 Pipeline Canal 29.81379 -90.12727 X X X 15 Pipeline Canal 29.78842 -90.13806 X X X X Bayou Aux 16 29.78867 -90.07484 X X X Carpes Bayou Aux 17 29.77729 -90.07274 X X X Carpes Lower Kenta 18 29.76842 -90.10723 X X X Canal 19 Pipeline Canal 29.78685 -90.13630 X X X Bayou Aux 20 29.78616 -90.08916 X X X Carpes 21 Lake Salvador 29.75726 -90.15395 X X X

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SAV Water and Distribution Physical Sediment and Relative Photo and GPS Station Water Body Latitude Longitude Water Nutrient Abundance Documentation Quality Chemistry of Floating Aquatics Shoreline Lake 22 Cataouatche 29.86864 -90.23616 X X X X Shoreline Lake 23 Cataouatche 29.86177 -90.21815 X X X Shoreline Lake 24 Cataouatche 29.83181 -90.18126 X X X Shoreline 25 Twin Canals 29.80824 -90.12653 X X X 26 Bayou Segnette 29.84264 -90.17279 X X X Lake Salvador 27 29.74563 -90.15242 X X X Shoreline 28 Bayou Segnette 29.80524 -90.15745 X X X 29 Bayou Segnette 29.78042 -90.14998 X X X X 30 Bayou Segnette 29.76067 -90.14577 X X X 31 Bayou Segnette 29.83230 -90.16580 X X X 32 Lake Salvador 29.80437 -90.18497 X X X Bayou 33 29.81695 -90.17032 X X X Bardeaux 34 Tarpaper Canal 29.83380 -90.15257 X X X 35 Yankee Pond 29.85024 -90.17355 X X X Lake 36 Cataouatche 29.84249 -90.18963 X X X Shoreline 37 Tarpaper Canal 29.82749 -90.13341 X X X 38 Whiskey Canal 29.86320 -90.18632 X X X 39 Bayou Segnette 29.82414 -90.16322 X X X X R1 Humble Canal 29.85938 -90.47208 X X X X Bayou des R2 29.85766 -90.48676 X X X X Allemands Bayou des R3 29.84702 -90.48392 X X X X Allemands R4 Humble Canal 29.86501 -90.46887 X X X X R5 Humble Canal 29.85661 -90.46104 X X X X

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Figure 2-1. Jean Lafitte National Historical Park and Preserve Study Area

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MC 252 Oil Spill – Jean Lafitte National Historic Park and Preserve Submerged Aquatic Vegetation NRDA Spring 2011 Draft Report February 2012

Figure 2-2. Bayou des Allemands and Humble Canal Reference Area

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2.2 Station Characterization

The field crew performed station assessments consistent with National Resource Damage Assessment (NRDA) protocols. A global positioning system (GPS) unit recorded the latitude and longitude of stations and photographs were taken to record the general habitat characteristics of each station. Physical water quality and SAV community assessments were performed at all stations, while water and sediment samples were collected for nutrient analysis at a subset of the stations.

2.2.1 GPS Locations

Stations were positioned as close as possible to their preselected GPS locations. During the Spring and Fall 2011 surveys, all stations were able to be sampled at their pre-selected locations. The station name (general geographic location or established sampling area) along with latitude and longitude obtained via a handheld GPS were noted. Coordinates were recorded in decimal degrees with World geodetic system 1984 (WGS84) as the datum and each station was recorded as a waypoint with the GPS unit. Photographs were taken of the GPS unit, with the date and time visible, at each station in accordance with NRDA protocol (Figure 2-3A). At several stations during the Spring 2011 survey, it was evident that an herbicide had been applied to the floating aquatic vegetation in the recent past. This was noted on the datasheets.

2.2.2 Photographs

Photographs were taken of each station to record A B existing conditions at the time of the assessment. Photographs were taken in a series throughout each day so that they could later be sequentially associated with the corresponding sampling locations (e.g., through use of GPS Photolink software or by keeping a detailed photo log) per the NRDA Field Photography Guidance document. No pictures were Figure 2-3. Staffing Gauge at Bayou Coquille (A) and deleted or altered in Garmin GPS (B) accordance with NRDA protocols. Once a day, a photograph of the staff gauge at Bayou Coquille was taken to document the water level within JELA (Figure 2-3B).

At the conclusion of the study, all photographs were logged into the National Oceanic and Atmospheric Administration (NOAA) NRDA Trustees Sampler Photo Logger Form. Original

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photo files were uploaded to a computer hard drive and not opened. The original photo files were ultimately relinquished to NRDA personnel with all required Chain of Custody forms.

2.3 Physical Water Quality Assessment

Following initial assessment of the station to establish the presence of SAV and completion of the Site Characterization Form, the field crew performed physical water chemistry measurements for pH, dissolved oxygen (DO), temperature, salinity, conductivity, water depth, turbidity, light penetration (using a Secchi depth), and light irradiance above and below the water’s surface (using a light meter). Water quality assessments were completed upon arrival at the site to avoid suspension of sediments within the water column from other assessment activities.

Light penetration was measured using a Secchi disk, a round black and white weighted disk that was lowered through the water until the distinction between white and black quadrants was no longer visible to the human eye. The disk was attached to a non-stretching rope, marked at 10-cm intervals. The disk was lowered slowly over the side of the boat facing the sun and not in the shadow of the vessel, until the disk disappeared; it was then raised until it reappeared. The depth at which the disk reappeared was recorded onto a field sheet. At the time of the measurement, the time of day and cloud cover were also recorded. Secchi depth provides a measure of the light-limited colonization depth of SAV species (Poirrier et al., 2009) because transparency readings approximately equate to 10% of surface light (Wetzel, 2001).

Light attenuation was measured using a Li-Cor spherical quantum sensor (model LI-193) for in-water measurements and a Li-Cor quantum sensor (model Figure 2-4. Water Quality Sampling LI-190) for in-air measurements. The sensor was using a YSI Data Sonde lowered into the water column to obtain a profile of light readings. Sub-surface light readings were taken just below the water surface and at three additional depths (1/3 depth, 2/3 depth, and bottom depth). The average light reading over a 15- second interval (averaged internally by the light meter) was recorded onto data sheets for all in- air and in-water measurements. At the time of the measurement, the time of day and cloud cover were recorded. Whenever possible, measurements were taken during clear skies.

Water quality measurements for DO, pH, turbidity, temperature, conductivity, and salinity were measured using a pre-calibrated YSI 6920 data sonde (Figure 2-4). At each station, the sonde was lowered approximately two feet below the water’s surface and allowed to equilibrate. Dissolved oxygen was recorded in milligrams per liter (mg/L), turbidity was recorded in nephelometric turbidity units (NTU), salinity was recorded in parts per thousand (ppt), conductance was recorded in milli-Siemens per centimeter (mS/cm), pH was measured in pH

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units, and temperature was recorded in degrees Celsius (ºC). All values were recorded onto SAV Site Characterization data sheets.

2.4 SAV Characterization

Characterization of SAV began with an initial visual assessment of presence of SAV, FAV, and emergent plant species at each station (Figure 2-5). SAV characterizations were performed within three quadrats at each station, typically located along the shoreline. The 10-m2 quadrats consisted of the area immediately surrounding the boat (1 m x 5 m on either side of the boat). Water depth was measured within each 10-m2 quadrat.

2.4.1 SAV and FAV Assessment of Species Relative Abundance

The boat was moved four times within each 100-m2 station to obtain four replicate 10-m2 SAV survey areas. SAV species composition was determined by direct observation of species present within the 10-m2 SAV survey areas and by using a long-handled rake to collect SAV growing below the depth at which species could be clearly seen. FAV species within the 10-m2 quadrats were also recorded. The percent coverage of SAV, A B FAV, and two species of invasive FAV (Salvinia molesta and Oxycarium cubense) were estimated within each 10-m2 quadrat.

Any flowering shoots observed on SAV were

recorded onto field data 2 forms and digital Figure 2-5. Long-handled Rake (A) and 0.25-m Quadrat (B) photographs were taken to Used to Assess SAV and FAV

document observed SAV, FAV, and emergent species.

SAV leaves were examined for the presence of epiphytes. Epiphytes were characterized into five categories: A) no filamentous algae present; B) filamentous algae covers up to 25% of leaves; C) filamentous algae covers between 25% and 50% of leaves; D) filamentous algae covers between 50% and 75% of leaves; and E) filamentous algae covers greater than 75% of leaves.

Quadrat Assessments Percent coverage of floating plants, emergent plants, and surface algae were also estimated at each station using randomly tossed 0.25-m2 quadrats within each of the 10-m2 replicate SAV survey areas. In instances where SAV could not be seen due to murky water or overlying FAV, percent coverage within the 0.25-m2 quadrat was estimated by raking within the quadrat.

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2.5 Chemistry Sampling

Water and sediment nutrient chemistry samples were collected from the 14 targeted JELA stations and five reference stations, and chlorophyll a samples were collected from all 39 JELA stations and all five reference stations. Sampling of water and sediment followed established procedures provided by the SAV Technical Working Group in the Mississippi Canyon 252 Incident SAV Tier 1 Pre-Assessment Plan Pre-Impact Baseline Characterization and described in the approved Sampling and Analysis Plan.

2.5.1 Water Chemistry Sampling

Water nutrient samples were collected at each station by lowering a laboratory-certified clean, 1- liter, polyethylene bottle below the surface of the water and allowing the water to flow directly into the sample container. The sample bottles were filled to approximately 90 percent of capacity, to allow for ample headspace during cold storage. Chlorophyll a samples were collected in the same fashion as the water nutrient samples using 500 milliliter (mL) laboratory- certified clean sampling containers. Sample identification (ID) labels were affixed to each container and covered with clear tape wrapped around the entire container circumference. Following labeling, sample containers were immediately placed inside a cooler on ice.

Chlorophyll a samples were stored on ice in the field and later filtered at the end of each day. Chlorophyll a samples were poured through a 0.45 micrometer (m) glass filter attached to a clean Buchner funnel. Filtered volumes of sample water varied from 100 mL to 200 mL depending upon the amount of residue retained on the filter paper after 100 mL had been filtered for a given station (a minimal amount of coloration on the filter paper was recommended). Additional water was filtered if the filter paper appeared to have only a light coloration. Following filtration, the filter paper was removed from the Buchner funnel, placed into a labeled Ziploc bag, and frozen.

2.5.2 Sediment Chemistry

A ponar grab sampler was used to collect sediment samples from each of the 14 targeted sampling stations in JELA and from the five reference stations. The ponar grab sampler and stainless steel mixing bowl and spoon were decontaminated prior to use at each of the sampling stations using laboratory-grade detergent (Alconox), followed by rinsing with site water. The ponar grab sampler was lowered to the sediment at a controlled speed of approximately 1 foot per second to minimize disturbance of any flocculent material on the sediment surface. Only the weight of the sampler was used to penetrate the sediment. The ponar grab sampler was inspected upon retrieval to ensure the sampler was not overfilled and that the sediment surface was not Figure 2-6. Sediment Collection pressed against the sampler top. Grab samples were Using a Ponar Grab Sampler

deemed to be acceptable if overlying water was present, indicating minimal leakage and retention of flocculent material; sediment surface was

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undisturbed, indicating lack of channeling or sample washout; and the desired penetration depth was achieved (e.g., 4-5 centimeters [cm] for a 2-cm sample).

Overlying water was drained from the sampler until the sediment was exposed. Special attention was paid while draining water to ensure retention of any surface flocculence. Once the overlying water was drained from the sample, a stainless steel spoon was used to collect the top 2-cm layer into a stainless steel mixing bowl (Figure 2-6). Sediments in direct contact with the sides or top of the sampler were avoided. Sediment was homogenized in the mixing bowl using the stainless steel spoon (Figure 2-7) and subsequently transferred into appropriate containers (8-ounce Figure 2-7. Homogenized Sediment glass jars with Teflon lids) for sediment nutrient Sample for Nutrient Analysis and sediment chemistry analyses and Ziploc bags for grain size analyses). Sediment samples were labeled and immediately placed into a cooler and kept on ice. Samples were delivered to Sample Intake personnel within five days of collection.

2.6 Sample Collection Documentation

Sample collection documentation was performed in accordance with the instructions in the NOAA Field Sampling Workbooks (available on the case’s file transfer protocol site). Sample IDs were listed under each category of sample types. If no samples of a given type were taken, “none was entered. Sample labels were prepared following the sample ID protocol provided in the instructions from the trustee data management team and contained the following information:

 Location code (e.g., LAAN38 for Louisiana grid section 38)  Letter indicating the study year that the sample was collected (e.g., A for the first year, B will be the second year, etc.)  Month and day of collection (e.g., 0516 for May 16)  Matrix (e.g., W or S for water or sediment)  Team number (e.g. 41) and the sample number (e.g., 03 if it was the third station sampled); thus,  A water sample taken on May 19 as the 4th sample collected that day was labeled “LAAN38-B0519-W4104.”

Sample ID labels were affixed to each container and covered with clear tape wrapped around the entire container circumference. Tape was also applied to secure the container lid. The collection of samples was recorded in both the SAV Site Characterization Form and in the NRDA Sample Collection Form for Soils and Sediments. All original field notebooks, forms, and notes, were preserved, signed, and dated by the field lead. If incorrect entry occurred, the original entry was crossed out, dated, and initialed. All original records were gathered and kept on file by the trustees.

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2.6.1 Chemistry Sample Labeling and Documentation

Sample labels were filled out in accordance with the sample ID protocol provided in the instructions from the trustee data management team. Sample ID labels were affixed to each container and covered with clear tape that was wrapped around the entire container circumference to ensure the label remained affixed to the sample container. Sample container lids were also taped as a security measure to insure against loss of sample due to a lid becoming loose. The collection of each sample was noted both in the SAV Site Characterization Form and in the NRDA Sample Collection Form for Soils and Sediments. All original field notebooks, forms, and notes that were part of the study were signed and dated, and original copies were relinquished to the trustees. If entries were crossed out or corrected for any reason, the data logger initialed and dated the changes.

