[Federal Register Volume 79, Number 63 (Wednesday, April 2, 2014)]
[Notices]
[Pages 18518-18526]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2014-07368]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
[Docket No. 0810061318-4050-02]
RIN 0648 -XL10
Endangered and Threatened Wildlife and Plants; Endangered Species
Act Listing Determination for Southeast Alaska Pacific Herring
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.
ACTION: Notice of a listing determination; availability of status
review report.
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SUMMARY: We, NMFS, have completed a comprehensive status review of the
Southeast Alaska Distinct Population Segment (DPS) of Pacific herring
(Clupea pallasii) under the Endangered Species Act (ESA). Based upon
the best scientific and commercial data available, we conclude that
listing the Southeast Alaska DPS of Pacific herring is not warranted at
this time. We also announce the availability of the status review
report.
DATES: This finding is made as of April 2, 2014.
ADDRESSES: The Status Review of Southeast Alaska Pacific Herring,
Extinction Risk Analysis report, as well as this listing determination,
can be obtained via the internet at http://alaskafisheries.noaa.gov/ or
from Kate Savage, NMFS Alaska Region, Protected Resources Division,
P.O. Box 21668, Juneau, AK 99802-1668.
FOR FURTHER INFORMATION CONTACT: Kate Savage, NMFS Alaska Region, (907)
586-7312; Jon Kurland, NMFS Alaska Region, (907) 586-7638; or Dwayne
Meadows, NMFS Office of Protected Resources, (301) 427-8403.
SUPPLEMENTARY INFORMATION:
Background
On April 2, 2007, we received a petition from the Juneau Group of
the Sierra Club to list the Lynn Canal stock of Pacific herring as a
threatened or endangered species under the ESA and to designate
critical habitat. We determined that the petition presented substantial
information indicating that the petitioned action may be warranted and
published a 90-day finding (72 FR51619; September 10, 2007) that
initiated a status review. We convened a Biological Review Team (BRT)
composed of Federal scientists with expertise in Pacific herring
biology and ecology to conduct the status review. The BRT reviewed
existing research and information, including both published and
unpublished literature and data on herring stocks throughout the
eastern North Pacific. Based on information contained in the status
review report produced by the BRT, we published a finding (73 FR 19824;
April 11, 2008) that listing the Lynn Canal Pacific herring as
threatened or endangered under the ESA was not warranted because the
population does not constitute a listable entity (species, subspecies,
or DPS) under the ESA. We concluded that the Lynn Canal Pacific herring
stock is part of a larger Southeast Alaska DPS, extending from Dixon
Entrance in the south, where the Southeast Alaska stock is genetically
distinguished from the British Columbia stock, to Cape Fairweather and
Icy Point in the north, where the stock is limited by physical and
ecological barriers. We further concluded that the DPS to which Lynn
Canal Pacific herring belong should be considered a candidate species
under the ESA. Consequently, we initiated a status review of the
Southeast Alaska DPS and published a request for information, data, and
comments pertinent to a risk assessment (73 FR 66031; November 6,
2008).
Listing Determinations Under the ESA
Two key tasks are associated with conducting an ESA status review.
The first is to identify the taxonomic group under consideration, and
the second is to conduct an extinction risk assessment to determine
whether the species, subspecies, or DPS is threatened or endangered.
Section 3 of the ESA defines a ``species'' as ``any subspecies of
fish or wildlife or plants, and any distinct population segment of any
species of vertebrate fish or wildlife which interbreeds when mature.''
Section 3 of the ESA further defines an endangered species as ``any
species which is in danger of extinction throughout all or a
significant portion of its range'' and a threatened species as one
``which is likely to become an endangered species within the
foreseeable future throughout all or a significant portion of its
range.'' Thus, we interpret an ``endangered species'' to be one that is
presently in danger of extinction. A ``threatened species,'' on the
other hand, is not presently in danger of extinction, but is likely to
become so in the foreseeable future (that is, at a later time). In
other words, the primary statutory difference between a threatened and
endangered species is the timing of when a species may be in danger of
extinction, either presently (endangered) or in the foreseeable future
(threatened). The determination of whether a species should be listed
as endangered or threatened must be based solely on the best scientific
and commercial data available.
NMFS and the U.S. Fish and Wildlife Service (USFWS) have a joint
policy on recognizing distinct vertebrate population segments to
outline the principles for identifying and managing a DPS under the ESA
(61 FR 47222; February 7, 1996). Under the DPS policy, both the
discreteness and significance of a population segment in relation to
the remainder of the species to which it belongs must be evaluated. A
population segment of a vertebrate species may be considered discrete
if it satisfies any one of the following conditions:
(1) It is markedly separated from other populations of the same
taxon as a consequence of physical, physiological, ecological, or
behavioral factors. Quantitative measures of genetic or morphological
discontinuity may provide evidence of this separation.
(2) It is delimited by international governmental boundaries within
which differences in control of exploitation, management of habitat,
conservation status, or regulatory mechanisms exist that are
significant in light of section 4(a)(1)(D) of the Act.
If a population segment is discrete, we will evaluate its
biological and ecological significance in light of Congressional
guidance (see Senate Report 151, 96th Congress, 1st Session) that the
authority to list DPSs be used ``sparingly'' while encouraging the
conservation of genetic diversity. The significance consideration may
include, but is not limited to, the following:
(1) Persistence of the discrete population segment in an ecological
setting unusual or unique for the taxon,
(2) Evidence that loss of the discrete population segment would
result in a significant gap in the range of a taxon,
(3) Evidence that the discrete population segment represents the
only surviving natural occurrence of a taxon that may be more abundant
elsewhere as an introduced population outside its historic range, or
(4) Evidence that the discrete population segment differs markedly
from other populations of the species in its genetic characteristics.
