UNITED STATES DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Marine Fisheries ServiceP.O. Box 21668
Juneau, Alaska 99802-1668

Summary of Peer Reviewer Comments and Response for the Status Review ofSoutheast Alaska Herring (Clupea pallasi)

Between November of 2012 and March of 2013, the draft Status Review of Southeast Alaska
Herring (SR) was evaluated through a formal peer review process. During this review, edits andcomments were collected from three reviewers, including two research fisheries biologists withparticular expertise in herring from the National Marine Fisheries Service Auke Bay Laboratory,in Juneau, AK as well as a herring biologist and Section Head with the Department of Fisheries
and Oceans' (DFO) Pacific Biological Station in Nanaimo, BC. All of the comments of thesereviewers as well as the response from NMFS PRD staff are included in the following tables. Insummary, of the 48 comments made by the three reviewers, 17 included suggestions for
additional information or confirmation of existing information, 13 included recommendations for
a format change such as shortening a section, 11 included suggestions or questions regarding
data analysis/presentation such as the efficacy of trend lines, and the remaining 7 included
comments either questioning information in the document or requesting further evidence insupport of information. None of the comments on any particular section were shared by thereviewers. NMFS PRD staff responded to all of the comments and added, modified, deleted text
from the document or noted accordingly.

K. Savage, Jan. 15, 2014

ALASKA REGION - http://alaskafisheries.noaa.gov

Topic/Threat

Section

Reviewer CommentResponse

Relative to tropical and some temperate species Pacific herring are slow growing and latematuring fish.

ModifiedThe sections relating to habitat covered much of the available literature but I didn’t get asense of whether this was a threat that should be given much weight. It appears that with afew exceptions (Auke Bay) most of the spawning areas in southeast Alaska remain relatively
unaffected by anthropogenic impacts and so habitat alteration poses little risk to herringproduction and can’t really be considered as a threat to the DPS as a whole. If thisimpression is incorrect I think there needs to be more clarification in the document.

Modified.

Life History

Tee Harbor June Pelican late June

Modified.

Pollution

Cruise ship's discharge

Addressed later indocument

Marine traffic and noise

Herring also respond to light, night time acoustic surveys in PWS run with lights out to avoid
altering herring behavior

Noted.

This really is an amazing case study. However, as this is a status review of all herring acrossSE, a more comprehensive case study would include the story of Sitka sound here. Above
I’ve highlighted two sections that (1) mention the recent increase in herring biomass, and(2) discuss habitat modification in Sitka sound. Putting this case study into perspective bycomparing it to a stock that has opposite trends in abundance may be enlightening tohighlight the potential differences that could be contributing to the decline in Auke Bay andthe increase in Sitka Sound.

Added.

Maybe convert this to tons for more direct comparison with catch statistics (e.g., 2,502 tons,or 2,270 tonnes)

Modified.

I’m guessing that you don’t include trend lines when the trend isn’t significant. I would
suggest including them, because it does give one a feel for the trend, and just note for eachplot whether or not they are significant.

Deleted trend lines.

Consider including a trend line (like I’ve done below) when Sitka is not included. Also
consider a quantifier to “differs substantially”. For example, maybe include “the positive
slope differs nearly by 4”.

Deleted trend lines.

Consider changing the color and line type of the trend lines to match the data they aretrending, it will help differentiate them. Like I’ve done here…

Deleted trend lines.

Parameters ofVulnerability

HabitatModificationAuke Bay

Trends in AbundanceOverutilization

Recruitment2

Topic/Threat

Overutilization

DiseaseSection

Reviewer Comment

Response

Age-at-maturity

This maturity ‘data’ are results from the ASA models for these stocks. These same maturity
curves are available for any ASA assessed stock (including Sitka). Similar to the preceding
figures, you could also plot just Sitka, then the average of the ‘other’ stocks or something.

Noted.

Mean length and weight

One question I have is whether the data used in these figures are with the updated ages or
the older, uncorrected ages….

Noted.

Condition Factor

The reason that these slopes are so small is because K is so small, which does notnecessarily mean that these differences are practically negligible. If one were to multiply Kby 100,000 (like is what appears to have been done in the following figure) these slopes
would become much more different than zero…

RemovedThis plot doesn’t seem to match the slope coefficients in the following table. Are these slope
coeficients reported in the table for Hoonah only from 2002-2008? To be consistent withthe other stocks, they should be for the entire time series, which would put them on thesame scale.

