Modern agriculture has transformed Earth's surface, and one consequence has been the increase in continental material that is eroded and transported to the oceans. There it poses particular hazards to reef-building corals, by decreasing the availability of light and interfering with feeding.

In this article Julia Cole, of the University of Arizona, describes a study in this week's Nature showing that sedimentation on Australia's great barrier reef increased dramatically following European settlement and agricultural expansion in northeast Australia. Corals in Kenya tell a similar tale of erosion exacerbated by the imposition of colonial agricultural practices in the early decades of the twentieth century.

Reef preservation efforts often focus on stemming the impact of locally significant threats, such as those from destructive fishing, mining and tourism. But mitigating large-scale reef stress — including that caused by changes in land use — will require regulation of the driving forces of global environmental change.

Link to full Nature news and views article (free access)

Reference: Nature 421, 705 (2003)

See also:

Link to Nature research paper: Coral record of increased sediment flux to the inner Great Barrier Reef since European settlement (free access)

Photo credit: Florida Keys National Marine Sanctuary