Calculating a Drop in Carbon Emissions in the Strait of Gibraltar (Spain) from Domestic Shipping Traffic Caused by the COVID-19 Crisis

As a consequence of the COVID-19 pandemic, the Spanish government declared a State of Emergency, and domestic passenger ship traffic was restricted in Spanish ports. This manuscript presents scenarios of emissions from domestic shipping traffic in the seas of the Strait of Gibraltar (Spain) over three months of the COVID-19 pandemic. Emissions were estimated for only 90 days of the pandemic, and two scenarios were studied: emissions while vessels were berthed at the Algeciras Port and emissions as a consequence of the interruption of passenger ship transportation in the Strait of Gibraltar. To this end, the authors' own model was used, which has near zero uncertainties. This model was used for the first time in this study and takes into account both meteorological and sea condition parameters, as well as the efficiency of the propulsion system. The manuscript concentrates on the emissions of greenhouse gases (GHGs), nitrogen oxides (NOx), sulphur oxides (SOx), carbon dioxide (CO2), and particulate matter (PM) from six Ro-Pax ships that ceased to operate. The main finding is that as a consequence of the pandemic, reductions of up to 12% were found in the Strait of Gibraltar in all the pollutants and GHGs when taking into account all international traffic, while the decrease in emissions from domestic traffic only reached 51%

Nutritional condition of Argentine anchovy Engraulis anchoita larvae in connection with nursery ground properties

12 pages, 11 figures, 6 tablesNutritional condition of anchovy Engraulis anchoita larvae from Northern Argentinean sea was assessed and compared in three areas characterized by dissimilar oceanographic features (estuarine, mixed and shelf waters). Morphometrical, histological and biochemical (RNA/DNA) indexes were used and larvae were compared through different developmental stages. Multivariate analyses performed on normalized morphometric variables showed that larvae from mixed waters where characterized by higher body depths; variables that indicate a better nutritional condition. Mean histological condition index obtained for larvae at intermediate developmental stages was significantly lower in estuarine waters than those estimated with samples from mixed or shelf waters. Anchovy larvae from the mixed water area showed a higher slope in the log RNA versus log DNA relationship than larvae from the other areas, which indicates that the former were in better condition. Also, standardized RNA/DNA index (RNA/DNAs) resulted slightly better in mixed waters than in shelf area, for larvae at intermediate developmental stages, but due to the high variability of RNA/DNA ratio, no significant differences were found between areas. Finally, using literature equations relating RNA/DNAs, temperature and growth, growth rate and growth performance were estimated. Mean growth performance did not differ between areas and was temperature independent. In conclusion, larval condition was relatively high at all stations, but our results suggested that it was slightly better in frontal areas characterized by water masses with intermediate salinities. We also provide evidence that anchovy larvae might not be food limited in any of the studied areasThis work was supported by the INIDEP and the CONICET. M.V. Diaz acknowledges MAEC-AECI Fellowship support that allowed transportation to Barcelona in order to analyse RNA/DNA contents. This is INIDEP contribution no. 1638Peer reviewe

Nutritional condition of Argentine anchovy Engraulis anchoita larvae in connection with nursery ground properties

12 pages, 11 figures, 6 tablesNutritional condition of anchovy Engraulis anchoita larvae from Northern Argentinean sea was assessed and compared in three areas characterized by dissimilar oceanographic features (estuarine, mixed and shelf waters). Morphometrical, histological and biochemical (RNA/DNA) indexes were used and larvae were compared through different developmental stages. Multivariate analyses performed on normalized morphometric variables showed that larvae from mixed waters where characterized by higher body depths; variables that indicate a better nutritional condition. Mean histological condition index obtained for larvae at intermediate developmental stages was significantly lower in estuarine waters than those estimated with samples from mixed or shelf waters. Anchovy larvae from the mixed water area showed a higher slope in the log RNA versus log DNA relationship than larvae from the other areas, which indicates that the former were in better condition. Also, standardized RNA/DNA index (RNA/DNAs) resulted slightly better in mixed waters than in shelf area, for larvae at intermediate developmental stages, but due to the high variability of RNA/DNA ratio, no significant differences were found between areas. Finally, using literature equations relating RNA/DNAs, temperature and growth, growth rate and growth performance were estimated. Mean growth performance did not differ between areas and was temperature independent. In conclusion, larval condition was relatively high at all stations, but our results suggested that it was slightly better in frontal areas characterized by water masses with intermediate salinities. We also provide evidence that anchovy larvae might not be food limited in any of the studied areas.This work was supported by the INIDEP and the CONICET. M.V. Diaz acknowledges MAEC-AECI Fellowship support that allowed transportation to Barcelona in order to analyse RNA/DNA contents. This is INIDEP contribution no. 1638.Peer reviewe