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3
Research Themes
I n 1999, the National Research Council (NRC) concluded that marine
populations are best protected by protecting the entire ecosystem to
which they belong (NRC, 1999a). This approach demands a compre-
hensive understanding of the mean state and climatology, key habitats
and their inhabitants, and variability on all relevant scales. In addition,
understanding interactions and linkages between physics, chemistry, and
biology requires interdisciplinary, integrated, and comprehensive studies
of those ecosystems. The North Pacific Research Board (NPRB) offers an
exciting opportunity to provide this kind of comprehensive under-
standing.
Based on the committee's expertise, a large scientific workshop
(Box 1-1), and site visits to eight Alaskan communities and Seattle, Wash-
ington, (Box 1-2), several broad research themes in the North Pacific,
Bering Sea, and Arctic Ocean region were identified: ecosystem states
and variabilities; human-induced effects; economic, social, and manage-
ment research; and forecasting and responding to change. Each of these
themes may contain the components discussed in Chapter 2 (e.g., a con-
ceptual foundation; long-term, short-term and modeling studies; a range
of measurement scales; interdisciplinary approaches; geographic focus).
They are discussed and detailed in this chapter. A better understanding
of these themes will aid the NPRB in achieving its goals and mission.
32
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RESEARCH THEMES 33
ECOSYSTEM STATES AND VARIABILITY
Dynamics of Marine Ecosystems
Circulation in the North Pacific, Bering Sea, and Arctic Ocean critically
influences the region's ecosystems by exporting the excess of fresh water,
nutrients, and marine organisms from the North Pacific through the
Bering Sea and into the Arctic Ocean. There is a net flow of water
(~1 Sverdrup) from the Gulf of Alaska through the Bering Sea into the
Arctic Ocean (Roach et al., 1995). This throughflow removes excess fresh
water from the North Pacific, which carries nutrients onto the Bering shelf
and becomes sea ice further north. Because of the influence that ocean
circulation has on the region's ecosystems, additional research is needed
to understand the processes that control ocean currents, their variability,
and their role in supporting marine life.
For more than a century, oceanographers and marine biologists have
studied the interactions between the photosynthetic production of organic
matter and nutrient dynamics in the sea. While bottom-up processes drive
many ecosystems, top-down processes, although sometimes controversial,
can also be important (Foster and Schiel, 1988). Predation by top-level
carnivores, such as many marine mammals, can have cascading effects
through an ecosystem. These effects are felt by immediate prey such as
plankton, fish, and invertebrates but can also be seen in changes to com-
munity composition (i.e., reduction in secondary prey species) and struc-
ture (i.e., physical disturbances). Most historical research has been field
oriented and interdisciplinary, occurring at the intersections of research
in physics, analytical chemistry, cell physiology, and ecology. The global
database derived from this collective effort established a sound scientific
understanding of nutrient dynamics and the vital role of microorganisms,
both autotrophic and heterotrophic, in the coupled organic matter pro-
duction and decomposition cycles in the sea. However, novel approaches
employed over the past two decades, including new designs in field
experiments, repeat field observations and remote sensing capabilities,
updated methods of sample analysis, and advancements in ecosystem
numerical modeling, have led to a revolution in theories about the mecha-
nisms and controls of nutrient dynamics in the sea.
Contemporary paradigms will continue to evolve as new data and
new ideas are presented for open discussion and debate. An example of
such a paradigm shift is a hypothesis referred to as "greenbelt" (Springer,
1996). Based on this concept, specific regions in which sustained high
levels of chlorophyll concentrations exist in the North Pacific and Bering
Sea, extending into the Arctic Ocean, are believed to support the abun-
dance of higher trophic levels. The presence of the greenbelt is believed to
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34 ELEMENTS OF A SCIENCE PLAN FOR THE NPRB
be a result of the complex physical, chemical, and biological interactions
outlined above. Other examples of interdisciplinary interactions and link-
ages specific to regions of the NPRB focus are presented below. Sea ice is
discussed separately because of its critical role in many ecosystems.
The North Pacific
Mesoscale eddy variability, with spatial scales ranging from tens to
hundreds of kilometers, is frequently observed in the Gulf of Alaska along
the shelves and slopes (Crawford et al., 1995). These eddies are among
the important mechanisms (in addition to wind-driven tides and front-
related processes) that control rates of vertical mixing, which in turn influ-
ence nutrient concentrations and primary productivity. These mesoscale
features might also be important in the exchange of water masses and
their properties across the passages in the Aleutian Islands, although fur-
ther research is needed in this field. Similarly, their effect on the Gulf of
Alaska and Bering Sea ecosystems is yet to be determined.
In the North Pacific, large-scale atmospheric processes are critical for
water exchange between marginal seas and the Pacific Ocean. During the
1980s, the zonal pattern of atmospheric transfer predominated completely,
and intensive water exchange between both the Bering Sea and the Sea of
Okhotsk with the Pacific Ocean occurred. Since the early 1990s, a transi-
tional trend developed from a zonal to a meridional pattern of atmo-
spheric circulation. The Aleutian Low Pressure Index and pressure
gradient between the Siberian High and Aleutian Low declined. As a
result, the water exchange declined, current patterns changed, and low
sea surface temperature occurred. The decrease in water exchange con-
tributed negatively to the heat budget of the upper pelagic layers.
The most abundant commercial fish, walleye pollock, is a thermo-
philic fish species in comparison with herring and arctic cod. In the 1990s,
the severe cooling of shelf waters resulted in unfavorable conditions for
pollock (Radchenko et al., 2001), and their abundance and distribution
declined in the northwestern Pacific. This decline corresponded to the
beginning of a cold regime in the marginal seas, while, in the second half
of the 1990s, Pacific herring stocks increased in the Okhotsk Sea and
western Bering Sea. In the Bering Sea, the herring were related to the
"historically most abundant" (Naumenko, 2001) year class appearance in
the anomalously cold 1993. Nonetheless, conceptual theories of how
atmospheric variations are influencing marine life remain in their infancy,
and further research is needed to determine if there are causal links.
