Changes in the seasonal cycles of inorganic nutrients in the coastal zone of the southeastern North Sea from 1960 to 1997: effects of eutrophication and sensitivity to meteoclimatic factors

Fock, Heino O.

doi:10.1016/s0025-326x(03)00287-x

Cited by 14 publications

(11 citation statements)

References 88 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The molar N:P ratios for the total fractions of riverine inputs have increased from 10 to 20 during the period 1977-1986 to 15 to 30 from 1992 to 2000. Observations of nutrient concentrations in the coastal waters, for instance at Helgoland Roads (German Bight), have shown that the temporal development of riverine inputs was imposed on the receiving coastal waters (Fock 2003). The strong changes of N:P ratios in the sea over the last decades were attributed to the change of nutrient inputs during that time (Radach et al 1990;Hickel et al 1992;Hickel 1998).…”

Section: Riverine Inputs In Relation To Other Budget Contributions Tomentioning

confidence: 99%

Variability of continental riverine freshwater and nutrient inputs into the North Sea for the years 1977–2000 and its consequences for the assessment of eutrophication

Radach¹,

Pätsch²

2007

Estuaries and Coasts

View full text Add to dashboard Cite

We determined the monthly and annual riverine freshwater, nitrogen (N) and phosphorus (P) loading into the North Sea from Belgium, The Netherlands, and Germany for the years 1977-2000. An average of 133 km 3 yr 21 of the 309 km 3 yr 21 precipitation into the watershed is carried by the rivers into the sea. Total freshwater discharge fluctuates with a strong 6-7 yr periodicity, is strongly correlated with precipitation, and exhibits a slight long-term decrease. The temporal changes of regional patterns of precipitation lead to changing ratios of annual discharge of the western rivers compared to the eastern rivers, varying between 2.2 and 3.5. The long-term oscillations in discharge were more pronounced as discharge increased. The annual means of total and dissolved inorganic N and P loads were estimated to be 722 and 582 kt N yr 21 and 48 and 26 kt P yr 21 , respectively. The monthly N loads were much more strongly correlated with discharge, compared to the monthly P loads. Total N and P as well as dissolved inorganic N also demonstrated a 6-7 yr periodicity. The annual N loads decreased by about 17 kt N yr 21 from 1977 to 2000. The total phosphorus and phosphate loads decreased from about 80 and 50 kt P yr 21 in the 1980s to 25 and 12 kt P yr 21 , respectively, in the 1990s. The western rivers contributed the major part of the nutrient loads. The long-term oscillations in their nutrient loads were much more pronounced, compared to the eastern rivers. The area-specific loading rates estimated for all rivers are comparable to earlier estimates using shorter data records, smaller sample sizes, and a less complete watershed monitoring program. The monthly and annual average N:P ratios and their variability increased considerably for individual rivers during the study interval. These results confirm that the water quality of European continental rivers is strongly influenced by intense land use. They demonstrate the necessity for using long time series monitoring results to assess change and evaluate the effects of climate change on the North Sea coastal ecosystems, using ecosystem models on decadal time scales.

show abstract

Section: Riverine Inputs In Relation To Other Budget Contributions Tomentioning

confidence: 99%

Variability of continental riverine freshwater and nutrient inputs into the North Sea for the years 1977–2000 and its consequences for the assessment of eutrophication

Radach¹,

Pätsch²

2007

Estuaries and Coasts

View full text Add to dashboard Cite

show abstract

“…In several coastal systems, the limitation by N or O varies seasonally (Jennerjahn et al, 2009;Wan et al, 2011). These seasonal cycles mainly depend on the biological processes of production and regeneration due to the decomposition of organic matter; the supply of nutrients and hydrology and hydrodynamics (Fock, 2003), mainly temperature, salinity and concentration of dissolved oxygen (DO). Therefore, it is necessary to consider possible seasonal variations in the behavior of nitrogen and phosphorus, and incorporate these three hydrological variables for an adequate interpretation of the processes that involve nutritional elements in the marine environment.…”

Section: Obtención De Datos Físico-químicosmentioning

confidence: 99%

“…December 2017 los nutrientes y la hidrología e hidrodinámica (Fock, 2003), principalmente temperatura, salinidad y concentración de oxígeno disuelto (OD). Es por esto que, es necesario considerar posibles variaciones estacionales en el comportamiento del nitrógeno y el fósforo, e incorporar estas tres variables hidrológicas para una adecuada interpretación de los procesos que involucran a los elementos nutritivos en el medio marino.…”

Section: Introductionunclassified

Untitled

Monroy

Ghinaglia

Poblete

et al. 2017

rbio

View full text Add to dashboard Cite

“…Temporal changes in nutrients have also been examined in order to determine patterns over time. In general, studies that claim to address temporal scales of nutrients in aquatic systems often do so by examining trends in monthly and/or seasonal sampling, where few samples are taken to represent lengthy periods of time (Fock 2003, Buzzelli et al 2004, Brodie et al 2007). Short-term changes in nutrients can cause confusion when trying to interpret long-term trends in datasets.…”

Section: Sampling Benefits and Recommendationsmentioning

confidence: 99%

Spatial and temporal monitoring of coastal water quality: refining the way we consider, gather, and interpret patterns

Elsdon

Connell²

2009

Aquat. Biol.

View full text Add to dashboard Cite

Environmental scientists are expected to provide interpretations about patterns across broad scales of space and time, but face the challenge that the environment can vary at smaller spatial scales than commonly recognised. We described spatial and temporal variability in nutrients and associated environmental parameters at sites associated with historical impacts to assess appropriate monitoring practices. Sites were selected on the basis of past research into nutrient-driven habitat change. Temporal variability was examined using a nested sampling design (i.e. days within weeks, weeks within months) that included monitoring nutrients and environmental parameters such as secchi depth, chlorophyll a, ammonia, total Kjeldahl nitrogen, total nitrogen (TN), and oxidised nitrogen. Impacted and control sites differed in nutrient concentration and Secchi depth, although sites did not differ on every sampling occasion. Impacted sites always ranked higher, based on means, in nutrient concentrations and were more turbid than control sites. In general, one impacted site had greater nutrient concentration and was more turbid than the other impacted site. Control sites typically had low and stable concentrations of TN. Variation over small time scales of days was large relative to variation at scales of weeks and months; these results warn that monitoring of long-term trends must be mindful of short-term variation and its capacity to confuse interpretations over broader time scales. In this regard, we make suggestions to improve the way we consider, gather, and interpret patterns in environmental data that almost always vary on small scales.

show abstract

Changes in the seasonal cycles of inorganic nutrients in the coastal zone of the southeastern North Sea from 1960 to 1997: effects of eutrophication and sensitivity to meteoclimatic factors

Cited by 14 publications

References 88 publications

Variability of continental riverine freshwater and nutrient inputs into the North Sea for the years 1977–2000 and its consequences for the assessment of eutrophication

Variability of continental riverine freshwater and nutrient inputs into the North Sea for the years 1977–2000 and its consequences for the assessment of eutrophication

Untitled

Spatial and temporal monitoring of coastal water quality: refining the way we consider, gather, and interpret patterns

Contact Info

Product

Resources

About