Settling the Southern Pacific Gyre

30 June 2063, Huang Marine Research, Marcelli Rise

Oliana paced around her room at the Huang guesthouse, restless. She paused in front of the full length mirror. She looked at her reflection and said, “What are you doing here?” I have no idea! Her eyes scanned those classic Polynesian features – thick dark hair framing a round golden-skinned face, almond-shaped black eyes – all gifts from her mother. Mom, is this what you went through twenty years ago, when you married dad and moved to Auckland?

 She resumed pacing.

Her father had been understanding all through lunch, letting her pour out her unhappiness. At the end, he told her with a sigh that they would work through this change together, as a family. Although she had responded with an unbelieving glare, in her heart she knew he was right. Months ago, they had all crossed an invisible line. This was the future, whether she liked it or not. Later today mom will be here, with little Adam. Can’t wait to have them near again.

She stared out the window at the underwater seascape. The guesthouse window looked out on the same platforms she had seen from the observation dome yesterday. She stared at the waving forest of kelp and the many, many creatures. A grey seal stared back at her.

She looked down and saw one of those blue-eyed scallops begin to clap their shells and puff along the sand. It reminded her of that boy, what was his name? Pietro? Yeah. What kind of name is that? But he was sweet, despite my rudeness. He seems to love his life on the Rise. Maybe there is something good here.

“Manaia, I’m curious.”

“Yes, Oliana,” came a female voice from the air, with a light New Zealand accent. It was their family’s Augmented Intelligence Agent, Manaia.

“Tell me about this place, the Southern Pacific Pelagic Territory.”

“What do you want to know?”

“Hmm, start with some of the basics.”

“Yes, Oliana.  The South Pacific Pelagic Territory is the ocean region between Australia and South America. contained within the Southern Pacific Circulation Gyre.” A map took shape on the display screen just to the left of the window.

“This gyre is a massive ocean current, perpetually circulating in an anti-clockwise motion between these two continents.”

“Well, why did the people in the Rise choose to settle here rather than another part of the ocean?”

“There are many reasons. For one thing, the weather is calmer.” A world map of the world’s oceans appeared.

“This map displays storm tracks from the last ten years, those light blue, yellow and red lines in the northern latitudes, and in the southern Indian Ocean, and above Australia and New Zealand. These are places with frequent cyclones, hurricanes, and typhoons; incredibly rough conditions to live in, if you’re floating on top of the sea.”

“In contrast, see the dark blue expanses in the southern Atlantic ocean, east of South America and also in the southern Pacific ocean, west of South America. Those are area where these kind of storms are almost non-existent.”

“Okay, that makes sense. No one would choose to live in the paths of hurricanes. What else could motivate people to settle out in the middle of nowhere, like here on Marcelli Rise?”

“Marcelli Rise is like an oasis in the midst of an ocean desert.”

“An oasis?! Looks like there is plenty of water all around.”

“Yes, lots of water. However, there is not much sea life in that water. On land, desert nomads gather at oases because of shelter and easy access to food – often other life attracted to that fresh water source. The open ocean is like a vast blue desert; sprinkled throughout this marine desert are hundreds of submerged mountain chains, seamounts like the one beneath Marcelli Rise. Parts of these mountain chains reach up into the light zone of the sea – the uppermost 200 metres. Nutrient-rich waters can travel up the sides of these seamounts into sunlit regions, producing plankton blooms like off of South America. It is another kind of upwelling. These conditions allow settlers to cultivate rich sea farms around seamounts.”

“Ah, so they can make a living exporting the seafood they grow from the ‘oasis’ of these underwater mountains.”

“That’s right. On this mountain range – the Louisville submarine ridge – there are already twenty-three settlements of sea farmers, like the settlement here in Marcelli Rise. This ridge extends 1400 kilometres eastward into the Pacific.”

“Wow, that’s huge. And room for much more growth. I wouldn’t have guessed that this could be ‘somewhere’ for so many people. Pietro said something about twinned cities?”

“A few Pelagic settlements were intentionally established off the coast, beyond the EEZ, of major cities on the continents, such as Sydney, Auckland, Jakarta, Taipei, Lima, Santiago, Tierra del Fuego. These grew and became important hubs that facilitate economic, social, cultural and political ties with the major cities they are near, or ‘twinned with’, around the South Pacific Rim. These hubs benefit both Pelagic and terrestrial nations greatly.”

“Thanks, Manaia. I’d like to look at the Pelagic Territory again and this twinned city system?”

The map of the Southern Pacific Pelagic Territory appeared with the Pelagic urban settlements and their terrestrial twinned cities.

“Pietro also mentioned that some seasteaders are nomadic. Can you show me those?”

“Yes, adding them to the map now, along with their routes over the last week so you can get an idea of how they travel.”

Green icons appeared. “One hundred and seventy-four nomadic communities traverse the Southern Pacific Pelagic Territory, in every part of the gyre. Many of them ranch commercially important marine species like southern tuna.”

“Wow, this is a busy Territory.” Oliana studied the map on the display.

