Transcript Marine Mammals

Summaries of research-based
knowledge
We hope this helps you decide
on your most important
questions
Click on this Figure to
Return to Resource Guide
RESEARCH SUMMARY CHOICES








Nuclear contaminants
Marine mammals:
persistent organic
pollutants
Marine mammals:
heavy metals
Freshwater fish
Marine fish
Caribou/reindeer
Birds
Biological effects






Climate change
Exxon Valdez Oil Spill
Importance of Native
Foods to Health
Human Health:
persistent organic
pollutants
Human Health:
cadmium
Managing Risk
Or you can always go
back to the Resource
Guide by clicking here
When you finish a summary section,
click on the ANSC logo to return to the
table of contents. You can then go back
to the Research Summary Choices or
any other section of the presentation

“The elders are
wondering about
Russian military
dumping toxic waste
and it is coming over to
our side. I’m glad to be
here and to understand
that we aren’t the only
ones to experience
these changes.”
Eric Iyapana, Little
Diomede
Eric Veigard
Example of Native concern with
nuclear waste from Russia
Russian nuclear wastes
Currently, there is no indication that former
Soviet Union dumping activities caused
elevated concentrations of radionuclides in
Alaskan waters.
 To date, the predicted concentrations of
radionuclides in Alaskan waters from FSU
dumping are so low in all cases that it is
highly unlikely that any significant ecological
impacts will occur in any areas outside the
immediate Russian disposal sites.

Comparison of Russian
Sources with other Sources
Projected doses to Alaska
populations from Russia
Millisieverts per year
Dental Xray dosage
Projected doses to Russian
local populations
Other background natural
radiation
Radon
0
0.5
1
1.5
2
2.5
Exposure to all sources of
radioactivity
 People
with a diet high in
terrestrial and freshwater
foodstuffs receive the highest
radiation exposures, from both
natural and human sources of
radionuclides.
 These foodstuffs include
caribou/reindeer, freshwater
fish, berries, and mushrooms.
 People who eat mostly marine
foodstuffs have the lowest
doses.
Exposures in the Arctic
 The
Arctic terrestrial system is more
vulnerable to radioactive contamination than
temperate areas. The exposure of people in
the Arctic and subarctic is, for the general
population, about five times higher than what
would be expected in a temperate area.
 However, for part of the population the
exposure could be more than 100 times higher
than expected for similar fallout in temperate
areas.
Major human sources of
radiounuclides
 The
major human sources of radionuclides in
the Arctic are global fallout from nuclear
bomb tests, releases from European nuclear
fuel reprocessing plants, and fallout from the
Chernobyl accident.
Radionuclide levels dropped after
atmospheric testing stopped
Drop in Radionuclide Levels
They briefly
increased again
after Chernobyl
Radionuclides in Caribou
 Polonium
from caribou/reindeer dominates
the natural radiation dose, whereas cesium137 from an array of terrestrial food sources
is the most important human sources of
radionuclides.
 There is some confirmation of naturally
occurring potassium 40, polonium 210 and
lead 210 in caribou in Alaska. Levels of lead
210 may vary within herds as they do in
Canada, but we don’t have data to confirm
this.
Dosages from Caribou/reindeer


The highest average exposures to individuals in Native
Arctic populations are in Canada and the lowest in
Greenland. Consumers of large amounts of
caribou/reindeer can have radiation exposures 50 times
higher than the average members of their national
population.
We lack the data to confirm that Alaska animals have
relatively high body burdens of radionuclides compared
to similar or related species in temperate regions. We
also cannot conclude that Arctic animals may be adapted
to relatively high exposure because of the importance of
natural sources of these contaminants.
Exposures to radioactivity



The greatest exposures to radionuclides occurred in
the 1950s and 1960s (e.g. strontium 90). The long
term effects of Strontium 90 in bone perhaps
interacting with exposures to organochlorines is not
known.
Of all radionuclides, lead-210 and polonium-210,
which are natural in origin, may make the greatest
contribution to current human radiation doses in the
Arctic.
However, the greatest exposures to radionuclides
may come from improperly used or maintained
radiological equipment.
Natural sources of radioactivity



