Phytoplankton–an abstract word for a simple concept. Plainly put, phytoplankton are the wide variety of plant-like organisms that make up the very bottom rung of the oceans’ ecological ladder. Unfortunately for the oceans (and for us), a significant part of the population have died–over 20% within the past 60 years, in fact. Moreover, current theories predict that phytoplankton levels will only continue to drop at greater rates.
According to a study published by the American Geophysical Union, phytoplankton levels in the Indian Ocean have decreased by nearly 20% in the last 6 decades. Most scientists attribute this decline to a warming of ocean surface waters, resulting in an interruption of the ocean’s mixing. Dark, nutrient-rich layers of water drift upwards into the sunny, phytoplankton-rich regions near to the ocean’s surface.
If this cycle is disturbed, phytoplankton are deprived of the much-needed nutrients that these multi-layered currents provide. The study coauthor Raghu Murtugudde, an oceanographer at the University of Maryland in College Park, believes that this foretells the long-lasting effects that are guaranteed to ripple upwards throughout the food chain.
“If you reduce the bottom of the food chain, it’s going to cascade,” said Murtugudde. “The phytoplankton decline may be partially responsible for a 50 to 90 percent decline in tuna catch rates over the last half-century in the Indian Ocean. This is a wake-up call to look [to see] if similar things are happening elsewhere.”
One RAHS junior, Joshua Buenbrazo, had concerns similar to Murtugudde’s, especially for the potential impact something like this would have on Seattle.
“When hearing about this, especially the huge impact on the Indian Ocean, I’m kinda shocked that we don’t know if it’s happening in the Pacific too,” said Buenbrazo. “If global warming is having such a strong impact on the Indian Ocean, how do we know it’s not being just as damaging to the Pacific? Seattle is a port city, and lot of our industry is reliant on the ocean.”
Washington as a whole generates nearly $4.5 billion annually from fishing, hunting, and wildlife watchers, according to the Washington Dept. of Fish and Wildlife. The entire Pacific Northwest is highly reliant on the ocean for a large part of its economic revenue, and while the study only covered planktonic blooms in the Indian Ocean, warming surface waters affect the entire planet.
In 2013, Nicholas Bond, a climatologist working at the University of Washington, detected an unusually warm body of ocean surface off the Pacific Northwest. Named “The Blob,” it grew to over 1,000 miles in length and was responsible for an enormous disruption in the ecology of the western coast of the United States. Nearly 5 degrees (fahrenheit) warmer than normal seasonal waters, The Blob was a nutrient-poor section of the North Pacific Ocean, situated just off the coast of the pacific northwest. The Blob persisted late into 2015 before just sort of disappearing, and its effects are still rippling throughout Washington and the Pacific Northwest.
According to Nate Mantua, leader of the Landscape Ecology Team at the NOAA Southwest Fisheries Science Center in Santa Cruz, The Blob’s effect on the Pacific Northwest’s ecosystem is likely to persist.
“All the indications are that ocean temperatures and marine food webs within 20 to 50 miles of the coast are going to continue to be warm and unusual,” said Mantua.
The unusual series of environmental disturbances caused by The Blob have disrupted seasonal temperatures, resulting in warm winters for the past few years, and has even upset coastal wildlife enough to cause them to emigrate hundreds of miles north of their usual habitats.
“Tropical and subtropical creatures are likely to continue to be found along the Pacific Coast for the next few months at least into spring,” Mantua said.
While no official investigation into The Blob’s effect on the planktonic levels of the pacific has been conducted as of yet, the new study on the Indian Ocean has strongly indicated that a disruption in ocean surface temperatures – especially warming – has a direct negative effect on the growth of phytoplankton.
It is, then, no stretch of the imagination to consider that the recent rise in ocean temperatures worldwide, along with the overstay of The Blob from 2013-2015, has had a similarly negative effect on the marine ecology of the Pacific Northwest. The directly visible impact that The Blob had on the Pacific Northwest begs the question of what invisible consequences it left behind, especially now that we know how drastically ocean temperature affects the development of phytoplankton.
“I feel like this is very concerning, because the marine sector of the world is vital to the earth. Learning that major parts of the ecological chain are deteriorating is scary,” said Buenbrazo. “If a trend like this keeps occurring, everyone in the world will feel the negative effects of it.”
Unfortunately, the full effects of The Blob, and the continuing effects of the global rise in ocean temperatures, may take years, or even decades to be completely realized, as the effects ripple their way up through the food chain.