Vypeen, an island of Cochin estuarine system, acts as the spawning site of several marine and estuarine fishes. We assumed that, physical process (upwelling) make changes in hydrography and the production of chlorophyll a in coastal waters off Vypeen. These alterations can influence the zooplankton abundance and copepod community structure in that area. For justifying this hypothesis, samples were collected from Vypeen at 10 m and 30 m locations during January (pre-southwest monsoon), August (late-southwest monsoon) and November (post-southwest monsoon) 2014. During August, subsurface water column was cool, nutrient rich and less oxygenated (signatures of upwelling) than in November and January. Maximum concentrations of nitrate and chlorophyll a were recorded during August. In the present study, 15 zooplankton groups were recorded; of which copepods were the most predominant group (73%-90%). Copepod density in the present study ranged between 527.2 ind./m³ and 5 139.2 ind./m³. Totally, 37 copepods species were reported in present study and copepod species richness was higher during January. The abundance of zooplankton and copepods was high in August during late-southwest monsoon. These variations were closely associated with the coastal upwelling in August and weakening of moderate upwelling in November. In SIMPER analysis, it was found that the copepods species distribution was similar within season and dissimilar between the three seasons. Moreover, the higher abundance of upwelling indicator species Temora turbinata was recorded in August, which confirms the signs of seasonal upwelling in Vypeen. The present study emphasized on the influence of hydrographical parameters associated with physical process, in governing the copepod community organization of the Vypeen Island.

In order to determine the relative aging status ofupwelled or vertically mixed water in the northern Taiwan Strait,a recently developed method of calcularing the degree of nutrient consumption (DNC) was employed.Upwelling was detected at a water depth of about 75 m in summer.Bottom waters in the aphoric zone and newly-upwelled waters in the euphoric zone were found to be low in terms of their DNC.In general,a low DNC was noted alongside the other traditional upwelling indicators,such as lower temperature and degree of oxygen saturation,but higher salinity,apparent oxygen utilization,nutrient contents and chlorophyll-a.Enhanced vertical mixing,but without an apparent upwelling signal,was detected near the same location in winter.

Based on the data obtained from oceanographic surveys at the central and northern parts of the Taiwan Straft during the pgriod from 1983 to 1988, it is showed that the nutrient content in the coastal and bottom waters is relatively high with an upward and offward decrease, and that the upwelling in the Fujian coastal area controls the distribution of nutrients in summer.The upwelling water is characterized by 2.29 μmol/dm³ of nitrate; 2.83 μmol/dm³ of silicate; 0.20 μmol/dm³ of dissolved inorganic phosphate, respectively.Significant rnrreJation between nutrients and dissolved oxygen content and its degree of saturation, temperature, and salinity, respectively are found in the upwelling area.Average of N/P ratio in the area (15.9) approaches to Redfield ratio.Their vertical flux is estimated to be 23.6 mg/ (m²·d) for PQ₄³-P, 223 mg/ (m²·d) for NO₃-N, 302 mg/ (m²·d) for SiO₃^2--Si, respectively, which is the main source of nutients in the areas in summer.The mean of the flux of PO₄^3--P and NO₃^--N is about 86% and 73% necessary for phytoplankton in the euphotic zone.

The diel vertical migration (DVM) of zooplankton and the influence of upwelling on zooplankton biomass were examined using water column data of current velocity and mean volume backscattering strength (MVBS) collected by moored acoustic Doppler current profilers (ADCPs) deployed in the southeastern Chukchi Sea during the 5th Chinese National Arctic Research Expedition (CHINARE) in summer 2012, combined with the satellite observational data such as sea surface temperature (SST), wind, and chlorophyll a (Chl a). Hourly acoustic data were continuously collected for 49-d in the mooring site. Spectral analysis indicated that there were different migrating patterns of zooplankton, even though precisely classifying the zooplankton taxa was not available. The prevailing 24-h cycle corresponded to the normal DVM with zooplankton swimming upwards at sunrise and returning to deep waters at sunset. There was a clear DVM in the upper 17 m of the water column during the period with distinct day-night cycles, and no active DVM throughout the water column when the sun above the horizon (polar day), suggesting that light intensity was the trigger for DVM. Also there was a second migrating pattern with 12-h cycle. The upwelling event occurring in the northwest of Alaskan coastal area had important influence on zooplankton biomass at the mooring site. During the upwelling, the SST close to the mooring site dropped significantly from maximal 6.35℃ to minimal 1.31℃ within five days. Simultaneously, there was a rapid increase in the MVBS and Chl a level, suggesting the aggregation of zooplankton related to upwelling.

