Development of Multi-Dimensional Ecosystem Indicators

1. Development of Multi-Dimensional Ecosystem Indicators Bill Overholtz, Jason Link, et al. NOAA NMFS NEFSC Woods Hole

2. SRTM30_PLUS: SRTM30, COASTAL & RIDGE MULTIBEAM, ESTIMATED TOPOGRAPHY Joseph J. Becker & David T. Sandwell 30 second grid resolution = 0.9 km This map = 1.25km/pixel

3. Satellite Sea Surface Temperature Courtesy Jay O’Reilly

4. Indicators- Overview • Indicators/metrics are an active area of applied and theoretical marine research • To do EBFM/EAF/EM, indicators by necessity must represent a multidisciplinary perspective • Translating indicators into Decision Criteria for EM is THE next big challenge

5. Woods Hole Temperature - NAO Courtesy D. Mountain Both series smoothed

6. Pillars of Any Management System 1. Goal Setting (Priorities & Allocation of Biomass) 2. Assessing Ecosystem Status(MV Metrics) Indicators are used at all steps in the process 3. Achieving Ecosystem Goals (Management Tools)

7. Indicators- Which ones and how many? • At least initially, Status Indicators should be as inclusive as possible (in terms of germane processes) • Indicators must span full range of appropriate biological, physio-chemical & socio-economic factors • Yet, the global experience is that a long “laundry list” of indicators is not immediately helpful for EM

8. Vetting Indicators • Desirable Properties of Indicators: • Directional • Sensitive to change • Range spans natural variability • Precision and variance estimable & reasonable • Unambiguous • Not duplicative nor repititious • Expressive/representative of key processes

9. Usual Categories/Classes of EBFM Indicators • Size • Production • Diversity • “Canary” species • Energy Flow - Trophodynamics • Habitat • Physio-chemical Regime • Management Performance - Response

10. Traffic light-consumer report approaches Based upon empirical distributions Metric 1 Metric 2 Metric 3 Etc.

12. Using the Traffic Light Approach No one buys a toaster or automobile that has consistent and multiple orange or red ratings Similarly, fisheries managers and stakeholders would like a greener overall system status relative to the history of the system In redder conditions, caution is heightened One could then choose situations to make the overall status of the system greener (Fuzzy logic models) Assumes mechanisms and specific processes to obtain green conditions are known and manipulatible Although qualitative, feasible for most agencies to at least use in assessing system-level status

13. Reference Surfaces & AMOEBAS • Surface plots allow the simultaneous evaluation of 3 to 4 dimensions. Often used to show concurrent minima or maxima. • Polar plots (compass plots) allow the simultaneous evaluation of multiple indicators. Often used to examine Biological LRP concurrently. • Both can be either model or empirically based. • Pro- evaluation of multiple indicators simultaneously • Con- limited to a select set (subset) of indicators, not necessarily integrative.

14. Reference Surfaces

15. AMOEBAS

16. Summary: Surfaces & AMOEBAS • Both can be used to set regions of desirability (e.g. aiming for local maxima, avoiding a global minima, bounded within a universal circumference, etc.) in a reference point (surface) sense. • Are particularly useful in evaluating a family of related indicators (e.g. Biological Limit Reference Points).

17. Multivariate Analyses • PCA, MDS, etc. can help to reduce dimensionality • Can help to detect major systemic patterns • Can provide indicator weighting to determine the major processes acting upon the overall system • Also useful in a culling/vetting exercise • Canonical Analyses- CanCorr, CCA, RA, DA etc.- can help to elucidate causality between multivariate pressure and response indicators.

18. 0.5 GB Temp 0.4 MAB-s Temp MAB-n Temp Groundfish Biomass GOM Temp 0.3 Total Biomass 0.2 Other Groundfish Evenness Pelagic Biomass 0.1 Richness PC 2 (16.7%) Mean Wt Profit per Vessel 0 Skate Landings -0.5 -0.3 -0.1 0.1 0.3 0.5 -0.1 NAO Elasmobranch Biomass -0.2 Groundfish Landings: 2 Classes Dogfish Landings -0.3 Total Number Vessels -0.4 PC 1 (30.8%) • Axis 1- groundfish (biomass, landings), profit, evenness & fish size vs. elasmobranchs & pelagics • Axis 2- temperature & groundfish vs. effort (landings, # vessels) • Various permutations explain 45-60% of total variance with similar results

19. 2 1995 1999 1.5 1973 1977 1 0.5 1968 1985 PC 2 0 -2 -1.5 -1 -0.5 0 0.5 1 1.5 2 -0.5 1980 1989 -1 -1.5 -2 PC 1 • Multivariate trajectory generally counter-clockwise • Scores on first axis generally increasing across time • Scores on second axis lower during 1980s • Can we get from current position (upper right quadrat) to 1960s or early 1970s conditions (upper left quadrat)?

