Example #2: Northwest Pacific Zooplankton San WS on Forecasting Ecosystem Indicators with Process-based Models September 7-10, 2012, Friday Harbor, WA Section 1: Examples of simple diagnostic models of ecosystem response to climate forcing Example #2: Northwest Pacific Zooplankton And next, I will show the biogeographical change in copepods community. It was reported that intensification of the AL also affected dynamics of Oyashio and Kuroshio. Oyashio southern limit shifted southward, while Kuroshio flow increased after the 1980s. Sanae Chiba, RIGC, JAMSTEC Andrew Davis, Georgia Tech

Process 1 Process 2 Aleutian Low dynamics Winter Wind Stress Wind-driven, Mixed Layer bottom-up process Process 2 Advective transport by oceanic currents Aleutian Low dynamics Winter Wind Stress Winter Vertical Mixing Light & Nutrients availability Subarctic circulation Oceanic Currents Dynamics *Lagged response in some cases Advection Advection Climatic forcing phytoplankton Physical environment Production Phenology Community structure Chemical environment Untill now, I have shown the scenario related to wintertime wind stress. Zooplankton Biological process Production Phenology Community structure Distribution shift Conceptual Model for Climate – Ecosystem link in the subarctic NP

Low Frequency Variation in Zooplankton Biogeography (May-Sept, Area mean) (Yatsu et al. 2012, Yeosu Symposium) < 5°C at 100 m: Oyashio > 5°C at 100 m: Transition bottom depth > 500 m Data: Odate Collection 1960-1999 37 Species Number of samples analyzed Oyashio: 961 Transition zone: 969

Distribution of Cold Water Copepod Community before & after RS in North & South Domains 1960-1975 1981-1999 (20.8%) shift (Rodionov 2006) (Chiba et al 2009, GCB)

Distribution of Warm Water Copepod Community before & after RS in North & South Domains 1960-1975 1981-1999 (15.5%) shift (Rodionov 2006) (Chiba et al 2009, GCB)

Change in Copepod Community before & after RS in North & South Domains Abundance Diversity Biogeographical distribution of the copepods community in the Oyashio and the Transition zone before 1976 and after 1981: total abundance (Log ind. 1000 m-3) a), species diversity (H’) b) and the average community size (mm) c). (Chiba et al 2009, GCB)

Change in Oyashio & Kuroshio after RS for 1976 ~ 1981 March-May avg. Oyashio shifted to South Year avg. Kuroshio Transport increased (137°E) Japan Meteorological Agency http://www.data.kishou.go.jp/shindan/b_2/b_2.html The timing of shift detected by method by Rodionov (2006)

Change in Copepod Community before & after RS in North & South Domains Background Change in Copepod Community before & after RS in North & South Domains Both Northern and Southern Copepods concentrated in the narrow area in the Transition Region This region is nursery ground of many commercially important fish species. So results our study implies zooplankton community shift might caused not only The temporal but also spatial match-mismatch with the higher trophic levels. H1: In PDO positive (KO strong) yrs, more Northern (Southern) zooplankton area transported to South (North)

Passive Tracer Experiment by OFES global ocean model to assess the effect of low-frequency transport on variations in zooplankton community in the KOE OFES 3 days Output (1/10)° for 1950-2000 Climatology forcing: NCEP/NCAR reanalysis data Release: March, Count: September We used this model-derived current data to drive a Lagrangian transport algorithm we developed similar to one proposed by Binning and Celia (2002). This algorithm simulates both the advection and diffusion of passive tracers- particles with negligible mass and neutral buoyancy. In this case, these particles represented the zooplankton measured in the Odate collection. We released particles from both areas in March, coinciding with zooplankton spawning, then counted the number of particles from both regions ending up in the sampling area in September

Distribution of Cold Water Copepod Community before & after RS in North & South Domains x RS x 1960-1975 1981-1999

Distribution of Warm Water Copepod Community before & after RS in North & South Domains x RS x 1960-1975 1981-1999

Model vs. Observation: Cold Water Copepods Transport to South: Zoo-N2NB N.S. Zoo-N2NB N.S. (May-September)

Model vs. Observation: Warm Water Copepods Transport to North: Zoo-S2SB R = 0.580 Zoo-S2SB R =0.443 May-September

Change in Copepod Community before & after RS in North & South Domains Background Change in Copepod Community before & after RS in North & South Domains Or.. model setting should be revised… This region is nursery ground of many commercially important fish species. So results our study implies zooplankton community shift might caused not only The temporal but also spatial match-mismatch with the higher trophic levels.

(Yatsu et al. 2012, Yeosu Symposium) Time series of biomass and catch of commercially important fish species in KOE LTL-HTL Link QUESTION: Did biogeographical shift of copepods cause Spatial Match-Mismatch with HTL? Need to consider “Seasonality” in copepods transport and lifecycle for migrating fish. (Yatsu et al. 2012, Yeosu Symposium) 16

Seasonality in Zooplankton Transport August – September condition is most important for northward transport R

Available Zooplankton Dataset / LTL indices in subarctic western NP Odate Collection 1960s -1999, monthly-area mean (large missing data) Warm-Cold species ratio (based on references) Size index (larger or smaller than 2mm,Community mean size) Developmental Stage of Major spp (e.g. Neocalanus spp.) N & C SI of Major spp (e.g. Neocalanus spp.) Species diversity (SID, ‘H) PC Score North Pacific CPR 2000 - 2009, 3 transects/yr Warm-Cold species ratio (based on references) Size index (larger or smaller than 2mm,Community mean size) Developmental Stage of Major spp (e.g. Neocalanus spp.) N & C SI of Major spp (e.g. Neocalanus spp.) Species diversity (SID, ‘H) (to be ready) PC Score (to be ready) Plus phytoplankton index: diatom-dinoflagellate rasio, etc.)

CPR Observation Data http://www.pices.int/projects/tcprsotnp/default.aspx/#data Cool-warm spp distribution and variation of subarctic boundary Batten, S.D. and Freeland, H.J. (2007). Fisheries Oceanography, 16, 536-646. PDO & Latitudinal Shift of Neocalanus spp. North Warm CPR is C….. NP CPR survey has been conducting…

Thank you 