eCite Digital Repository

Ensemble projections of future climate change impacts on the eastern Bering Sea food web using a multispecies size spectrum model

Citation

Reum, JCP and Blanchard, JL and Holsman, KK and Aydin, K and Hollowed, AB and Hermann, AJ and Cheng, W and Faig, A and Haynie, AC and Punt, AE, Ensemble projections of future climate change impacts on the eastern Bering Sea food web using a multispecies size spectrum model, Frontiers in Marine Science, 7, (MAR) Article 124. ISSN 2296-7745 (2020) [Refereed Article]


Preview
PDF
3Mb
  

Copyright Statement

Copyright © 2020 Reum, Blanchard, Holsman, Aydin, Hollowed, Hermann, Cheng, Faig, Haynie and Punt. Licensed under Creative Commons Attribution 4.0 International (CC BY 4.0) https://creativecommons.org/licenses/by/4.0/

DOI: doi:10.3389/fmars.2020.00124

Abstract

Characterization of uncertainty (variance) in ecosystem projections under climate change is still rare despite its importance for informing decision-making and prioritizing research. We developed an ensemble modeling framework to evaluate the relative importance of different uncertainty sources for food web projections of the eastern Bering Sea (EBS). Specifically, dynamically downscaled projections from Earth System Models (ESM) under different greenhouse gas emission scenarios (GHG) were used to force a multispecies size spectrum model (MSSM) of the EBS food web. In addition to ESM and GHG uncertainty, we incorporated uncertainty from different plausible fisheries management scenarios reflecting shifts in the total allowable catch of flatfish and gadids and different assumptions regarding temperature-dependencies on biological rates in the MSSM. Relative to historical averages (1994–2014), end-of-century (2080–2100 average) ensemble projections of community spawner stock biomass, catches, and mean body size (±standard deviation) decreased by 36% (±21%), 61% (±27%), and 38% (±25%), respectively. Long-term trends were, on average, also negative for the majority of species, but the level of trend consistency between ensemble projections was low for most species. Projection uncertainty for model outputs from ∼2020 to 2040 was driven by inter-annual climate variability for 85% of species and the community as a whole. Thereafter, structural uncertainty (different ESMs, temperature-dependency assumptions) dominated projection uncertainty. Fishery management and GHG emissions scenarios contributed little (<10%) to projection uncertainty, with the exception of catches for a subset of flatfishes which were dominated by fishery management scenarios. Long-term outcomes were improved in most cases under a moderate "mitigation" relative to a high "business-as-usual" GHG emissions scenario and we show how inclusion of temperature-dependencies on processes related to body growth and intrinsic (non-predation) natural mortality can strongly influence projections in potentially non-additive ways. Narrowing the spread of long-term projections in future ensemble simulations will depend primarily on whether the set of ESMs and food web models considered behave more or less similarly to one another relative to the present models sets. Further model skill assessment and data integration are needed to aid in the reduction and quantification of uncertainties if we are to advance predictive ecology.

Item Details

Item Type:Refereed Article
Keywords:climate impacts, projections, modelling, size-structure, uncertainty partitioning, predictive ecology, Arrhenius factor, body size, size-based food web, cumulative effects, commonality analysis
Research Division:Environmental Sciences
Research Group:Climate change impacts and adaptation
Research Field:Ecological impacts of climate change and ecological adaptation
Objective Division:Animal Production and Animal Primary Products
Objective Group:Fisheries - aquaculture
Objective Field:Fisheries - aquaculture not elsewhere classified
UTAS Author:Blanchard, JL (Dr Julia Blanchard)
ID Code:144007
Year Published:2020
Funding Support:Australian Research Council (DP170104240)
Web of Science® Times Cited:8
Deposited By:Ecology and Biodiversity
Deposited On:2021-04-14
Last Modified:2021-05-04
Downloads:2 View Download Statistics

Repository Staff Only: item control page