• 제목/요약/키워드: Reefs

검색결과 190건 처리시간 0.023초

해조류 이식형 인공어초의 수리적 안정성에 관한 실험적 검토 (Experimental study on new artificial reef for hydraulic stability)

  • 신범식;정현준;김규한
    • 한국산학기술학회논문지
    • /
    • 제15권1호
    • /
    • pp.555-560
    • /
    • 2014
  • 우리나라 연안생태계는 백화현상(갯녹음)에 의한 해조류의 감소와 어패류 등 어업자원의 감소로 인해 연안역의 황폐화에 직면해 있다 새로운 인공어초의 새로운 유형의 안정성을 평가하기 위해 본 연구에서는 2차원 단면수조를 이용하여 새롭게 개발된 인공어초의 설치수심에 따른 재현파고, 주기, 흐름 등 외력을 변화시켜 해조류 이식형 어초의 안정 조건이 되는 한계치를 구하고, 설계외력(파랑, 흐름 등)의 안정성에 대한 검토를 수행하였다. 본 연구 결과는 새로운 인공어초의 설계 및 실해역에 시공하기 위해 구조물의 안정성을 사전에 검토할 수 있는 있는 기초자료를 제공할 수 있을 것으로 판단된다.

충청남도 녹도해역의 인공어초 효과와 상태에 관한 연구 (A Study on the Research Condition and Efficiency of Artificial reefs of Rokdo Sea region of Chungnam Province)

  • 박종수;서만석;김지현
    • 수산해양교육연구
    • /
    • 제13권1호
    • /
    • pp.87-98
    • /
    • 2001
  • 1. The bottom mean size of the research area had been showed 86.8% in, 13.2% in mud artificial sector, but and 82.4% in mud at comparative sector. 2. The water temperature had been showed $11.2{\sim}12^{\circ}C$ in surface, $10.9^{\circ}C$ in mid layer, $10.6{\sim}10.8^{\circ}C$ in lower layer. also, The salinity had been showed $31.85{\sim}31.95_{psu}$ in surface, $31.82{\sim}31.97_{psu}$ in mid layer, $31.85{\sim}31.97_{psu}$ at lower layer. The transparency was showed 3.6~5.6m. 3. The conservation condition of reefs was partially grooved and buried the lower part of reefs established '95~'96years but was good condition generaly. 4. The attached fauna has been appeared fisheres botanical specise 6, fisheries animate species 5. 5. The lure of fisheres has been appeared 17 species in reefs sector, 10 species in comparative sector(natural fishing ground). 6. The catchs of C.P.U.E by fishery was catched 2.2~3.3 times in reefs sector than the natural fishing ground. but the individuals was much catched in traps. The jumbo type reefs gill netter were much catched in square artificial reefs. The weight of fishery was much captured in jumbo type reefs.

  • PDF

인공어초 사후관리 현황과 발전방향 (Management after installation of artificial fish reefs -Present Condition and Development Scheme-)

  • 안승환;김동선;박경원;이성일
    • 해양환경안전학회:학술대회논문집
    • /
    • 해양환경안전학회 2005년도 추계학술대회지
    • /
    • pp.139-141
    • /
    • 2005
  • 인공어초의 기능을 복원하기 위하여 어초시설과 함께 어초어장의 사후관리는 중요하다. 전남 여수지역 6,142ha에 시설된 인공어초어장에 대하여 양방향음향탐사기(Side Scan Sonar) 및 잠수조사를 실시하고 어초의 시설상태, 생물상, 폐그물량을 조사하였다. 또한 보다 낳은 인공어초 사후관리 방법을 알아보고자 하였다.

  • PDF

Species-specific biomass drives macroalgal benthic primary production on temperate rocky reefs

  • Spector, Michael;Edwards, Matthew S.
    • ALGAE
    • /
    • 제35권3호
    • /
    • pp.237-252
    • /
    • 2020
  • Temperate rocky reefs dominated by the giant kelp, Macrocystis pyrifera, support diverse assemblages of benthic macroalgae that provide a suite of ecosystem services, including high rates of primary production in aquatic ecosystems. These forests and the benthic macroalgae that inhabit them are facing both short-term losses and long-term declines throughout much of their range in the eastern Pacific Ocean. Here, we quantified patterns of benthic macroalgal biomass and irradiance on rocky reefs that had intact kelp forests and nearby reefs where the benthic macroalgae had been lost due to deforestation at three sites along the California, USA and Baja California, MEX coasts during the springs and summers of 2017 and 2018. We then modeled how the loss of macroalgae from these reefs impacted net benthic productivity using species-specific, mass-dependent rates of photosynthesis and respiration that we measured in the laboratory. Our results show that the macroalgal assemblages at these sites were dominated by a few species of stipitate kelps and fleshy red algae whose relative abundances were spatially and temporally variable, and which exhibited variable rates of photosynthesis and respiration. Together, our model estimates that the dominant macroalgae on these reefs contribute 15 to 4,300 mg C m-2 d-1 to net benthic primary production, and that this is driven primarily by a few dominant taxa that have large biomasses and high rates of photosynthesis and / or respiration. Consequently, we propose that the loss of these macroalgae results in the loss of an important contribution to primary production and overall ecosystem function.

