Movement of yellowtail snapper (Ocyurus chrysurus Block 1790) and black grouper (Mycteroperca bonaci Poey 1860) in the northern Florida Keys National Marine Sanctuary as determined by acoustic telemetry

We tagged a total of 14 yellowtail snapper (Ocyurus chrysurus Bloch 1790) and black grouper (Mycteroperca bonaci Poey 1860) inside the Conch Reef Research Only Area (a no-take marine reserve) in the northern Florida Keys National Marine Sanctuary in November 2001. Both species are heavily exploited in the region. Our objective was to characterize site fidelity and movement behavior along the reef tract to the north and south of the release point. Fishes were collected by baited hook and line from the surface, surgically-tagged with coded-acoustic transmitters, and returned to the reef by snorkelers. Tracking of fish movement behavior was conducted by five acoustic receivers deployed on the seafloor from Davis Reef in the south to Pickles Reef in the north. Fishes were tracked for up to eight months. Results indicated that the majority of signal detections for individual fish from both species were recorded at the two Conch Reef receivers. Limited movement from Conch Reef to Davis Reef was recorded, but no signal detections were recorded at the two sites to the north of Conch Reef. These results suggest that both species show site fidelity to Conch Reef. Future studies will seek to characterize this site fidelity with increased temporal and spatial resolution at Conch Reef. (PDF contains 25 pages.

Tracking Pacific bluefin tuna (Thunnus thynnus orientalis) in the northeastern Pacific with an automated algorithm that estimates latitude by matching sea-surface-temperature data from satellites with temperature data from tags on fish

Data recovered from 11 popup satellite archival tags and 3 surgically implanted archival tags were used to analyze the movement patterns of juvenile northern bluefin tuna (Thunnus thynnus orientalis) in the eastern Pacific. The light sensors on archival and pop-up satellite transmitting archival tags (PSATs) provide data on the time of sunrise and sunset, allowing the calculation of an approximate geographic position of the animal. Light-based estimates of longitude are relatively robust but latitude estimates are prone to large degrees of error, particularly near the times of the equinoxes and when the tag is at low latitudes. Estimating latitude remains a problem for researchers using light-based geolocation algorithms and it has been suggested that sea surface temperature data from satellites may be a useful tool for refining latitude estimates. Tag data from bluefin tuna were subjected to a newly developed algorithm, called “PSAT Tracker,” which automatically matches sea surface temperature data from the tags with sea surface temperatures recorded by satellites. The results of this algorithm compared favorably to the estimates of latitude calculated with the lightbased algorithms and allowed for estimation of fish positions during times of the year when the lightbased algorithms failed. Three near one-year tracks produced by PSAT tracker showed that the fish range from the California−Oregon border to southern Baja California, Mexico, and that the majority of time is spent off the coast of central Baja Mexico. A seasonal movement pattern was evident; the fish spend winter and spring off central Baja California, and summer through fall is spent moving northward to Oregon and returning to Baja California

“Basically theory-driven”?: A critical analysis of the democracy barometer

Das Demokratiebarometer ist einer der neusten Ansätze, um die Qualitätsunterschiede zwischen etablierten Demokratien vergleichend messbar zu machen. Neben positiven Aspekten, wie der Sensibilität was de jure und de facto Indikatoren für Demokratie anbelangt oder der gründlichen Dokumentation von Methodik und verwendeten Daten, zeigen wir in unserer kritischen Diskussion dieses Ansatzes, dass auf den Ebenen der Konzeptualisierung, der Operationalisierung und Messung sowie der Aggregation weiterhin Probleme vorliegen. So geht erstens das Spannungsverhältnis der drei grundlegenden Demokratieprinzipien Freiheit, Gleichheit und Kontrolle im Laufe der Indexbildung verloren, zweitens wird die schrittweise Ausdifferenzierung des Konzeptbaums nicht bis auf die untersten Ebenen sauber durchgeführt, wodurch es zu Fehlanpassungen zwischen Konzept und Operationalisierung kommt, und drittens führt die verwendete Skalierung und Aggregationsregel zu unerwünschten Nebenwirkungen. Auch können die von den Autoren des Demokratiebarometers selbst durchgeführten Validierungsversuche bei genauerer Betrachtung nur bedingt überzeugen.The Democracy Barometer is a newly established approach towards measuring differences in the democratic quality of widely recognized democracies. Apart from positive aspects like its sensitivity for de jure and de facto indicators of democracy and its thorough documentation, the critical examination reveals problems in terms of conceptualization, operationalization and measurement as well as aggregation of the data. First, the theoretically meaningful tension between the three basic democratic principles of freedom, equality and control vanishes in the course of the index construction. Second, the step-by-step development of the concept tree from its stem towards its leaves remains unclear to some extent, making it prone to possible mismatches between concept and operationalization. Third, the used scaling method and aggregation rule result in unintended side effects. Finally, on close inspection, the attempts of the Democracy Barometer' authors at validating their approach is not entirely convincing