Post on 07-Jul-2020
Environmental threats for the Caspian Sea
Frank Riedel, Freie Universität Berlin, Interdisciplinary Centre for Ecosystem Dynamics
Environmental threatsfor the Caspian Sea
Geological setting
Resources
Food web
Examples of impact
Caspian conservation
Perspectives
From Scotese, 2005
Early Oligocene, 34-32 Ma ago (from Popov et al., 2004)
Middle-Late Pliocene, 3.4-1.8 Ma ago (from Popov et al., 2004)
Characteristics:Relic of ancient oceanEndorheic basinSurface area:
~370.000 km2
Altitude:~-27 m a.s.l.
Main rivers:Volga, Ural, Kura,Samur, Safid
Bathymetry:Shallow north plustwo deep basins(max. depth 1020 m)
Hydrology:salinity gradientsmeso- to eutrophicoxygen saturation
Climatic setting:high evaporation
Plankton and clay deposition under anoxic conditions
Black organic shale – source rock
Sedimentation - compactation
Impermeable sealing sediments
Temperature – oil formation
Tectonics – oil migration
From Scotese, 2005
Fossil versus living resources?
Fossil versus living resources?
The example of the sturgeon
Huso huso Acipenser persicus
Acipenser stellatus CAVIAR
A sturgeon poacher at Sulak, Dagestan (2005)
Seals - on top of the Caspian Sea foodweb
Seals - on top of the Caspian Sea foodweb
Invasivespecies
Contamination fromoffshore oil and gas activities
Environmental threats for the Caspian Sea
The main emerging problemsrecognized in the late 1990s
Endemic species versusalien invasive species
Mnemiopsis
Endemic species versusalien invasive species
Oil and gas exploration: Offshore and onshore pollution
The Caspian Conservation Convention (UNEP)
„Reduce industrial pollution. … a particular challengewill be to address the potential consequences of
the recent growth in oil and gas production“.
„Protect marine living resources. … best-known exampleof the over-exploitation of these biological resources is
the dramatic decline of the sturgeon fisheries …“.
Address the the problem of fluctuating water levels
Colloborate on emergency response
Monitor and assess the environment
So what do we need?
Evaluation of the researchon the interactions betweenthe Caspian Sea foodweband pollution, with specialfocus on the oil and gas activities and sustainable
sturgeon fisheries
This is not the end butthe start for discussion
Thank you for your attention!
Lake level changes
Source: Google Earth, 2005
Dune formation from ancient lake sediments (Dagestan, 2005)
Source: Google Earth, 2005