본 집쥐 퇴치 계획은 대한민국 최대 슴새 번식지 및 흑비둘기 서식처로 천연기념물 제333호로 지정되어있는 제주특별 자치도 소재(33°55′13.04″N, 126°38′19.98″E) 무인도서인 사수도 내 집쥐 퇴치를 위해 이루어졌다. 구제 연구는 2015년 11월부터 2021년 2월까지 총 12차례 진행되었고, 조사는 섬 전역을 천천히 배회하며 출발지점과 도착지점을 동일하게 하여 조사하는 선조사법을 이용하였다. 이 때 확인된 배설물, 터널 등 Rattus norvegicus 흔적 주변에 포획트랩 을 설치하였다. 그 결과 매 차시 최소 2개체 ~ 최대 6개체가 포획되던 개체가 마지막에는 포획되지 않았다. 집쥐가 사수도에 유입된 경로는 과거 레저 및 어업을 위해 출입하는 배를 통하여 유입되었을 것으로 추정하고 있다. 2006년 집쥐로 인한 슴새의 피해가 확인된 후 철저한 경비를 통하여 사수도 출입을 엄격히 금하고 2013년 해양정화 사업과 2015년부터 지속된 포획을 통하여 구제가 성공적으로 이루어지고 있는 것으로 판단된다. 본 상태 유지 및 관리를 위해서 앞으로 새로운 집쥐의 유입을 제어하기 위하여 지속적이고 철저한 출입관리를 이어가 출입자를 엄격히 통제하는 등의 보존 관리방안이 필요하다 할 수 있다.
본 연구는 제주지역 성인들의 부정적 정신적 습관 성향을 파악하고, 이에 영 향을 미치는 다양한 변인들의 영향력을 분석함으로써 성인들의 건강한 정신적 습관 확립을 위한 자료를 제시하는 데 그 목적이 있었다. 본 연구는 이러한 연구 목적을 달성하기 위해 무력감 및 불안 성향, 자기중심적 인식 성향, 감정회피 및 자기도피 성향, 그리고 부정적 판단 성향을 4가지 부정적 정신적 습관 성향으로 구분하였고, 독립변인들로는 인구사회학적 특성, 심리적 특성, 사회적지지 특성 및 환경적 스트레스 특성을 포함하였다. 본 연구는 연구목적을 위해 설문조사를 실시하였는데, 조사대상자는 만 19세 이상 60세 미만 제주지역 성인 800명이었 으며, 부실응답 등을 제외한 총 728부를 최종 분석 자료로 사용하였다. 본 연구의 주요한 결과는 다음과 같다. 첫째, 본 연구에서 구분한 성인의 부정 적 정신적 습관 성향은 전체적으로 높은 수준은 아니었으나 세부적인 실태분석 결과는 정신적 습관 성향을 대비한 교육의 필요성을 시사하였다. 둘째, 성인의 부정적 정신적 습관 성향은 전체적으로 볼 때 각 성향별로 영향을 미치는 변인 에 차이가 있었으나, 심리적 특성, 사회적 특성, 그리고 환경적 특성이 중요한 영향 변수로 나타나 이러한 변인들을 고려한 교육프로그램의 개발과 지원이 필 요함을 보여주었다.
2021년 4월부터 8월에 제주시의 비닐하우스에서 재배되는 목이버섯에서 거저리 일종이 발견되었으며, 그를 동정한 결과 제주진주거저리 (Platydema takeii Nakane, 1956)로 확인되었다. 상업적으로 재배되는 버섯에 있어서 거저리 해충으로 인한 우리나라의 첫 번째 피해 사례이다. 여 기서는 이 해충의 피해 증상과 성충 및 유충의 진단형질을 제공하고자 한다.
To isolate aerobically and identify the diversity of halophilic bacteria in the soil around two ports, Daepopogu and Hwasun Port, on Jeju island, a total 46 halophilic bacteria strains were isolated and phylogenetically analysed. The isolated strains were divided into 3 phyla, 8 families, 16 genera and 23 species. The main taxa was the Bacilli class, which included 50.0% of the strains with 3 families, 10 genera and 15 species of Bacillaceae, Exiguobacterium_f and Planococcaceae. The second taxa was the Gammaproteobacteria class, which included 45.7% of the strains with 4 families, 5 genera and 7 species of Aeromonadaceae, Halomonadaceae, Marinobacteraceae and Vibrionaceae. The isolated strains were tested for hydrolytic enzymes, amylase, lipase and protease activity, and 31 strains showed activity of at least one enzyme. Furthermore, auxin activity was determined in 7 strains. This study showed that the isolated strains have possible applications in the food and agricultural industries and have importance as a genetic resource in Korea.