Benthic communities and their associated dynamics in the North
Pacific are complex. Much of the North Pacific contains a relatively deep,
soft bottom habitat. In this region, formations such as seamounts exist
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RESEARCH THEMES 35
that contain complex communities. These deep water habitats have been
explored to some extent around locations such as the Kodiak and the
Aleutian Archipelago, but much information still must be acquired. For
example, trawl survey data indicate that these areas have a high abun-
dance and diversity of cold-water corals and that many fish groups are
associated with particular types of corals (Heifetz, 2002). However, improve-
ment in the quality of these data is necessary to help managers make
rational decisions for the conservation and protection of corals in Alaska.
Likewise, in nearshore waters, kelp and the northernmost seagrass com-
munities are found. These highly productive areas are nursery and feed-
ing grounds for a diverse array of invertebrate, fish, and mammal species.
The Bering Sea
The throughflow of North Pacific water into the Bering Sea through
the eastern Aleutian passages provides a source of fresh water from the
Alaskan Coastal Current into the southeastern Bering Sea via the Aleutian
North Slope Current. Its direct influence on the southeastern Bering eco-
system is recognized but not fully understood. Yukon River runoff
provides a critical seasonal buoyancy flux to the central Bering shelves,
enhancing the baroclinic flow of the Alaska Coastal Current on its way
toward the Chukchi and Beaufort Seas (NRC, 1996). Unfortunately runoff
measurements were discontinued in the 1990s, and temperature measure-
ments (for heat flux estimates) are not available at all.
The Bering Slope Current (BSC) experiences frequent along-slope
mesoscale eddies (of the order of tens of kilometers). These eddies are
believed to carry nutrient-rich saline waters onto the slope and outer
shelves of the Bering Sea, thereby affecting the ecosystems there (i.e.,
greenbelt productivity along the Bering slopes, to the south of St. Lawrence
Island, and north toward the Chukchi Sea). Quantitative understanding
of the BSC, including the generation and propagation of mesoscale eddies,
is necessary to determine the linkage between eddies and productivity.
In the fall, occasional reversals (1-2 sverdrup or more) of the north-
ward flow through the Bering Strait (Roach et al., 1985; McLean et al.,
2001) bring cold, fresh water from the southern Chukchi Sea into the
northern Bering Sea. Effects of this reversal on the northern Bering Sea
ecosystems are not understood.
Phytoplankton blooms in the Bering Sea appear to be initiated by
either ice melt (early bloom) or insolation (late bloom) (Eslinger and
Iverson, 2001; Stabeno et al, 2001; Hunt et al., 2002). If there is an early
bloom in cold meltwater, most of the primary production goes to the
benthos (Alexander et al., 1996). High zooplankton production is associ-
ated with late blooms in warm water, with most of the energy remaining
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36 ELEMENTS OF A SCIENCE PLAN FOR THE NPRB
in the water column (Niebauer et al., 1990; Hunt and Stabeno, 2002; Hunt
et al., 2002). This ice versus solar initiation of blooms is thus hypoth-
esized to have a two-state character for the ecosystem: benthic versus
pelagic (Walsh and McRoy, 1986; Hunt et al, 2002). It is likely that in the
northern Bering Sea, ice remains sufficiently late in the year that most
spring blooms are associated with the ice melt (Cooper et al, 2002). Most
production occurs as the ice recedes in May from the northern Bering Sea,
while in the southeastern Bering Sea, the type of bloom depends on the
timing of ice retreat.
Because different species are adapted to different temperature optima,
the species composition of ecological communities may change with a
change in temperature. For example, the species composition of the
phytoplankton assemblage will dramatically affect the efficiency of trans-
fer of primary production through the Bering Sea food web. This situation
is not unique for cold ecosystems such as the Bering Sea, but it may be
exacerbated by the monospecific nature of the phytoplankton blooms that
characterize high-latitude ecosystems. The coccolithophorid blooms of the
1990s in the Bering Sea (Sukhanova and Flint, 1998; Stockwell et al., 2001)
may have represented an analogous situation. In contrast, when diatoms
dominate the phytoplankton they may constitute a more palatable food
source for zooplankton. In any event, the variable, and often mono-
specific, nature of phytoplankton blooms in high-latitude environments
(Sullivan et al., 1993; Arrigo et al., 1999; Sherr et al., 2003) indicates that it
is imperative to characterize phytoplankton community structure in order
to understand the fate of primary production in the Bering Sea.
Zooplankton production can be affected either by the abundance of
prey (phytoplankton and microzooplankton) or by the ability of the zoo-
plankton to assimilate food and convert it into biomass. In the southeast-
ern Bering Sea, available evidence suggests that phytoplankton produc-
tion during the spring bloom does not limit mesozooplankton grazing
rates. Walsh and McRoy (1986) interpreted the presence of a subsurface
chlorophyll maximum in the middle domain as evidence of transfer of
phytoplankton to the benthos and a lack of tight coupling between pri-
mary production and copepod grazing. They hypothesized that the fate
of production in the southeastern Bering Sea is influenced by water tem-
perature (see also Vidal, 1980; Vidal and Smith, 1986; Townsend et al.,
1994). Water temperature exerts a strong influence on the growth rates of
zooplankton, and it is often thought of as more important than food avail-
ability for limiting the growth rates of small-bodied copepods (McLaren,
1963; Corkett and McLaren, 1978; Vidal, 1980; Dagg et al., 1984; Huntley
and Lopez, 1992). Thus, Walsh and McRoy (1986) hypothesized that in
years with warm water, zooplankton would capture more of the primary
production than in cold years. This relationship depends on the assump-
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RESEARCH THEMES 37
tion that phytoplankton growth is less sensitive than zooplankton growth
to water temperature. This hypothesis has yet to be tested for the phyto-
plankton and zooplankton of the eastern Bering Sea shelf.
