Post on 03-Aug-2018
Human impacts in catchments and lakes of the Antarctic oases
Schirmacher , Thala and Larsemann
Enn Kaup Institute of Geology at Tallinn University of
Technology, Estonia
Review of research during 1976-1998at Novolazarevskaya, Molodezhnaya,
Progress, Zhong Shan, Law Base
Transfer of human impacts to antarctic lakes and their catchments
● Long-range pollutant transfer by global oceanic and atmospheric circulation. Decrease of ozone layer.
● Local impacts through construction and running scientific stations and field camps
● Connected recreation activity of stations' staff and recreation activity of visiting tourists
● Direct research activity of scientists, limnologists included
Direct impacts of scientific stations
● Modification (leveling, crushing, using as building material) of surface by construction of facilities and road networks and operating transport. Including the use of tracked, wheeled vehicles and trampling by pedestrians. Damaging of catchment vegetation has been common.
● This can change hydrological patterns (direction of flow, quantity and quality of flowing waters). An example is increasing of fine sediment (e.g.silt) in the flowing water as a result of rock crushing.
●
Direct impacts of scientific stations
● Spilling of various construction and exploitation materials and wastes onto the catchments and directly into the lakes. Examples are:
● Cement, metal and wood particles, paints, fuels, lubricants & other liquids
● Solid and liquid domestic wastes● Emissions of various engines (power stations,
vehicles) and waste incinerators
A tracked vehicle was driven into L. Stancionnoye without a reason and had to
be rescued by another one
During 1961-76 were station's wastes (food, faeces, oils, H
2-production tails, etc.) stored
on the ice cover of Lake Glubokoye
Loads of nutrients (mmol m-3 of lake) into the lakes during summer flow periods of 1976/77 and
1983/84. Pt - total phosphorus, DRP - dissolved
reactive phosporus, Ninorg
- inorganic nitrogen.
Lake, period Pt DRP Ninorg
Glubokoye 76-77 - 0.740 7.130Glubokoye 83/84 0.074 0.027 1.322Pomornik 83/84 0.530 0.110 4.703Verkhneye 83/84 0.010 0.006 0.348
In 14 years mixing of most of water column was replaced by anaerobic mesothermy
Depth(m)Date
15 May 62 30 Jan 62 28 Aug 76 19 Jan 77
temp temp temp/O2 temp/O2
0.5 2.5 2.6 0.3 / 22.4 2.0 / 13.63 0.4 3.7 1.2 / 17.1 2.1 / 13.75 1.3 4.4 3.2 / 15.1 2.7 / 14.110 4.0 4.2 4.0 / 14.6 3.9 / 14.515 4.0 4.2 3.9 / 14.4 3.9 / 14.520 3.9 4.2 4.0 / 12.8 4.0 / 14.325 4.0 4.2 3.9 / 1.8 4.2 / 2.730 4.2 4.3 3.5 / 0.0 3.6 / 0.032 3.3 / 0.0 3.2 / 0.035 3.0 / 0.0 3.1 / 0.0
Chlorophyll a and primary production of phytoplankton in human impacted and natural
lakes
Lake, period Chl a, mgm-3 PP, mgCm-3d-1
Glubokoye 76-77
0.1-2.10.5
0.1-26.12.8
Stancionnoye76-77
- 2.7-81.528.2
Verkhneye 76-77
<0.05-0.40.07
0.1-2.00.6
Pomornik 76-77
0.1-0.90.3
0.1-2.50.8
Lakes had stronger impact in 60s, later sewage and wastes were removed into sea
● In 1967-68 the 2 impacted lakes revealed (MacNamara 1970):
● P-PO4 65-460 µg P/l
● N-NH4 620-1320 µg N/l
● Phytoplankton PP 140-370 mgC m-3day-1
● In 1988-89: ● These characteristics were at 1-2 orders of
magnitude lower levels
In 1988 this recreation activity had only a minor and transitory impact on a lake from
where drinking water was pumped
4 stations & road network on ca 5 km2 with many lakes have various impacts
● Change of meltwater flow patterns by road paving resulting:
● Water inflow volumes into lakes changed● Salinity of lake water changed
● Rock crushing by vehicles:● Increased inflow of silt with meltwater and -
decrease of transparency in lake waters● Increased leaching of solutes from crushed rock -
- salinity increase in surface & lake waters
The road far side of small lake: chanelling water flow, rock crushing, increased inflow of water and solutes into lakes
Redirected inreased inflow has progressively desalienated Heart Lake
where sediments pre-dating the LGM were cored (Hodgson et al. 2001)
Monitoring meltwater flows on surface and subsurface (piezometers in active
layer) showed that:● Max levels of DIN and DRP were much
higher in impacted than natural catchments: e.g. 2000 vs 315 µgN/l in subsurface flows; 46 vs 29 µgP/l in surface flows or 108 vs 3 µgN/l of N-NO
2in surface flows
● Max conductivity levels steeply higher in impacted than natural catchments: 4400 vs 380 µS/cm in subsurface flows 2280 vs 230 µS/cm in surface flows
Increased nutrient and conductivity levels were found at all stations in the LH:
Progress I and II, Zhong Shan, Law Base● Their origins had been:
waste (grey) water and urine, chemicals, building materials – direct inputs from stations; rock crushing by tracked vehicles and subsequent increased weathering, showed by silt increases
● Activities causing these changes: happened before Madrid Protocol came into force on 17 January 1998; unlikely that they changed radically after the date
Meltwater flowing on surface and subsurface on slope ZhongShan-No
Worries Lake much enriched with salts and nutrients
2 J
an
11
Jan
13
Jan
17
Jan
24
Jan
31
Jan
0200400600800
1000
Co
nd
uct
ivit
y (
µS
/cm
)
-25-20-15-10-5
0
a Lake No Worries, station inflow2
Jan
19 J
an
26 J
an
31 J
an
0
1000
2000
3000
Con
duct
ivit
y (
µS
/cm
)
b Lake No Worries, piezometers
2 J
an
6 J
an
11
Jan
13
Jan
17
Jan
24
Jan
29
Jan
0
100
200
300
400
500
0
20
40
60
80
100
120
a Station inflow
6 J
an
11 J
an13 J
an
17 J
an19 J
an
24 J
an
27 J
an29 J
an31 J
an
4 F
eb5 F
eb0
500
1000
1500
2000
0
20
40
60
80
100
120
b Piezometers
N-NH4
N-NO2
N-NO3
DRP
N-NH4
N-NO2
N-NO3
N-N
H4, N
-NO
3 (g
l-1)
N-N
H4, N
-NO
3 (g
l-1)
N-N
O2, D
RP
(g
l-1)
N-N
O2, D
RP
(g
l-1)
DRP
No Worries Lake at Zhong Shan the most impacted lake at LH: inflow of silt, salts, nutrients, thermal pollution
Consequenses of human impact in No Worries Lake
● Sharp decrease in transparency with silt inflow● Warming lake water, prolonged ice-free period● Temperature increase with depth changed to
temperature decrease with depth● Water salinity increase● Increased inflow of organics, nutrients and
warming have promoted heterotrophic microbial activity (Ellis-Evans et al. 1997)
An example of deep, even profound but still very limited impact of scientific
activity in a lake catchment...
...and tourists invading LH in big numbers (over 100 on a day). Their impact on lakes
was limited to footprints on lakeside...