Document of bibliographic reference 368320

BibliographicReference record

Type

Bibliographic resource

Type of document

Journal article

BibLvlCode

AS

Title

Seasonal upwelling influence on trophic indices of mesozooplankton in a coastal food web estimated from δ¹⁵N in amino acids

Abstract

Mesozooplankton communities in upwelling ecosystems are known to be influenced by seasonal upwelling enhancing primary productivity. However, the extent to which changes in trophic dynamics of mesozooplankton are driven by variations in the baseline of nitrogen or in the trophic position (TP) is poorly understood. We used nitrogen stable isotopes (δ¹⁵N) in bulk and in specific amino acids (CSIA-AA), as well as the taxonomic composition of mesozooplankton samples collected monthly during two full years, to investigate whether the upwelling intensity affects the isotopic N baseline and other trophic indices at the community level in the coastal system off NW Iberian Peninsula. We hypothesized that enhanced phytoplankton productivity during upwelling events would lead to a shorter and more efficient food web. Upwelling induced mesozooplankton herbivory (by increasing the abundance and biomass of omnivorous-herbivorous copepods and other taxa), resulting in a linear decrease of TPGlx (estimated using Glx = glutamic acid + glutamine, which mainly involves metazoan links) from downwelling to upwelling situations. In contrast, TPAla (estimated using alanine, which also reflects microbial trophic pathways) was highest in low-moderate upwelling and decreased with upwelling strength. Thus, an optimal coupling between metazoan and microbial food webs was reached at low-moderate upwelling intensities when the microbial contribution was ca. 25 %, while this contribution decreased (<15 %) either during downwelling or during strong upwelling. However, the significance of differences in mean values of TP and zooplankton composition was small due to the rapid succession of upwelling and downwelling events. Our results illustrate how a combination of CSIA-AA and community data can provide valuable information on rapid changes in mesozooplankton food web structure in highly dynamic upwelling systems.

WebOfScience code

https://www.webofscience.com/wos/woscc/full-record/WOS:001104106800001

Bibliographic citation

García-Seoane, R.; Viana, I.G.; Bode, A. (2023). Seasonal upwelling influence on trophic indices of mesozooplankton in a coastal food web estimated from δ¹⁵N in amino acids. Prog. Oceanogr. 219: 103149. https://dx.doi.org/10.1016/j.pocean.2023.103149

Topic

Marine

Is peer reviewed

true

Access rights

open access

Is accessible for free

true