Techniques to study vision: spectroradiometry and microspectrophotometry

Spectroradiometry is used to measure light (intensity and quality), in the air and underwater. We use a high-resolution portable scanning spectroradiometer to measure the light field in natural environments, sea pens, indoor aquaculture systems, and experimental settings. The instrument can also be used to measure spectral transmission through materials and/or organisms, and reflectance off surfaces. In this way, we determine what intensity and quality of light to mimic in experiments and in rearing environments.

Microspectrophotometry (MSP) is a refinement of spectrophotometry. A finely-focussed beam of light is directed through the outer segment of photoreceptor cells (the cells upon which vision is based) and absorption profiles of the photopigments contained therein are generated. In this way, we can ask marine organisms what colours of light they can see. This information allows us to match the light environment in a rearing system to the characteristics of the organism’s visual system, and to make appropriate adjustments as they grow.