The Bering Sea contains a large and productive coastal shelf. This shelf
is pivotal in much of Alaska's flatfish and crab fisheries. While information
is known about some of these areas and fisheries, community interactions
and trophic changes occur there that are still a mystery. For example, there
has been a dramatic increase in jellyfish of the Bering Sea, but its cause
and the effect that these predators are having on fish stocks is unknown
and controversial (Brodeur et al., 2002). Similar mysteries exist in near-
shore regions. The Bering Sea contains important feeding grounds for
many seabirds and marine mammals. Some mammals, such as the gray
whale, migrate from Mexico to Alaska every year to reach the rich amphi-
pod beds in the Chukchi Sea. Currently there is concern about the state of
the feeding grounds because hundreds of gray whales have been stranded
dead along their migratory beaches (Moore et al., 2003). Likewise, it is
known that kelp beds along the Aleutians are disappearing because sea
otter densities have decreased to a point where they can no longer keep
sea urchin populations in check, but there is still much controversy regard-
ing the causes of the sea otter decline (Estes et al., 1998). Similarly, reasons
for the declines in Steller sea lions and harbor seals and the possible increases
in killer whales are still being debated (Estes et al., 2003; NRC, 2003b).
Arctic Ocean
The northward flow of Pacific water through the Bering Strait pro-
vides a significant linkage between the North Pacific-Bering Sea and the
Arctic Ocean (see Figure 3-1). The advection of nutrient-rich water from
the northern Bering Sea-Gulf of Anadyr (Maslowski et al., 2003) extends
the high ecosystem productivity from the Bering Sea into the Arctic Ocean.
Moore et al. (2003), however, documented a sharp decrease in zooplankton
abundance in the northern Bering Sea from 1983 to 2003. The southern
Chukchi-Beaufort Seas have been known for centuries as whale migration
routes, for the abundance of other marine mammals, and for bird colonies.
The Native communities that settled along the northern Alaskan coasts
have always depended on whale subsistence hunting as the main source
of their diet (and survival).
Typical pathways of Pacific water into the Arctic Ocean extend north-
ward from the Bering Strait through the Chukchi Sea via three distinct
branches (western, central, and coastal) (Weingartner et al., 1998), then to
the east and possibly north into the Beaufort Sea (Maslowski et al., 2001).
Shelf-basin interactions along the outer shelves and slopes of the Chukchi
and Beaufort Seas define the rates of exchange between Pacific water and
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38 ELEMENTS OF A SCIENCE PLAN FOR THE NPRB
Minimum Beaufort
East Sea
70 N Siberian
Sea
Maximum
Siberia Alaska
65 N
Yukon River
Minimum
60 N
Maximum
Bering Sea
55 N
Gulf of Alaska
500 km
180 W 175 W 170 W 165 W 160 W 155 W
Beaufort Gyre
Siberian Coastal Current
Alaska Coastal Water
Bering Shelf Water
Aleutian North Slope Bering Slope Anadyr Waters
Alaskan Stream
Atlantic Water
September ice edge maximum and minimum extents
March ice edge maximum and minimum extents
FIGURE 3-1 Schematic diagram of circulation in the Bering Chukchi region of the
Arctic. Flow over the Bering Sea shelf consists of waters drawn from the Alaskan
Stream, which feeds the Bering Slope Current, and fresher water from the Gulf of
Alaska shelf, which contributes to northward transport over the eastern Bering shelf.
In the Chukchi region, the Siberian Coastal Current transports fresh, cold water from
the East Siberian Sea. Maximum (March) and minimum (September) ice coverage
and their variations are shown by dashed lines (adapted from NOCD, 1986).
SOURCE: Macdonald et al., 2003a.
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RESEARCH THEMES 39
ambient arctic water masses. These processes contribute to the mainte-
nance of the arctic cold halocline, a water column feature that through
increased stratification prevents melting of the multiyear ice pack by the
underlying warm Atlantic water, which is distributed throughout the
Arctic Ocean via boundary (slope) currents (Smethie et al., 2000). In turn,
Atlantic water is distributed throughout the Arctic Ocean via currents
moving counterclockwise along the slope at the basin margins. The
boundary between the domains of Pacific water and Atlantic water within
the Arctic Ocean is a major feature that can change in response to arctic
climate regimes (cyclonic versus anticyclonic) (Maslowski et al., 2000;
Macdonald et al., 2002), which are controlled in part by the Arctic Oscilla-
tion (Thompson and Wallace, 1998), the northern hemisphere weather
pattern centered in the Arctic Ocean. The dynamics of boundary current
mechanisms controlling shelf-basin exchanges and their response to climate
regime shifts are currently being investigated as a part of the National
Science Foundation (NSF)-led Shelf Basin Interaction (SBI) program.
Understanding the long-term variability of the above phenomena and
their effect on the region's ecosystems could be one of the NPRB research
themes, extending the multiyear measurements and ecosystem modeling
in the western Arctic Ocean beyond the lifetime of the SBI program.
The central Arctic Ocean supports bacterial and heterotrophic micro-
zooplankton biomass similar to levels found in other pelagic regions of
the world's oceans. Microzooplankton can be major bacterivores and herbi-
vores, and they may be a significant food resource for macrozooplankton
in the Arctic (Sherr et al., 1997). In turn, their food resources include both
phytoplankton and bacteria, the latter possibly supported by the relatively
high Arctic standing stocks of dissolved organic matter (Wheeler et al. 1996).
The Arctic Ocean also directly and indirectly supports many marine
mammals such as polar bears, ring seals, and bowhead whales; however
logistical constraints and political boundaries have left much of this area
largely unexplored. Some limited pelagic and benthic-related research has
been conducted on the Chukchi and Beaufort Sea shelves (Grebmeier et
al., 1995), which are of great biologic and economic importance because
they sustain some of the most productive and highly diverse ecosystems
in the world. Nonetheless, there remains a lack of fundamental under-
standing of these regions that for centuries have been used for subsistence
harvest by Native communities.