2.7 Sample Handling and Shipping

All collected samples were transferred to the NRDA Sample Intake Team. Transfer of samples to the Sample Intake Team occurred after the initial two days of field work and on the day following the last field sampling event. Field sampling crews followed NRDA protocol documents for specific sample shipping and notification/sampling documentation instructions.

2.8 Preservation/Holding Times

All chemistry samples were immediately placed into coolers following sample collection and kept at 4°C. Samples were transferred to the Sample Intake Team following the completion of field sampling to be frozen as soon as possible (for sediment and tissue chemistry samples). Water and sediment nutrient samples and chlorophyll a filter samples were analyzed within their appropriate holding times.

Additional details on sample storage and holding times are available in the Analytical Quality Assurance Plan for the MS Canyon 252 (Deepwater Horizon) Natural Resource Damage Assessment.

2.9 Sample Analysis

Chemical analysis of water and sediment nutrients concentrations were performed by the University of Maryland System Chesapeake Biological Laboratory. TN (organic nitrogen + ammonium + nitrate + nitrite) in water was measured by U.S. Geological Survey (USGS) method I-2650-03, and TP (all forms) in water was measured by USGS method I-4650-03, which involved alkaline persulfate digestion (Patton and Kryskalla, 2003). Sediment N was measured using an elemental analyzer following USEPA method 440.0 (Zimmerman et al., 1997). Sediment P was measured using high temperature hydrochloric acid extraction (Aspila et al., 1976). Chlorophyll a analysis of filtered water samples was also performed by the University of

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Maryland System Chesapeake Biological Laboratory. Chlorophyll a was analyzed according to USEPA Method 445.0

2.10 Data Analysis

2.10.1 Davis Pond Flow and Nutrient Load Assessment

Flow data for the Davis Pond Diversion near Boutte, LA between February 2006 and September 2011 was obtained from the USGS Surface Water Database for Louisiana – http://nwis.waterdata.usgs.gov/la/nwis/uv?site_no=295501090190400. Nutrient data obtained from the USGS gaging station was used to calculate monthly loads of nitrogen (nitrite + nitrate) and phosphorus (total phosphorus) based on average daily flow rates through the Davis Pond diversion and average monthly concentrations of nitrogen and phosphorus in the Mississippi River near St. Francisville, LA. Calculated loads through the Davis Pond Diversion from 2007 through May 2011 were based on Mississippi River concentrations derived from monthly loads. For the June, July, and August 2011 loads, average concentrations of nitrogen and phosphorus in the Mississippi River from the previous three years were used, since actual concentrations were not provided by USGS (i.e., the monthly nitrogen and phosphorus concentrations from June of 2007, 2008, and 2009 were averaged and multiplied by the flow to calculate the June 2010 loads).

2.10.2 Watershed Flow Mapping

Modeled flow diagrams from the National Hydrology Database (NHD) were used to illustrate the flow patterns from the Davis Pond Diversion Channel into Lake Cataouatche and JELA The NHD is a fundamental flow network consisting predominantly of stream/river and artificial path vector features. NHD flow diagrams represent the spatial geometry of the area by carrying the watershed attributes, modeling the water flow, and containing the linear referencing measures for locating events within the network.

2.10.3 Statistical Assessments of Survey Data

Statistical comparisons were performed using SAS statistical software. All data were evaluated for normality using the UNIVARIATE Procedure. Based on the results of the analysis, all analytes were found to be of non-normal distribution (with the exception of percent nitrogen in sediments). Therefore, non-parametric methods including Spearman rank correlation, Wilcoxon ranked sum, paired Wilcoxon ranked sum, Mann-Whitney U-test, and Friedman analysis were employed to assess the data. For nitrogen in sediments, parametric analyses were employed as applicable.

Spearman rank correlation analysis was used to assess relationships between locations (i.e., latitude and longitude), water quality parameters, and SAV and FAV community measures within JELA. Relationships were determined to be significant at an alpha of 0.05. A paired Wilcoxon ranked sum analysis was conducted to compare results between Spring and Fall 2011 surveys for analytes where data were not collected during the Fall 2010 surveys. In the case of data collected across the three surveys, a Friedman analysis was conducted (similar to a repeated

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MC 252 Oil Spill – Jean Lafitte National Historic Park and Preserve Submerged Aquatic Vegetation NRDA Spring 2011 Draft Report February 2012 measures analysis of variance [ANOVA]) to assess differences among surveys. A paired Wilcoxon ranked sum analysis was employed to evaluate post-assessment comparisons of the Friedman results for significant findings. To accommodate the multiple comparison issue for the Friedman post- assessment comparisons, a Bonferroni adjustment was conducted to revise the alpha for post-assessment comparisons to 0.0167 (Zar, 1999). A two-way sample test for proportion at alpha = 0.05 was used to compare differences in the occurrences of SAV among surveys.

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3.0 RESULTS

Fall 2010 The Fall 2010 survey was performed over the course of five days from September 7 through 11, 2010 between the hours of 0830 and 1600. JELA stations were sampled on September 7 through 9 and September 11, 2010. Reference stations were sampled over a three-hour time period on September 10, 2010 between 1130 and 1410. Cloud cover ranged from mostly sunny to partially cloudy. Air temperatures ranged from 31.1oC to 34.4oC.

Spring 2011 The Spring 2011 survey was performed from May 16 through 21, 2011 between the hours of 0830 and 1805. JELA stations were sampled on May 16 through 20, 2011, and reference stations were sampled on May 21, 2011. Cloud cover ranged from 0% to 40% throughout the field survey and air temperatures ranged from 21.8oC to 28.6oC. Photographs of all stations surveyed, with the exception of Station 31, are provided in Appendix A. Station 31 was mistakenly not photographed.

Fall 2011 The Fall 2011 survey was performed from September 12 through 17, 2011 between the hours of 0805 and 1652. JELA stations were sampled on September 12 through 16, 2011, and reference stations were sampled on September 17, 2011. Cloud cover ranged from 0% to 40% throughout the field survey and air temperatures ranged from 22.2oC to 33.9oC. Photographs of all stations surveyed are provided in Appendix A.

3.1 Mississippi River Flow and Nutrient Loading through Davis Pond Diversion

In response to the MC 252 Oil Spill, freshwater flow was increased below the Davis Pond Diversion to help prevent oil from entering JELA from the first week of May through the first week of September 2010. Monthly flow of water through the Davis Pond Diversion from January 2007 through December 2011 is shown in Figure 3-1. Average monthly flow increased from just over 4 billion ft3 in the January-April 2010 period prior to the sustained opening of the diversion to over 17 billion ft3 during the May-August period before again declining to just over 5 billion ft3 in the September-December period (Figure 3-2). Additionally, the total flow from May to August 2010 (70.2 billion ft3) was approximately 19.6 billion ft3 higher than the same period in 2009 (5.06 billion ft3) and 53.6 billion ft3 higher than the same period in 2011 (17.6 billion ft3) (Figure 3-3).

Monthly loads of nitrogen (nitrite + nitrate) and phosphorus (total phosphorus) were calculated based on average daily flow rates through the Davis Pond diversion and average monthly concentrations of nitrogen and phosphorus in the Mississippi River near St. Francisville, Louisiana. The increased flow from May-August 2010 resulted in 1.9 times higher loads of nitrogen and 1.7 times higher loads of phosphorus into the JELA watershed than had occurred on average over the same months in 2007 to 2009 (Table 3-1, Figure 3-3). Additionally, total nitrogen and phosphorous loads from May-Aug 2010 were estimated to be over three times greater than those calculated for 2011.

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Table 3-1. Monthly Loads of Nitrogen (Nitrite + Nitrate) and Phosphorus (Total Phosphorus) entering JELA through the Davis Pond Diversion Monthly NO2 + NO3 Load Calculations (Metric Ton or 1000 Kg) 2007 2008 2009 Avg (07-09) 2010 2011 May 299 320 693 437 585 8.8 June 145 355 516 339 527 156* July 124 420 179 241 467 334* Aug 134 154 179 156 620 107* Monthly Total Phosphorus Load Calculations (Metric Ton or 1000 Kg) 2007 2008 2009 Avg (07-09) 2010 2011 May 43.1 39.6 87.8 57 72.6 1.2 June 23.2 48.1 71.2 48 66.4 20.7* July 33.2 69.8 27.0 43 68.4 51.9* Aug 35.5 37.2 36.0 36 112.9 22.5* *Load calculated from the average of Mississippi River nutrient concentrations during that month in previous years.

Modeled flow diagrams from the NHD illustrate that flow from the Davis Pond Diversion Channel enters Lake Cataouatche and the upper, central portion of JELA via a series of small canals that empty into Bayou Segnette (Figure 3-4). The majority of flow from the Davis Pond Diversion enters into a marshy area north of Lake Cataouatche before flowing into the lake itself, while a smaller portion of the overall flow enters an unnamed canal and travels east along the northern park boundary before eventually flowing into Bayou Segnette.

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25,000,000,000

20,000,000,000

15,000,000,000 Feet

10,000,000,000 Cubic

5,000,000,000

0 Jul Jul Jul Jul Jul Jan Jan Jan Jan Jan Jun Jun Jun Jun Jun Oct Oct Oct Oct Oct Apr Apr Apr Apr Apr Feb Sep Feb Sep Feb Sep Feb Sep Feb Sep Dec Dec Dec Dec Dec Aug Aug Aug Aug Aug Nov Nov Nov Nov Nov Mar Mar Mar Mar Mar May May May May May

2007 2008 2009 2010 2011

Figure 3-1. Monthly Mississippi River Flow through the Davis Pond Diversion from January 2007 to December 2011

20,000,000,000 20,000,000,000

18,000,000,000 18,000,000,000

16,000,000,000 16,000,000,000 Water Water

14,000,000,000 14,000,000,000 River River

12,000,000,000 12,000,000,000

10,000,000,000 10,000,000,000 Mississippi Mississippi 8,000,000,000 8,000,000,000 of

of

6,000,000,000 6,000,000,000 Feet Feet

4,000,000,000 4,000,000,000 Cubic Cubic 2,000,000,000 2,000,000,000

0 0 Jan‐Apr May‐ Aug Sep‐ Dec 2007‐2009 2010 2011

Figure 3-2. Average Monthly Mississippi River Flow through the Davis Pond Diversion Before (Jan- Figure 3-3. Mississippi River Flow into JELA through the Davis Pond Diversion Apr), During (May-Aug), and After (Sep-Dec) Sustained Opening of the Diversion in 2010 from May – August Periods of 2007-2009, 2010, and 2011

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Figure 3-4. National Hydrology Database Map of Water Flow from the Davis Pond Diversion into JELA

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3.2 Water and Sediment Nutrients

3.2.1 Water Nutrients

Concentrations of TN and TP did not differ significantly between JELA and reference stations for any survey period (Mann-Whitney U-tests, p > 0.142). There was a significant increase in TN concentrations among surveys within JELA, with average concentrations increasing from 0.99 mg/L in Fall 2010 to 2.98 mg/L in Fall 2011 (Friedman test, p = 0.0015). TP concentrations in JELA did not differ among survey periods, nor were there any significant differences in either TN or TP concentrations at reference stations among surveys (Figure 3-5 and Figure 3-6).

In Fall 2010 there were no spatial trends in water nutrient concentrations either in latitude or longitude within JELA. By Spring 2011, a gradient of increasing TN from the lakeshore to the interior canals of the Preserve, as evidenced by a significant correlation between TN and longitude (Spearman rank correlation, r = 0.810, p < 0.05). This trend of increasing TN moving eastward in JELA was again evident in Fall 2011 (Spearman rank correlation, r = 0.790, p < 0.05).

4.00

3.50

3.00

2.50 (mg/L)

Fall 2010 2.00 Spring 2011 Nitrogen

1.50 Fall 2011 Total 1.00

0.50

0.00 JELA Reference

Figure 3-5. Average Total Nitrogen Concentrations in JELA and Reference Station Water Samples

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0.45

0.40

0.35

0.30 (mg/L)

0.25 Fall 2010 0.20 Spring 2011 Phosphorus Fall 2011 0.15 Total 0.10

0.05

0.00 JELA Reference

Figure 3-6. Average Total Phosphorus Concentrations in JELA and Reference Station Water Samples

3.2.2 Sediment Nutrients

Sediment TN did not differ significantly between JELA and reference stations during any of the three surveys (Mann-Whitney U-tests, p > 0.272), nor were there any significant difference in TN among the Fall 2010, Spring 2011, and Fall 2011 surveys (Friedman test, p = 0.0976; Figure 3-7). Sediment TP concentrations were significantly higher in JELA than reference during the Fall 2010 and Spring 2011 surveys (Mann-Whitney U-test, p = 0.019 and 0.033, respectively). By Fall 2011, TP concentrations at reference stations increased to a similar percentage as those in JELA, resulting in a significant difference in TP concentrations among surveys at reference stations (Friedman test, p = 0.0498). TP at reference stations was significantly higher in Fall 2010 than in Fall 2011 (Wilcoxon pairwise test, p = 0.0156; Figure 3-8).

There were no latitudinal or longitudinal gradients in either sediment TN or TP within JELA during any of the three surveys.

