Meso-scale barrier estuary disturbance, response and recovery behaviour: Evidence of system equilibrium and resilience from high-resolution particle size analysis

• Published in: Holocene (Sevenoaks) 2014-03, Vol.24 (3), p.357-369
• Main Authors: Clarke, David W, Boyle, John F, Lario, Javier, Plater, Andrew J
• Format: Article
• Language: English
• Subjects: Brackish; Estuaries; Paleoecology; Particle size; Wetlands
• ISSN: 0959-6836; 1477-0911
• DOI: 10.1177/0959683613518597

Establishing the future trajectories of coastal wetlands, especially the nature of their disturbance, response and recovery regimes, is of critical importance for a wide range of stakeholders and environmental managers. Reconstructing meso-scale behaviour in coastal environments can serve to attune coastal resource management strategies to natural scales of system operations, thus fostering genuine sustainability. Sediments from Pescadero Marsh, a back-barrier coastal wetland in California, were analysed down-core for their particle size distribution in consecutive 2-mm sections. The particle size data reflect changing hydrodynamics in the back-barrier area driven by past variations in barrier coherence. When considered together, the down-core mean particle size trend and particle size distribution curve styles provide considerable insight into meso-scale system behaviour, revealing barrier/back-barrier disturbance–response–recovery regimes, regime shifts and the role of aperiodic high-energy events in disturbing these regimes. Over sub-annual and multi-annual time periods, the behaviour of the Pescadero system was consistently characterised by both dynamic response to disturbance and recovery through negative feedback. Furthermore, over the duration of the analysed core section, that is, 1200–2300 years, the system was determined to have adopted a series of static equilibrium states. The barrier estuary behaviour reconstructed from the Pescadero sediment record is indicative of innate environmental resilience.