Marine Resources Assessment for the Marianas Operating ... - SPREP
Marine Resources Assessment for the Marianas Operating ... - SPREP
Marine Resources Assessment for the Marianas Operating ... - SPREP
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AUGUST 2005 FINAL REPORT<br />
ESRI's proprietary macro-language, to automate <strong>the</strong> more repetitive map-making tasks as well as <strong>the</strong><br />
processing and analysis of large volumes of data.<br />
1.4.2.1 Maps of <strong>the</strong> Physical Environment⎯Oceanography and Habitats<br />
Bathymetric data from Sandwell et al. (2004) were sampled at 2 minute (min) resolution and were<br />
acquired as geographic coordinates giving depth below mean sea level. Depth data were imported into<br />
<strong>the</strong> Spatial Analyst module of ArcView ® , which interpolated and contoured <strong>the</strong> data at 50 m intervals <strong>for</strong><br />
waters shallower than 100 m and at 500 m intervals <strong>for</strong> waters deeper than 500 m. Selected isobaths<br />
from <strong>the</strong> resulting two-dimensional contours are shown on <strong>the</strong> bathymetry figures and on various maps<br />
throughout <strong>the</strong> MRA report.<br />
To illustrate <strong>the</strong> three-dimensional (3D) bathymetry of <strong>the</strong> <strong>Marianas</strong> MRA study area, triangular irregular<br />
networks (TINs), which interpolate intermediate data values between surveyed data points, were created<br />
using <strong>the</strong> available bathymetry data and processing those data in <strong>the</strong> ArcGIS ® 3D Analyst extension. The<br />
2 min bathymetric sounding data sampled from Sandwell et al. (2004) were used to create <strong>the</strong> TIN, which<br />
depicts <strong>the</strong> 3D bathymetry of <strong>the</strong> study area (Figures 2-1 and 2-4). The TINs were viewed in <strong>the</strong> ArcGIS ®<br />
8.3 ArcScene extension to model <strong>the</strong> 3D display. ArcScene ® allows <strong>the</strong> 3D display to be manipulated<br />
(i.e., rotated, tilted, zoomed, classified, and overlaid with data). The most au<strong>the</strong>ntic display was exported<br />
directly from an ArcScene ® view as a graphic file (.tif), which was <strong>the</strong>n imported into ArcView ® <strong>for</strong> <strong>the</strong> final<br />
map layout.<br />
Seasonal averages of sea surface temperature (SST) were obtained from <strong>the</strong> NASA and compiled from<br />
weekly averaged Advanced Very High-resolution Radiometer (AVHRR) images, which contain multichannel<br />
sea surface temperature (MCSST) pixel data <strong>for</strong> <strong>the</strong> years 1981 to 2001. Seasonal averages of<br />
chlorophyll a (chl a) concentrations were also obtained from <strong>the</strong> NASA and compiled from monthly<br />
averaged Coastal Zone Color Scanner (CZCS) images taken from 1978 to 1986 to provide a proxy of<br />
primary productivity <strong>for</strong> <strong>the</strong> study area. Seasons were defined with <strong>the</strong> same monthly derivations used<br />
throughout <strong>the</strong> MRA report (dry=December through June, rainy=July through November).<br />
Multiple sources of data and in<strong>for</strong>mation were used in <strong>the</strong> creation of maps <strong>for</strong> <strong>the</strong> oceanic and coastal<br />
habitats located in <strong>the</strong> <strong>Marianas</strong> MRA study area and vicinity. The maps displaying benthic communities,<br />
chemosyn<strong>the</strong>tic communities, and artificial habitats (Figures 2-3, 2-13, and 2-14) are good examples of<br />
multiple data sources used in <strong>the</strong> creation of a single map. These maps were created using scanned<br />
images, coordinate data, GIS shapefiles, and o<strong>the</strong>r in<strong>for</strong>mation available in <strong>the</strong> scientific literature and<br />
technical reports.<br />
1.4.2.2 Biological Resource Maps⎯Species of Concern<br />
<strong>Marine</strong> mammal and sea turtle occurrence data were accumulated from every available source; however,<br />
it was impossible to obtain every data source in existence <strong>for</strong> <strong>the</strong> <strong>Marianas</strong> MRA study area. An overview<br />
of all existing marine mammal and sea turtle data sources is found in Appendix A-3. Available marine<br />
mammal and sea turtle data displayed on <strong>the</strong> maps included in this MRA are listed in Table A-1. The data<br />
described in Table A-1 include occurrence data from marine surveys, opportunistic sighting programs,<br />
and stranding records. Miscellaneous sighting and stranding data available from <strong>the</strong> scientific literature<br />
were also used in this MRA. These literature-based records represented <strong>the</strong> vast majority of occurrence<br />
data that were available <strong>for</strong> marine mammals. Not included in Table A-1 are occurrence data from<br />
incidental fisheries bycatch records, release and recapture programs, and nesting surveys, as <strong>the</strong>se<br />
types of data ei<strong>the</strong>r were not available <strong>for</strong> inclusion at this time or did not possess <strong>the</strong> necessary detail<br />
required <strong>for</strong> inclusion in <strong>the</strong> GIS. The combined source data mentioned above were vital to <strong>the</strong> creation of<br />
occurrence polygons <strong>for</strong> protected species potentially occurring in <strong>the</strong> <strong>Marianas</strong> MRA study area.<br />
When working with <strong>the</strong> marine mammal and sea turtle data, several assumptions were made. First, it was<br />
assumed that <strong>the</strong> species identifications given were correct. This assumption was necessary since <strong>the</strong><br />
reliability of species identifications from one dataset to <strong>the</strong> next was not always known. For <strong>the</strong> sake of<br />
1-13