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1.20

1.00

0.80 (%)

Fall 2010 0.60

Nitrogen Spring 2011

Fall 2011 Total 0.40

0.20

0.00 JELA Reference

Figure 3-7. Average Total Nitrogen Concentrations in JELA and Reference Station Sediment Samples

0.100

0.090

0.080

0.070 (%) 0.060 Fall 2010 0.050 Spring 2011 Phosphorus 0.040 Fall 2011

Total 0.030

0.020

0.010

0.000 JELA Reference

Figure 3-8. Average Phosphorus Concentrations in JELA and Reference Station Sediment Samples

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3.3 Water Quality

Station-specific water quality measurements for DO, pH, turbidity, salinity, conductivity, water depth, light irradiance, Secchi depth, and chlorophyll a at JELA and reference stations for the Spring 2011 and Fall 2011 surveys are provided in Appendix B, while those from the Fall 2010 survey are provided in the April 2011 draft report (Weston, 2011). Mean ( standard error) water quality measurements are presented in Figure 3-9 and Figure 3-10 for chlorophyll a.

All water quality variables measured across the three surveys differed significantly among surveys in JELA, as did all variables except turbidity in the reference area (Table 3-2). In comparing water quality parameters measured in JELA in Fall 2010 to the subsequent 2011 surveys, there was a trend of increasing salinities and conductance from Fall 2010 through Spring and Fall 2011. These measures were also higher in 2011 surveys at reference stations, although the increases from Fall 2010 were less pronounced. Other notable changes in water quality parameters in JELA included decreases in Secchi depths across all surveys, with turbidity being over twice as high in 2011 surveys than Fall 2010. DO levels were highest in the Spring 2011 survey for both JELA and reference stations, with the lowest DO levels being measured consistently below 5-microgram per liter (µg/L) threshold for adverse effects to biological resources during the Fall surveys at reference stations in particular.

Table 3-2. Statistical Comparisons of Water Quality Parameters among Fall 2010, Spring 2011, and Fall 2011 Surveys Friedman Test Significant Wilcoxon Pairwise Tests Parameter Site p-values (p < 0.0167) Conductance JELA <0.0001 Fall '10 < Spring '11 & Fall '11 Dissolved Oxygen JELA 0.0003 Fall '11 < Spring '11 Salinity JELA <0.0001 Fall '10 < Spring '11 & Fall '11 Secchi Disk Depth JELA <0.0001 Fall '10 > Spring '11 & Fall '11 Turbidity JELA 0.0011 Fall '10 < Spring '11 & Fall '11 Water Temperature JELA <0.0001 Fall '10 > Fall '11, Spring' 11 < Fall '10 & Fall '11 pH JELA <0.0001 Fall '10 > Fall '11, Spring' 11 > Fall '10 & Fall '11 Conductance Reference 0.0224 Dissolved Oxygen Reference 0.0224 Salinity Reference 0.0224 Secchi Disk Depth Reference 0.0156 Turbidity Reference 0.2466 Water Temperature Reference 0.015 pH Reference 0.0067

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35.00 9.00 8.00 30.00 C)

o 7.00 ( 25.00 6.00

20.00 5.00 units) JELA JELA 4.00 15.00 (pH Reference Reference Temper atur e

pH 3.00 10.00 2.00 Water 5.00 1.00

0.00 0.00 Fall 2010 Spring 2011 Fall 2011 Fall 2010 Spring 2011 Fall 2011

0.80 1.60

0.70 1.40

0.60 1.20

0.50 1.00 (mS/cm)

(ppt) 0.40 JELA 0.80 JELA Reference Reference 0.30 0.60 Salinity 0.20 0.40 Conductance 0.10 0.20

0.00 0.00 Fall 2010 Spring 2011 Fall 2011 Fall 2010 Spring 2011 Fall 2011

0.70 12.0

0.60 10.0

0.50

(mg/L) 8.0 (m)

0.40 JELA 6.0 JELA Depth

Oxygen 0.30 Reference Reference 4.0

Sechhi 0.20

Dissolved 2.0 0.10

0.00 0.0 Fall 2010 Spring 2011 Fall 2011 Fall 2010 Spring 2011 Fall 2011

35.0 450.0

400.0 30.0 ) 2 350.0 25.0 300.0

(NTU) 20.0

250.0 JELA JELA (mmol/s/m 200.0 15.0 Reference Reference 150.0

Turbidity 10.0 100.0 5.0 Irradiance 50.0

0.0 0.0 Fall 2010 Spring 2011 Fall 2011 Spring 2011 Fall 2011 Figure 3-9. Mean Water Quality Measurements in JELA and Reference Stations

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In comparing water quality values between JELA and the reference area, pH, DO, and turbidity tended to be higher in JELA across all surveys (Figure 3-9); however, differences were only significantly different for DO and turbidity in Spring 2011 (Table 3-3). While average salinity and conductance measurements in JELA were over twice those of the reference area in Spring 2011, the only significant difference between the locations occurred in the Fall 2010 survey when average salinity and conductivity values were higher in JELA than the reference area.

Table 3-3. Statistical Comparisons of Water Quality Parameters between JELA and Reference Stations during Fall 2010, Spring 2011, and Fall 2011 Surveys Mann-Whitney U-Test p-values Parameter Fall Fall 2010 Spring 2011 2011 Depth 0.811 0.129 0.566 Temperature 0.111 0.002* 0.028* Salinity 0.000* 0.266 0.243 Conductance 0.000* 0.144 0.202 Dissolved Oxygen 0.248 0.259 0.014* pH 0.182 0.183 0.057 Turbidity 0.158 0.139 0.021* Secchi Depth 0.841 0.051 0.072 *significant at p < 0.05

During the 2006-2007 Poirrier et al. study, salinity and Secchi depths were recorded at a number of stations (Poirrier et al., 2009). Salinities within JELA ranged from 0.2 to 1.3 ppt during the prior study, while in the Fall 2010 study, salinities ranged from 0.2 to 0.3 ppt. During the Spring 2011 and Fall 2011 surveys salinity ranged from 0.1 to 1.1 ppt, and from 0.2 to 2.9 ppt, respectively. Thus, salinity conditions in JELA during the prior study ranged from fresh (< 0.5 ppt) to brackish (> 0.5 ppt), while during the Fall 2010 survey salinity levels were solely fresh. Following the Fall 2010 survey, salinity levels returned to ranging from fresh to brackish. Secchi depths ranged from 0.4 to 1.2 m in the 2006-2007 study and from 0.25 to 1.1 m in the Fall 2010 survey. In the Spring 2011 and Fall 2011 surveys, secchi depths ranged from 0.10 to 1.0 m and from 0.08 to 0.60 m. Therefore, it appears that there has been a decrease in light transparencies at JELA stations, particularly during the most recent survey in Fall 2011.

Chlorophyll a concentrations in the water column were significantly lower in JELA than the reference area during the Spring 2011 survey (Kruskal-Wallis, p = 0.044). By the Fall 2011 survey, however, average chlorophyll a concentrations had more than doubled in JELA, while those in the reference area slightly decreased (Figure 3-10) and there was no longer a significant difference between JELA and reference stations during the Fall 2011 survey (Kruskal-Wallis, p = 0.753). Additionally, there were no significant changes in chlorophyll a concentrations at either JELA or reference stations among surveys (Wilcoxon paired rank sum, p > 0.394).

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60

50

40 (ug/L)

30 Spring 2011 Fall 2011 Chlorophyll

20 Total

10

0 JELA Reference

Figure 3-10. Total Chlorophyll Concentrations at JELA and Reference Stations during Spring 2011 and Fall 2011 Surveys

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3.4 Submerged Aquatic Vegetation

Over the three surveys conducted in 2010 and 2011, a total of ten SAV species were observed within JELA, and five SAV species were observed within the reference area (Table 3-4). A table detailing the occurrences of SAV at each station is also provided in Appendix C.

Table 3-4. SAV Species Percent Occurrence at JELA and Reference Stations Fall 2010 Spring 2011 Fall 2011 SAV Species JELA Reference JELA Reference JELA Reference Cerratophyllum demersum 97 80 72 60 90 80 Najas guadalupensis 75 60 64 20 54 100 Hydrilla verticillata* 72 33 31 80 Cabomba caroliniana 69 56 67 20 Myriophyllum spicatum* 28 49 20 31 20 Vallisneria americana 25 28 21 Heteranthera dubia 11 8 0 Potamogeton pusillus 6 31 3 Egeria densa 3 5 Elodea canadensis 8 3 *Exotic species

A comparison of the relative abundance of SAV species from the Poirrier et al. 2006-2007 JELA study to the Fall 2010, Spring 2011, and Fall 2011 surveys was performed to assess potential impacts of increased flows of Mississippi River freshwater on JELA SAV community structure. Since the 2006-2007 survey, C. caroliniana was the only species to experience a sustained significant increase in relative abundance through all three subsequent surveys (Figure 3-11). The relative abundance of H. dubia consistently and significantly declined since 2006-2007. Likewise, N. guadalupensis has also declined in relative abundance since the Fall 2010 survey, with the Fall 2011 relative abundance below 2006-2007. Most of the other SAV species reported in the 2006-2007 study have been encountered at relatively consistent levels (e.g., M. spicatum and E. densa), have briefly spiked in abundance during one survey before approaching 2006- 2007 abundances (e.g., H. verticillata in Fall 2010), or have fluctuated in abundance seasonally (e.g., C. demersum occurs at higher abundance in the fall and P. pusillus occurs at higher abundance in the spring). Zannichellia palustris was the only species that was not observed since the 2006-2007 survey. This is not surprising, since Z. palustris was observed at only one station in the 2006-2007 study. Since 2006-2007, there has been only one new SAV species observed in JELA, E. canadensis, which was first encountered in Spring 2011.

All six of the native SAV species encountered within JELA during the Fall 2010 surveys declined in occurrence at stations by the Fall 2011 survey (Figure 3-11). Declines in percent occurrence ranged from 2% for C. caroliniana to 21% for N. guadalupensis. Across all three surveys C. demersum was the most prevalent species, occurring at 97% of stations in Fall 2010 before experiencing a seasonal decline to 72% of stations in Spring 2011 followed by an increase to 90% in the Fall 2010 survey. N. guadalupensis was the second most prevalent species during

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the Fall 2010 survey, occurring at 75% of stations, although its occurrence declined to 54% by the Fall 2011, at which point it was the third most common species. The third most common native species C. caroliniana was most common at stations during the fall surveys, when it occurred at greater than 67%, although it experienced a seasonal decline in Spring 2011 to 56%. V. americana and P. pusillus occurred at the greatest percentages of stations in Spring 2011, while H. dubia was most prevalent in Fall 2010, occurring at 11% of stations before declining to approximately 2% by Fall 2011. Additionally, two native species, E. densa and E. canadensis, were first encountered in the Spring 2011 survey and persisted at less than 10% abundance through Fall 2011. The non-native species H. verticillata also declined in abundance by more than half, while the other non-native M. spicatum increased in abundance from 25% in Fall 2010 to 49% in Spring 2011 and 31% in Fall 2011.

The reference area had a far less diverse SAV community, particularly within Fall 2010 when only two species were encountered, C. demersum and N. guadalupensis (Figure 3-12). In contrast to JELA, the occurrence of these species either remained constant or increased from the Fall 2010 to Fall 2011 surveys, although both species experienced seasonal declines in the spring. In Spring 2011, M. spicatum was also encountered at 20% of reference stations, as were H. verticulata (20%) and C. caroliniana (80%) by Fall 2011.

SAV Occurrence at JELA Stations in 2006‐2007, 2010, and 2011 SAV Occurrence in 2006‐2007 (n= 111 Sites) SAV Occurrence in 2010 (n= 36 Sites) SAV Occurrence in Spring 2011 (n= 39 sites) SAV Occurrence in Fall 2011 (n=39 sites)

100 90 80 *& $ ^# 70 60 50 40 %^*

Occurrence(%) 30

20 ^

SAV 10 0

* significant difference between Spring 2011 and Fall 2010 ^ significant difference between Fall 2011 and 2006‐2007 # significant difference between Spring 2011 and 2006‐2007 & significant difference between Fall 2011 and Fall 2010 $ significant difference between Fall 2010 and 2006‐2007 % significant difference between Fall 2011 and Spring 2011 Figure 3-11. SAV Occurrence at JELA Stations during 2006-2007, 2010, and 2011 Surveys

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Fall 2010 Spring 2011 Fall 2011

100 90 80 70 60 50 Occurrence

40 30

Percent 20 10 0

Figure 3-12. SAV Occurrence at Reference Stations during 2010-2011 Surveys

3.4.1 Submerged Aquatic Vegetation Diversity

SAV diversity within JELA ranged from zero to seven species per station during the Fall 2010 and Spring 2011 surveys and from zero to eight species during the Fall 2011 survey ( Figure 3-13). In the Fall 2010 survey, four stations contained one or zero SAV species, while in the Spring 2011 and Fall 2011 surveys, 11 stations and eight stations, respectively contained one or zero SAV species. Additionally, average SAV species diversity in JELA in Fall 2010 was 3.83 ± 0.24 species (mean ± standard error), declining slightly to 3.54 ± 0.37 species in Spring 2011 and 2.95 ± 0.26 species in Fall 2011. This declining trend in SAV diversity in JELA resulted in a significant difference among surveys (Friedman test, p = 0.0021). While SAV species diversity in Fall 2010 was not significantly different from Spring 2011 (Wilcoxon test, p = 0.1363), it was significantly higher than species diversity in Fall 2011 (Wilcoxon test, p = 0.0001).

SAV diversity within the reference area ranged from zero to two species in Fall 2010, zero to three species in Spring 2011, and one to four species in Fall 2011 ( Figure 3-13). Accordingly, there was a trend of increasing species diversity in the reference area across surveys (Friedman Test, p = 0.0156; Figure 3-14). Reference area SAV diversity averaged 1.4 ± 0.4 species in Fall 2010, 1.0 ± 0.55 species in Spring 2011, and 3.0 ± 0.55 species in Fall 2011.

SAV diversity within the reference area was significantly lower than JELA during Fall 2010 (Wilcoxon test, p = 0.003) and Spring 2011 (Wilcoxon test, p = 0.023), while in Fall 2011, it was nearly identical to JELA (Wilcoxon test, p = 0.880).

