Forage Fish and Salmon Survey
August 16 - September 26

September 30: From sea to office

Sitting in my office at the University of Washington (swaying gently), I think about highlights from the 2010 BASIS and high-resolution surveys. In this blog I have shared a few of the many exciting, unexpected, or day-to-day moments from the Bering Sea.

On August 19 I mentioned that age-0 walleye pollock and Pacific cod distributions were different than we had expected, but during leg 2, some familiar patterns emerged. These data will contribute to a better understanding of the distribution/abundance of forage fish and salmon species in the Bering Sea. This was a formidable group effort.

Thanks for sharing in this adventure. Best regards, Sandy.

September 26: A successful survey

We're done. The high-resolution survey completed 60 stations in nine days, plus a full day of acoustics. All members of the science party (Ellen, Jen, Bruce, Oleg, Natalia, Alex, Kevin, Rosa, Brenna, Liz, and Luke) share credit for pulling together and making this such a successful trip! Thanks also to the crew on the NOAA ship Oscar Dyson for their support.

On our way back to Dutch Harbor yesterday, we travelled south along the 167 deg W line with 35+ knot winds at our back. From the back deck we could watch swells greater than 20' pushing us along (Right). (Photo: Jen Nomura, UW)

Now it's time to take our data (in triplicate, for safe keeping) back to the lab and begin our analysis. We've also shipped back our frozen specimens, including ones for Ballard, Everett, and Winlock High Schools. After six weeks at sea, I'm ready to transition back to land. Back to top

September 24: Home stretch

After today, we've got just one more day of trawl operations. Tomorrow we'll collect acoustic data back down the 167 deg W line, and will do a few casts with the CTD (Conductivity-Temperature-Depth) to see if things have changed since we were here a week ago.

Left: The deck crew hard at work. (Jen Nomura, UW)

Over the deeper water (>100 m), we had a reprieve from jellyfish but now we're back in the thick (and slimy) of things. In one nighttime midwater trawl (with the top of the net at 25 m), we collected 600 lbs of jellyfish in only 7 minutes.

No more deep age-0 walleye pollock for us. We're now finding small schools, along with age-0 Pacific cod, in the warm surface waters. Finally to the crux of our question –- why choose to be down deep when you can be near the surface?

A raptor ... at sea?

Our excitement today was the appearance of a Peregrine falcon around the boat. With 30+ kt winds the bird swooped and dove, making our usual entourage of seabirds nervous. Those of us on the bridge got to see the falcon land on a railing right outside the window –- with a distance of only 5 feet (and a pane of glass) separating us. Back to top

September 20: High resolution, high octane

Having completed stations along the 167 deg W line of longitude, we've moved to 166 deg W. Weather, limited daylight, and the amount of sampling have slowed us, so we're adapting our survey plan to maximize the time we have left.

On September 10 I posted an echogram of age-0 pollock schools, but those were small compared to what we encountered yesterday. We collected acoustic data on aggregations that were >50 m (110 ft) high and extended for more than 6 km (3.7 miles)! Midwater trawls were 99.9-100% age-0 pollock. (Photo: Luke DeCicco, USFWS)

Looking for patterns

We're surveying across regions with different oceanographic characteristics (temperature, salinity, etc) to look for patterns in age-0 pollock distribution.

We've noticed that deep water schools seem to appear and disappear abruptly (above). By sampling the oceanography and fish every 15 nautical miles, we'll look at why these patterns exist. As we work our way up the 166 deg W line we'll see if the pattern holds. See larger image (Echogram: Jennifer Nomura, UW)

Four more days of sampling with a lot of ground to cover -– given the frequency of our sampling, we're earning the "high-octane" nickname. Back to top

September 19: Oceanography 101

Through the University of Washington Educational Outreach's UW in the High School program, we've partnered with three Washington State high schools -– Ballard High School (Seattle), Everett High School (Everett), and Winlock High School (Winlock) -- in "Oceanography 101" classes. Here, we'll share data, specimens, and experiences from our research.

Q&A with Ballard High School (Hi Ballard!)

What is the significance of 30 and 60 m trawl depths?

We do two types of trawls. The surface trawl covers from 0-1 m below the surface to 20-30 m down. The midwater trawl can be placed at any depth –- whether it's 30 m (to see what is below the surface trawl), or at 60 m to see what is deeper.

