SST Image Processing for Mesoscale Patterns Identification

Understanding the marine environment dynamics to accordingly design computational predictive tools, represents a factor of paramount relevance to implement suitable policy plans. In this framework, mesoscale marine events are important to study and understand since human related activities, such as commercial fishery, strongly depend on this type of phenomena. Indeed, the dynamics of water masses affect the local habitats due to nutrient and organic substance transport, interfering with the fauna and flora development processes. Mesoscale events can be classified based on the presence of specific hydrodynamics features, such as water filaments, counter-currents or meanders originating from upwelling wind action stress. In this paper, a novel method to study these phenomena is proposed, based on the analysis of Sea Surface Temperature imagery captured by satellite missions (METOP, MODIS Terra/Aqua). Dedicated algorithms are presented, with the goal to detect and identify different observed scenarios based on the extraction and analysis of discriminating quantitative features. Promising results returned by the application of the proposed method to data captured within the maritime region in front of the southwestern Iberian coasts are presented.

Selected facets of the fishing industry (early 1963)

<p>Consumer demand, retail distribution and the export trade are important aspects of the New Zealand Commercial Fishery which are outside the specific boundaries of this enquiry. It is a study in government intervention, price negotiation and supply. In analysing these three facets of the industry it was impossible to ignore the other three so they have been treated incidentally where a discussion of them was necessary to understand the central theme. There is scope for additional research into each of the above topics, perhaps more especially into administrative decision making when non economic objectives are involved and also into the optimum scale of plant given the cost conditions that apply to the industry. However, it is hoped that this essay goes part of the way towards meeting the need for fundamental economic research into an industry which periodically attracts the attention of the public, policy makers and Government. Parliament has set up three committees in the past twenty-six years to examine the industry.</p>

Selected facets of the fishing industry (early 1963)

<p>Consumer demand, retail distribution and the export trade are important aspects of the New Zealand Commercial Fishery which are outside the specific boundaries of this enquiry. It is a study in government intervention, price negotiation and supply. In analysing these three facets of the industry it was impossible to ignore the other three so they have been treated incidentally where a discussion of them was necessary to understand the central theme. There is scope for additional research into each of the above topics, perhaps more especially into administrative decision making when non economic objectives are involved and also into the optimum scale of plant given the cost conditions that apply to the industry. However, it is hoped that this essay goes part of the way towards meeting the need for fundamental economic research into an industry which periodically attracts the attention of the public, policy makers and Government. Parliament has set up three committees in the past twenty-six years to examine the industry.</p>

Seasonal migratory patterns of Pacific cod (Gadus macrocephalus) in the Aleutian Islands

Background Pacific cod (Gadus macrocephalus) is an ecologically important species that supports a valuable commercial fishery throughout Alaska waters. Although its life history includes seasonal movement for spawning and feeding, little is known about its movement ecology. Here, we present results from the first study to use pop-up satellite archival tags (PSATs) to track the within-year movements of Pacific cod to understand their potential seasonal movement patterns within the Aleutian Islands. This study was part of a cooperative research project; tagging was conducted onboard commercial vessels during the winter fishing season while Pacific cod were aggregated to spawn in the central Aleutian Islands. Results Of the 36 PSATs deployed, we were able to obtain movement data from 13 Pacific cod that were at liberty between 60 and 360 days. We determined that three tagged Pacific cod were predated on by marine mammals and three were recaptured by the commercial fishery. Geolocation models were produced for four migrating individuals. Eight Pacific cod moved to a productive foraging ground near Seguam Island located 64 to 344 km from their release site and presumed spawning ground within a few weeks of their release. These movements indicate that some Pacific cod in the Aleutian Islands undergo seasonal migration. Three Pacific cod remained near their release locations (within 50 km) for more than 75 days suggesting the existence of partial migration in the population. Two Pacific cod undertook larger movements (378 and 394 km) during which they swam over deep passes and crossed several management boundaries highlighting the potential connectedness of Pacific cod throughout the Aleutian Islands. Conclusions This study provided important initial insights into the seasonal movement patterns of Pacific cod in the Aleutian Islands. Most tracked Pacific cod (77%) undertook migrations in the middle of March (64–394 km) from their winter spawning areas to summer foraging areas, but a few individuals remained in their capture location suggesting a partial migration strategy. Their ability to cross deep passes that were previously seen as potential barriers to movement has expanded our understanding of population connectivity.