42
2 Coral Reef Ecosystem
Fonseca et al (2019) reported that Cu contamination could cause ecological and
economic disservice associated with the loss of integrity of coral reefs. In conjunction with other stressors such as ocean acidification, Cu leads to the activation of
antioxidant system in sea anemones and corals (Siddiqui and Bielmyer-Fraser 2015;
Bielmyer-Fraser et al. 2018). This occurs because Cu has been shown to cause
the generation of ROS which leads to the degradation of macromolecules such as
proteins, lipids and DNA (Chang et al. 1996; Luschak 2011). DMSP is important to
coral reefs yet the variation on the DMSP levels could be dependent on the type of
metal the corals are being exposed to.
2.6 Summary
Coral reef ecosystems thrive in nutrient poor waters and are highly diverse. The
mutualistic symbiosis between the coral polyp and zooxanthallae helps form the
trophic and structural foundation of coral reef ecosystems. Coral reefs substantiate
to be beneficial in a variety of aspects such as providing nurseries to juvenile fish,
abode for drug exploitation, stabilizing coastlines and a source of livelihood for many
people.
However, coral reef ecosystems are under threat both naturally as well as anthropogenically. Under stress, due to altering environmental conditions, corals expel
the symbiotic zooxanthallae, thus leading to bleaching. Pollutants, nutrients, sedimentation, and declining water quality adversely impacts corals leading to burial
and smothering, decreased calcification rates and reduced recruitment; thus leading
to the global decline of the coral reefs. Climate change also contributes to coral
bleaching events and alters ocean chemistry. Oceanic acidification occurs when pH
is lowered, thus corals cannot absorb the calcium carbonate that is needed to maintain their skeletons. Corals and polyps excrete DMSP naturally and production of
DMSP increases when corals are subjected to higher water temperatures. DMSP is
a precursor of DMS, which has a profound impact on the climate system.
Combined effects of multiple interacting stressors lead to the decline of coral
reefs. In an era of climate change and ocean acidification, it becomes paramount to
understand the biological effects of metal exposure to corals.
References
Albright R, Cooley S (2019) A review of interventions proposed to abate impacts of ocean
acidification on coral reefs. Reg Stud Mar Sci 29: https://doi.org/10.1016/j.rsma.2019.100612
Allemand D, Osborn D (2019) Ocean acidification impacts on coral reefs: From sciences to
solutions. Reg Stud Mar Sci 28: https://doi.org/10.1016/j.rsma.2019.100558
Anthony K (1999a) Coral suspension feeding on fine particulate matter. J Exp Biol Ecol 232:85–106
Anthony K (1999b) A tank system for studying benthic aquatic organisms at predictable levels of
turbidity and sedimentation: case study examining coral growth. Limnol Oceanogr 44:1415–1422
2 Coral Reef Ecosystem
Fonseca et al (2019) reported that Cu contamination could cause ecological and
economic disservice associated with the loss of integrity of coral reefs. In conjunction with other stressors such as ocean acidification, Cu leads to the activation of
antioxidant system in sea anemones and corals (Siddiqui and Bielmyer-Fraser 2015;
Bielmyer-Fraser et al. 2018). This occurs because Cu has been shown to cause
the generation of ROS which leads to the degradation of macromolecules such as
proteins, lipids and DNA (Chang et al. 1996; Luschak 2011). DMSP is important to
coral reefs yet the variation on the DMSP levels could be dependent on the type of
metal the corals are being exposed to.
2.6 Summary
Coral reef ecosystems thrive in nutrient poor waters and are highly diverse. The
mutualistic symbiosis between the coral polyp and zooxanthallae helps form the
trophic and structural foundation of coral reef ecosystems. Coral reefs substantiate
to be beneficial in a variety of aspects such as providing nurseries to juvenile fish,
abode for drug exploitation, stabilizing coastlines and a source of livelihood for many
people.
However, coral reef ecosystems are under threat both naturally as well as anthropogenically. Under stress, due to altering environmental conditions, corals expel
the symbiotic zooxanthallae, thus leading to bleaching. Pollutants, nutrients, sedimentation, and declining water quality adversely impacts corals leading to burial
and smothering, decreased calcification rates and reduced recruitment; thus leading
to the global decline of the coral reefs. Climate change also contributes to coral
bleaching events and alters ocean chemistry. Oceanic acidification occurs when pH
is lowered, thus corals cannot absorb the calcium carbonate that is needed to maintain their skeletons. Corals and polyps excrete DMSP naturally and production of
DMSP increases when corals are subjected to higher water temperatures. DMSP is
a precursor of DMS, which has a profound impact on the climate system.
Combined effects of multiple interacting stressors lead to the decline of coral
reefs. In an era of climate change and ocean acidification, it becomes paramount to
understand the biological effects of metal exposure to corals.
References
Albright R, Cooley S (2019) A review of interventions proposed to abate impacts of ocean
acidification on coral reefs. Reg Stud Mar Sci 29: https://doi.org/10.1016/j.rsma.2019.100612
Allemand D, Osborn D (2019) Ocean acidification impacts on coral reefs: From sciences to
solutions. Reg Stud Mar Sci 28: https://doi.org/10.1016/j.rsma.2019.100558
Anthony K (1999a) Coral suspension feeding on fine particulate matter. J Exp Biol Ecol 232:85–106
Anthony K (1999b) A tank system for studying benthic aquatic organisms at predictable levels of
turbidity and sedimentation: case study examining coral growth. Limnol Oceanogr 44:1415–1422