Seagrass Conservation in Texas Coastal Waters:

Monitoring Design Criteria and Biological Indicators for R-EMAP Region 6

 

 

 

 

 

 

 

 

 

 

 


Table of Contents:

·        Original Proposal

·        Introduction

·        Basemap

·        Data Collected

·        Results/Difficulties Encountered

·        Conclusions

·        References/Acknowledgements

 

 


Introduction

            The Environmental Monitoring and Assessment Program (EMAP) is a research program to develop the tools necessary to monitor and assess the status and trends of the nation ecological resources.  EMAP's primary goal is to develop the scientific understanding to translate environmental monitoring data into assessments of both current trends and forecasts of future risks to our natural resources.  REMAP (Regional – EMAP) was initiated to test the applicability of the EMAP approach to answer questions about ecological conditions at smaller geographic scales and shorter time frames. The map below shows how the REMAP regions are divided.  Texas is located in region 6. 

 

The EPA lists specific several objectives for REMAP:

  1. Evaluate and improve EMAP concepts for state and local use
  2. Assess the applicability of EMAP indicators at differing spatial scales
  3. Demonstrate the utility of EMAP for resolving issues of importance to EPA Regions and states.

 
 

 

 

            This REMAP project will develop indicators and criteria that will be used in a future long-term seagrass monitoring plan for the State of Texas.  This includes specific studies to measure the effectiveness of various indicators to monitor seagrasses for management and conservation.  Determining the optimum spatial and temporal sampling frequency of these indicators will be included in the study.

 

 

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Basemap

            The study that I am doing my term project on was started last year with the creation of the basemap.  Andrea Kopecky, a marine science graduate student in Dr. Kenneth Dunton’s laboratory, worked with Jon Goodall, a graduate research assistant for Dr. David Maidment, worked together to create the basemap as well as to implement the sampling design into the map.  The map was created using data from the National Hydrography Dataset (NHD), Digital Raster Graphs (DRG’s) from the Texas National Resource Information System (TNRIS), and Digital Orthophoto Quadrangles (DOQ’s).  The DRG’s are in Universal Transverse Mercator (UTM) coordinates.  The two site locations are shown on the map below.

 

Redfish Bay
 

Study Locations
 

Lower Laguna Madre
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 


            Selection of sampling sites followed the procedures outlined by the EPA.  The Theissen function in ArcWorkstation was used to create the hexagons.  Each area (Redfish Bay and Lower Laguna Madre) was divided into 60+ hexagons.  A random sample generator was used to create 60 site locations within each hexagon (30 base sites and 30 alternate sites).  The probability of having a site within a particular hexagon depended on how much the hexagon was covered with water.  Under this design, each hexagon will have no more than one site and some hexagons will not have any sites. 

 

Detail of Sampling Design:
 

 

 

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Data Collected

When was the data collected?

            The data for this project was collected in Redfish Bay during the month of August.  Seven field days total were needed to sample all thirty locations in Redfish Bay.

 

What was collected?

 
Depth measurements

Physiochemical Parameters (salinity, conductivity, dissolved oxygen, temperature)

Total Suspended Solids/Light Attenuation

Nutrients (NH4, NO3, NO2)

Chlorophyll (phytoplankton biomass)

Drift Algae along a 50-m transect

Seagrass Biomass

% Cover of Seagrasses along a 50-m transect

 

This translated into a lot of data (from both RFB and LLM)!

Up to 900 bags of biomass cores

600 bags of algae

540 water samples each for

Total Suspended Solids

Dissolved Inorganic Nitrogen

Chlorophyll

 

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Results/Difficulties Encountered

            Before I could analyze any of the data in GIS, I needed to get the data into a workable format in excel sheets.  All of the different parameters were associated with a particular EMAP-ID and each EMAP-ID had a set of X, Y coordinates.  To start with a reasonable limit, I only analyzed the depth, salinity, TSS, light attenuation, chlorophyll, and (once they because available) nutrient data (specifically NH4).  Once the data were entered into excel spreadsheets they were saved as database files, added to the map and saved as shapefiles.  This procedure was done for each of the parameters that I analyzed.  The following five pictures show the initial results from adding the data onto the map. 

 
 

 
1.                                                                                                     2.

 

 
 

 
3.                                                                                                    4.

 

 

5.

 

 

 

            These maps are good because they provide an easy way to see the spatial distribution of the data.  However, kriging tools are available to make the possible trends more visible.  I spent some time exploring with that tool and here are the maps again after using the kriging tool in the spatial analyst bar in ArdHydro.

 

 

 
 
 


 

 

            I did have some problems with the presentation of these maps.  The basemap used several different layers to create the detailed islands in the map above.  Because of this, water and land sections are not simply in two different layers.  When I added the chlorophyll data to the basemap I was unable to use GIS to view the data.  The map looked like the diagram below.

 

 

 

 

            This made it difficult to see any of the specific trends because you could not tell the difference between upper and lower Redfish Bay.  It was difficult to tell where the water began and the land ended.  To fix the problem for the term project I ended up editing all of the pictures in Adobe Photoshop to create the layers I wanted.  It was very time consuming and so it would be much easier if another method could be used in GIS. 

 

 

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Conclusions

            This term project focused on using the GIS tools to analyze data collected from the EPA REMAP study.  A huge amount of data will be collected over the next two years for this experiment and GIS tools provide an easy, effective way to examine the data.  Patterns of the physiochemical parameters that I focused on can be examined over time to analyze what is going on in the seagrass beds.  This REMAP study is trying to determine which criteria will be useful in long-term monitoring studies and GIS is the tool that will help in the analysis.  GIS is able to show more information in one picture then multiple tables or graphs.  It is a very useful tool in ecological data analysis.

 

 

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References/Acknowledgements

Dunton, K. H., and D. R. Maidment.  2002.  Regional environmental and monitoring assessment program R-EMAP-Region 6: Monitoring design criteria

and biological indicators for seagrass conservation in Texas coastal waters.  UTMSI proposal number 2660-0141.

 

Environmental Protection Agency.  http://www.epa.gov/nerleerd/emapremap.htm

 

Thanks to…

Andrea Kopecky and Dr. Kenneth Dunton, University of Texas Marine Science Institute

Jon Goodall and Dr. David Maidment

 

 

 

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