Life‐cycle responses of a Mediterranean non‐migratory cyprinid species, the Northern Iberian chub (Squalius carolitertii Doadrio, 1988), to streamflow regulation.

Streamflow is considered a driver of interspecific and intraspecific life‐history differences among freshwater fish. Therefore, dams and related flow regulation can have deleterious impacts on their life cycles. The main objective of this study was to assess existing differences in the growth and reproduction patterns of a non‐migratory fish species (the Northern Iberian chub, Squalius carolitertii, Doadrio, 1988), between nonregulated and regulated watercourses. For 1 year, samples were collected from two populations of Iberian chub, inhabiting rivers with nonregulated and regulated flow regimes. Flow regulation for water storage promoted changes in chub's condition, duration of spawning, fecundity, and oocyte size. However, this non‐migratory species was less responsive to streamflow regulation than other native potamodromous species. Findings from this study are important to understand changes imposed by regulated rivers and can be used to support the implementation of suitable river management practices

Photosynthetic pigments in acid mine drainage: Seasonal patterns and associations with stressful abiotic characteristics

Acid mine drainage represents an extreme type of water pollution. The environments develop especial hydrochemical and ecological characteristics, such as high concentrations of acidity and low biodiversity, with dominance of acidophilic organisms. Ecological criteria are assuming increasing relevance for assessing water quality, including in acid mine drainage-affected systems. Photosynthetic pigments, like chlorophyll, could be considered in this context as they are generally used to estimate phytoplankton biomass. The present work was focused on acid mine drainage and their relationships with chlorophyll a. It was developed in the historic mine of São Domingos (Iberian Pyrite Belt, SW Europe). The methodological approach comprised two sampling campaigns (October and February) to represent seasonal behaviour. The diversity of hydrological conditions was also considered through sampling sites established in the pit lake, acidic lagoons and affected stream. Hydrochemistry and chlorophyll a were analysed. The obtained results revealed very low pH values, with a minimum of 2.1. In general, hydrochemistry indicates higher concentrations of pollutants in summer. One of the sampling point, located in an acidic lagoon, stood out by highest concentrations, presenting maximum of sulfate (6564 mg/L), As (6.26 mg/L), and metals like Al (675 mg/L), Cd (1,30 mg/L), Zn (199 mg/L). These highest concentrations coincided with the maximum concentration of chlorophyll a (113 μg/L). The results suggested that the more contaminated the environment, more chlorophyll a was produced. Factor analyses emphasised the relationships between acid drainage properties and the photosynthetic activity, indicating a strong pH dependency of chlorophyll a production.Patricia Gomes acknowledges FCT (Science and Technology Foundation, Portugal) by the research fellowship under the POCH (Programa Operacional Capital Humano) supported by the European Social Fund and National Funds of MCTES with reference SFRH/BD/108887/2015. This work was co-funded by the European Union through the European Regional Development Fund, based on COMPETE 2020 - project ICT (UID/GEO/04683/2013) with reference POCI-01-0145-FEDER-007690 and by project Nano-MINENV number 029259. The authors are also deeply grateful to the anonymous reviewers for their valuable comments and suggestions

Cephalopod Fisheries in European waters: stock assessment, forecasting and management

4th International Congress on Applied Ichthyology, Oceanography and Aquatic Environment. Hydromedit, Virtual, 4-6 November 2021N

Management for sustainable cephalopod fisheries in Europe: review and recommendations

Cephalopod International Advisory Council Conference, Cephalopods in the Anthropocene: Multiple Challenges in a Changing Ocean, April 2-8, 2022, Sesimbra, PortugalAlthough cephalopod fisheries are of world-wide importance, in Europe catching cephalopods is managed only in small-scale fisheries, at national level, and few stocks are formally assessed. Because cephalopod are not quota species under the EU’s Common Fisheries Policy, there is currently no requirement for assessment or management at European level. Given increasing interest in targeting cephalopods in Europe, there is a risk that they will be fished unsustainably. Although there have been recent review papers on progress in stock assessment and fishery forecasting for commercially fished cephalopods there has been no recent review of cephalopod fishery management. We aim to fill this gap, with a particular focus on European cephalopod fisheries.We review potential barriers to sustainable fishing and reasons why management of cephalopod fisheries differs from that for finfish fisheries, e.g. due to the high inherent volatility and the possibly cyclic nature of year-to-year variation in cephalopod abundance, reflecting their short lifespan, rapid growth and high sensitivity to environmental conditions. We review fishery management approaches in important cephalopod fisheries worldwide (e.g. in the USA, Japan, Falklands, South Africa, Australia and Russia) and current management of small-scale cephalopod fisheries in Europe. We identify knowledge gaps and limitations to current monitoring programmes and stock assessments and discuss the options available for cephalopod fishery management in Europe, considering the suitability or otherwise of catch and effort limits, use of closed areas and seasons, restrictions on sizes caught and types of fishing gear, and the ole of market-based sustainability pathwaysN