[[Page 18519]]
Following the delineation of the species, the extinction risk
assessment must be of sufficient scope and depth for us to determine
whether the species is in danger of extinction or likely to become so
in the foreseeable future throughout all or a significant portion of
its range. Based on the information below, the foreseeable future in
this case was determined to be approximately 3 generations or about 30
years for herring, as equivalent to the time frame over which
predictions in making determinations about the future conservation
status of the species can be reasonable relied upon (NMFS 2013). There
are many possible quantitative and qualitative approaches to assessing
extinction risk. Regardless of the approach, an extinction risk
analysis for potential ESA listing must include an analysis of whether
a species is threatened or endangered because of any one or a
combination of the following ESA section 4(a)(1) factors: The present
or threatened destruction, modification, or curtailment of its habitat
or range; overutilization for commercial, recreational, scientific, or
educational purposes; disease or predation; inadequacy of existing
regulatory mechanisms; or other natural or human-made factors affecting
its continued existence. An extinction risk analysis also usually
includes an analysis of demographic trends, if available, of the
species relative to identified threats. Threats to a species' long-term
persistence are manifested demographically as trends in abundance,
productivity, spatial structure, diversity, and/or other relevant
factors. Trends in these parameters may provide the most direct indices
or proxies of extinction risk.
On December 16, 2004, the Office of Management and Budget (OMB)
issued a Final Information Quality Bulletin for Peer Review (Bulletin)
establishing minimum peer review standards, a transparent process for
public disclosure of peer review planning, and opportunities for public
participation. The OMB Bulletin, implemented under the Information
Quality Act (Public Law 106-554), is intended to enhance the quality
and credibility of scientific information disseminated by the Federal
Government, and applies to influential and highly influential
scientific information disseminated on or after June 16, 2005. The
status review for Pacific herring qualifies as influential scientific
information. To satisfy our requirements under the OMB Bulletin, we
obtained independent peer review of the status review from three peer
reviewers. Their comments were incorporated in the final version of the
status review report.
Species Information and Delineation
We developed a status review report for the Southeast Alaska DPS of
Pacific herring. The report (NMFS, 2014) is a compilation of the best
scientific and commercial data available concerning the status of
Pacific herring in Southeast Alaska, including identification and
assessment of the past, present, and foreseeable threats to the
species, as well as taxonomy, life history, and ecology of Pacific
herring. Numerous fishery scientists and managers provided information
that aided in preparation of the status review report. Below we
summarize the key life history and species information from the status
review report (NMFS, 2014).
Pacific herring are a small, mobile, planktivorous forage fish
belonging to the Clupeidae family. The range of Pacific herring
includes coastal regions along the eastern and western Pacific, with a
northerly range extending into the Beaufort Sea and Arctic Ocean (Hart,
1973; Mecklenburg et al., 2002). Pacific herring are also found in many
large and small aggregations, or schooling groups, throughout the
Alexander Archipelago of Alaska. Habitat requirements for the species
are diverse and partially a function of life stage. The most visible,
and crucial, event in the herring life cycle is spawning, which
generally occurs at predictable times (typically in the spring/early
summer in Southeast Alaska) and in predictable locations (Hay and
Outram, 1981). During spawning events, adult herring congregate along
shorelines protected from ocean surf. Within these established spawning
grounds, female herring deposit eggs onto a variety of different
substrate types, including eelgrass, kelp, rockweed and other seaweed
as well as on inorganic material such as rocks or pilings (Hart, 1973).
Male herring then fertilize the eggs externally.
Following the spawning event, eggs usually hatch to a larval stage
in about 2-3 weeks, depending upon the water temperature (Outram,
1955). Within a week of hatching, larvae must begin feeding to ensure
survival, although they may be passively advected away from feeding
areas (McGurk, 1984). Once the larvae become nektonic (free-swimming),
they move to favorable habitats where they metamorphose into juveniles
and form schools. Preferred habitat for adult and juvenile Pacific
herring includes a variety of nearshore habitat types, such as bedrock
outcrops, eelgrass, kelps, and sand-gravel beaches (Johnson and
Thedinga, 2005). Juveniles begin recruiting to the adult population at
age 3 (Williams and Quinn, 2000; Hay et al., 2001). Adults live in
schools that undergo diurnal and seasonal movements. Seasonally, adult
herring tend to migrate between summer feeding areas on shelf waters to
overwintering areas, often in deep, protected nearshore water, and then
to spawning locations (Hay et al., 2001).
The evidence for the delineation of the Southeast Alaska Pacific
herring DPS was presented in the Status Review of Lynn Canal Herring
(Carls et al., 2008), which we made available for public review on
April 11, 2008 (73 FR 19824). Several sources of data were considered
in evaluating the DPS structure and discreteness of Southeast Alaska
herring populations. This information included: Geographic variability
in life-history characteristics, physiology, and morphology; ecosystem
and oceanographic conditions; spawn timing and locations, tagging and
recapture studies that would indicate the extent of migration and
intermingling among stocks; and studies of genetic differentiation
among stocks that would suggest some degree of reproductive isolation.
After analyzing the best available scientific and commercial
information, the Southeast Alaska DPS was determined to extend from
Dixon Entrance northward to Cape Fairweather and Icy Point and includes
all Pacific herring stocks in Southeast Alaska.
The delineation of the southern boundary was based on genetic
differences between herring in Southeast Alaska and those in British
Columbia, as well as differences in recruitment and average weight-at-
age, parasitism, spawn timing and locations, and the results of tagging
studies conducted in British Columbia (Carls et al., 2008). The
northern boundary is defined by physical and ecological features that
create migratory barriers, as well as large stretches of exposed ocean
beaches that are devoid of spawning and rearing habitats.
Given the large scope of this geographic area and the large number
of stocks found throughout Southeast Alaska, we determined that the
Southeast Alaska Pacific herring population is significant to the taxon
as a whole. Specifically, the Southeast population exists in a unique
ecological setting, and the extirpation of this population of Pacific
herring would result in a significant gap in the range of the taxon
(Carls et al., 2008). The status review report (NMFS, 2014) found no
new information to change the basis for those conclusions.
[[Page 18520]]
The BRT also recognized the possibility that there may be
subdivisions within the Southeast Alaska DPS. Data released since the
2008 DPS determination may support this possibility. A study assessing
whether the Lynn Canal stock is genetically distinct from other eastern
Gulf of Alaska herring found that the genetic structure of samples from
the fjord system of Berners Bay and Lynn Canal was significantly
different from samples taken from Sitka Sound/outer coast Pacific
herring (Wildes et al., 2011). Hobart Bay, considered an interior water
body on a main waterway bisecting Southeast Alaska, shared genetic
features of both areas, while Hoonah Sound herring were found to be
genetically distinct from Lynn Canal and Berners Bay herring (Wildes et
al., 2011). Their fatty acid signature also differed from other areas
tested in Southeast Alaska (Otis et al., 2010). Although Wildes et al.
