Data Czar Deliberations
This chart shows total nests on Hunting Island every year since 1982 vs the total nests those same years on the SC Index Beaches (see last weeks blog). This covers 40 years of turtle data.
Only missing one year of data (1989) for Hunting Island (HI) - a hurricane destroyed the paper records that year. If someone out there knows where to find it, let us know.
On the chart, the scale on the left (blue bars) is for the Index Beaches (IB), and the scale on the right (red line) is for HI given that the IB's many more nests (20+ times) than HI.
HI shows a little different trend than the Index Beaches (IB). One might conclude that # of nests on HI actually declined in the early 1990's, though they hit some almost all-time lows ins the mid 1980's. The IB's don't show this same trend - perhaps the IB's already went through a decline earlier than HI that the data doesn't show.
Both set of beaches seems to hit lows in the late 1990's/early 2000's and then start an amazing rebound and recovery. It takes a while for turtle nests to recover from a reduction in the overall population due things like shrimping without TED's, harvesting of eggs by humans, light and chemical pollution, and a reduction in nesting grounds. It takes 20-30 years for a female hatchling, after they first leave the beach, before she returns to the beach to lay her own nest. The increase in nesting we see in the 2010's is coming from female turtles that were probably born in the mid 1980's, around the time the TED's (turtle excluder devices) were introduced on shrimpers. The mid-1970's to early 1980's were also the time that State and Federal governments started a proactive effort to address sea turtle conservation - hence the start of data collection in 1982 in SC. Google "Sally Murphy sea turtles" and read about her time as the first SC sea turtle coordinator. I have read the early HI sea turtle program reports - they report finding dead sea turtle carcasses on the beach.
Once again I think the data supports the conclusion that conversation can work without hurting the economy or people. The shrimpers pushed back against TED's at first, but got on board quickly and they actually helped design the TED's that were eventually commercialize - proverbial win win.