Effects of sediment exposure on corals: a systematic review of experimental studies

Table 6 Coral response thresholds (NOAEL/LOAEL) of all studies concerning the effects of suspended sediment on corals

Coral age class	Binary coral response	# Treatment groups* (controls included/excluded)	# Studies/articles with binary data	# Species/genera with binary data	NOAEL threshold		LOAEL threshold
Coral age class	Binary coral response	# Treatment groups* (controls included/excluded)	# Studies/articles with binary data	# Species/genera with binary data	Concentration (mg/L)	Duration	Concentration (mg/L)	Duration
Gametes	Reduced fertilization success?	110/86	10/6	4/2	25.0	–	30.4	–
Larvae	Larval mortality?	63/52	7/4	5/2	29.5	–	30.0	–
Larvae	Limited settlement?	30/20	7/4	4/3	34.6	–	57.8	–
Juveniles	Physiological limitation?	20/15	2/1	3/2	10.0	0	10.0	1 h
Juveniles	Recruit mortality?	16/9	2/2	4/3	100.0	40 days	100.0	40 days
Adults	Reduced P/R ratio?	49/34	3/3	4/4	35.8	2 h	35.8	2 h
	Reduced photosynthetic efficiency?	238/180	6/5	8/6	35.8	56 days	35.8	56 days
	Local bleaching?	92/54	8/7	10/6	3.2	1 day	3.2	1 day
	Reduced growth rate?	79/47	7/5	12/12	49.0	31 days	58.6	31 days
	Small tissue necroses?	210/147	4/4	8/6	3.2	14 days	3.2	14 days
	Large tissue necroses?	210/147	4/4	8/6	29.1	84 days	29.1	84 days
	Total colony mortality?	272/176	8/6	17/14	29.1	40 days	29.1	40 days
Adults	ANY MORTALITY?*	272/176	8/6	17/14	3.2	14 days	3.2	14 days
Adults	ANY ADVERSE EFFECT?*	360/244	14/11	21/16	3.2	2 h	3.2	2 h
All	ANY MORTALITY?*	376/261	19/11	21/15	3.2	12 h	3.2	12 h
All	ANY ADVERSE EFFECT?*	585/423	37/20	26/18	3.2	0	3.2	1 h

*A ‘treatment group’ is an experimental unit of corals exposed to the same exposure conditions within a study—these may be control (no sediment exposure) or treatment conditions of differing exposure concentrations and/or durations. ‘Physiological limitation?’ for juvenile corals indicates either reduced P/R ratio, reduced photosynthetic efficiency, or reduced growth rate. These are combined here because they represent the physiological results from only one article. = Double dashes ‘–' indicate that data were irrelevant. Any adverse effect is defined as any response of a coral individual, colony, or treatment group that may negatively affect a coral’s fitness and/or survival. These adverse effects may include physiological changes (e.g., reduced growth or photosynthetic rates), bleaching, tissue necrosis, and colony mortality. Any mortality is inclusive of death of tissue (small and large necroses) or of the entire coral colony, and thus excludes sublethal coral responses

ISSN: 2047-2382