Estuaries anoxia

Of all the marine ecosystems, temperate estuaries seem to be undergoing the most degradation. Evidence for this is seen in (1) increased sedimentation and turbidity, (2) more extended and expansive episodes of hypoxia or anoxia, (3) loss of seagrasses and dominant suspension feeders, primarily bivalves, and (4) a higher frequency and duration of nuisance and toxic algal blooms, jellyfish infestations, and fish kills. Overall, these... 

Luther III, G.W., Ma, S., Trouwborst, R., Glazer, B., Blickley, M., Scarborough, R.W., and Mensinger, M.G. (2004) The roles of anoxia, H2S and storm events in fish kills of dead-end canals of Delaware inland bays. Estuaries 27, 551-560. 

Westman, P., Borhendahl, J., Bianchi, T.S., and Chen, N. (2003) Probable causes for cyanobacterial expansion in the Baltic Sea role of anoxia and phosphorus retention. Estuaries 26, 680-689. 

In shallow estuaries and lagoons subject to macroalgal blooms, the collapse of blooms and subsequent turnover of N can have major ecosystem level effects. Release of organic N may alter food webs toward heterotrophic bacteria pathways (Valiela et al, 1997), depleting water and sediments of oxygen. If severe, the result is die-off of resident fish and invertebrates. In addition, sediment anoxia may cause... 

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