Is there an increase in jellies? If so, why?

When we added acoustics to the BASIS survey in 2008, we found lots of jellyfish. 2009 was colder than 2008 and had fewer jelliyfish. We predicted that because 2010 was colder still, we would see even fewer jellyfish. We were wrong -- which suggests that other factors besides temperature are important.

Does El Niño affect what you are finding?

Oceanographers observed that 2010 was a very cold year and sea ice left the Bering Sea later in the year. Late ice and cold conditions can affect many things -– for example, if food becomes available to young walleye pollock late, they may not grow as quickly which may affect their survival. Back to top

September 17: Shifting gears

We have finished the Oscar Dyson-based part of the BASIS survey, which totaled 70 oceanographic stations and 89 trawls. We completed all but three of our designated stations, which is pretty good given the unpredictability of Bering Sea weather in late summer.

Moving west, an odd mix of fish

As we moved further west during leg 2 (165-168 deg W), we continued to find juvenile salmon (left), capelin, Pacific herring, jellyfish, and age-0 walleye pollock. We saw fewer Pacific cod and Bering wolffish than we had seen during Leg 1, a fact that has us scratching our heads.

For the next nine days we will observe how oceanographic characteristics like temperature, salinity, and others influence the distribution of age-0 pollock. In 2009, we noticed that in some areas age-0 were close to the surface and in other areas they were down near the bottom.

This survey will help us to answer why the difference exists and whether there is an advantage to being in one place over the other.

Getting ready for a closer look

The high-resolution survey sampling will look much like what we have done during BASIS -- acoustics, midwater trawling, surface trawling, and oceanography –- but stations will be closer together and we'll be sampling fish much more frequently. After looking at a large area during the BASIS sampling, we're ready to zoom in and take a closer look. Back to top

September 13: Unexpected guests

Beyond the science, some pretty interesting things happen at sea. Although land-birds are likely common in your neighborhood, they're an oddity in the middle of the Bering Sea.

This year, we've had a Dark-eyed Junco, Golden-crowned Sparrow, Lapland Longspur, Orange-crowned Warbler, Wilson's Warbler, and Horned Lark appear on board. (photo: Luke DeCicco, USFWS)

These birds may be using the Dyson as a resting place during migration or may have been blown off course by a storm. Some stick around and amuse us for a few days, eating small fish off the deck.

Shark!

On Saturday we caught a salmon shark (left) in a surface trawl, an unsurprising catch given that we were also catching immature salmon. This male shark was 189 cm (76") in length -- much longer than I am tall! (photo: Luke DeCicco)

After taking a quick measurement, the crew slid the struggling shark down the trawl ramp and back into the water. Shark catches during BASIS are rare, so everyone is on hand to watch.

On the survey side of things, we're sampling in the north near Nunivak Island and again catching capelin, sandlance, and herring in the nets. Now we'll begin moving south, and into some nicer weather. Back to top

September 10: Little fish down deep

In the deeper region of our study area (100-150 m), we finally found one of our targets –- age-0 walleye pollock (right).

After a few years, these fish may be captured in the Alaskan walleye pollock fishery, the second largest fishery in the world by volume. Besides their commercial importance, age-0 walleye pollock are also an important prey item for large fish, marine birds, and mammals.

Using a midwater trawl, we sampled the young pollock at depths >80 m. When we set the trawl, we added a sensor (a "third wire") on the top of the net so we could watch what is going in. Watching the third wire display is always exciting, and sometimes cheering results when we capture an intended target.

Left: echogram showing location of age-0 walleye pollock. See larger image

We're saving the age-0 pollock for a project looking at fish energy content as a way to understand whether the young fish will survive their first winter.

We're now heading back to the southern portion of our study region. We expect to find immature salmon and more age-0 walleye pollock. Maybe there will even be more cheering. Back to top

 

September 7: Leg 2 begins

We had a welcomed break in Dutch Harbor. Everyone spent time around town, combing beaches, hiking, and fishing.

On Saturday, the team aboard the F/V Epic Explorer left the dock to begin their portion of the forage fish and salmon survey. The Epic team will do stations along the 170-172 deg W lines of longitude before heading north. After just one station, however, the vessel had to move to St. Paul Island to wait out a storm that has brought high winds and waves.