Both lead-210 and polonium-210 occur in nature as
airborne particles and tend to settle out on vegetation
(i.e. lichens) thereby entering the terrestrial food
chain (lichens-caribou-humans) (308). We should
also consider polonium-210 levels in fish
It is likely that Alaska Native consumers of Native
foods are exposed to an approximately seven-fold
higher radiation dose than non-consumers of
traditional food
More than 95% of this increased radiation dose is
due to the bioaccumulation of natural radionuclides
in the food chain.
Health risk of radioactivity
 This
increased radiation dose gives
consumers of Native foods a cancer risk that
is approximately 10% higher than that
compared with consumers of a southern diet
 In Alaska, there is a higher incidence of some
cancers (e.g. stomach cancer), but this may
be unrelated.
Russian nuclear wastes and
Alaskan seafoods
 The
potential human health risks associated
with ingesting Alaskan seafoods containing
radionuclides derived from releases
associated with Russian nuclear wastes
evaluated are extremely low.
 Those wastes pose no threat to human
health; Alaska Native communities, therefore,
need not alter any of their dietary habits
associated with subsistence foods obtained
from Alaskan waters.
Marine Mammals: Persistent
Organic Pollutants (POPs)
 There
is some data to support the statement
that marine mammals including polar bear,
ringed seals, beluga, and walrus probably
have elevated levels of PCBs and toxaphene,
but more data is needed.
PCBs in Alaska
 Levels
of PCBs tend to be higher in eastern
Canada. This may be due to a coupling of a
regional cooling trend in eastern Canada with
atmospheric PCBs from lower latitudes of
North America.
 We cannot assume that the trend of
decreasing levels of PCBs from eastern to
western Canada extends into Alaska,
particularly in the Bering Sea.
Walrus: POPs
 Canadian
results show
a large variation in
organochlorines in
walrus. The presence
of many different types
of organochlorines in
some walrus indicates
that the source is not
local (and hence of a
specific type or types).
The variation may be due to differences in diet.
Walrus that eat seals may have higher levels. We
need Alaska data to test this idea.
POPs data for Marine Mammals
 Geographic
coverage of levels of persistent
organochlorines in marine mammals is not
good in Alaska.
 We have not studied contaminant levels in
most stocks or populations of beluga, ringed
seals, walrus, and polar bears.
Recent research
 POP
contaminant levels in the blubber of
Cook Inlet beluga whales are lower than
belugas from the Eastern Chukchi and
Eastern Beaufort seas
 Scientists have found high levels of the
agricultural insecticide DDT in Aleutian
Islands bald eagles
 Killer whales in Prince William Sound and
the Kenai Fiords have been concentrating
dangerous industrial pollutants of
possible Asian origin in their body fat.
Marine Mammals: Heavy Metals from Russia


The most severe effects of metals on Arctic ecosystems
are from local pollution. The nickel-copper smelters on
the Kola Peninsula and in the Norilsk region of Russia
have severely polluted nearby terrestrial and freshwater
environments.
Most of the smelter emissions are deposited very close
to their source. However, they are still the major source
of circumpolar contamination. Emissions from the Kola
Peninsula are the major source of metals in northern
Fennoscandian air, and emissions from the Urals and
Norilsk are the most important for air concentrations of
metals over Alaska and northern Canada.
Marine Mammals: Natural Sources of
Heavy Metals


Metals are taken up by Arctic biota and levels often
reflect local geology or local human activities. In the
circumpolar assessment, the most troubling findings
concern mercury and cadmium, as they occur in
concentrations that may have health implications for
individual animals as well as human consumers.
Geographic coverage of levels of heavy metals in
marine mammals is not good in Alaska. We have not
studied contaminant levels in most stocks or
populations of beluga, ringed seals, walrus, and polar
bears.
Increases in mercury



Mercury seems to be increasing in both lake and ocean
sediments. An increase over the past two to three
decades is also evident in livers and kidneys from some
marine mammals. This may indicate an increased global
flux of mercury, which is deposited in the Arctic because
of the cold climate.
In some parts of the Arctic, notably Greenland and
western Canada, any increase in the mercury load is in
addition to high natural levels from the local geology.
Mercury levels in several species of marine mammals
seem to be highest in the northwestern part of Canada.
Marine Mammals: mercury

Polar bears, ringed seals, and beluga are likely to have
elevated levels of mercury, but we need data to
understand how the sedimentary geology differs in
different areas off Alaska’s coast as compared with the
Canadian Beaufort Sea.
Mercury biomagnifies in
freshwater and in marine
ecosystems. However, in all
marine animal populations,
even the most exposed ones,
selenium is abundant enough
to detoxify the mercury.
Marine Mammals: cadmium