20. Canonical Correlation- Axes 1; R2=94% Canonical Correlation- Axes 2; R2=71% 3 3 2 2 1 1 Response Response 0 0 -3 -2 -1 0 1 2 3 -3 -2 -1 0 1 2 3 -1 -1 -2 -2 -3 -3 Explanatory Explanatory • First 2 canonical axes explain 81% of the total variance among response variables • Linear relationships between explanatory and response canonical axes are significant and strong

21. Correlation of Response Metrics with Canonical Axes 1 Elasmobranch Biomass 0.5 Other Groundfish Biomass Total Biomass Explanatory Axis 2 0 -1 -0.5 0 0.5 1 Mean Wt Richness Groundfish Biomass -0.5 Evenness Pelagic Biomass -1 Explanatory Axis 1 • Assuming causality, we interpret the canonical correlation as: • 1) hi groundfish landings, hi elasmobranch landings, hi # vessels, and hi MAB temperatures produce low groundfish biomass and hi pelagic biomass; • 2) hi levels of effort and sequential fishing produce smaller-sized fish, low biomass of other groundfish (i.e. demersals), and lower species evenness

22. Summary of MV Analysis In example, PCA explains 50% of total variance among the ecosystem metrics MV trajectory confirms and integrates metrics of multiple processes Canonical correlation useful: MV relationships established Relative importance of different processes MV reference points/directions possible, although empirically based Can we get from one quadrat to another?

23. Indicators & Decision Criteria • Most indicators are not yet usable as reference points • Empirical use of indicators as a function (or partial function) of a stressor (e.g. F) can help establish specified thresholds or LRPs • Development of empirically based indicator thresholds needs further work, but can be used NOW to establish some intermediate decision criteria • The role of MV Reference Directions, Surfaces, etc. merits further examination and application

24. Decision Criteria • Single Species Fisheries- • Model & empirical-based ref points • Model-based control rules RP RP

25. Decision Criteria • Toxicity & Ecological Risk Assessment- • Model & empirical-based ref points • Model-based control rules • Are these arbitrary? • What’s special about a set fraction of survivorship or 50% of K or so forth CR RP RP

26. Decision Criteria • Single Species- • Model & empirical-based ref point • Model-based control rules • Action to be taken shows direction and magnitude CR RP RP • Ecosystem- • Empirical-based ref points & directions • Arbitrary/empirical control rules • Action to be taken may only show direction CR(p) CR(q) RQ/RP

27. Using MV Indicator Derived Reference Directions, Surfaces, Quadrats, AMOEBAS, etc. What quadrat are we in (e.g., from PCA, or surface, or pole, etc.)? What quadrat do we wish to be in? Irrespective of mechanism, what factors produce the conditions in the desired quadrat (e.g., from CanCorr)? Which of these can we control? Can we then limit effort, landings, etc. for particular aggregate groupings to obtain the desired response? Or do we simply need to wait for a change in environmental conditions? Assumes a reversible trajectory and causality among canonical axes

28. Empirically Derived Indicator-Based Reference Points & Thresholds • How we established the Thresholds and LRPs • Determinants of change • Empirical observations • Linked to major events in US NW Atlantic Ecosystem • Inflection points or regions of change • Supported by strong literature and theoretical basis • Link (2005) “Translating ecosystem indicators into decision criteria”

29. Decision Criteria: Slope of Size Spectrum <)10 OK N/A Threshold )10+ Limit

30. Decision Criteria: Aggregate Biomass BTL4+ < 25% BTL3 OK > 25% BTL3 Threshold > 50% BTL3 Limit

31. Decision Criteria: Trophodynamics LE < 5% PP OK > 5% PP Threshold > 10% PP Limit

32. Summary Assessing the status of an ecosystem is not trivial, but is feasible Need multiple metrics to assess ecosystem status and develop system reference points MV methods exist to establish and synthesize relationships & relative importance among numerous processes in marine ecosystems We now know the status of many marine ecosystem- trends, magnitudes, and relationships- in a manner we have never known before

33. What do we need? • Further Identification and Vetting of key ecosystem Indicators • Establish Indicators as a function of F (or other stressors) relative to other potential perturbations • Commitment to data sources • Commitment to modeling resources and development • Novel ways to package, combine, visualize & communicate the multi-attribute, multivariate information • More formalized decision analysis, MSE, DSS, and similar approaches to better use translated Indicators