Eight members of our Oscar Dyson science party headed home and seven new members joined us. Unlike the last leg, everyone got their luggage. The new scientists are finding their way around and are settling in. We just finished tying the gear down in anticipation of moving into the same storm that forced the Epic Explorer into hiding. We're ready to go, regardless of the ride! Destination: 167 deg W. Back to top

September 1: Shallow water, lots of company

We finished the last of our shallow (25-50m deep) stations yesterday and found high numbers of capelin (right) as well as age-0 sandlance and euphausiids/krill (below). With so much great food, we had the company of humpback whales, fin whales, and short-tailed shearwaters throughout the day.

Observers from the US Fish and Wildlife Service noted more than 20 whales and tens of thousands of birds. We knew that we were in a productive place when it took 12×500 mL jars to store the zooplankton from one of the nets.

We are now working our way south along the 166deg and 167deg lines of longitude toward Dutch Harbor. Tomorrow will be our last day of sampling on this leg, ending with deep stations (150-500 m bottom depths).

Deep stations take a while to complete -- CTD and zooplankton sampling nets are towed at the much slower rates of 0.25 to one meter per second -- so we're ready for a long day. Based on nearby sampling, we hope to find immature chum salmon near the surface and age-0 fish (walleye pollock and Pacific cod) in deeper water.

Everyone is smiling at the prospect of spending a few days on land before the next leg of the survey. Back to top

August 29: Strange days, indeed

Survey-wise, 2010 has been very different than expected. Age-0 pollock aren't where we thought they'd be. Age-0 Pacific cod numbers are higher than anticipated. Jellyfish continue to haunt us as we move west. Yellowfin sole and Bering wolffish (below) have been consistently captured in the surface trawl, which is unusual for this survey.

Juvenile salmon catches have also been low, with only one large catch of juvenile sockeye so far. Juvenile chum, which are normally found near the Kuskokwim River, have been virtually absent.

Yep ... still cold

The "cold" classification for this year is unchallenged. This morning, at a 70m depth station, the CTD found 0 deg C water from 20m all the way to the bottom. If you're a fish that doesn't like the cold, 2010 is a tough year. If you're a scientist trying to figure out fish distribution patterns in the Bering Sea, 2010 is also a tough year -- but incredibly interesting.

We're staring at catch maps that are taped to the wall in the acoustics lab, trying to predict what we'll find at the next station. So far, our predictive power has been fairly low, but we are traversing very different regions as we move west. There's still a lot of ground to cover. Back to top

August 25: Sunburns ... and tons of jellies

We have been enjoying sunny and calm days, with beautiful weather for our set near Cape Newenham (right). Several scientists have rare Bering Sea sunburns to prove it. On Sunday we watched in awe as about 10 tons of jellyfish came aboard after a 20 minute surface tow.

Fewer young pollock, more young cod

Catches of age-0 pollock have been fairly low and individual fish are much smaller than last year. We have been surprised at the numbers of age-0 Pacific cod, the highest catches that NOAA scientist and Bering Sea Project investigator Ed Farley can remember during the BASIS survey.

Surface water temperatures have been 7-10 deg C, reflecting the "cold" year we are having (note: the air temperatures are about the same!). The scientists have been debating what effect the cold water has had on the age-0 numbers and their growth. Back to top

August 22: How to get 7500 pounds of jellyfish in 30 minutes

Yesterday we caught 7500 lb of jellyfish in a 30 minute surface trawl. We knew something was up when the net changed shape under the pressure of the catch. The crew pulled the bag aboard with a crane!

Based on the acoustics (right), we had suspected a big catch after seeing the jellyfish layer within the 30-meter reach of the trawl. See larger image

Among the jellyfish were a few young walleye pollock and Pacific cod. This wasn't the largest jellyfish catch in a single trawl on the BASIS survey (there has been at least one "Melanaster disaster" named for a high catch of the jellyfish species Chrysaora melanaster), but it was impressive.