In some areas, cadmium levels are very high in marine
mammals, possibly due to local geology. Cadmium levels
seem to be highest in marine animals from northeastern
Canada and Northwest Greenland. For certain age groups
and populations of marine birds and mammals, the levels
might be high enough to cause kidney damage.
While
cadmium concentrations in beluga
increase from the western to eastern
Canadian Arctic, we cannot assume that
the trend extends across the Alaska
Beaufort, Chukchi Seas, or into the Bering
Sea and Gulf of Alaska. The mineral
composition of sediments may differ from
those in the western Canadian Arctic.
Heavy metals in Marine Mammals

There are likely high levels of mercury and cadmium
in sea birds and marine mammals as observed in
Canada. The biological implications for the animals
themselves is, however, unknown. Given that the
levels of cadmium, for example, are among the
highest ever reported in marine mammal tissues,
further efforts are needed to examine possible
physiological effects.
Example of concerns about
deformities in fish
“Where we are finding reported and proven
contamination (tar, gasoline, fuel oil), we are
also finding deformities in the fish.” Guy Martin,
Nome
“My dad noticed that
maybe one in ten or two
in ten king salmon were
filled with pus. Last
summer it was seven in
ten were filled with pus.”
Paul Erhart, Tanana

Freshwater fish: mercury



Mines are sources of local contamination, but only a
few mines have been assessed.
We don’t know if mercury levels in freshwater fish are
relatively high or low in Alaska. Higher mercury levels
are probably the result of both natural environmental
conditions and human activity.
Increases in mercury concentrations in sediments in
this century may indicate increased human sources.
The correlation of selenium with mercury does not
necessarily indicate that the source of mercury is
natural.
Freshwater fish: mercury
 Mercury
seems to be increasing in both lake
and ocean sediments
 Several uncertainties about the observed
time trends must be resolved before firm
conclusions are drawn
 For example, the gradients in sediments
might be caused by natural processes. For
biota, lack of information about the natural
variation of mercury levels complicates the
interpretation of results.
Freshwater fish: mercury
 From
a research point of view, further studies
of the increase in mercury are a high priority.
It is important to verify time trends and also to
investigate the sources or processes behind
the increase, as well as any biological effects.
Freshwater fish: POPs

Toxaphene is the major organochlorine contaminant in all
freshwater fish in northern Canada. We do not know if this
is the case in Alaska. It may be true that high toxaphene
levels are related to differences in food web structure (i.e.
fish eating other fish that are also predators)
Diagram Source: AMAP, 1997, p. 45
Toxaphene concentrates in fish livers
 Toxaphene
concentrates in fish livers. Burbot
with high levels of toxaphene in their livers
may have concentrations in their flesh that
are comparable to other fish.
Freshwater fish: POPs
 There
is likely to be a wide variation of PCBs in
freshwater fish by location and weight of the fish.
In northern Canada, lakes with the highest
concentrations of PCBs (e.g. Lake Labarge)
have local sources of PCBs and DDT.
 We need data to know if this pattern is also true
in Alaska.
Primary Concerns:
 In
northern Canada, fish of primary concern
due to their contribution to Native diets
include: burbot, lake trout, arctic char,
northern pike, and whitefish.
 We cannot assume that these species are of
primary concern in Alaska; rather, all species
consumed are of potential concern, including
salmon.
Freshwater fish
 We
also cannot assume that PCBs,
toxaphene, and mercury are the primary
contaminants of concern in freshwater fish
 Geographic coverage of contaminants in
freshwater fish in Alaska is poor.
Marine fish: POPs



The major source of persistent organic pollutants in
the Arctic is long-range transport via air currents, as
demonstrated by monitoring of air concentrations.
There may also be significant sources of some
contaminants, such as PCBs, DDT, and
hexachlorocyclohexane, within the AMAP region, but
these are not well documented.
Data from river water and sediments indicate that a
substantial input from Russian rivers into the Arctic
marine environment, but these data must still be
verified.
Availability of Data



Available data point to some geographic trends. In
general, the levels of PCBs and DDT seem to be higher
around Svalbard, in the southern Barents Sea, and in
eastern Greenland than in, for example, the Canadian
High Arctic.
Very limited data from Russia and Alaska are available
for this assessment.
The lack of circumpolar data limits our understanding of
sources, transport pathways, and mechanisms for
focusing contaminants. The role of sea ice in
transporting contaminants and then releasing them
during melting warrants further investigation.
Sources of POPs



