@article{fdi:010069360,
  title = {{E}cosystem indicators-accounting for variability in species' trophic levels},
  author = {{R}eed, {J}. and {S}hannon, {L}. and {V}elez, {L}. and {A}koglu, {E}. and {B}undy, {A}. and {C}oll, {M}arta and {F}u, {C}. and {F}ulton, {E}. {A}. and {G}russ, {A}. and {H}alouani, {G}. and {H}eymans, {J}. {J}. and {H}oule, {J}. {E}. and {J}ohn, {E}. and {L}e {L}oc'h, {F}ran{\c{c}}ois and {S}alihoglu, {B}. and {V}erley, {P}hilippe and {S}hin, {Y}unne-{J}ai},
  editor = {},
  language = {{ENG}},
  abstract = {{T}rophic level ({TL})-based indicators are commonly used to track the ecosystem effects of fishing as the selective removal of organisms from the food web may result in changes to the trophic structure of marine ecosystems. {T}he use of a fixed {TL} per species in the calculation of {TL}-based indicators has been questioned, given that species' {TL}s vary with ontogeny, as well as over time and space. {W}e conducted a model-based assessment of the performance of fixed {TL}-based indicators vs. variable {TL}-based indicators for tracking the effects of fishing pressure. {T}his assessment considered three {TL}-based indicators (the trophic level of the landed catch ({TL}c), the marine trophic index ({MTI}) and the trophic level of the surveyed community ({TL}sc)), three fishing scenarios that targeted specific model groups (the low {TL} scenario ({LTL}), the high {TL} scenario ({HTL}) and a scenario encompassing broad-scale exploitation ({ALL})) and ten contrasting marine ecosystems with four types of ecosystem modelling approaches that differ in their structure and assumptions. {R}esults showed that, overall, variable {TL}-based indicators have a greater capacity for detecting the effects of fishing pressure than fixed {TL}-based indicators. {A}cross {TL}-based indicators, {TL}sc displayed the most consistent response to fishing whether fixed or variable species' {TL}s were used, as well as the highest capacity for detecting fishing effects. {T}his result supports previous studies that promote the use of survey-based indicators over catch-based indicators to explore the impacts of fishing on the structure of marine ecosystems. {A}cross fishing scenarios, the low trophic level fishing scenario ({LTL}) resulted in the lowest consistency between fixed and variable {TL}-based indicator responses and the lowest capacity of {TL}-based indicators for detecting fishing effects. {O}verall, our results speak to the need for caution when interpreting {TL}-based indicator trends, and knowledge of the broader context, such as fishing strategies and exploitation history.},
  keywords = {ecosystem indicators ecosystem models ; fishing effects ; fishing ; scenarios ; trophic level-based indicators},
  booktitle = {},
  journal = {{ICES} {J}ournal of {M}arine {S}cience},
  volume = {74},
  numero = {1},
  pages = {158--169},
  ISSN = {1054-3139},
  year = {2017},
  DOI = {10.1093/icesjms/fsw150},
  URL = {https://www.documentation.ird.fr/hor/fdi:010069360},
}