After another (not nearly as large) catch of jellyfish and sandfish near Amak Island today, both the scientists and crew are occasionally watching the acoustics, hoping to see an end to the jellyfish trawls. As we move into Bristol Bay, we're all hoping for some good fish catches in the upcoming sets. Back to top

August 19: Finding our groove

We're finding our groove for sampling. The first few stations are always a bit slow, as we relearn how to deploy gear and settle in our individual roles.

We have finished five oceanography and surface trawling stations, seeing very different things. Over the deepest water (500m depth), the trawl captured mostly immature chum salmon (right), which have spent 2-3 years in the ocean.

In shallower water (<125m depth), we found mostly age-0 (born this year) walleye pollock and Pacific cod (below).

Lots of jellyfish

The acoustics tell us that below 35m depth, the water is filled with jellyfish. Filled. In 2008, we had learned not to trawl that mass for too long.

When we finally do trawl to collect jellyfish for lengths and species composition, we will fish the net for just five minutes. We may still get several hundred pounds of jellyfish, which may take an hour or more to process.

Different patterns

The patterns in pollock, cod, and jellyfish are different from we had expected to find based on our 2008 and 2009 observations. What other surprises are in store? Back to top

August 17: Heading out and sampling

After a stop at a local store to buy essentials for 20 days at sea, the five scientists who didn't get their luggage are resigned but laughing about it --- they'll probably look like some sort of team in their matching Dutch Harbor gear.

Right: This freighter was docked ahead of the Dyson. Each of the cargo containers on its deck are 40ft long by 10ft high by 8ft wide, and stacked 7 high, 13 wide, and 16 long --- and they weren't done loading yet! Even the 209ft Dyson felt small next to this hulk.

We're heading for our first station located six hours north in 500m of water. A bit of time for everyone to get their "sea legs" before we start the survey isn't a bad idea. The forecast suggests that although we'll sail into 10ft seas tonight, the weather should grow progressively nicer as the week goes on.

Sampling for water properties and zooplankton

The science will start with oceanographic sampling at 0630. At each station, we use a CTD unit (Conductivity-Temperature-Depth) to measure properties of the water from near-bottom to the surface. The CTD is also equipped with Niskin water collection bottles that can be triggered to close at specific depths. Various mesh nets (Bongo, Pairovet, and Juday) will be pulled through the water to obtain samples of zooplankton. See more pictures of a CTD in action and learn more about why we use it to sample ocean water.

Surface trawling to learn about fish

We will then tow a net at the surface (a "surface trawl") to collect fish and jellyfish at each station. The trawl is ~55 m wide and ~20-25 m high. When this net is fished at the surface, the vessel adjusts its speed, the crew adjusts the length of the wire going from the vessel to the net, and floats are placed on the top of the net opening to keep the trawl fishing at the surface. Surface trawling is how we'll get information on salmon species, particularly juveniles, and forage fish.

Acoustics: finding fish the high-tech way

Between stations, we use acoustic equipment -- high tech fish finders -- to map forage fish distribution. A pulse of sound is sent into the water and is reflected by anything that is different from the water -- this allows us to see fish, jellyfish, squid, and zooplankton. Left: How fish and zooplankton appear through the acoustic equipment. See larger image

Air, like in the swimbladders of some fish, reflects a lot of sound energy because it is very different from water. On the other hand, squid bodies are more similar to water and don't reflect as much sound energy. The acoustics sends out sound pulses at a rate of one per second, giving us a very detailed look at the water column as we pass over it.

Midwater trawls for different species

The trawl is fished below the surface (a "midwater trawl") to identify interesting things -- like a school of fish deep in the water -- that we see on the acoustics. From this we get species composition and, by repeatedly sampling things we see on the acoustics, can start to associate patterns on the acoustics with different organisms. We use the same net for midwater trawling as we do for surface trawling, but remove the floats and adjust the fishing to keep it below the surface.

Phew! Enough explanation -- let's get the gear in the water! Back to top

August 16: Welcome to Dutch Harbor!

I made it into Dutch Harbor today. As we approached, there were murmurs among the (primarily seasoned) passengers that you couldn't see high enough up Mt. Ballyhoo, a local measure of visibility, for the plane to land. Would we land or head back to Anchorage or Cold Bay? A break in the fog allowed us to touch down, and as I walked off the plane into 50 F, rain, and wind I was reminded that at that moment Seattle was likely 90 F and sunny. Welcome to Dutch Harbor.

