Abundance, distribution and reproduction of the Data-Deficient species (Squalus blainville) around Sardinia Island (central western Mediterranean Sea) as a contribution to its conservation

2021 ◽  
Vol 72 (1) ◽  
pp. 118 ◽  
Author(s):  
Martina Francesca Marongiu ◽  
Cristina Porcu ◽  
Andrea Bellodi ◽  
Rita Cannas ◽  
Pierluigi Carbonara ◽  
...  
Keyword(s):  
Population Decline ◽  
Temporal Trends ◽  
Reproductive Potential ◽  
Western Mediterranean ◽  
Biological Traits ◽  
Abundance Distribution ◽  
Western Mediterranean Sea ◽  
Fishery Data ◽  
Data Deficient

Data-Deficient (DD) species are currently under threat because of the paucity of information regarding their abundance, distribution and biological traits. In this study we analysed temporal trends and bioecological features of the DD shark, Squalus blainville. Biological and fishery data were collected through two different scientific surveys spanning 1994–2018 and commercial hauls around Sardinia Island (central western Mediterranean) from 2008 to 2018. The analysis of temporal trends based on abundance data revealed a significant population decline over time. The late attainment of maturity and low fecundity of S. blainville are suspected to have contributed to making it highly vulnerable to overfishing. No bathymetric segregation by sex and size was found. However, the almost exclusive presence of pregnant females south-west of Sardinia could be due to sexual spatial segregation. This is also supported by histological findings showing long-term sperm storage to ensure the persistence of the species when females and males are separated. The documented decline of this species, its low reproductive potential and similarities in the depth distribution of immature and mature individuals indicate the need for urgent protection plans for S. blainville in Sardinian waters.

scholarly journals Tracking the global reduction of marine traffic during the COVID-19 pandemic

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
David March ◽  
Kristian Metcalfe ◽  
Joaquin Tintoré ◽  
Brendan J. Godley
Keyword(s):  
Large Scale ◽  
Human Mobility ◽  
Western Mediterranean ◽  
Western Mediterranean Sea ◽  
Marine Traffic ◽  
Human Movements ◽  
Exclusive Economic Zones ◽  
Global Impacts ◽  
Economic Zones

AbstractThe COVID-19 pandemic has resulted in unparalleled global impacts on human mobility. In the ocean, ship-based activities are thought to have been impacted due to severe restrictions on human movements and changes in consumption. Here, we quantify and map global change in marine traffic during the first half of 2020. There were decreases in 70.2% of Exclusive Economic Zones but changes varied spatially and temporally in alignment with confinement measures. Global declines peaked in April, with a reduction in traffic occupancy of 1.4% and decreases found across 54.8% of the sampling units. Passenger vessels presented more marked and longer lasting decreases. A regional assessment in the Western Mediterranean Sea gave further insights regarding the pace of recovery and long-term changes. Our approach provides guidance for large-scale monitoring of the progress and potential effects of COVID-19 on vessel traffic that may subsequently influence the blue economy and ocean health.

scholarly journals Dissolved Inorganic Nutrients in the Western Mediterranean Sea (2004–2017)

2019 ◽  
Author(s):  
Malek Belgacem ◽  
Jacopo Chiggiato ◽  
Mireno Borghini ◽  
Bruno Pavoni ◽  
Gabriella Cerrati ◽  
...  
Keyword(s):  
Quality Control ◽  
Mediterranean Sea ◽  
Western Mediterranean ◽  
Inorganic Nutrients ◽  
Marginal Seas ◽  
Western Mediterranean Sea ◽  
Dissolved Inorganic Nutrients ◽  
Climate Shifts ◽  
Quality Control Techniques

Abstract. Long-term time-series are a fundamental prerequisite to understand and detect climate shifts and trends. Understanding the complex interplay of changing ocean variables and the biological implication for marine ecosystems requires extensive data collection for monitoring and hypothesis testing and validation of modelling products. In marginal seas, such as Mediterranean Sea, there are still monitoring gaps, both in time and in space. To contribute filling these gaps, an extensive dataset of dissolved inorganic nutrients profiles (nitrate, NO3; phosphate, PO43−; and silicate, SiO2) have been collected between 2004 and 2017 in the Western Mediterranean Sea and subjected to quality control techniques to provide to the scientific community a publicly available, long-term, quality controlled, internally consistent biogeochemical data product. The database includes 870 stations of dissolved inorganic nutrients sampled during 24 cruises, including temperature and salinity. Details of the quality control (primary and secondary quality control) applied are reported. The data are available in PANGAEA (https://doi.org/10.1594/PANGAEA.904172, Belgacem et al. 2019).

Long‐term sponge stranding along the shores of Sardinia Island (Western Mediterranean Sea)

2019 ◽  
Vol 40 (6) ◽  
Author(s):  
Renata Manconi ◽  
Andrea Padiglia ◽  
Tiziana Cubeddu ◽  
Roberto Pronzato
Keyword(s):  
Mediterranean Sea ◽  
Western Mediterranean ◽  
Western Mediterranean Sea

A Long-term Monitoring Array for Landslide Precursors: A Case Study at the Ligurian Slope (Western Mediterranean Sea)

2012 ◽  
Author(s):  
Sylvia Stegmann ◽  
Nabil Sultan ◽  
Sebastien Garziglia ◽  
Pascal Pelleau ◽  
Ronan Apprioual ◽  
...  
Keyword(s):  
Mediterranean Sea ◽  
Western Mediterranean ◽  
Western Mediterranean Sea ◽  
Long Term Monitoring ◽  
Term Monitoring

scholarly journals Reproductive aspects of the velvet belly lantern shark Etmopterus spinax (Condrichthyes: Etmopteridae), from the central western Mediterranean sea. Notes on gametogenesis and oviducal gland microstructure.

2013 ◽  
Vol 15 (2) ◽  
pp. 313 ◽  
Author(s):  
C. PORCU ◽  
M. F. MARONGIU ◽  
M. C. FOLLESA ◽  
A. BELLODI ◽  
A. MULAS ◽  
...  
Keyword(s):  
Vertical Gradient ◽  
Western Mediterranean ◽  
Sperm Storage ◽  
Sexually Dimorphic ◽  
Oviducal Gland ◽  
Pregnant Females ◽  
Western Mediterranean Sea ◽  
Sperm Storage Tubules ◽  
First Time

In this paper, the reproductive biology of the velvet belly lanternshark Etmopterus spinax was analyzed in Sardinian waters (central western Mediterranean). This species was sexually dimorphic with females growing to a larger size than males. Marked sexual dimorphism in size was also observed along the vertical gradient. Histological analysis of gonads was very useful in assigning macroscopical maturity stages. The investigation on the microstructure of oviducal gland (OG) highlighted four morphofunctional zones with mucous and/or proteic secretions according to the zone and to their specific functions and development. Sperm in the OG was found for the first time in E. spinax. The localization of sperm storage tubules deeper in OG suggested long-term sperm storage, which is in agreement with the long reproductive cycle described. This species matured late, specifically at 80.7% and 79% at the maximum observed size for females and males respectively. Mature specimens were found throughout the year with pregnant females observed in winter and autumn. A low fecundity was observed with a mean ovarian fecundity of 16.5 mature follicles.

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