“Manaia, if most of the open sea is essentially a desert, where do these nomadic communities find food for their schools of fish?”

“Excellent question, Oliana. Good deductive reasoning, I will note this in your coursework.”

The display changed, showing the ocean off the west coast of South America, from Cape Horn up along the coastlines of Chile and Peru.

“This is the Humboldt Current it travels northwards along the coast, as you see.” The current flowed up the map, sweeping in from the Antarctic in the south then bending to parallel the equator in the north.

“The west coasts of continents are some of the most productive regions of the sea. Even though these coastal areas represent only 1% of the ocean’s surface, they produce about 50% of the world’s fish catch, due to the special dynamics caused by coastal currents, like the Humboldt Current. It is referred to as upwelling.” The display shifted to an upwelling model.

“It looks like dark blue water is coming from deep under, turning up near the coast for some reason, maybe because of the wind? Explain the diagram, please.”

“Of course, Oliana. As a prevailing wind travels north parallel to the coast…”

Oliana interrupted, “Prevailing?”

“Yes, surface wind that blows predominantly from the same direction. In this case, what direction is the prevailing wind affecting the west coast of South America?”

“It looks like it is coming from the south, so it’s blowing northward?”

“Yes, and as it consistently blows northward, it causes the water next to the shore to also move northward, This creates the Humboldt Current. However, that’s not all. As the current travels along the shoreline, the force of the earth’s rotation…”

Oliana burst in, “I know that one, the Coriolis effect!”

“Right you are. The force of the Coriolis effect pulls the surface waters away from the land, westward. As this happens, other waters rise from the depths to replace the surface water that is being pulled out towards the open sea. These deep waters happen to be very nutrient-rich. This process is referred to as Ekman transport.”

“Note that please, I want to learn more about this. That’s a funny name, Ekman transport.”

“Ekman, refers to the clever scientist who recognised the pattern.  Someday you too might have a phenomenon named for you! The important result, Oliana, is that nutrients are pulled up into what would otherwise be a desert-like sea. Because of the nutrients from the depths, phytoplankton bloom. And, we already went over this last week, who likes to eat phytoplankton?”

“Well, phytoplankton are like the first links in the huge food web of the sea.”

“That’s right, Oliana. So can you guess where the tuna ranchers can find food for their schools? What do tuna like to eat?”

“I guess they’d eat the smaller fish that are feeding on the phytoplankton.”

“Yes, in this case it is huge schools of anchovies, which the tuna of the nomadic communities feed on when they are in this part of the Pelagic Territory.”

Oliana was silent as she processed the information… “Okay, I think I have that. Manaia, could you please create review modules on the Coriolis effect, Eckman Transport, Upwelling, South Pacific Gyre and marine food chains for next week? And also, a recap of the history of the South Pacific Pelagic Territory.”

“Yes, I have placed them in your coursework schedule.”

“Thanks, Manaia, this will help me understand this new world.” And I will be able to have an intelligent conversation next time I meet that Pietro.

The display reverted to the map of the Pelagic settlements and nomadic communities, now with the currents swirling the Southern Pacific Gyre. Oliana traced her finger on the glass surface, following several of the nomadic sea ranchers.

“So, I see how they are migrating near the Humboldt Current to feed the tuna… Can you show me an overlay of ocean productivity for the Southern Pacific?”

“Excellent request, Oliana. I’ll show you concentrations from the last month of chlorophyll A, the pigment in phytoplankton which is critical in converting sunlight to energy. Its presence detected in the satellite scan correlates with areas of ocean productivity. What observations can you make?”

“Well, I can see the yellowish and reddish areas, where there are high concentrations of phytoplankton off the west coast of South America. I also see the productive waters are pulled into the Southern Equatorial Current for a long way westward.”

“Very good. What else?”

“Many of those nomadic communities travel into the blue and deep blue areas of low productivity. These must be the blue deserts you mentioned.”


“So, why would they go there? How can they feed their tuna in the deserts?”

“Excellent question. Well done.”

Oliana flushed with pleasure.

“In the surface layer of water, down to 200 metres, nutrients from the deep are not available, and so there is little life. However, in the next layer of water, from two hundred to a thousand meters,  the conditions are just right to support many species, including large schools of bristlemouth, one of the most abundant vertebrates on the planet. Tuna can feed to depths of almost a thousand meters, so this rich pastureland of what is called the twilight zone is accessible to them.”

“These nomadic farmers sure know their stuff! That’s how they can feed their stocks. But what do the bristlemouth eat, then?

“Another excellent question, Oliana, but one we will have to answer another day. It seems that your father is looking for you. Time to go to the airport to fetch your mother and Adam.”

Oliana sighed. “Just when it was really getting interesting.” She began collecting her things, then stopped.

“Manaia, how far will our new seastead be from the seastead of Pietro’s family?”

“Theirs is plot 23, the one your father has registered for is plot 39. That means they will be about seven kilometres from you.”

Oliana smiled, “Good to know. Thanks.” She rushed out the door to meet her father.

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