Terry M. Bella
The primary producers (converters of solar energy to chemical energy) in terrestrial ecosystems are grasses and trees, in the ocean they are phytoplankton. Phytoplankton are in jeopardy because many of them produce a calcium carbonate shell. These microscopic photosynthetic organisms are crucial components to food webs and oxygen production. On a positive side, many algae and plant species show increased productivity in situations of higher acidity because of the increase in available carbon dioxide. The deciding factor between which species does well and which does not ties back to the presence of a shell, something more difficult to construct in a more acidic ocean.
Central to any food web are the primary converters, they are taking solar energy and essentially converting it into chemical energy. They use solar energy to drive reactions that build sugars, thus storing energy in chemical bonds. This energy is passed through the ecosystem when the primary converter is then consumed. It is of massive consequence to loose primary productivity of the largest ecosystem on the planet. Some of these organisms will adapt. Many have features that facilitate quick adaptation, such as high reproductive rates and sexual reproduction. Overall though, the landscape is going to change, the diversity will decrease, leaving the ocean’s ecosystem even less stable as ecosystem stability is dependent upon diversity. An organism called a coccolithophore has been one of interest in research as it is widely dispersed in our oceans and is a shell forming photosynthesizing algae.
Some algal species that are paramount to our reefs are not responding well to increased acidity. These algal species are called coralline algae’s and they build shells. Coralline algae have two important roles in the reef ecosystem. They help to bind corals together, acting as sort of bridge or cement between adjacent corals. These algae are easy to identify when you are viewing a reef aquarium, they are the purple film or layer that is on the glass and rock work. Coralline algae also supply a location for a larval coral to seed. Although some coral may not be adversely affected by a more acidic condition, if their larvae cannot ever seed (attach) to the reef, the future of the reef is in jeopardy. Coralline algae are particularly susceptible because the shell they excrete is that of high-magnesium calcite, an even more soluble compound than the aragonite produced by corals (11).