The Influence Of Environmental Factors On Growth And Condition Of Larval Atlantic Herring (Clupea Harengus) In The Saint-Lawrence Middle Estuary In Quebec, Canada | 49132
Journal of Marine Science: Research & Development
Like us on:
Our Group organises 3000+ Global Conferenceseries Events every year across USA, Europe & Asia with support from 1000 more scientific Societies and Publishes 700+ Open Access Journals which contains over 50000 eminent personalities, reputed scientists as editorial board members.
The Atlantic herring population has experienced a strong decline in the Gulf of St. Lawrence, possibly due to overfishing. A subset
of this metapopulation migrates in spring and fall upstream into the St. Lawrence middle estuary to spawn. However, their
recruitment has not been studied in this region for two decades. To better understand recruitment pattern of this part of the herring
population, our first objective was to verify if herring spawning grounds remained in the same area as twenty years ago and to evaluate
the number of larval cohorts produced. Moreover, our second objective was to explore the link between environmental factors and
larval herring growth and condition. Sampling was conducted on 3 small vessels during the summer 2014, using bongo-nets and
a CTD. Environmental factors recorded were temperature, depth, salinity, turbidity and tides. Our results revealed that spawning
grounds were similar to those known 20 years ago. However, reproductive patterns changed, as more larval cohorts appeared over the
summer period. Growth rates of the cohorts varied according to hatching dates, growing faster when hatched in the warmest months.
Nevertheless, comparing the degree days of each cohort revealed that temperature was not the only environmental factor responsible,
suggesting that potentially food availability might be important. Linking the environmental factors of each sampling site identified
different habitats using cluster analysis. We will discuss pattern of larval growth and condition in relation to habitat characteristics in
the view of the overall recruitment of larval herring in the St. Lawrence middle estuary.
Laurence Lévesque is in third year of her Master’s degree in Oceanography at Université du Québec à Rimouki (UQAR-ISMER). She completed a Bachelor’s degree in Biology at McGill University in 2013. She has been for Parks Canada at the Sagenay-Saint-Lawrence Marine Park every summer as a Biology Technician since 2012.