Arctic food chain hit as tipping point passed

[OKIsItJustMe]

https://www.ed.ac.uk/news/arctic-food-chain-hit-as-tipping-point-passed

An irreversible shift in the chemical make-up of the Arctic Ocean driven by climate change is disrupting the region’s food chain, a study suggests.

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Key nutrient
Nitrate is vital for the growth of plankton at the base of the Arctic food chain, and reduced levels of the nutrient limit the amount of life the ecosystem can support, the team says.

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Ice losses
Their analysis reveals a clear shift from 2009 onwards, with nitrate levels in waters leaving the Arctic falling steadily. The drop in nitrate levels coincided with a drastic reduction in Arctic sea ice that began around the same time, the team says.

The extensive loss of sea ice ramped up a process that converts nitrate to nitrogen gas – called benthic denitrification – in shallow continental shelves that underly nearly half of the Arctic Ocean, the team says.

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Since the change in nutrient conditions is driven by ongoing sea ice loss, it is very unlikely the Arctic Ocean will ever revert to its previous state, researchers say.

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Santos-García, M., Ganeshram, R.S., Oziel, L. et al. Sea ice loss drives a regime shift in Arctic Ocean nitrogen biogeochemistry. Commun Earth Environ 7, 442 (2026). https://doi.org/10.1038/s43247-026-03569-x

[cbabe]

1. Plankton equals oxygen.

NOAA's National Ocean Service
https://oceanservice.noaa.gov › facts › ocean-oxygen.html

How much oxygen comes from the ocean?

At least half of the oxygen produced on Earth comes from the ocean, mostly from tiny photosynthesizing plankton. But marine life also uses roughly the same …

[OKIsItJustMe]

2. Plankton equals life

https://www.noaa.gov/education/resource-collections/marine-life/aquatic-food-webs

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Aquatic food webs show how plants and animals are connected through feeding relationships. Tiny plants and algae get eaten by small animals, which in turn are eaten by larger animals, like fish and birds. Humans consume plants and animals from across the aquatic food web. Understanding these dynamic predator-prey relationships is key to supporting fish populations and maintaining healthy ecosystems so that we can all enjoy sustainable food supplies and a healthy environment.
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https://education.nationalgeographic.org/resource/marine-food-chain/
https://www.whoi.edu/ocean-learning-hub/ocean-topics/ocean-life/ocean-plants/phytoplankton/

[2naSalit]

3. Also...

Possibly the reason Pacific Gray Whales are starving?

[OKIsItJustMe]

4. Remove the bottom of the food web, and the top will certainly suffer

https://marinepatch.com/what-do-gray-whales-eat/

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What Do Gray Whales Actually Eat?

Although gray whales eat very little whilst on their long migration, they may come across and eat schooling squid, krill, crab larvae, ghost shrimp, plankton, and small fish.

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How Do Gray Whales Catch Their Food?

Gray whales are baleen whales which means they have plates of whalebone on each side of their upper jaw that they use as a filter to extract food.

These whales are some of the only whales that consistently feed off the bottom of the ocean.

They use their baleen and roll on their side to suck up sediment which will catch plankton, larvae, small fish, tube worms, and anything else that is down there.

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