(OS36K-06) Simulated Herring Growth Reponses in the Northeastern Pacific to Historic Temperature and Zooplankton Conditions Generated by the 3-Dimensional NEMURO NPZ Model by NMF


									                                         (OS36K-06) Simulated Herring Growth Reponses in the Northeastern Pacific to Historic Temperature and
                                                     Zooplankton Conditions Generated by the 3-Dimensional NEMURO NPZ Model
                                                       Francisco E. Werner1, Kenneth A. Rose2, Bernard A. Megrey3, Maki Aita-Noguchi4 and Yasuhiro Yamanaka4,5
                                                     Univ. North Carolina, Chapel Hill, NC 27599, USA; 2Louisiana State Univ., Baton Rouge, LA 70803, USA; 3National Marine Fisheries Service, Seattle, WA 98115, USA;
                                                                4Frontier Research Center for Global Change, JAMSTEC, Yokohama, JAPAN; 5Environmental Earth Science, Hokkaido Univ., Sapporo, JAPAN

      BACKGROUND                                                                                                                                                               MATERIALS AND METHODS                                                                                                                        RESULTS
      The effects of climate on marine fish recruitment and populations have been the focus of study                                                                           Lower trophic level (NEMURO) model at basin scales: A 3-D implementation of NEMURO (Fig. 2) for the Northern Pacific was run for                All three locations, WCVI, PWS and BSea showed a shift in herring growth during the late 1970’s
      for decades. Environmental conditions can change gradually due to persistent trends in climate                                                                           the 1948 to 2002 time period (Fig. 1; and Aita et al., 2006). The simulated NPZ dynamics were used as input to a herring bioenergetics          (Fig. 4, top panels; and Fig. 5a). Herring growth decreased in WCVI and PWS, and increased in
      (e.g., gradual warming) or stepwise due to climate regime shifts. A climate regime can be                                                                                model (Fig. 3). See details in Rose et al. (2006a).                                                                                             BSea. Coincident with the shifts in herring growth were a warming of temperature (Fig. 4; second
      defined as a persistent state in climate, ocean, and biological systems, with a regime shift being                                                                                                                                                                                                                       panels) and decreases in predatory zooplankton (Fig. 4; bottom panels).
      an abrupt, non-random change from one state to another (see Figure 1). Interannual variation                                                                             Fish bioenergetic model: The model (Fig. 3) simulated the daily weight of an average herring individual based on input water
      can occur within a regime, but the climate conditions within regimes are relatively consistent and                                                                       temperature and zooplankton densities from the NEMURO simulation (Figs. 1 and 2). The bioenergetics model in this application was                               Figure 4.                                       WCVI                                                  PWS                                                                                             B. Sea
      persistent compared to the magnitude of change that occurs between regimes (King, 2005).                                                                                 decoupled from the bioenergetics and population dynamics models that were both dynamically coupled to the NEMURO model in Megrey                                                                   80
                                                                                                                                                                                                                                                                                                                                                                                               (a)                                          30      (a)                                            80                                            (a)

                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      g year-1
                                                                                                                                                                                                                                                                                                                                                                      g year-1

                                                                                                                                                                                                                                                                                                                                                                                                                                g year-1
      Quantifying how climate changes affect fish populations would allow us to attribute variation in                                                                         et al. (2006) and Rose et al. (2006b,c).                                                                                                                                                           40                                                        20

      population dynamics to nature versus fishing, and would also allow us to adjust harvest levels                                                                                                                                                                                                                                                                               0                                                         0

                                                                                                                                                                                                                                                                                                                                                                                 11.5                                                                                                               6
      dependent on favorable and unfavorable climatic conditions.                                                                                                                                                                                                                                                                                                                11.0
                                                                                                                                                                                                                                                                                                                                                                                               (b)                                                  (b)                                                                                         (b)


                                                                                                                                                                                                                                                                                                                                                                                 10.5                                                        7                                                      5


                                                                                                                                                                                                                                                                                                                                                                                  9.5                                                        6                                                      4

                                                                                                                                                                                                                                                                                                                                                                                                                                                             CHART or
                                                                                                                                                                                                                                                                                                                                                                                0.092                                                     0.088                                                  0.084

                                                                                                                                                                                                                                                                                                                                                                                               (c)                                                                                                                                              (c)
                                                                                                                                                                               Figure 2. NEMURO lower trophic model                                      Figure 3. Fish bioenergetics                                                                                           0.088

                                                                                                                                                                                                                                                         model                                                                                                                                                                            0.076


