Los peces y las algas de los bosques submarinos del noreste Atlántico

En las grietas vivían las boquiabiertas rabosas de gruesos labios, que con expresión de  negroide insolencia te contemplaban agitando las aletas. En la penumbra de las
algas se arracimaban los erizos de mar como relucientes y marrones castañas de Indias, virando levemente sus espinas hacia el posible peligro a manera de brújulas. A
su alrededor se adherían a las rocas las anémonas, rollizas y lustrosas, moviendo los brazos con aire de danza lánguida y oriental por atrapar las quisquillas traslúcidas
que pasaban velozmente.

Gerald Durrell
Mi familia y otros animales

Usé este texto del genial Gerald Durrel en Mi familia y otros animales (1956), como prólogo al capítulo de mi tesis doctoral que ahora por fin se publica en Marine and Freshwater Research. En el artículo, analizamos las variaciones espaciales y temporales, y su relación con el hábitat, de las comunidades de peces de los bosques de algas de Galicia.

Representación del paisaje subacuático basado en los diferentes resultados del estudio mostrando los principales ambientes de los arrecifes rocosos costeros, incluyendo las especies de algas y de peces más representativas: (a) ambientes rocosos verticales, (b) ambientes rocosos horizontales y (c) ambientes arenosos. 1, Laminaria hyperborea; 2, Saccorhiza polyschides; 3, Desmarestia aculeata; 4, Halidrys siliquosa; 5, Laminaria ochroleuca; 6, Saccharina latissima; 7, Cystoseira baccata; 8, Sargassum muticum; 9, Diplodus sargus; 10, Labrus bergylta (pinto en la parte superior y maragota a continuación); 11, Labrus mixtus (macho en la parte superior y hembra en la parte inferior); 12, Serranus cabrilla; 13, Trisopterus luscus; 14, Boops boops; 15, Diplodus vulgaris; 16, Spondyliosoma cantharus; 17, Pollachius pollachius; 18, Mullus surmuletus.

 

 

 

La pesca marítima recreativa en Europa

Acaba de publicarse nuestro artículo sobre la pesca marítima recreativa en Europa. La revista es Fish and Fisheries y es de acceso gratuito:

Recreational sea fishing in Europe in a global context—Participation rates, fishing effort, expenditure, and implications for monitoring and assessment

Abstract

Marine recreational fishing (MRF) is a high-participation activity with large economic value and social benefits globally, and it impacts on some fish stocks. Although reporting MRF catches is a European Union legislative requirement, estimates are only available for some countries. Here, data on numbers of fishers, participation rates, days fished, expenditures, and catches of two widely targeted species were synthesized to provide European estimates of MRF and placed in the global context. Uncertainty assessment was not possible due to incomplete knowledge of error distributions; instead, a semi-quantitative bias assessment was made. There were an estimated 8.7 million European recreational sea fishers corresponding to a participation rate of 1.6%. An estimated 77.6 million days were fished, and expenditure was €5.9 billion annually. There were higher participation, numbers of fishers, days fished and expenditure in the Atlantic than the Mediterranean, but the Mediterranean estimates were generally less robust. Comparisons with other regions showed that European MRF participation rates and expenditure were in the mid-range, with higher participation in Oceania and the United States, higher expenditure in the United States, and lower participation and expenditure in South America and Africa. For both northern European sea bass (Dicentrarchus labrax, Moronidae) and western Baltic cod (Gadus morhua, Gadidae) stocks, MRF represented 27% of the total removals. This study highlights the importance of MRF and the need for bespoke, regular and statistically sound data collection to underpin European fisheries management. Solutions are proposed for future MRF data collection in Europe and other regions to support sustainable fisheries management.

Contando peces con ROV, RUV y SCUBA

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