Plankton is the most prevalent life and food source in the ocean. Phytoplankton, which carries on photosynthesis near the ocean surface, serves as food for the zooplankton and fish.
The microscopic plants that underpin all life in the oceans are likely to be destroyed by global warming. Scientists have discovered a way that the vital plankton of the oceans can be starved of nutrients as a result of the seas getting warmer. They believe the findings have catastrophic implications for the entire marine habitat, which ultimately relies on plankton at the base of the food chain.
Plankton are microscopic animals (zooplankton) and algae (phytoplankton) that live in the ocean. They drift on currents and provide food for many ocean residents.
“A larger temperature difference between two water layers implies less mixing of chemicals between these water layers,” he said. “Global warming of the surface layers of the oceans, owing to climate change, strengthens the stratification and thereby reduces the upward mixing of nutrients.”
Scientists had believed phytoplankton, which survives best at depths of about 100 metres, is largely stable and immune from the impact of global warming. “This model prediction was rather unexpected,” Professor Huisman said.
“Reduced stability of the plankton, caused by global warming of the oceans, may result in a decline of oceanic production and reduced sequestration of the greenhouse gas carbon dioxide into the oceans.”
Phytoplankton therefore acts as a carbon “sink” which takes carbon dioxide from the atmosphere and deposits the carbon in long-term stores that can remain undisturbed for thousands of years. If the growth of phytoplankton is interrupted by global warming, this ability to act as a buffer against global warming is also affected - leading to a much-feared positive feedback.
Source: Independent News and Media Limited