katarzyna matuszewska
DESCRIPTION
University of Gdansk, Institute of Oceanography Department of Marine Chemistry and Marine Environment Protection. THE IMPACT OF THE BOTTOM TRAWLING ON NUTRIENTS EXCHANGE BETWEEN SEDIMENT AND OVERLYING WATER IN THE GULF OF GDANSK. Katarzyna Matuszewska - PowerPoint PPT PresentationTRANSCRIPT
THE IMPACT OF THE BOTTOM TRAWLING THE IMPACT OF THE BOTTOM TRAWLING ON NUTRIENTS EXCHANGE BETWEEN ON NUTRIENTS EXCHANGE BETWEEN
SEDIMENT AND OVERLYING WATER IN SEDIMENT AND OVERLYING WATER IN THE THE GULF OF GDANSKGULF OF GDANSK
Katarzyna Matuszewska
Dorota Burska, Bożena Graca, Dorota Pryputniewicz, Izabela Białkowska Jerzy Bolałek
Costing the impact of demersal fishing on marine ecosystem processes and biodiversity Q5RS-2001-00993)
ELOISE, Portorož, November 14-18, 2004
University of Gdansk, Institute of OceanographyUniversity of Gdansk, Institute of Oceanography
Department of Marine Chemistry and Marine Environment ProtectionDepartment of Marine Chemistry and Marine Environment Protection
Gulf of Gdansk
a eutrophic, first-order estuary of the Vistula (one of the largest rivers discharging into the Baltic Sea)
salinity : 7 to 8 PSU (uniform to a depth of 60-70 m)
A halocline occurs below the depth of 70 m, separating the upper isohaline water from more saline (10-13PSU) bottom water usually suffering from oxygen deficit
seasonal thermal stratification
65% of the bottom is covered by muddy – silty sediments; at the rest of the bottom sandy sediments occur (Szczepańska T., Uścinowicz Sz., 1994; Witek et al., 2003)
18.75 ° 19 ° 19.25 ° 19.5 °
54.3 °
54.5 °
54.7 °
5 Nm
Baltic Sea
10m
20m
30m
60m
80m
Sampling area
Baltic field experiments:19 - 28.03.2003,
23.06 – 2.07.2003
- Fairaway area (untrawled)
Site 1
Site 2
Site 3
Site 4
- trawled stations
UD1
UD2
UD3
UD4
- control stations
UN1
UN2
UN3
UN4
Vistula river
Site- corresponding pair of control and trawled station
Environmental parameters measurements:
Sediment: Corg, Ntot (Hedges and Stern, 1984), P forms (Jensen and Thamdrup,1993), chlorphyll a (Edler, 1979, Parsons et al., 1985), grain size, humidity (drying to the constant mass at 105oC), LOI (ignition at 450oC)
Near-bottom water : salinity, temperature, oxygen, biogenic substances (Grasshoff et al. 1983)
Pore water: biogenic substances (Grasshoff et al. 1983)
The sediment-water nutrient fluxes were calculated from the equation:
NF = (C - C0)*F*103 / A*Mw where
NF is the nutrient flux (µmol m-2 h-1)C is the concentration of nutrient in the water entering the core (mg kg-1)C0 is the concentration of nutrient in the water leaving the core (mg kg-1)F is the flow of water through the core (kg h-1)A is the area of the core (m2)Mw is the molecular weight of nutrient ion
The
Vis
tula
Hel Peninsula
UN1,UD1UN2, UD2
UN3UD3
UN4UD4
0 20 40 60 80 100
Corg
Ntot
0 20 40 60 80 100
Porg
Chl-a
0 20 40 60 80 100
LOI
H
sandy silt
mg g-1 d.s.
g g-1 d.s.
%
silty sand
mg g-1 d.s.
g g-1 d.s.
%
0 20 40 60 80 100
Corg
Ntot
silt
g g-1 d.s.
mg g-1 d.s.