Sea Ice
Sea ice is possibly the most influential environmental element affect-
ing the ecosystems in the Bering Sea and Arctic Ocean. In winter, sea ice
generally extends south to the shelf break in the Bering Sea, and it extends
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40 ELEMENTS OF A SCIENCE PLAN FOR THE NPRB
to the coastlines of the Chukchi and Beaufort Seas. Regions of significant
sea-ice formation are in the Gulf of Anadyr and along the coast of
St. Lawrence Island, a consequence of the formation of polynyas1 due to
the prevailing wind direction tending to move ice southward. Salt brine
rejection due to ice formation increases the salinity of shelf waters, which
might flow toward the Bering Strait into the Arctic Ocean or downslope
into the deep northwestern Bering Sea. Sea ice that is advected southward
melts along the edge, cooling water along its path. The cold-water pool
provides specific physical settings for the distribution of nutrients and
fish due to water column stratification and its water mass properties.
Large seasonal and interannual variations in ice cover in the marginal
ice zone (MIZ) have been observed from both satellite images and ship
observations (winds can change the distribution of sea ice in the Bering
Sea and the Arctic Ocean at synoptic time scales, that is, around three to
seven days.) Although the annual variation is large, interannual variations
can be just as large or even larger. For example, the minimum observed
ice extent in March can be smaller than the maximum observed ice extent
in September. Oceanographic phenomena such as the lee polynya found
to the south of St. Lawrence Island (Cooper et al., 2002) or the flaw lead
system2 found along the Arctic Beaufort shelf (Reimnitz et al., 1994;
Carmack and Macdonald, 2002) are structures that have local or regional
importance for biology and can change over various time scales . Under-
standing the interactions between the atmosphere, ocean, and sea ice that
influence variations in the size, location, and seasonality of these polynyas
is necessary to differentiate between the effects of climate change and
climate anomalies on sea-ice conditions.
The seasonal sea-ice cover in the Bering Sea has a dominant effect on
ecosystems. The annual range of ice cover, from the north of the Bering
Strait in summer to the Bering slopes in winter, defines extremely differ-
ent conditions for air-ocean coupling and their subsequent effects on
marine life. Sea-ice formation, melting, and advection determine vertical
exchanges and water mass properties, which in turn affect nutrient con-
centrations, the occurrence and timing of spring blooms, and rates of
primary productivity. Sea-ice formation in the Gulf of Anadyr and subse-
quent salinization of the water column via brine release in the northwest-
ern Bering Sea (simulated in coupled ice-ocean model runs) may enhance
shelf-basin mixing, thus contributing to the high greenbelt productivity
1A polynya is a large area of generally open water in the sea ice. Coastal polynyas are
usually due to strong offshore winds that break up the ice as fast as it forms and push it
away from the land--some may be caused by strong currents between islands. Those occur-
ring in mid-ocean ice sheets may be the result of upwellings of warm water.
2A lead between the fast ice and the pack ice is called a flaw lead.
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RESEARCH THEMES 41
in the region (NRC, 1996). These two processes may also contribute to the
overall cyclonic (counterclockwise) circulation of the deep Bering Sea with
the Kamchatka and Anadyr Currents distributing water masses along the
western side of the sea.
Specifically, the spring ice-edge bloom varies with the location of the
ice edge and depends on the properties of the underlying water masses.
From early spring, solar radiation penetrates both leads and the ice itself,
initiating algal production both within and under the ice. Light measure-
ments have shown that the melt ponds act as windows, permitting the
transmission of incoming solar radiation through to the underlying sea
ice, thus accelerating the melting process and enhancing under-ice pri-
mary production. Studies during the mid-1970s (Niebauer et al., 1981)
and late 1980s (Niebauer et al., 1990; Niebauer et al., 1995) reflect an
intense spring phytoplankton bloom associated with the retreating ice
edge in the Bering Sea. Stratification due to meltwater and surface water
insolation along with high nutrient concentrations triggers this bloom,
which is typically limited by nutrient availability (Niebauer et al., 1990).
The spatial domain of the bloom is controlled primarily by sea-ice
dynamics; local winds; and eddies, fronts, and current meanders. While
the spring ice-edge bloom is usually short-lived (on the order of a week),
it is believed to be a significant component of the annual primary produc-
tion on the Bering Sea shelf (Niebauer et al., 1990), although further studies
are needed.
The extensive pack and fast ice that forms in arctic regions also pro-
vides a unique habitat for polar microbial assemblages. Algal communi-
ties, in particular, are known to flourish within the distinct micro-habitats
that are created when sea ice forms and ages. The primary advantage
afforded by sea ice is that it provides a platform from which algae can
remain suspended in the upper ocean where light is sufficient for net
growth. These autotrophic organisms have a critical role in polar marine
ecology. For example, although rates of primary production by sea-ice
algae are generally low compared to their phytoplankton counterparts,
they are often virtually the sole source of fixed carbon for higher trophic
levels in ice-covered waters. Furthermore, sea-ice algae have been shown
to sustain a wide variety of organisms through the winter months when
other sources of food are lacking.
Pack ice also exhibits consistently higher rates of primary production
relative to land-fast ice in the Arctic, generally by a factor of four or more.
Therefore, pack ice may represent the more important sea-ice habitat in
terms of providing a food source for upper trophic level organisms. The
importance of these differences in food web structure is further magnified
by the fact that pack ice is so much more prevalent than fast ice in the
Arctic. Therefore, changes in the distribution of ice types (first year or
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42 ELEMENTS OF A SCIENCE PLAN FOR THE NPRB
multiyear, land-fast or pack ice) that have recently been witnessed in the
Arctic Ocean are likely to have important, but still unknown, bottom-up
consequences for the food web.
