Publication Date:
2021-05-19
Description:
Global change is defined here for this review as changes caused by increasing greenhouse gas emissions resulting in a high CO2 world and the direct and indirect changes that ensue. Increasing green house gas emissions are causing three major impacts on the ocean: warming sea surface temperature (SST), ocean acidification and deoxygenation (Turley et al 2011). The latter two are poorly understood at present, particularly in Eastern Africa. Secondary impacts include sea level rise due to melting polar ice caps. Coral bleaching and death caused by SST rise has been extensively studied and measured (HoeghGuldberg 1999; Hughes et al. 2003), including in the WIO (Obura 2005, McClanahan 2009), with likely ecosystem phase shifts as coral reefs become dominated by macroalgae (brown algae such as Turbinaria, Sargassum spp.) (Bellwood et al. 2004; Hughes et al. 2005). Ocean acidification is likely to have enormous impacts on marine resources and hence fisheries (Turley et al. 2011), as ocean chemistry is changed and thus any marine organisms that rely on Ph sensitive chemical reactions will be affected. This field is still relatively new and early reports predict trophic level shifts as organisms with calcium carbonate skeletons, e.g molluscs, corals, are compromised. Deoxygenation is caused by ocean warming (oxygen becomes less soluble) which will result in less growth of most marine organisms and a shift to low oxygen tolerant organisms, often microorganisms. Coastal environments and people are also undergoing changes that are directly related to human pressures caused by development and other activities. These include increasing population, mechanisation (eg in fisheries), industrialisation (eg ports and coastal cities), pollution, and extraction of oil and gas.
Description:
Published
Keywords:
Global warming
;
Sea level changes
;
Greenhouse effect
;
Mangroves
;
Surface temperature
Repository Name:
AquaDocs
Type:
Report
,
Not Known
Format:
50pp.
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