Research in the Mercier Lab
Research in the Mercier Lab examines the interactions between benthic organisms and environmental factors at various scales, typically combining field samplings and experimental trials with microscopic/cellular and biochemical analyses. Breakthroughs in biology, ecology, evolution and conservation made over the past several years were published in prominent journals and have received media coverage, including:
- first evidence of lunar rhythms in the reproduction of deep-water taxa;
- first report of allogeneic fusion (chimerism) in a unitary organism and in deuterostomes;
- first demonstration of a functional relationship between fish larvae and deep-sea corals.
Marine ecology and reproductive cycles
Our discovery of lunar components in the reproduction of deep-water taxa (J Biol Rhythms 2011) drew attention to overlooked proxies of lunar cues in the disphotic zone (~200-1200 m). We also evidenced environmentally-mediated breeding and growth in deep-water taxa (Coral Reefs 2011; Mar Biol 2011, 2014; Mar Ecol 2015; Deep-Sea Res 2011, 2014, 2015, 2017), of special significance in view of anticipated changes in the seasonal timing (phenology) of life-history events caused by climate change (shift in phase relationship between photoperiod and temperature). A quantitative index of oogenesis (Mar Biol 2012; Estuar Coast Shelf Sci 2014) was developed to facilitate the statistical analysis of gametogenic synchrony. Finally, bathymetric shifts in maternal reproductive investment were evidenced (Deep-Sea Res 2013).
Biology of early life stages
Our research in functional and evolutionary ecology has led to the discovery of fusion among brooded offspring (Proc R Soc B 2011) which became the first direct evidence of chimerism in a unitary aclonal organism. It was later highlighted as a driver of offspring size variations in live-bearing organisms (Am Nat 2012). Our most recent discovery in this field is of allogeneic fusion at the embryonic stage in a unitary deuterostome (Proc R Soc B 2018). Several other papers were published on the drivers of offspring phenotypes (Ecol Evol 2015; PLoS One 2016; Adv Mar Biol 2017) and on larval ecology (Mar Biol 2017; JEMBE 2018). There was also a key publication (Glob Ecol Biogeogr 2013) and co-authored book chapters on paradigms linking larval modes and pelagic duration (central to population connectivity in marine ecosystems).
Resources management and conservation
An applied segment of our work contributes to conservation and management programs. The lab's expertise on sea cucumbers has long been drawn upon in that context, leading to a global review of sea cucumber fisheries (Fish Fish 2013) and a paper on their conservation (Proc R Soc B 2014). Many graduate projects have focused on the biology of sea cucumbers to help assess the sustainability of the stocks and how they should best be managed (Mar Biol 2011; PLoS One 2015; Fish Res 2016), and to explore their potential in aquaculture (Aquac Res 2016; Aquaculture 2018). A close collaboration with Chinese colleagues had led to the edition of a 24-chapter book on sea cucumber (Academic Press 2015) and the publication of the sea cucumber genome (PLoS Biology 2017). In another area, a discovery made in the lab provided support for the classification of deep cold-water corals as essential fish habitat (Front Ecol Environ 2012). This finding was reported in the media and a World Wildlife Fund document (WWF Sep 2012) on vulnerable ecosystems, in support of NAFO-recommended encounter protocols.
Effects of pollution and climate change
The newest segment of our research examines the response of various marine taxa to climate change, i.e. ocean acidification (MEPS 2016; Deep-Sea Res 2017), as well as to chemical pollution (Ecotoxicol Env Safety 2018) and to hydostatic pressure (Mar Biol, under review).