The ice conditions affect higher trophic levels as well. For example,
during cold conditions, predation pressures on age-1 pollock by their
major piscine predators--adult pollock, arrowtooth flounder, and Pacific
cod--were intense (Wyllie-Echeverria and Ohtani, 1999). In the relatively
warm 1980s, strong year classes of pollock have been found to occur syn-
chronously throughout both the eastern and the western Bering Sea
(Bulatov, 1995) and coincide with above-normal air and bottom tempera-
tures and reduced ice cover (Decker et al., 1995; Quinn and Niebauer,
1995). These favorable years of production are the result of good juvenile
survival and have been shown to be related to the amount of cold-water
habitat present (Ohtani and Azumaya, 1995), the distribution of juveniles
relative to the adult population to avoid predation (Westpestad et al.,
2000), and enhanced rates of embryonic development in warmer water
(Haynes and Ingell, 1983). From Arctic shelf locations where benthic com-
munities do not have any autochthonous carbon production we know
that ice-associated and pelagic production provide the major food input
for the benthos. Very little is known about these relationships in shallow
coastal waters, especially in boulder field areas where macroalgae provide
a second, benthic source of carbon production.
The Oscillating Control Hypothesis predicts that southeastern Bering
Sea pelagic ecosystem function will alternate between primarily bottom-
up control in cold regimes and primarily top-down control in warm
regimes (Hunt et al., 2002). Late ice retreat (late March or later) leads to an
early, ice-associated bloom in cold water (e.g., 1995, 1997, 1999), whereas
no ice, or early ice retreat before mid-March, leads to an open-water bloom
in May or June in warm water (e.g., 1996, 1998, 2000). Zooplankton, in
particular crustacean populations, are sensitive to water temperature. In
years when the spring bloom occurs in cold water, low temperatures limit
the production of zooplankton, the survival of larval and juvenile fish,
and their recruitment. This phenomenon can be critical for the large
piscivorous fish, such as walleye pollock, Pacific cod, and arrowtooth
flounder, and additional research is needed to determine the sensitivity of
these species to water temperature fluctuations.
Climate Cycles and Trends
Natural Variability
On time scales ranging from weeks to months, semipermanent atmo-
spheric pressure patterns exert a significant influence over weather con-
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RESEARCH THEMES 55
done in a wasteful manner. The hunting of marine mammals by Alaska
Natives is unregulated, and harvest limits are placed only if a stock has
been determined to be depleted or has been listed as endangered or threat-
ened. The harvest of marine mammals by Alaska Natives is monitored for
certain species, such as Stellar sea lions and Bowhead whales, in coopera-
tion with national agencies (e.g., National Marine Fisheries Service for
Stellar sea lions) or international groups (e.g., International Whaling Com-
mission for Bowhead whales).
Marine mammals listed as endangered or threatened are the Blue
whale, the Bowhead whale, the Fin whale, the Humpback whale, the
North Pacific right whale, the Sei whale, the Sperm whale, and the Steller
sea lion (http://www.fakr.noaa.gov/protectedresources). Declines in
other species of concern include northern sea otters in the Aleutians and
Harbor seals near the Alaska Peninsula (NRC, 2003b). Subsistence harvest
has not been identified as the reason for any declines of the marine mam-
mal species except for Cook Inlet beluga, where the subsistence take has
been drastically reduced or eliminated.
Subsistence taking of marine mammals is of interest because of its
importance to the livelihood of Natives living in the coastal regions of
Alaska. The overall importance of marine mammals to the Bering Sea eco-
system is not well understood or studied, but they are expected to be a
major component of the food web and trophic interactions.
Coastal and Shelf Development
Many different types of development have direct and indirect effects
on the marine ecosystem. Development can include oil exploration,
aquaculture, mining, logging, and ports. Offshore oil exploration has been
associated with habitat degradation and alteration and with increased
levels of noise and sedimentation that can influence whale and fish migra-
tion (Alaska Department of Fish and Game, 1995). Oil exploration can
also lead to catastrophic events such as oil spills. Aquaculture is an emerg-
ing issue in Alaska. Risks of aquaculture include the escape of species;
transmission of disease or parasites; and organics, contaminant, and
pharmaceutical loadings (RaLonde, 1993). Mining can lead to increased
runoff, contaminant loading, metal mobilization, and sedimentation. The
end result of these effects can damage or eliminate essential fish habitat
and increase contaminant loads in commercial and subsistence foods. Log-
ging leads to increased sedimentation and organics loading, with effects
similar to those of mining. Ports can be localized areas of increased con-
taminants, waste discharge, and habitat degradation.
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56 ELEMENTS OF A SCIENCE PLAN FOR THE NPRB
Shipping and Invasive Species
Shipping has at least four adverse effects on populations of fish (and
shellfish) and marine mammals (Alaska Department of Fish and Game,
2002). First, species foreign to the North Pacific environment are flushed
into the ocean together with ballast water. This problem is not unique to
the North Pacific. Research is needed to understand the extent to which
these foreign species are able to survive and, if so, what adverse effects
they might have on indigenous species (NRC, 2004). Second, shipping
may pollute the marine environment through spills and waste discharge.
Harmful substances may be released with ballast water or simply thrown
overboard. Third, cruise ships visiting Alaska have been alleged to be a
nuisance on seal populations with their pups. Finally, the noise caused by
shipping may be having adverse effects for subsistence hunters by alter-
ing marine mammal migrations. The extent and impact of these poten-
tially harmful effects have to be clarified.
Contaminants
Many toxic substances released by human activities enter the marine
environment either directly through outfalls or indirectly through runoff
or the atmosphere. Contaminants that biomagnify, including mercury
and organochlorine compounds, are a particular concern because they
become concentrated in the higher levels of the food chain even in regions
remote from the source (Environmental Protection Agency, 1997). Three
primary types of risks are perceived: (1) toxicity to individual organisms,
from microbes to mammals, or to the ecosystem; (2) toxicity to humans,
especially those such as Alaskan Natives whose diet may consist predomi-
nantly of aquatic foods; and (3) contamination of fisheries resources that
affects marketability. Based on community input, there is much concern
in Alaska about the contamination of food that is important for the sub-
sistence economy, especially seal and whale fat and shellfish. There are
currently few monitoring programs, although Macdonald et al. (2003a,b)
and Stein and Macdonald (2003) review marine contaminants in the NPRB
study region and discuss the importance of monitoring contaminants in
the context of physics and biology. Nonetheless, clarification of whether
or not this concern is well founded with regard to human health and the
health of the marine ecosystem is necessary.
