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Ship causalities – reasons and statistical analyze

Denev Y.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

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2022

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Vol. 16 No. 4

607--610

EN

The paper deals with most recently damages caused ship accidents and their number in the World Ocean. A lot of them are a result of bad technical condition or human mistake. The first reason is due to ship age, non- qualitative maintenance and non- qualitative repair of ship hull thought its life cycle, while the second reason is mainly of labour safety neglect. Analyzed period covers 27 years, from 1994 up to 2021. The analyze is done for two ships group- merchant and special ships. The paper described damages on ship hull and its structural members caused ship accidents and environmental pollution in relation with age of ships. The number and degree of marine causalities are analyzed. Moreover, statistical analysis presents the often causalities and areas in the World Ocean by ship and damage types. Finally, probabilistic density distributions of damages were shown by Fisher distribution curve. The damages on Fisher distribution curve are presented independent one another.

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Could submarine groundwater discharge be a significant carbon source to the southern Baltic Sea?

Szymczycha B., Maciejewska A., Winogradow A., Pempkowiak J.

Oceanologia

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2014

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No. 56 (2)

327--347

EN

Submarine Groundwater Discharge (SGD) is an important yet poorly recognised pathway of material transport to the marine environment. This work reports on the results of dissolved inorganic carbon (DIC) and dissolved organic carbon (DOC) concentrations and loads in the groundwater seeping into the southern Baltic Sea. Most of the research was carried out in the Bay of Puck (2009-2010), while in 2013 the study was extended to include several other groundwater seepage impacted areas situated along the Polish coastline. The annual average concentrations of DIC and DOC in the groundwater were equal to 64.5 ± 10.0 mg C L-1 and 5.8 ± 0.9 mg C L-1 respectively. The carbon specific flux into the Bay of Puck was estimated at 850 mg m-2 yr-1. The loads of carbon via SGD were scaled up for the Baltic Sea sub-basins and the entire Baltic Sea. The DIC and DOC fluxes via SGD to the Baltic Sea were estimated at 283.6 ± 66.7 kt yr-1 and 25.5 ± 4.2 kt yr-1. The SGD derived carbon load to the Baltic Sea is an important component of the carbon budget, which gives the sea a firmly heterotrophic status.

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Modelled quantum yields and energy efficiency of fluorescence, photosynthesis and heat production by phytoplankton in the World Ocean

Ostrowska M., Woźniak B., Dera J.

Oceanologia

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2012

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No. 54 (4)

565-610

EN

The paper discusses the utilization budgets of the excitation energy of phytoplankton pigment molecules activated on absorbing solar radiation under various typical conditions obtaining in the World Ocean. The deactivation of these molecules following the conversion of the excitation energy to the fluorescence of chlorophyll a, the photosynthesis of organic matter and heat is taken into account. To this end, a great many model computations were performed; these made use of the authors' earlier models of the dependence of the quantum yields and energy efficiencies of the above processes on the three principal environmental factors governing the functioning of marine plant communities: the chlorophyll a concentration in the surface water layer (the trophic index of waters), temperature and the underwater irradiance at different depths in the sea. These model relationships were used to determine vertical profiles of the quantum yields and energy efficiencies of the chlorophyll a fluorescence, photosynthesis and heat production by phytoplankton in different trophic types of sea in three different climatic zones (tropical, temperate and polar), in two seasons of the year - June (summer in the northern hemisphere) and January (winter in the northern hemisphere). The results of the calculations are given for areas of oceanic Case 1 waters, which cover more than 90% of the volume of all basins in the World Ocean (according to the optical classification by Morel & Prieur 1977). The results of these calculations, though preliminary, provide a comprehensive description of the range of variability of the yields / efficiencies of the three deactivation processes. The results have made it possible to summarize, within the context of the euphotic zone, of the budgets of phytoplankton pigment molecule excitation energy expended on three complementary processes, namely, the fluorescence of chlorophyll a, the photochemical assimilation of inorganic carbon and the photosynthesis of organic matter, and the radiationless, nonphotochemical conversion of the pigment molecules' activation energy to heat.