Grant: Discovery Grants Program - Individual

Climate change is markedly and rapidly impacting natural ecosystems and resources, including fisheries. In Canada, the single-most important fishery (value and employment) is that for the American lobster. Whereas lobster landings in Canada are at an all-time high, the species is experiencing rapid changes in distribution and abundance, with stocks in the "south", i.e., Bay of Fundy (BoF), showing early signs of a downturn and those in the "north", i.e., Gulf of St. Lawrence (GoStL), showing increases in abundance and northern range. Recent research provides strong evidence that these changes are partly related to climate-driven variation in the survival of young lobsters between their hatch from the female brood and their settlement onto the seafloor, although the mechanisms involved are debated. The goal of my NSERC Discovery program over the next 5 years is to determine the extent to which the early life history success of lobster explains current (and potentially future) spatial and temporal trends in the species' demography, and to elucidate the mechanisms involved. This research does not qualify as "Indigenous Research", as defined by NSERC. We will test hypotheses, mostly founded in evolutionary theory, concerning interactions between environmental conditions and phenotypic attributes of lobster (1) females with eggs, (2) embryos, and (3) larvae that may affect the likelihood of young lobsters successfully recruiting to the seafloor. We will conduct comparative and manipulative studies in the laboratory and in the field, in the BoF and the GoStL, including (i) raising lobster embryos to generate region-specific temperature-based functions of embryo development, (ii) satellite tagging to quantify the thermal history of ovigerous females (and their embryos) in the 1-2 months preceding hatch, (iii) laboratory experiments to assess the contribution of "plankton cues" to the hatch time of lobster embryos, (iv) plankton sampling and DNA metabarcoding to assess the zooplankton "prey field", diet, and prey preference of lobster larvae, (v) laboratory experiments to quantify growth and survival of lobster larvae in the presence of different species of zooplankton, (vi) analyzing government data bases to determine if variation in lobster benthic recruitment in the BoF and GoStL over the past 20-30 years is related to changes in zooplankton communities, (vii) using data from ii and iv to determine whether movements of ovigerous females increase the likelihood of larvae encountering profitable zooplankton prey. This research will generate some of the most comprehensive data on geographic phenotype-environment associations of a non-model marine organism, and some of the only such data involving early life stages (embryos and larvae) of marine invertebrates. It will also provide new insights into the factors and mechanisms underlying population trends in a species that is of utmost socio-economic importance to coastal communities in eastern Canada.