Archivo de la etiqueta: ROV

¿Quieres contar peces y no sabes cómo?

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En este artículo que acabamos de publicar en Marine and Freshwater Research, comparamos tres métodos para estimar abundancias de peces costeros: mediante buceadores, mediante cámaras de vídeo fijas y mediante ROV.

Además, una foto propia es portada de la revista. La protagonista de la foto, es además la coautora del artículo Diana Fernández-Márquez.

Portada_MFR

Este es el resumen del artículo:

Comparative works on sampling techniques allow selecting the best methods to study each target fish community. We analysed the structure of a coastal fish community in Galicia (north-western Spain) by comparing the following three techniques: diver-based underwater visual census (UVC), remotely operated vehicle (ROV) and remote underwater video (RUV). All techniques detected abundant and frequent taxa, but divers obtained more precise and complete inventories (80% of identified taxa) than did ROV (60%) and RUV (47%), were faster (only 1.4 days to achieve the estimated taxa list) than were ROV (2.0 days) and RUV (475.7 days), and were more reliable in estimating the abundances of highly mobile, less abundant, less frequent, cryptic and smaller fish. Conversely, RUV obtained the poorest estimates of abundances, and even though it obtained more replicates (136), there were more zeros (98%) than with divers (16 replicates, 64% zeros) and ROV (11 replicates, 75% zeros). Furthermore, the economic cost of the video system was triple the cost of the diving gear; consequently, we recommend using divers to study the coastal fish communities in the shallow waters of the North Atlantic Ocean. However, further research is necessary to explore the full capabilities of video techniques in long-term studies, in greater depths and in adverse weather conditions.

Contando peces con ROV, RUV y SCUBA

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La revista Marine and Freshwater Research acaba de aceptar la publicación de un artículo sobre una comparativa de censos mediante buceadores, ROV y cámaras de video remoto (RUV).

 

Short-term performance of three underwater sampling techniques for assessing differences in the absolute abundances and in the inventories of the coastal fish communities of the Northeast Atlantic Ocean
Pablo Pita, Diana Fernández-Márquez y Juan Freire
Abstract
Comparative works on sampling techniques allow selecting the best methods to study each target fish community. We analysed the structure of a coastal fish community in Galicia (NW Spain) comparing three techniques: diver-based underwater visual census (UVC), remotely operated vehicle (ROV) and remote underwater video (RUV). All the techniques detected abundant and frequent taxa, but divers obtained more precise and complete inventories (80% of identified taxa) than ROV (60%) and RUV (47%); fasters (only 1.4 days to achieve the estimated taxa list), compared to ROV (2.0 days) and RUV (475.7 days); and were more reliable to estimate the abundances of highly mobile, less abundant, less frequent, cryptic and smaller fish. Conversely, RUV obtained the poorest estimates of abundances, and though obtained more replicates (136), obtained more zeros (98%), compared with divers (16 replicates, 64% zeros) and ROV (11 replicates, 75% zeros). Furthermore, the economic cost of the video systems tripled the cost of the diving gears, consequently we recommend using divers to study the coastal fish communities in the shallow waters of the North Atlantic Ocean. However, further research is necessary to explore the full capabilities of video techniques in long-term studies, in great depths or in adverse weather conditions.
MF12301  Accepted 02 July 2013

Se presta ROV

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Ayer se manifestaba en la televisión un científico del CSIC denunciando la falta de imágenes del nuevo cráter submarino en la Isla del Hierro. Comentaba que dentro de 100 años se seguirá estudiando esta erupción y se lamentará la falta de información visual acerca de la evolución del fenómeno.

La erupción desde el espacio. Fuente NASA.

En los primeros días de la erupción varios medios de comunicación daban por hecho el envío de un barco de telefónica con un ROV. Numerosas instituciones disponen de estos aparatos (el IEO, Universidades…) y no entiendo la causa de que no se disponga ya de imagen submarina en el área. Si la temperatura o la turbidez son un problema para los ROVs, la hidroacústica también podría ser útil para obtener imágenes casi a tiempo real. Creo que la ciencia española está perdiendo una oportunidad histórica.

En fin, en el Grupo de investigación en Recursos Marinos y Pesquerías de la Universidade da Coruña, disponemos de un pequeño ROV que puede operar y grabar video hasta una profundidad de 150 m.

Cada vez que lo metemos en el agua se estropea el condenado cacharro, pero si alguien lo quiere se lo prestamos… en serio.