Title
From cane to coral reefs- Ecosystem Connectivity and Downstream Responses to Land Use Intensification
Author(s)
Stacey D. Jupiter
Abstract
Major trends emerging from integration of contemporaneous terrestrial changes, marine geochemical proxies and climate records include: 1. A 33% net decline (1972-2004) of forests on alluvial plains as farms encroached into riparian zones; and a 22% net decline (1948-2002) of tidal mangroves in the estuary. 2. Ba/Ca correlations with Pioneer River discharge were influenced by wind direction and strength; but there was no apparent temporal change in Ba/Ca since 1946. The absence of enrichment in mean inshore Ba/Ca ratios (versus midshelf reefs) may be due to biological recycling by phytoplankton, which may restrict Ba availability. 3. Mean Y/Ca ratios from inshore (5 km) corals were 3.1 and 3.6 times higher than from midshelf (32 and 51 km) corals, and inshore REY abundances were ~2-5 times higher than from mishelf reefs. Inter-annual REY variation on both inshore and midshelf sites was correlated significantly with year and discharge, while long-term temporal trends in maximum annual Y/Ca, normalized to Pionee River discharge, appear to reflect both agricultural expansion and changing management practices. 4. The combination of high turbidity and high nutrient discharge from the Pioneer River may be affecting benthic community composition on both inshore and midshelf reefs.

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DMX985300000