By the end of the night, I knew that most of the science party had arrived and some (I among them) even had their luggage! The second half of the question, "Will I make it into Dutch?" invariably is "... and will my luggage make it?" You have to pack knowing that there is a possibility that your bags may not arrive before the research vessel leaves the dock -- and remember that there are only a few places where you can replace your missing items before you set sail. How's that for a reality check?

Despite all the possible pitfalls in getting here, and the weather, I always feel energized when I get to Dutch. It's ruggedly beautiful, rich in history, and hardworking. Because it's so unlike where many people live, arriving in Dutch can be like a wake-up call that something, maybe something big, is about to happen. Tomorrow that something big is boarding the Oscar Dyson and starting to get set up.

Gear, food ... and hopefully luggage

Under ideal circumstances, getting our gear aboard the ship would simply involve a phone call, but here, it involved five scientists climbing around on piles of gear looking for containers with our labels. Left: looking for the gear.

Earlier surveys had deposited gear in the same place and our gear was near the bottom of the pile. Fishing trawls, small nets, coolers, tubs, bins, bottles, rain gear all came aboard, and by dinner tonight the labs looked like labs.

This afternoon the food arrived -- boxes of potatoes, cases of apples, crates of eggs, huge bags of onions, frozen slabs of meat, jumbo packs of ketchup. Once we sail, I'll ask the Chief Steward just how much food it takes to feed 39 people for a trip like this.

Many scientists don't yet have their luggage. More flights will arrive before we sail; everyone is hopeful that their bags will be on the next flight, so are waiting until the last minute to break down and buy sweatpants and t-shirts at the few stores on the island. Tomorrow may be a frantic shopping spree before the lines are thrown and we head to the first station. Back to top

August 12: Survey overview

2010 will be the third year in which acoustics and midwater trawling for forage fish (e.g. age-0 walleye pollock, capelin, herring) will be combined with normal BASIS operations (surface trawling for juvenile salmon, oceanography) as part of the Bering Sea Project.

The combination of acoustics, midwater trawling, surface trawling, and oceanography is a powerful one because it provides multiple perspectives on the fish community and its underlying habitat.

A closer look at pollock in 2010

This year we will also conduct a special, high-resolution survey of age-0 pollock. In 2008 (a "cold" year in terms of water temperature), age-0 pollock were found in the middle of the survey area, but in 2009 (a "colder" year) they were found in deeper water.

Knowing that 2010 is the "coldest" year since 2008, our goal is to understand what factors influence the distribution of young pollock and how this may affect their survival. Read more about why we do acoustic surveys, and learn more about how the Bering Sea has changed for pollock since 2008. This blog will track the adventures of the Oscar Dyson --- stay tuned for the science party's arrival in Dutch Harbor, AK. Back to top

• Bering Sea Home
• Meetings + Events
• Cruise Planning
• Calendar
• Field Notes
• Field Notes Summary
• 2010
• Forage Fish and Salmon Survey
• Carbon Cycling
• Pollock Surveys
• Thompson (June-July)
• Thompson (May-June)
• Visit to Unalaska
• Polar Sea (Mar-Apr)
• Visit to Togiak
• 2009
• Seabird Telemetry
• At-Sea Patch Dynamics
• Savoonga LTK
• Ichthyoplankton
• Healy (Apr-May)
• Healy (Mar)
• 2008
• Bogoslof + Pribilofs
• Healy (July)
• Healy (Mar-May)
• Healy (Mar)
• Hydrography
• Ichthyoplankton
• Seabird Telemetry
• Pollock
• Sea Ice
• Sounds of the Sea
• Spectacled Eiders
• Walrus
• Winter Oceanography

Acronyms Revealed!
Hover your mouse pointer over acronyms to learn what they stand for.

The BEST-BSIERP Bering Sea Project is a six-year study of the Bering Sea ecosystem,
from the benthos and the atmosphere to human communities, and everything in between.
NORTH PACIFIC RESEARCH BOARD  :: NATIONAL SCIENCE FOUNDATION

Contact the BEST-BSIERP Program Manager with project-related questions.
Contact the Visual Information Specialist with website-related questions.
   

Site Map