Hongdo Island Research Articles

ANALYSIS ON FAILURE CAUSES OF DOCK DUE TO ABNORMAL WIND WAVES

In a coastal area where the water depth changes rapidly, waves developed in the offshore propagate to the coast, with a massive energy without any dissipation. Particular attention should be paid to the occurrence of damage in an island, where the land is open towards the ocean, in the event of abnormal wind wave, and design of structures in such region requires thorough examination. The southern and northern coasts of Hongdo Island located in the western coast of South Korea face the ocean side, and are directly affected when a typhoon or a high wave occurs. Therefore, structural damage due to wave generation frequently occurred in the coasts, and repair and reinforcement work were carried out several times.

A new record of <i>Carex foraminata</i> (Cyperaceae) in Korean flora

We report a new distribution of <i>Carex foraminata</i> C. B. Clarke on the Korean Peninsula. This species was first reported in China and is distributed in Jiangxi and Zhejiang Provinces. We found this species on Hongdo Island in Heuksan-myeon, Shinan-gun, Jeollanam- do in Korea. <i>Carex foraminata</i> is similar to the related taxa <i>C. brevispicula</i> G. H. Nam & G. Y. Chung, <i>C. chungii</i> Z. P. Wang, and <i>C. genkaiensis</i> Ohwi in that its achenes are constricted in the middle part. However, <i>C. foraminata</i> is distinguished from <i>C. brevispicula</i> and <i>C. chungii</i> by its pistillate scale apexes, which are acute or shortly awned and by its achene apexes, which are shortly cylindrical; <i>C. foraminata</i> is distinguished from <i>C. genkaiensis</i> by its pistillate scale and achene shape. A precise description, illustration, photographs, and a key to related taxa are provided.

한려해상국립공원 홍도와 태안 난도의 괭이갈매기 번식현황

Seabirds take a long time to recover if their population decreases due to slow growth and small clutch size. This study was conducted to collect basic data of breeding status of Black-tailed gulls (Larus crassirostris) on Hongdo Island of Hallyeohaesang National Park and and Nando Island. These two breeding colonies are designated as natural monuments. We investigated egg volume, clutch size and nest density in May 2022. As results, clutch size was 1.89±0.57 in Hongdo Island and 1.91±0.48 in Nando Island. The egg volume was also similar between Hongdo Island (59.22±5.47) and Nando Island (59.63±3.96). The nest density was significantly higher in Hongdo Island (1.27±0.18/㎡) than in Nando Island(0.54±0.15/㎡). Breeding population was estimated as 56,729 pairs in Hongdo Island while 14,112 pairs in Nando Island based on the proportion of breeding areas. Long-term monitoring is required to know the trends of Black-tailed gulls to protect breeding colonies.

First Report of Habitat Ranges in Black-tailed Gulls (Larus crassirostris) breeding on Hongdo Island, Hallyeohaesang National Park

바닷새의 서식 범위 파악은 개체군 변동을 이해하고 종 보호를 위해 중요하다. 본 연구는 한려해상국립공원 홍도에서 번식하는 괭이갈매기의 연중 서식 범위 파악을 위해 수행되었다. 홍도 괭이갈매기 번식지에서 2018년 괭이갈매기 4개체와 2019년 2개체에 조류위치추적기를 부착하여 위치정보를 수집하였다. 괭이갈매기는 홍도로부터 부산, 거제, 통영, 여수 등 100km 내외의 서식 범위를 이용하였다. 괭이갈매기의 서식 범위는 번식기에 비번식기보다 더 넓었다. 1년 이상 위치를 추적한 성조의 경우 번식기인 5월부터 8월까지는 홍도와 부산, 거제, 통영, 여수 등에 서식했다. 이후에는 남하하여 일본으로 이동한 후 이듬해 2월까지 머물렀다가 3월이 되자 홍도로 다시 되돌아왔다. 본 연구는 한려 해상국립공원 홍도에서 번식하는 괭이갈매기의 서식 범위를 밝힌 첫 논문이다.

