Evaluations of service delivery interventions with contemporaneous controls often yield null results, even when the intervention appeared promising in advance. There can be many reasons for null results. In this paper we introduce the concept of a 'rising tide' phenomenon being a possible explanation of null results. We note that evaluations of service delivery interventions often occur when aw...

Linkages between predators and their prey across the subtidal-intertidal boundary remain relatively unexplored. The influence of tidal phase, tidal height and wave exposure on the abundance, population structure and stomach contents of mobile predatory crabs was examined on rocky shores in southwest Britain. Crabs were sampled both during the day and at night using traps deployed at high tide a...

The Banc d’Arguin in Mauritania is an area characterised by shallow waters and tidal flats with extensive seagrass beds. The aim of this study was to determine the role of the Banc d’Arguin tidal flats as a habitat and a nursery for shrimps. Shrimps were sampled in the Baie d’Aouatif in the intertidal (ponds, Zostera noltii seagrass beds and bare sediment) with a push net during high and low ti...

Excerpt] The Manifesto of the Communist Party, published 150 years ago in London in February 1848, is one of the most influential and widely-read documents of the past two centuries. The historian A. J. P. Taylor (1967, p. 7) has called it a "holy book," and contends that because of it, "everyone thinks differently about politics and society." And yet, despite its enormous influence in the 20th...

Brown tides of Aureococcus anophagefferens occur in shallow mid-Atlantic bays in the USA and attain peak summer densities of ~1000 to 2800 cells μl–1. Blooms coincide with the period of spawning and planktotrophic larval development of the hard clam Mercenaria mercenaria, a commercially important bivalve in the region. This laboratory study investigates the effects of A. anophagefferens (toxic ...

A fundamental study by Ens et al. (1992, Journal of Animal Ecology, 61, 703) developed the concept of two different nest-territory qualities in Eurasian oystercatchers (Haematopus ostralegus, L.), resulting in different reproductive successes. "Resident" oystercatchers use breeding territories close to the high-tide line and occupy adjacent foraging territories on mudflats. "Leapfrog" oystercat...

Water level reduction with GNSS [FIG Commission 4 Working Group 4.2 2006, Dodd and Mills 2011] requires the availability of the ellipsoidal heights of CD, i.e. the Lowest Astronomical Tide (LAT) as adopted by the International Hydrographic Organization [International Hydrographic Organization, 2011, Technical Resolution 3/1919]. LAT is defined as the lowest tide level to occur under average met...

Vale, L. M. and Dias, J. M., 2011. The effect of tidal regime and river flow on the hydrodynamics and salinity structure of the Lima Estuary: Use of a numerical model to assist on estuary classification, SI 64 (Proceedings of the 11th International Coastal Symposium), 1604 – 1608. Szczecin, Poland, ISSN 0749-0208 The purpose of this work is to characterize the hydrodynamics of the Lima estuary ...

-