Spatio-Temporal Variation in Effects of Upwelling on the Fatty Acid Composition of Benthic Filter Feeders in the Southern Benguela Ecosystem: Not All Upwelling Is Equal

Abstract

Variability in mesoscale nearshore oceanographic conditions plays an important role in the distribution of primary production and food availability for intertidal consumers. Advection of nutrient rich waters by upwelling usually allows the proliferation of diatoms, later replaced by dinoflagellates. We examined upwelling effects on the fatty acid (FA) signature of a benthic intertidal filter feeder to identify its response to pulsed variability in food availability. The study took place in two contrasting seasons and at two upwelling and two non-upwelling sites interspersed within the southern Benguela upwelling system of South Africa. We investigated the FA composition of the adductor muscles and gonads of the mussel Mytilus galloprovincialis to assess how FA are apportioned to the different tissues and whether this changes between upwelling and non-upwelling conditions. In situ temperature loggers used to identify upwelling conditions at the four sites indicated that such events occurred only at the upwelling centres and only in summer. Tissues differed strongly, with gonads presenting a higher proportion of essential FAs. This could reflect the faster turnover rate of gonad tissue or preferential retention of specific FA for reproductive purposes. FA composition did not vary as a direct function of upwelling, but there were strong dissimilarities among sites. Upwelling influenced mussel diets at one upwelling site while at the other, the expected signature of upwelling was displaced downstream of the core of upwelling. Condition Index (CI) and Gonad Index (GI) differed among sites and were not influenced by upwelling, with GI being comparable among sites. In addition, FA proportions were consistent among sites, indicating similar food quality and quantity over time and under upwelling and non-upwelling conditions. This suggests that the influence of upwelling on the west coast of South Africa is pervasive and diffuse, rather than discrete; while nearshore retention or advection of upwelled water is critical and site-specific so that the effects of upwelling differ even among sites categorised as upwelling centres.

Bilingual and Monolingual Idiom Processing Is Cut from the Same Cloth: The Role of the L1 in Literal and Figurative Meaning Activation

“…In this case, L2 listeners should always respond faster to literal meaning, as it is generally more salient for L2 listeners. While our L2 results also produced this general effect, it is repeated in our L1 findings—something we would not expect if we assume that L1 listeners should often find the figurative meaning to be more salient (Giora, 1997 , 2002 ). While the availability of meaning does confirm that literal constituent meaning plays a role in processing idioms, we are not prepared to assume a necessary priority.…”

“…For instance, both familiarity (see e.g., Libben and Titone, 2008 for an overview) and a strongly biasing figurative context (Colombo, 1993 ; Cacciari et al, 2007 ; Cacciari and Corradini, 2015 ) have been shown to affect access to figurative meaning. In fact, Giora ( 1997 , 2002 ) suggests that saliency—conventionality, frequency, familiarity, contextually supported—rather than an individual factor is most relevant in idiomatic processing. Instead of differentiating between literal and non-literal processing, she separates salient processing from non-salient processing: Saliency facilitates processing as salient meanings are retrieved immediately and directly, while non-salient meanings are retrieved through default language processing and integration processes.…”

Omega-3 Pathways in Upwelling Systems: The Link to Nitrogen Supply

“…The supply of omega-3 is expected to change in the near future as a consequence of climate change (e.g., Hixson and Arts, 2016;Colombo et al, 2020), with implications for meeting the omega-3 requirements of a growing human population that is predicted to reach 11 billion by 2100 (Roser, 2013). Major climate-driven factors relevant to omega-3 production include warming (Hixson and Arts, 2016), ocean acidification (Dörner et al, 2020), and variability in upwelling intensity (Puccinelli et al, 2016a).…”

Cultivo suspendido de la ostra perlera alada Pteria colymbus (Röding), en diferentes condiciones hidrográficas y métodos de cultivo

“…The Southern Caribbean Sea, and particularly the northeastern coast of Venezuela, is under the influence of coastal upwelling (Okuda et al, 1978;Jury, 2018). The high concentrations of nutrients during particular periods of the year stimulates the productivity of phytoplankton, and it has been hypothesized that the cycles of upwelling and relaxation (non-upwelling) modulate the availability of planktonic food for some benthic species, influencing, in turn, their growth patterns (Puccinelli et al, 2016). The predominant trade winds blow parallel to the coast and the topography of the continental shelf favor the upwelling of sub-tropical waters rich in nutrients, with a seasonal intensification between December and April (Müller-Karger and Aparicio-Castro, 1994, Freites et al, 2017) Recently, Rueda-Roa et al (2018 showed the presence of a mid-year upwelling cycle (June-August) in the northeastern coast of Venezuela, attributed to the intensification of the Caribbean Current during this period.…”