%
0 20 40 60 80 100
Corg
Ntot
0 20 40 60 80 100
Porg
Chl-a
0 20 40 60 80 100
LOI
H
0 20 40 60 80 100
Porg
Chl-a
0 20 40 60 80 100
LOI
H
The
Vis
tula
Hel Peninsula
UN1,UD1UN2, UD2
UN3UD3
UN4UD4
Phosphate [mol dm-3]
-20
-15
-10
-5
0
0 50 100 150 200 250 300 350
de
pth
[c
m]
mean
Phosphate [mol dm-3]
-20
-15
-10
-5
0
0 50 100 150 200 250 300 350
de
pth
[c
m]
mean
Phosphate [mol dm-3]
-20
-15
-10
-5
0
0 50 100 150 200 250 300 350
de
pth
[c
m]
mean
The
Vis
tula
Hel Peninsula
UN1,UD1UN2, UD2
UN3UD3
UN4UD4
Ammonium [mol dm-3]
-20
-15
-10
-5
0
0 400 800 1200 1600 2000 2400
de
pth
[c
m]
mean
Ammonium [mol dm-3]
-20
-15
-10
-5
0
0 400 800 1200 1600 2000 2400
de
pth
[c
m]
mean
Ammonium [mol dm-3]
-20
-15
-10
-5
0
0 400 800 1200 1600 2000 2400
de
pth
[c
m]
mean
The
Vis
tula
Hel Peninsula
UN1,UD1UN2, UD2
UN3UD3
UN4UD4
Silicate [mol dm-3]
-20
-15
-10
-5
0
0 250 500 750 1000
de
pth
[c
m]
mean
Silicate [mol dm-3]
-20
-15
-10
-5
0
0 250 500 750 1000
de
pth
[c
m]
mean
Silicate [mol dm-3]
-20
-15
-10
-5
0
0 250 500 750 1000
de
pth
[c
m]
mean
-20
-15
-10
-5
0
0 50 100 150 200 250 300
phosphate [mol dm-3]d
epth
[cm
]
trawled control
-20-15-10
-50
0 300 600 900silicate [mol dm-3]
de
pth
[c
m]
trawled control
-20
-15
-10
-5
0
0 100 200 300 400 500
ammonium [mol dm-3]
dep
th [
cm]
trawled control
Ammonium flux
[microM m-2 h-1]
-350-300-250-200-150-100-50
050
100
trawled control
Phosphate flux [microM
m-2 h-1]
-250
-150
-50
50
150
trawled control
Silicate flux [microM m-2
h-1]
-700-600-500-400-300-200-100
0
trawled control
Oxygen consumption
[microM m-2 h-1]
0500
100015002000250030003500
trawled control
The U-Mann Whitney’s test and Principal Component Analysis (PCA) were used to test the hypothesis:
Trawling impacts in a significant way the exchange of nutrients and oxygen at the water-sediment interface.
NIT
RIT
E [
mic
roM
m-2
h-1
]
-12
-8
-4
0
4
TRAWLED CONTROL
OX
YG
EN
[m
icro
M m
-2h
-1]
1000
2000
3000
4000
TRAWLED CONTROL
SIL
ICA
TE
[m
icro
M m
-2h
-1]
-900
-600
-300
0
TRAWLED CONTROL
Min-Maks.25%-75%Mediana
The differences in the fluxes between the hole set of control and traweled stations (regardless of geographic position and season) were significant (p<0.05) for silicates, oxygen and nitrites.