(2011) recommended a larger, multi-year sampling, results also showed
genetic differences between samples from Southeast Alaska and Prince
William Sound. Another study using microsatellites to assess the
genetic population structure of Pacific herring in British Columbia and
adjacent regions found differentiation between herring that spawned in
more inland waters and those that spawned in more seaward locations
(Beacham et al., 2008); a difference possibly related to life history,
because resident herring spawn in mainland inlets and adjacent inland
waterways, while migratory herring spawn in coastal areas and move to
offshore summer feeding grounds. While the same study found
distinctions between herring of California, Washington, and subgroups
of herring in British Columbia, primarily due to spawn timing and
geographic isolation, less differentiation existed between Southeast
Alaska and British Columbia. Very little differentiation was noted
between the Southeast Alaska herring stocks, which included: (1)
Combined samples from Mary Island and Kirk Point; (2) combined samples
from north and south Sitka Sound; and (3) samples from Seymour Canal
(Beacham et al., 2008).
Although these studies indicate that environmental differences may
have reduced the gene flow in some regions of southeast Alaska, and
that corresponding adaptations have occurred in herring in outer
coastal as compared to interior waterways, the data do not contradict
the 2008 DPS delineation (NMFS, 2014).
Summary of ESA Section 4(a)(1) Factors Affecting the Southeast Alaska
DPS of Pacific Herring
The following sections discuss threats to Southeast Alaskan herring
under each of the five factors specified in Section 4(a)(1) of the ESA
and 50 CFR 424.11(d), with more detailed discussion included in Section
6 of the status review report (NMFS, 2014). Threats were assessed
singly, collectively and also relative to herring abundance, growth
rate/productivity, spatial structure/connectivity, and diversity.
Present or Threatened Destruction, Modification, or Curtailment of
Habitat or Range
In Southeast Alaska, there does not appear to be a single acute
threat to Pacific herring habitat. Instead, the localized abundance of
herring may be affected by modifications in the immediate environment,
including changes associated with increasing anthropogenic activity
such as shoreline development, pollution, or marine traffic and noise.
While no large projects currently pose a substantial threat to herring
habitat, it is clear that the cumulative effect of chronic habitat
alteration may decrease habitat suitability for herring over time.
Coastal development activities in Southeast Alaska have increased with
human population growth and may have contributed to changes in regional
stocks of herring. At present, both the resident and seasonal non-
resident human population of Southeast Alaska is increasing, with the
latter primarily through growth in the cruise ship industry (ADCCED,
2011). These vessels are authorized to discharge various amounts of
waste water depending upon the ship size and location (ADEC, 2010),
though specific effects from such discharges on herring are unknown.
Other vessels such as Alaska Marine Highway ferries, dry freight
barges, freight cargo barges, as well as boats fishing for herring and
other species also contribute to marine traffic and noise in Southeast
Alaskan waters (Nuka, 2012). However, while herring have been
documented to respond to vessel movement and noise (Schwarz and Greer,
1984; Misund et al., 1996; Wilson and Dill, 2002), the extent to which
vessel traffic affects herring populations in Southeast Alaska has not
been documented. Another method by which herring habitat may be
modified is through the introduction of invasive species, such as the
colonial tunicate Didemnum vexillum in waters around Sitka, which has
the potential to smother herring spawning habitat (Valentine et al.,
2007; Morris et al., 2009; L. Shaw, pers. comm., NMFS).
Defining the consequences of habitat modification for herring
populations is challenging because sufficient information is not
available to understand the reliance of herring on particular habitats
or the cumulative effects of habitat loss and degradation. It is
probable that a synergy of both identified and unidentified factors
link herring biology and the surrounding environment, and habitat
modification could eventually lead to changes in herring populations.
The decline of herring at Auke Bay, for example, was probably a result
of multiple stressors, perhaps including permanent changes in the
shoreline due to coastal development and consequent changes in water
quality and substrate (NMFS, 2014). Conversely, herring abundance in
Sitka Sound, which has also experienced growth in shoreline activity
and associated infrastructure, has shown an increasing trend for
several decades (NMFS, 2014).
In summary, the destruction, modification, or curtailment of
habitat or range may have affected Southeast Alaska Pacific herring
over time and may continue to do so as coastal development progresses,
although the magnitude of such effects is unclear. The vast majority of
shoreline and spawning habitat in Southeast Alaska is sparsely
developed and is likely to remain so for the foreseeable future,
although incremental losses of herring habitat will likely continue. We
conclude that based on the available information, habitat loss and
degradation are not likely to cause the Southeast Alaska Pacific
herring to become in danger of extinction within the foreseeable future
throughout all or a significant portion of its range (see below for
consideration of the significant portion of its range issue).
Over-Utilization of the Species for Commercial, Recreational,
Scientific or Educational Purposes
The biggest direct anthropogenic influence on Southeast Alaska
Pacific herring for the past century has been commercial fishing.
Large-scale commercial fishing for herring in Southeast Alaska began
predominantly with the reduction fishery (a fishery that reduces the
catch into meal or oil) in the early 1900s, which continued until the
1960s (Reid, 1972; Larson et al., 2000). Throughout this time,
technological improvements and increased efficiency of the fishery led
to concerns about overexploitation, with the consequent establishment
of catch limits (Rounsefell, 1930; Reid, 1971). In the
[[Page 18521]]
1960s, the volume of biomass removed by the reduction industry was
surpassed by the spawn-on-kelp fishery (the harvest of herring eggs
deposited on vegetation), which was then eventually surpassed by the
sac roe (egg) fishery (Pritchett and Hebert, 2008). Currently, the sac
roe fishery accounts for over 90 percent of all herring harvested in
Southeast Alaska. For the 2010-2011 season, for example, the total
regional commercial harvest of herring was 23,805 tons, which included
19,778 tons harvested in the sac roe fishery (Hebert, 2011).
