Cape Hatteras

National Seashore
North Carolina

U.S. Department of the Interior
National Park Service

    Cape Hatteras National Seashore (CAHA) beaches were patrolled daily between June 1 and August 27 in search of turtle crawls. Park volunteers, Student Conservation Association volunteers and Park staff conducted patrols. Approximately 55 miles were monitored each day within the areas south of Nags Head on Bodie Island, and all of Hatteras and Ocracoke Islands (excluding Pea Island Wildlife Refuge).

Nest Composition and Distribution

    Ninety-two confirmed nests were located in 1999. Sixty-three nests (69%) were found on Hatteras Island, twenty-eight (30%) of the nests were located on Ocracoke Island and one nest (1%) was found on Bodie Island. Hatteras Island had 14 less recorded nests than last season, while Ocracoke Island had ten more nests. The first known nest of the season was laid in mid-May and the last nest was found on August 27. This season was the third highest season on record since extensive monitoring began in 1987.

    Only one species of sea turtle was known to have nested on CAHA beaches in 1999; all nests were laid by loggerhead turtles, Caretta caretta. One nest and a few crawls were believed to be from green turtles, but could not be confirmed.

    All documented nests were found by patrols and recorded the morning after the nest was laid. In two instances, however, visitors informing park staff of turtle activity reported nests. On one occasion, visitors reported seeing approximately 100 turtle hatchlings emerge from the sand and crawl to the ocean near Frisco Pier. According to the hatch date of July 11, this nest was laid in mid-May, prior to daily patrolling for nests. The hatch success rate or number of hatchlings was not determined, but this site was included in the data as a numbered nest site, with the hatching information unknown. In a second incidence, visitors reported seeing a turtle crawl up on the Avon area beach and lay eggs, but after investigation, the exact site could not be determined. To the best estimations, the area was marked with signs and treated as a nest area, although this nest could not be confirmed and is not included in the following data.

Treatment

    Beaches used for most nest relocations were: 1) south of Ramp 59 in Ocracoke; 2) between ramps 55A and 57 near Hatteras Inlet; 3) Canadian Hole ocean beach; 4) south of Ramp 30 on Hatteras Island. Several nests, however, were relocated in areas other than the above locations closer to the original nest sites.

    In previous seasons, any crawl found with two body pits and other characteristics of a nest site, but yielding no eggs to the observer, was assumed to be and categorized as a false crawl. This season, any crawl appearing to be "textbook" nest to the observer, was categorized as a "dig" if no eggs were found. Rather than abandoning the site because staff could not locate eggs (recognizing the possibility of human error), these sites were treated exactly like nest sites, with all information recorded, poles labeled, and transponders inserted underground. In all cases up to Hurricane Dennis, dig sites revealed themselves to be true nests after depressions formed and hatchlings emerged. It should be noted that the dig sites which yielded nests are included in the nest numbers and calculations, and the digs which were lost to storms were kept in the dig category and not included in overall nest numbers or calculations.

    Thirty-seven nests (40%) were protected at the original site where found. Decisions to relocate fifty-five nests (60%) were based on several parameters such as erosion, close proximity to high tide line, or escarped dune face, which threatens the nest with sand deposition. More specifically, thirty-six nests (57%) were relocated on Hatteras Island, eighteen (64%) on Ocracoke Island, and one (100%) on Bodie Island. Aside from natural threats to turtle nests, other reasons to relocate were due to human activity, and include such disturbances created by off-road vehicles (ORV), recreational day use, and artificial lighting from villages and fishing piers. The Park tried to leave nests in place, even within ORV areas, if the site appeared to be suitable habitat. However, there were occasions on which the staff relocated turtle nests due primarily to high ORV use, especially if the vehicles could not pass in back of the nest area. In 1998, a nest enclosure within a high traffic area completely blocked traffic during the hatching period. This closure was often ignored and vehicles intentionally drove through the area, missing the nest site by a few feet. This season, staff relocated two nests from their original locations in the dunes further towards the tideline in order to make an ORV lane for vehicles - a practice that should not continue.