We have a poor understanding of how
organochlorines move within the marine food web
There is very limited information on levels of
organochlorines and aromatic hydrocarbons in
marine fish stocks in Alaska waters
Military sites along Alaska’s coast are likely to be
local sources of PCBs and DDT contamination of the
nearshore environment. While there is some Alaska
data to support this conclusion, more data is needed.
Example of concerns about caribou
 “The
only problem is that all those
caribou and other animals wander all
over that hillside. What they are eating
is grass from the hillside. If they are
eating grass up there where the site is
contaminated, isn’t it going to affect
us?” Myrtle Johnson, Nome
Example of concerns about caribou
 “This
year at Onion Portage, there were
caribou with swollen joints, bad white liver
spots, and lungs stuck to the ribs. 12-15%
(50% increase) show these signs.” Enoch
Shiedt, Kotzebue
Caribou: cadmium
 In
some areas, cadmium
levels are very high in
terrestrial mammals,
possibly due to local
geology. For example, in
reindeer/caribou, the
highest cadmium levels
have been recorded in the
Yukon territory in Canada,
which is known to have
cadmium-rich geology.
Applying the Canadian experience
to Alaska
 We
do not have the data necessary to
conclude that an observed increase in
cadmium levels in caribou kidneys from
eastern to western Canada continues into
Alaska.
 We therefore cannot say that the levels in
Alaska are comparable to those in northern
Quebec and Norway, which is the case in
western Canada. The source of cadmium is
probably natural and may be related to soil
and winter forage.
Caribou: cadmium


It is likely that cadmium levels in caribou kidneys in
some Alaska herds are higher than the Canadian
guideline of 30 micrograms per gram, but we don’t
have the data.
We concur with Canadian researchers that the
potential effects of high doses of metals such as
cadmium on caribou are not clear
Radionuclides in Caribou
 Polonium
from caribou/reindeer dominates
the natural radiation dose, whereas cesium137 from an array of terrestrial food sources
is the most important anthropogenic
radionuclide.
 There is some confirmation of naturally
occurring potassium 40, polonium 210 and
lead 210 in caribou in Alaska. Levels of lead
210 may vary within herds as they do in
Canada, but we don’t have data to confirm
this.
Dosages from Caribou/reindeer


The highest average exposures to individuals in Native
Arctic populations are in Canada and the lowest in
Greenland. Consumers of large amounts of
caribou/reindeer can have radiation exposures 50 times
higher than the average members of their national
population.
We lack the data to confirm the Canadian conclusion
that Arctic animals have relatively high body burdens of
radionuclides compared to similar or related species in
temperate regions. We also cannot conclude that Arctic
animals may be adapted to relatively high exposure
because of the importance of natural sources of these
contaminants.
Caribou: POPs


We do not have data to know whether the trend of
decreasing PCB levels in caribou from eastern to
western Canada extends to Alaska.
We can’t say, as the Canadians can, that TCDD toxic
equivalent concentration (TEQ) levels observed in
caribou are comparable to levels observed in
domestic animals in Canada.
Birds: POPs

Geographic coverage of levels of persistent
organochlorines in seabird populations in Alaska is poor


Biomagnification is one major factor contributing to the
high levels and biological effects of persistent organic
pollutants in Arctic animals. Another biological pathway
is via migratory birds that overwinter in polluted
environments
We don’t know how organochlorine levels vary in birds.
We cannot say whether the Canadian observation of
lower organochlorine levels in the western Arctic
extends to Alaska.
Glaucous Gulls
 We
don’t have data to confirm the Canadian
observation of lower levels of
organochlorines in Glaucous gulls in the
western Arctic. Factors affecting
organochlorine levels in the Bering Sea may
be different, for example
O.J. Bustnes
Declining Organochlorine
Levels
 We
need to confirm observed trends of
declining concentrations of organochlorines
in marine mammals and sea birds from the
1970s to the 1980s and a leveling off of
concentrations during the mid-1980s to the
mid-1990s
Trends over time


It is likely that the observed decline in SDDT in
peregrine falcons is greater than that in arctic sea
birds, but we need data to confirm this Canadian
finding
There is limited data on changes in organochlorines
such as toxaphene, chlordane, and chlorobenzenes
in marine biota. What Canadian data there is for the
1980s and 1990s suggests that there has been no
significant decline in concentrations of these
contaminants in marine mammals or sea birds. We
do not have comparable temporal data for Alaska.
Toxaphene