PURPOSES : The objective of this study is to develop regression models for surface distress (SD), rut depth (RD), and international roughness index (IRI) of Jeju Island local road by analyzing the correlations between the pavement performance and its influencing factors. METHODS : First, the differences between pavements in inland Korea and Jeju Island in terms of performance and influencing factors were investigated. Influencing factors were assigned to pavement sections on Jeju Island using the inverse distance weighting method, and the correlations between the pavement performance and influencing factors were analyzed. As a result, maximum temperature, heat wave days, annual temperature range, precipitation days, precipitation intensity, ESAL, etc. were determined as independent variables for the pavement performance prediction models. Multiple regression analysis was performed to develop the pavement performance models using the selected independent variables.
RESULTS : The RD, maximum temperature, and precipitation days were determined to be the independent variables for the SD predictive model. The SD, maximum temperature, annual temperature range, heat wave days, and precipitation days were selected as independent variables of the RD prediction model. In addition, the RD, annual temperature range, heat wave days, precipitation days, and ESAL were selected as independent variables for the IRI prediction model.
CONCLUSIONS : As a result of the study, an actual forecast model for SD, RD, and IRI was developed. Based on this model, it is possible to estimate the predictive value of the missing performance data in the studied interval. If the factors affecting performance are managed in terms of maintenance beyond a certain level, it can help those responsible for road maintenance to rationally select the maintenance method and timing.
The purpose of this study is to provide information about annual variations in catch size and changes in reproductive biology in the common octopus, Octopus vulgaris, a commercially important species in Jeju Island. Samples were collected from coastal waters of Jeju Island, Korea by coastal trap fishery from January to November 2021. Octopus vulgaris have been decreasing in this region since 1984. The mantle length (ML) ranged from 4.5 to 17.8 cm and body weight (BW) ranged form 88.5 to 2,657.5 g. A χ 2 -test revealed that the number of males was significantly greater than females (χ 2 = 32.712, df = 10, P<0.05). Mature females were found from January to July and male occurred January to August. The gonadosomatic index value was higher from July to August than other months. The relationship between mantle length and body weight was BW = 2.4527ML 2.3139 (female) and BW = 2.6785ML 2.3159 (male). At 50% group maturity, female and male average weight was estimated to be 554.7 g and 330.6 g, respectively.
As a series of basic research to draw the pilot design measures for developing the habitat apparatus of Sulculus diversicolor supertexta inhabiting the coastal area of Jeju island, this study conducted a water tank experiment to understand the habitat marine environment of Sulculus diversicolor supertexta and the preference of habitat space focusing on the research fisheries performing the discharge of marine products. In the composition degree of marine algae in both fisheries, Donggwi-ri showed the highest gulfweed (79.3%) as brown algae and there were some coralline algae (17.2%) as red algae. Hansu-ri yielded the highest gulfweed (48.1%) as brown algae, which was followed by sea lettuce (10.4%) as green algae. In the preference of habitat space, the shelter angles 40° showed the highest adhesion as number of 82.9, which was followed by 60° and 70° as 69.2 and 68.2 respectively (P<0.05) by reviewing the environmental characteristics of habit of Salculus diversicolor supertexta in the coastal fishery of Jeju Island, when considering the adhesion rate in each of five shelters with different angles. In the future, there should be continuous research and monitoring for designing the fish shelters suitable for the coastal fisheries of Jeju island, and it would be also necessary to add the field-centered sustainable concrete research.
This study assessed the levels of water qualities and microbials contamination of inland olive flounder farms in Jeju in the summers from 2015 to 2017. Three farms (A-C) located in a concentrated area using mixing coastal seawater and underground seawater and one farm (D) located in an independent area using only coastal seawater were selected. Total ammonia nitrogen (TAN) reached a maximum of 0.898 ± 1.024 mg/L as N in the coastal seawater of A-C, which was close to the limit of the water quality management goal of the fish farm. TAN in the influent from A-C was up to three times higher than that of D, so that the discharged water did not spread to a wide range area along the coast and continued to affect the influent. TAN of the effluent in A-C increased by 2.7-4.6 times compared to the influent, resulting in serious self-pollution in the flounder farm. Heterotrophic marine bacteria in the influent of A-C was about 600 times higher than D, and the discharge of A-C was increased by about 30 times compared to the influent.