동해안 사질지반에 시설된 인공어초 3종의 매몰 특성 (Settlement Characteristics of Three Type of Artificial Reefs on Sandy Bottom in the Eastern Coast of Korea)

  • 김대권;김완기;손용수;윤장택;공용근;김영대;이지현
    • Journal of Advanced Marine Engineering and Technology
    • /
    • 제32권2호
    • /
    • pp.359-364
    • /
    • 2008
  • Using multi beam echo sounder, side scan sonar and scuba diving equipment, ceramic type, uneven type and semicircle-ramus type reefs into sandy bottom were ascertained, the depth of submersion in 7.2-10.3m on the coast of Gangneung, East of Korea, forty uneven type artificial reefs(AR) were totally buried into the sandy bottom. Two of five semicircle-ramus type ARs had only of their top area exposed. For most of the 45 ceramic reefs, only the upper 25-150cm of ARs were visible. The burial pattern is different in west and east side of the reefs, where the east side is deeply buried compared to the west side. From these results. it is recommended that sufficient analysis of bottom structure and materials especially in the sandy sea area should be undertaken in order to determine the best type of artificial reefs to be deployed and the best location for depoloyment.

제주 신양리 연안 인공어초 주변해역에서 서식하는 어류의 종조성 및 계절변동 (Seasonal variation and species composition of fish species in artificial reefs in the Shinyang-Ri coastal waters off Jeju island, Korea)

  • 김재우;김하원;허성회;곽석남
    • 수산해양기술연구
    • /
    • 제47권2호
    • /
    • pp.118-127
    • /
    • 2011
  • This study was investigated seasonal variation and species composition of fish species at artificial reefs (octangle three-stage compartment type and dice type)and natural rock in the Shinyang-Ri coastal waters off Jeju Island with visual census method in January 2009, April 2009, July 2009, September 2009, December 2009, March 2010, June 2010, and September 2010. A total of 44 fish species was occurred, and the dominant fish species were Apogon semilineatus, Chromis notata, Trachurus japonicus, Sebastes thompsoni and Apogon doederleini. The number of individuals of fishes was higher at April 2009 and March 2010, however, lower at June 2010 and September 2010. The number of fish speices was higher at artificial reefs than those of at natural rock. Apogon semilineatus was dominant at octangle three-stage compartment type and the dice type artificial reefs, whereas Chromis notata was for natural rock. These results indicated that artificial reefs were good habitats for a variety of fish species in the Shinyang-Ri coastal waters off Jeju Island.

수영만 인공어초 해역에서 소너에 의한 어군의 유영행동 추적 (Acoustic Tracking of Fish Movements in an Artificial Reef Area Using a Split-beam Echo Sounder, Side-scan and Imaging Sonars at Suyeong Man, Busan, Korea)

  • 이대재
    • 한국수산과학회지
    • /
    • 제46권3호
    • /
    • pp.273-281
    • /
    • 2013
  • The movement patterns of fish aggregations swimming freely near artificial reefs on August 24, 2006, at Suyeong Man, Busan, Korea, were acoustically investigated and analyzed. Acoustic surveys were conducted using a 70kHz split-beam echo sounder, 330 kHz side-scan sonar and a 310 kHz imaging sonar. Algorithms for tracking the movement of fish aggregations swimming in response to artificial reefs were developed. The travel direction and the swimming speed for two aggregations of fish were estimated from the trajectory orientations of echo responses recorded by the imaging sonar.The first group was floating just above the reef structure, while remaining in the midwater column, and the second group was swimming through and around artificial reefs near the seabed. The mean swimming speed was estimated to be 0.40 m/s for the midwater fish aggregation and 0.17 m/s for the bottom aggregation close to artificial reefs. These results suggest that the swimming behavior of fish aggregations passing close to artificial reefs near the seabed displayed a slower moving pattern than fish floating just above the reef structure in the midwater column.

통발 어구를 이용한 서해 경기만 사각형어초 시설의 효과 평가 (Evaluation of the effect of cubic artificial reefs in Kyonggi Bay, west coast of Korea by using fish trap)

