0000000000172182
AUTHOR
G. Turco
Sandbar shark aggregation in the central Mediterranean Sea and potential effects of tourism
An aggregation of sandbar sharks Carcharhinus plumbeus occurs every summer around the remote uninhabited islet of Lampione (Pelagie Islands Marine Protected Area, south-western Mediterranean Sea), attracting an increasing number of tourists for a shark watching experience. Despite the ecological and socio-economic importance of this rare occurrence in Mediterranean waters, there is a lack of scientific data and lack of information as to the potential impact of tourist activities on the presence and behaviour of this shark species. Using baited underwater videos, this study provides the first assessment of this shark aggregation, as well as a preliminary evaluation of the potential effects t…
Volcanic CO2 seep geochemistry and use in understanding ocean acidification
AbstractOcean acidification is one of the most dramatic effects of the massive atmospheric release of anthropogenic carbon dioxide (CO2) that has occurred since the Industrial Revolution, although its effects on marine ecosystems are not well understood. Submarine volcanic hydrothermal fields have geochemical conditions that provide opportunities to characterise the effects of elevated levels of seawater CO2 on marine life in the field. Here, we review the geochemical aspects of shallow marine CO2-rich seeps worldwide, focusing on both gas composition and water chemistry. We then describe the geochemical effects of volcanic CO2 seepage on the overlying seawater column. We also present new g…
Changes in fish communities due to benthic habitat shifts under ocean acidification conditions
Ocean acidification will likely change the structure and function of coastal marine ecosystems over coming decades. Volcanic carbon dioxide seeps generate dissolved CO2 and pH gradients that provide realistic insights into the direction and magnitude of these changes. Here, we used fish and benthic community surveys to assess the spatio-temporal dynamics of fish community properties off CO2 seeps in Japan. Adding to previous evidence from ocean acidification ecosystem studies conducted elsewhere, our findings documented shifts from calcified to non-calcified habitats with reduced benthic complexity. In addition, we found that such habitat transition led to decreased diversity of associated …
Impiego dei BRUV (Baited Remote Underwater Video) per la valutazione del popolamento ittico nell'area marina protetta Capo Gallo-Isola delle Femmine (Palermo)
A Baited Remote Underwater Video (BRUV) system was used to assess fish assemblages on detritic bottoms (40 m) inside and outside the Capo Gallo - Isola delle Femmine MPA. Our study investigated the suitability of Baited Remote Underwater Video to describe fish (relative) abundance and diversity between sites at different protection levels. The fish assemblages relative abundance and species richness significantly differed between the three different location (A, B e CTL) considered. The largest difference occurred at CTL site position outside the MPA, where 2-fold increase in the number of species was recorded relative to the A and B sites.
Environmental DNA effectively captures functional diversity of coastal fish communities.
Robust assessments of taxonomic and functional diversity are essential components of research programmes aimed at understanding current biodiversity patterns and forecasting trajectories of ecological changes. Yet, evaluating marine biodiversity along its dimensions is challenging and dependent on the power and accuracy of the available data collection methods. Here we combine three traditional survey methodologies (underwater visual census strip transects [UVCt], baited underwater videos [BUV] and small-scale fishery catches [SSFc]), and one novel molecular technique (environmental DNA metabarcoding [eDNA]-12S rRNA and cytochrome oxidase subunit 1 [COI]) to investigate their efficiency and…