Life on the Line: Scientists track effects of a changing ocean on tiny sea life off coast

NEWPORT, Ore. – In a cold mist under gray skies the Pacific Ocean heaved against the boat as two scientists from Oregon State University pulled a net full of life from the deep.

It was a July day, but it felt like a day in December.

In the net life swarmed, much of it too small to be seen with the unaided eye. The net held the keys to help scientists unlock how creatures of the sea are affected by changing ocean conditions and those effects on the aquatic food chain. And more specifically, the effects to salmon, a fish of much importance to humans.

For 20 years, led by the National Oceanic and Atmospheric Administration's fisheries laboratory in Newport, scientists have made bi-monthly trips on what is called the Newport Hydrographic Line, which takes them to the same seven sampling stations along a 25-mile path perpendicular to the coast. The stations are physical points on a map. There are no buoys or other structures that mark their locations. The scientists find them using GPS.

They launch their research vessel, the R/V Elakha, from a dock in Yaquina Bay that sits along a jagged bulge of land on which OSU’s Hatfield Marine Science Center resides. The trips have amassed an extraordinary amount of data about the sea and the life within it. The data is routinely posted on NOAA’s Northwest Fisheries Science Center website and is used primarily to help forecast salmon runs. But the data has also told the story of changing ocean conditions and its impact on the food chain.

“We can also look at the changes in the bioenergetics of the food chain across the whole 20-year time series,” says OSU research assistant Jennifer Fisher. “It doesn’t just relate to salmon; it relates to sardines and (other) fish. It gives us an idea of ocean acidification, toxic algae – lots of things.”

Fisher has been going on these trips to sea for five years aboard the 54-foot research vessel owned and operated by OSU.

On this day, Fisher, OSU lab technician Tom Murphy and deckhand Dave Weaver use two different cone-shaped nets to capture organisms that live in the sea and that form the basis of the oceanic food chain.

Fisher’s primary interest in the day’s catch is in a tiny crustacean called a copepod. These creatures feed on the sea’s phytoplankton. Copepods are animals with large antennae and are only a millimeter or two in length. Under a microscope their bodies are an elongated oval protected by an exoskeleton. But they are nearly transparent. And inside their bodies scientists have discovered a lipid sac, or stored fat.

Bill Peterson, an oceanographer with NOAA Fisheries who’s in charge of the Elakha trips, described copepods as like “little bears.”

“They put on the fat and then they go live down deep in the ocean (during the winter),” he says.

They live off that fat during the winter months when there is less sun and, therefore, less phytoplankton -- those engines of photosynthesis that produce energy from sunlight. But in the summer there is more sunlight and, therefore, more phytoplankton. The copepods then rise to feed.

The copepods have their own predators: forage fish.

Everything about sea life is connected. The currents, the winds, atmospheric pressure, water temperature, salinity, and even the spin of the planet, affect life at sea.

All this complex interaction that scientists are continually monitoring, sampling, and analyzing, affects the health of the copepods, or as Fisher says, their bioenergetics, which is “more related to the quality of the copepods as food for other fish. So the fat content.”

And so the forage fish like a fat copepod. And the salmon, after being born in freshwater streams and make their way to the ocean, look for food, and forage fish can make a good meal. And it’s not just salmon that are looking for a high-fat-content food chain, but other sea creatures too, like sardines and whales.

Brown Goo

On the deck of the Elakha, Weaver operates a winch, dropping the semitransparent white cone-shaped vertical net into the water off the stern of the boat. Fisher gives him direction on how far down to go. Weaver watches the digital readout on the winch, stopping when it reaches its mark. Then he reverses the process; the winch grinds and whirs and the net reappears from the murky sea.

But it is no longer white. It is covered in a goopy brown mess. The goo is phytoplankton. It is such a large amount that Fisher makes a point to point it out. Later she comments on how murky the water was and how much phytoplankton was in it.

“The most I’ve seen in my five years of working here,” she says.

As the net still hangs over the stern of the boat Murphy sprays it down with a hose. The purpose is to get all the tiny animals, including the copepods, caught in the mesh of the net down to the bottom into what is called the cod end, a cylindrical attachment. Then he runs those contents through a sieve to remove the water; the creatures that remain are placed into a jar for later analysis.

The phytoplankton bloom is of interest to the scientists. Such blooms are caused by a process known as coastal upwelling, where colder water from deeper regions of the ocean is brought to the surface, bringing with it nutrients – nutrients on which phytoplankton thrive.

Scientists say the upwelling is caused by the wind and the spinning of the earth. Winds from the north push the surface water south. At the same time the earth’s rotation moves water away from the western shore. The colder water from below then takes its place.