A comprehensive study on the phytoplankton standing stocks, species composition and dominant species in the eutrophic Changjiang (Yangtze River) Estuary (CE) was conducted to reveal the response of phytoplankton assemblage to Changjiang Diluted Water (CDW) and upwelling in the spring. Phytoplankton presented peak standing stocks (13.03 μg/L of chlorophyll a, 984.5×10³ cells/L of phytoplankton abundance) along the surface isohaline of 25. Sixty-six species in 41 genera of Bacillariophyta and 33 species in 19 genera of Pyrrophyta were identified, as well as 5 species in Chlorophyta and Chrysophyta. Karenia mikimotoi was the most dominant species, followed by Prorocentrum dentatum, Paralia sulcata, Pseudo-nitzschia delicatissima and Skeletonema costatum. A bloom of K. mikimotoi was observed in the stratified stations, where the water was characterized by low nitrate, low phosphate, low turbidity, and specific ranges of temperature (18-22 °C) and salinity (27-32). K. mikimotoi and P. dentatum accumulated densely in the upper layers along the isohaline of 25. S. costatum was distributed in the west of the isohaline of 20. Benthonic P. sulcata presented high abundance near the bottom, while spread upward at upwelling stations. CDW resulted in overt gradients of salinity, turbidity and nutritional condition, determining the spatial distribution of phytoplankton species. The restricted upwelling resulted in the upward transport of P. sulcata and exclusion of S. costatum, K. mikimotoi and P. dentatum. The results suggested that CDW and upwelling were of importance in regulating the structure and distribution of phytoplankton assemblage in the CE and the East China Sea.

It has been reported that global warming has negative effects on coral ecosystems in the past 50 years and the effects vary in different ocean environment. In order to make clear the coral reef status in the background of global warming along the south coast of Hainan Island of China, satellite and in situ data are used to retrieve the information of the coral reef status and surrounding environmental factors. The results show that cool water induced by upwelling along the south coast of Hainan Island is found in the area every summer month, especially in the relatively strong El Niño years (2002-2003 and 2005). From the NOAA satellite data, degree heating week (DHW) index does not exceed 3 in Sanya Bay even in the relatively strong El Niño years. By comparison of a coral reef growth rate in the Sanya Bay with respect to El Niño events from 1957 to 2000, coral's growth rate is relatively greater during 1972, 1991-1994 and 1998 El Niño event. By analyzing the environmental factors, it is found that the cool water induced by upwelling may be the main reason for protecting corals from global warming effects.

