Clownfish Ecosystem Impacts

(http://static.guim.co.uk/sys-images/Guardian/About/
General/2011/2/23/1298488013408/Coral-reef-near-Fiji-007.jpg)

As previously mentioned, clownfish rely on the ecosystem supported by the world's coral reefs. Without proper coral reef homes, clownfish may struggle to find acceptable sea anemone hosts. Additionally, less expansive coral reefs can leave clownfish unprotected and more vulnerable to natural predators.

Climate Change Impacts on Clownfish Habitats

Ocean Acidification

In order for coral reefs to grow, the coral must be able to perform calcification to grow its hard skeleton. According to recent studies "coral calcification decreases with declining pH" (De'ath 2009). Since a decreased pH means a greater proportion of hydrogen ions, it also means more hydrogen ions will react with carbonate ions and reduce the saturation of usable carbonate for coral calcification (Kleypas 2006). In a study by the Australian Institute of Marine Sciences, it was shown that coral calcification decreased by 14.2% in the last 20 years (De'ath 2009).

Increased Temperature

                "Marcelja 2010"

As indicated by the above graph, sea surface temperature (SST) has increased since the beginning of the industrial revolution and continues to increase today. The rise in temperature has been shown to be directly correlated with anthropogenic actions. Much as ocean acidification can negatively affect coral reefs, increased temperature also causes damage. Since coral reefs live in the upper realms of their thermal limits, small increases in temperature have major effects. The most significant effect of increased temperature is the occurrence of coral bleaching, which can lead to coral death. When temperature increases, the algae the live in a symbiotic relationship with the coral can no longer produce food. This causes the coral to expel the algae and leaves the coral malnourished (Buchheim 1998, Microdocs).

Consequences for the Clownfish Ecosystem 

Since increased ocean acidification and SST indicate probable decrease in size and magnitude of future coral populations, there are possible dire implications for clownfish populations. Unfortunately, clownfish live within an ecosystem that largely relies on expansive coral populations. Their host anemones use the coral as an anchor as well as an attractant for diverse fish species. The current biodiversity of the ecosystem will not be sustained without successful coral growth. It is possible that clownfish populations could exhibit range shifts in response to changes in their ecosystem. Their ranges may contract and they may also experience trophic mismatch as their prey and/or their predators also show range shifts.