The simplistic nitrogen input and output balance in Lake Łebsko – case study Cover

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The simplistic nitrogen input and output balance in Lake Łebsko – case study

Oceanological and Hydrobiological Studies

Volume 45 (2016): Issue 3 (September 2016)

By: Roman Cieśliński

Open Access

|Sep 2016

Figures & Tables

Location of Lake Łebsko in the Polish coastal zone and location of measurement sites

Discharge in the Łeba Canal between June 2008 and October 2010. Negative values indicate the sea-lake flow direction, while positive values indicate the lake-sea flow.

Inflow of surface water into Lake Łebsko

Mean concentrations of ammonium in Lake Łebsko at selected sampling sites

Changes in the concentration of total nitrogen in Lake Łebsko – two sampling sites. Two sampling sites: Site No. 4 -located in the southern part of the lake; Site No. 8 – located in the northern part of the lake

Changes in the concentration of nitrates in Lake Łebsko. Two sampling sites: Site No. 4 – located in the southern part of the lake; Site No. 8 – located in the northern part of the lake

Total nitrogen load supplied to Lake Łebsko by rivers and canals in 2008-2010

Percentage contribution of selected sources of the total nitrogen load supplied to Lake Łebsko in 2009

Monthly inputs and outputs of total nitrogen [tons month-1] in Lake Łebsko in 2008-2010

Monthly size of Nret and ΔN in Lake Łebsko in 2008-2010

Hypothetical migration of nutrient material into Lake Łebsko from its drainage basin (kg km2 yr-1) based on research by Kajak (1983)

Type of use	Nitrogen
Forests	258.2
Arable land	2295.4
Meadows and pastures	4032.8
Total	6586.4

Concentrations of nutrient substances in Lake Łebsko in the study period

Indicator [unit]	Minimum	Maximum	Average
Total nitrogen [mg N dm^-3]	0.31	3.08	1.25
Nitrates [mg NO₃^- dm^-3]	0.05	1.94	0.58
Ammonium [mg NH₄⁺ dm^-3]	0.90	3.90	2.20

Mean monthly total nitrogen load, nitrate load and ammonium loads (tons per month) for watercourses flowing into Lake Łebsko in 2008-2010

Name	2008	2009	2010
total nitrogen load
Łeba	44.27	35.39	53.55
Pustynka	8.18	9.81	12.64
Other courses	7.27	4.84	6.03
nitrate load
Łeba	35.41	29.64	36.77
Pustynka	6.36	7.82	7.59
Other courses	4.69	2.65	3.16
ammonium loads
Łeba	64.84	51.19	62.43
Pustynka	7.91	7.27	9.18
Other courses	8.83	4.81	6.65

Mean concentrations of nutrient substances in lake surface water, lake bottom water, and lake interstitial water for Lake Łebsko from June 2008 to October 2010

Indicator [unit]	Layer	Point
Indicator [unit]	Layer	1	2	5	6	8	3	4	7
Total nitrogen [mg N dm^-3]	Surface	1.36	1.11	1.21	1.34	1.12	1.33	1.39	1.33
	Near-bottom	1.34	1.16	1.28	1.40	1.16	1.39	1.41	1.41
	Interstitial	1.77	1.64	1.49	2.13	1.67	1.95	1.76	1.62
Nitrates [mg NO₃^- dm^-3]	Surface	0.67	0.53	0.67	0.69	0.50	0.85	0.68	0.56
	Near-bottom	0.67	0.54	0.71	0.64	0.59	0.79	0.79	0.65
	Interstitial	0.79	0.72	0.77	0.86	0.74	0.96	0.78	0.80
Ammonium [mg NH₄⁺ dm^-3]	Surface	2.0	1.8	3.0	1.5	1.3	3.4	3.6	1.6
	Near-bottom	2.1	1.8	3.2	1.6	1.5	3.5	3.6	1.7
	Interstitial	2.2	1.9	3.3	1.9	1.6	3.8	3.8	1.9

Mean loads of nitrogen compounds (tons per month) entering and leaving Lake Łebsko

Ion	Inflow from the catchment	Outflow from the lake	Odds	% amount of load remaining in the lake	Inflow from the sea
N_total	60.03	41.16	18.87	31.43	36.01
N-NO₃	44.20	16.50	27.70	62.50	30.16
N-NH₄	72.86	67.02	5.84	8.02	82.56

Size of total nitrogen loads discharged into Lake Łebsko in 2009 via various routes

Name	Annual load in tons
Łeba	424.72
Pustynka	117.70
Other courses	58.07
Runoff	47.00
Baltic Sea	87.81
Precipitation	104.30
Total	839.60
Outflow to the sea	304.65

Mean concentrations of nutrient substances in river and stream water reaching Lake Łebsko between June 2008 and October 2010

Name	Total nitrogen[mg N dm^-3]	Nitrates[mg NO₃^- dm^-3]	Ammonium[mg NH₄⁺ dm^-3]
Gardno – Łebsko Canal	1.44	0.69	2.48
Łupawa – Łebsko Canal	2.04	0.89	2.66
Łeba	1.85	1.41	2.25
Old Łeba	1.92	1.02	2.28
Pustynka	2.37	1.64	2.95
Canal Żarnowski	3.20	1.29	3.16
Canal Żelazo	1.64	1.18	2.67
Canal Witkowo	1.85	1.05	2.44
Canal Izbicki	1.97	1.03	3.15
Lake Łebsko	1.27	0.64	2.20

DOI: https://doi.org/10.1515/ohs-2016-0037 | Journal eISSN: 1897-3191 | Journal ISSN: 1730-413X

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Language: English

Page range: 424 - 443

Submitted on: Oct 7, 2015

Accepted on: Jan 11, 2016

Published on: Sep 22, 2016

Published by: University of Gdańsk

In partnership with: Paradigm Publishing Services

Publication frequency: 4 issues per year

Keywords:

hydrochemistry,

Related subjects:

Chemistry, other,

Geosciences, other,

Life sciences, other

© 2016 Roman Cieśliński, published by University of Gdańsk
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

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