RemovedMaybe consider deleting this, doesn’t really seem necessary as it kind of goes without
saying...

RemovedThe scale of these values doesn’t seem correct… For example, in Figure 59 above, average
length across years for Sitka herring was around, say, 225 cm. Average weight across years
3
in Figure 60 was around 145 g. K being W/L would then be ~1.27E-5. It should be noted-5
that the y-axis is on the scale of 10 , or, that K is multiplied by 100,000.

Removed

The way this reads currently is that the effects of disease has been debated, which issomewhat misleading. The debate is mostly over the magnitude and prevalence of specificpathogens. IMHO I would edit this part of this sentence to something like: “… although themagnitude and prevalence of specific pathogens has been debated…”

Modified

Also ADFG test fisheries where a lot of fish are captured in a purse seine, a few sampledwith the rest being released.

NotedWe have speculated that the heavy predation by whales during the winter could increasestress and thus disease in PWS.

Modified

The issue of disease as a threat to herring remains unresolved. Certainly the few studies andattempts to conduct baseline surveys have shown various diseases to be endemic to herring
but whether they cause ongoing low to moderate levels of mortality is unclear. It is alsodifficult to generalize more broadly from the extensive studies in Prince William Sound
where herring have continued to experience some level of stress from the oil spill.

Noted3Topic/ThreatPredation

Section

Reviewer Comment

ResponseShorten

Shortened

Unevenly includes marine mammals and piscivorous fish (vs. birds and marine mammals).
Requires discussion on uncertainty of estimates of predation.

Depends upon
available
informationGeneral predation

A problem for herring is that they aggregate in dense schools during spawning andoverwintering, thus even at low population levels the dense schools may still be attractive
to predators.

Added

Cetaceans

Gray whales eat herring and herring eggs in Sitka and PWS. I think sea otters do too

Cetaceans

I believe this is mostly summer work when salmon are abundant. Residents take ground fishfrom longlines I don' think it is known what they are feeding on in winter.

Humpbacks

In inside waters, Maybe T. Pacifica outside.

Added in insidewaters

Humpbacks

Humpbacks also compete with herring for zooplankton.

Added

HumpbacksThis is important, some whales seem to specialize in herring or have prey preferences
regardless of what alternate prey is available.

Addressed later indocument

Stellers

I think some recent tagging studies may contradict this. During the winter sea lions moved
all over SEAK rather than staying at one spot.

DeletedStellers

Check with ADF&G, tagged animals seemed to miss the big herring schools in PWS

DeletedStellers

What about harbor seals? Fur seals use to feed on spawning herring in Sitka

Harbor seal
populations arefluctuating
throughout
Southeast Alaska
and have been lesswell characterized
as a herring
predator comparedto Steller sea lions.

Inverts, Fish

These fish also compete with herring. Also I saw adult herring feeding on larval/juvenile
herring off Eagle Beach.

Noted

Inverts, Fish

The size of halibut has also been reduced. There aren't many big ones left. There is ahypothesis that the lack of big predators has created a mesopredator release with species
like ATF and cod.

Noted

Predation

ATFs eat herring and I think their biomass is going through the roof

Noted4Skip - nodocumented info
provided
Modified according
to Ford and Ellis
2006

Topic/Threat

Section

Reviewer Comment

Response

Herring fisheriesThis ‘however’ seems out of place. Further, the first sentence doesn’t seem to be needed
under the ‘Herring fisheries’ section. You may consider deleting the first sentence, andleading with: “Regulatory mechanisms with the greatest current impact on Southeast Alaska
Pacific herring stocks are ADF&G management plans and harvest strategies for exploitedstocks.”

Modified

Just added in other sources of data used in the ASA model. Note that in PWS the mile-daysof milt is used as an additional index.

Modified

The way this currently reads, variance estimates were included for all data sources for the
first time, which isn’t correct. Variance estimates were always used in the ASA model(otherwise you’re using VPA or other deterministic methods and treating the data as‘known’). In 2008, annual variance estimates were provided (rather than constant varianceacross years) for the spawn deposition data, which incorporated uncertainty in the data, notthe modeling process. Further, the spawn deposition is data that was weighted, and is not aparameter.

