Mesoscale productivity fronts and local fishing opportunities in the European Seas

Abstract

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Somatic Condition and Reproductive Potential as a Tandem in European Sardine: An Analysis with an Environmental Perspective in the Northern Adriatic (Gulf of Trieste)

“…Thus, the amount of environmental chlorophyll-a seems to be reflected in Kn, although it does not necessarily translate into the GSI. Thus, the direct available resources (OPFish) (see Supplementary Materials Figure S1 as an example in the area) seem to better illustrate the direct implication that resources have in reproductive terms, as well as SST, in line with Druon et al [53], confirming that in order to project sardine production, the impact of abiotic factors (i.e., temperature) on reproduction should be taken into account, as they seasonally affect their distribution. The prevalence of oocyte atresia together with spawning incidence seem to be positively affected by water temperature, whilst the index of zooplankton production significantly correlates with relative fecundity [62].…”

“…This suggests that chlorophyll-a and fish were not directly related, but a higher chlorophyll-a concentration might be an indicator of favourable conditions for sardines [67,68]. This could be occurring because, as we should not forget, OPFish values are related to the concentration of chlorophyll-a since they are data derived from chlorophyll-a horizontal gradients [53], taking into account that which would be usable for a species such as the sardine.…”

“…The Spearman's rank non-parametric correlation test between pairs of variables was used to explore the relationships between Kn, GSI, HSI, and tissue and mesenteric fat content, along with environmental variables such as sea surface temperatures (SST; • C) (NOAA High Resolution SST data [51]), chlorophyll-a concentrations (Chl; mg•m −3 ) (NASA combined-satellite [52]), and ocean productivity available to fish (OPFish; %) values, which is an index that characterizes 10-20% of the global phytoplankton production that effectively fuels higher trophic levels [53] (Environmental Marine Information System [54]).…”

Copernicus Marine Service Ocean State Report, Issue 5

“…While the habitat weighted by day length slightly better correlates with the mesozooplankton biomass (Spearman's r of 0.935, p ≈ 0, and 0.89, p ≈ 0, respectively), we decided to keep the notion of daily habitat for mesozooplankton and to develop in parallel a more generic index of Ocean Productivity available to Fish (OPFish, first description in Druon 2017). The OPFish index, based on chlorophyll-a gradient preferences for different trophic levels and on day length, is being successfully compared to spatial fisheries data in the European Seas (Druon et al, 2021). Both the mesozooplankton habitat and OPFish index are different notions (habitat and production, respectively) which can be useful metrics depending on the application.…”

Time and spatial trends in landing per unit of effort as support to fisheries management in a multi-gear coastal fishery

“…In the last two decades, new mandatory procedures evolved to improve and standardize fisheries data throughout the EU [6]. Large and more reliable datasets are generated, and statistical modelling can be applied to retrieve crucial fisheries information such as the identification of exploited species and their distribution [7][8][9]. The International Council for the Exploration of the Sea (ICES), the entity responsible for providing advice to the EU on fisheries issues, has identified, as a major objective in its Science Plan, the development of effective mechanisms to use monitoring and surveillance data to support scientific advice [10].…”