Question

2. Propose a simple laboratory study to investigate the ability of coral populations to ‘respond to environmental change’ items 4 & 5 (phenotypic plasticity & adaptive evolution).

As a follow up to your experiment, imagine that you are collaborating with a marine invertebrate geneticist. What would you ask them to investigate with respect to coral genomes?

Answer 1

A laboratory investigation of the ability of coral reefs responding increased oceanic acidification

Background: The coral reefs are generally found in deep oceans or warm sea-water. They are characterized by the deposition of calcium carbonate-based exoskeleton around their soft sac-like bodies. A gradual increase in their population often protected by hard-core exoskeleton make them prominent biological entities in the deep sea. Some of them look like phytoplankton and are comparatively soft in outer structure. The coral reefs are generally studied with respect to their response to the acidification of oceans. Most of the countries rely heavily on fossil fuels to meet their energy demands. Heavy usage of crude oil for extraction and purification, petroleum-based automobile, and transport industries are one of the key contributors in the global rise of atmospheric carbon dioxide. In general, increased atmospheric carbon dioxide tends to dissolve in water and lowers its pH. It results in acidification of oceans making it a very dangerous situation from the ecological point of view. In the present investigation, it is aimed to study the impact of acidified water on the behavior of coral reefs

Aim: To study the impact of water acidification on growth of coral population

Principle: Corals are deep water structures often involving calcium carbonate-based exoskeleton protecting their soft body. They are popular as model organisms to study climatic changes, acidification of seawaters.

Requirements:

• Artificial small scale aquarium with coral population
• Controlled carbon dioxide supply from CO2 cylinder
• Distilled water
• Various organic and inorganic salts, minerals etc.

Protocol:

1. Mimick marine water environment by adding various organic and inorganic salt, minerals to distilled water and set its pH close to alkaline condition or more (above 7 pH).
2. Gradually replace water from an aquarium with above artificially prepared sea environment mimicking water.
3. Provide all nutrition for the steady growth of corals as usual.
4. Under the strict supervision of laboratory guides or mentors, slowly release carbon dioxide in this artificial seawater so that sufficient carbon dioxide will be dissolved.
5. After some time, measure the pH of this water and make sure it is acidic that is below
6. Now, students need to carefully study how the coral population responds to the acidified environment.

Outcome:

• The height of corals will gradually decrease in response to the acidified environment so it is important to measure their height before and after the addition of carbon dioxide in the water.
• In addition to the above wet-lab experiment, one needs to study the coral genome as to how they respond to changing pH of sea-water. For this students may ask the following questions to the marine invertebrate geneticist pioneer in coral research.

1. Which are those upregulating or downregulation genes responsible for changed coral phenotype?
2. How to confirm that corals respond to acidification of seawater by studying their genome?
3. What could be the cellular changes occurring in response to the acidification of water?
4. What could be the impact of increasing CO2 concentration on their exoskeleton?
5. Which metabolic pathways could be affected severely by acidification?
6. Which genes of corals are responsible for sensing environmental changes?
7. How phenotype of corals would shape in light of constant fluctuation in seawater composition in terms of pH, gaseous mixture, etc?