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