    Of the 55 relocated nests, thirty-one nests (57%) were moved because of natural factors, fifteen (27%) due to potential human disturbance, and nine (16%) because both human and natural factors threatened the nest. The most common natural factors threatening turtle nest areas are that the nest sites are laid either too close to the tideline or are on a narrow beach. More beaches in the Seashore are becoming narrow since the artificial dune line prevents natural overwash which would create additional beach habitat. A common human factor causing relocation occurs when nests are located within a mile of a fishing pier. Piers emit light pollution attracting hatchlings which fall prey to fish which congregate near piers. The resource management division has submitted recommendations to the superintendent that would decrease light pollution generated by the three fishing piers. The piers are concessions in the park and operate under permits. In specific situations, high ORV traffic can be the decisive factor in relocating nests especially when there is little space to safely reroute vehicles behind the site.

Hatching Success

    All nests that successfully hatched prior to Hurricane Dennis in late August were examined to determine productivity rates. Nests were excavated at a minimum of 72 hours after hatching events. In cases where hatch dates were unknown, nests would be unearthed 80-90 days after the laying date. A total of only 3204 known eggs hatched. Of these, 2990 hatchlings emerged from the nest cavities. These totals are low, primarily due to hurricane activity (see Factors Influencing Nest Success). The season's overall hatching success at CAHA in 1999 was 30% (Table 3). Thirty-nine nests hatching prior to the hurricane season averaged a 63% hatch rate. Only one nest was known to produce hatchlings following the hurricanes. Individual nest success ranged from 0% to 99%.

    Overall in CAHA, relocated nests had a 39% hatch success while non-relocated nests had a 30% hatch success rate. More specifically, Hatteras Island had a 46% hatch rate for relocated nests, and 29% for non-relocated nests. Ocracoke had an 8% hatch rate for relocated nests and 31% for nests in their original location. Finally, Bodie Island relocated its only nest, and its' success rate was 56%. It is vital to state that the low percentages are not directly related to the relocation of nests, and these percentages are not to suggest that relocating nests increases hatching success. These percentages are a reflection of storm activity because many nests yielded a hatch rate of 0% and were averaged in with the hatched nests. The location of nests and where the beaches were eroded or covered with more sand also was a factor in these hatch rates.

Nest Protection

    Designated relocation areas, containing several nests each were posted along their perimeters. Any single nest left in place or moved to a site other than one of the established relocation areas was protected by an approximately 30'x 30' posted closure during the incubation period. Fifty days into incubation, these small closures were expanded to the surf line and to a width of 200'-300' parallel to shoreline. Opposite to the surfline on the upper end of the enclosure, the closed area was expanded to a minimum of 50' duneward from the nest. If present, all vehicle tracks were smoothed over manually with rakes or with a steel mat attached to an ATV, so as not to impede hatchlings attempting to reach the surf. In several cases silt fence was used behind nests nearing hatching dates. Fencing was used to block light pollution, as an added safeguard in ORV areas or, on Ocracoke Island, to protect hatchlings emerging close to Highway 12. Also in 1999, several new and larger signs were used to better mark closures. These notified drivers that the area included a closure of the surf line at all tides. Interpretive signs warned how vehicle traffic could harm eggs and hatchlings. Traffic detours behind the nest area were more clearly signed this season as well. Signs were removed no earlier than 72 hours after hatching occurred, and after the excavation of the nest was completed.

    Several nests left in their original locations were concurrently in high visitor use areas. Cape Point to Ramp 49 by Frisco Campground was a very high ORV area. Thirteen nest sites were between these two points. In all cases, since this area is fairly wide, ORV's were detoured behind the nest. Relocation of a few nests was required in order to provide vehicle lanes. Vehicle tracks were repeatedly found passing through closures near low tide, despite efforts by the staff to maintain surfline closure and reposition signs. Once ORV tracks became well established along the detour route, compliance was higher. Pedestrians often walked through the closures along the ocean's edge but footprints were seldom seen above the tide line.

    The relocation area located near mile 32 on Hatteras Island was completely closed to traffic during the hatching period. This included approximately one mile of beach. Hence, all vehicles heading southward from Ramp 30 or northward from Ramp 34 could not pass to the next ramp on the beach. Large signs indicating this were posted to alert drivers of the inability to pass through the enclosure. In general, this is not a heavy traffic area compared to other stretches of Park beach. Overall, there was high compliance with the closure, although low tide breakthroughs existed sporadically. Highly eroded beaches north and south of the enclosed area diminished the overall number of vehicles using this general area. This likely contributed to the relatively high ORV compliance in this relocation site. It should also be noted that with an increased maintenance of signs and string, there is a higher compliance with enclosures.

    Commercial fishermen operating within the Seashore were notified that fishing activities were not allowed in any of these posted areas.

