Balance of nature: importance of ocean ecosystems (Introduction)

by David Turell , Friday, October 18, 2019, 19:57 (1645 days ago) @ David Turell

Krill play a major role in the carbon cycle and supplying protein fertilization of the ocean floor:

https://phys.org/news/2019-10-whale-food-krill-carbon-dioxide.html

Antarctic krill are well-known for their role at the base of the Southern Ocean food web, where they're food for marine predators such as seals, penguins and whales.

Less well-known is their importance to the ocean's carbon sink, where CO2 is removed from the atmosphere during photosynthesis by phytoplankton and sequestered to the seafloor through a range of processes.

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"By eating phytoplankton and excreting carbon and nutrient-rich pellets that sink to the seafloor, Antarctic krill are an integral part of the carbon cycle and a key contributor of iron and other nutrients that fertilize the ocean," Dr. Cavan said.

"Krill fecal pellets constitute the majority of sinking carbon particles that scientists have identified in both shallow and deep waters in the Southern Ocean.

"Antarctic krill grow up to 6-centimeters long and weigh around one gram, but they swarm in such vast numbers that their combined contribution to the movement of ocean carbon and other nutrients can be huge.

"The Southern Ocean is one of the largest carbon sinks globally, so krill have an important influence on atmospheric carbon levels and therefore the global climate."

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But there is no consensus on the effect that harvesting Antarctic krill could have on atmospheric carbon and ocean chemistry nor, for that matter, how growing whale populations might also affect krill numbers.

"Southern Ocean ecosystems and chemical processes are highly complex and poorly understood, and our lack of knowledge about the extent of krill's ability to affect the carbon cycle is a concern, given that it is the region's largest fishery.

"We don't know, for example, whether a decline in krill might actually lead to an increase in the biomass of phytoplankton, which are also integral in transporting carbon to the seafloor.

Comment: another example of the importance of ecosystems and how tightly controlled they are and must not be disturbed by humans. But we humans are put in charge and must be careful in how we manage these systems. These had to be set up before H. sapiens arrived with the ability to learn to handle them. Yet dhw wants God to rush to create humans.