Role of the NPRB
The science community lacks critical time series of contaminant data
collected from strategic locations for which there are good support data
for physical and biological processes. Therefore, time-series stations initi-
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RESEARCH THEMES 57
ated or supported by the NPRB could provide an exceptionally valuable
resource upon which to build contaminant time series. If the NPRB were
to fund such proposals, it should seek partnerships with organizations
whose primary interest is contaminant pathways to ensure adequate
funding for contaminant time series. Furthermore, the NPRB should con-
sider supporting sample archives by contributing samples and, possibly,
funding.
The NPRB could provide funding for temporal and spatial studies on
both targeted and nontargeted fish populations. These studies should con-
sider various age classes and the possible consequences that changes in
fish stocks may have on upper trophic levels. It is vital for the NPRB to
recognize that ecosystems are a cascade because many fish are predators
and changes in the fish assemblages will have both top-down and bottom-
up effects. Ecosystem studies examining trophic dynamics are imperative
and often require long-term monitoring. NOAA Fisheries has extensive
programs to do many of these forms of monitoring, and this is an area in
which extensive integration with existing programs is particularly
important.
The NPRB could provide funding for research on the effects of coastal
and shelf development that have potential ramifications on the marine
community in Alaska. Basic research and long-term monitoring will be
needed to determine these effects and their consequences. Many agencies
and private industries would make ideal partners for these undertakings.
The NPRB could finance research on shipping and invasive species,
including the allegedly harmful effects of shipping, such as waste dis-
charge, the introduction of species through ballast water, and disturbance
of marine mammals. Currently, little funding is going into these endeavors.
To ensure adequate support, partnerships should be sought with private
organizations and agencies.
ECONOMIC, SOCIAL, AND MANAGEMENT RESEARCH
Fisheries are of interest not only because of their effects on the marine
ecosystem and environment, but also because of their effect on the societies
in which they are embedded. Indeed, one could argue that marine eco-
systems and their fluctuations are of interest because of their effect on
human societies. Fisheries have long attracted the interest of economists
and social scientists because open access to fish stocks has undesirable
consequences, from both an economic and a biological point of view. All
important fisheries in the Northeast Pacific are now regulated in one way
or another, and much research has been devoted to how these fisheries
should be managed. There is a critical need for ecosystem-level manage-
ment rather than single-stock management of fisheries. This has been
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58 ELEMENTS OF A SCIENCE PLAN FOR THE NPRB
discussed but not implemented in the Bering Sea. This is an ongoing
endeavor; not only is the management of certain fisheries still in a state of
flux (Alaska crab fisheries, for example), but the management regimes
that have been put in place (e.g., for Alaska pollock and Alaska halibut)
have met with both praise and criticism. There is thus a need for economic
and social research to assess how well existing management regimes are
functioning, how they could eventually be improved, and what regimes
would be appropriate for those fisheries in which the management regime
is at a formative stage.
The interrelations between socioeconomic processes and exploitation
of resources are complex. Changes in the availability of resources and the
technology of extraction led to social changes, but social changes of a dif-
ferent origin can also result in changes in the exploitation of resources
and even the technology used. Research questions concern understanding
these social processes, their causes and effects, and the influence of
fisheries on marine resources. The interaction between basic and applied
or management research is sometimes direct and obvious; often, it is less
so (Box 3-1).
Understanding the Effects of Fisheries Regulations
Since the late 1980s the regulations of several fisheries in the United
States have been changed radically. Up to the individual transferable
quota (ITQ) moratorium of 1996, these changes involved putting fisheries
under ITQ management (e.g., the surf clam fishery, the wreckfish fishery,
the Alaska halibut and sablefish fisheries). These regulatory changes were
aimed primarily at increasing the economic efficiency of the fisheries in-
volved, which resulted in fewer boats and fewer people employed. Simul-
taneously, the distribution of income was affected; some people undoubt-
edly gained from the change, while others lost in absolute or relative
terms. This put an increased emphasis on distributional issues (i.e., who
gets what and how much). The Alaska halibut individual fishing quota
(IFQ) program is strongly affected by a desire not to change the distribu-
tion of income too much, with strict limits on transferability of fish quotas
and who can hold these quotas. The ITQ moratorium was partly a result
of an increasing concern about distributional issues, although other issues
were involved as well (see NRC, 1999b, for a complete synopsis).
Irrespective of the stand one may take on efficiency versus distribu-
tion, an evaluation of any program will require data on key variables,
both before and after such programs have been put in place. Many econo-
mists and social scientists in the United States are concerned that suffi-
cient data are not available. A brief discussion below provides two sets of
data that are crucial to the evaluation.
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Quantity, Value, and Cost of Fish Landings
Better management of fisheries may result in (1) larger fish catches or
(2) higher prices for the fish brought ashore (because of better treatment
at sea or a longer fishing season, making it possible to deliver to the fresh
fish market). The quantity of landings is collected or estimated routinely
for all important U.S. fisheries. Information on prices may be patchier,
especially where vertically integrated operations are involved. In verti-
cally integrated operations, the ex-vessel price of fish is a transfer price
internal to the operation but nevertheless important, because it is one of
the determinants of remuneration when the crew is paid with a share in
the value of landings rather than a fixed wage. It is likely that vertically
integrated firms would refuse to disclose information on transfer prices
for reasons of confidentiality.
Better management of fisheries is expected to lead to lower cost per
unit of fish landed, especially in fisheries controlled by an overall catch
limit but with no limit on entry or participation. Management through
ITQs or fishing cooperatives is expected to lead to fewer boats being used
in the fishery but for a longer period of time. This would reduce capital
costs. There are two opposing effects on variable costs: (1) variable costs
of boats taken out of the fishery would disappear, but (2) variable costs
for the remaining boats would incease because of a longer fishing season.
Cost data for the fleet are required to evaluate these effects. Such data are
not routinely collected in the United States. One way of obtaining such
data would be to collect the accounts and landings data of the firms
involved.