Modified

This is not entirely correct. The PDO has been used to define time-periods for parameters(which is discussed below). For example, parameters for natural mortality and maturity are
estimated within time-blocks of the PDO phases. This is done for all the SE stocks (that areassessed with ASA models) as well as in PWS for maturity. Consider changing this sentence
to “The phases of the Pacific Decadal Oscillation index has also been used to define time
periods for parameters estimated”.

Modified

Stock assessment

Check this. Usually parameters aren’t weighted (except through a penalty function, forexample, to dampen recruitment estimates), data is weighted…

Corrected.

Stock identification

So is this statement inferring that herring from other stocks are moving to Sitka? To behonest, it’s something that I’ve postulated to myself several times before, but no analysis
I’ve done indicates that as a possibility (i.e., the decile in other stocks comes nowhere close
to the increase in the Sitka stock). IMHO, this seems like a pretty big statement to makewithout substantiating evidence. This whole section does provide interesting researchleading to this possibility. But, consider mentioning that this statement isn’t corroborated
by any analysis done to date.

Modified

Assessment of abundance
The Inadequacy ofExisting
Regulatory
Mechanisms

5Topic/ThreatSection

Reviewer Comment

Response

Data collection methods

These statements are out of context here. The Thomas and Thorne (2003) study was for
PWS herring. Further, Hulson et al. (2008) showed that the same results can be found with
the ASA model, depending on the weighting of the datasets. The main issue in PWS in thelate 1980s and early 1990s was that there was a conflict between the mile-days of milt
(which was the index that Thomas and Thorne (2003) used, not ‘miles of beach spawning’,
which they mis-define in that study), and the spawn deposition datasets. Depending on
which dataset one weights higher (either the mile-days or spawn deposition) the decline
either started in 1988 or 1992. In other words, if one were ignore all the other sources of
information for PWS herring other than the mile-days of milt, the same results occur as
Thomas and Thorne (2003). Further, ADF&G pre-fishery monitoring on the fishing grounds
did not detect the collapse until 1993, which follows the results of the spawn deposition
survey. If these statements are to remain it should be noted that: (1) they apply to PWS, and(2) Hulson et al. (2008) also highlights a number of inadequacies of the Thomas and Thorne(2003) study, including the assertion that the ASA model consistently overestimates.

Corrected.

I read this above also. IMHO it’s not so much that we can’t express them in mathematicalform, it’s that we don’t have the observations that support more complex mathematicalconvention.

Noted

In the ADF&G herring models, parameters aren’t weighted, data is.

Corrected.

Not sure exactly what is meant here. There are only a limited number of models that
implement M. For example, surplus production models don’t use M, but use carrying
capacity, productivity, and a shape parameter. VPA and ASA do, but results from either
structure of model would be similar depending on the choice of M. Further, the remainderof this paragraph deals with the value and form chosen for M. Thus, I would suggest
omitting ‘the model used’ from this sentence and state that it has to do with the value andform chosen for M.

Corrected.

The sections on overutilization of herring fisheries, stock assessment and natural mortality
seemed to be too long and somewhat unfocused. It seemed like there was a lot of material
available so it was all included but I didn’t get a sense of the main points and conclusion thatwere to be drawn from this section. Perhaps that will be clarified in the Extinction RiskAnalysis.

Corrected.

The Inadequacy ofExisting
Regulatory
Mechanisms

Modeling

6Topic/Threat

Section

Other

Anthropogenic climatechange

Reviewer Comment

Response

Shorten

Modified

The sections on climate change, risk due to acidification and regime shifts seem too
speculative to be useful for assessing extinction risk. I question whether climate change
should really be considered as a threat since it isn’t something that can be readily mitigated.
I think the pertinent question is whether herring will be able to adapt to changing climate
rapidly enough to persist in this region. Similarly, although regime shifts have occurred in
the past with significant effects on herring production in British Columbia and presumably
Alaska, it is unclear how or if they will persist over and above the effects from global
warming to the extent that they will continue as drivers of productivity over extended
periods of time.

Noted

I believe there is some OA work on the pterapod Limacena helicina really important toherring and salmon in our waters

Noted7