Petition to List Lynn Canal Pacific Herring under the Endangered ...

net air-sea CO2 exchange, fishery yields, and dominant basin-scale biological
regimes.
(Behrenfeld 2006: 754)(internal citations omitted). Oceanic food-web changes have
already been documented in the North Pacific. These changes are implicated in the
severe decline of many species of fish and marine mammals.
The “ocean climate hypothesis” is an alternative explanation for the rapid changes
that were observed to cross all trophic levels of the North Pacific (National
Research Council 1996, Trites et al. in press). This bottom-up hypothesis is
supported by a large and growing body of evidence (e.g., Ware and Thomson
2005, Trites et al. in press). For the past 100 yr, 10–30-yr periods of stable
physical conditions have been punctuated by rapid shifts to alternative stable
physical oceanographic conditions (Ebbesmeyer et al. 1991, Graham 1994,
Beamish et al. 2000, McKinnell et al. 2001, King 2005). These sudden and welldocumented
“regime shifts” significantly affect sea temperatures, currents, and
ice coverage—and correspond in space and time with ecosystem changes noted in
Alaska and in British Columbia (Hare and Mantua 2000, Benson and Trites 2002,
King 2005).
(Trites et al. 2006). An ecological risk assessment performed on Cherry Point Herring by
Landis et al. (2004) concluded that ocean conditions significantly affect Pacific Herring.
An analysis of the Cherry Point Pacific herring age structure and population
dynamics indicates that the loss of reproductive potential of the older age class
fish was the population characteristic that led to the decline of the run.
Exploitation, habitat alteration and climate change are the risk factors that
contribute to the decline of the Cherry Point Pacific herring. The retrospective
assessment identified the cyclic nature of climate change, as expressed by the
warmer sea surface temperatures associated with a warm Pacific Decadal
Oscillation (PDO), as the primary factor altering the dynamics of the Pacific
herring.
(Landis et al. 2004).
Reduced phytoplankton productivity in the Lynn Canal area would have dire
consequences for Pacific Herring. In particular, juvenile herring during the first winter
are susceptible to environmental changes with little room for error to ensure survival.
Marine perturbations that decrease food availability would inevitably cause greater winter
mortality of juvenile herring, thereby depressing the future spawning generations.
Cooney et al. (2001) found that juvenile herring were subject to substantial starvation
losses during a winter period of plankton diminishment.
[W]e determined that if a juvenile herring arrives at the beginning of
oceanographic winter in late November or early December with an energy content
of 5.0 kJ/g and burns energy without supplemental feeding at 23 J/g day–1, it will
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