But there are also other processes at work that scientists measure as the Pacific Decadal Oscillation. The PDO climate index looks at the variations of the surface temperature of the ocean. There are two phases – a warm and a cold, mostly linked to the strength of Aleutian low pressure in the Gulf of Alaska during the winter months.

Scientists have been keeping track of these phases since the early 1900s and have watched as they have oscillated between warm and cold. A phase could last 20 years. Then, like someone throwing a light switch, it swings the other way. But a mysterious phenomenon has been observed since just before the turn of the century: the oscillation between phases has significantly sped up.

Since about 1998 the shift between phases has occurred roughly every five years instead of every 20 years. Scientists are still trying to figure out why.

But what has been well established is that during cold phases salmon returns are high; in contrast, they are low during the warm ones.

And going back to the copepods – those tiny sea creatures by the billions – they are also influenced by the PDO. The phase of the PDO determines what kinds of copepods arrive off the shores of Oregon, driven by the currents.

“The warm PDO is small, tropical copepods, and the cold PDO is the big, fat copepods from the north,” explains Peterson.

Again, it’s those lipid-rich copepods driven to Oregon from the Gulf of Alaska that have evolved a way to make it through the winter. They help make a fat food chain. Copepods from the south, the tropical copepods, create a less lipid-rich food chain.

In 2014 and 2015, “The Blob,” a warm mass of water, formed in the Pacific Ocean off the coasts of Oregon and Washington. Scientists on the Newport Line found that it brought tropical life or subtropical life to the Northwest ocean waters, leaving the food chain lacking in the fat content many species (including salmon) that migrate to the area are looking for.

A tough job with little security

Between sampling stations, as the Elakha captained by Paul Tate races farther out to sea, the scientists huddle in the warm cabin. Amid the swaying of the boat they try and catch a few moments rest. The rain on this day, while not driving, is a cold and constant companion. It’s enough to make things unpleasant.

The day sinks into night, and the gray sea turns black. Only the whitecaps illuminated by the boat’s lights can be seen. They crash against the boat and sometimes white spray explodes over the side and onto the deck. Beyond the boat all is dark, save for a single light from some far off ship or fishing vessel. On this night, there is no such thing as a horizon.

The Elakha slows, and the crew stirs. They make their way back onto the swaying deck to again cast their nets in the name of science. It is exhausting work, made worse by the cold, the rain and the constant rocking of the boat. The smallest task takes on a new and higher level of effort. Seasickness is common.

On this day, after hours at sea, and as the night becomes wetter and colder, the scientists decide they have had enough, and the Elakha turns around and heads back to shore. They made it to five out of the seven stations – about 15 miles from shore. Long before the scientists decided to return to base, the reporter on this journey had succumbed to the rigors of seafaring, stricken by seasickness and dehydration, becoming mostly useless.

Back on land, the scientists haul the samples to a lab inside the Hatfield Marine Science Center. Even after an exhausting trip, Fisher’s work is not yet finished. She needs to collect 20 female copepods from the samples for later study.

She places a petri dish full of sea life beneath a microscope and searches for the copepods among the other microscopic life, including a crab larva, which through the microscope looks much like an adult crab but helpless as one copepod appears to attack it. Fisher uses an eyedropper to isolate the copepods and, one at a time, plucks them out of the dish and places them into separate jars.

Later she says most of the female copepods had laid eggs. She says studying their egg production will help scientists understand how changing ocean conditions can alter their biological functions.

“It’s giving you the idea of the bioenergetics of the copepods,” she says.

At one point as she peers into her microscope, Fisher gives a sudden start. She sees what she thinks is Pseudo-nitzschia, an algae that can produce toxins harmful to humans, marine mammals and fish. A bloom caused by the algae forced the closure of Dungeness crab fishing off the coast of Washington last year and the shutting down of harvesting of other shellfish off Oregon's coast.

She needs to have a colleague confirm what she’s seeing. A few days later, she says it was in fact Pseudo-nitzschia. But the good news is there were other species of plankton present in the samples, “so it’s not necessarily a cause for concern,” she says.

But she and other scientists will continue to monitor the seawater and if the harmful algae become the dominant species of plankton and are high in numbers, they will alert the Oregon Department of Fish and Wildlife.

It is all just part of the job – a job Fisher says has little security. The funding for what she does is unstable and there’s no guarantee for the future.

Peterson says to properly do the research, he needs about $500,000 a year, but right now he’s only getting about a quarter of that. There are a number of reasons the funding has decreased and part of that reason is what he calls a “stingy Congress.”

“We’re very much depending on what’s called soft money, where you have to write proposals, and we’ve done well, we really have, I can’t complain about the proposal writing,” he says. But he adds it does get tiring.

The last three years have been hard, he says, but they’re making do.

For Fisher, while her job may not be secure, she says there is an upside: she has more control over what she does.

“You write proposals, you get the grants, get funded, you get to do that research,” she says.