As in Canada, there are no data in Alaska on
toxaphene in terrestrial animals and in waterfowl and
seabirds, despite that fact the likelihood that
toxaphene may be a major organochlorine
contaminant in arctic air, seawater, fishes and marine
mammals
Birds: heavy metals


We don’t know if the Canadian conclusion that there
are low levels of heavy metals in birds applies in
Alaska (lead not tested)
There are likely high levels of mercury and cadmium
in sea birds as observed in Canada. The biological
implications for the animals themselves is, however,
unknown.
Biological effects



All persistent organic pollutants in AMAP’s monitoring
program have been found in the Arctic. The levels are
generally lower than in temperate areas, but for several
substances they are still in concentration ranges in
which effects on some animals are expected.
There could be effects on reproduction of birds from
DDT and of some marine mammals from PCBs and
dioxin-like compounds.
Current concentrations in several Arctic species are
also close to or above thresholds known to be
associated with effects on the immune and nervous
systems. The most vulnerable animals are those high in
the food web, such as polar bear and birds of prey.
PCB’s and Organochlorines
 We
do not have the data to verify the
Canadian observation that most
organochlorine pesticides and PCBs are found
at very low levels and that these levels
decrease as you go north
 At observed levels in the north, the Canadians
do not suspect any effect on reproduction.
Beluga and Ringed Seals


It is likely that organochlorine contaminant levels in
arctic beluga are 10 to 20 fold lower than in St.
Lawrence Estuary (Eastern Canada) beluga. In the
case of St. Lawrence beluga, there is preliminary
evidence of a link to immune system dysfunction due
to high PCB exposure.
It may be true, but we also lack data to confirm that
concentrations of PCBs in blubber lipids of ringed
seals are 10 to 20 fold lower than concentrations
associated with poor reproductive success in captive
harbor seals.
Lack of experimental data on
biological effects
 As
is usually the case with arctic animals,
there is a lack of experimental data
linking dosage with effects.
 There is particularly a need to study
biological effects on the immune system
of mammals that are predators.
Lack of research to link contaminants
with biological effects



The Canadian Northern Contaminants Program
concluded that, with the possible exception of
peregrine falcons, contaminant levels or biochemical
indicators of effects have not been linked to effects
on arctic animals at the individual or population level.
The lack of research of this type in Alaska makes it
impossible to conclude whether or not there have
been effects of contaminants on arctic animals
Local observations of possible effects of
contaminants on the environment are needed.
Marine mammals



It is likely true that marine mammal females and their
offspring may be most vulnerable when the female
draws on her fat reserves. POPs tend to concentrate
in fat. This drawing on fat happens at a crucial point
in the growth and development of the young.
Overall, the MFO enzyme data in Canada for polar
bear and beluga suggest that:
Even the relatively low levels of contaminants
present in the arctic animals may have biological
effects, especially during years of poor feeding.
Biological effects: some
details


More work is needed to confirm observed
correlations of non-ortho and mono-ortho PCB
concentrations with CYP1A1 activity in polar bear
and beluga livers. There is also a need to combine
MFO measurements with other biochemical
indicators of effects of PCBs such as retinol levels
Given that some of the persistent organochlorines
such as o,p’-DDE, p,p’-DDE and –DDT have
estrogen activity, information is needed on steroid
and thyroid hormone levels in polar bears and beluga
Mercury and Cadmium



We concur with Canadian researchers that the
potential effects of high doses of metals such as
cadmium on caribou and beluga are not clear
There are likely high levels of mercury and cadmium
in sea birds and marine mammals as observed in
Canada. The biological implications for the animals
themselves is, however, unknown.
Given that the levels of cadmium, for example, are
among the highest ever reported in marine mammal
tissues, further efforts are needed to examine
possible physiological effects.
Radionuclides


We lack the data to confirm the Canadian conclusion
that Arctic animals have relatively high body burdens
of radionuclides compared to similar or related
species in temperate regions
We also cannot conclude that Arctic animals may be
adapted to relatively high exposure because of the
importance of natural sources of these contaminants.
Example of Native concerns
about climate change
 “Is
there going to be some conclusion at
the end of three years about the effect of
climate change on the observations
people are making? When the winds and
weather patterns are different, it will bring
a lot of change. It could change how
contaminants travel.”
Charlie Johnson, Nome
Examples of Native concerns
about climate change

