@article {Hourston:2009rc,
	title = {Spatial and seasonal variations in the ecological characteristics of the free-living nematode assemblages in a large microtidal estuary},
	journal = {Estuarine Coastal and Shelf Science},
	volume = {82},
	year = {2009},
	pages = {309-322},
	publisher = {ACADEMIC PRESS LTD ELSEVIER SCIENCE LTD},
	address = {24-28 OVAL RD, LONDON NW1 7DX, ENGLAND},
	abstract = {This study has determined the ways in which the density, number of species, species composition and trophic structure of free-living nematode assemblages in the subtidal waters of a large southern hemisphere microtidal estuary change spatially and seasonally, and has explored whether those four biotic characteristics are related to certain environmental factors. Based on data derived from samples collected seasonally at 12 sites throughout the estuary, the densities and number of species of nematodes decreased progressively with distance from estuary mouth, to reach a minimum at sites where salinities were most variable. and then increased slightly in the uppermost part of the estuary where salinities were least. Densities were also generally greatest in spring, due largely to increases in the abundance of epistrate-grazing species at this time and thus when the amount of primary food (microphytobenthos) peaked. The spatial distribution of the composition of the nematode assemblages was closely correlated with salinity and, to a lesser extent, grain-size composition and amount of particulate organic material (\%POM) in the sediment. Although species composition changed sequentially along the estuary, the change was particularly pronounced between sites above and below the area where salinities started to decline markedly and become more variable and \%POM increased markedly. This reflected, in particular, far greater abundances of Spirinia parasitifera at the six downstream sites and of Theristus sp. 1 at the six sites further upstream. Species composition underwent pronounced seasonal cyclical changes at all sites, presumably reflecting interspecific differences in the timing of peak reproduction and thus of recruitment. The trophic structure of the nematode assemblages changed both spatially and temporally in relation to the relative abundance of different food sources. Thus, for example, non-selective deposit feeders, such as Theristus sp. 1, dominated samples in the upper estuary, where \%POM was by far the greatest, and was rare or absent at downstream sites. Conversely, epistrate grazers, such as species of the Chromadoridae, were most abundant at downstream sites in spring, when the density of the microphytobenthos reached its maximum. (C) 2009 Elsevier Ltd. All rights reserved.},
	keywords = {environmental factors, microtidal estuary, nematodes, number of species and density, species and trophic compositions},
	doi = {DOI 10.1016/j.ecss.2009.01.018},
	author = {Hourston, M. and Potter, I. C. and Warwick, R. M. and Valesini, F. J. and Clarke, K. R.}
}
@article {Widdicombe:2009qr,
	title = {Effects of CO2 induced seawater acidification on infaunal diversity and sediment nutrient fluxes},
	journal = {Marine Ecology-Progress Series},
	volume = {379},
	year = {2009},
	pages = {59-75},
	publisher = {INTER-RESEARCH},
	address = {NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY},
	abstract = {A mesocosm experiment was conducted to quantify the effects of short- (2 wk) and long-term (20 wk) exposure to acidified seawater on the structure and diversity of macrofaunal and nematode assemblages in 2 different sediment. types. The impact of acidified seawater on sediment nutrient fluxes was also determined. Using carbon dioxide (CO2) gas, seawater was acidified to pH 7.3 (mimicking ocean acidification), 6.5 or 5.6 (mimicking leakage from a sub-seabed CO2 store site). Control treatments were maintained in natural seawater [pH approximate to 8.0). Exposure to acidified seawater significantly altered community structure and reduced diversity for both macrofaunal and nematode assemblages, However, the impact on nematodes was less severe than that on macrofauna. While the communities in both sediment types were significantly affected by changes in seawater pH, impacts on sandy sediment fauna were greater than those on muddy sediment fauna. Sandy sediments also showed the greatest effects with respect to nutrient fluxes. In sand, the efflux of nitrite, nitrate and silicate decreased in response to increased acidification while the efflux of ammonium increased, In mud, acidification increased the efflux of ammonium but had no effect on the other nutrients. We conclude that both leakage from carbon storage and ocean acidification could cause significant changes in the structure and diversity of coastal sediment communities. Lowered seawater pH could also affect nutrient cycling directly by altering bacterial communities and indirectly through impacts on the abundance and activity of key bioturbators.},
	keywords = {Biodiversity, Carbon storage, Macrofauna, meiofauna, Nutrient flux, Ocean acidification},
	doi = {DOI 10.3354/meps07894},
	author = {Widdicombe, S. and Dashfield, S. L. and McNeill, C. L. and Needham, H. R. and Beesley, A. and McEvoy, A. and Oxnevad, S. and Clarke, K. R. and Berge, J. A.}
}