In the status review report, data collected from the Alaska
Department of Fish and Game (ADF&G) commercial herring fisheries since
1980 was evaluated using a variety of fishery and biological reference
points as indices to define or indicate overfishing. These include:
(1) The ratio of fishing mortality to natural mortality. A ratio of
fishing mortality to natural mortality less than or equal to 0.67 has
been associated with sustainable fisheries (Patterson, 1992; Pikitch et
al., 2012). Since the 1980s, available data from Sitka Sound, Seymour
Canal, and Craig indicate that this ratio remained less than or equal
to 0.67 over 90 percent of the time.
(2) Abundance relative to threshold. Overfishing may be defined as
harvest levels that drive abundance below a prescribed threshold (Quinn
et al., 1990; Rosenberg, 2009; NMFS, 2009). Since 1980, the percentage
of managed Pacific herring stocks with estimated biomass above
threshold levels has either remained consistent or increased.
(3) Harvest levels relative to the Guideline Harvest Level (GHL)
and exploitation rates. GHLs are benchmark levels of allowable harvest.
While it is not uncommon for harvest levels to exceed the GHL, on
average, harvest levels have been fairly close to the GHL. Furthermore,
exceeding the GHL does not generally lead to an exploitation rate that
is greater than the maximum exploitation rate set at 20 percent.
Historically, exploitation rates for both the harvest in Sitka Sound
and the combined harvest of other stocks have been substantially lower
than the 20 percent rate. Because forecast estimates of stock abundance
used to set the GHL are typically lower then hindcast estimates of
actual abundance (S. Dressel, personal communication, ADF&G, 5/2/2012),
the GHL and subsequent exploitation rates tend to be conservative.
Harvest levels over 20 percent, which have generally been due to
hindcast estimates which were lower than forecast estimates, have
occurred rarely throughout the Southeast Alaska DPS (NMFS, 2014).
(4) Trends in abundance. Based on ADF&G data since the 1980s, the
combined biomass of Southeast Alaska managed herring has been
increasing, with Sitka Sound herring markedly influencing the positive
rate of growth. Estimates of the combined biomass ranged from a low of
approximately 45,000 tons of herring in 1995 to 253,000 tons in 2011.
Individual aggregations within the DPS have either increased or
fluctuated, but are not generally declining.
(5) Recruitment. An increasing trend in combined recruitment of
immature and mature age-3 herring is apparent in Sitka Sound and
Seymour Canal data available since 1980. According to data available
since 1988, the combined number of immature and mature age-3 herring
being recruited into the Craig stock has been decreasing slightly from
approximately 750 million fish in 1988 to 550 million fish in 2010
(NMFS, 2014).
(6) Size-based Indicators. Size-based indicators, such as age,
length, and weight, may be used as indices for overexploitation
(Rickman et al., 2000; Longhurst, 2002; Hsieh et al., 2006; 2008;
Anderson et al., 2008; Perry, 2010). There is no evidence under current
management that herring in Southeast Alaska are exhibiting age
truncation associated with depletion. Maximum length and weight has
increased in Sitka herring, while slightly decreasing in other combined
stocks. No marked trends are apparent in weight-at-age or length-at-age
data from Sitka Sound or other combined stocks. While age-at-maturity
appears to be increasing over the last few decades in Seymour Canal,
modeling of Craig herring indicates a trend towards earlier maturation,
and modeling of Sitka herring indicates no change in maturity over
similar time periods.
(7) Spawning ground distribution. It is possible that the
distribution and extent of spawning grounds as well as the abundance of
herring throughout Southeast Alaska has decreased since the advent of
the reduction fishery in the early 1900s (Rounsefell, 1930; Rounsefell
and Dahlgren, 1935; Skud et al., 1959; 1960; Brock and Coiley-Kenner,
2009; Thornton et al., 2010a; 2010b). While this decline may signify
that herring are currently being managed in a depleted state, other
interpretations are equally plausible. All areas in southeast Alaska
have not been surveyed within recent history and records may not be
complete. It is also possible that human-caused mortality of large
whales, and to a lesser extent Steller sea lions, especially through
the first half of the 20th century, may have reduced predation in
Southeast Alaska enough to inflate the abundance of herring, which was
then available to the reduction fishery, meaning that that era may have
actually represented an unnaturally high level of distribution and
abundance of Pacific herring.
We conclude that overutilization is not likely creating a threat of
extinction to the Southeast Alaska Pacific herring throughout all or a
significant portion of its range within the foreseeable future.
Although overutilization has occurred in the history of commercial
herring fishing in Southeast Alaska, especially during the reduction
era, neither fishery nor biological reference points indicate that
herring in Southeast Alaska are currently being over-utilized or are in
an overfished state. Evidence may indicate that herring abundance was
historically greater and spawning locations more widespread and, under
certain circumstances, this may be a cause for concern. However, this
evidence is outweighed by (1) the potential for significant gaps in
spawning location data; (2) the impacts on herring populations
resulting from the historical decline of significant predators,
including the humpback whale and Steller sea lion; and (3) the
increasing biomass of the DPS as a whole.
Disease or Predation
Both recruitment and population abundance of Pacific herring can be
influenced by disease. Disease may significantly impact a stock or
spawning group when the population has had no previous exposure to a
disease agent and environmental factors promote the presence of disease
synergistically with other stressors. The chronic presence of disease
may also prevent full recovery following a population decline (Marty et
al., 2010). Disease occurrence may occur on a broad, metapopulation
scale given necessary predisposing conditions. However, in Southeast
Alaska disease epizootics have thus far only been reported in specific
stocks or localized areas (Meyers et al., 1986; 1999; Hershberger, 2009
from T.R. Myers, unpublished accession reports). Consequently, while
disease may currently be a periodic threat to individual herring stocks
in Southeast Alaska, there is no evidence to indicate that disease
presents a population-level threat to Southeast Alaska Pacific herring,
either now or in the foreseeable future.
Predation is a consistent source of mortality through all herring
life stages and may be the primary source of mortality for some cohorts
(McGurk,
[[Page 18522]]
1989; Stokesbury et al., 2000; 2002; Tyrell, 2008). Many different
species prey upon herring in Southeast Alaska, including marine
mammals, birds, invertebrates and piscivorous fishes. These predator-
prey relationships undergo persistent shifts and may be challenging to
characterize on temporal or spatial scales. Furthermore, accurate
trends in abundance are often not available for many bird, marine
mammal, and fish species known to prey upon herring.