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7 V. americana 6 P. pusillus 5 species

N. guadalupensis

SAV 4

M. spicatum of

3 H. verticillata

2 H. dubia Number E. canadensis 1 E. densa 0 C. demersum 1a2345678910111213141516171819202122232425262728a29a30313233343536R1R2R3R4R5 C. caroliniana JELA Stations Reference Stations

8 7 V. americana 6 P. pusillus species

5 N. guadalupensis SAV 4 M. spicatum of 3 H. verticillata 2 H. dubia Number 1 E. canadensis 0 1b2345678910111213141516171819202122232425262728b29b30313233343536373839R1R2R3R4R5 E. densa C. demersum JELA Stations Reference Stations C. caroliniana Indicates station was not sampled in 2010 9 V. americana 8 7 N. guadalupensis 6 M. spicatum species

5 H. verticillata SAV

of 4

H. dubia 3 E. canadensis

Number 2

1 E. densa 0 C. demersum 1b2345678910111213141516171819202122232425262728b29b30313233343536373839R1R2R3R4R5 C. caroliniana JELA Stations Reference Stations

Indicates station was not sampled in 2010 Figure 3-13. SAV Diversity at JELA and Reference Stations during Fall 2010 (A), Spring 2011 (B), and Fall 2011 (C)

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4.50 4.00 3.50 3.00 2.50 Richness

2.00 1.50 Species 1.00 0.50 0.00 Fall 2010 Spring 2011 Fall 2011 Fall 2010 Spring 2011 Fall 2011

JELA Reference

Figure 3-14. SAV Species Richness at JELA and Reference Stations

3.4.2 Submerged Aquatic Vegetation Distribution

In Fall 2010, SAV species richness generally was greatest along the western portion of JELA and decreased moving east into the canals. The majority of stations located along the shorelines of Lake Cataouatche and the upper portion of Lake Salvador had four or more SAV species. The most prevalent species, C. demersum, N. guadalupensis, C. carloniana, and H. verticulata, occurred throughout all areas of JELA (Figure 3-15). H. dubia occurred in the northern portion of JELA along the shoreline of Lake Catauoatche and within the inland channels. M. spicatum occurred along the shorelines of Lakes Cataouatche and Salvador, as well as one station at the northern portion of Bayou Segnette. V. americana occurred in the western portion of JELA at three stations along Bayou Segnette, five stations on the northern shoreline of Lake Salvador, and one station (Station 4) on Pipeline Canal. P. pusillus was only observed at two stations located along the shoreline of Lake Salvador.

During the Spring 2011 survey, SAV species richness was greatest in the north central and southeastern portions of JELA. Most notably, species richness along the lakeshore stations declined from an average of 4.42 SAV species per station in Fall 2010 to 2.58 species in Spring 2011. Four stations in the Spring 2011 survey had no SAV; two interior stations (Stations 3 and 5) had no SAV and were completely covered by FAV, while at the two other stations (Stations 35 and 38) open water existed and there was little to no FAV cover. Four of the most prevalent SAV species, C. demersum, N. guadalupensis, C. caroliniana, and H. verticulata, occurred throughout all areas of JELA while M. spicatum occurred almost exclusively along the shorelines of Lakes Cataouatche and Salvador and the northern portion of Bayou Segnette (Figure 3-16). The small pondweed, P. pusillus, increased in occurrence from 6% of stations during the Fall 2010 survey to 31% of stations during the Spring 2011 survey along interior canals. Two SAV species that were not observed during the Fall 2010 survey, E. canadensis and E. densa, were located along the northern portion of Bayou Segnette.

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During the Fall 2011 survey, SAV species richness was greatest in the north central and southeastern portions of JELA and remained lowest along the lakeshores, with an average of 2.67 species per station. SAV was not detected at Stations 3 and 12, which were located within the interior of the Preserve and were completely covered on the surface by a thick mat of FAV. The most prevalent SAV species, C. demersum, occurred throughout all areas of JELA (Figure 3-17) while C. caroliniana and N. guadalupensis occurred primarily along the interior canals. M. spicatum occurred almost exclusively along the shorelines of Lake Salvador, and Bayou Segnette. P. pusillus, which occurred at 31% of stations during the Spring 2011 survey, was not observed at any stations in Fall 2011. E. canadensis and H. dubia were observed along the northern portion of Bayou Segnette, while E. densa was found on Bayou Segnette and Bayou Aux Carpes in the southeastern portion of JELA.

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Figure 3-15. Distribution of SAV Species at JELA and Reference Stations during the Fall 2010 Survey

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Figure 3-16. Distribution of SAV Species at JELA and Reference Stations during the Spring 2011 Survey

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Figure 3-17. Distribution of SAV Species at JELA and Reference Stations during the Fall 2011 Survey

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3.4.3 Change in SAV Diversity

Following the Fall 2010 survey, SAV species richness declined significantly among the stations located along the lake shorelines and in the upper portion of JELA. Reductions in species diversity were correlated with proximity to the lakeshores where Davis Pond Diversion flows were predicted to occur most strongly based on watershed contours (Pearson Correlation r = 0.349, p = 0.018).

Reductions in species richness were also more pronounced at stations located in northerly portions of the park closer to the Davis Pond Diversion, which is evidenced by a significant negative correlation between latitude and species loss (Pearson correlation r = -0.346, p = 0.039). Of the 14 stations located north of Couba Island that were sampled in Fall 2010 and Fall 2011, (both along the lakeshore and in the interior canals), 78% decreased by one or more species of SAV; and 71% decreased by two or more species of SAV since Fall 2010. Overall, between the Fall 2010 survey and the Fall 2011 survey, 20 stations within JELA declined by one or more species of SAV, while four stations increased by one or more species of SAV, and nine stations retained the same number of SAV species (Figure 3-18).

In contrast to the decline in SAV species diversity observed at most JELA stations between Fall 2010 and Fall 2011, each of the five reference area stations during this time period experienced an increase in SAV species diversity (Figure 3-18). Two of the reference stations increased by one SAV species while three of the reference stations increased by two SAV species.

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Figure 3-18. Changes in SAV Species Diversity between Fall 2010 and Fall 2011

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3.5 Floating Aquatic Vegetation

The diversity and percent cover of FAV is reported for each station surveyed in Spring and Fall 2011 in Appendix C.

3.5.1 Floating Aquatic Vegetation Percent Cover

Average FAV cover in JELA was consistently lower than in the reference area across all surveys (Figure 3-19); however, differences were at most marginally significant (Mann-Whitney U-tests, p-values > 0.054). FAV cover within JELA was greatest during the Fall 2010 survey, with significantly lower cover observed at stations during Spring 2011 (Wilcoxon test, p = 0.0011) and then Fall 2011 surveys (Wilcoxon test, p-value = 0.0033). FAV cover at reference stations remained largely consistent throughout the three surveys, with no significant differences among surveys (Wilcoxon test, p = 0.449).

During each of the surveys, FAV cover in JELA was lowest along the lakeshores (Figure 3-20, Figure 3-21, and Figure 3-22). Stations with the highest FAV cover (i.e., > 75%) were located in protected canals in the interior of JELA. Accordingly, FAV cover was positively correlated with longitude in Fall 2010 (Spearman rank correlation, r = 0.523), Spring 2011 (r = 0.721), and Fall 2011 (r = 0.624).

70

60

50

40 Cover

30 Percent 20

10

0 JELA Reference JELA Reference JELA Reference Fall 2010 Spring 2011 Fall 2011

Figure 3-19. Floating Aquatic Vegetation Cover Observed in JELA and Reference Area Stations

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Figure 3-20. Percent Cover of Floating Aquatic Vegetation within JELA and the Reference Area during the Fall 2010 Survey

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Figure 3-21. Percent Cover of Floating Aquatic Vegetation within JELA and the Reference Area during the Spring 2011 Survey

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Figure 3-22. Percent Cover of Floating Aquatic Vegetation within JELA and the Reference Area during the Fall 2011 Survey

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3.5.2 Floating Aquatic Vegetation Species Richness

FAV species richness was, on average,e over two times greater at reference stations than at JELA stations (Figure 3-23), resulting in a significant difference between locations during both Spring and Fall 2011 surveys (Mann-Whitney U-tests, p = 0.003). FAV richness did not change substantially between Spring and Fall 2011 surveys at either JELA or reference stations (Wilcoxon tests, p = 0.842 and 0.317, respectively).

FAV Species Richness

Spring 2011 Fall 2011

12.0

10.0

8.0 Species

of 6.0

4.0 Number

2.0

0.0 JELA Reference

Figure 3-23. Average FAV Species Richness at JELA and Reference Stations

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3.5.3 Salvinia molesta and Oxycaryum cubense

During the 2006-2007 survey, Poirrier et al. identified 17 FAV species comprised of plants and algae (2009). Relative abundance data from stations was not reported for most FAV species during the 2006-2007 survey, with the exception of S. molesta (giant salvinia). S. molesta is a rapidly growing invasive FAV species that is federally listed as a noxious weed. During the 2006-2007 survey, S. molesta was observed at ten stations (7% of stations) within the southern portion of JELA exclusively along the Bayou Segnette Waterway and lower Pipeline Canal. By the Fall 2010 survey, S. molesta was encountered at 26 stations (72%), with a range that extended nearly the entire north-south length of JELA throughout Bayou Segnette Waterway and Pipeline Canal, as well as along the shorelines of both Lakes Salvador and Cataouatche (Figure 3-24). In Spring 2011, S. molesta was observed at 20 stations in JELA (51%) (Figure 3-25), but at only one site along the lakeshore. In Fall 2011, S. molesta was observed at 82% of stations in JELA. Thus, there has been a significant increase in SAV relative abundance in JELA, most notably within the interior canals, but also along the lake shorelines (Friedman test, p = 0.025).

Within the reference area, S. molesta was found at all stations during Fall 2010 and Spring and Fall 2011 surveys (Figure 3-25), with percent cover ranging from 17 to 38% in Spring 2011 and 12 to 39.5% in Fall 2011. Occurrence of S. molesta in the reference area tended to be higher than JELA, and was significantly higher in Spring 2011 (Mann-Whitney U-test, p = 0.041). Percent cover was only significantly greater at reference stations than JELA in Spring 2011 (Mann-Whitney U-test, p = 0.012), while percent cover at both JELA and reference stations averaged 21% in Fall 2011.

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Figure 3-24. Comparison of Salvinia molesta Occurrence between Fall 2007 and 2010 Surveys

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Jela Reference 100 90 80 70 (%) 60 50 40

Occurrence 30 20 10 0 Fall 2010 Spring 2011 Fall 2011

Figure 3-25. Salvinia molesta Occurrence Across JELA and Reference Stations

Percent cover of S. molesta was greatest along the interior portions of JELA and was lowest along the lakeshores, as indicated by a positive correlation with longitude in both Spring 2011 and Fall 2011 (Figure 3-26; Spearman rank correlation, r = 0.492 and 0.695, respectively). S. molesta and O. cubense coverage at Station 2 during Stations 1b, 2, 3, and 12 all averaged greater than Fall 2011 survey 50% S. molesta cover. With the exception of Station 21 and Station 9, all of the lakeshore stations averaged less than 5% cover. At stations with close to 100% FAV coverage, S. molesta coverage may have been slightly underestimated due an overstory of other floating aquatic species

such as Oxycaryum cubense.

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Figure 3-26. Percent Cover of Salvinia molesta during the Fall 2011 Survey

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Oxycaryum cubense (Cuban bulrush) occurrence was recorded during the Fall 2011 survey. O. cubense is a perennial, rhizomatous, emergent sedge that forms large monotypic floating mats on the surface of standing water. Within JELA it co-occurs with S. molesta and appears to thrive in interior canal areas that are already covered by mats of S. molesta. The roots of O. cubense act to thatch together mats of S. molesta in such a way that the mat becomes similar to a heavy carpet that allows little to no light to penetrate beneath it and is not susceptible to being broken up by strong winds.

O. cubense occurred at 67% of JELA stations and at 80% of reference stations during the Fall 2011 survey (Figure 3-27). O. cubense was also likely present at many of these stations during the Spring 2011 survey as well, but could not easily be identified in the field due to the absence of floating structures at that time. There was no significant difference in O. cubense occurrence between JELA and reference stations (Mann- Whitney U-test, p = 0.55).

100 90 80 70 60 50 Occurrence

40 30 Percent 20 10 0 JELA Ref

Figure 3-27. Occurrence of Oxycaryum cubense during Fall 2011

3.5.3.1 Change in appearance of Stations among Survyes Several stations were observed to have changed dramatically in appearance from Fall 2010 to Fall 2011. In almost all cases, this was due to the encroachment of S. molesta and other FAV such as O. cubense and the water hyacinth Eichornia crassipe. The following series of photos were taken at Stations 2, 12, and 25 from nearly the same position during the Fall 2010, Spring 2011, and Fall 2011 surveys (Figure 3-28). At these sites, water that had light to moderate FAV cover in Fall 2010 had become, or was in the process of becoming, a heavy mat of FAV that likely blocked nearly all available light from penetrating to support SAV growth.

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Site 2: Fall 2010 Site 2: Spring 2011 Site 2: Fall 2011

Site 12 Fall 2010 Site 12 Spring 2011 Site 12 Fall 2011

Site 25 Fall 2010 Site 25 Spring 2011 Site 25 Fall 2011 Figure 3-28. Photographic Documentation of Surface Vegetation Changes at Three JELA Stations over Time

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3.5.4 Herbicide Usage

Herbicide has been applied regularly in recent years both within JELA and within the reference area to control the spread of FAV. Table 3-5 provides a list of the areas that have been treated with the herbicide 2,4-D from October 2009 to May 2011.

