Functional roles of an engineer species for coastal benthic invertebrates and demersal fish

• Published in: Ecology and Evolution
• Main Authors: Chaalali, Aurélie, Brind'Amour, Anik, Dubois, Stanislas. F., Le Bris, Hervé
• Other Authors: Écologie et santé des écosystèmes (ESE), Institut National de la Recherche Agronomique (INRA)-AGROCAMPUS OUEST, Écologie et Modèles pour l'Halieutique (EMH), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Laboratoire d'Ecologie Benthique Côtière (LEBCO), Dynamiques des Écosystèmes Côtiers (DYNECO), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2017
• Subjects: concarneau south brittany; trisopterus-minutus l; cod gadus-morhua; stable isotopes; length-weight relationships; Haploops nirae; isotopic diversity; indices; nirae kaim-malka; ecosystem; engineers; feeding ecology; poor-cod; population-structure; coastal nurseries; fish community; stable; isotopes; [SDV]Life Sciences [q-bio]; Gadus morhua
• Online Access: https://hal.science/hal-01608028; https://hal.science/hal-01608028/document; https://hal.science/hal-01608028/file/Le_Bris_2017_fonctionn.pdf; https://doi.org/10.1002/ece3.2857

Through their tissues or activities, engineer species create, modify, or maintain habitats and alter the distribution and abundance of many plants and animals. This study investigates key ecological functions performed by an engineer species that colonizes coastal ecosystems. The gregarious tubiculous amphipod Haploops nirae is used as a biological model. According to previous studies, the habitat engineered by H.nirae (i.e., Haploops habitat) could provide food and natural shelter for several benthic species such as benthic diatoms belonging to the gender Navicula, the micrograzer Geitodoris planata, or the bivalve Polititapes virgineus. Using data from scientific surveys conducted in two bays, this study explored whether (1) the Haploops sandy-mud community modifies invertebrate and ichthyologic community structure (diversity and biomass); (2) H.nirae creates a preferential feeding ground; and (3) this habitat serves as a refuge for juvenile fish. Available Benthic Energy Coefficients, coupled with more traditional diversity indices, indicated higher energy available in Haploops habitat than in two nearby habitats (i.e., Sternaspis scutata and Amphiura filiformis/Owenia fusiformis habitats). The use of isotopic functional indices (IFIs) indicated (1) a higher functional richness in the Haploops habitat, related to greater diversity in food sources and longer food chains; and (2) a higher functional divergence, associated with greater consumption of a secondary food source. At the invertebrate-prey level, IFIs indicated little specialization and little trophic redundancy in the engineered habitat, as expected for homogenous habitats. Our results partly support empirical knowledge about engineered versus nonengineered habitats and also add new perspectives on habitat use by fish and invertebrate species. Our analyses validated the refuge-area hypothesis for a few fish species. Although unique benthic prey assemblages are associated with Haploops habitat, the hypothesis that it is a preferential feeding area was ...