scholarly journals Influences of Nutrient Sources on the Alternation of Nutrient Limitations and Phytoplankton Community in Jiaozhou Bay, Southern Yellow Sea of China

2020 ◽  
Vol 12 (6) ◽  
pp. 2224
Author(s):  
Jie Shi ◽  
Qian Leng ◽  
Junying Zhu ◽  
Huiwang Gao ◽  
Xinyu Guo ◽  
...  
Keyword(s):  
Atmospheric Deposition ◽  
Phytoplankton Community ◽  
Inorganic Nitrogen ◽  
Marine Ecosystem ◽  
Jiaozhou Bay ◽  
Nutrient Concentrations ◽  
River Input ◽  
Aquaculture Wastewater ◽  
The 1960S ◽  
Yellow Sea Of China

A marine ecosystem box model was developed to reproduce the seasonal variations nutrient concentrations and phytoplankton biomasses in Jiaozhou Bay (JZB) of China. Then, by removing each of the external sources of nutrients (river input, aquaculture, wastewater discharge, and atmospheric deposition) in the model calculation, we quantitatively estimated its influences on nutrient structure and the phytoplankton community. Removing the river input of nutrients enhanced silicate (SIL) limitation to diatoms (DIA) and decreased the ratio of DIA to flagellates (FLA); removing the aquaculture input of nutrients decreased FLA biomass because it provided less dissolved inorganic nitrogen (DIN) but more dissolved inorganic phosphate (DIP) as compared to the Redfield ratio; removing the wastewater input of nutrients changed the DIN concentration dramatically, but had a relatively weaker impact on the phytoplankton community than removing the aquaculture input; removing atmospheric deposition had a negligible influence on the model results. Based on these results, we suppose that the change in the external nutrients sources in the past several decades can explain the long-term variations in nutrient structure and phytoplankton community. Actually, the simulations for the 1960s, 1980s, and 2000s in JZB demonstrated the shift of limiting nutrients from DIP to SIL. A reasonable scenario for this is the decrease in riverine SIL and increase in DIP from aquaculture that has reduced DIA biomass, promoted the growth of FLA, and led to the miniaturization of the phytoplankton.

scholarly journals Nutrient Atmospheric Deposition on Utah Lake: A Comparison of Sampling and Analytical Methods

Hydrology ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 123
Author(s):  
Seth Michael Barrus ◽  
Gustavious Paul Williams ◽  
A. Woodruff Miller ◽  
M. Brett Borup ◽  
LaVere B. Merritt ◽  
...  
Keyword(s):  
Atmospheric Deposition ◽  
Nutrient Loading ◽  
Inorganic Nitrogen ◽  
Dissolve Inorganic Nitrogen ◽  
Nutrient Concentrations ◽  
Nutrient Loads ◽  
Total Load ◽  
Significant Difference ◽  
Utah Lake ◽  
Collection Methods

We describe modified sampling and analysis methods to quantify nutrient atmospheric deposition (AD) and estimate Utah Lake nutrient loading. We address criticisms of previous published collection methods, specifically collection table height, screened buckets, and assumptions of AD spatial patterns. We generally follow National Atmospheric Deposition Program (NADP) recommendations but deviate to measure lake AD, which includes deposition from both local and long-range sources. The NADP guidelines are designed to eliminate local contributions to the extent possible, while lake AD loads should include local contributions. We collected side-by-side data with tables at 1 m (previous results) and 2 m (NADP guidelines) above the ground at two separate locations. We found no statistically significant difference between data collected at the different heights. Previous published work assumed AD rates would decrease rapidly from the shore. We collected data from the lake interior and show that AD rates do not significantly decline away from the shore. This demonstrates that AD loads should be estimated by using the available data and geostatistical methods even if all data are from shoreline stations. We evaluated screening collection buckets. Standard unscreened AD samples had up to 3-fold higher nutrient concentrations than screened AD collections. It is not clear which samples best represent lake AD rates, but we recommend the use of screens and placed screens on all sample buckets for the majority of the 2020 data to exclude insects and other larger objects such as leaves. We updated AD load estimates for Utah Lake. Previous published estimates computed total AD loads of 350 and 153 tons of total phosphorous (TP) and 460 and 505 tons of dissolve inorganic nitrogen (DIN) for 2017 and 2018, respectively. Using updated collection methods, we estimated 262 and 133 tons of TP and 1052 and 482 tons of DIN for 2019 and 2020, respectively. The 2020 results used screened samplers with lower AD rates, which resulted in significantly lower totals than 2019. We present these modified methods and use data and analysis to support the updated methods and assumptions to help guide other studies of nutrient AD on lakes and reservoirs. We show that AD nutrient loads can be a significant amount of the total load and should be included in load studies.

scholarly journals Human-Driven Atmospheric Deposition of N and P Controls on the East Mediterranean Marine Ecosystem

