English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

International audienceComparison on abundance, vertical distribution and reproduction of the cousin species, the boreal Calanus finmarchicus and temperate Calanus helgolandicus was conducted on data collected on 4 cruises in July and August north of the Dogger Bank, North Sea. During this period the water column was highly stratified with a tidally generated deep chlorophyll maximum at 30 m depth. When co-occurring, a separation of the species was evident, where C. finmarchicus preferred colder (9°C) deeper waters while C. helgolandicus stayed in the warmer (16°C) surface waters. Egg production rates were not statistically different between the species, and the population egg production depended primarily on female abundance and was generally higher for C. finmarchicus. Egg production rates of the Calanus spp. were best explained by the abundance of autotrophic and heterotrophic dinoflagellates, flagellates and ciliates. Hatching success remained over 90% at all times but the estimated naupliar survival (N1-6) was only 9%. The chlorophyll maximum supported highest faecal pellet production and egg production at the stations close to the bank. This study shows that C. finmarchicus can remain reproductively active in the North Sea ecosystem longer than previously thought, and with warmer surface temperatures retreat to cooler, deeper waters utilizing the deep chlorophyll maximum. This implies that C. finmarchicus cannot be reliably sampled with the Continuous Plankton Recorder during summer

Biological processes in the North Sea: comparison of Calanus helgolandicus and Calanus finmarchicus vertical distribution and production