Taxonomic identity of Crepidiastrum ×nakaii recorded on Hongdo Island

The plant known as “Hong-do-go-deul-ppae-gi” on Hongdo Island, belonging to the genus Crepidiastrum, has been recorded as C. ×nakaii, a hybrid between C. denticulatum and C. platyphyllum. During a survey of the flora of Hongdo Island, we reexamined the taxonomic identity of “Hong-do-go-deul-ppae-gi”. The morphological traits, geographical distribution, and internal transcribed spacer (ITS) sequences of “Hong-do-go-deul-ppae-gi” were compared to related species within the genus. A morphological examination revealed that the plant was similar to C. lanceolatum in that it has subshrub stems with caudex stout, 8 inner involucrals bracts, and 10 to 12 florets. In contrast, similarities to C. denticulatum were observed in terms of radical leaves deciduous in the flowering period, cauline leaves membranous with acute serrations, and beaked achenes. Furthermore, C. denticulatum and C. lanceolatum grew on Hongdo Island and nearby areas, but C. platyphyllum was not distributed in these areas. The results of morphological and distributional investigations revealed that the Hongdo Island plant should be regarded as C. ×muratagenii, a hybrid between C. denticulatum and C. lanceolatum, not C. ×nakaii, which is a hybrid between C. denticulatum and C. platyphyllum. However, the resolution of the ITS sequences was insufficient such that we could not separate the examined species.

Re-examination of the vascular plants on Hongdo Island, Korea

This study was carried out to survey the flora of Hongdo Island in Sinan-gun, Jeollanam-do, South Korea. Specimens collected from previous Hongdo flora studies were reexamined using a relevant biodiversity database, and field surveys were carried out 22 times from April of 2003 to October of 2020. Based on the specimens collected during both previous studies and this study, the identified vascular plants of Hongdo consisted of 472 taxa comprising 102 families, 296 genera, 425 species, 6 subspecies, and 41 varieties. Among them, 111 taxa are newly recorded in this study, and 6 taxa are described in detail in terms of their morphological characteristics and habitat. Also, 29 taxa were reviewed or re-identified with corresponding taxonomic annotations. In Korea, Hongdo represents the northern distributional limit of the 4 taxa of Goodyera biflora, Damnacanthus major, Calanthe aristulifera, and Hemerocallis hongdoensis. Moreover, Hosta yingeri and Saussurea polylepis are endemic to Hongdo and nearby islands in Korea. Distribution maps of these species were prepared. Protected species designated by the Ministry of Environment were 7 taxa consisting of 2 taxa of level I, specifically Sedirea japonica and Neofinetia falcata, and 5 taxa of level II, which were Cymbidium macrorhizon, Woodwardia japonica, Dendrobium moniliforme, Calanthe aristulifera, and Bulbophyllum inconspicuum. Red list plants as designated by the National Institute of Biological Resources numbered 11 taxa. Naturalized plants numbered 40 taxa.

A new species and a new record of <i>Meghimatium</i> Slugs (Pulmonata: Philomycidae) in Korea

Until now, five species (Meghimatium bilineatum, M. fruhstorferi, Limax flavus, L. marginatus, Deroceras reticulatum) in three genera of families Philomycidae and Limacidae have been reported in Korea. Philomycidae is a family of air-breathing land snails. Meghimatium hongdoensis sp. nov. is described based on its middle size (60-80 mm in body length), its body coloration (dark-red yellow), no dorsal with streaks, its genitalia, and 16rDNA sequence analysis. Specimens of this new species were collected from Hongdo island, Sinan-gun, Jeollanam-do, Korea. This species is only known from the type locality at Hongdo to date. It could be found in high-humidity sites. Meghimatium uniforme (Laidlaw 1937) was the first one reported in Korea. It was also collected from Gageodo island, Sinan-gun, Jeollanam-do, Korea. In this study, morphological characteristics including their radula and genital structures of these two species were described. Preliminary results of mitochondrial 16S rDNA sequencing and phylogenetic analyses indicated that these species belonged to the Korean clade.