Two major marine mammal predators of herring, the humpback whale
and Steller sea lion, are increasing in abundance in Southeast Alaska
and it is uncertain when these species will reach their respective
carrying capacities in the region. These marine mammal species may
contribute significantly to the natural mortality of herring. Humpback
whales in particular have been cited as potentially equivalent to a
fishery in terms of herring biomass removal and have also been cited as
causing delayed or suppressed recovery of some depleted herring stocks
(Rice et al., 2011).
Although the interactions between herring and bird species that
prey upon herring are complex, there is no evidence to suggest that
avian predation is an increasing threat to Southeast Alaska Pacific
herring.
A multitude of fish species prey upon herring. Some of these
species, such as halibut and sablefish, appear to be declining in
Southeast Alaska, while others, such as arrowtooth flounder, appear to
have increased in abundance (Guenette et al., 2006; Carroll and
Brylinsky, 2010; Hare, 2010). Salmon populations have also
significantly increased over the past several decades, including wild
runs and fish from hatcheries (Pryor et al., 2009; Duckett et al.,
2010). The direct or indirect effects of these trends in abundance on
herring biomass in Southeast Alaska is uncertain.
In summary, positive population size trends indicate that disease
and/or predation are not creating a risk of extinction for Southeast
Alaska Pacific herring, nor are they likely to do so in the foreseeable
future, throughout all or a significant portion of its range. While
disease may be a constant threat to herring stocks in Southeast Alaska,
the incidence of disease does not appear to be increasing. Predation is
a significant source of mortality throughout herring life history and
predation by marine mammals, birds, fishes and invertebrates can be a
major influence on herring abundance. Given the assumption that the
magnitude of predation increases with predator population, which does
appear to be the case with humpback whales, then at least two herring
predators, humpback whales and Steller sea lions, are likely to be
increasing the predation pressure on herring in Southeast Alaska, at
least in localized areas. However, trophic interactions, including
predation and competition, are not easily characterized. Herring
predation by some species, such as marine mammals, has been
characterized more fully than with others, such as invertebrates and
piscivorous fishes. The overall impact of the various predator species
on the abundance of Southeast Alaska herring is uncertain, but again,
we have no information to suggest it will place the herring in danger
of extinction throughout all or a significant portion of its range
within the foreseeable future.
Inadequacy of Existing Regulatory Mechanisms
Existing regulatory mechanisms offer some degree of protection for
herring and their habitat in Southeast Alaska. Temporary mechanisms
include Alaska Department of Fish & Game (ADF&G) review of projects
requiring state authorization with subsequent recommendations to avoid,
minimize, and mitigate impacts to herring (K. Kanouse, personal
communication, ADF&G), such as timing windows relative to herring
spawning events for coastal construction projects (established in
Alaska Statutes, Title 16, Chapter 05, Section 871, Protection of Fish
and Game). The Alaska Department of Environmental Conservation also
implements Water Quality Standards which may indirectly affect herring
habitat and biology (ADF&G 2010).
Existing regulatory mechanisms for fishing are in the form of
fishery management measures defining the limitations of commercial
harvest. Assessment of the effectiveness of these regulatory mechanisms
in protecting herring is limited by uncertainties in our understanding
of herring biology and ecology.
Regulations pertaining to the herring fishery are adopted by the
Alaska Board of Fisheries, after consideration of social, political,
and economic factors, as well as scientific input from ADF&G. The
current Herring Management Plan (codified in the Alaska Administrative
Code, Title 5, Chapter 27, Article 4, Section 190) gives ADF&G the
authority to:
(1) Identify stocks based upon spawning areas. ADF&G manages nine
separate spawning stocks of herring. While ADF&G considers the
incidence of fish migration between stocks to be low (S. Dressel,
personal communication, ADF&G, 5/2/2012) the movement of herring may be
a complicated function of density-dependent processes, geographic
scale, environmental conditions, and conspecific influence.
For example, a density-dependent spawning ground selection,
expanding when the population is large and contracting to the most
suitable sites at smaller population sizes, appears to be a common
trend in Pacific, Atlantic and Baltic herring (Ivshina, 2001; Norcross
and Brown, 2001). Herring may disappear en masse from previous spawning
grounds, with smaller aggregations having a higher probability of
disappearance, and potentially reappear as a result of conspecific
attraction or possibly when suitable conditions return to a vacant
habitat (Ware and Tovey, 2004).
(2) Establish a minimum spawning biomass threshold, below which
fishing will not occur. Initial thresholds were based on historical
knowledge, biologists' judgment, and/or a quantitative method involving
age-structured analysis. ADF&G set the thresholds at 25 percent of the
modeled average unfished biomass (Blankenbeckler and Larson, 1985;
Carlile, 1998a; 1998b; 2003). However, with the potential for
significant shifts in herring populations and trophic level dynamics
throughout the period of the reduction fishery and commercial whaling,
it is difficult to ascertain how accurately these adopted thresholds
reflect a historical equilibrium. In either case, given the significant
shifts in herring populations and trophic level dynamics that were
probable throughout the reduction fishery and commercial whaling, it is
possible that the adopted thresholds are not necessarily an accurate
reflection of a historical equilibrium;
(3) Assess the abundance of mature herring for each stock before
allowing fishing to occur. ADF&G mainly uses modeling, based upon data
collected from spawn deposition and other surveys, to forecast the
following year's abundance of mature herring for each stock.
Inaccuracies and uncertainties may arise from many different sources in
this process, and discrepancies have occurred in the past between
forecasted estimates and hindcast estimates, based on actual spawning
events. ADF&G relies on real-time assessment by biologists on the
fishing grounds to recognize these discrepancies and modify the fishery
accordingly.
(4) Except as provided elsewhere, allow a harvest of herring at an
exploitation rate between 10 and 20 percent of the estimated spawning
[[Page 18523]]
biomass, when that biomass is above the minimum threshold level.
Regulatory measures in place do not preclude an exploitation rate above
20 percent in certain circumstances; however, the incidence of
exploitation rates above 20 percent has been uncommon.
(5) Identify and consider sources of mortality in setting harvest
guidelines.
