Factors Controlling Temporal-Spatial Variations of Marine Environment in the Seomjin River Estuary Through 25-hour Continuous Monitoring

Abstract

In order to elucidate temporal variations of temperature, salinity, pH, dissolved oxygen (DO), suspended particulate matter (SPM), dissolved inorganic nutrients, and chlorophyll a, we performed 25-hour continuous monitoring in the Seomjin River Estuary in March (dry season) and July (rainy season) 2006. We also investigated spatial variations of marine environmental parameters across a saline gradient. In the Seomjin River Estuary, continuous monitoring results revealed that salinity variations were mainly affected by tidal cycle in the dry season and by river discharge in the rainy season. In the dry season, the spatio-temporal distribution of dissolved inorganic nutrient (nitrate, nitrite, and silicate) concentrations showed a good correlation with tidal cycle. While nutrient concentrations in rainy season showed not much variance in time. There were 6 and 4 times higher dissolved inorganic nitrogen and phosphorus concentrations in the rainy season than those in the dry season, respectively. Silicate concentration was 43 times higher in the rainy season than that in the dry season. Chlorophyll a concentration was higher in the dry season than that in the rainy season showing high nutrient concentrations. The results of this study, spatio-temporal variations of marine environmental factors are determined by both tidal cycle and river discharge. It seems that chlorophyll a concentration is related to the river discharge than dissolved inorganic nutrient distribution.

Dominance of Autochthonous Phytoplankton-Derived Particulate Organic Matter in a Low-Turbidity Temperate Estuarine Embayment, Gwangyang Bay, Korea

“…The low SPM concentration in the river discharge suggests that the effect of stratification on turbidity is negligible. Indeed, a previous 25-h continuous monitoring study in this estuary showed no correlation between SPM concentration and the tidal cycle (Park et al, 2012). Water-column-depth variability, due to tidal shallowing and deepening, would be expected to influence wind-wave resuspension, especially in winter when the wind speed peaks.…”

“…Great spatial variations of NO 3 − and SiO 2 concentrations along a salinity gradient, and high N:P and Si:P ratios (∼100 compared to Redfield ratio of ∼16) at the oligohaline zone suggest a eutrophic condition in the estuarine channel due to large anthropogenic nitrogen and silicate inputs by river discharge (Kwon et al, 2001;Park et al, 2012). Rapid decreases in NO 3 − and SiO 2 concentrations as well as high PP at the oligo-and euryhaline zone of the estuarine channel suggest active biological removal, diffusion and dilution by mixing with polyhaline deep-bay water.…”

Distribution and seasonal variations of fisheries resources captured by the beam trawl in Namhae island, Korea

“…. 본 연구 해역에 대한 이전 연구는 섬진강 하구 에 서식하는 잘피 분포 현황 및 연안 해수의 수 질 평가 (Kim et al, 2010), 남해도 서쪽 연안 정 점을 포함하는 남해도 전역의 생물학적 평가법 및 아무르 불가사리를 이용한 수질평가 연구 (Yu et al, 1998;Yu et al, 1999), 섬진강 하구해역 의 식물플랑크톤의 제한 영양염 평가 (Kwon et al, 2002), 시공간적 해양환경 변화 조절 요인 연 구 (Park et al, 2012) Kwak, 1998;Kwak et al, 2008 (Chyung, 1977;Kim et al, 1995;Cha et al, 2001;Hong et al, 2006 (Fig. 6).…”