Cape Hatteras National Seashore Rangers Counted 104 Sea Turtle Nests in 2009
While the number of sea turtle nests observed on Cape Hatteras National Seashore in 2009 slightly declined from 2008, the 104 verified nests were far above the 43 counted just five years ago. Those 2009 nests also produced roughly 5,000 turtle hatchlings, according to the seashore's annual sea turtle report.
The 104 nests counted also represented nearly 17 percent of the 619 sea turtle nests counted throughout North Carolina, park officials said in their annual report (attached below) on sea turtles. That percentage, the highest the seashore has accounted for in the last decade, could fluctuate, though, as the statewide sea turtle tally is preliminary.
The report's details are interesting, both from a biological viewpoint as they track the successes and failures of nesting of sea turtles that come ashore at Cape Hatteras, and in light of recent controversy over off-road vehicle access to the national seashore. Legal action brought in 2007 by conservation groups concerned that ORV access on the seashore was endangering both nesting sea turtles and shorebirds protected by the Endangered Species Act led in 2008 to a consent decree that mandated beach restrictions, and even full closure, during certain times of the nesting seasons.
Against that legal backdrop, the 2009 nesting season's 104 observed nests reflects just a slight drop from the 112 counted in 2008 and marked only the second time during the 2000s that more than 100 nests had been counted. Of those 104 nests, 101 were laid by loggerhead turtles, two were green turtle nests, and just one was laid by a leatherback turtle, according to the park's accounting. Just more than half, 53, of the nests were spotted in the seashore's Hatteras District, 32 were found in the Ocracoke District, and 19 in the Bodie District.
During 2009 another 101 "false crawls" -- instances in which sea turtles failed to nest -- were observed, the report notes.
Those 104 spotted nests had, on average, 115 eggs, or 11,121 total eggs, and 3,430 hatchlings emerged on their own without human assistance, the report notes. Another 1,614 live hatchlings were discovered during nest excavations prior to storm events by park personnel and released into the Atlantic Ocean. Overall, park officials say 45.4 percent of the 11,121 eggs produced hatchlings.
And yet, storms during the nesting season greatly impacted hatchling success, the seashore staff added.
Although Hurricane Bill and Tropical Storm Danny did not greatly affect the human residents of the Outer Banks, the fact that the storms arrived so early in the hatching season meant that a large number of nests that were nearly ready to hatch got overwashed. As sea turtle eggs move into the later stages of development, they have less chance of withstanding inundation. Since so many nests were due to hatch around the time of the storms, they were unable to survive the impacts of storm overwash. Therefore, although neither storm was considered a major event, the timing of the storms resulted in a high mortality of nests at CAHA, which led to a low emergence success.
Predation -- by feral cats and crabs -- also were recorded throughout the nesting season, although seashore officials couldn't put a number on hatchlings lost to this. Also unknown was whether sea turtles were deterred from nesting by human activities, the report noted. "Many visitors at CAHA, especially in front of the villages, left their recreational beach equipment and chairs or loungers on the beach overnight. This equipment and furniture can cause turtles to forgo laying eggs by hampering or trapping animals attempting to locate a nesting site," the report said.
There were more than a few instances recorded of seashore visitors in one way or another interfering with or interrupting nesting turtles or their emerging hatchlings.
CH17: This false crawl occurred on Lighthouse Beach on the night of July 3. The tracks were documented as coming right up to a still warm fire pit, at which point the animal turned around and went back into the water.
CO34: This false crawl was found on the morning of July 15 near a walkover on Ocracoke Island. It was evident that the nesting turtle had dug an egg chamber and then abandoned the site. The following day a visitor contacted CAHA to ask about the turtle, and informed biologists that there had been several families watching with cameras and flashlights.
NH06: This nest in Hatteras Village was expanded and within the hatch window when a wind storm on the night of August 3 blew a beach canopy directly onto the nest site. The canopy was removed by morning turtle patrol and tagged. No hatchlings emerged from this nest on that night and there was no observed damage.
NH12: This nest was located just north of Hatteras Village in Isabel Inlet. On the night of August 10, approximately 25 hatchlings came out of the filter fencing and headed south toward Hatteras Village. It is unknown how many hatchlings made it to the water. Cat tracks were found near the nest on the same night.
NH16: This nest was laid in the early morning hours of June 27 just north of Ramp 44 inside the pedestrian corridor that was in place at the time. When turtle patrol came out of Ramp 43 that morning at 5:30 a.m., a vehicle was already south of the ramp with its headlights on (vehicles are restricted by the consent decree regulations until 6 a.m.). Turtle patrol asked the vehicle to leave the beach until the allotted time, and then entered the pedestrian corridor. A nesting loggerhead was just finishing a very low nest about 30 yards from where the vehicle was parked. The nest was moved to higher ground.
