Marine Stewardship Council Science Series Model and data adequacy for Marine Stewardship Council key low trophic level species designation and criteria and a proposed new assessment index Tim Essington1 and Éva E. Pláganyi2 1 University of Washington School of Aquatic and Fishery Sciences. Box 355020 Seattle WA 98195 U.S.A. [email protected] 2 Commonwealth Scientific and Industrial Research Organisation (CSIRO) Marine and Atmospheric Research, Wealth from Oceans Flagship, PO Box 2583, Brisbane, QLD, 4001 Australia. eva.plaganyi- [email protected] Abstract There is a great opportunity to use ecological models to assist with identifying possible issues and management measures appropriate to low trophic level (LTL) fisheries. Specifically, there is potential to use models to identify important LTL species and to assess the impacts of different fishing pressures on ecosystems. The ability of models to achieve these aims is a function of the quality data used and the detail of the food-web. This report demonstrates the significant effects of aggregating species into guilds or functional groups on the ability of models to identify connectance levels (a key metric for identifying vulnerable LTL ecosystems). A new index is proposed that appears to better identify situations where exploitation of LTL species can impact on ecosystems. Citation: Essington T and Pláganyi EE (2013) Model and data adequacy for Marine Stewardship Council key low trophic level species designation and criteria and a proposed new assessment index. Marine Stewardship Council Science Series 1: 171 – 191. Date submitted: January 2013 | Date published: November 2013 Disclaimer: The Marine Stewardship Council Science Series has been commissioned by Marine Stewardship Council (MSC) as part of its goal to extend scientific research and understanding of marine ecosystems and fisheries. The views expressed in this publication do not necessarily reflect the views of the MSC. The MSC certification program changes over time; every attempt is made to ensure all details within this paper are accurate at the time of publication. An internal review process has been established to ensure as far as possible the accuracy, content, completeness, legality and reliability of the information presented. For full detail of the review process visit: www.msc.org/business-support/science-series/science- series-review-process Copyright: © The Author 2013. Published by Marine Stewardship Council Science Series. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly cited. 171 Model and data adequacy for MSC key LTL species designation and criteria and a proposed new assessment index Introduction Low trophic level (LTL) species are characteristically small, pelagic and planktivorous fish that have a shoaling habit. They account for over 30% of fisheries landings and are often of critical importance as food fish to economically important species higher up the food chain (Smith et al., 2011). With an awareness of their importance has come a realisation of the need to assess their relationship with fisheries with regard to both the impact of removal or excessive proportions of LTLs on predators and vice versa (Yemane et al. 2009). This report reviews data and models available from fisheries currently in the Marine Stewardship Council (MSC) program or under assessment to evaluate them against the key low trophic level (LTL) requirements, Performance Indicator (PI) 1.1.2. These requirements specify: (A) a method to identify stocks as key LTL and (B) default upper bounds for limit and target biomass reference points for key LTL stocks. Biomass reference points may fall below default levels only when there is credible scientific information indicating they would not induce moderate (>40% decline) effects on more than 15% of the species in the ecosystem or have severe (>70% decline) effects on any individual species. Thus, LTL fisheries must pass through two filters during assessment: Filter 1 to identify key LTL species and Filter 2 to set biomass reference points. The report screens fisheries for data and model adequacy relevant for these two filters, and provides guidance for Conformity Assessment Bodies (CABs) on how to assess fisheries against these filters. This report also explores the extent to which Filter 1 correctly identifies key LTL species and distinguishes them from species for which depletion has less significant impacts. Methods Fisheries in the MSC program and in assessment were surveyed. The survey identified 32 (twenty-five certified; seven in assessment) that would be flagged as default key LTL species based on taxonomy (for example, fisheries targeting