In September and October 2020, combined acoustic and trawl surveys were conducted in the northwestern sea of Jeju Island. In the survey area, a region, so called Jeju region, was designated to esimate the biomass of chub mackerel and jack mackerel using a trawl survey method and frequency difference method. In the September survey, the weight ratios of jack mackerel and chub mackerel to the total catch were 24.6% and 2.8%, respectively, and in the October survey, those ratios were 24.9% and 20.7%, which were used to calculate their biomass (trawl survey). Using the frequency difference range (–8 to –3dB) corresponding to two species in 120 and 200 kHz, their biomass was estimated (frequency difference method). As a result, the biomass of two species from the trawl method was 3252.3 tons in September and 5777.0 tons in October. The estimated biomass by the frequency difference method was 4926.6 tons in September and 7521.5 tons in October. It was the first trial to estimate the biomass of two species using the trawl and frequency differencing methods in South Korea although there were some differences between two methods. In addition, horizontal distributions of acoustic backscattering strength over the entire survey area were mapped.
Using environmental DNA (eDNA) in the fisheries and oceanography fields, research on the diversity of biological species, the presence or absence of specific species and quantitative evaluation of species has considerably been performed. Up to date, no study on eDNA has been tried in the area of fisheries acoustics in Korea. In this study, the biomass of a dominant species in the northwestern waters of Jeju Island was examined using 1) the catch ratio of the species from trawl survey results and 2) the ranking ratio of the species from the eDNA results. The dominant species was Zoarces gillii, and its trawl catch ratio was 68.2% and its eDNA ratio was 81.3%. The Zoarces gillii biomass from the two methods was 7199.4 tons (trawl) and 8584.6 tons (eDNA), respectively. The mean and standard deviation of the acoustic backscattering strength values (120 kHz) from the entire survey area were 135.5 and 157.7 m 2 /nm 2 , respectively. The strongest echo signal occurred at latitude 34° and longitude 126°15’ (northwest of Jeju Island). High echo signals were observed in a specific oceanographic feature (salinity range of 32-33 psu and the water temperature range of 19-20℃). This study was a pilot study on evaluating quantitatively aquatic resources by applying the eDNA technique into acoustic-trawl survey method. Points to be considered for high-quality quantitative estimation using the eDNA to fisheries acosutics were discussed.
귤굴나방은 제주도 감귤원에서 경제적으로 중요한 해충이지만, 상대적으로 월동생태와 관련된 연구는 부족하다. 본 연구에서는 귤굴나방이 월동과 관련하여 다음 해 초기개체군 발생과 어떻게 연결되는지 발육단계별 저온 실내실험과 야외실험 및 노지 감귤원 포장조사를 통하여 구명하였다. 연구 결과, 동일한 저온 조건에서 귤굴나방의 발육단계에 따라 생존기간의 유의한 차이가 있었으며 성충이 번데기보다 더 오래 생존하는 것으로 나타났다. 귤굴 나방 성충과 번데기를 야외 감귤원에 접종한 후 생존기간을 평가한 결과, 서귀포지역에서 성충은 다음 해 3월 24일까지 생존하였다. 이는 일반적으로 서귀포지역의 봄순 발아가 3월 중순에 시작된다는 사실을 고려했을 때 성충태로 월동한 귤굴나방이 다음 해 초기개체군을 형성할 가능성이 높다는 것을 의미한다. 반면에 번데기의 경우 제주시와 서귀포에서 1월을 넘기지 못하고 모두 사망하였다. 또한, 노지 감귤원 내 귤굴나방 발육단계별 밀도조사에서 다음 해 봄까지 노지 감귤원에서 생존한 번데기는 없었던 반면 성충은 모든 과원에서 지속적으로 발견되었다. 따라서 결과를 종합하여 판단해 볼 때, 제주도의 노지 감귤원에서 귤굴나방은 성충태로 월동하는 것으로 판단되며, 번데기의 경우 신초에 형성된 용방에서만 생존할 수 있다는 제약이 있기 때문에 겨울철 동해 피해를 받기 쉬운 신초에서 월동 후 다음 해 초기개체군 형성에 기여하는 것은 쉽지 않을 것으로 판단된다.
