Phytoplankton cell size structure strongly determines food webs, carbon pathways and energy flows, consequently moderating ecosystem functioning (Legendre & rASSouLzAdegAn, 1995; MArAÑón, 2009). It is generally accepted that in conditions when nutrients are sufficiently This work describes the dynamics of the autotrophic plankton community in Lim Bay in the north-eastern part of the Adriatic Se...

Understanding of the processes affecting recruitment of commercially important fish species is one of the major challenges in fisheries science. Towards this aim, we investigated the relation between North Sea hydrography (temperature and salinity) and fish stock variables (recruitment, spawning stock biomass and pre-recruitment survival index) for 9 commercially important fishes using spatiall...

This paper estimates the economic value of the North Sea cod (Gadus morhua) stock under recent catch and several recovery scenarios. The research presents results on: a) what the value of catches and biomass would have been if the EU fishing fleet had followed the International Council for the Exploration of the Sea scientific recommendations (SRs) and Total Allowable Catches (TACs) in the 1986...

Weights of edges and nodes on food webs which are available from the empirical data hide much information about energy flows and biomass distributions in ecosystem. We define a set of variables related to weights for each species i, including the throughflow Ti, the total biomass Xi, and the dissipated flow Di (output to the environment) to uncover the following common patterns in 19 empirical ...

We analyze multi-period harvest problems for a renewable resource under biological uncertainty when harvesting is size-dependant. First, we show that the decision to harvest can be modeled as a real option and we derive analytical expressions for the value of the resource stock and the mean time between harvests, with and without uncertainty. We then illustrate numerically how uncertainty affec...

Fisheries research on the green sea urchin in Maine has been limited despite its importance to the state's fishing industry. The objective of this thesis was to generate critical information for the management and monitoring of the Maine green sea urchin fishery. In particular there are three main areas of interest: (1) an investigation of biological reference points; (2) spatial analysis and b...

Biological carbon sequestration by forest ecosystems plays an important role in the net balance of greenhouse gases, acting as a carbon sink for anthropogenic CO2 emissions. Nevertheless, relatively little is known about the abiotic environmental factors (including climate) that control carbon storage in temperate and boreal forests and consequently, about their potential response to climate ch...

This experiment was laid out in order to evaluate the effects  of different biofertilizers on yield components of barley. The experiment was a factorial design with three replications. Treatments were three nitrogen biofrtilizers (Nitroksin, Nitrokara and Supernitroplass) and three phosphate  biofrtilizers (Phosphate barvar2, Biozarr and Superplass) with control for them and yield components we...

The northern tuna stocks in the Pacific have specific characteristics: long-term large variability of the total biomass, sparse stock-recruitment relationship, and no obvious indication of recruitment overfishing even though the spawning stock biomass sometime fell into in a very low level. In contrast, southern stocks in the Pacific have one way decreasing trends in shorter exploitation histor...