“Our river - we've noticed that it doesn't freeze across in
the last 10 years. The temperatures are warmer. The
lakes are drying up. The water is low in June, affecting
the fish run - over the last two years. Sockeyes are much
smaller and so are hatchery fish.” Gloria Stickwan,
Copper Center

“What's happening is that because the winters are
warmer, the lakes don't freeze all the way down and
more of the young beaver survive. That's what is causing
them to proliferate.” Paul Erhart, Tanana
Link to
Bering Sea Anomalies
Climate link to environment
We often think of climate
change as global warming
Alaska
has been
getting
warmer
since 1966
Source: Bering Sea Impact Studies (BESIS) http://www.besis.uaf.edu/
But the climate varies a lot from year-toyear (and decade-to-decade), and not just
in temperature
The N. Pacific
experienced
deeper low
pressures
between 1977
and 1988, and
again in 1997
and 1998
Source: Gordon H. Kruse (1998)
Stronger “Aleutian Lows
often” mean:
 Increased
winter storms
 More nutrients mixed into surface
waters
 Northward movement of warmer
water.
 And stronger Aleutian Lows can
occur in association with El Niño
events.
Source: Gordon H. Kruse (1998)
And these conditions often
mean:
Higher
production of
phytoplankton and
zooplankton;
Increased salmon
productivity.
Source: Gordon H. Kruse (1998)
The 1997/98 El Nino was
unusual:
 It
had 2 peaks: August-Sept. 1997 and
Feb.-March 1998.
 Highest global mean temperature
anomalies since recording started in 1880.
 N. Pacific Ocean temperatures were up to
10 degrees Fahrenheit higher than
average in Aug-Sept. 1997
 Deep ocean temperatures off Seward have
been 3-4 °F higher than average since
Jan. 1998
Source: Gordon H. Kruse (1998)
In 1997, aquamarine waters were
recorded for the first time in the
Bering Sea
This shows
the Bering Sea
bloom and the
sediment
plume from
the Yukon
River.
Source: http://visibleearth.nasa.gov/Regions/Bering_Sea/
It was a massive “bloom” of a
tiny phytoplankton
Copyright: Jess Gorick
coccolithophores
Source: www.soc.soton.ac.uk/SOES/STAFF/tt/eh/index.html
The bloom may have made it
harder for seabirds to detect prey
Thousands of short-tailed
shearwaters died in early
August 1997, apparently
from starvation.
But they appeared to adapt
in 1998 by eating more fish.
Source: T.C. Vance et al (1998); Saar (2000)
Conditions including fewer storms, lower
nutrient supplies, less sea ice, and higher sea
surface temperatures may have caused poor
salmon runs in 1997 and 1998
Source: Gordon H. Kruse (1998)
What’s causing these
changes?
 We
don’t know, but we have some
ideas about changes in climate:
– Changes in solar activity (7-17 year
shifts with an average of 11 years plus a
22 year cycle)
– Changes in the position of the moon
(18.6 year tidal cycle)
– Variations in the Aleutian low
– Atmospheric pressure “regime” shifts
(20-28 years)
Then how are Native food
resources affected?
 Water
temps affect phytoplankton and
zooplankton growth, indirectly affecting
fish and marine mammals
 Fish and marine mammals may change
their distribution
 Changes in sea ice cover is a major cause
of 1 and 2.
 Water temps may affect fish production
 But we also need to take into account
human harvests of species and
environmental changes.
Alaska lands and streams are also
experiencing climate change
 Increased
insect infestations in
forests
 Increased risk of catastrophic
wildfires in settled areas and in
coastal forests
 Coastal stream changes affecting
fish
 Thaw of large areas of permafrost
 More forested areas over long term
Source: Berman, Juday, Burnside 1999
Are people the cause of climate change?
In cases like the Exxon Valdez, yes.
 Most
scientists think that greenhouse
gases will contribute to climate change
 For a scientists’ position statement, see
http://www.agu.org/sci_soc/policy/
climate_change.html
 But
not all scientists agree.
 Native people are participating in efforts to
address environmental concerns in the
Arctic. See http://arcticcouncil.usgs.gov/98rep.html
Exxon Valdez Oil Spill
 The
Exxon Valdez Oil Spill Trustee Council
has a ten year report on the web:
http://www.oilspill.state.ak.us/index.html

NOAA has a web site summarizing it’s
Long Term Monitoring research:
http://response.restoration.noaa.gov/bat/about.html
The PWS RCAC has a 1998 report on its
Long Term Environmental Monitoring
Program on the web: http://www.pwsrcac.org/
 We can only touch the surface of this
wealth of research-based information.