Principal component analysis
Component I Component II Component III
fluxes NH4
+ 0.43 -0.35 -0.71
NO2- -0.58 0.51 -0.36
NO3- -0.15 0.89 0.02
oxygen -0.23 0.08 0.70
PO43- 0.85 0.22 -0.19
SiO44- 0.78 0.17 -0.30
bottom waters oxygen
0.25 -0.86 -0.10
salinity 0.18 0.89 0.14
temperature -0.80 0.24 0.02
sediments organic carbon
0.08
0.09
0.86
interstitial waters PO4
3--0.03 -0.02
0.72
NO3- + NO2
- 0.14 0.42 0.07
Content (%) 31 21 17
principal component I (season)
pri
nci
pal
com
pon
ent
II (
regi
on)
-2,0
-1,5
-1,0
-0,5
0,0
0,5
1,0
1,5
2,0
2,5
-2,5 -2,0 -1,5 -1,0 -0,5 0,0 0,5 1,0 1,5 2,0
JuneMarch
Principal component analysis
17 21 31Content (%)
0.07 0.42 0.14 NO3- + NO2
-
0.72-0.02-0.03
interstitial waters PO4
3-
0.86
0.09
0.08
sediments organic carbon
0.02 0.24-0.80 temperature
0.14 0.89 0.18 salinity
-0.10-0.86
0.25bottom waters oxygen
-0.30 0.17 0.78 SiO44-
-0.19 0.22 0.85 PO43-
0.70 0.08-0.23 oxygen
0.02 0.89-0.15 NO3-
-0.36 0.51-0.58 NO2-
-0.71-0.35 0.43
fluxes NH4
+
Component IIIComponent IIComponent I
principal component I (season)
pri
nci
pal
com
pon
ent
II (
regi
on)
-2,0
-1,5
-1,0
-0,5
0,0
0,5
1,0
1,5
2,0
2,5
-2,5 -2,0 -1,5 -1,0 -0,5 0,0 0,5 1,0 1,5 2,0
U1, U2
TRAWLED AND CONTROL
U3, U4
TRAWLED AND CONTROL
Principal component analysis
17 21 31Content (%)
0.07 0.42 0.14 NO3- + NO2
-
0.72-0.02-0.03
interstitial waters PO4
3-
0.86
0.09
0.08
sediments organic carbon
0.02 0.24-0.80 temperature
0.14 0.89 0.18 salinity
-0.10-0.86
0.25bottom waters oxygen
-0.30 0.17 0.78 SiO44-
-0.19 0.22 0.85 PO43-
0.70 0.08-0.23 oxygen
0.02 0.89-0.15 NO3-
-0.36 0.51-0.58 NO2-
-0.71-0.35 0.43
fluxes NH4
+
Component IIIComponent IIComponent I
principal component II (region)
pri
nci
pal
com
pon
ent
III
(ch
emic
al c
omp
osit
ion
)
-2,5
-2,0
-1,5
-1,0
-0,5
0,0
0,5
1,0
1,5
2,0
-2,0 -1,5 -1,0 -0,5 0,0 0,5 1,0 1,5 2,0 2,5
U1, U2 U4
U3
Corg= 40 mg g-1
(33-57 mg g-1)
Corg= 61 mg g-1
(53-73 mg g-1)
Corg= 16 mg g-1
(10-27 mg g-1)
Principal component analysis
17 21 31Content (%)
0.07 0.42 0.14 NO3- + NO2
-
0.72-0.02-0.03
interstitial waters PO4
3-
0.86
0.09
0.08
sediments organic carbon
0.02 0.24-0.80 temperature
0.14 0.89 0.18 salinity
-0.10-0.86
0.25bottom waters oxygen
-0.30 0.17 0.78 SiO44-
-0.19 0.22 0.85 PO43-
0.70 0.08-0.23 oxygen
0.02 0.89-0.15 NO3-
-0.36 0.51-0.58 NO2-
-0.71-0.35 0.43
fluxes NH4
+
Component IIIComponent IIComponent I
NH4+ NO2
- NO3- oxygen PO4
3- SiO44-
March U1, U2 T -78.60 -5.78 -44.58 2985.21 -4.96 -229.80
C -43.01 -1.54 -37.95 2744.47 -1.06 -210.84
U3 T -23.73 0.60 39.72 2479.65 5.01 -110.48
C -25.18 -0.15 41.60 2551.87 4.84 -107.90
U4 T -198.60 -0.15 75.42 2840.76 1.70 -122.48
C -297.59 0.32 74.78 2937.06 -5.40 -258.85
June U1, U2 T -101.1 0.77 9.50 2327.18 -41.51 -248.97
C -161.97 0.91 9.50 2904.96 -103.39 -619.62
U3 T -31.30 0.12 5.49 1845.69 -8.88 -380.61
C -41.30 0.45 6.83 2423.48 -7.87 -538.95
U4 T -229.48 0.09 6.62 2953.11 -71.31 -463.90
C -283.85 0.23 6.48 3009.28 -57.37 -609.69
All data
T -74.76 0.00 6.46 2551.87 -6.55 -229.80
C -106.80 0.16 9.50 2872.86 -8.01 -387.96
U-Mann Whitney’s Test p<0.05
-20
-15
-10
-5
0
0 50 100 150 200 250 300
phosphate [mol dm-3]d
epth
[cm
]
trawled control
-20-15-10
-50
0 300 600 900silicate [mol dm-3]
de
pth
[c
m]
trawled control
-20
-15
-10
-5
0
0 100 200 300 400 500
ammonium [mol dm-3]
dep
th [
cm]
trawled control
Conclusion
In the majority of cases, trawling resulted in decreased oxygen consumption and the fluxes of ammonia, phosphate and silicate from the sediment. This might be a combined result of a short-term intensive release of nutrients from the sediment immediately after trawling, and a long-term effect caused by better oxygen conditions inside the sediment. The changes on benthic ecosystem caused by trawling depend on many factors such as marine sediment characteristics, intensity and area of trawling and period of the year.