  • 유재원;이만우;이창근;김창수;김정수;홍재상
    • 수산해양기술연구
    • /
    • 제43권2호
    • /
    • pp.126-139
    • /
    • 2007
  • In the autumn of 2000 and spring of 2001, field surveys were conducted to estimate the effectiveness of artificial reefs (type cube, $2{\times}2{\times}2m^3$) that were established in the four islands of Bangnyeong, Socheong, Daeyeonpyeong and Ganghwa in Kyonggi Bay, the west coast of Korea during 1995 and 1996. The condition of reefs was examined through SCUBA diving and a side-scan sonar. Much of the reefs in Daeyeonpyeong and Ganghwa area were buried in bottom sediment. Despite an intensive search in Bangnyeong area, even a cluster of reefs was not found and most of them seemed to be buried by sand waves. Thus an appropriate investigation on the sediment transport should be included in pre-assessment for the expected performance and protection of artificial reefs. Distribution of average CPUE in natural fishing ground (control) was estimated by bootstrapping simulation and possible comparison of CPUE between control and reef areas (treatment) were made in Bangnyeong and Socheong (Experiment I). Positive reef effect was detected in Socheong but CPUE of treatment in Bangnyeong was varied between or lower than the 99% CPUE confidence intervals of the control. Control/treatment abundance and biomass of fishes and invertebrates were tested by paired t-test and sign test (Experiment II). Only four cases among 22 showed significant positive effect. Based on the results, the cube artificial reef in Socheong was inferred as an affirmative one. Floor type was hypothesized to be one of the probable agents in determining the effectiveness of artificial reefs.

Spatial and temporal dynamics of the abundance of crustose calcareous algae on the southernmost coral reefs of the western Atlantic (Abrolhos Bank, Brazil)

  • Amado-Filho, Gilberto M.;Bahia, Ricardo G.;Mariath, Rodrigo;Jesionek, Michel B.;Moura, Rodrigo Leao;Bastos, Alex C.;Pereira-Filho, Guilherme Henrique;Francini-Filho, Ronaldo Bastos
    • ALGAE
    • /
    • 제33권1호
    • /
    • pp.85-99
    • /
    • 2018
  • Crustose calcareous algae (CCA) constitute one of the main reef builders on the Abrolhos Bank, Brazil. Once CCA taxonomy is locally understood, differences in growth-forms may be useful for the delimitation of taxa using characteristics such as the presence or absence of surface protuberances. Here, growth-forms were used to identify and quantify the most common CCA taxa on the shallow reefs (3-10 m) of the Abrolhos Bank to determine possible changes in the CCA community over a period of 10 years, and the ecological significance of CCA to local reefs was interpreted. The CCA assemblages were surveyed from 2006-2015 by using fixed photoquadrats at four sites in the inner (10-20 km from the mainland) and mid-shelf reefs (40-75 km from the mainland). The five most common CCA taxa were Pneophyllum conicum, the Lithophyllum kaiserii / Lithophyllum sp. complex, Melyvonnea erubescens, the Hydrolithon boergesenii / Porolithon onkodes complex and Peyssonelia sp. The overall mean CCA cover on the reefs was 20%. A comparison with a previous monitoring study in the same region indicated that the CCA cover nearly doubled from 2003-2008 to 2006-2015. This study reveals that the coral-killing species P. conicum dominated CCA flora on the shallow Abrolhos reefs in the last decade, and the local specific abundance of CCA slightly fluctuated over time and was species- and site-specific. The information obtained in this study contributes to the understanding of the ecology of the key calcifying components of the Abrolhos reefs and provides a useful baseline for exploring the responses of CCA to future environmental changes.

갯닦기 전후의 해중림초의 해조상과 시험 부착판에서의 해조류 초기 천이 (Changes in Marine Algal Flora settled on the Artificial Seaweed Reefs Before and After Rocky Cleaning and the Early Succession of the Seaweeds attached to the Test Panels)

  • 김태연;곽철우;정의영;김영식
    • 수산해양교육연구
    • /
    • 제25권6호
    • /
    • pp.1336-1347
    • /
    • 2013
  • The marine algal flora assemblages settled on the artificial seaweed reefs in Jeju-do before and after rocky cleaning were investigated during summer and the early succession of seaweeds attached to the test panels on the structures of the artificial reef after rocky cleaning were observed by visual observations and under the dissecting microscope in order to evaluate the effects of this rocky cleaning operation. Species composition and algal biomass on the Bboolsamgak-typed seaweed artificial reefs before and after rocky cleaning were measured and compared before and after rocky cleaning. Before rocky cleaning in July 2012, only nine algal species had existed on the Bboolsamgak-typed seaweed artificial reefs, however, twenty algal species occurred on the seaweed artificial reefs after rocky cleaning in July 2013. Particularly, 15 species among them in July 2013 were not found in July 2012 and they seemed to occur newly on the artificial reefs. A large quantity of algal biomass increased in July 2013 after rocky cleaning. Based on the importance value, there was a drastic change in the dominant species between July 2012 and July 2013 after rocky cleaning. By dissecting micrographs, an epiphytic diatom, Licmophora sp. and flagellates, were observed on the 9th day. A chlorophyte, Ulothrix flacca was observed after 14 days, Ulva pertusa, Bryopsis pulmosa, crustose coralline algae, and Cladophora spp. were after one month. After two months, a significant species succession was observed from three previous chlorophyte species to crustose coralline algae existed as a dominant species on the panels. In this study, however, any brown algae were not found until three months in the early seaweed succession. All above results indicates that the rocky cleaning is a very efficient method for the establishment of macroalgal assemblages on the artificial reefs.