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Fishery Bulletin 1 10(4) 
Map showing the location and spatial extent of the regional sea turtle trawl survey conducted 
in 2000-03, 2008-09, and 2011 between Winyah Bay, South Carolina, (33.1°N) and St. Augus- 
tine, Florida, (29.9°N), and the 20-m and 200-m depth contours. Thick black bars denote breaks 
between geographic subregions within the study area. 
FL) and internally (passive integrated transponder tag 
TX1406L, 125 kHz, Biomark, Inc., Boise, ID) before 
release to assess recapture events. 
Data analysis 
Moran’s index (ArcGIS Arclnfo Desktop, vers. 10.0; 
ESRI, Redlands, CA) was used to evaluate the spatial 
randomness of trawling events among years. Moran’s 
index measures event similarity based on both the loca- 
tions (x, y coordinates) and attribute values (year). 
With any set of event locations, and a single attribute, 
this index measures whether the location pattern is 
clustered, dispersed, or random on the basis of that 
attribute. The Moran’s index value runs from +1.0 (clus- 
tering) to -1.0 (dispersion), and large or small (negative) 
Z scores indicate Moran’s index values in the tails of the 
distribution and unlikely to be random. 
A chi-square contingency test (significance level 
[ of] = 0.05) was performed in Minitab 15 (Minitab, Inc., 
State College, PA) to evaluate annual distribution among 
3 types of seafloor habitat — “hard,” “probably hard,” 
and “not hard” — as determined from the co-occurrence 
of >3, 2, or <1 of 56 hard-bottom indicator species 2 ' 3 , 
respectively. Temporal trends in distribution of seafloor 
types were analyzed with linear regression. Sampling 
effort among years and subregions was also examined 
with chi-square analysis. 
Loggerhead sea turtle catch per event (response vari- 
able) was examined with R software (vers. 2.13.0; R De- 
velopment Core Team, 2011) in the context of an offset 
term (log of the linear distance, in kilometers, between 
trawl start and end locations). Catch, rather than catch 
rate, was analyzed given a 33% decrease in permit- 
ted bottom trawl time (and, therefore, trawl transect 
length) during 2008-09 relative to the other five survey 
2 Reed, J. K. 2004. General description of deep-water coral 
reefs of Florida, Georgia and South Carolina: A summary of 
current knowledge of the distribution, habitat, and associated 
fauna. A Report to the South Atlantic Fishery Management 
Council, NOAA, NMFS, 71 p 
3 VanDolah, R., P. Maier, G. Sedberry, C. Barans, F. Idris, and 
V. Henry. 1994. Distribution of bottom shelf habitats on 
the continental shelf off South Carolina and Georgia. Final 
Report submitted to Southeast Area Monitoring and Assess- 
ment Program South Atlantic Committee, 46 p. 
