Measuring Light Attenuation in Shallow Coastal Systems
- *Corresponding Author:
- Ana C. Brito
CO-FCUL, Oceanography Centre
Faculty of Science, University of Lisbon
Campo Grande 1749-016 Lisbon, Portugal
E-mail: [email protected]
Received date: November 23, 2012; Accepted date: January 10, 2013; Published date: January 14, 2013
Citation: Brito AC, Newton A, Fernandes TF, Tett P (2013) Measuring Light Attenuation in Shallow Coastal Systems. J Ecosys Ecograph 3: 122. doi:10.4172/2157-7625.1000122
Copyright: © 2013 Brito AC, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and and source are credited.
Photosynthetic Active Radiation (PAR) was measured using single planar and two-bulb spherical light sensors. The attenuation coefficient (Kd) was found to vary significantly during the year. The highest Kd values were obtained in the station with higher influence of currents and run-off. Our data suggested a reflection of 50% of light that reaches the bottom, which is associated with a decrease in the Kd value obtained with the spherical sensor of 0.15 m-1. This means that flat sensors may underestimate PAR and that spherical sensor may underestimate Kd. This is a critical issue given that knowledge on light attenuation is essential for modeling approaches and quality assessments.