Climate Changes To Winds Diminishes Antarctic Krill And Plankton
In a paper just published this week in Nature by a Rutgers University team it is reported that changes in Antarctic wind patterns tied to global climate change are producing effects that reverberate up and down the food chain, affecting everything from the tiniest, single-cell phytoplankton to the great whales. Dang it this could mean no more Happy Feet.
(The paper that inspired this post has some dire news … But don’t despair help and positively ‘Happy Feet’ good news is on the way. I am working to help restore and revive ocean pastures around the world by replenishing the dust we humans are denying those oceans. Read more at the end of this post or here….)
OK here’s the news from Antarctica.
A vital boost to Antarctic ocean pasture productivity comes from the mineral nutrients, the dust, that accumulates on the ice over the 9 months of winter. When the ice melts dust and the iron from cold storage is released and stimulates spectacular plankton blooms. Naturally all the rest of the ocean pasture food web, especially the krill, feast on this pasture filled with summers abundance.
The Rutgers authors, Saba and Schofield, are members of the Palmer Long-Term Ecological Research program, PAL-LTER. The program conducts annual shipboard surveys along the western side of the Antarctic Peninsula, including the coastal ocean near Palmer Station, one of the three U.S. research stations in Antarctica.
They describe how their long-term study covering 21 years of data shows that wind and sea ice cover strongly influence how many krill there are at the bottom of the food chain off the Antarctic Peninsula. “The fate of the krill reverberates throughout the food chain”, Grace Saba says.
“The more we understand how the physical environment is tied to the food web, the better we will understand how long-term changes in climate will impact the ecosystem,” Saba says.
The principal tack of Saba’s study is the belt of low pressure, experienced as westerly winds, that bear upon the Antarctic continent. The belt, called the Southern Annular Mode or Antarctic Oscillation, moves north and south on a four- to six-year cycle. It is a powerful force influencing wind and sea ice cover. When the sea ice remains concentrated its vital mineral rich dust and especially the iron therein will support and sustain prolific plankton blooms. When the ice spreads thin or is blow far and wide the vital iron likewise produces a less concentrated blooming.
“There’s a domino effect: changes in large-scale patterns, changes in wind and sea ice, and then changes in phytoplankton, at the bottom of the web,” says Saba, an assistant research professor in School of Environmental Science’s Institute of Marine and Coastal Sciences.
Phytoplankton are the grass of Antarctic ocean pastures and upon that ocean grass depends all of the “wildlife” that share the pasture. The carrying capacity for any pasture whether at sea or on land has always been know to be a measure of the life the pasture will support. Walt Whitman, the famous writer, once said, “All beef is grass.” Indeed that is so as is the fact that, ‘all krill and fish and whales are ocean pasture grass, the phytoplankton.’
It’s time to watch that Happy Feet movie again, antarctic ocean pasture ecology with a smile!
Especially important within antarctic ocean pastures are the krill. These tiny crustaceans thrive on the normally prolific Antarctic blooms under the midnight sun and in turn sustain many species, including fish, penguins, and whales. When the Southern Annular Wind Mode is negative (high pressure over the Antarctic, low pressure over mid-latitudes), cold southerly winds blow across the peninsula, sea ice cover increases, captures and store more dust.
When that ice melts ocean pasture phytoplankton crops bloom in greatest abundance. This leads to higher krill recruitment – the addition of new, young individuals into the krill population – according to Saba’s research. In contrast, during a positive phase of the Southern Annular Wind Mode, there is less ice, less dust stored for the summer blooms, which leads to depressed pasture phytoplankton and lower krill recruitment. That means less food for all other animals up the food chain.
Other newly published scientific reports tell of the vital role of whales and other ocean life that eat the iron rich red Antarctic krill and thus recycle vital iron and other nutrients back to their ocean pastures via their poop. You can read all about how climate change is just a pile of whale poop here.
“Krill live five to seven years,” Saba says. “Their evolution (biology) could be tied to cycles in the Southern Annular Mode. If they have a good year, that’s great. But if they miss even one cycle, that could be catastrophic to their population.”
This clearly shows how the nature of ocean pastures ought not to be modeled as if it is a simple test tube filled with simple ingredients. They are complex sub-set ecosystems, even societies, of life where subtle changes frequently produce profound long-term changes to the larger ocean ecosystems of which they are a part.
In the case of krill whose daily ‘dial” migration from the brightly lit ocean surface pasture to dark of the ocean deep greatly has a key role in the distribution and recycling of vital ocean nutrients especially the vital iron that is in the shortest supply of all. A little less sea ice iron one year may lead to years of depleted krill populations and a collapse of a vast ecosystem.
Saba’s co-authors include her husband, Vincent Saba, a scientist with the National Marine Fisheries Service, and Oscar Schofield, a Rutgers professor of marine science. The research program at Palmer Station, funded by the National Science Foundation, was established more than two decades ago to study changes and processes that couldn’t be captured in a single expedition or research cruise.
Restoring and reviving Antarctic ocean pastures by replenishing vital iron bearing rock dust will sustain this vital ecosystem.
What’s in our plans is repeating our successful work in the NE Pacific to restore and revive dying ocean pastures around the world. From our direct experience in both Pacific, Atlantic, and Indian oceans we know it works, we think just about everywhere. Within just a few years time, revived populations of ocean fish now dwindling, will be brought back, by our efforts, to historic levels of abundance.
We are determined to produce billions of additional fish that will make it into the nets and onto the plates of people around the world. We know that will happen as our experience in the North Pacific in 2012 resulted in more than 60 million servings of our healthy wild Pacific salmon that are right now being provided to hungry American kids who receive food aid from the US Department of Agriculture.
And as a bonus since the ocean pastures we restore and the abundance of fish we grow are carbon based life this all takes place through the repurposing of billions of tonnes of CO2 from it’s harmful form in the ocean into life itself. What could be better than that. The world’s most delicious solution to climate change.