A new distribution record of Sedum kiangnanense (Crassulaceae) in Korea

We report a new distribution of Sedum kiangnanense D. Q. Wang & Z. F. Wu on the Korean Peninsula. This species was first reported in China and is distributed in Anhui and Zhejiang provinces. We found this species on Hongdo Island in Heuksan-myeon, Shinan-gun, Jeollanam-do in the Republic of Korea. S. kiangnanense is well distinguished from other species in Korea by 4- or 5-verticillate leaves on the sterile stems and a spatulate leaf shape. We provide its morphological description, detailed illustrations, and a key to related taxa. We have given this species a new Korean name, Ip-kkot-dol-na-mul, which means flower-like leaved sedum.

Utilization of black-tailed gull (Larus crassirostris) eggs for monitoring of mercury levels in coastal areas of South Korea: Preliminary study

Studies on the monitoring of mercury accumulation using high trophic-level predators of the marine ecosystem have been scarce in South Korea. In this study, we compared the mercury concentrations of the eggs of the black-tailed gulls, a higher-order predator, breeding in two coastal areas. Breeding sites with varying mercury concentrations in land-origin freshwater fish and freshwater and marine sediments were selected in the southeastern (Hongdo Island) and western (Baengnyeongdo Island) seas. The 5-year mean total mercury concentration in eggs collected during the breeding seasons from 2012 to 2016 was higher in those collected from Hongdo than in those collected from Baengnyeongdo. This difference in mercury concentration in eggs was observed for each year. In addition, the total mercury concentration in eggs was consistently higher on Hongdo, which also had higher mercury pollution, than on Baengnyeongdo Island. These results support the suitability of black-tailed gull eggs for monitoring of mercury pollution.

Mismatching between nest volume and clutch volume reduces egg survival and fledgling success in black-tailed gulls.

A longstanding suggestion posits that parents prefer to match nest volume and clutch size (clutch volume), but few studies have tested this in colonial seabirds that nest in the open. Here, we demonstrate the effects of nest–clutch volume matching on egg survival, hatching, and fledgling success in black-tailed gulls Larus crassirostris on Hongdo Island, Korea. We show that the volume mismatch, defined as the difference between nest volume and total egg volume (the sum of all eggs’ volume in the clutch), was positively related to egg and chick mortality caused by predation, but was not significantly related to hatching success incurred by insulation during the incubation period. Although nest volume was negatively related to laying date, we found that the mismatch was positively related to laying date. Our results support the claim that well-matched nest–clutch volume may contribute to survival of eggs and chicks, and ultimately breeding success.

Trace element contamination in nestling black-tailed gulls (Larus crassirostris) in Korea.

At Hongdo Island, Gyeongsangnam-do, Korea, a breeding site of black-tailed gull (Larus crassirostris), we collected nestlings from two locations: a "reference" site (n=10) with no known source of lead contamination and "lighthouse" site (n=10) with suspected lead contamination from leaded paint. Iron concentrations in the kidney and bone, manganese in the muscle, copper in the bone, lead in the muscle and bone, and cadmium in the liver, muscle, and bone at the reference site were significantly higher than at the lighthouse. Manganese concentrations in the liver and kidney, and lead in the kidney were significantly greater at the lighthouse than at the reference site. Iron, zinc, manganese, copper, lead and cadmium concentrations had tissue-specific accumulation at both sites. Lead concentrations in 10% of livers and in 80% of kidneys at the lighthouse, and in 20% of livers from the reference were within a range considered toxic (>6.00μg/gdw in the liver and kidney). Lead concentrations in 50% of black-tailed gull nestlings at the reference and 80% nestlings at the lighthouse were greater in livers than in bones, which is suggestive of acute lead exposure. For cadmium, all liver and kidney concentrations from two sites were at a level considered background in birds. Cadmium concentrations of every sample were higher in kidneys than in livers, suggestive of chronic cadmium exposure. Lead concentrations in gull nestlings in the present study were relatively higher than other gull species worldwide, but cadmium concentrations were relatively lower.

