Sea tur­tle hatch­ing and nest num­bers de­crease again in SC

The Charlotte Observer (Sunday) - - Stay Connected - BY BRI­ANA SAUN­DERS bsaun­[email protected]­land­packet.com

South Carolina’s sea tur­tle hatch­ing num­bers were lower for the sec­ond year in a row, but that’s no rea­son to panic, tur­tle ex­perts say.

Pre­lim­i­nary num­bers, ac­cord­ing to the South Carolina De­part­ment of nat­u­ral re­sources’ sea tur­tle nest mon­i­tor­ing sys­tem, show:

173,839 hatched eggs

were re­ported in 2018.

324,595 hatched eggs

were re­ported in 2017.

418,564 hatched eggs

were re­ported in 2016.

The num­ber of nests also de­creased dras­ti­cally over the years:

2,763 nests were re

ported in 2018.

5,250 nests were re

ported in 2017.

6,446 nests were re

ported in 2016.

Both 2016 and 2018 saw preda­tory an­i­mals as the main rea­son for sig­nif­i­cant nest losses.

In 2016 rac­coons were listed as the main cause.

Then, in 2018, coy­ote depre­da­tion was listed as the main cause, though South Carolina wildlife of­fi­cials said coy­otes aren’t con­sid­ered a ma­jor prob­lem at this time.

In 2017, tides and storms were the rea­son most of­ten cited for sig­nif­i­cant nest losses, ac­cord­ing to the mon­i­tor­ing sys­tem.

WHY THE DE­CREASE?

The tur­tles’ mat­ing cy­cle is cycli­cal, so a de­crease is not a cause for alarm, ex­plained Michelle Pate, SCDNR’s Sea Tur­tle Ma­rine Preser­va­tion Pro­gram co­or­di­na­tor.

She said sea tur­tles nest ev­ery two-three years, not ev­ery year.

“Nest and egg losses fluc­tu­ate from year to year de­pend­ing on the num­ber of storms af­fect­ing the coast­line, num­ber of preda­tors liv­ing on a beach, preda­tor re­moval that oc­curs on a beach, num­ber of nests avail­able to be af­fected and more,” she wrote in a state­ment about the sea­son.

SCDNR data show how the num­ber of nests fluc­tu­ates by year, so a de­crease from 2017 into 2018 was ex­pected.

IM­PACT OF STORMS

The tim­ing of Trop­i­cal Storm Irma in 2017 is key when com­par­ing it with the im­pact of Hur­ri­cane Florence and Trop­i­cal Storm Michael in 2018, said Erin Weeks, a spokesper­son for SCDNR.

Also, Hur­ri­cane Flo- rence’s im­pact on South Carolina mostly was in the north­ern part of the state, where the sea tur­tle pop­u­la­tion is low, she said.

Am­ber Kuehn, a ma­rine bi­ol­o­gist who man­ages the Sea Tur­tle Pa­trol Hil­ton Head, noted sev­eral other fac­tors that might have played a role in the de­crease.

Sim­i­lar to when 2014 had a harsh win­ter, this year also saw wa­ter tem­per­a­tures re­main at 38 de­grees for an ex­tended pe­riod, she said.

This af­fects sea tur­tles’ ma­jor food source – crabs, Kuehn said. Fe­male sea tur­tles need to feed in or­der to have en­ergy to mate and lay their eggs.

There also was an is­sue with a lot of “rain bombs” – huge mi­crobursts of pre­cip­i­ta­tion in a small area – af­fect­ing the coast, said Kuehn.

This caused tidal in­un­da­tion where a lot of nests flooded be­cause of the ground not ab­sorb­ing the amount of wa­ter hit­ting land.

NEXT YEAR’S OUT­LOOK

Sea Tur­tle Pa­trol Hil­ton Head plans to be less con­ser­va­tive in re­lo­cat­ing its tur­tle nests next year, Kuehn said.

“One of the things that we can do (to help sea tur­tles) is to make their jour­ney to the wa­ter safe,” she said.

Af­ter that, it’s up to Mother Na­ture and the sea tur­tle hatch­lings if they sur­vive into adult­hood.

Time will tell on how 2019 num­bers will stack up, but ex­perts re­main hope­ful based on pre­vi­ous trends.

BRAD ROCCO

A sea tur­tle hatch­ling heads for the ocean on Hil­ton Head Is­land. South Carolina’s sea tur­tle nest mon­i­tor­ing sys­tem tracks the num­ber of nests and hatched eggs each year.

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