THANK YOU
NH4+ NO2
- NO3- oxygen PO4
3- SiO44-
March U1, U2 T -74.80 -5.78 -44.58 2985.21 -4.96 -229.80
C 3.93 -1.54 -37.95 2744.47 -1.06 -210.84
U3 T -23.73 0.60 39.72 2479.65 5.01 -112.48
C -25.18 -0.15 41.60 2551.87 4.84 -90.90
U4 T -198.60 -0.15 75.42 2840.76 1.70 -122.48
C 297.59 0.32 74.78 2937.06 -5.40 -258.85
June U1, U2 T -172.45 0.77 9.50 2327.18 -41.51 -248.97
C -161.97 0.91 9.50 2904.96 -103.39 -619.62
U3 T -41.30 0.12 -0.15 1845.69 -8.88 -380.61
C -41.30 0.45 6.53 2423.48 -7.87 -538.95
U4 T -293.48 -0.09 6.62 2953.11 -71.31 -463.90
C -263.85 0.23 6.48 3009.28 -57.37 -609.69
All data
T -74.76 0.00 6.46 2551.87 -6.55 -229.80
C -106.80 0.16 9.50 2872.86 -8.01 -387.96
U-Man Whitney’s Test p<0.05
52,68%
29,38%
23,91%
59,85%
3,28%
19,89%
23,84%
DECREASE
40,77%11,17%
UN1 UN2
UN4
UN3
UD4
UD3
UD2UD1
7,82
7,52
7,37
7,48
5,06
4,80
5,13
5,31
9,75
9,75
9,95
10,04
5.15
5,07
2,48
2,50
O2
[cm3 dm-3]
7,17
7,21
7,17
7,27
9,35
9,39
10,22
9,95
8,10
8,33
9,00
8,05
3,62
3,69
3,74
3,73
65
65
66
65
62
62
76
75
UN1
UD1
UN2
UD2
UN3
UD3
UN4
UD4
65
65
66
65
62
62
76
75
h
[m]
7,24
7,25
7,23
7,23
9,98
10,10
11,19
11,13
2,25
2,37
2,18
2,25
6,34
6,44
6,88
6,71
UN1
UD1
UN2
UD2
UN3
UD3
UN4
UD4
S [PSU]T
[Co]
stationdateS
pri
ng
24.0
3
21.
03
Su
mm
er01
.07
2
3.06
Temperature, salinity and oxygen concentration in near-bottom water
Location of sampling stations
( trawled and control)
stoper przeciwdziałający zanieczyszczeniu z powietrza
pomiar temperatury oraz tlenu
plastikowa pokrywa
mały magnetyczny walec 1-2 cm nad osadem
nylonowa nić
Pompa perystaltycznaWatson Marlow
marprenowy wąż o średnicy 1,15 mm (Watson-Marlow)
cienki wąż transferowy z tygonu o średnicy 2 mm
TANK300 l wody nadddennej z rejonu badań
7,6 cm PC-rdzeń z osadem (h = ~29 cm) i wodą (h =~20 cm)
kabel do urządzenia sterującego
schemat systemu przepływowego
założenia ekspetrymentu
•nienaruszone rdzenie•rdzenie o zbliżonej wysokości słupa wody, •stała temperatura w inkubowanych rdzeniach oraz tanku,•stały przepływ ~ 1ml/min •mieszanie nad osadem, •ustalenie stanu równowagi,
codziennie, o stałej porze, w każdym rdzeniu oraz w tanku następuje:•pomiar przepływu,•pomiar temperatury i stężenia tlenu,•pobieranie 150 ml wody do analizy substancji biogenicznych,
przebieg ekspetrymentu