Dulac, LA Coastal Erosion Rate
What USGS measures 27 miles southwest of Dulac, LA
Good news, and an honest one: USGS's data can't distinguish this stretch, 27 miles southwest of Dulac, LA, from a flat trend. Whatever small movement it measured here is statistical noise, not a reliable direction, so none is claimed.
What this reading actually covers
USGS surveys the coast in transects spaced a few hundred feet apart; this page groups the nearest ones into a single ~3.5-mile reading for the stretch closest to Dulac, LA, rather than showing one arbitrary line. Segment center: 29.07, -90.93. Survey years: 2001, method LRR, from USGS's Gulf of Mexico shoreline-change assessment. That's how current the data is here, real, but not a live feed, since a shoreline survey is a major undertaking, not an annual check-in.
What backs this reading up
This reading comes from 36 individual transects averaged together, 100% of which measured erosion rather than growth. Uncertainty on this specific number: 8.05 ft/yr either side. The unadjusted figure here, -6.95 ft/yr, would place it 36 of 1211 if ranked directly - but an unreliable rank isn't a useful one, which is exactly why "no significant trend" is the headline instead. Source: USGS Open-File Report 2004-1089. Wildwood Crest, NJ sits at national rank 1185 for growth (3.33 ft/yr), one reference point among the 1211 scored segments, 1145 miles from here. 0.7 miles away, Dulac, LA is the nearest other measured stretch: also no significant trend.
Not this whole stretch, just Dulac itself: the Coastal Change Hazards Portal is USGS's own live version of this data.