Chapter 3
The Use of Scleractinian Corals
for Heavy Metal Studies
Abstract Scleractinian corals belong to the phylum Cnidaria, class Anthozoa and
order Scleractinia and are the architects of coral reefs; therefore a good representative
of environmental changes. Their skeletons assimilate records of the presence and
concentrations of certain metals over centuries without being killed by the relatively
high levels present in the marine environment. Corals reproduce both sexually and
asexually. Environmental factors such as water chemistry, sedimentation, pollution
and surface temperature induce scleractinian corals to incorporate the heavy metals
in their living parts and skeletons. Heavy metals get incorporated into the coral
skeleton through substitution of dissolved metal species via calcium substitution and
once incorporated into the coral skeleton, the metals remain embedded forever since
the new growth covers the old carbonate surface. Once incorporated within the coral,
heavy metals can result in acute or chronic toxicity causing lethal effects or long-term
impacts to key biological processes of corals.
Keywords Scleractinian corals · Coral reproduction · Calcium substitution ·
Heavy metals
3.1 Scleractinian Corals
Scleractinian corals belong to the phylum Cnidaria; class Anthozoa and order scleractinia. Scleractinian corals have a mutualistic relationship with endosymbiotic
dinoflagellates in the genus Symbiodinium (referred to as ‘zooxanthallae’-discussed
in Chap. 2) and are the architects of coral reefs. Being sedentary in nature, they
become good representatives and indicators of their environment and its related
environmental changes and thus are able to provide valuable information. Boboria
et al. (2021) agree that stationary sedentary organisms are more beneficial to use than
the mobile organisms such as fish, when dealing with heavy metals in the marine
environment. In addition to this, these corals are ample throughout the study area,
are able to accumulate the pollutants without being killed by comparatively high
levels encountered in the marine environment and are sufficiently long lived, thus
adequate skeleton can be obtained for analysis and thin sections (El-Sorogy et al.
© The Author(s), under exclusive license to Springer Nature Switzerland AG 2021
S. B. Shah, Heavy Metals in Scleractinian Corals, SpringerBriefs in Earth Sciences,
https://doi.org/10.1007/978-3-030-73613-2_3
55
The Use of Scleractinian Corals
for Heavy Metal Studies
Abstract Scleractinian corals belong to the phylum Cnidaria, class Anthozoa and
order Scleractinia and are the architects of coral reefs; therefore a good representative
of environmental changes. Their skeletons assimilate records of the presence and
concentrations of certain metals over centuries without being killed by the relatively
high levels present in the marine environment. Corals reproduce both sexually and
asexually. Environmental factors such as water chemistry, sedimentation, pollution
and surface temperature induce scleractinian corals to incorporate the heavy metals
in their living parts and skeletons. Heavy metals get incorporated into the coral
skeleton through substitution of dissolved metal species via calcium substitution and
once incorporated into the coral skeleton, the metals remain embedded forever since
the new growth covers the old carbonate surface. Once incorporated within the coral,
heavy metals can result in acute or chronic toxicity causing lethal effects or long-term
impacts to key biological processes of corals.
Keywords Scleractinian corals · Coral reproduction · Calcium substitution ·
Heavy metals
3.1 Scleractinian Corals
Scleractinian corals belong to the phylum Cnidaria; class Anthozoa and order scleractinia. Scleractinian corals have a mutualistic relationship with endosymbiotic
dinoflagellates in the genus Symbiodinium (referred to as ‘zooxanthallae’-discussed
in Chap. 2) and are the architects of coral reefs. Being sedentary in nature, they
become good representatives and indicators of their environment and its related
environmental changes and thus are able to provide valuable information. Boboria
et al. (2021) agree that stationary sedentary organisms are more beneficial to use than
the mobile organisms such as fish, when dealing with heavy metals in the marine
environment. In addition to this, these corals are ample throughout the study area,
are able to accumulate the pollutants without being killed by comparatively high
levels encountered in the marine environment and are sufficiently long lived, thus
adequate skeleton can be obtained for analysis and thin sections (El-Sorogy et al.
© The Author(s), under exclusive license to Springer Nature Switzerland AG 2021
S. B. Shah, Heavy Metals in Scleractinian Corals, SpringerBriefs in Earth Sciences,
https://doi.org/10.1007/978-3-030-73613-2_3
55