Thursday, May 01, 2014

Sheep, Sedges, and Sustainability

 Basra, Iraq, 26 April 2014

Image (c) Jennifer R. Pournelle. Sheep grazing near the U. Basra Marine Science Center Field Station, Hareer,

The first field day was spent viewing firsthand the opportunities and limits for broad-scale freshwater marsh restoration outside Basra City. This stand of cattails (Typha), rushes (Juncus), and bulrushes (Scirpus) is scarcely four years old - re-formed when brackish irrigation return water was allowed to re-flood areas desiccated for over a decade. This mix of marshy plants provides good grazing, and supports local production of mutton, wool, and dairy products.
However, extreme, and unpredictable, fluctuations in salinity due to upstream water releases are more than the date and fruit orchards that used to cover this plain can bear - new trees that manage to survive seldom bear fruit. Likewise, those random fluctuations kill off both fresh- and salt- tolerant fish fry. Unlike in a natural estuary, subject to predictable daily ebb and flow, they cannot follow a salt gradient within their range of tolerance.

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