홍도 인근 무인도서에 관한 인문사회 연구

홍도 인근 무인도서에 관한 인문사회 연구

Trace element concentrations in eggshells and egg contents of black-tailed gull (Larus crassirostris) from Korea.

Concentrations of trace elements (cadmium, lead, copper, manganese and zinc) were examined in eggs of black-tailed gulls (Larus crassirostris) from Hongdo Island, Korea to determine the difference and distribution of trace elements in eggshells and egg contents. Cadmium, lead and manganese concentrations were greater in eggshells than in egg contents. In contrast, zinc concentrations were higher in egg contents than in eggshells. Trace element concentrations followed the order: zinc > lead = manganese = copper > cadmium (eggshells) and zinc > copper > manganese > lead > cadmium (egg contents). Cadmium concentrations were relatively low (<1 μg/g dw) in egg contents and eggshells. Concentrations of cadmium, lead and copper were significantly correlated between egg contents and eggshells. This indicates that cadmium, lead and copper levels in the eggshell can reflect their levels in the egg contents. There was also a high ratio (3.2) of eggshell/egg content for lead. These results indicate that the eggshell might be useful as a bio-indicator for monitoring cadmium, lead and copper in the egg content.

Heavy metal concentrations in Black-tailed Gull (Larus crassirostris) chicks, Korea

The objectives of this study were to quantify concentrations of heavy metals in livers and stomach contents of Black-tailed Gull (Larus crassirostris) chicks from two islands in Korea. Iron and manganese concentrations were significantly higher in chick livers at Hongdo Island compared to Rando Islnad. In contrast, zinc, copper and cadmium concentrations were significantly higher at Rando Island than Hongdo Island. On Hongdo Island, Black-tailed Gull chicks at a lighthouse site had higher lead concentrations in livers and stomach contents than at a nearby reference site and stomach contents of Black-tailed Gull chicks had significantly higher lead concentrations than regurgitated diets. In Hongdo Island, manganese, lead and cadmium concentrations were significantly correlated between livers and stomach contents. Essential elements such as iron, zinc, manganese and copper concentrations from the present study were within the range reported for other seabird species including gulls. Livers of four individual gull chicks (13.3%) were at a level considered lead exposed (6–30μgg−1 dry weight), but cadmium concentrations in all specimens were within the background level (<3μgg−1 dry weight) for wild birds. Elevated lead concentrations on lighthouse site may be attributed to ingestion of paint chips and these concentrations may negatively affect chick behavior, growth and survival.

Studies of Vegetation Structure Analysis and Vegetation Transition over 25 years of Evergreen Broad-leaved Forest in Hong-Do Island

This study aims at classifying and interpreting on the vegetation structure and the vegetation transition over 25 years (between 1986 and 2010), and the correlation with the change of some conditions (the vegetation height and coverage on each layer and the climate factors as WI, CI, mean annual temperature, mean annual total precipitation etc.) in the Evergreen Broad-Leaved Forest,, Hong-Do island. The EBLF is classified into five units of vegetation (Hedera rhombea-Machilus thunbergii community (M-M comm.), Castanopsis sieboldii forest (Machilus japonica-Castanopsis sieboldii community; Raphiolepis indica var. umbellata-C. sieboldii community), community (Qa comm.), Carpinus turczaninovii community (Ct comm.), Camellia japonica stand (Cj stand)). The vegetation transition by CCA had high correlation with the height and coverage on each layer and the climate factors, and it did the succession (transition) that the M-M comm. (2010) from Mallotus japonicus community･Machilus thunbergii community･Carpinus coreana community (Cc comm.)･Aucuba japonica community (Aj comm.)･Trachelos permum asiaticum var. intermedium-Quercus acuta community (TQ comm.) (1986), the communities of C. sieboldii forest (2010) from Aj comm.･TQ comm.･Raphiolepis umbellata-Camellia japonica community (RC comm.) (1986), the Qa comm. (2010) from Ardisia japonica-Castanopsis sieboldii community (AC comm.) and TQ comm. (1986), the Ct comm. (2010) from Cc comm.･RC comm.･Aj comm.･Quercus serrata community and the Cj stand (2010) from AC comm. (1986). the height and coverage on each layer are also changed.

