Percorrer por autor "Reed, John"
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- Comparison of small remotely operated vehicles and diver-operated video of circalittoral benthosPublication . Boavida, Joana; Assis, J.; Reed, John; Serrão, Ester; Gonçalves, Jorge Manuel SantosUnderwater video transect methods using small remotely operated vehicles (ROVs) and diver-operated video (DOV) are commonly used in benthic biodiversity assessments. Constraints posed by deeper waters have made surveys of the circalittoral zone (> 30 m depth), a particularly challenging problem. Here we compare benthic diversity metrics and cluster analyses obtained with ROV and DOV between 45 and 65 m depth off southwest Iberia, across local (tens to hundreds of meters) and regional scales (tens of kilometers). Results showed no difference between methods in terms of the benthic species richness, taxonomic distinctness, and beta diversity, but only minor differences in the spatial structure depicted at the regional level. At the local scale, DOV performed better at discriminating patterns likely because of the divers visual acuity. We found that small ROV and DOV are reliable and comparable methods for the study of circalittoral benthic assemblages and can be used in a complimentary way to detect the greatest amount of variation in benthic ecosystems. Our study facilitates the understanding of capabilities and limitations of two underwater video methods and provides important insight into choice of the most appropriate technique.
- Comparison of small remotely operated vehicles and diver-operated video of circalittoral benthosPublication . Boavida, Joana; Assis, J.; Reed, John; Serrão, Ester; Gonçalves, J. M. S.Underwater video transect methods using small remotely operated vehicles (ROVs) and diveroperated video (DOV) are commonly used in benthic biodiversity assessments. Constraints posed by deeper waters have made surveys of the circalittoral zone ([30 m depth), a particularly challenging problem. Here we compare benthic diversity metrics and cluster analyses obtained with ROV and DOV between 45 and 65 m depth off southwest Iberia, across local (tens to hundreds of meters) and regional scales (tens of kilometers). Results showed no difference between methods in terms of the benthic species richness, taxonomic distinctness, and beta diversity, but only minor differences in the spatial structure depicted at the regional level. At the local scale, DOV performed better at discriminating patterns likely because of the divers visual acuity. We found that small ROV and DOV are reliable and comparable methods for the study of circalittoral benthic assemblages and can be used in a complimentary way to detect the greatest amount of variation in benthic ecosystems. Our study facilitates the understanding of capabilities and limitations of two underwater video methods and provides important insight into choice of the most appropriate technique.
- A well-kept treasure at depth: precious red coral rediscovered in Atlantic deep coral gardens (SW Portugal) after 300 yearsPublication . Boavida, Joana; Paulo, Diogo; Aurelle, Didier; ARNAUD-HAOND, Sophie; Marschal, Christian; Reed, John; Gonçalves, J. M. S.; Serrão, EsterThe highly valuable red coral Corallium rubrum is listed in several Mediterranean Conventions for species protection and management since the 1980s. Yet, the lack of data about its Atlantic distribution has hindered its protection there. This culminated in the recent discovery of poaching activities harvesting tens of kg of coral per day from deep rocky reefs off SW Portugal. Red coral was irregularly exploited in Portugal between the 1200s and 1700s, until the fishery collapsed. Its occurrence has not been reported for the last 300 years.