The coastal upwelling has profound influence on the surrounding ecosystem by supplying the nutrient-replete water to the euphotic zone. Nutrient biogeochemistry was investigated in coastal waters of the eastern Hainan Island in summer 2015 and autumn 2016. From perspectives of nutrient dynamics and physical transport, the nutrient fluxes entered the upper 50 m water depth (between the mixed layer and the euphotic zone) arisen from the upwelling were estimated to be 2.5−5.4 mmol/(m²·d), 0.15−0.28 mmol/(m²·d), and 2.2−7.2 mmol/(m²·d) for dissolved inorganic nitrogen (DIN), phosphate (DIP), and dissolved silicate (DSi), respectively, which were around 6- to 12-fold those in the background area. The upwelled nutrients supported an additional plankton growth of (14.70±8.95) mg/m² for chlorophyll a (Chl a). The distributions of nitrate δ¹⁵N and δ¹⁸O above the 300 m water depth (top of the North Pacific Intermediate Water) were different among the upwelling area, background area in summer, and the stations in autumn, and the difference of environmental and biogeochemical conditions between seasons should be the reason. The higher DIN/DIP concentration ratio, nitrate concentration anomaly, and lower nitrate isotope anomaly (Δ(15, 18)) in the upper ocean in summer than in autumn indicated the stronger nitrogen fixation and atmospheric deposition, and the following fixed nitrogen regeneration in summer. The higher values of Chl a and nitrate δ¹⁵N and δ¹⁸O within the euphotic zone in autumn than the background area in summer suggested the stronger nitrate assimilation in autumn. The differences in relatively strength of the assimilation, nitrogen fixation and atmospheric deposition, and the following remineralization and nitrification between the two seasons made the higher δ¹⁸O:δ¹⁵N and larger difference of enzymatic isotope fractionation factors ¹⁵ε and ¹⁸ε for nitrate assimilation in summer than in autumn above the North Pacific Tropical Water.

Phytoplankton productivity and community structure in marginal seas have been altered significantly during the past three decades, but it is still a challenge to distinguish the forcing mechanisms between climate change and anthropogenic activities. High time-resolution biomarker records of two ²¹⁰Pb-dated sediment cores (#34: 28.5°N, 122.272°E; CJ12-1269: 28.861 9°N, 122.515 3°E) from the Min-Zhe coastal mud area were compared to reveal changes of phytoplankton productivity and community structure over the past 100 years. Phytoplankton productivity started to increase gradually from the 1970s and increased rapidly after the late 1990s at Site #34; and it started to increase gradually from the middle 1960s and increased rapidly after the late 1980s at Site CJ12-1269. Productivity of Core CJ12-1269 was higher than that of Core #34. Phytoplankton community structure variations displayed opposite patterns in the two cores. The decreasing D/B (dinosterol/brassicasterol) ratio of Core #34 since the 1960s revealed increased diatom contribution to total productivity. In contrast, the increasing D/B ratio of Core CJ12-1269 since the 1950s indicated increased dinoflagellate contribution to total productivity. Both the productivity increase and the increased dinoflagellate contribution in Core CJ12-1269 since the 1950-1960s were mainly caused by anthropogenic activities, as the location was closer to the Changjiang River Estuary with higher nutrient concentration and decreasing Si/N ratios. However, increased diatom contribution in Core #34 is proposed to be caused by increased coastal upwelling, with higher nutrient concentration and higher Si/N ratios.

The Changjiang River diluted water (CDW) spreads into the East China Sea (ECS) primarily in a plume pattern, although in some years, low-salinity water lenses (LSWLs) detach from the main body of the CDW. In-situ observations indicate that in August 2006, a LSWL detached from the main body of the CDW near the river mouth. In this paper, the effects of winds, tides, baroclinity and upwelling on LSWLs are explored with a three-dimensional model. The results show that: (1) winds play a crucial role in these detachment events because wind-induced northerly Eulerian residual currents impose an uneven force on the CDW and cut it off, thus forming a LSWL; (2) upwelling carries high-salinity water from the lower layer to the upper layer, truncating the low-salinity water tongue vertically, which is conducive to the detachment and maintenance of LSWLs; and (3) upwelling during the evolution of a LSWL is caused by the combined effects of winds and tides. The influences of wind-induced upwelling are mainly near the shore, whereas the upwelling along the 30 m isobath is predominantly affected by tides, with the effect increasing from neap tide to spring tide.

This paper discusses the quantitative variation,ecological groups,community characteristic,vertical distribution and the composition of Ostracoda in different water layers,with the emphasis on the analysis of relation between Ostracoda and water masses,and the impacts from hypersaline upwelling and local density circulations on this group of animal.