3.3 Biogeochemistry of Scleractinian Corals
59
into the skeleton matrix being dependent on the patterns of uptake and regulation in
corals (Hardefeldt and Reichelt-Brushett 2015).
Once incorporated into the coral skeleton, the metals will remain embedded
forever since the new growth covers the old carbonate surface (St John 1974). Hence,
Shen and Boyle (1988) and Esslemont et al. (2000) mention that with continuous
changes in the marine environments, most studies have examined the accumulation
of heavy metals in coral tissues and skeletons to determine the long-term effects of
environmental factors in addition to direct anthropogenic inputs. Scleractinian corals
are the dominant structuring organisms of coral reefs, hence it becomes imperative
to understand the potential effects of trace metals on their health and reproductive
success (Reichelt-Brushett and Harrison 2005).
3.4 Ecotoxicological Studies Using Scleractinian Corals
Toxicology comprises the study of the harmful effects of toxins and anthropogenic
compounds (such as heavy metals) on living organisms. Rotchell and Ostrander
(2011) highlighted that focused toxicological studies at the subcellular/molecular
level of corals have the potential to make accessible a great deal of valuable information. Ecotoxicological testing is an operative management tool which is used to
evaluate the potential toxicity of environmental contaminants such as heavy metals
(Peters et al. 1997; van Dam et al. 2008). For instance, ecotoxicology provides a
tool in a multiple lines of evidence approach to assess the risks associated with the
emerging development of nickel and cobalt extraction in tropical and subtropical
regions of the world (e.g. Reichelt-Brushett and Hudspith 2016).
The use of corals for trace metal studies has been widely documented. A wide
range of techniques has been used to extract and measure trace metals in a variety of
coral species (Reichelt-Brushett and McOrist 2003), and hence studies are not always
directly comparable. However, it becomes necessary to mention about the various
studies as they reveal a lot of information regarding emerging pollutants such as
heavy metals and their deleterious effects on different coral species in different parts
of the world. These studies give an insight regarding metal pollution and their impacts
on scleractinian corals in various parts of the world.
Some studies have focused on the analysis of the skeleton only (Scott 1990;
Guzman and Jimenez 1992; Bastidas and Garcia 1999; Ramos et al. 2004; David
2003; Medina-Elizade et al. 2002; Guzman and Garcia 2002; Livingston and
Thompson 1971; and Runnals and Coleman 2003). Whilst for other studies, tissue and
skeleton components have been analyzed separately or combined together (Denton
and Burdon-Jones 1986; Howard and Brown 1987; Glynn et al. 1989; Harland
and Brown 1989; Esslemont 1999; Esslemont et al. 2000; Reichelt-Brushett and
McOrist 2003; and Smith et al. 2003). Studies have also focused on the partitioning
of metals between tissues and skeleton (McConchie and Harriot 1992), and between
tissue, zooxanthellae, gametes and skeleton of selected corals (Reichelt-Brushett and
McOrist 2003).
59
into the skeleton matrix being dependent on the patterns of uptake and regulation in
corals (Hardefeldt and Reichelt-Brushett 2015).
Once incorporated into the coral skeleton, the metals will remain embedded
forever since the new growth covers the old carbonate surface (St John 1974). Hence,
Shen and Boyle (1988) and Esslemont et al. (2000) mention that with continuous
changes in the marine environments, most studies have examined the accumulation
of heavy metals in coral tissues and skeletons to determine the long-term effects of
environmental factors in addition to direct anthropogenic inputs. Scleractinian corals
are the dominant structuring organisms of coral reefs, hence it becomes imperative
to understand the potential effects of trace metals on their health and reproductive
success (Reichelt-Brushett and Harrison 2005).
3.4 Ecotoxicological Studies Using Scleractinian Corals
Toxicology comprises the study of the harmful effects of toxins and anthropogenic
compounds (such as heavy metals) on living organisms. Rotchell and Ostrander
(2011) highlighted that focused toxicological studies at the subcellular/molecular
level of corals have the potential to make accessible a great deal of valuable information. Ecotoxicological testing is an operative management tool which is used to
evaluate the potential toxicity of environmental contaminants such as heavy metals
(Peters et al. 1997; van Dam et al. 2008). For instance, ecotoxicology provides a
tool in a multiple lines of evidence approach to assess the risks associated with the
emerging development of nickel and cobalt extraction in tropical and subtropical
regions of the world (e.g. Reichelt-Brushett and Hudspith 2016).
The use of corals for trace metal studies has been widely documented. A wide
range of techniques has been used to extract and measure trace metals in a variety of
coral species (Reichelt-Brushett and McOrist 2003), and hence studies are not always
directly comparable. However, it becomes necessary to mention about the various
studies as they reveal a lot of information regarding emerging pollutants such as
heavy metals and their deleterious effects on different coral species in different parts
of the world. These studies give an insight regarding metal pollution and their impacts
on scleractinian corals in various parts of the world.
Some studies have focused on the analysis of the skeleton only (Scott 1990;
Guzman and Jimenez 1992; Bastidas and Garcia 1999; Ramos et al. 2004; David
2003; Medina-Elizade et al. 2002; Guzman and Garcia 2002; Livingston and
Thompson 1971; and Runnals and Coleman 2003). Whilst for other studies, tissue and
skeleton components have been analyzed separately or combined together (Denton
and Burdon-Jones 1986; Howard and Brown 1987; Glynn et al. 1989; Harland
and Brown 1989; Esslemont 1999; Esslemont et al. 2000; Reichelt-Brushett and
McOrist 2003; and Smith et al. 2003). Studies have also focused on the partitioning
of metals between tissues and skeleton (McConchie and Harriot 1992), and between
tissue, zooxanthellae, gametes and skeleton of selected corals (Reichelt-Brushett and
McOrist 2003).