Area in JELA recently sprayed with 2,4-D herbicide

Table 3-5. Recent Reported Herbicide Application in the Vicinity of JELA

Date Waterways Treated Herbicide Acreage Treated Bayou Segnette, Tarpaper Canal, Lower Kenta Canal, 10-16-09 2,4-D 250 Bayou Bardeaux, Bayou Boeuf, Couba Island Bayou Segnette, Kenta 8-10-10 2,4-D 150 Canal All of JELA with exception of 11-6-10 2,4-D 375 Lake Cataouatche shoreline 4-20-11 Bayou des Familles 2,4-D 30 Tarpaper Canal, Lower Kenta 5-14-11 Canal, Bayou Bardeaux, 2,4-D 175 Bayou Boeuf, 5-15-11 Area near Bayou Aux Carpes 2,4-D 30

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4.0 DISCUSSION

In response to the MC 252 Oil Spill, more than 70 billion ft3 of Mississippi River freshwater was released from the Davis Pond Diversion to Lake Cataouatche and JELA from May to August 2010, which was an increase of nearly 20 billion ft3 over the same period in 2009 and over 50 billion ft3 in 2011. Sustained increases in flow resulted in reduced salinities in JELA as well as increased loads of nitrogen by 879 metric tons and phosphorus by nearly 200 metric tons into the downstream system leading to JELA throughout the summer and into the fall of 2010. These changes in physical habitat conditions have coincided with changes in SAV community structure, including reductions in SAV diversity in JELA, while simultaneously SAV diversity at reference stations has increased. Additionally, there have been notable increases in abundance of non-native SAV and FAV species, including highly invasive species such as S. molesta and O. cubense. All of these factors provide evidence for response injuries, as discussed further below.

4.1 Water Quality

Evidence for response-driven reductions in salinity levels and other water quality parameters was evident in JELA. These changes have important ramifications for SAV as well as the biota that inhabit the Preserve. Freshwater conditions (i.e., salinities < 0.5 ppt) extended throughout all areas of JELA during the Fall 2010 survey. Typically in the fall, salinity levels have ranged from fresh in the northern portion of the Preserve to brackish in the southern portion (Swarzenski, 2004; Poirrier et al., 2009). During the 2006-2007 Poirrier et al. survey (2009), salinities ranged from 0.2 to 1.3 ppt as compared to 0.22 to 0.32 ppt in Fall 2010. In Spring 2011 and Fall 2011, salinities ranged from 0.13 to 1.11 ppt, and from 0.19 to 2.86 ppt, respectively. The loss of brackish conditions within JELA in the summer of 2010 equates to a reduction in habitat heterogeneity, which may have favored freshwater SAV species over brackish species. Additionally, the increase in freshwater conditions may have facilitated the development of dense mats of surface vegetation comprised of FAV (predominantly S. molesta, E. crassipes, and O. cubense) that reduced light transmissivity and DO levels. These changes have the potential to further undermine habitat quality for not only SAV, but also other biota. Reduced light transmissivity reduces colonization depth of SAV (Dennison, 1987; Duarte, 1991) and favors the persistence of perennial plants with surface and near-surface growth, while undermining the recruitment and growth potential of annual SAV species (Poirrier et al., 2010). This can result in reduced diversity of the native SAV community. Additionally, the formation of dense surface mats of FAV can lead to reduced oxygen levels, often to concentrations (i.e., < 0.5 mg/L) that limit benthic and demersal fish and invertebrate communities (Schultz, 2006).

The sustained flows of Mississippi River freshwater from the Davis Pond Diversion substantially increased nutrient loads to the watershed that drains to JELA. From May to Aug 2010, calculated nitrogen and phosphorus loads increased by nearly 900 metric tons and 200 metric tons, respectively, over the same period in 2009. Although Fall 2010 and Spring 2011 sediment phosphorus concentrations were significantly higher in JELA than in the reference area, nitrogen sediment levels and nitrogen and phosphorus levels in the waters of JELA were not significantly different than those of the reference area. Additionally, in comparing average TN concentrations (i.e., nitrite + nitrate + ammonia + organic nitrogen) in the water column between a prior USGS study conducted in 1999 and 2000 (Swarzenski, 2004) and the 2010 JELA survey, average concentrations were not substantially different. The average TN concentration in 1999-2000

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study was 0.84 mg/L as compared to 0.99 mg/L in 2010. Therefore, the increased freshwater flows from the Davis Pond Diversion did not appear to substantially elevate nutrient levels within the waters of JELA. This may have been due to the ability of the wetland system to rapidly assimilate nutrients into new vegetative growth.

Light availability (as measured by secchi depths and turbidity) decreased in JELA following the Fall 2010 survey. While secchi depths were not immediately reduced by increased freshwater flows into JELA during the Fall 2010 survey relative to the 2006-2007 Poirrier et al. survey, secchi depths measured in Fall 2011 were often below the range of depths measured in the 2006- 2007 study. While JELA secchi depths measured in Fall 2010 survey were equivalent to those of the reference area, 2011 JELA secchi depths decreased relative to the reference area, as evidenced by marginal significant differences. Light availability is an important factor that limits the depths at which SAV can survive (Cho and Poirrier, 2005), and this reduction in light availability, in conjunction with changes in salinity, may undermine the habitat quality for SAV.

4.2 Submerged Aquatic Vegetation

SAV community structure is known to be largely determined by physical habitat conditions, in particular salinity (Poirrier and Cho, 2005). Associated with the changes in water quality measures, there were several notable changes in SAV community structure following the 2006- 2007 survey. Several native and non-native SAV species that favor freshwater conditions initially increased in abundance. These species included the natives C. demersum, C. caroliniana, and N. guadalupensis, as well as the non-native H. verticillata, which showed the most substantial increase in relative abundance within JELA, increasing by nearly threefold. However, following the Fall 2010 survey, the relative abundance of all six native SAV species, as well as that of the non-native H. verticillata decreased. C. demersum, N. guadalupensis, and H. verticillata returned to approximate pre-impact levels, while C. caroliniana was the only SAV species that increased substantially in relative abundance following the sustained opening of the Davis Pond Diversion and maintained the increased abundance in subsequent surveys relative to 2006-2007. The decline in relative abundance of P. pusillus during fall surveys and increase during spring surveys is typical for P. pusillus, since it is generally more abundant in late winter and early spring and decreases in the summer and fall (Poirrier et. al., 2009). Both E. densa and Z. palustrius occurred at less than 5% of stations in the 2006-2007 study. E densa was not found at any stations in Fall 2010 but did occur at approximately 5% of stations in subsequent surveys, while Z. palustrius has not been observed at any stations since the 2006-2007 study. Lastly, there has been an introduction of a new species to JELA, E. canadensis, which previously had a distribution that was north of the Preserve.

The most notable change in SAV community structure has been an overall reduction in SAV diversity at JELA stations from the Fall 2010 to Fall 2011 survey, while the SAV diversity has significantly increased in the reference area over the same period. SAV diversity decreased on average by nearly one species per station in JELA, while diversity increased by over 1.5 species on average at reference stations. The decline in community diversity following exposure to increased freshwater flows from the sustained opening of the Davis Pond Diversion coupled with an increase in diversity at the reference area provides the strongest evidence of a potential impact under traditional assessments of impacts, which use a variety of before after control impact

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(BACI) studies. The current study uses a modified version of this model since baseline data was available for the impacted site but not the reference site.

Information on the SAV species observed in JELA during the Fall 2010, Spring 2011, and Fall 2011 surveys compiled from Poirrier et al. (2009; 2010) is provided as follows.

Ceratophyllum demersum (coontail) was the most prevalent SAV species in every survey, occurring at over 70% of stations in 2006-2007 and Spring 2011, and at over 90% of stations in Fall 2010 and Fall 2011. Abundance of C. demersum in Fall 2010 was significantly higher than in 2006-2007 and Spring 2011. This native plant is an important habitat-forming freshwater species that attaches to the bottom with rhizoids. Lacking true roots, plants are easily dislodged by wave action and currents. The overall increase in abundance of this species since 2006-2007 may be partially explained by increases in freshwater flows that have the potential to facilitate vegetative reproduction and transport of this plant.

Najas guadalupensis (common water nymph) is a native species that occurs in both freshwater and brackish waters of JELA (< 3.5 ppt). This was the second most abundant species during three of the four surveys, occurring at over 50% of stations. Although no statistical differences were found among surveys, a declining trend in abundance of N. guadalupensis has occurred since the Fall 2010 survey. Given this plant’s tolerance for a wider range of salinities, it is likely that it will remain abundant throughout the Preserve provided increased FAV cover does not prevent light from reaching it.

Hydrilla verticillata (water thyme) is a non-native, highly invasive species that reproduces by fragmentation, seeds, turions, and tubors. It was previously found in the northwestern portion of JELA at stations with salinities ranging from 0.2 to 0.6 ppt. Reductions in salinity coupled with increased flows throughout JELA may have facilitated the southern and eastern expansion of this species throughout JELA in Fall 2010. However, a significant decline in the relative abundance of H. verticillata occurred between Fall 2010 and both Spring 2011 and Fall 2011. This species of SAV may have been unable to tolerate the return of higher salinities measured across JELA following the reduction of the freshwater flow through the Davis Pond Diversion. The relative abundance of H. verticillata in Spring 2011 and Fall 2011 was similar to its relative abundance in 2006-2007.

Cabomba caroliniana (fanwort) is a native freshwater-limited species (< 0.5 ppt) that was previously found at 13 interior stations east of Bayou Segnette. Reductions in salinity during the summer of 2010 may have allowed this species to establish new footholds throughout most of JELA. From 2006-2007 to Fall 2010, occurrence of C. caroliniana increased approximately five fold, and has remained relatively consistent levels since Fall 2010 (occurring at 56% to 69% of stations from Fall 2010 through Fall 2011).

Myriophylllum spicatum (Eurasion watermilfoil) is a non-native nuisance SAV species that has the potential to displace native species. This species has a wide salinity tolerance, as it is reported to survive in waters with salinities up to 20 ppt. With the exception of the Spring 2011 survey, the overall distribution and abundance of M. spicatum has remained relatively constant since 2006-2007 (occurring at 28 to 31% of stations and occurring almost exclusively at

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MC 252 Oil Spill – Jean Lafitte National Historic Park and Preserve Submerged Aquatic Vegetation NRDA Spring 2011 Draft Report February 2012 lakeshore stations). In Spring 2011, M. spicatum occurred at 49% of stations and expanded its range into Bayou Segnette and several other interior canal stations.

Vallisneria americana (water celery) is a native species that occurs in both fresh and brackish waters and does not form surface mats. Its relative abundance slightly increased from 2006-2007 to Spring 2011 before declining slightly in Fall 2011. There is concern that this species could be subject to competitive exclusion by mat-forming SAV and FAV following the winter dieback. Additional spring surveys will help to better assess this contention.

Heteranthera dubia (water star-grass) is a native species that decreased in abundance every year since the 2006-2007 survey. H. dubia originally occurred at 17% of stations in the 2006- 2007 survey, but it was absent from all 39 stations within JELA in Fall 2011. The potential loss of this species may have important ramification to overall JELA habitat quality since it can form large beds that provide habitat for invertebrates, fish, and waterfowl.

Potamogeton pusillus (baby pondweed) is tolerant of higher salinities (up to 3.5 ppt), and generally is more prevalent in the late winter and early spring before decreasing in abundance during the summer and fall (Poirrier et al., 2010). Thus, the observed decline of P. pusillus during the Fall 2010 and Fall 2011 surveys, and rise during the Spring 2011 survey, is more likely a seasonal shift than a response to increases in flows of Mississippi River to JELA. Follow-on studies performed in the spring will be useful in testing this assertion.

Egeria densa (Brazilian waterweed) is a non-native species that is similar in appearance to Hydrilla verticillata. E. densa occurred at 5% or less of the JELA stations in each of the surveys since 2006-2007, and has not been observed at any reference stations. Because it does not occur at salinities greater than 0.5 ppt, salinity tolerance appears to restrict its distribution within JELA.

Elodea canadensis (common waterweed) is a native species to North America that is typically found in more northern areas of the U.S. It likely arrived in JELA recently, since there was no known record of its existence in JELA prior to its discovery in Spring 2011. Fragments of E. canadensis may have floated down the Mississippi River and entered the park via the Davis Pond Diversion Channel or may have become attached to the hull or motor of a vessel that entered the park after coming into contact with it in another body of water. E canadensis occurred at three stations in Spring 2011 and at one station in Fall 2011. Future studies can determine if E canadensis is broadening its range throughout JELA.

4.3 Floating Aquatic Vegetation

One of the most pronounced changes in JELA since the 2006-2007 surveys has been the substantial increase and proliferation of the federally-listed noxious weed, S. molesta. This non- native and invasive species was originally observed at only ten stations located within the southern portion of JELA in September 2007. Since that time it has spread throughout JELA, and now occurs along the entire length of the Bayou Segnette Waterway and Pipeline Canal, as well as along the lake shorelines. Additionally, S. molesta was found at all stations within the reference area. This species has the capacity to dominate areas with slow-moving water, forming dense mats that overgrow and shade native species (Poirrier et al., 2009). Additionally, it is of

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particular concern because it does not appear to be salinity limited within JELA, as it can survive in salinities up to 7 ppt (Poirrier et al., 2009), and is somewhat resistant to herbicide applications. Correlations with water quality parameters indicate that the presence of S. molesta may, through shading and organic decomposition of its leaves, affect water quality. In Spring 2011 and Fall 2011, occurrence of S. molesta was negatively correlated with pH, and was positively correlated with salinity and conductivity in Spring 2011, and in Fall 2011, S. molesta occurrence was negatively correlated with DO. S. molesta may also help to facilitate the spread of the invasive species O. cubense, which was found to occur at 67% of JELA stations and 80% of reference stations in Fall 2011.