2016 ◽  
Vol 73 (4) ◽  
pp. 1611-1619 ◽  
Author(s):  
S. Christodoulaki ◽  
G. Petihakis ◽  
N. Mihalopoulos ◽  
K. Tsiaras ◽  
G. Triantafyllou ◽  
...  
Keyword(s):  
Atmospheric Deposition ◽  
Mediterranean Sea ◽  
Inorganic Nitrogen ◽  
Marine Ecosystem ◽  
N:P Ratio ◽  
Biogeochemical Model ◽  
East Mediterranean ◽  
Set Up ◽  
Representative Area ◽  
The Impact

Abstract The historical and future impacts of atmospheric deposition of inorganic nitrogen (N) and phosphorus (P) on the marine ecosystem in the east Mediterranean Sea are investigated by using a 1D coupled physical– biogeochemical model, set up for the Cretan Sea as a representative area of the basin. For the present-day simulation (2010), the model is forced by observations of atmospheric deposition fluxes at Crete, while for the hindcast (1860) and forecast (2030) simulations, the changes in atmospheric deposition calculated by global chemistry–transport models are applied to the present-day observed fluxes. The impact of the atmospheric deposition on the fluxes of carbon in the food chain is calculated together with the contribution of human activities to these impacts. The results show that total phytoplanktonic biomass increased by 16% over the past 1.5 centuries. Small fractional changes in carbon fluxes and planktonic biomasses are predicted for the near future. Simulations show that atmospheric deposition of N and P may be the main mechanism responsible for the anomalous N:P ratio observed in the Mediterranean Sea.

NUTRIENT DECREASE IN THE SETO INLAND SEA, JAPAN, AND THE RESPONSE OF THE PHYTOPLANKTON ASSEMBLAGE TO THE DECREASE

2017 ◽  
Author(s):  
Kuninao Tada ◽  
Kuninao Tada ◽  
Kazuhiko Ichimi ◽  
Kazuhiko Ichimi ◽  
Miho Kayama ◽  
...  
Keyword(s):  
Inorganic Nitrogen ◽  
Species Group ◽  
Trophic Levels ◽  
Seto Inland Sea ◽  
Nutrient Concentrations ◽  
Overlying Water ◽  
Phytoplankton Assemblages ◽  
The Seto Inland Sea ◽  
Apparent Decrease ◽  
The 1960S

The nutrient decrease in the eastern part of the Seto Inland Sea and its influence on the lower trophic levels of the coastal ecosystem are discussed based on the information obtained during our previous study. During the high economic growth from the 1960s onwards, the Seto Inland Sea became heavily eutrophicated. Since the enactment of the Law for Conservation of the Environment of the Seto Inland Sea in 1973, nutrient concentrations gradually decreased after 1970 and dissolved inorganic nitrogen (DIN) concentration in particular decreased after 1990. One fundamental explanation for the gradual decrease of DIN concentration from 1970 to the present is the enactment of the above law by the Environmental Agency. However, the reason for the recent decrease of DIN concentrations is still unknown. It was thought that the decrease of the upward nutrient flux across the overlying water-sediment interface greatly affected the water column nutrient concentrations. The response of phytoplankton assemblages to the decrease of nutrient concentrations seemed to be no apparent decrease of biomass but a change of species group and species composition.

NUTRIENT DECREASE IN THE SETO INLAND SEA, JAPAN, AND THE RESPONSE OF THE PHYTOPLANKTON ASSEMBLAGE TO THE DECREASE

2017 ◽  
Author(s):  
Kuninao Tada ◽  
Kuninao Tada ◽  
Kazuhiko Ichimi ◽  
Kazuhiko Ichimi ◽  
Miho Kayama ◽  
...  
Keyword(s):  
Inorganic Nitrogen ◽  
Species Group ◽  
Trophic Levels ◽  
Seto Inland Sea ◽  
Nutrient Concentrations ◽  
Overlying Water ◽  
Phytoplankton Assemblages ◽  
The Seto Inland Sea ◽  
Apparent Decrease ◽  
The 1960S

The nutrient decrease in the eastern part of the Seto Inland Sea and its influence on the lower trophic levels of the coastal ecosystem are discussed based on the information obtained during our previous study. During the high economic growth from the 1960s onwards, the Seto Inland Sea became heavily eutrophicated. Since the enactment of the Law for Conservation of the Environment of the Seto Inland Sea in 1973, nutrient concentrations gradually decreased after 1970 and dissolved inorganic nitrogen (DIN) concentration in particular decreased after 1990. One fundamental explanation for the gradual decrease of DIN concentration from 1970 to the present is the enactment of the above law by the Environmental Agency. However, the reason for the recent decrease of DIN concentrations is still unknown. It was thought that the decrease of the upward nutrient flux across the overlying water-sediment interface greatly affected the water column nutrient concentrations. The response of phytoplankton assemblages to the decrease of nutrient concentrations seemed to be no apparent decrease of biomass but a change of species group and species composition.

