Home » research

Tag: research

Four Stories about the Spring 2018 Cruise

Lauren Frisch, Public Information Officer for the College of Fisheries and Ocean Sciences, UAF, authored a series of four stories about our May 2018 cruise. Although these stories focus on the on-board capabilities of R/V Sikuliaq, they also include engaging descriptions of our research. Find the links to these stories below:

Sikuliaq expands ways to study Gulf of Alaska ecosystems

Russ Hopcroft at the microscope Studies of zooplankton such as copepods have expanded because of LTER funding and the workspace available aboard R/V Sikuliaq. For instance, CFOS researcher Russ Hopcroft isolates, identifies, photographs, and assesses live animals soon after net tows.
Read full story >>

Submarine ‘airplane’ revolutionizes measurement of seawater content

retrieval of the Acrobat off Sikuliaq's stern CFOS’s Seth Danielson operates an Acrobat instrument, which he described as the underwater version of an airplane. The Acrobat measures temperature and salinity on fine spatial scales. As a result, LTER scientists can track freshwater from the land and investigate how it mixes with ocean water.
Read full story >>

Sikuliaq improves analysis of phytoplankton’s nutrient needs

incubation experiments on phytoplankton CFOS’s Ana Aguilar-Islas brings her own specialized clean sampling instruments onto Sikuliaq so she can quantify nutrients like iron that are essential to phytoplankton. Additionally, Aguilar-Islas and WWU’s Suzanne Strom performed incubation experiments to study how iron availability affects plankton growth.
Read full story >>

Sikuliaq researchers find odd, abundant animal-plant plankton

net tows aboard the Sikuliaq Nutritional flexibility in ciliates and dinoflagellates stabilizes food chains in the Gulf of Alaska. WWU’s Suzanne Strom isolates cells and preserves them soon after they are collected, so she can analyse them at sea and in her onshore lab.
Read full story >>

Sikuliaq Cruise, May 2018

R/V Sikuliaq

In a few short days, 23 scientists and educators will embark on our first LTER cruise aboard the R/V Sikuliaq, April 18 – May 5, 2018. Cruises are integral to our research and we anticipate having three each year – in May, July, and September. This cruise continues decades of time-series of measurements of the spring phytoplankton bloom along the Seward Line. As such, its many objectives center on the physical and biological processes that generate and sustain the spring bloom.

Scientific Purpose

This cruise continues the sampling begun in fall 1997 under the NSF/NOAA NE Pacific GLOBEC program, and supported subsequently a consortium of the North Pacific Research Board (NPRB), the Alaska Ocean Observing System (AOOS), and the Exxon Valdez Oil Spill Trustee Council’s (EVOSTC) Gulf Watch. This is the first cruise as part of the NSF’s Northern Gulf of Alaska Long-term Ecological Program (NGA-LTER). The core scientific purpose of the Seward Line project is to develop an understanding of the response and resiliency of this marine ecosystem to climate variability. This cruise marks the 21st consecutive spring cruise for the Seward Line in the NGA, including Prince William Sound (PWS), and the 48th year of observations at GAK1.

Cruise Objectives

NGA map
Map of Northern Gulf of Alaska sampling stations, 2018.
  1. Determine thermohaline, velocity, light, and oxygen structure of the NGA shelf.
  2. Determine macro- and micro-nutrient structure of the NGA shelf.
  3. Determine particle structure and flux rates of the NGA shelf.
  4. Determine phyto- and microzooplankton composition, biomass distribution, and productivity.
  5. Determine the vertical and horizontal distribution and abundance of zooplankton species (including macro-jellies).
  6. Record multi-frequency acoustics for estimation of nekton
  7. Conduct surveys of seabirds and Marine Mammals
  8. Conduct shipboard experimental work on phyto- and zooplankton.
  9. Determine carbonate chemistry (i.e. Ocean Acidification) at selected stations
  10. Recover and redeploy the GAK1 mooring. Drag for lost mooring at GAK 4 and Gak8i.
  11. Provide at-sea experience for UAF students.
  12. Share the experience through outreach/media activities.

Sampling Plan

To achieve the objectives, the cruise will visit four cross-shelf transect lines plus stations within Prince William Sound. At each station, operations will be divided into day and night tasks. In the day, we will perform CTD measurements, bottle sampling, and perform intensive sampling and productivity experiments at selected locations. At night, net tows for zooplankton will catch the critters when they rise in the water column to feed. The shortness of high latitude nights in May will mean more daylight work than nighttime work.

NGA LTER Begins

LTER Logo

In March 2017, the College of Fisheries and Ocean Sciences and the University of Alaska Fairbanks announced that our Northern Gulf of Alaska research program (the Seward Line) would be joining the National Science Foundation’s Long Term Ecological Research (LTER) program. This is important recognition of 20 years of multidisciplinary oceanographic observations along the Seward Line and within Prince William Sound.

The LTER program networks (now) 28 individual research sites. LTER’s unique ecological investigations measure changes over years and decades in various environments. Each LTER site involves dozens of researchers and depends on partnerships with hosting entities like universities, national forests, or non-profit organizations. There are other LTER sites in Alaska: Bonanza Creek and Toolik Lake, and another new marine site in the Beaufort Lagoons.

Seward Line

The Seward Line is a long-term observational program on the Gulf of Alaska shelf. It was originally undertaken by the Northeast Pacific GLOBEC program from 1998–2004. During the years 2005–2009, sampling along the Seward Line continued with funding from the North Pacific Research Board. Most recently, funding has come from a consortium of NPRB, AOOS, and EVOS (see our Site History.)

The purpose of our research has been to develop an understanding of the response of this marine ecosystem to climate variability. Hence, the Seward Line cruises determine the physical and chemical oceanographic structure, the primary production, and the distribution and abundance of zooplankton. We then examine the seasonal and inter-annual variations in these measurements.

LTER -A New Partner

Having a new partner in the funding consortium will enable expansion of our program’s elements. For instance, a third annual cruise will be performed between the two cruises in May and September. In addition, we’ll be able to perform more in-depth experiments on the processes that enable the high productivity in the Northern Gulf of Alaska area. And finally, the LTER Network’s emphasis on education, outreach, and data availability will also encourage growth in these areas.

Please see the news article for more details:
Long-term site status will boost Gulf of Alaska studies, March 1, 2017.

Cruise Planning

photo of notes

Right now, we are planning our next cruise which will be aboard the R/V Sikuliaq in mid-April 2018. There are a lot of elements that must be balanced when planning a cruise. Of course, time, money (including that for processing samples later on shore), and the program objectives all influence the cruise plan, but there are many other facets to consider.

Elements

For one thing, there are logistical elements that limit where the cruise must start and in what order the stations will happen. These include:

  • Towing for zooplankton must be done during the day, when they are high enough in the water column to catch
  • Productivity experiments must be done during the day when there is sunlight
  • Time spent traveling between sampling locations (deadheading) must be minimized
  • Equipment and personnel must be delivered to and retrieved from the ship

In addition, we must incorporate elements of previous studies to insure continuity between measurements:

  • EcoFOCI sampling stations over the productive sub-marine banks
  • Prince William Sound stations (which can’t be in the shipping lanes)
  • The timing of Seward Line stations with respect to the Spring Bloom

And unfortunately, bad weather can impact the best made plans.

photo of bad weather
Photo by Lisa Seff, Sept. 2017 aboard the Sikuliaq