herrings, sardines, anchovies and krill). Many of the fisheries target the same stocks so the total number of stocks in the program is much smaller. Table 1. List of stocks and ecosystems in analysis (stocks marked * assumed to be key LTL). Stock Certification status Ecosystem/Area Anchoveta Pre-Assessment Humboldt Current Sandeel*, Herring, Sprat* Herring certified North Sea Capelin* Unknown Barents Sea Menhaden Unknown Chesapeake Bay Sardine, Anchovy* Unknown Benguela Herring, Sprat In assessment Baltic Sea Herring, Sardine, Sprat Certified/ In assessment Celtic Sea Sardine, Thread Herring Certified/ In assessment Gulf of California Krill* Certified Southern Ocean Cornwall Sardine, Sprat, Herring Certified/ In assessment/ Unknown English Channel Southwest Atlantic (Argentine and Uruguayan seas) in Food and Anchovy Certified Agriculture Organisation (FAO) statistical area 41 International Council for the Mackerel Certified Exploration of the Sea (ICES) areas II, III, IV, V & VI, VII, VIII, XII and XIV Herring Certified Atlanto-Scandian Sardine Certified Bay of Biscay Sardine Unknown California Current Sardine Unknown Canary Current Gulf Menhaden, Bay Anchovy* Unknown Gulf of Mexico Small Pelagics (Sardinops, other) Unknown Southeast Australia 172 Model and data adequacy for MSC key LTL species designation and criteria and a proposed new assessment index Evaluation of the existing models for several stocks was undertaken (Table 1). This list details fisheries that are currently in the MSC program (in assessment or certified), may choose to pursue certification in the future or that are informative as well-known case studies where predator dependencies have been documented. The review spans 18 ecosystem models that cover 27 LTL stocks covering a range of years between 1990 and 2007 (Table 2). Table 2. Summary of model sources used in analysis. Stock(s) Model ecosystem Reference Atlanto-Scandian Herring Norwegian Sea and Barents Sea Dommasnes et al. (2001) Clupea harengus 1950-2000 Argentina Anchovy North and Central Patagonia Koen-Alonso & Yodzis (2005) Engraulis anchoita 1900-2000 Southeastern Australia Sardine S.E. Australia Shelf and Slope Bulman et al. (2011) Sardinops sagax 1994-2002 Baltic Sea Herring and Sprat Baltic Sea Harvey et al. (2003) C. harengus & Sprattus sprattus 1974-2000 Barents Sea Capelin Barents Sea Blanchard et al. (2002) Mallotus villosis 1973-1999 California Current Sardine Northern California Current Field et al. (2006) Sardinops sagax 1960-2004 Bay of Biscay Sardine Bay of Biscay Lassalle et al. (2011) Sardina pilchardus 1996-2003 Canary Current Sardine Arguin Bank Sidi and Diop (2004) Sardinops sagax 1988-1998 Celtic Sea Sprat and Herring Celtic Sea Guénette & Gascuel (2009) C. harengus & S. sprattus 1980-2006 Chesapeake Bay Menhaden Chesapeake Bay Christensen et al. (2009) Brevoortia tyrannus 1950-2002 Gulf of California Sardine and et al Thread Herring Northern Gulf of California Morales-Zarate . (2004); et al S. sagax & Opisthonema libertate Ecopath only, 1985-2008 Ainsworth . (2011) Gulf of Mexico Menhaden and Bay Gulf of Mexico Anchovy Walters et al. (2008) B. patronus & Anchoa mitchilli 1950-2004 et al et al Humboldt Current Anchovy North Humboldt Current Guénette, . (2008); Marzloff . et al et al E. ringens 1953-1984, 2000-2006, 1950- (2009); Smith . (2011);Tam . 2009,1995-1998, 1995-2004 (2008); Taylor et al. (2008) Northeast Atlantic Mackerel North Sea Mackinson and Daskalov (2007) Scomber scombrus 1973-2003 North Sea Sprat, Herring, Sandeel and Mackerel North Sea Mackinson & Daskalov (2007) Sprattus sprattus, Clupea harengus, 1973-2003 S. Scombrus South Africa Sardine and Anchovy Southern Benguela Shannon et al. (2003, 2004, 2008); S. sagax, Engraulis ecrisicolus 1980-1997, 1978-2002, 1978-2003, Shin et al. (2004); Smith et al. (2011) Southern Ocean Krill Euphausia superba Various Plaganyi & Butterworth (2012); et al 1970-2006, 1970-2007, 1970-2007 Watters . (2005, 2008) Western English Channel Sprat Western English Channel and Herring Araújo et al. (2005) S. sprattus, C. harengus 1973/1994 * See also Hill (2013) and Watters et al. (2013) 173 Model and data adequacy for MSC key LTL species designation and criteria and a proposed new assessment index Model and data adequacy for Filter 1 and Filter 2 In order to accurately identify key LTL species a set of appropriate evaluation criteria were developed (Table 3). The aim was to try to evaluate the utility of the models for assessing impacts of LTL fisheries – despite the fact that they were not originally designed with this in mind. Models are built around the data available, both temporally and spatially. This can lead