NH46: This nest was located between Ramp 43 and Ramp 44 on Hatteras Island. On the night of Oct 11, approximately 30 hatchlings came out of the protected filter fencing area and headed south from their nest toward Cape Point. They exited the closure at the south end and then moved toward the water. About five of the hatchlings went into a tire track, and either made it to the water or were predated.
NBH05: This nest was laid on the night of June 16 in the tri-village area. That night, CAHA staff received a call from Dare County Central reporting that pedestrians on the beach were harassing a nesting turtle. The following morning the nest was found, but was so low on the beach that it had already been mildly washed over. The nest was relocated to higher ground. Since the nest had a good success, it is unlikely that any damage was sustained.
NBH12: This nest was laid on the night of June 28th in the tri-village area. This nest was not found by morning turtle patrol due to the amount of pedestrian tracks obscuring the crawl. One of the pedestrians who had been out the night before contacted CAHA to report that there was a nest that had not been marked. The visitor informed CAHA that that the animal had been surrounded by more than 20 people. The visitor indicated where the nest was located and staff was able to confirm eggs and install a closure. The nest was not relocated.
NO30: This green nest was located between Ramp 70 and Ramp 72 on Ocracoke Island. After Ramp 72 closed due to flooding, there were several times when vehicles attempted to drive below the full beach closure to reach South Point. On the night that some of the hatchlings emerged, at least two vehicles went below the closure in the surf line. It is unknown whether any of the emerging hatchlings were impacted.
There also were quite a few instances where seashore visitors ignored closures established around turtle nests.
In 2009, there were numerous violations of turtle closures, some more serious than others. Although closure signs were highly visible and could be read easily, law enforcement and resource management staff documented violations at turtle closures throughout the nesting and hatching seasons. Entry into a turtle nesting area would require people to pass under, drive through flagged string tied between signed posts, or pass below signs by the tide line. Signs were posted as low on the beach as possible. Because of extremely high sign loss near the shoreline at all expanded turtle nests, the closure signs closest to the water were replaced with carsonite, which holds better in the moist sand. Although carsonite is extremely costly, staff roped them together so that if the tide washed them out, there was a better chance of recovering them.
Few of the violations involved off-road vehicles, the seashore pointed out.
ORV violations of turtle closures were relatively rare. There were several accounts of vehicles driving below (i.e. ocean-side of) the expanded turtle closures in the morning before any washed out signs in the intertidal zone could be replaced. It is unknown how many hatchlings, if any, were affected by these actions, either by being run over or by being stuck in tire tracks. There were no observed losses to this type of violation, although it is known that hatchlings were emerging from NO30 (a green nest) during the same night that some of these violations took place (see above)
That said, there were at least two notable exceptions to that observation:
NBH10: On the morning of July 26th, staff on turtle patrol for the Bodie Hatteras District noticed that a nest closure was “missing” in the tri-village area. After going back through the area, she found that someone had removed the four signs, string, flagging, and PVC poles that were surrounding the nest site. Two of the signs were later found 0.2 miles down the beach. One sign was found behind the primary dune line with the PVC poles and the fourth sign was never recovered. Many sets of pedestrian footprints were found over the nest site. The eggs were checked and the closure re-installed at the expanded size. As the nest had a good success, it is unlikely that this incident resulted in any harm to the nest itself.
NH33: On the morning of September 2, staff on the turtle patrol for the Hatteras South run noticed that string was down at the NH33 nest site, which was an expanded closure just north of Ramp 49. It was found that a vehicle had driven though the sting at one end of the closure, run through the filter fencing, and then exited the closure by driving through the string at the other end. It is unknown whether the vehicle was also in violation of the CD nighttime driving restriction. The filter fencing was repaired and the closure expanded. There was no observed damage to the actual nest.
Also monitored by seashore officials were the number of sea turtle "strandings," events in which non-nesting sea turtles come ashore either because they're injured, sick, or dead and washed ashore. During 2009 there were 297 strandings noted.
Of the total strandings, 242 (81%) turtles were dead when found. Of the 55 live strandings (19%), all were transferred to the North Carolina Aquarium on Roanoke Island for rehabilitation, except for one live stranding that was released. Most of these live strandings were a result of ‘cold stunning’ where water temperatures become too cold for sea turtles to function normally. Often, these turtles had pre-existing conditions that made them more susceptible to a cold stun event. Examples of pre-existing conditions include old boat strike wounds, plastic (e.g. wrappers, toys) in the gastrointestinal tract, etc.
Necropsies were preformed on 191 of the 241 dead strandings (79%). Additionally, some strandings have been frozen and saved for later necropsy training sessions. Cause of death in most cases was unknown; however eight strandings had obvious signs of human interaction (prop wounds, hooks, or plastic). Additionally, seven turtles had signs of fisheries interactions from entanglement or drowning (as determined by NCWRC biologists-often evidenced by remaining gear or obvious entanglement lesions around the neck or flippers). Cold temperatures attributed to 137 strandings (50 live and 87 dead).