Time-integrated 3D approach of late Quaternary sediment-depocenter migration in the Tagus depositional system: From river valley to abyssal plain

Quantification of sediment volumes in continental to deep ocean basins is key to understanding processes of sediment distribution in source-to-sink depositional systems. Using our own and published data we present the first quantification of sediment-volume changes in basins along the course of a major southwest European river during the deglaciation. The salient points of this quantitative record in the Tagus and equivalent North Atlantic basins show crucial roles for sea level, climate and land-use in the distribution of sediments. The bypass of sediments starved the Tagus basins, and subsequently sedimentation mainly occurred on the Tagus Abyssal Plain during the sea-level lowstand of the Last Glacial Maximum. The main sediment depocenter rapidly shifted via the continental shelf to the Lower Tagus Valley during sea-level rise in the deglaciation period. Finally, the main sediment depocenter shifted further landward into the Lower Tagus Valley during sea-level high stand in the Holocene. During the high-stand phase (last 7 ky), sediment flux increased up to 2.5 times, due to climate and land-use changes. The average catchment denudation rate during the last 12 ky (0.04–0.1 mm/y) is in agreement with those of other European catchments. Our study clearly demonstrates the added value of detailed knowledge of 3D depocenter distribution, size and chronology. This allowed us to identify an increased sediment flux during the last 7 ky, which was not identified using local observations from boreholes alone. The uniqueness of the Tagus depositional system lies in the combination of a large accommodation space in the bedrock-confined Lower Tagus Valley, the steep lowstand-surface gradient and the narrow continental shelf with canyons indenting the shelf break

Stylet (vestigial shell) size in Octopus vulgaris (Cephalopoda) hatchlings used to determine stylet nucleus in adults

7 páginas, 1 tablas, 3 figurasThe estimation of age and growth of cephalopod stocks is a key issue for their sustainable management. Recently, several studies have successfully validated the daily deposition of growth rings in the vestigial shell or stylets of several octopus species. Octopus vulgaris eggs were incubated at two different temperatures, 18 and 22°C, until hatching to determine stylet size at hatching and assess the effect of temperature in the stylet dimensions. The 3-day-old hatchlings were sectioned transversally and 6 μm sections were stained to enhance the stylet position and visibility. The sections were observed under transmitted light microscopy at a magnification of 1000×, and the stylets identified as blue/green structures inside the mantle–funnel retractor muscle. The transversal sections of the whole paralarvae allowed the diameter of the embryonic stylet of an octopus species to be measured for the first time. The mean stylet diameter in 3-day-old paralarvae is 3.99 μm independently of the thermal conditions. Moreover, significant differences in stylet size between captive and wild paralarvae were observed; the latter showed significantly larger stylets, an indication that they are over 3 days old. Our results also indicate that the stylet nucleus is much smaller than previously thought based on measurements in stylets of juveniles and adultsThis study was supported by the projects CAIBEX (CTM2007-66108-C02-01) and LARECO (CTM2011-25929). The MultiNet® sampler used to collect wild paralarvae was funded by FEDER funds. The Portuguese Foundation for Science and Technology (FCT) supported this study through a PhD grant to Sílvia Lourenço (grant number SFRH/BD/44182/2008) and the project grant PTDC/BIA-BEC/103266/2008 to Rui Rosa.Peer reviewe

Navigating Global Assignments: An HR Perspective with Essential Checklists for Success

This article will provide practical guidance to help HR successfully implement and manage global assignments for companies operating internationally