• Journal of the Korean Society of Marine Environment & Safety
• /
• v.15 no.3
• /
• pp.173-177
• /
• 2009

A total of 3 epiphytic macroalgae were collected from eelgrass bed in Jindong Bay, and Scytosiphon lomentaria and Colpomenia sp. in Phaephyta, Gracilaria sp. in Rhodophyta occurred during study periods. For epiphytic microalgae (diatoms), Cocconeis scutellum and Cocconeis placentula were common species. Seasonal variations of epiphytic algal biomass were marked: the higher epiphytic macroalgae was 3.3 g $DW/m^2$ in November 2003; whereas epiphytic diatoms were 43,153 $cells/m^2$ in June 2003. Diversity and number of epiphytic macroalgae species were the lowest in the study area, compared with those of in other areas such as Koongyang Bay, Dongdae Bay, and Aenggang Bay. These results were therefore likely due to the severe physical characteristics of the intertidal mudflat eelgrass biological characteristics, and the deterioration of water quality.

• Ocean and Polar Research
• /
• v.28 no.3
• /
• pp.225-236
• /
• 2006

Seagrass meadows are considered as critical habitats for a wide variety of marine organisms in coastal and estuarine ecosystems. In many cases, studies on the spatial/temporal distribution of seagrass have depended on direct observations using SCUBA diving. As an alternative method fur studying seagrass distribution, an application of hydroacoustic technique has been assessed for mapping seagrass distribution in Dongdae Bay, on the south coast of Korea, in September 2005. Data were collected using high frequency transducer (420 kHz split-beam), which was installed with towed body system. The system was linked to DGPS to make goo-referenced data. Additionally, in situ seagrass distribution has been observed using underwater cameras and SCUBA diving at four stations in order to compare with acoustic data. Acoustic survey was conducted along 23 transects with 3-4 blot ship speed. Seagrass beds were vertically limited to depths less than 3.5m and seagrass height ranged between 55 and 90cm at the study sites. Dense seagmss beds were mainly found at the entrance of the bay and at a flat area around the center of the bay. Although the study area was a relatively small, the vertical and spatial distributions of the seagrass were highly variable with bathymetry and region. Considering dominant species, Zostera marina L., preliminary estimation of seagrass biomass with acoustic and direct sampling data was approximately $56.55g/m^2$, and total biomass of 104 tones (coefficient variation: 25.77%) was estimated at the study area. Hydroacoustic method provided valuable information to understand distribution pattern and to estimate seagrass biomass.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.19 no.1
• /
• pp.9-16
• /
• 2013

The growth and production of Aulichthys japonicus (6.70~15.32 cm TL) were investigated in an eelgrass bed of Dongdae Bay, Korea throughout 2006. A total 888 A. japonicus were collected with a small beam trawl. Growth in fish total length was expressed by the von Bertalanffy's growth equation as: $L_t=24.8257(1-e^{-0.5583(t+0.4816)})$. The densities, biomass, daily, annual production, and P/B ratio were $0.01{\pm}0.009/m^{-2}$, $0.17{\pm}0.16g/m^2$, $0.00006{\pm}0.00006g$ AFDW/$m^2$/day, 0.02g AFDW/$m^2$/yr, and 0.12, respectively. Monthly variation in production of A. japonicus was large; the peak occurred at July, September and November 2006 (0.000182, 0.000127 and 0.000123 g AFDW/$m^2$/day), where as the lowest value was 0.000003g AFDW/$m^2$/day at April and May 2006. Monthly change in production of A. japonicus was positive correlated with number of individuals, biomass and growth rate.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.20 no.5
• /
• pp.461-467
• /
• 2014

The growth and production of Pseudoblennius cottoides (1.80~10.01 cm TL) were investigated in an eelgrass bed of Dongdae Bay, Korea throughout 2006. A total 702 P. cottoides were collected with a small beam trawl. Growth in fish total length was expressed as: $TL=0.0539d^{0.9105}$. The relationships between total length body weight was estimated as $W=0.0079TL^3.1103$. The densities, biomass, daily, annual production, and P/B ratio were $0.06{\pm}0.062/m^2$, $0.10{\pm}0.144g/m^2$, $0.0005{\pm}0.0006g\;AFDW/m^2/day$, $0.1833g\;AFDW/m^2/year$, and 1.813, respectively. Monthly production of P. cottoides were greatly peak in May, July and September (0.0029, 0.0031 and $0.0019g\;AFDW/m^2/day$) when the biomass was high, and the lowest value in December (0.00004g AFDW/m^2/day) when the biomass was low. Monthly change in production of P. cottoides was positively correlated with biomass and temperature.

• Korean Journal of Ichthyology
• /
• v.20 no.2
• /
• pp.112-116
• /
• 2008

Feeding habits of Hippocampus mohnikei (4.1~10.4 cm SL) collected from an eelgrass bed in Dongdae Bay, Korea were studied. H. mohnikei was a carnivore fish which consumed mainly gammarid amphipods. Its diets also included a small amount of caprellid amphipods, tanaids, copepods, mysids, and eelgrass. Gammarid amphipods were the most important prey organisms to the diet of all size classes of H. mohnikei despite smaller H. mohnikei (<4.5 cm SL) fed copepods. H. mohnikei fed on larger sizes of prey as their size increased. The dietary breadth of H. mohnikei were decreased with increasing their size.

• Korean Journal of Ichthyology
• /
• v.33 no.3
• /
• pp.196-201
• /
• 2021

The Indo-West Pacific pipefish, Hippichthys penicillus was newly recorded from Korean waters based on a single specimen (124.5 mm SL) collected from a lower reach of creek of the Namhaedo Island flowing into Dongdae Bay. It is separable from congeners in having a longer snout and unique configuration of principle body ridges including discontinuous superior trunk and tail ridges and straight lateral trunk ridge ending near anus. A new Korean name, "Huin-jeom-sil-go-gi", is proposed for the species.