The increase in the abundance and cover of invasive species, such as S. molesta, O. cubense, and E. crassipes, has altered the surface water landscape and limited light penetration at some stations located in the interior canals of JELA. Although herbicide sprays have been used throughout JELA and the reference area, they appear to be only minimally effective in controlling the spread of S. molesta. SAV appears to survive under FAV coverage as high as 75%; however, as FAV approaches 100% coverage of a station, SAV diversity is reduced, as evidenced by the low SAV diversity at stations with greater than 90% FAV cover. Three of the four stations with 90% or greater FAV cover in Fall 2011 contained one or fewer SAV species. These three stations were covered by a thick blanket of S. molesta and O. cubense that greatly reduced sub-surface light levels. The fourth station was covered by E. crassipes and Lemma sp. (duckweed), which, unlike S. molesta, does allow light to penetrate its canopy and may be more susceptible to movement of the mat as a result of wind.

4.4 Reference Area Assessment

The Bayou des Allemands and Humble Canal reference area was selected because it was located in close proximity to JELA and was not exposed to flows from the Davis Pond Diversion. Additionally, both JELA and the reference area contained shallow channels of similar depth, and the reference area was located at a latitude that was consistent with the northern portion of JELA. However, the reference area had known preexisting limitations, including its proximity to agricultural areas that may provide sustained nutrients to the channels and, more importantly, its lack of existing data on water quality conditions and the SAV community.

In general, the reference area was found to contain a low-diversity SAV community comprised primarily of the species C. demersum, N. guadalupensis, and H. verticiallata. A total of five species occurred in the reference area in Fall 2011, while only two and three species, respectively, occurred in Fall 2010 and Spring 2011. Across all surveys, reference stations had a higher percentage of FAV cover and diversity than JELA, and had a higher occurrence of S. molesta.

Water quality conditions also differed, as there were lower pH, turbitity, and DO levels across all surveys in the reference area compared to JELA. Statistically significant differences occurred for salinity in Fall 2010 (higher in JELA than in the reference area), DO (lower in reference area than in JELA), and turbidity (lower in reference area than in JELA) in Fall 2011. The strong relationship of lower DO levels in areas with higher FAV cover is predictable since higher density mats are unable to photosynthesize and produce oxygen at sufficient levels to counterbalance higher respiration rates. The substantial differences in SAV community structure

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between the reference area and JELA paired with differences in water quality may be informative for predicting future potential habitat quality changes at JELA. A continued increase in the spatial distribution of S. molesta within JELA may lead to reduced SAV diversity, as SAV growth can be limited by light availability, which is often limited by this surface-mat-forming species. In this scenario, the SAV community in JELA would converge toward the relatively low-diversity assemblage of the reference area, similar to the trend in diversity that has been observed.

While differences between the reference area and JELA can be informative, care must be taken in inferring either the presence or absence of Davis Pond Diversion impacts from differences between JELA and the reference area since there were preexisting differences between these areas prior to the increased flow event. The lack of pre-impact data for the reference area makes it difficult to assess differences in the trends or trajectories of community structure or water quality between the two areas. This limitation, however, is reduced through repeated studies within both JELA and the reference area to determine whether community conditions are converging, diverging, or remaining relatively constant.

4.5 Future Studies

Two follow-up field surveys are proposed in the spring and fall of 2012 to more fully determine if the loss of SAV diversity and increase in S. molesta and O. cubense abundance within JELA will persist, providing further data required to assess the magnitude and duration of potential damages. Further studies are needed to determine the trajectory of recovery of the SAV community following the May-August 2010 period of increased flow of Mississippi River freshwater to JELA from the Davis Pond Diversion. By performing studies in the spring and fall, SAV community seasonal dynamics that are important to recovery, such as recruitment and re-growth, may be further assessed. Spring and fall 2012 surveys are proposed to quantify physical and chemical water quality parameters, sediment and water nutrient levels, and potential shifts in SAV community structure and/or FAV species abundance as compared to the reference area and prior surveys.

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5.0 REFERENCES

Aspila, K.I., H. Agemian, and A.S.Y. Chau. 1976. Semi-automated method for the determination of inorganic, organic and total phosphate in sediments. Analyst 101:187-197.

Cho, H.J. and M.A. Poirrier. 2005. A model to estimate potential SAV (submersed aquatic vegetation) habitat based on studies in Lake Pontchartrain. Restoration Ecology 13:623–629.

Davis, G.J. and M.M. Brinson. 1980. Responses of submersed vascular plant communities to environmental change. US Fish and Wildlife Service, Kearneysville, WV. FWS/OBS-79/33. 70 pp.

Day, J. W., Jr., C. A. S. Hall, W. M. Kemp, and A. Yanez-Arancibia. 1989. Estuarine Ecology. John Wiley and Sons, New York.

Dennison, W.C. 1987. Effects of light on seagrass photosynthesis, growth, and depth distribution. Aquatic Botany 27:15-26.

Dennison, W.C., R.J. Orth, K.A. Moore, J.C. Stevenson, V. Carter, S. Kollar, P.W. Bergstrom, and R. Batiuk. 1993. Assessing water quality with submersed aquatic vegetation. Bioscience 43:86–91.

Dodson S.I., R.A. Lillie, and S.Will-Wolf 2005. Land use, water chemistry, aquatic vegetation, and zooplankton community structure of shallow lakes. Ecological Applications 15:1191- 1198.

Duarte, C.M. 1991. Seagrass depth limits. Aquatic Botany 40:363-377.

Harlin, M.M. 1995. Changes in major plant groups following nutrient enrichment. Pp. 173–188, In A.J. McComb (Ed.). Eutrophic Shallow Estuaries and Lagoons. CRC Press, Boca Raton, Florida.

Kalff, J. 2002. Limnology. Prentice Hall. Upper Saddle River, New Jersey.

Patton, C.J., and J.R. Kryskalla. 2003. Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory--evaluation of alkaline persulfate digestion as an alternative to Kjeldahl digestion for determination of total and dissolved nitrogen and phosphorus in water: U.S. Geological Survey Water-Resources Investigations Report 03- 4174, 33 p.

Poirrier, M.A., K. Burt-Utley, J.F. Utley, E.A. Spalding. 2009. An Inventory and Assessment of the Distribution of Submersed Aquatic Vegetation at Jean Lafitte National Historical Park and Preserve, New Orleans, April 2009.

Poirrier, M.A., K. Burt-Utley, J.F. Utley, E.A. Spalding. 2010. Submersed Aquatic Vegetation of the Jean Lafitte National Historical Park and Preserve. Southeastern Naturalist 9:487-486.

Schultz, D.L. 2006. A Survey and Analysis of the Fish Fauna of the Barataria Preserve of Jean Lafitte National Park. Department of Biological Sciences, Nicholls State University.

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Swarzenski, C.M., S.V. Mize, B.A. Thompson, and G.W. Peterson. 2004. Fish and aquatic invertebrate communities in waterways, and contaminants in fish, at the Barataria Preserve of Jean Lafitte National Historical Park and Preserve, Louisiana, 1999–2000. U.S. Geological Survey, Baton Rouge, LA. 35 pp.

U.S. Environmental Protection Agency (USEPA). 2006a. Guidance on Systematic Planning Using the Data Quality Objectives Process. EPA QA/G-4. EPA/240/B-06/001. U.S. Environmental Protection Agency, Office of Environmental Information, Washington, D.C.

USEPA. 2006b. Guidance for Data Quality Assessment: Practical Methods for Data Analysis. EPA QA/G-9. EPA/240/B-06/003. U.S. Environmental Protection Agency, Office of Environmental Information, Washington, DC.

Weston Solutions 2011. Deepwater Horizon/Mississippi Canyon 252 Oil Spill Report on Submerged Aquatic Vegetation Residing in Jean Lafitte National Historic Park and Preserve, Natural Resource Damage Assessment Draft Report. Prepared for National Park Service. March 2011.

Wetzel, R.G. 2001. Limnology: Lake and River Ecosystems. San Diego, Academic Press.

Zar, J.H. 1999. Biostatistical analysis. 4th edition. Prentice Hall, Upper Saddle River, NJ.

Zimmerman, C.F., C.W. Keefe, and J. Bashe. 1997. Method 440.0 Determination of Carbon and Nitrogen in Sediments and Particulates of Estuarine/Coastal Waters Using Elemental Analysis. National Exposure Research Laboratory, Office of Research and Development, USEPA. Revision 1.4. September 1997.

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APPENDIX A

JELA and Reference Station Photographs (Provided as a Separate Document)

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APPENDIX B

Physical & Chemical Water Quality

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Water Quality Measurements and Conditions during Spring 2011 Survey at JELA Stations

Secchi Irradiance pH Water Sediment Max. Salinity Water Conductance DO Turbidity Weather Station Time Date Latitude Longitude Depth (Bottom) (pH Total Total Total Total Depth (ppt) Temp.(ºC) (mS/cm) (mg/L) (NTU) Cloud Cover (m) mol/s/m2) units) Nitrogen Phosphorus Nitrogen Phosphorus (m) (mg/L) (mg/L) (%) (%) 1 14:22 5/17/2011 29.86354 -90.16579 0.50 0.40 0.33 26.0 0.678 219.3 7.6 8.70 66.0 Sunny, clear 1.34 0.2931 0.39 0.1063 2 16:25 5/16/2011 29.83478 -90.15471 1.42 0.80 0.32 26.5 0.670 87.6 8.58 8.56 2.7 Sunny, breezy 1.08 0.0507 0.92 0.0868 3 9:30 5/20/2011 29.82387 -90.12334 3.00 0.10 0.35 23.3 0.720 0.0 1.4 7.84 6.1 Partly cloudy 2.22 0.1713 1.29 0.0853 4 14:05 5/18/2011 29.77156 -90.14011 1.30 0.60 0.62 27.8 0.006 45.3 7.02 7.95 23.1 Sunny, clear 1.32 0.1119 1.57 0.0378 5 9:57 5/19/2011 29.77386 -90.11121 0.45 0.10 1.01 22.7 1.974 0.0 2.13 8.12 63.1 Mostly cloudy 3.47 0.3666 1.13 0.0873 6 10:53 5/18/2011 29.74235 -90.14192 0.85 0.35 0.23 25.4 0.456 11.5 8.46 8.68 45.3 Sunny, clear 1.56 0.1426 0.20 0.0787 7 11:21 5/16/2011 29.79624 -90.16225 1.30 0.50 0.25 24.1 0.500 44.3 8.38 8.61 19.8 Sunny, breezy 0.91 0.1102 0.39 0.0782 8 13:07 5/16/2011 29.84078 -90.16879 0.60 0.32 0.18 25.6 0.394 1687.7 11.17 8.92 2.5 Sunny, breezy Not sampled Not sampled 9 14:50 5/16/2011 29.81842 -90.16361 0.85 0.25 0.29 26.1 0.559 4.6 7.48 8.39 66.3 Sunny, breezy 1.36 0.1821 1.19 0.0602 10 12:08 5/17/2011 29.84347 -90.19173 0.60 0.36 0.30 22.7 0.624 276.0 6.34 8.59 41.0 Sunny, clear 0.84 0.1033 0.13 0.0693 11 17:26 5/19/2011 29.84435 -90.14758 1.10 0.27 0.30 26.7 0.630 0.0 8.25 8.38 6.8 Mostly cloudy Not sampled Not sampled 12 16:26 5/18/2011 29.84779 -90.14344 0.76 0.70 0.32 26.8 0.668 8.1 5.89 7.76 10.3 Partly cloudy Not sampled Not sampled 13 15:10 5/19/2011 29.84396 -90.15648 0.70 0.40 0.33 28.6 0.694 383.1 7.65 8.50 26.9 Partly cloudy 1.06 0.1388 0.62 0.1684 14 11:30 5/20/2011 29.81379 -90.12727 1.24 0.72 0.31 26.4 0.641 622.3 5.91 7.53 8.9 Partly cloudy Not sampled 15 8:21 5/20/2011 29.78842 -90.13806 0.75 0.30 0.32 24.8 0.657 0.0 4.7 7.85 28.9 Mostly cloudy 2.12 0.2253 1.77 0.0800 16 14:46 5/20/2011 29.78867 -90.07484 0.89 0.30 0.17 26.4 0.367 23.9 8.13 8.14 44.3 Mostly cloudy Not sampled Not sampled 17 13:55 5/20/2011 29.77729 -90.07274 1.35 1.00 0.31 25.7 0.635 89.3 4.89 7.82 4.5 Partly cloudy Not sampled Not sampled 18 9:06 5/19/2011 29.76842 -90.10723 0.70 0.23 1.11 21.8 2.163 33.9 8.81 8.40 11.4 Sunny Not sampled Not sampled 19 15:14 5/18/2011 29.78685 -90.13630 0.75 0.40 0.73 26.0 1.453 62.6 5.6 8.23 35.4 Sunny Not sampled Not sampled 20 12:56 5/20/2011 29.78616 -90.08916 1.30 0.78 0.28 26.6 0.575 527.6 6.17 7.85 12.0 Partly cloudy Not sampled Not sampled 21 9:14 5/18/2011 29.75726 -90.15395 1.00 0.25 0.25 22.9 0.522 26.4 8.9 8.81 55.5 Sunny, clear Not sampled Not sampled 22 9:36 5/17/2011 29.86864 -90.23616 0.40 0.30 0.23 21.8 0.485 735.9 7.49 9.13 22.3 Sunny 1.05 0.1062 1.18 0.0953 23 10:43 5/17/2011 29.86177 -90.21815 0.65 0.40 0.13 22.9 0.272 466.6 8.07 8.77 24.1 Sunny, clear Not sampled Not sampled 24 13:32 5/17/2011 29.83181 -90.18126 0.70 0.40 0.28 24.4 0.581 252.0 6.51 8.47 48.9 Sunny, clear Not sampled Not sampled 25 16:35 5/18/2011 29.80824 -90.12653 1.00 0.55 0.40 25.6 0.810 311.2 7.05 8.47 53.5 Sunny, clear Not sampled Not sampled 26 14:06 5/19/2011 29.84264 -90.17279 0.63 0.30 0.29 26.5 0.603 116.7 7.87 7.51 35.4 Mostly cloudy Not sampled Not sampled 27 10:10 5/18/2011 29.74563 -90.15242 1.50 0.30 0.25 23.4 0.521 22.0 9.01 8.64 60.8 Sunny, clear Not sampled Not sampled 28 9:29 5/16/2011 29.80524 -90.15745 0.60 0.37 0.26 22.2 0.542 156.5 10.12 8.57 1.6 Sunny, breezy Not sampled Not sampled 29 13:06 5/18/2011 29.78042 -90.14998 0.77 0.30 0.27 27.3 0.009 206.4 8.84 7.94 37.6 Sunny, clear 1.08 0.1099 0.79 0.0758 30 11:53 5/18/2011 29.76067 -90.14577 0.65 0.30 0.25 25.8 0.521 105.8 8.75 8.56 33.5 Sunny, clear Not sampled Not sampled 31 15:50 5/16/2011 29.83230 -90.16580 0.70 0.36 0.29 26.6 0.610 316.4 7.21 8.53 33.9 Sunny, breezy Not sampled Not sampled 32 12:19 5/16/2011 29.80437 -90.18497 0.70 0.66 0.25 23.5 0.524 1041.3 9.99 8.98 2.5 Sunny, breezy Not sampled Not sampled 33 14:05 5/16/2011 29.81695 -90.17032 0.60 0.38 0.35 26.2 0.715 768.8 12.01 8.92 1.6 Sunny, breezy Not sampled Not sampled 34 17:30 5/16/2011 29.83380 -90.15257 1.10 0.95 0.30 29.6 0.630 84.3 90.75 8.79 1.2 Sunny, breezy Not sampled Not sampled 35 15:23 5/17/2011 29.85024 -90.17355 0.75 0.42 0.32 24.9 0.651 105.4 8.54 8.34 21.2 Sunny, clear Not sampled Not sampled 36 12:48 5/17/2011 29.84249 -90.18963 0.55 0.20 0.37 23.7 0.413 1072.3 6.33 7.96 58.2 Sunny, clear Not sampled Not sampled 37 10:33 5/20/2011 29.82749 -90.13341 1.40 0.50 0.32 26.1 0.652 26.1 3.53 7.85 32.4 Mostly cloudy Not sampled Not sampled