Employment and Remuneration of Crew
Reduction of overfishing seems bound to result in crew unemploy-
ment, but this could be mitigated as the fishing season becomes longer,
providing more stable employment. Less demand for crew is likely to
reduce the bargaining power of crew and lead to a lower wage. To
evaluate whether crew have been negatively impacted by a change in the
regulatory regime, data are needed on employment and crew remunera-
tion that span the periods before and after the regulatory change.
Other Economic and Social Research Issues
Fisheries-Dependent Communities
One possible consequence of a change in regulation is diversion of
fish landings and/or operations of fishing boats away from certain com-
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60 ELEMENTS OF A SCIENCE PLAN FOR THE NPRB
munities. Indeed, this is not an unlikely event if the change results in a
reduction in the fleet or in the processing capacity. Communities with few
employment alternatives other than fishing might be the losers from such
a change. To evaluate the effects of changing regulations on fisheries-
dependent communities, macro data are needed, such as the share of fish
and fish processing that accounts for the total income generation and
employment in these communities. These data must also be interpreted
carefully, because the removal of a critical industry from small communities
may initiate a decline that feeds on itself and makes such communities
unviable. Finally, such scenarios must be evaluated relative to alternative
outcomes. Fisheries-dependent communities may be up against other
obstacles, such as demand for a varied labor market and access to public
services, that small communities may have difficulty providing.
The Subsistence Economy
It appears that the subsistence economy is under stress from various
sources. In recent years there has been a substantial decline in the salmon
runs exploited by various subsistence communities in Western Alaska. At
the same time the population in the area has been growing and, generat-
ing an increasingly stronger demand on resources. These challenges seem
likely to put the social fabric in the subsistence communities under pres-
sure. The research questions emanating from this are how great a threat
this is to the subsistence economy and what are its longer-term prospects
of viability. The social science research questions flowing from this are
not just about understanding these pressures, but also about finding ways
to deal with them that would limit the undesirable side effects on the
communities involved.
There are other challenges to the subsistence economy that might
potentially cause social changes in these communities. Apparently there
is an increasing demand from recreational interests in other parts of the
state for some of the resources traditionally exploited by the subsistence
communities, although there is some uncertainty about the existence and
the seriousness of these problems, which makes research on their exist-
ence and consequences all the more relevant. This is likely to further
aggravate the problems of increasing demand for dwindling resources.
Another challenge is the increasing dependence of the subsistence
economy on a parallel cash economy. The subsistence economy is increas-
ingly dependent on vehicles, fuel, and gear that require cash purchases.
For the subsistence economy to be able to exploit modern technology, a
parallel and thriving cash economy is needed.
The subsistence economy depended in days past, and still depends,
on knowledge transmitted orally between individuals and generations.
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Much of this traditional knowledge is in danger of disappearing within a
short time, unless it is collected, systematized, and written down. This
traditional knowledge is a useful supplement to modern, quantitative
scientific knowledge because it may provide information about the past,
prior to systematic collection of scientific data. Gathering this kind of
knowledge is however, a challenging task since memories are typically
short and selective and vary in quality from one individual to another.
Finally, a social change affecting the subsistence economy and in fact
relieving the pressure on it is one associated with a rising level of educa-
tion and demand for various types of services. People in subsistence
communities with higher education have difficulties in finding work
opportunities commensurate with their education. The modern family
structure in which both spouses work outside the home also increases the
propensity to settle in larger towns or population centers that provide
more varied work opportunities and better access to services. Studying
the scale of these changes and their effects on the subsistence economy in
both economic and social terms would be a timely piece of social research
complementing, for example, research on improving health and living
conditions.
Commercial Fisheries
Commercial fisheries in Alaska face some of the same pressures that
the subsistence economy faces. Rising educational levels are likely to put
small, isolated fishing communities where fishing and fish processing is
virtually the only industry under the same kind of pressure as the sub-
sistence communities. Understanding these processes, their scale, and
their causes and effects is important, particularly because the decline of
such communities may be attributed to changes in management regimes
instead of ongoing secular changes.
One major innovation in fisheries management in Alaska has been
the community development quotas (NRC, 1999c) by which a certain por-
tion of the total catch quota is set aside for communities. Research on the
economic and social impact of these quotas seems timely. This research
could help determine how community development quotas contribute to
economic and social development, and whether they have affected the
social structures of the communities involved.
Over the last 10 years or so, major changes have occurred in the
management of Alaska fisheries; these include IFQs in the halibut fishery,
fishing cooperatives in the Alaska pollock fishery, and on the horizon, a
system of fishing and processing quotas for the crab fisheries. These inno-
vations are likely to have both economic and social effects, possibly
changing a previous balance between different interests (capital and labor,
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fishermen versus processors) in the industry. Recording and evaluating
these changes would be an integral part of an evaluation of these manage-
ment changes.
Traditional Knowledge
Traditional knowledge can provide important information about
marine ecosystems. Since it is usually acquired and developed over a
long time, in some instances centuries, traditional knowledge potentially
could extend time-series into the past and can be an additional data source
for many of the science issues discussed above. However, if scientists
hope to utilize traditional knowledge, it will be necessary to preserve that
knowledge for future use. Memorizing an oral history is a learned skill
that was taught to the present generation of elders but in many instances
has not been passed down to younger generations. Several federal agen-
cies (e.g., National Science Foundation, National Oceanic and Atmo-
spheric Administration, Minerals Management Service) have recognized
the importance of traditional knowledge and have initiated programs for
collecting this information (NRC, 2003b). The NPRB should also facilitate
the collection and use of traditional knowledge. Whereas documentation
of traditional knowledge is a broad challenge that would go beyond the
mandate of the NPRB, documentation of traditional knowledge about the
marine environment does lie within the NPRB mandate. Such documen-
tation would preserve that portion of the record and could add depth to
contemporary studies designed to understand the present state of the
region's marine ecosystem. Native communities, the holders of traditional
knowledge, should be an integral part of this documentation process.
The use and integration of traditional knowledge with information
produced by modern scientific methods has seldom been done well.