Difference in Black-tailed Gull (Larus crassirostris) diet during the breeding season for the last 10 years in the South Sea of Korea

Sea temperature in the South Sea of Korea has been increased over the last decades. Seabirds are sensitive to changes in food availability in marine environment. In this study, we investigate the diet of Black-tailed gulls (Larus crassirostris) during the breeding season to identify changes of marine environment and biological response such as breeding performance in the South Sea of Korea. A total of 22 fish species or family (n = 128) from regurgitates by chicks were collected on Hongdo Island in 2002 and 2012. The most important prey item was Japanese anchovies (Engraulis japonicas). Proportion of Anchovy in diet increased in 2012 (70.5%) compared to 10 years ago (27.5%). Some species were newly found in 2012: Spotted chub mackerel (Scomber australasicus), Pacific sand lace (Ammodytes personatus), White ventral goby (Acanthogobius lactipes), Silver-strip round herring, Multicolorfin rainbowfish (Halichoeres poecilopterus), Silverside (Hypoatherina tsurugae), Surfperch (Neoditrema ransonneti) and Spotnape ponyfish (Leiognathus muchalis), but not in 2002. Especially, sub-tropic fish such as Kammal thryssa (Thryssa kammalensis), and Rosefish (Helicolenus hilgendorfi) were frequently observed in the diet of 2012. These results might reflect the increase of sea temperature in the South Sea of Korea.

Molecular Detection ofAnaplasma,Bartonella, andBorreliaSpecies in Ticks Collected from Migratory Birds from Hong-do Island, Republic of Korea

Bird migration is a recurring annual and seasonal event undertaken by more than 100 species of birds in the southeast Asian and northeast Palearctic regions that pass through or remain for short periods from April to May and September to November at Hong-do Island, Republic of Korea (ROK). A total of 212 ticks (40 Haemaphysalis flava, 12 H. longicornis, 146 Ixodes turdus, 13 I. nipponensis, and 1 I. ornithophila) were collected from 65/2,161 (3.0%) migratory birds consisting of 21 species that were captured from January, 2008, through December, 2009, as part of the Migratory Birds Center, Hong-do bird banding program for studying bird migration patterns. Adult ticks were assayed individually while larvae and nymphs were pooled (1-22 and 1-6 ticks per pool, respectively) into 31 and 65 pools, respectively. Ticks were assayed for zoonotic pathogens by PCR using 16S rRNA, heat shock protein (groEL), and internal transcribed spacer (ITS) gene primers to amplify genera specific for Anapalsma, Bartonella, and Borrelia PCR amplicons. Using the 16S rRNA-based nested PCR, A. phagocytophilum (n=1) was detected in I. nipponensis collected from Zoothera sibirica and A. bovis (n=1) was detected in I. turdus collected from Emberiza chrysophrys. Borrelia turdi 16S rRNA genes (n=3) were detected in I. turdus and I. nipponensis collected from Turdus pallidus and Zoothera aurea. Borrelia spp. 16S rRNA genes (n=4) were detected in Ixodes ticks collected from Emberiza tristrami, T. pallidus, and Z. aurea. The Bartonella grahamii ITS gene (n=1) was detected by nested PCR assay in I. turdus collected from Z. aurea. These results provide insight into the potential role of migratory birds in the dispersal of ticks and associated tick-borne pathogens throughout their ranges in Asia.

