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Ecosystem & Multispecies Modeling at the NEFSC. NEMoW Aug. 30, 2007. Gradient of Possibilities. Stock/Single Species. Multi-species. Aggregate Biomass. Ecosystem. Messy Picture Here. Gadids. Pelagics. Flatfish. SS models, forget ecosystem issues. Whole System Models, forget pop dy.
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Ecosystem & Multispecies Modeling at the NEFSC NEMoW Aug. 30, 2007
Gradient of Possibilities Stock/Single Species Multi-species Aggregate Biomass Ecosystem Messy Picture Here Gadids Pelagics Flatfish SS models, forget ecosystem issues Whole System Models, forget pop dy Multi-species assessments Aggregate Biomass Models SS assessments with explicit M2 or habitat or climate considerations Multiple SS assessments in “harmony”
SS Add-ons • Increasing #s of extant cases incorporated into assessments • Still slow “uptake kinetics” in overall Mgt process • Yields generally lower if predation is considered as a component of total mortality • Remains critical for most “forage” species • Starting to include environmental cues
e.g., Larval Fish Trophodynamic Model Lough et al. 2005. Fish. Oceanogr. 14:4, 241-262
e.g., Linked Climate-Population Models Climate (IPCC Air Temperature to Estuarine Temperature) Fisheries (Environmentally-explicit population model: R as a function of T) F=0.8 550 ppm Management (Link Forecasted SSB to Management Benchmarks) Based on mechanistic hypothesis developed in Hare and Able (2007) Fish Oceanogr 16: 31-45.
Multispecies Models • MSVPA, MSProd, AggProd etc. • Formal review process for 1 region, 2nd planned • Effects of predation the main emphasis
e.g., MSVPA • >15 spp • Age/size structured • Focuses on M2 of main “forage” stocks Temporal Variation in Fishing vs. Predation Mortality, Atlantic Herring ages 0-2
ICNAF & Two-Tiers • Historical example of Two-tier quotas • Precedence in tropical systems • Rationale is to account for: • Overall system production • Biological and technical interactions • An additional level of “precaution” • MS & Aggregate Production models • Currently exploring “guild” or functional group, or aggregate group, or etc. as potential Mgt “stocks”
250 Guild Biomass- Base Scenario 200 150 100 50 0 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 Time Benthivores Planktivores Shrimp-Amphipods Shrimp-Fish Piscivores Base Scenario
250 Guild Biomass- Scenario 3 200 150 100 50 0 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 Time Benthivores Planktivores Shrimp-Amphipods Shrimp-Fish Piscivores Scenario 3: Over-Fish Pelagics
EMAX • Energy Budgets/ Network Analyses • Emerging as a tool for: • Heurism • Strategic Mgt • Tradeoff Evaluation • MSE • Considered as part of formal trade-off analysis • Dynamic models next
ECOGOMAGG • A home grown dynamic model • Builds off of EMAX (energy budget) outputs
ATLANTIS NEUS • Full blown ecosystem simulations • Still in validation & development stage • An important Mgt tool • Systemic Perspective • Virtual “perturbations” • MSE
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 Ecological Indicators • Outputs both from empirical and modeling studies • Evaluate a broad suite of ecosystem properties • Vetting ongoing, MV Approaches • Translation to Decision Criteria is key • Remains to be incorporated into Mgt Process
Summary • Several modeling efforts at various stages along the modeling gradient • Working at both ends of the gradient to make ecosystem-based mgt advice operational • Several research/development activities • A few instances of review in SAW/SARC like process • Not as data limited as elsewhere, but have identified clear data gaps • Tool and software development ongoing
If you think you can or think you can’t, you’re right.- Henry Ford