NOAA’s Long Term Monitoring
 Generally,
the ecosystem of Prince
William Sound has proved surprisingly
resilient, but
 Impacts from the spill remain in Prince
William Sound, in the form of oil still
leaching from beaches and populations of
plants and animals that haven't yet
completely recovered.
NOAA’s Long Term Monitoring
 Although
little of the
spilled oil
remains,
oily vestiges
are still
evident on
many
beaches.
Source: NOAA http://response.restoration.noaa.gov/bat/about.html
EVOS research results


The plant and animal populations of the Sound seem
to still be adjusting themselves in response to the
spill.
Rockweed cover, for example, increased after the
spill, then decreased in 1994-95.
Source: NOAA http://response.restoration.noaa.gov/bat/about.html
Species still recovering include
 Pink
salmon, mussels, clams, pacific
herring, sea otter, sockeye salmon,
black oystercatcher, common murre
and marbled murrelet
According to the Oil Spill
Trustee Council, “There is
still concern about egg
mortality in some streams
in the western part of
Prince William Sound.”
Source: Oil Spill Trustee Council. 1999
Species not recovering yet include
 Harbor
seals, killer whales, common
loon, commorants, harlequin ducks,
and pigeon guillemots.
According to the Oil Spill
Trustee Council, “Harbor seals
in Prince William Sound and
the Gulf of Alaska have lost 80
percent of their population
over the last 20 years.”
Source: Oil Spill Trustee Council. 1999
People’s harvest and consumption
of Native foods has changed

According to the Oil
Spill Trustees Council,
People of PWS.
“continue to be
concerned over a
scarcity of some
important resources,
including harbor seals,
herring, clams, and
crab.”
Source: Oil Spill Trustee Council. 1999
The future
 The
last big chunk of money from
the Exxon Valdez oil spill settlement
will be rolled into a $115 million
endowment to finance decades of
research into how weather, climate,
fish, birds and sea mammals all
interact in the Gulf of Alaska.
Importance of Native Foods to
Human Health


Native foods are widely consumed within
communities. Marine mammals, large ungulates,
and fish account for a large proportion of Native
foods consumed. Consequently, potential
exposure of Alaska Natives to contaminants in
Native foods is widespread in Alaska
Increases in consumption of imported foods by
Alaska Natives has been associated with
decreased physical activity, obesity, dental
caries, anemia, lowered resistance to infection,
heart disease, and diabetes.
Data on Native Diets



Dietary survey data in Alaska is limited to 12
communities. While there are data on harvests for
many Alaska Native communities, these data do not
contain information on variations in consumption
patterns among individuals (e.g. consumption of
organs, frequency of consumption, method of
preparation)
Consumption of Native foods varies by season and
by year. Dietary surveys which measure consumption
for 2 or 3 24 hour periods may not reliably estimate
consumption of Native foods
Consumption of Native foods varies by region,
income, access to urban centers, and by factors such
as age and gender.
Importance of marine mammals
and fish to human health



Dietary lipids are a concentrated source of energy,
act as carriers of fat-soluble vitamins, and are a
source of essential fatty acids (polyunsaturated fatty
acids that are essential to health but cannot be
synthesized by the human body)
Fish and marine mammals which form a significant
portion of the diet of Alaska Natives contain many
n-3 polyunsaturated fatty acids which are not easily
found in imported foods
Omega-3 fatty acids are found at high levels in fish
and marine mammal tissues and have been
associated with a decreased incidence of thrombotic
and ischaemic disease.
Human health: Persistent
Organic Pollutants
For
a number of persistent organic
pollutants, health concerns include
child development, reproductive
impacts, and effects on the
immune system.
Some contaminants may cause
health problems by disrupting
hormones.
Concern about infant health
 The
developing fetus and breast fed infants
are likely to be more sensitive to the effects
of POPs than adults. Infants are the age
group at greatest risk in the Arctic.
 Fetus/infant intakes POPs through human
cord blood and milk are of primary concern.
 But we are uncertain about the toxic effects.
Advice on Breast Feeding
 We
are uncertain about the toxic effects of
persistent organic pollutants on infants, but
we know the benefits of breast-feeding.
 Therefore, there is good reason for Alaska
Native women who eat substantial quantities
of marine mammals to continue to breast feed
unless told otherwise by their health care
provider.
 However, this advice should be decision of
Alaska Native communities made in the
context of a collaborative program of research
and assessment.
Infectious diseases and ear
infections
 There
is a higher incidence of infectious
diseases and ear infections among Alaska
Native infants
 This may be due to a complicated set of
factors
 It is unknown whether fetus and infant
exposure to PCBs is one of these factors, nor
is the extent of exposure known. But see:
http://ehpnet1.niehs.nih.gov/docs/2000/1083/toc.html or the article based on this
publication in the “notes” section below
Human health: cadmium