                                                                                                                                                                                                                                                                                                                                                                      uMN L-1
                                                                                                                                                                                                                                                                                                                                                                                               (d)                                                                                               0.090
                                                                                                                                                                                                                                                                                                                                                                                0.060                                                               (d)                                                                                                                                       (d)

                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      uMN L-1
                                                                                                                                                                                                                                                                                                                                                                                                                                uMN L-1
      H1: Geographic variation in fish growth. Differences in environmental conditions, and                                                                                                                                                                                                                                                                                     0.052                                                  0.060

                                                                                                                                                                                                                                                                                                                                                                                0.048                                                                                                            0.060
           resulting differences in lower trophic conditions, can account for the differences in herring                                                                                                                                                                                                                                                                                                                               0.055
                                                                                                                                                                                                                                                                                                                                                                                 0.18                                          (e)                  (e)                                                                                                                                      (e)
            growth rates among selected sites in the North Pacific ecosystem.                                                                                                                                                                                                                                                                                                    0.16
                                                                                                                                                                                                                                                                                                                                                                                                                                           0.14                                                   0.24

      H2: Understanding regime shifts. Synchronous changes in herring growth rates across                                                                                                                                                                                                                                                                                        0.14                                                      0.12

                                                                                                                                                                                                                                                                                                                                                                                        1950     1960   1970     1980   1990     2000             1950    1960   1970   1980   1990    2000              1950                                          1960      1970          1980      1990        2000
           locations may be explained by basin-wide decadal-scale changes in environmental                                                                                                                                                                                                                                                                                                                Year                                                    Year                                                                                                  Year
      H3: Global climate change effects on energy pathways and fish production. Climate change may                                                                                                                                                                                                                                                                                                                                                                                         Figure 5.
           result in energy being diverted from the pelagic pathway and shunted through the microbial                                                                                                                                                                                                                           BSea herring are larger than PWS and WCVI. The herring                                                                                                 (a)

                                                                                                                                                                                                                                                                                                                                at WCVI are the smallest, all supported by data (Fig. 5b;

           pathway, resulting in less food for pelagic fish and thus slower fish growth rates.


                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         Change in herring wet weight (g/yr)
                                                                                                                                                                                                                                                                                                                                Schweigert et al., 2002). The growth response was different                                                                                                                                                     70


      Our objectives are: (i) to understand the propagation of climate change effects up the marine                                                                                                                                                                                                                             by region and regime. While in 1976-1977 BSea herring                                                                                                                                                           50

                                                                                                                                                                               NEMURO (Kishi et al., 2006) was imbedded into the Ocean                                                                                          growth increased, the PWS and WCVI decreased. The

      food-web using a common marine food-web and fisheries bioenergetics modeling approach; and                                                                                                                                                                                                                                                                                                                                                                                                                                                30

      (ii) to quantify its effects on energy cycling and fish growth and production in distinct geographic                                                                     Component Model configured for the Northern Pacific Ocean                                                                                        opposite occurred in 1998-1999. Results were mixed in


      regions in the North Pacific and its marginal seas.                                                                                                                      by Aita et al. (2006). In the horizontal, the model’s spatial                                                                                    1988-1989.                                                                                                                                             (b)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                1945    1950     1955     1960    1965     1970

                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         1975   1980   1985   1990   1995   2000

                                                                                                                                                                               resolution is 1o latitude by 1o longitude. In the vertical there are
                                                                                                                                                                               54 layers with variable resolution: 5m in the upper 100m, 10m                                                                                    Examination of simulation results show these patterns were
      Figure 1.                                                                                                                                                                between 100m and 200m, and thicker below 200m. NEMURO                                                                                            driven mainly by food density in WCVI, a combination of food
                                                                                                                                                                               represented the NPZ dynamics with eleven state variables:                                                                                        density and water temperature in PWS, and by water
                                                    (2006; Ecological Modelling)                                                                                                                                                                             Maximum consumption rate CMax and R are computed as
                                                                                                                                                                               nitrate, ammonium, small phytoplankton PS, large                                                                                                 temperature in the BSea (Rose et al., 2006a).
                                                                                                                                                                                                                                                             functions of weight and temperature, while F and E, and S
                                                                                      Water Temperature (oC)

                                                                                                                                                                               phytoplankton PL, small zooplankton ZS, large zooplankton ZL,
                                                                                                                                                                               predatory zooplankton ZP, particulate organic nitrogen,                       are based on realized consumption. On the day of
                                                                BSea     PWS

