Inter-annual cascade effect on marine food web: A benthic pathway lagging nutrient supply to pelagic fish stock

PLoS One. 2017 Sep 8;12(9):e0184512. doi: 10.1371/journal.pone.0184512. eCollection 2017.

Abstract

Currently, spatial and temporal changes in nutrients availability, marine planktonic, and fish communities are best described on a shorter than inter-annual (seasonal) scale, primarily because the simultaneous year-to-year variations in physical, chemical, and biological parameters are very complex. The limited availability of time series datasets furnishing simultaneous evaluations of temperature, nutrients, plankton, and fish have limited our ability to describe and to predict variability related to short-term process, as species-specific phenology and environmental seasonality. In the present study, we combine a computational time series analysis on a 15-year (1995-2009) weekly-sampled time series (high-resolution long-term time series, 780 weeks) with an Autoregressive Distributed Lag Model to track non-seasonal changes in 10 potentially related parameters: sea surface temperature, nutrient concentrations (NO2, NO3, NH4 and PO4), phytoplankton biomass (as in situ chlorophyll a biomass), meroplankton (barnacle and mussel larvae), and fish abundance (Mugil liza and Caranx latus). Our data demonstrate for the first time that highly intense and frequent upwelling years initiate a huge energy flux that is not fully transmitted through classical size-structured food web by bottom-up stimulus but through additional ontogenetic steps. A delayed inter-annual sequential effect from phytoplankton up to top predators as carnivorous fishes is expected if most of energy is trapped into benthic filter feeding organisms and their larval forms. These sequential events can explain major changes in ecosystem food web that were not predicted in previous short-term models.

MeSH terms

  • Animals
  • Aquatic Organisms*
  • Bivalvia
  • Ecosystem
  • Fishes
  • Food Chain*
  • Phytoplankton
  • Temperature

Grants and funding

Financial support was provided by Fundação Carlos Chagas Filho de Amparo à Ciência (FAPERJ – E26/110.220/2011) (LDAF) through the “Estrutura e Dinâmica Trófica em Assembléias Micropelágicas Marinhas em Área de Ressurgência no Norte Fluminense” project, and also by Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) through “Programa de Pesquisa Ecológica de Longa Duração PELD - RECA” (RC). (Proc. 441525/2016-4). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.