ADF&G uses modeling to estimate natural survival as a single
parameter averaged across the years for which age-specific data on
herring abundance are available. These survival estimates may be
adjusted or renewed according to trends that occur over time with
indices, but the model does not apportion predation and disease as
separate components of natural mortality, nor does it forecast upcoming
conditions.
(6) By emergency order, modify fishing periods to minimize
incidental mortalities during commercial fisheries. Managers are
expected to minimize incidental, non-regulated herring mortality by
assessing field conditions, recognizing potential catastrophic stock
changes as they occur, and modifying limits accordingly (Pritchett,
2008).
In summary, regulatory mechanisms that define limits of commercial
exploitation incorporate uncertainty regarding: Understanding of
herring biology, including migration, recruitment, and natural
mortality, which affects the accuracy of abundance assessment methods
relative to true abundance; the accuracy of values for historical or
baseline biomass; and the biological validity of thresholds and
exploitation rates relative to an unknown extinction threshold. It is
likely that these uncertainties are inherent in the regulatory
mechanisms of most commercial fisheries and not limited to ADF&G
management of herring in Southeast Alaska. Current regulatory
mechanisms also lack provisions for ongoing habitat protection
specifically for herring. Despite these concerns, current trends in
abundance discussed above and other demographic factors indicate that
existing regulatory measures appear sufficient. We find no indication
that an inadequacy of existing regulatory mechanisms has created a risk
of extinction for Southeast Alaska Pacific herring, or is likely to do
so within the foreseeable future, throughout all or a significant
portion of its range.
Other Natural or Man-Made Factors
Southeast Alaska Pacific herring could potentially be affected by
other natural factors, such as regime shifts, or other anthropogenic
factors, such as global climate change. Regime shifts are defined as
low frequency, high amplitude, and sometimes abrupt, changes in species
abundance, community composition, and trophic organization that occur
concurrently with physical changes in a climate system (McKinnell et
al., 2001), which have likely occurred throughout history. While regime
shifts appear to be a natural phenomenon in marine ecosystems, the
potential threat to herring lies primarily through the challenge to
stock sustainability, with trophic shifts and fishing serving as
synergistic stressors. Anthropogenic climate change is considered a
result of increased carbon dioxide emissions associated with human
activity. Possible physical outcomes include an increase in marine
temperature and ocean acidification (IPCC, 2007; Guinotte and Fabry,
2008). The effect of both regime shifts and anthropogenic climate
change are highly uncertain; much of the uncertainty is associated with
information gaps as well as a corresponding uncertainty which arises
from multiple sources:
(1) The inability to accurately predict the temporal and spatial
effects of ocean warming and acidification and the adaptability of
species to those effects.
(2) The inability to accurately predict future climate, the
difficulty of recognizing long-lived regime shifts at the time they
occur, and the likelihood that each regime shift will present a new set
of conditions (Mantua et al., 1997; Benson and Trites, 2002; Mantua and
Hare, 2002; Polovina, 2005; Mueter et al., 2007) where biological
variability may not be a linear function of decadal variations in
climate forcing (Miller and Schneider, 2000).
(3) The magnification of risks when the productivity of multiple
stocks may be affected similarly and simultaneously (Beamish and
Bouillon, 1995; Mueter et al., 2007), including changes in predator
abundance, distribution, and impact (McFarlane et al., 2001; Benson and
Trites, 2002).
(4) The unknown accuracy of management models and decisions,
including stock recruitment relationships and the assumption of a
baseline community or virgin unfished biomass (Steele 1996; Benson and
Trites 2002). In a population that is maintained at too low a level,
the effects of climate change may result in critical depensation,
whereby the population is no longer self-sustaining.
(5) The unknown accuracy of underlying assumption of a stable
equilibrium condition for a stock and ecosystem (May 1977).
(6) The inability to forecast the potential interplay of stressors
such as climate change, fishing pressure, and habitat loss on
populations (Chavez, 2003).
Traditionally, fishery management aims to maintain populations at
fixed levels with yields considered sustainable for an indefinite
period of time. However, in the face of continuing ocean change,
sustainability may be relative only to the current set of conditions so
management may be more challenging with less precise and predictable
outcomes.
In summary, both anthropogenic climate change and regime shifts are
associated with a great deal of uncertainty relating both to physical
and biological change as well as herring adaptability to change. The
threat of regime shifts lies primarily through the challenge to stock
sustainability, with trophic shifts and fishing serving as multiple,
synergistic stressors. Anthropogenic climate change includes ocean
warming and acidification, both of which have the potential to affect
herring abundance. Given the overall positive population trends for the
Southeast Alaska Pacific herring DPS, the short generation times, and
the observed resilience of the DPS (NMFS, 2014), we conclude that the
available evidence is not sufficient to indicate that other natural or
man-made factors, such as regime shifts or anthropogenic climate
change, have created a risk of extinction for Southeast Alaska Pacific
herring, or are likely to do so within the foreseeable future,
throughout all or a significant portion of its range.
Cumulative and Synergistic Effects
Pacific herring is a keystone species in Southeast Alaska, playing
a central role in marine food webs and it is also of significant
importance as a commercial and subsistence species in many communities.
While the threats addressed above have been considered separately,
herring population depletion may result from a series of compounded
threats interacting within the environment (Schweigert et al., 2010).
For example, the multiple facets of both anthropogenic climate change
and regime shifts present serious challenges to sustainable fishery
management. While natural systems have adapted to climatic changes
throughout history, the rate of climate change has accelerated as have
concurrent pressures, including fishing efficiency and habitat
modification. Variations in ocean climate can moderate herring
recruitment by alternating both predator and food abundance (Ware
1991). Similarly, disease in the ocean can increase predation and
contribute to population declines (Harvell et al., 1999; 2002). Links
have been
[[Page 18524]]
established between temperature and herring disease (Hedrick, 2003;
Gregg et al., 2011), which may then influence recruitment and adult
population abundance of herring (Marty et al., 2010). All of the
factors impacting herring, including the five factors discussed above,
may synergistically compromise resilience, yet, based on the population
trend and other data discussed above, we find no information to suggest
that the cumulative effects of these factors have created a risk of
extinction for Southeast Alaska Pacific herring, or are likely to do so
within the foreseeable future, throughout all or a significant portion
of its range.