                                                                                                                                                                               dissolved organic nitrogen, particulate organic silicate, and
                                                                                                                                                                               silicate. All state variables are in micro-moles nitrogen per liter.
                                                                                                                                                                                                                                                             spawning (March 15), the average weight of spawning
                                                                                                                                                                                                                                                             individuals is reduced by 25%.
                                                                               WCVI                             2
                                                                                                                                         Bering Sea
                                                                                                                                         Prince William Sound
                                                                                                                                         West Vancouver Island
                                                                                                                                         Oregon Coast
                                                                                                                0                                                                                                                                                                                                           Aita, M.N., Yamanaka, Y. and Kishi, M.J. (2006) Interdecadal variation of the lower trophic ecosystem in the Northern Pacific between 1948 and 2002,
                                                                                                                    1950   1960   1970           1980            1990   2000
                                                                                                                                                                                                                                                                                                                                        in a 3-D implementation of the NEMURO model. Ecological Modelling, accepted.
                                                                                                                                                                               Linking NEMURO with the fish bioenergetics: We used the output of the NEMURO-3D simulation at three locations (Figure 1): off the            King, J.R., editor (2005) Report of the Study Group on the Fisheries and Ecosystem Responses to Recent Regime Shifts. PICES Scientific Report
                                                                                                                                                                               West Coast of Vancouver Island (WCVI), Prince William Sounds (PWS), and in the Bering Sea (BSea) as input to the bioenergetics model                     Number 28, North Pacific Marine Science Organization (PICES), Institute of Ocean Sciences, Sidney, BC, Canada.
                                                                                                                      (Above) Time series of                                                                                                                                                                                Kishi, M.J. and 26 co-authors (2006) NEMURO - Introduction to a lower trophic level model for the N. Pacific marine ecosystem model. Ecological
                                                                                                                                                                               and simulated the daily growth of herring for 1948 to 2000.                                                                                              Modelling, accepted.
                                                                                                                      monthly temperatures at
                                                                                                                                                                                                                                                                                                                            Megrey B.A., Rose, K.A., Klumb, R., Hay, D., Werner, F.E. and Smith, L. (2006). A bioenergetics population dynamics model of Pacific herring
                                                                                                                      selected sites off the                                                                                                                                                                                            (Clupea pallasii) coupled to NEMURO: dynamics, description, validation and sensitivity analysis. Ecological Modelling, accepted.
                                                                                                                      North American west                                      Detection of Regime Shifts: We applied the sequential t-test analysis to detect regime shifts, as in the STARS algorithm of Rodionov and     Rodionov, S. and Overland, J.E. (2005) Application of a sequential regime shift detection method to the Bering Sea. ICES J. mar. Sci. 62, 328-332.
                                                                                                                      coast. Together with the                                 Overland (2005) to the simulated temperatures, zooplankton, and herring growth rate (annual change in weight betweens ages 3 and 4) to       Rose, K.A., F.E. Werner, B.A. Megrey, Aita-Noguchi, M., Yamanaka, Y., Hay, D. and Schweigert, J. (2006a) Simulated Herring Growth Reponses in
                                                                                                                                                                               identify statistical shifts in their average values. We compared these shifts within and among locations to determine if herring responses               the Northeastern Pacific to Historic Temperature and Zooplankton Conditions Generated by the 3-Dimensional NEMURO Nutrient-
                                                                                                                      zooplankton time series                                                                                                                                                                                           Phytoplankton-Zooplankton Model, Ecological Modelling, accepted.
                                                                                                                      (left), these values                                     were consistent across populations.                                                                                                          Rose, K.A., Megrey, B.A,. Hay, D., Werner, F. and Schweigert, J. (2006b) Climate regime effects on Pacific herring growth using coupled nutrient-
                                                                                                                      provided the input to                                                                                                                                                                                             phytoplankton-zooplankton and bioenergetics models. Trans. Am. Fish. Soc., accepted.
                                                                                                                      compute the growth of                                                                                                                                                                                 Rose, K.A., Megrey, B.A., Werner F. and Ware, D.M. (2006c) Calibration of the NEMURO nutrient-phytoplankton-zooplankton food web model to a
                                                                                                                                                                                                                                                                                                                                        coastal ecosystem: evaluation of an automated calibration approach. Ecological Modelling, accepted.
                                                                                                                      individual herring.                                          Authors’ e-mails: cisco@unc.edu; karose@lsu.edu; bern.megrey@noaa.gov; macky@jamstec.go.jp; galapen@ees.hokudai.ac.jp                    Schweigert, J., Funk, F., Oda, K. and Moore, T. (2002) Herring size-at-age variation in the North Pacific. PICES Scientific Report 20, pp 47-57.

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