False Crawls

    A total of sixty-nine false crawls were found during the 1999 breeding season. Of these, thirty-nine (57%) were found in areas open to ORV use. Eight false crawls (12%) were located in heavy day use areas that included lifeguard beaches and parking lots with a walkover area. Two false crawls (3%) were on beaches adjacent to village development, and three (4%) were located in areas within one mile of a pier. It should be noted that the pier areas are also in the vicinity of village beaches, in Rodanthe, Avon, and Frisco, but were included in the pier data group. The remaining seventeen (24%) were found on beaches with lower concentrations of human activity. The highest percentage of false crawls (60%) occurred on Hatteras Island.

Factors Influencing Nest Success

    Hurricane related events were the definitive cause of unsuccessful nest hatches this season. Hurricane Dennis, in particular, became stationary just off of the Outer Banks for several days. Overwash and flooding were severe, and detrimental to nest areas due to saltwater intrusion and extreme conditions of temperature and salinity in which nests cannot survive. Even worse were sand deposition and erosion. On the south facing beaches of Hatteras Island, most of the nest sites did still exist after the storm, but were covered with as much as five feet of sand. Many nests on Ocracoke Island were entirely swept away. On the east facing beaches of Hatteras Island and Bodie Island, many nests were lost to erosion and not present at all after the storm.

    Following Dennis, were Hurricanes Floyd, Gert, and Irene, which all brought ocean-swells, extreme high tides and rough surf. Altogether on CAHA, twenty-seven nests and six digs were lost to the hurricanes, meaning that the nest sites were washed away and could not be located after the storm. On Hatteras Island, 20 nests and five digs were lost, and on Ocracoke Island, seven nests and one dig were lost. These nests were all given a 0% hatch success rate. Also given a 0% hatch rate were the nests which were located and excavated, but yielding all unhatched eggs, ranging from virtually undeveloped to very developed embryos. In addition, four to five feet of sand deposition due to storms covered eight nests. Eggs could not be located during excavations. These nests were consequently categorized as "unknown," with unknown hatch success rates, even though they likely had no hatching success at all.

    The loss of 26 nests and 6 digs occurred during the weeklong period when Hurricane Dennis impacted the North Carolina coast. An additional nest was known to be lost from high seas generated by Hurricane Floyd. It is unclear, however, if the rest of the unknown and entirely unhatched nests were primarily impacted by Hurricane Dennis or from a combination of impacts created by the additional storms. The success rates before Hurricane Dennis were significantly higher compared to the success rates after the storm, which was virtually nil, and the low success rates for the season were primarily due to the disruption of hatches by the storms. In June, localized ocean flooding on Ocracoke was likely responsible for low hatch success of four early season nests.

    Aside from storm activity, ghost crab burrows were observed near some nest cavities but could not be attributed to any poor nest success. Hatteras Island had six documented cases of ghost crab presence in or on top of nest areas. On a few occasions, eggshells were found outside ghost crab holes. The Park has no information on the local impacts of ghost crab predation. In one instance on Bodie Island, a fox was observed to be unearthing a nest, and burying dead hatchlings. There was an attempt by a biological technician to rebury the nest, but the hatchlings proceeded to emerge and crawl to the ocean. Unhatched eggs remained reburied, but later the same day, the fox returned and ate the remaining eggs. Ghost crabs were also found in this nest.

Human Disturbance

    On three occasions, turtle nest sites were intentionally disturbed. On Hatteras Island, near Ramp 45, a biological technician found four holes dug in a consecutive line with the nest markers in an apparent but failed attempt to locate turtle eggs. On Ocracoke Island, humans disturbed the sands covering two individual nests. No damage to the eggs or hatchlings was found. All sites were clearly marked with signs. In two separate occasions, strategically placed poles used to help staff locate nest cavities were removed and left scattered on the beach.

    Most pedestrians respected the posted areas. Eight incidents of human tracks were recorded. In addition to these reports, moderate foot traffic was found in the Canadian Hole relocation areas. One visitor found within this area believed the closure signs were for vehicles only. On Ocracoke, human tracks were found on top of a nest that had hatched the previous night.

    As visitation has increased so has night activity that can interfere with nesting females and emerging hatchlings. Beach campfires are more frequently seen, especially near the villages, day use areas, campgrounds and ORV ramps. Fireworks are sold locally and are commonly used, although illegal, on CAHA beaches. ORVs are permitted to operate on CAHA beaches after dark. Also reflecting increased tourism are increased reports of turtle sightings at night; occasionally visitors will call to report turtles who are nesting or crawling on the beach, as well as reports of hatching nests.