Summary of Extinction Risk Analysis
In assessing risk, it is important to include both qualitative and
quantitative information. The threats section of the status review
report, summarized above, supplied qualitative information on potential
risks to Southeast Alaska herring. A quantitative assessment was then
made through a risk matrix method, as described in detail by Wainright
and Kope (1999). This method was used to organize and summarize the
professional judgment of an Extinction Risk Assessment (ERA) team
composed of a panel of four knowledgeable scientists with expertise in
Pacific herring biology and ecology. In the risk matrix approach, the
ERA team assessed the condition of Southeast Alaska herring populations
and summarized the species status according to the following
demographic risk criteria: Abundance, growth rate/productivity, spatial
structure/connectivity, and diversity as well as other modifying
factors. These viability criteria, outlined in McElhany et al. (2000),
reflect concepts that are well-founded in conservation biology and that
individually and collectively provide strong indicators of extinction
risk. After reviewing all the relevant commercial and biological data
supplied in the threats section, the ERA team used these criteria to
estimate the extinction risk of the Southeast Alaska DPS of Pacific
herring based on current demographic risks. The team scored each
criterion on a scale of 1 (no or very low risk of extinction) to 5
(very high risk of extinction) and team members offered their best
professional judgment regarding population status and extinction risks.
The ERA team scores for abundance, growth rate/productivity,
diversity, and other modifying factors ranged from 1 to 2 with a modal
and median score of 1. A score of 1 means that it is unlikely that this
factor contributes significantly to risk of extinction, either by
itself or in combination with other factors. A score of 2 means that it
is unlikely that this factor contributes significantly to risk of
extinction by itself, but some concern that it may, in combination with
other factors.
The ERA team agreed that between 1980 and 2011, the period for
which consistent data is available, the DPS has been demonstrating a
positive trend in abundance as indicated by changes in the combined
biomass of the nine ADF&G managed stocks as described above. Individual
aggregations within the DPS have either increased or fluctuated, but
are not generally declining.
The team was also in general agreement that the DPS is exhibiting
positive trends in growth rate and productivity. Based on modeled
estimates of recruitment and size-based parameters discussed above,
productivity appears to be above replacement for assessed Southeast
Alaska aggregations. However, the potential for periods of low
recruitment that may occur when conditions do not support rapid
population increases was a concern.
Although the ERA team agreed that it was unlikely that the DPS is
at risk of extinction due to changes in spatial structure/connectivity,
the team was slightly less certain in characterizing this demographic
risk. ERA team scores for the spatial structure/connectivity of the DPS
ranged from 1 to 3, with a modal score of 1 and a median score of 1.5.
A score of 1 means that it is unlikely that spatial structure/
connectivity contributes significantly to risk of extinction, either by
itself or in combination with other factors. A score of 3 represents a
moderate risk, which means that it is likely that spatial structure/
connectivity in combination with other factors contributes
significantly to risk of extinction. A DPS may be at moderate risk of
extinction due to declining trends in spatial structure/connectivity
and current threats that inhibit the reversal of these trends. While
herring in the Southeast Alaska DPS are widespread, there is some
concern relative to the importance of current versus historical
patterns as herring spawning locations do not appear to be as
widespread as they once were. Furthermore, several spawning stocks are
concentrated near urban areas, and habitat constriction is a
possibility. However, while urbanization is more likely to destroy
rather than create herring habitat, it is also probable that many
suitable, unused spawning locations currently exist. Furthermore, while
the spatial structure among different life history stages of Pacific
herring in Southeast Alaska is not well defined, evidence suggests
there is some intermixing among populations, which may serve to
maintain the viability of each (Wildes et al., 2011). There is also
little evidence to suggest the existence of a critical source
population or that migration among stocks is unidirectional, whereby
the viability of a single population or stock determines the viability
of multiple stocks or populations. Although local spawning aggregations
may periodically exhibit low levels of biomass and abundance, these
aggregations appear to rebuild in time, possibly due to immigration
from other spawning aggregations. There are also indications of
intermingling on a broader scale. Fish from Sitka Sound appear to be
more similar to herring in Prince William Sound rather than herring in
the inside waters of northern southeast Alaska, suggesting that when
the migratory stocks on the outer coast move offshore to feed in the
summer, there could be some dispersal or connectivity (Wildes et al.,
2011). On the southern border, there are spawning stocks of herring in
relatively close proximity and the coastline is comprised of herring
habitat, including many protected bays and passageways. While natural
rates of dispersal are unknown, dispersal is also possible to the
south.
The ERA team scores for current diversity ranged from 1 to 2 with a
modal and median score of 1. While not all spawning aggregations are
monitored, there is currently no evidence to suggest a substantial
change or loss of variation in life-history traits, population
demography, morphology, behavior or genetic characteristics.
With respect to relevant modifying factors, ERA team scores also
ranged from 1 to 2 with a modal and median score of 1. The team cited a
number of relevant modifying factors. While herring are considered
resilient, low recruitment, likely stemming from infrequent conditions
that support rapid population increases, was a consideration. The
potential for increased disease prevalence with herring pounds was also
of concern as was site fidelity in areas of no habitat protection and
increased urbanization and development.
To inform our consideration of threats to Southeast Alaska Pacific
herring under section 4(a)(1) of the ESA (as discussed above), the ERA
team also completed a threats assessment by scoring the severity of
current threats to the DPS as well as predicting whether each threat
will increase, decrease, or stay the same in the foreseeable future.
[[Page 18525]]
Based on the information provided in the status review document, the
major categories of threats as described by section 4(a)(1) were
further subdivided and quantitative assessments made on the following
topics: predation, disease, shoreline modification/urbanization,
invasive species, pollution, marine traffic and noise, habitat
protection, anthropogenic climate change, regime shifts, commercial
fishery regulations, fishery, fishery reference points and biological
reference points.
ERA team scores for all threats to the DPS ranged from 1 to 3, with
both modal and median scores between 1 and 2.5. A score of 1 signifies
no or very low risk, meaning that it is unlikely the evaluated factor
contributes significantly to risk of extinction, either by itself or in
combination with other factors. A score of 2 represents low risk, which
means that it is unlikely that this factor contributes significantly to
risk of extinction by itself, but there is some concern that it may in
combination with other factors. A score of 3 represents a moderate
risk, which means that it is likely that this factor in combination
with others contributes significantly to risk of extinction. The ERA
team assigned greatest risk to habitat protection followed by
predation, shoreline modification, and commercial fishery regulations.