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Secchi Irradiance pH Water Sediment Max. Salinity Water Conductance DO Turbidity Weather Station Time Date Latitude Longitude Depth (Bottom) (pH Total Total Total Total Depth (ppt) Temp.(ºC) (mS/cm) (mg/L) (NTU) Cloud Cover (m) mol/s/m2) units) Nitrogen Phosphorus Nitrogen Phosphorus (m) (mg/L) (mg/L) (%) (%) 38 11:26 5/17/2011 29.86320 -90.86320 1.05 0.50 0.30 22.5 0.618 48.3 5.47 8.45 60.7 Sunny, clear Not sampled Not sampled 39 12:50 5/19/2011 29.82414 -90.16322 0.75 0.47 0.30 25.3 0.624 255.6 7.44 7.50 19.1 50% cloudy 0.94 0.1279 0.80 0.0894

Water Quality Measurements and Conditions during Spring 2011 Survey at Reference Stations Secch Irradiance Water Sediment Water pH Max. i Salinity Conductance (Bottom) DO Turbidity Weather Station Time Date Latitude Longitude Temp (pH Total Total Total Total Depth Depth (ppt) (mS/cm) mol/s/m (mg/L) (NTU) Cloud Cover (ºC) units) Nitrogen Phosphorus Nitrogen Phosphorus (m) (m) 2) (mg/L) (mg/L) (mg/L) (%) R1 10:48 5/21/2011 29.85938 -90.47208 0.76 0.47 0.40 28.0 0.812 368.8 7.22 8.11 14.8 Mostly sunny 1.29 0.1302 0.47 0.0750 R2 13:02 5/21/2011 29.85766 -90.48676 1.25 0.50 0.50 27.4 1.019 346.0 7.37 8.03 16.0 40% cloudy 0.91 0.0843 0.12 0.0534 R3 14:05 5/21/2011 29.84702 -90.48392 0.86 0.45 0.49 28.5 1.000 664.9 7.20 8.26 25.6 40% cloudy 3.06 0.3388 1.14 0.0788 R4 12:00 5/21/2011 29.86501 -90.46887 1.64 0.95 0.27 27.4 0.569 211.8 6.31 7.88 2.4 40% cloudy 2.35 0.2574 0.78 0.0536 R5 9:43 5/21/2011 29.85661 -90.46104 0.90 0.60 0.27 27.1 0.557 169.5 6.31 8.14 8.9 Mostly sunny 1.23 0.1191 0.50 0.0582

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MC 252 Oil Spill – Jean Lafitte National Historic Park and Preserve Submerged Aquatic Vegetation NRDA Spring 2011 Draft Report February 2012

Water Quality Measurements and Conditions during Fall 2011 Survey at JELA Stations

Secchi Irradiance pH Water Sediment Max. Salinity Water Conductance DO Turbidity Weather Station Time Date Latitude Longitude Depth (Bottom) (pH Total Total Total Total Depth (ppt) Temp.(ºC) (mS/cm) (mg/L) (NTU) Cloud Cover (m) mol/s/m2) units) Nitrogen Phosphorus Nitrogen Phosphorus (m) (mg/L) (mg/L) (%) (%) 1 1522 9/12/2011 29.86361 -90.16576 0.69 0.30 0.25 29.62 0.516 39.5 5.75 7.21 27.8 Sunny, clear 1.36 0.10 0.98 0.18 2 1330 9/15/2011 29.83456 -90.15472 1.06 0.20 0.31 29.75 0.646 0.4 5.81 7.02 5.5 Partly Cloudy, breezy 1.70 0.21 1.07 0.05 3 1006 9/15/2011 29.82378 -90.1232 1.72 0.20 0.22 23.92 0.466 0 1.82 6.2 45.8 Sunny, clear 12.13 1.58 1.48 0.07 4 857 9/16/2011 29.77141 -90.14043 0.33 0.33 0.73 25.32 1.452 82.06 1.84 6.72 1.3 Sunny, clear 1.43 0.08 1.04 0.06 5 1240 9/16/2011 29.77394 -90.11135 0.87 0.08 0.74 24.49 1.48 0 1.65 6.21 80 Sunny, clear 4.07 0.26 1.12 0.07 6 1622 9/14/2011 29.74207 -90.14189 0.66 0.40 1.19 30.64 2.335 30.2 6.67 7.19 20.1 Sunny, clear 1.15 0.13 0.32 0.08 7 1504 9/13/2011 29.79633 -90.16223 1.40 0.40 1.86 32.73 3.584 36.65 9.37 7.88 9.2 Sunny, clear 1.05 0.11 0.20 0.09 8 1310 9/13/2011 29.80504 -90.16858 0.43 0.32 1.32 30.51 2.589 843.6 8.3 7.78 20.5 Sunny, clear Not sampled Not sampled 9 1120 9/13/2011 29.81852 -90.16344 0.61 0.45 0.79 28.77 1.577 643.2 5.5 7.19 20.1 Sunny, clear 1.23 0.14 0.68 0.05 10 1307 9/12/2011 29.84332 -90.19154 0.74 0.39 0.31 28.99 0.643 378.9 10.32 8.43 30.3 Sunny, clear 1.05 0.11 1.20 0.07 11 1440 9/15/2011 29.84451 -90.14774 0.66 0.36 0.25 29.87 0.522 130.48 3.18 6.64 14 Sunny, clear, breezy Not sampled Not sampled 12 1558 9/15/2011 29.84799 -90.14327 1.41 0.20 0.25 28.41 0.157 0.74 2.07 6.9 13.9 Sunny, clear Not sampled Not sampled 13 1020 9/14/2011 29.84394 -90.1563 0.64 0.30 0.26 27.97 0.544 99.61 3.81 7.16 85.1 Sunny, clear 8.63 0.48 0.54 0.16 14 855 9/15/2011 29.81419 -90.12733 0.86 0.56 0.31 25.33 0.65 43.52 0.61 6.57 67.4 Partly Cloudy, breezy Not sampled Not sampled 15 1011 9/16/2011 29.7884 -90.13784 0.74 0.59 0.59 24.59 1.187 40.8 1.75 6.47 3.5 Sunny, clear 4.15 0.28 1.52 0.09 16 1623 9/16/2011 29.78812 -90.07496 0.56 0.20 0.24 25.56 0.509 10.57 1.61 6.61 37.7 Sunny, clear Not sampled Not sampled 17 1427 9/16/2011 29.77728 -90.07264 0.73 0.20 0.26 26.51 0.545 0 1.5 6.42 39 Sunny, clear Not sampled Not sampled 18 1137 9/16/2011 29.7684 -90.10713 0.30 0.12 0.85 24.95 1.676 188.96 4.73 6.85 3.6 Sunny, clear Not sampled Not sampled 19 805 9/16/2011 29.78644 -90.1364 0.61 0.36 0.58 23.3 1.163 54.08 1.67 6.72 16.9 Partly Cloudy Not sampled Not sampled 20 1526 9/16/2011 29.78609 -90.08839 0.94 0.22 0.19 28.64 0.402 0 0.86 6.79 34.3 Sunny, clear Not sampled Not sampled 21 900 9/14/2011 29.75728 -90.15394 1.44 0.25 2.78 28.22 5.19 173.5 5.14 7.56 36.4 Sunny, clear Not sampled Not sampled 22 1107 9/12/2011 29.86884 -90.2363 0.53 0.23 0.27 29.32 0.557 532.1 5.11 7.9 27.3 Sunny, Clear 86oF 1.40 0.21 0.58 0.07 23 1215 9/12/2011 29.86171 -90.2179 0.71 0.40 0.29 29.83 0.61 1105.6 9.76 8.05 14 Sunny, Clear Not sampled Not sampled 24 1424 9/12/2011 29.83166 -90.18122 0.48 0.40 0.31 32.58 0.658 530.2 11.62 8.54 8.4 Sunny, Clear Not sampled Not sampled 25 1652 9/15/2011 29.80834 -90.12633 0.61 0.50 0.30 29.38 0.631 36.09 3.09 6.77 6 Sunny, Clear Not sampled Not sampled 26 915 9/13/2011 29.84284 -90.17278 0.81 0.44 0.25 26.49 0.517 106.6 7.22 7.33 19.7 Sunny, Clear Not sampled Not sampled 27 812 9/14/2011 29.74566 -90.1525 1.09 0.60 2.80 28.2 5.22 31.81 8.66 7.81 9.1 Sunny, Clear Not sampled Not sampled 28 1315 9/14/2011 29.80511 -90.15745 0.53 0.41 0.52 30.72 1.068 179.91 8.09 7.52 29.1 Sunny, Clear Not sampled Not sampled 29 1513 9/14/2011 29.78032 -90.1499 0.66 0.33 0.79 32.69 1.588 353.5 8.92 7.47 26 Sunny, Clear 1.12 0.12 0.92 0.05 30 1417 9/14/2011 29.7606 -90.14571 0.84 0.42 1.15 29.53 2.262 43.19 5.22 7.06 17.5 Sunny, Clear Not sampled Not sampled 31 1015 9/13/2011 29.83224 -90.1659 0.81 0.30 0.32 28.36 0.662 43.03 6.62 7.47 45.8 Sunny, Clear Not sampled Not sampled 32 1425 9/13/2011 29.80442 -90.18501 0.94 0.33 2.86 32.35 5.37 69 9.9 8.3 16.3 Sunny, Clear Not sampled Not sampled 33 1224 9/13/2011 29.81706 -90.17032 0.81 0.38 0.77 29.92 1.546 396.6 5.24 7.78 19.5 Sunny, Clear Not sampled Not sampled 34 1220 9/15/2011 29.83337 -90.15176 0.46 0.33 0.27 30.11 0.558 93.05 4.5 7.07 1.9 Sunny, Clear Not sampled Not sampled 35 834 9/13/2011 29.8504 -90.17364 0.99 0.40 0.25 27.32 0.52 22.62 7.06 7.93 9.6 Sunny, Clear Not sampled Not sampled 36 1349 9/12/2011 29.8426 -90.18961 0.30 0.25 0.31 31.94 0.641 531.8 11.42 8.61 19.8 Sunny, Clear Not sampled Not sampled 37 1117 9/15/2011 29.82749 -90.13313 1.34 0.60 0.31 28.44 0.642 23.02 1.1 6.57 2 Sunny, clear, breezy Not sampled Not sampled

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MC 252 Oil Spill – Jean Lafitte National Historic Park and Preserve Submerged Aquatic Vegetation NRDA Spring 2011 Draft Report February 2012

Secchi Irradiance pH Water Sediment Max. Salinity Water Conductance DO Turbidity Weather Station Time Date Latitude Longitude Depth (Bottom) (pH Total Total Total Total Depth (ppt) Temp.(ºC) (mS/cm) (mg/L) (NTU) Cloud Cover (m) mol/s/m2) units) Nitrogen Phosphorus Nitrogen Phosphorus (m) (mg/L) (mg/L) (%) (%) 38 945 9/12/2011 29.86318 -90.20287 0.41 0.18 0.36 26.18 0.743 470.8 5.66 6.96 24 Sunny, Clear Not sampled Not sampled 39 1150 9/14/2011 29.82416 -90.16325 0.73 0.53 0.40 29.66 0.831 299 5.48 7.43 40.3 Sunny, Clear 2.20 0.07 0.87 0.11