본 연구는 전자 센서를 이용하여 다양한 추출방법에 따른 무 추출물들의 향미 특성을 조사하였다. 무의 신맛은 무 흰색 부위의 열수 추출물이 6.9의 센서 값을 나타내어 가장 높았다. 신맛은 8.0의 센서 값을 나타내어 무 초록색 부위의 콜드 브루 추출물이 가장 높았다. 감칠맛은 무 흰색 부위의 열수 추출물이 8.3의 센서 값을 나타내어 가장 높았다. 단맛은 무 초록색 부위의 콜드 브루 추출물이 6.8 의 센서 값으로 가장 높은 값을 나타내었고, 쓴맛은 무 초록색 부위의 고온 가압 추출물이 7.5의 센서 값으로 가장 높은 값을 나타내었다. 전자코를 이용하여 무 추출물들에서 총 16개의 휘발성 향기성분을 확인하였다. 무 추출물 속 휘발성 향기성분들 중 methanethiol이 주요한 향기성분으로 확인되었다. 본 연구에서 확인된 결과들은 무 추출 물의 향미 특성에 대한 기초 연구 자료로 활용될 수 있을 것으로 판단된다.
This paper investigates the current status of Jeju special self-governing province (JSSGP)’s water infrastructure and recommends directions for improvement. JSSGP relies on groundwater for most of its water resources. Recently, water usage has been steadily increasing due to the increase of residents and tourists while the quality of groundwater has been steadily worsening. Deterioration in water quality of groundwater can be seen through the increase in concentration of nitrate nitrogen and microorganisms. To overcome such problems, water consumption must be reduced by water demand management in all fields including residential and agricultural water use. The quality of water resources should be preserved through the management of pollutants. For efficient management of water resources, great efforts should be made to reduce the leakage rates in household and agricultural water, which is currently at the highest level in the country. Furthermore, diversification of water intake sources other than groundwater is needed, especially for agricultural water supply. For water and sewerage facilities, compliance with drinking water quality standards and discharge water quality standards must be achieved through the optimization of operation management. This process requires recruiting professionals, improving existing workers' expertise, and improving facilities.
PURPOSES : The purpose of this study is to evaluate an asphalt mixture via field application to utilize basalt aggregates produced on Jeju Island for a warm mix asphalt (WMA).
METHODS : Using commercially available WMA additives, an indoor experiment is conducted on low- and high-void aggregates among basalt aggregates on Jeju Island. The physical properties of the WMA mixture are evaluated using one solid type and two liquid types of WMA additive. To evaluate the applicability of the WMA additives, air void, saturation, aggregate void, Marshall stability, flow number, indirect tensile strength, and toughness tests are performed. For the field application of WMA using basalt aggregates, three types of pavements (HMA, WMA-Solid, and WMA-liquid) are constructed. When applying the pavements in the field, an anti-stripping agent is incorporated to improve the water resistance while considering the characteristics of the basalt aggregate. Samples are acquired via plant and field coring to evaluate the properties of the materials applied in the field.
RESULTS : In the indoor test for analyzing the applicability of the commercialized WMA additives to basalt aggregates, all tests except the indirect tensile strength test show results that satisfy the standards. All test results, including that from the indirect tensile strength test, satisfy the standard values in the test that uses the sample material obtained from the plant. Similarly, in the test with field cores, all test results satisfy the standard values. Therefore, the experimental value in the field application is generally higher than the test value in the indoor experiment. It is inferred that this is due to the difference between the basalt aggregates used in the indoor and field experiments, as well as the addition of the anti-stripping agent.
CONCLUSIONS : Basalt aggregates produced on Jeju Island can be used for WMA pavements, as demonstrated via indoor experiments and field applications. However, owing to the characteristics of basalt aggregates, a method for improving water resistance should be considered, and tests to determine the indirect tensile strength should be performed using various basalt aggregates. In addition, because various basalt aggregates exist owing to the diverse geology characteristics of Jeju Island, they should be evaluated via more experiments and field applications.