Sharing expertise from the two very different approaches requires special
and diligent effort. Fortunately, a number of organizations are committed
to assisting researchers in utilizing traditional knowledge, and it is sug-
gested that the NPRB encourage scientists to link with these groups where
appropriate; examples include the Alaska Native Science Commission
http://www.nativescience.org/index.html and the Alaska Native Knowl-
edge Network http://www.ankn.uaf.edu/index.html.
Scientists are beginning to work with indigenous people to incorpo-
rate their accounts of recent climatic events. These studies are finding that
the climatic variations observed by indigenous people and by scientific
observation are, for the most part, in good accord (Krupnik and Jolly,
2003). Traditional knowledge can provide observations of change and
processes, the identification of particularly important locations, and times
of life history events. Traditional information can often form the basis for
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hypothesis design and testing, and it can be used to help set science
priorities for the NPRB if local insights are incorporated into the planning
process. As Glaesel and Simonitsch (2001) note,
[T]here is an inherent flaw in calling for more participatory forms of
management when the specific goals are predetermined. Under such
conditions local people's role in the management process necessarily
remains prescribed and largely symbolic.
Additionally, local knowledge of a region should be used to provide
practical insight into the solution of logistical problems such as study
design and vessel and equipment choice. Those living in the area will
have a much better understanding of local conditions, logistical chal-
lenges, and workable solutions.
Role of the NPRB
The NPRB could gather and systematize social information on an
ongoing, or long-term, routine basis. This is desirable because some of
the effects of recent and pending regulatory changes in the fisheries of the
North Pacific may have long-term consequences and also because deci-
sions about future regulatory changes would benefit from a long time
series of information covering the period before the new regime was put
into effect.
The NPRB could finance clearly targeted social research projects with
the goal of understanding the processes of social change, especially in
small and isolated subsistence and commercial fishing communities.
Understanding the causes, scale, and effects of these processes is impor-
tant because they will typically have some undesirable effects, and there
will undoubtedly be a perceived need to do something about them. How-
ever, if these processes are insufficiently understood--particularly, if they
are ascribed to irrelevant causes--attempts to affect them will miss their
mark and probably be self-defeating.
The NPRB should seek proposals whose goal is to preserve those
aspects of traditional knowledge that are relevant to its goals and should
encourage the incorporation of traditional knowledge into research plan-
ning and hypothesis development.
FORECASTING AND RESPONDING TO CHANGE
Forecasting change in ecosystem structure and functioning depends
on the ability to forecast climate change, but this alone will not be suffi-
cient. Ecosystems, viewed as complex systems, have an inherent indeter-
minacy beyond physics and pose an even greater challenge with respect
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to forecasting. Climate prediction on its own is limited not only by model
prediction skills (i.e., an ability to represent the real world), but also by
the limits of climate predictability, which possibly exist in this highly non-
linear system. Understanding these limits is as important to that effort as
increasing model fidelity.
Recent advances in climate model physics and in high-performance
computer technology may soon allow some of the above issues to be
addressed. New components of a climate model, including ocean, sea ice,
and atmospheric modules, are being developed, that can take advantage
of modern computer power to improve model skill in simulating past and
predicting future climate changes. Ensemble model simulations of climate
change using different models or a single model but with different initial
conditions may provide new insights into the limits of climate predict-
ability.
Forecasts of climate variations are carried out in two distinctly differ-
ent ways, using either statistical or numerical modeling techniques. The
statistical approach analyzes time-series sets that describe previous vari-
ability as predictors to forecast the climatic state several months to a year
in the future. This method is used to predict climate events such as the
number of Atlantic hurricanes in a given year, the onset of El Niño, and
Beaufort Sea summer ice conditions. The numerical modeling approach
uses coupled ocean-atmosphere models to predict climate variability. The
model is initialized with the best possible representation of the ocean-
atmosphere state and then allowed to run forward freely. The skill asso-
ciated with both modeling approaches continues to increase rapidly, with
improvements in theory and computational performance. Both approaches
will likely be essential for forecasting change in ecosystem structure and
function in the NPRB region.
Large-scale ecological models generally are even less well developed
than physical modules, particularly for northern polar regions. Most of
the progress to date has been in simulating dynamics of phytoplankton
and to a lesser extent zooplankton. More complex trophic couplings are
not known well enough to simulate statistically or numerically. Inter-
disciplinary process studies are required to fill in the current data gaps so
that these systems can be described more fully and their response to envi-
ronmental changes can be better predicted.
Requirements and Limitations
Requirements for the success of the statistical approach are precise
and sufficient measurements for developing robust models. Require-
ments for the success of the numerical modeling approach are sufficient
measurements to represent the initial state adequately, a good knowledge
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of the dynamics of the system to be predicted, and sufficient computer
resources to perform increasingly complex computations. With regard to
marine ecosystems, none of these requirements are adequately met.
Therefore the ability to forecast ecosystem changes is currently limited.
Role of the NPRB
Develop a Long-Term Database
A long-term program of environmental measurements that are useful
for statistical and numerical forecasting of climate and ecosystem state
could be an enduring legacy of the NPRB science program. In addition,
the NPRB can play an important role in the integration and synthesis of
historical and modern observational data. These data will be critical to the
development of models for retrospective understanding of climate and
ecosystem variability in the recent past and for prediction (or to deter-
mine the limits of predictability) in the near future.
Develop Models
The NPRB could encourage the development and use of marine eco-
system and climate models suitable for studying local processes, feed-
backs, and the large-scale ecosystem response to short- and long-term
climate change, respectively. These should include statistical models and
dynamic nested models, in which high-resolution regional models are
embedded in coarser-resolution models of a larger geographic area.
With regard to the last item, models that allow integration and syn-
thesis of observations are now an integral part of many observational
programs, especially those (like the NPRB's) that are limited by temporal
(e.g., sea-ice cover), spatial (covering large areas), and geographical access
(e.g., political boundaries) or by the availability of funds.
Representative terms from entire chapter:
arctic ocean