Water Quality Measurements and Conditions during Fall 2011 Survey at Reference Stations Secch Water Sediment Water Irradiance pH Max. i Salinity Conductance DO Turbidity Weather Station Time Date Latitude Longitude Temp (Bottom) (pH Total Total Total Total Depth Depth (ppt) (mS/cm) (mg/L) (NTU) Cloud Cover (ºC) (mol/s/m2) units) Nitrogen Phosphorus Nitrogen Phosphorus (m) (m) (mg/L) (mg/L) (%) (%) R1 1125 9/17/2011 29.8593 -90.47186 0.51 25 0.30 26.37 0.623 272.2 2.36 6.92 1.2 Partly cloudy 1.74 0.30 0.45 0.09 R2 1344 9/17/2011 29.85784 -90.48682 0.79 40 0.19 27.95 0.396 95.72 1.26 7.03 8.3 Partly cloudy 1.42 0.19 0.72 0.04 R3 1438 9/17/2011 29.84712 -90.48373 1.02 60 0.36 23.8 0.746 409.2 1.21 6.19 17.5 Partly cloudy 1.27 0.04 1.12 0.08 R4 1232 9/17/2011 29.86506 -90.46875 0.91 45 0.31 26.14 0.634 1.4 1.42 6.48 9.8 Partly cloudy 1.63 0.12 1.37 0.08 R5 1008 9/17/2011 29.85662 -90.4604 0.74 60 0.3 25.77 0.628 7.5 2.9 6.8 1.3 Partly cloudy 1.57 0.22 0.65 0.08

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APPENDIX C

Submerged & Floating Aquatic Vegetation

This Page Intentionally Blank MC 252 Oil Spill – Jean Lafitte National Historic Park and Preserve Submerged Aquatic Vegetation NRDA Spring 2011 Draft Report February 2012

Observed Submerged Aquatic Vegetation and Floating Aquatic Vegetation Coverage at JELA during Spring 2011 Survey Floating Max. Submerged Aquatic Vegetation Species Salvinia Aquatic Station Time Date Latitude Longitude Depth SAV molesta C. C. H. N. V. H. E. E. Coverage Vegetation Coverage (m) M. spicatum P. pusillus demersum caroliniana verticillata guadalupensis americana dubia canadensis densa (%) Coverage (%) (%) 1 14:22 5/17/2011 29.86354 -90.16579 0.50 x x x 3.8 0.0 0.0 2 16:25 5/16/2011 29.83478 -90.15471 1.42 x x x x 55.0 46.3 37.5 3 9:30 5/20/2011 29.82387 -90.12334 3.00 0.0 100.0 95.3 4 14:05 5/18/2011 29.77156 -90.14011 1.30 x x x 22.8 10.0 2.9 5 9:57 5/19/2011 29.77386 -90.11121 0.45 0.0 100.0 93.5 6 10:53 5/18/2011 29.74235 -90.14192 0.85 x x 28.0 0.0 0.0 7 11:21 5/16/2011 29.79624 -90.16225 1.30 0.0 0.0 0.0 8 13:07 5/16/2011 29.84078 -90.16879 0.60 x x x x x x x 32.5 0.1 0.0 9 14:50 5/16/2011 29.81842 -90.16361 0.85 x x x x x x x 16.3 0.0 0.0 10 12:08 5/17/2011 29.84347 -90.19173 0.60 x 0.1 0.0 0.0 11 17:26 5/19/2011 29.84435 -90.14758 1.10 x x x x x 80.0 95.8 93.5 12 16:26 5/18/2011 29.84779 -90.14344 0.76 x x x x x 32.5 80.0 76.5 13 15:10 5/19/2011 29.84396 -90.15648 0.70 x x x x x x x 32.5 43.0 22.1 14 11:30 5/20/2011 29.81379 -90.12727 1.24 x x x x x x 13.0 35.8 29.3 15 8:21 5/20/2011 29.78842 -90.13806 0.75 x x x x 100.0 11.4 0.5 16 14:46 5/20/2011 29.78867 -90.07484 0.89 x x x x x x 66.3 60.0 1.3 17 13:55 5/20/2011 29.77729 -90.07274 1.35 x x x x 95.0 85.0 0.0 18 9:06 5/19/2011 29.76842 -90.10723 0.70 x x x x 68.8 8.0 0.0 19 15:14 5/18/2011 29.78685 -90.13630 0.75 x x x x 38.8 30.0 9.3 20 12:56 5/20/2011 29.78616 -90.08916 1.30 x x x x x 76.3 48.8 0.9 21 9:14 5/18/2011 29.75726 -90.15395 1.00 x 7.5 0.3 0.0 22 9:36 5/17/2011 29.86864 -90.23616 0.40 x x 0.3 0.0 0.0 23 10:43 5/17/2011 29.86177 -90.21815 0.65 x 1.0 0.0 0.0 24 13:32 5/17/2011 29.83181 -90.18126 0.70 x 0.1 0.0 0.0 25 16:35 5/18/2011 29.80824 -90.12653 1.00 x x 14.5 21.3 17.8 26 14:06 5/19/2011 29.84264 -90.17279 0.63 x x x x 8.3 37.8 1.3 27 10:10 5/18/2011 29.74563 -90.15242 1.50 x 13.0 0.4 0.0 28 9:29 5/16/2011 29.80524 -90.15745 0.60 x x x x x x 88.8 34.3 1.6 29 13:06 5/18/2011 29.78042 -90.14998 0.77 x x x x x 38.0 0.1 0.0 30 11:53 5/18/2011 29.76067 -90.14577 0.65 x x x x x 77.5 3.4 0.4 31 15:50 5/16/2011 29.83230 -90.16580 0.70 x x x x x 2.0 0.0 0.0 32 12:19 5/16/2011 29.80437 -90.18497 0.70 x x x 27.5 0.0 0.0 33 14:05 5/16/2011 29.81695 -90.17032 0.60 x x x x x x 75.0 0.9 0.1 34 17:30 5/16/2011 29.83380 -90.15257 1.10 x x x x x x 87.5 40.0 28.8 35 15:23 5/17/2011 29.85024 -90.17355 0.75 0.0 0.0 0.0 36 12:48 5/17/2011 29.84249 -90.18963 0.55 x 0.5 0.0 0.0 37 10:33 5/20/2011 29.82749 -90.13341 1.40 x x x x x 5.5 66.3 51.3 38 11:26 5/17/2011 29.86320 -90.86320 1.05 0.0 0.0 0.0

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MC 252 Oil Spill – Jean Lafitte National Historic Park and Preserve Submerged Aquatic Vegetation NRDA Spring 2011 Draft Report February 2012

Floating Max. Submerged Aquatic Vegetation Species Salvinia Aquatic Station Time Date Latitude Longitude Depth SAV molesta C. C. H. N. V. H. E. E. Coverage Vegetation Coverage (m) M. spicatum P. pusillus demersum caroliniana verticillata guadalupensis americana dubia canadensis densa (%) Coverage (%) (%) 39 12:50 5/19/2011 29.82414 -90.16322 0.75 x x x x x x 12.9 17.8 25.0

Observed Submerged Aquatic Vegetation and Floating Aquatic Vegetation Coverage at Reference Stations during Spring 2011 Survey Floating Max. Submerged Aquatic Vegetation Species Salvinia Aquatic Station Time Date Latitude Longitude Depth SAV molesta C. C. H. N. V. H. E. E. Coverage Vegetation Coverage (m) M. spicatum P. pusillus demersum caroliniana verticillata guadalupensis americana dubia canadensis densa (%) Coverage (%) (%) R1 10:48 5/21/2011 29.85938 -90.47208 0.76 x 0.6 55.0 38.3 R2 13:02 5/21/2011 29.85766 -90.48676 1.25 0.0 23.8 17.5 R3 14:05 5/21/2011 29.84702 -90.48392 0.86 x x x 0.4 33.8 22.5 R4 12:00 5/21/2011 29.86501 -90.46887 1.64 0.0 89.5 85.5 R5 9:43 5/21/2011 29.85661 -90.46104 0.90 x 0.1 57.5 52.5

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MC 252 Oil Spill – Jean Lafitte National Historic Park and Preserve Submerged Aquatic Vegetation NRDA Spring 2011 Draft Report February 2012

Observed Submerged Aquatic Vegetation and Floating Aquatic Vegetation Coverage at JELA Stations during Fall 2011 Survey Floating Max. Submerged Aquatic Vegetation Species Salvinia Aquatic Station Time Date Latitude Longitude Depth SAV molesta C. C. H. N. V. H. E. E. Coverage Vegetation Coverage (m) M. spicatum P. pusillus demersum caroliniana verticillata guadalupensis americana dubia canadensis densa (%) Coverage (%) (%) 1 1522 9/12/2011 29.86361 -90.16576 0.69 x x x 22.5 71.25 61.25 2 1330 9/15/2011 29.83456 -90.15472 1.06 x x 1.75 75 68.25 3 1006 9/15/2011 29.82378 -90.1232 1.72 0 100 61.25 4 857 9/16/2011 29.77141 -90.14043 0.33 x x x 3.5 23.75 19.25 5 1240 9/16/2011 29.77394 -90.11135 0.87 x 1.25 100 46.25 6 1622 9/14/2011 29.74207 -90.14189 0.66 x x x x x 32.5 5.25 4 7 1504 9/13/2011 29.79633 -90.16223 1.40 x x x x x 2.5 0 0 8 1310 9/13/2011 29.80504 -90.16858 0.43 x x x x x x 10.75 34.25 24.25 9 1120 9/13/2011 29.81852 -90.16344 0.61 x x x x x 17.5 65 46.25 10 1307 9/12/2011 29.84332 -90.19154 0.74 x 2 0 0 11 1440 9/15/2011 29.84451 -90.14774 0.66 x x x x 29.25 13.25 8.75 12 1558 9/15/2011 29.84799 -90.14327 1.41 0 100 87.5 13 1020 9/14/2011 29.84394 -90.1563 0.64 x x x x 13.75 51.25 36 14 855 9/15/2011 29.81419 -90.12733 0.86 x x x 1.5 46.75 36.25 15 1011 9/16/2011 29.7884 -90.13784 0.74 x x x 33.25 47.5 27.75 16 1623 9/16/2011 29.78812 -90.07496 0.56 x x x x x 71.25 13 6.25 17 1427 9/16/2011 29.77728 -90.07264 0.73 x x x x 26.5 97.5 26.25 18 1137 9/16/2011 29.7684 -90.10713 0.30 x x x 30 22.5 20 19 805 9/16/2011 29.78644 -90.1364 0.61 x x x 6.75 28.75 25 20 1526 9/16/2011 29.78609 -90.08839 0.94 x x x x 67.5 51.25 21.25 21 900 9/14/2011 29.75728 -90.15394 1.44 x x 6.75 8 5.5 22 1107 9/12/2011 29.86884 -90.2363 0.53 x x 1 0.75 0 23 1215 9/12/2011 29.86171 -90.2179 0.71 x 7.75 0 0 24 1424 9/12/2011 29.83166 -90.18122 0.48 x x 4 11.25 0 25 1652 9/15/2011 29.80834 -90.12633 0.61 x x 2.25 43.75 35 26 915 9/13/2011 29.84284 -90.17278 0.81 x x x 16.25 46.25 40.5 27 812 9/14/2011 29.74566 -90.1525 1.09 x 1.75 0.5 0.5 28 1315 9/14/2011 29.80511 -90.15745 0.53 x x x x x 11.5 4.5 4.25 29 1513 9/14/2011 29.78032 -90.1499 0.66 x x x x 11.75 1.75 1.75 30 1417 9/14/2011 29.7606 -90.14571 0.84 x x x 43.75 28 23.125 31 1015 9/13/2011 29.83224 -90.1659 0.81 x x x x x x x x 13.25 21.75 12 32 1425 9/13/2011 29.80442 -90.18501 0.94 x x 4.5 0.5 0.5 33 1224 9/13/2011 29.81706 -90.17032 0.81 x x x x 13.75 2 1 34 1220 9/15/2011 29.83337 -90.15176 0.46 x x x 7.75 31.25 25.25 35 834 9/13/2011 29.8504 -90.17364 0.99 0 0 0 36 1349 9/12/2011 29.8426 -90.18961 0.30 x 0.75 0 0 37 1117 9/15/2011 29.82749 -90.13313 1.34 x x x x 8.25 60.75 41.25 38 945 9/12/2011 29.86318 -90.20287 0.41 x x 6 8.25 0.25

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MC 252 Oil Spill – Jean Lafitte National Historic Park and Preserve Submerged Aquatic Vegetation NRDA Spring 2011 Draft Report February 2012

Floating Max. Submerged Aquatic Vegetation Species Salvinia Aquatic Station Time Date Latitude Longitude Depth SAV molesta C. C. H. N. V. H. E. E. Coverage Vegetation Coverage (m) M. spicatum P. pusillus demersum caroliniana verticillata guadalupensis americana dubia canadensis densa (%) Coverage (%) (%) 39 1150 9/14/2011 29.82416 -90.16325 0.73 x x x x x 15.75 32.25 19

Observed Submerged Aquatic Vegetation and Floating Aquatic Vegetation Coverage at Reference Stations during Fall 2011 Survey Floating Max. Submerged Aquatic Vegetation Species Salvinia Aquatic Station Time Date Latitude Longitude Depth SAV molesta C. C. H. N. V. H. E. E. Coverage Vegetation Coverage (m) M. spicatum P. pusillus demersum caroliniana verticillata guadalupensis americana dubia canadensis densa (%) Coverage (%) (%) R1 1125 9/17/2011 29.8593 -90.47186 0.51 x x x x 6 45 12 R2 1344 9/17/2011 29.85784 -90.48682 0.79 x x x 4.5 26.25 16.25 R3 1438 9/17/2011 29.84712 -90.48373 1.02 x x x x 2 56.25 27.5 R4 1232 9/17/2011 29.86506 -90.46875 0.91 x 0.5 95 39.5 R5 1008 9/17/2011 29.85662 -90.4604 0.74 x x x 1.75 49.25 10.5

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