Modelling nitrogen transport across compartments over northern Europe

2021 ◽  
Author(s):  
Stefan Hagemann ◽  
Ute Daewel ◽  
Volker Matthias ◽  
Tobias Stacke
Keyword(s):  
Baltic Sea ◽  
Land Surface ◽  
Climate Model ◽  
Transport Model ◽  
Atmospheric Transport ◽  
Regional Climate ◽  
Marine Ecosystem ◽  
Coupled System ◽  
Nutrient Concentrations ◽  
Nutrient Loads

<p>River discharge and the associated nutrient loads are important factors that influence the functioning of the marine ecosystem. Lateral inflows from land carrying fresh, nutrient-rich water determine coastal physical conditions and nutrient concentration and, hence, dominantly influence primary production in the system. Since this forms the basis of the trophic food web, riverine nutrient concentrations impact the variability of the whole coastal ecosystem. This process becomes even more relevant in systems like the Baltic Sea, which is almost decoupled from the open ocean and land-borne nutrients play a major role for ecosystem productivity on seasonal up to decadal time scales.</p><p> </p><p>In order to represent the effects of climate or land use change on nutrient availability, a coupled system approach is required to simulate the transport of nutrients across Earth system compartments. This comprises their transport within the atmosphere, the deposition and human application at the surface, the lateral transport over the land surface into the ocean and their dynamics and transformation in the marine ecosystem. In our study, we combine these processes in a modelling chain within the GCOAST (Geesthacht Coupled cOAstal model SysTem) framework for the northern European region. This modelling chain comprises:</p><p> </p><ul><li>Simulation of emissions, atmospheric transport and deposition with the chemistry transport model CMAQ at 36 km grid resolution using atmospheric forcing from the coastDat3 data that have been generated with the regional climate model COSMO-CLM over Europe at 0.11° resolution using ERA-Interim re-analyses as boundary conditions</li> <li>Simulation of inert processes at the land surface with the global hydrology model HydroPy (former MPI-HM), i.e. considering total nitrogen without any chemical reactions</li> <li>Riverine transport with the Hydrological Discharge (HD) model at 0.0833° spatial resolution</li> <li>Simulation of the North Sea and Baltic Sea ecosystems with 3D coupled physical-biogeochemical NPZD-model ECOSMO II at about 10 km resolution</li> </ul><p> </p><p>We will present first results and their validation from this exercise.</p><p> </p>

A statistical dynamics model of the marine ecosystem and its application in Jiaozhou Bay

2011 ◽  
Vol 29 (4) ◽  
pp. 905-911 ◽  
Author(s):  
Honghua Shi ◽  
Zongling Wang ◽  
Guohong Fang ◽  
Wei Zheng ◽  
Long Hu
Keyword(s):  
Marine Ecosystem ◽  
Jiaozhou Bay ◽  
Dynamics Model ◽  
Statistical Dynamics

Nutrient pollution at the lower reaches of Mediterranean coastal rivers in Israel

2000 ◽  
Vol 42 (1-2) ◽  
pp. 147-152 ◽  
Author(s):  
B. Herut ◽  
N. Kress ◽  
H. Hornung
Keyword(s):  
Inorganic Nitrogen ◽  
Agricultural Runoff ◽  
Point Sources ◽  
Industrial Wastes ◽  
Nutrient Concentrations ◽  
Contamination Level ◽  
Nutrient Load ◽  
Nutrient Loads ◽  
Discharge Data ◽  
Coastal Rivers

This study represents the first attempt to evaluate the nutrient load introduced into the coastal waters by the rivers along the Mediterranean coast of Israel. Measurements of nutrient concentrations (phosphate, ammonium, nitrate, nitrite, silicic acid) at two or three stations along the lower river reaches (11 rivers) were carried out annually from 1990 up to 1998. Combining the nutrient concentrations with the monthly riverine discharges we assessed the nutrient load. In general, most of the coastal rivers contain high nutrient contamination level, compared to the criteria adopted by NOAA (USA) for coastal river estuaries. The high degree of contamination is attributed to extreme low natural flow combined with the discharge of domestic and industrial wastes, and with agriculture runoff. In terms of nutrient concentrations, the Kishon River is the most polluted, followed by the Soreq, Poleg and Alexander Rivers. The preliminary estimate is that the coastal rivers transport between ~2000 to 6000 tons of dissolved inorganic nitrogen (DIN) and between ~250–800 tons of dissolved inorganic phosphorus (DIP) to the sea. An additional 3500 and 3000 tons of DIN and DIP, respectively, are supplied through the Kishon River. The load of the Poleg River is unknown (no discharge data) but expected to be significant based on nutrient concentration measured. The total load of the coastal rivers constitutes a major component among the other land-base point sources such as the Gush Dan outfall. Our estimate probably represents minimal values, as it does not include diffused input of agricultural runoff nor the riverine particulate and dissolved organic nutrient loads (which are unknown).

Sign in / Sign up

Export Citation Format

Share Document