    As in previously discussed cases, many but not all beach drivers respected marked turtle areas (See Nest Protection). In total, twenty-one sets of vehicle tracks were noted within closures, often along the tide line. This is likely a conservative number since observers were not present at all sites at all times. Additionally, evidence of tire tracks washed away with each high tide. ORVs drove through areas where signs clearly marked established detours behind the closures. Most ORVs drove in front of the nest areas during periods of low tide. Signs could not be placed in the low tide area, since they would wash away with the approach of each high tide and accompanying waves. Signs placed at the high water mark did state the surf line was closed at all tides. There were at least five documented incidents of vehicles breaking through the posted areas well above the high tide line. There were nine cases reported of property damage to signs, posts and twine.

    Two crawls were so obscured by ORV tracks that staff could not deduce where the body pits and potential nest cavities were located. Either the ORVs were driving at night or early morning, before the patrol was able to reach the site. Nests are likely missed each year hidden by vehicle tracks or in some cases heavy pedestrian tracks. On another occasion, footprints and dog tracks covered an existing depressed area, so that it was difficult to tell if hatching occurred. It should be noted that this was in the Canadian Hole relocation area and this site was only posted by signs, and was not protected with string and flagging.

    A pet leash law, carrying a $100 fine, exists at CAHA. The regulation is not consistently enforced in all areas of the Park. Most dogs on the beach are not leased or only leashed by their owners as a Park vehicle approaches. Dogs can be a serious threat by digging up incubating eggs. On two occasions, dogs were seen within marked turtle nest sites. Tracks were reported on at least three other occasions.

    Artificial lights appeared to have misdirected some hatchlings in the area south of Cape Point in the vicinity of Ramp 45 and the interdunal roads leading to the beach. At nest #10, the hatchlings crawled towards the dunes, turned parallel to the ocean, and then crawled to the ocean. Hatchlings from nest #20 also gravitated towards the same direction. Nest #21 showed the worst of the hatchling misorientation. A few of the hatchlings did find the ocean, others crawled parallel to the ocean into bird enclosures, other closed turtle areas, and even the nearby ramp. Four hatchlings were found in tire tracks and were redirected by staff. Hatchling tracks were found over 300 feet away from original nest area. It should be noted that Frisco pier is about 4 miles away from this location but is in clear view because of the curve of the island. Light pollution from Frisco and Hatteras villages could also be the cause of such misorientation by hatchlings. Consequently, filter fences were erected around the nest sites in nearby locations in order to prevent such misdirection.

Highway 12

    Highway 12 presented a unique problem in 1999. Prior to the nesting season, storms had flattened a few miles of dunes at the northern end of Ocracoke Island. This exposed the beach to the nearby highway. It was feared nesting turtles could end up on the highway and be struck by passing cars. US Fish and Wildlife Service and CAHA spent over four thousand dollars to purchase posts and fencing materials. Park staff and volunteers erected the fencing as a barricade. Fencing also had to be erected in an 800-foot section north of Buxton after a female loggerhead turtle crossed the narrow beach and was found disoriented on the nearby highway. She was rescued and returned to the ocean unharmed.

    In 1999, a record number of 226 stranded sea turtles were documented along shores of CAHA. This is a dramatic increase compared to past years. Annual totals between 1996 and 1998 fell between 47 and 98 turtles. Strandings have risen on ocean beaches as well as inshore (soundside) waters. This season, 138 turtles were recovered from the ocean beach and 88 on the soundside of the islands. Hatteras and Ocracoke Islands reported the highest numbers. Park wide, 149 (66%) were identified as loggerhead, 22 (10%) were green and 55 (24%) were Kemp's ridley.

    Thirteen turtles (6%) were alive when discovered. They were transported to Roanoke Island Animal Hospital. Veterinarians made health assessments and if possible the animals were later transported to holding tanks at the NC Aquarium in Manteo. Network for Endangered Sea Turtles (NEST), a volunteer group based in the Nags Head, North Carolina area, cared for them until released. The majority of these live turtles were victims of hypothermia when sound water temperatures suddenly plummeted in response to late season cold fronts. Once recuperated, these animals were released in warm waters of the Gulf Stream. The US Coast Guard, Hatteras Inlet Station released many of these turtles.