Current Status of Research about Insect Fauna of Natural Reserves in Korea

Today, about 1,700,000 species of animals and plants havebeen described in the world. Nearly 1,200,000 species ofthem are animals, and three fourth (900,000 species) ofthem are insects. According to the result of the recent studyon tropical forest and other major habitats, the actualnumber of insects inhabiting on Earth is estimated to reach30 million species (Lee et al., 1994). 15,000 species ofinsects have been reported in the Korean Peninsula,including about 8,200 species in South Korea and 3,604species in North Korea. On the other hand, 30,399 specieshave been recorded in Japan located near Korea (Kwon etal., 1994). Especially, the Korean Peninsula has high insectdiversity due to its variety of nature in terms of topography,geography and hydrology characterized with a variety ofclimates for small land space, stretching north and south,rising to the east, and inclining gently towards thesouthwest. As such, a number of insect species aredistributed in our natural environment, and therefore thoseinsects play a important roles from food chain in a varietyof ecosystems as consumer, decomposer, predator orparasite, which also have influence on our human beingeither directly or indirectly.There are ten Natural Reserves in Korea including theMarado Island Natural Reserve designated on July 18 in2000, starting from the Hongdo Island Natural Reserve(Natural Monument No. 170) designated on April 7 in 1965(Table 1). Except Dokdo Island or Marado Island designatedfrom the aspect of territorial expansion in part, all otherareas were designated as the Natural Reserves for thereason of their having rare living creature required to bepreserved from the aspects of landscape and science or theirenvironment of high biodiversity. The importance of theDokdo and Marado Island Natural Reserves, however, isemerging again from such an ecological aspect that theyrecently provide resting place to rare marine living creatureliving at the coastal area, southern type species that live inthe area, or the insects that move a long distance (An,2000).Accordingly, this study is intended to compare andanalyze the characteristic of insect fauna living in the areadesignated as the Natural Reserves in Korea and therebyprovide significant fundamental data that can be used orutilized in establishing the plan of managing and preservinginsect ecosystem in the Natural Reserve.

Isolation and Characterization of 13 Microsatellite Loci from Korean Quercus acuta (Fagaceae)

Quercus acuta is an evergreen broadleaf tree that grows in the warm-temperate regions of Korea and Japan. Its habitats and populations are being destroyed, and a new northernmost limit of distribution has now been reported. To further our scientific understanding of its conservation and phylogeography, we isolated and characterized 13 microsatellite loci. An analysis of diversity was conducted among 35 individuals on Hong-do Island of Jeollanam-do, South Korea. Variability of the markers was also tested for 11 individuals from Jeju-do. At the population level, alleles numbered 2 to 12 and the observed and expected heterozygosities ranged from 0.0909 to 0.9143 and from 0.0909 to 0.9364, respectively. Those 13 loci were also tested for cross-species amplification in three other evergreen Quercus species within the same subgenus Cyclobalanopsis. In all, 6 of 13 loci could be amplified for all three species. The microsatellite markers described here provide a powerful genetics tool for population, conservation, systematics, and phylogeographic studies, not only for Q. acuta but also for other evergreen Quercus species.

Egg survival is related to the colour matching of eggs to nest background in Black-tailed Gulls

A long-standing hypothesis posits that, for species with exposed nests, a close match between the colour of the eggs and that of the nest in which they are laid should enhance egg survival, but this has rarely been tested in a rigorous manner. Here, we demonstrate the effects of egg–nest colour matching on egg survival in Black-tailed Gulls (Larus crassirostris) on Hongdo Island, Korea. We quantified the ground colour of eggshells and that of the nest background using a digital camera and computerized RGB and greyscale colour systems. We show that a close match of eggshell ground colour and nest background colour was associated with increased chances of eggs surviving through to hatching. In particular, there were strong survival advantages for eggs matching the nest colour in sites with poor concealment, whereas there was no effect of eggshell ground colour in nests that were more concealed by vegetation. Our findings support the hypothesis that egg colour functions to make eggs cryptic and that egg colouration may be a significant factor affecting egg loss.