An Individual-based Probabilistic Model for Fish Stock Simulation

We define an individual-based probabilistic model of a sole (Solea solea) behaviour. The individual model is given in terms of an Extended Probabilistic Discrete Timed Automaton (EPDTA), a new formalism that is introduced in the paper and that is shown to be interpretable as a Markov decision process. A given EPDTA model can be probabilistically model-checked by giving a suitable translation into syntax accepted by existing model-checkers. In order to simulate the dynamics of a given population of soles in different environmental scenarios, an agent-based simulation environment is defined in which each agent implements the behaviour of the given EPDTA model. By varying the probabilities and the characteristic functions embedded in the EPDTA model it is possible to represent different scenarios and to tune the model itself by comparing the results of the simulations with real data about the sole stock in the North Adriatic sea, available from the recent project SoleMon. The simulator is presented and made available for its adaptation to other species.Comment: In Proceedings AMCA-POP 2010, arXiv:1008.314

Variability of nutrient and thermal structure in surface waters between New Zealand and Antarctica, October 2004-January 2005

We describe the upper ocean thermal structure and surface nutrient concentrations between New Zealand and Antarctica along five transects that cross the Subantarctic Front, the Polar Front (PF) and the southern Antarctic Circumpolar Current (ACC) front. The surface water thermal structure is coupled with variations in surface nutrient concentrations, making water masses identifiable by both temperature and nutrient ranges. In particular, a strong latitudinal gradient in orthosilicate concentration is centred at the PF. On the earlier sections that extend south-west from the Campbell Plateau, orthosilicate increases sharply southward from 10–15 to 50–55 µmol l−1 between 58° S and 60° S, while surface temperature drops from 7°C to 2°C. Nitrate increases more regularly toward the south, with concentrations ranging from 10–12 µmol l−1 at 54° S to 25–30 µmol l−1 at 66° S. The same features are observed during the later transects between New Zealand and the Ross Sea, but the sharp silica and surface temperature gradients are shifted between 60° S and 64° S. Both temporal and spatial factors may influence the observed variability. The January transect suggests an uptake of silica, orthophosphate and nitrate between 63° S and 70° S over the intervening month, with an average depletion near 37%, 44% and 29%, respectively. An N/P (nitrite + nitrate/orthophosphate) apparent drawdown ratio of 8.8±4.1 and an Si/N (silicic acid/nitrite + nitrate) apparent drawdown ratio >1 suggest this depletion results from a seasonal diatom bloom. A southward movement of the oceanic fronts between New Zealand and the Ross Sea relative to prior measurements is consistent with reports of recent warming and changes in the ACC

Prostorna raspodjela fizikalnih, kemijskih i bioloških oceanografskih karakteristika, fitoplanktona, hranjivih tvari i otopljene obojane organske materije (CDOM) u Bokokotorskom zaljevu na Jadranu

The temporal variations of temperature, salinity, fluorescence, dissolved oxygen concentration, Coloured Dissolved Organic Matter (CDOM) and of chemical (nutrients, chlorophyll a) and biological (phytoplankton composition) parameters in the Boka Kotorska Bay were observed during two periods. CDOM regulates the penetration of UV light into the sea and therefore plays an important role in many hydrological and biogeochemical processes in the sea surface layer including primary productivity. In the framework ADRICOSM-STAR it was possible to investigate the Boka Kotorska Bay during May and June 2008 in order to increase an understanding of optical and chemical characteristics and their evolution during these periods. In both periods station KO (located furthest from the open sea) presented different physical, chemical and biological characteristics with respect to the other stations inside the Boka Kotorska Bay. A positive correlation was found between CDOM and chlorophyll a (R = 0.7, P < 0.001, n = 15) and this implies that in this area, similarly to the open sea, the primary source of CDOM should be the biological production from phytoplankton. This is probably due to the fact that the rivers entering the Boka Kotorska Bay are not severely impacted by man.U Bokokotorskom zaljevu su mjerene vremenske promjene temperature, saliniteta, fluorescencije, koncentracije otopljenog kisika, obojene otopljene organske materije (CDOM) i kemijskih (hranjive soli, klorofila) i bioloških (sastav fitoplanktona) parametara tijekom dva razdoblja (svibanj i lipanj 2008. godine). CDOM određuje prodiranje UV svjetlosnih zraka u more i stoga igra vrlo važnu ulogu u mnogim hidrološkim i biogeokemijskim procesima u površinskom sloju mora koji uključuje primarnu produkciju. Unutar ADRICOSM-STAR projekta, bilo je moguće istražiti Bokokotorski zaljev tijekom svibnja i lipnja 2008. godine radi povećanja razumijevanja optičkih i kemijskih karakteristika i njihovog razvoja kroz ova razdoblja. Zbog dotoka krških rijeka i smanjenja razmjene s otvorenim morem, u oba razdoblja postaja KO (smještena najdalje od otvorenog mora) je pokazala različite fizikalne, kemijske i biolo{ke karakteristike u odnosu na postaje unutar Bokokotorskog zaljeva. Pronađena je pozitivna korelacija izme|u CDOM i klorofila a (R = 0.7, P < 0.001, n = 15) {to upućuje na to da bi u ovom području, slično otvorenom moru, primarni izvor CDOM trebao biti biološka produkcija od fitoplanktona. To je vjerojatno zbog toga što dotoci rijeka u Bokokotorskom zaljevu nisu ozbiljnije ugroženi ljudskim djelovanjem

Water temperature from XBT taken from the research vessel Italica in the Southern Ocean and Southwest Pacific Ocean from 2000-01-07 to 2000-02-18 (NCEI Accession 0173212)

Vertical temperature profiles were taken from January 7th 2000 to February 18th 2000 from the research vessel Italica during an oceanographic cruise between New Zealand and the Ross Sea in the framework of the Climatic Long Term Interaction for the Mass-balance in Antarctica (CLIMA) project of the Italian National Antarctic Research Programme (PNRA) using Sippican T7 Expendable Bathythermograph (XBT). Used probes have a vertical resolution of 65 cm and a maximum nominal depth of 760 m. XBT launches have been interrupted in case of severe sea and weather conditions. This implies the presence of gaps in the sampling. The spatial resolution of the sampling varies between 20 nm and 40 nm according to the specific cruise leg. All temperature profiles are quality controlled for consistency between adjacent profiles and through spike editing. Data are provided in TXT format

Water temperature from XBT taken from the research vessel Italica in the Southern Ocean and Southwest Pacific Ocean from 1999-01-05 to 1999-01-11 (NCEI Accession 0173211)

Vertical temperature profiles were taken from January 5th 1999 to January 11th 1999 from the research vessel Italica during an oceanographic cruise between New Zealand and the Ross Sea in the framework of the Climatic Long Term Interaction for the Mass-balance in Antarctica (CLIMA) project of the Italian National Antarctic Research Programme (PNRA) using Sippican T7 Expendable Bathythermograph (XBT). Used probes have a vertical resolution of 65 cm and a maximum nominal depth of 760 m. XBT launches have been seldom interrupted in case of severe sea and weather conditions. This implies the presence of gaps in the sampling. Final mean spatial resolution of the sampling is 15 nm. All temperature profiles are quality controlled for consistency between adjacent profiles and through spike editing. Data are provided in TXT format