Although a major source of human exposure to
cadmium is smoking tobacco, some individuals who
frequently eat kidneys of caribou and marine mammals
(e.g. once a week year round) may ingest significant
amount of cadmium.
However, only a small percentage of cadmium (about 5
percent) is absorbed through ingestion compared with
direct absorption through smoking tobacco.
Smoking may make people’s kidneys less effective in
handling cadmium exposures from frequent
consumption of organs, particularly among the elderly
and diabetics. More study is needed to accept this
theory.
Managing Risk
Importance of Native observations
 Alaska
Natives have observed changes in
the health of some animals and fish.
 They worry that these changes may be due
to contaminants.
 We need to ask knowledgeable Natives to
share these observations in order to see
patterns of change.
Importance of Customary and
Traditional Foods in Alaska
 A substantial
proportion, on the order of a
third or more, of the meat and fish eaten by
rural Alaska Natives comes from local
harvests of fish and game. We do not have
consumption data for most Alaska Native
communities.
 Sharing of Native foods is a common practice
in Alaska. Harvesting, sharing, processing,
and consuming Native foods is an
opportunity to practice and teach humility and
spirituality.
Values of Customary and
Traditional Foods in Alaska
 Imported
sources of meat and fish are
expensive and lower in protein, thiamin,
riboflavin, niacin, and vitamin B12 than
Native foods.
 If Alaska Natives were to stop eating Native
foods, they would experience nutrition and
protein deficiencies.
 Native foods are as important to Native social
well-being as they are to physical health.
Important Environmental
Concerns
 The
diets of Alaska Natives are more likely to
include predators which may concentrate
contaminants. Alaska Native diets are also
more likely to be higher in fats. These fats
may contain higher concentrations of
organochlorines.
 Slower growing plants such as lichen can
result in higher contamination levels through
consumption of caribou.
Sources of Contaminants
Contaminants reach the Arctic through long range
atmospheric transport and exposure of migrating
species exposed to non-local sources of
contaminants.
 Local sites and the natural environment may be
sources of contaminants.
 We need more data to understand the processes
which move contaminants through the food chain.
It is possible that accelerated processes during
the spring may move contaminants through the
food chain more quickly.

Weighing Benefits and Risks
 Traditional
foods have known nutritional
value.
 There is as yet little conclusive scientific
evidence directly linking effects in adults to
the levels of exposure that have been
observed in the Arctic.
 Therefore it is not always clear what public
health measures should be taken to reduce
the exposure of populations who rely on
traditional foods.
Breast Feeding
 Although
there is both scientific and public
concern that breast feeding will transfer
contaminants from the mother to her child,
present knowledge clearly indicates that the
known benefits of breast feeding outweigh
the currently-known risks from contaminants.
To date, there have been no proposals to
limit the duration of breast feeding.
Health Goals


The goal of public health actions should be to reduce
exposure to contaminants without threatening the
social, cultural, spiritual, and physical well-being that is
connected to collecting, sharing, and consuming
traditional foods.
The current traditional diet of Alaska Natives provides a
substantial proportion of energy and protein
requirements as well as most vitamins, essential
elements, and minerals. The high consumption of fish
and marine mammals may contribute to the lower
incidence of heart disease among indigenous peoples
in Alaska, Greenland, and Arctic Canada.
Continued Consumption of
Native Foods



Weighing these known benefits against the
suspected, but not yet fully understood, effects of
contaminants, the conclusion at present is that
consumption of traditional foods should continue.
However, consideration should be given to
developing dietary advice to promote the use of lesscontaminated traditional food items which will also
maintain nutritional benefits.
Such guidelines should be developed at the local
level within the context of local cultures.
International Action


The long-term reduction of exposure to persistent
organic pollutants can only be accomplished through
international conventions on bans and restrictions in
production and use of these substances.
The relative importance of natural and anthropogenic
sources of heavy metals in the Arctic needs to be
determined, and appropriate controls implemented.
Where to go next
Click here to go back
to “Table of Contents”