Bio-Sampling

Health Assessment of Chukchi Sea Stock

Overall Goal:

To obtain baseline measures of health before further environmental and anthropogenic impacts and to compare with other belugas in different geographic locations.

The Immune System protects the body from damage caused by invading bacteria, viruses, fungi and parasites. Blood is the “window to the immune system” which is the “window to health”.

Red blood cells (small pinkish cells) and white blood cells (larger purplish cells)

Beluga harvest in subsistence hunt in Point Lay

Specific Aims:

• To obtain blood samples from live capture-released belugas.
• To obtain blood samples/organs from subsistence hunted belugas for:
  • Immune function
  • Stress and reproductive hormones
  • Complete blood cell counts and serum chemistries
  • Pathogen exposure
• To compare results with belugas from other locations.
• To ensure health of stock as a resource to hunters.
• To deploy a Critter Cam on a live capture-released beluga to gather behavioral data and to use for education and outreach.

Tracy with subsistence hunted beluga samples in a makeshift lab in house in Point Lay	Automated blood analyzer set up in the Kali School in Point Lay
Critter Cam on a beluga whale at Mystic Aquarium

Preliminary Conclusions:

• 45-50 milliliters (or about 3 1/2 tablespoons) of blood is a sufficient sample size.
• Blood samples are still usable after freezing.
• Samples from live capture-released whales is successfully analyzed.
• The shorter the post mortem time the better for subsistence hunted belugas.
• Post mortem blood samples are usable but should be interpreted with caution.
• Automated machines and additional personnel to help provides optimal sampling and results.
• Improvements needed for the Critter Cam deployment on live capture-released belugas.

Future Improvements and Directions:

• Increase sample size for live capture-released belugas and subsistence hunted belugas.
• Investigate age and sex differences.
• Timing (to better match up with time of hunt).
• Conduct a lag time study for post-mortem blood cell viability.
• Comparison of data with other beluga groups (including aquaria populations).
• Integration of immune data with other data for complete picture of health.

Stomach Contents of Alaska Belugas

Purpose:

To better understand beluga diet since publication of Seaman et al. 1982. Beluga stomachs were collected from 1977 to 1981 in Elim (3), Kotzebue Sound (93), Point Hope (18), Wainwright (3), and Barrow (1).

From Bristol Bay in spring, this beluga stomach is full of rainbow smelt.

Stomach contents are rinsed over screens	Mixed hard parts from a beluga stomach
Close up of hard parts from a beluga stomach	The species and size of fish eaten can be determined from these fish otoliths (ear bones) found in a beluga stomach

Beluga swallow fish whole, head first. They do not chew their food as seen by these salmon found in a beluga stomach.

Note: These flatfish are from a bearded seal stomach but they are the same fish beluga eat

Note: These sculpin are from a bearded seal stomach but are similar to what beluga eat

Rainbow smelt in beluga stomach from Bristol Bay

Isopods from beluga stomach (about 2-3 inches long) from Bristol Bay

Note: This amphipod is from a bearded seal stomach but are also eaten by belugas

The two maps below do not include stomach data published in Seaman et al. 1982.

Publications:

• Seaman, G. A., et al. 1982. Foods of beluga whales (Delphinapterus leucas) in western Alaska. Cetology 44: 1-19.
• Quakenbush, LT, RS Suydam, AL Bryan, LF Lowry, KJ Frost, and BA Mahoney. 2015. Diet of beluga whales, Delphinapterus leucas, in Alaska from stomach contents, March-November. Marine Fisheries Review 77(1):70-84.

Examining Beluga Diet Using Blubber Fatty Acids and Stable Isotope Analyses of Multiple Tissues

Purpose:

To study the diets of beluga whales by analyzing stable isotopes and fatty acids, and to explore the effects of non-dietary factors on the beluga diet using Quantitative Fatty Acid Signature Analysis (QFASA). This project will also examine the sensitivity of QFASA diet estimates for use with belugas.

How to study beluga diets:

Methods:

• Sample Collection
  • Point Lay – 2002, 2005-2008
  • 115 belugas samples
  • For fatty acids: full depth blubber core samples
  • For stable isotopes: skin, muscle, liver, bone

Heather Smith taking a blubber sample from subsistence hunted beluga in Point Lay

Stable Isotope Analysis

The blubber sample is dried, ground, put into the analyzer. The data are displayed on a spreadsheet. Below is an example of stable isotope of nitrogen in a food chain. The amount of the stable isotope increases as the food travels up through the trophic levels.

Fatty Acid Analysis

Fatty acid molecules are building blocks of fats. They consist of a carboxyl group (O-C=O) on one end, and a chain of carbon and hydrogen (C-H) atoms on the other end. There are about 65 different types of fatty acids found in marine organisms. Fatty acids differ in the length of the C-H chains, the ratio of C:H, and the branching of the chains.

Organisms tend to contain certain types of fatty acids, depending on when, where and what they eat. If you analyze the fatty acid content of these organisms, you will end up with a signature that varies for each species.

The squid and the mackerel fatty acid signatures vary by the types of fatty acids found in their tissues. The numbers on the x-axis indicate the length of the fatty acid chains (i.e. – 14:0 means there are 14 carbons in the chain) and the number of missing hydrogen atoms (0 = 2 missing H, 1 = 4 missing H, etc.).

As these prey species are eaten by the beluga whale, the fats are carried in the bloodstream for use as an energy source. They are also deposited for long term storage in fatty tissues, which is mostly the blubber layer for belugas.

What is QFASA?

• Compares fatty acid composition of predator with potential prey items.
• Has been used to estimate diets of polar bears, seals, sea lions, seabirds.
• Not yet used to estimate beluga diet.

Are QFASA diet estimates sensitive to sampling from various body sites?

• Six body locations were chosen as areas most likely to be sampled via remote-biopsy in free-ranging animals.
• Samples were obtained from 20 belugas harvested in Point Lay in 2002.

Are QFASA diet estimates sensitive to sampling at various blubber depths?

• Three layers were chosen to be compared to work on the east coast of Canada (Nozeres et al., 2001).
• No obvious layering was visible.
• Blubber thick enough to easily cut into 3 pieces.
• Samples were obtained from 95 belugas during harvested in Point Lay in 2002 and 2005-2008.

Summary of Results:

Quantitative Fatty Acid Signature Analysis (QFASA)

• No difference was found in diet estimates among body sites.
• Diet estimates did differ with blubber depth.

Stable Isotopes

• No evidence of diet differences with age of beluga.
• Adult males feed at a higher trophic position (higher on the food chain).
• Diet does differ over time, which is an indication that the belugas feed on different prey and/or in different areas over time.

Future Plans:

• 2010 – 2012: 29 beluga samples sampled for fatty acids and stable isotopes.
• 2011-2011: prey library, about 425 fish collected from about 35 species for fatty acid analysis.
• Fish are being processed at Dalhousie University.
• Beluga samples being processed and analyzed: next update in 2013.

Recommendations:

Captive feeding study should be done to verify QFASA fatty acid estimates.