All threats had a low to moderate (habitat protection, predation) or
low (shoreline modification, commercial fishery regulations) median and
modal scores with a range from no/very low risk to moderate risk. The
ERA team was concerned with the legal protection of spawning and
nursery habitats, both currently and in the foreseeable future,
especially relative to increased urbanization and other stressors
associated with human activity, and noted that no such specific
regulatory protections currently exist. The ERA team recognized that
populations of several large predators, and consequently potential
impacts on herring, are increasing, but considered it likely that prey
bases would shift before local extinction could occur. The ERA team
also expressed concern about the probability of increased disease
prevalence with herring pounds (enclosures where live herring may be
held before harvesting).
The ERA team used the accumulated information to determine the DPS'
overall level of extinction risk through a final scoring exercise that
included the ability for each team member to express uncertainty
through the distribution of 10 ``likelihood point'' votes. They used
the same 5 category risk scale as above. The team assigned 67.5 percent
of the likelihood points to the ``no/low'' level of extinction risk,
meaning that it was considered unlikely that the DPS is at risk of
extinction due to projected threats or trends in abundance,
productivity, spatial structure, or diversity. Thirty percent of the
points were put in the ``low'' risk of extinction category and 2.5
percent (1 vote) was placed in the moderate risk category.
Based on all of the considerations described above, the ERA team
concluded that the Southeast Alaska DPS of Pacific herring is not
currently at risk of extinction throughout its range, nor is it likely
to become so within the foreseeable future. We concur with the findings
of the ERA team.
A final task included considering whether the Southeast Alaska DPS
of Pacific herring is at risk of extinction throughout a significant
portion of its range. NMFS and USFWS published a draft policy to
clarify the interpretation of the phrase ``significant portion of the
range'' in the ESA definitions of ``threatened'' and ``endangered'' (76
FR 76987; December 9, 2011). The draft policy consists of the following
four components:
(1) If a species is found to be endangered or threatened in only a
significant portion of its range, then the entire species would be
listed as endangered or threatened.
(2) The range of a species is ``significant'' if its contribution
to the viability of the species is so important that, without that
portion, the species would be in danger of extinction.
(3) The range of a species is considered to be the general
geographical area within which the species, including all or any part
of its life cycle, can be found at the time the status determination is
being made.
(4) If a species is not endangered or threatened throughout all its
range but is endangered or threatened within a significant portion of
the range, and the population in that significant portion is a valid
DPS, we will list the DPS rather than the entire taxonomic species or
subspecies.
NMFS and USFWS are currently reviewing public comment received on
the draft policy. We therefore consider the draft policy as non-binding
guidance in evaluating whether to list the Southeast Alaska DPS of
Pacific herring based on threats within a significant portion of the
range of the DPS. Lost historical range would not constitute a
significant portion of a species' range (and a species cannot be listed
solely on the basis of loss of historical range), but the causes and
consequences of loss of historical range on the current and future
viability of the species must be considered and are an important
component of determining the risk of extinction.
The ERA team did not find any portion of the range within the
Southeast Alaska DPS to warrant a different level of extinction risk.
Also, as discussed previously, we have no new information since the
Status Review of Lynn Canal Herring (Carls et al., 2008) to suggest
that any subset of Pacific herring in Southeast Alaska should be
considered a DPS. Therefore, the team concluded that the Southeast
Alaska DPS of Pacific herring is not at risk of extinction throughout a
significant portion of its range. We concur with this conclusion.
Conservation Efforts
When considering the listing of a species, section 4(b)(1)(A) of
the ESA requires consideration of efforts by any state, foreign nation,
or political subdivision of a state or foreign nation to protect the
species. Such efforts would include measures by Native American tribes
and organizations, local governments, and private organizations. Also,
Federal, tribal, state, and foreign recovery actions (16 U.S.C.
1533(f)), and Federal consultation requirements (16 U.S.C. 1536)
constitute conservation measures.
Conservation efforts may include habitat protection or measures
defining the limitations and extent of exploitation. The State of
Alaska is the managing body for herring fisheries in Alaska.
Consequently, conservation measures in place that regulate human
impacts on herring in Southeast Alaska are primarily in the form of
mandates to state agencies based on state legislation. Article 8
Section 4 of the Alaskan Constitution concerns the goal of sustainable
yield, whereby `` Fish . . . shall be utilized, developed and
maintained on the sustained yield principle, subject to preferences
among beneficial uses.'' State regulatory measures for herring
fisheries are designed to conserve herring stocks on a sustained yield
principle and have been described and evaluated above. State habitat
protection and conservation occurs through State project review and
subsequent recommendations to avoid, minimize, and mitigate impacts to
herring while in spawning grounds. The Alaska Department of
Environmental Conservation also implements Water Quality Standards
which may indirectly conserve herring habitat.
[[Page 18526]]
Conclusion
We have reviewed the status of the Southeast Alaska DPS of Pacific
herring, fully considering the best scientific and commercial data
available, including the status review report. We have reviewed the
threats to herring in Southeast Alaska, as well as other relevant
factors, and given consideration to conservation efforts.
Our review of the information pertaining to the five ESA section
4(a)(1) factors and ERA team evaluation of the current and projected
status of herring in Southeast Alaska does not support a conclusion
that there are threats acting on the species or its habitat that have
rendered herring in Southeast Alaska in danger of extinction, or likely
to become so in the foreseeable future, throughout all or a significant
portion of its range. Therefore, listing the Southeast Alaska DPS of
Pacific herring as threatened or endangered under the ESA is not
warranted at this time.
References Cited
A complete list of all references cited in this notice can be found
on our Web site at http://alaskafisheries.noaa.gov and is available
upon request (see ADDRESSES).
Authority
The authority for this action is the Endangered Species Act of
1973, as amended (16 U.S.C. 1531 et seq.).
Dated: March 27, 2014.
Samuel D. Rauch III,
Deputy Assistant Administrator for Regulatory Programs, National Marine
Fisheries Service.
[FR Doc. 2014-07368 Filed 4-1-14; 8:45 am]
BILLING CODE 3510-22-P