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Manav Sawhney


Manav Sawhney in Shikoku, Japan A cold day in Shikoku, Japan. Lots of aonori culture in the background (photo: Ryan Shea)..

Honours Thesis: 2003

Thesis: Use of Fourier transform infrared (FT IR) diffuse reflectance spectroscopy and Hamming distances to study the phycocolloid chemosystematics of the red algae (Rhodophyta)

Abstract: The use of red algal polysaccharide cell wall structures as taxonomic indicators has been a recurring theme in literature for over 58 years. Traditionally the polymeric phycocolloids of the red algal cell walls have been classified into definite structures (carrageenans and agars) based on the phycocolloids present. However, this method has some obvious shortcomings, such as its inability to assign hybrid structures (carragars), or the appearance of agarocolloids in traditional ‘carrageenophytes’. Thus, there is a need to develop an unbiased method of examining phycocolloid structures without assigning them names.

Fourier transform infrared diffuse reflectance spectroscopy was used to analyze the spectra of a large number of red algal species, belonging to several orders. The spectra for each species resulted in a series of ‘peaks’ corresponding to certain wavenumbers (cm-1), which in term correspond to phycocolloid bonds. On the basis of shared/similar peaks, irrespective of their combinations to describe polymeric units, a series of matrices were developed for each family. These were coded as a 0 and 1, indicating the presence or absence of a peak, respectively. Using the concept of vector addition and Hamming distances, a methodology was formulated for analyzing ordinal and familial level groupings of the present plants. Initial analysis on 173 species, representing 39 families and 12 orders of the Rhodophyta, proved to be promising. Some results corroborated previous studies, while others proved to be informative and raised the need for further chemosystematic studies. This provides the impetus for continuing to develop this method as a contribution to red algal systematics.

Manav Sawhney with a line of kelp Manav Sawhney considers a particularly heavy line of kelps at an IMTA site in the Bay of Fundy, Canada (photo: Thierry Chopin).

M.Sc.: 2003 - 2012

Thesis: Development of kelp (Saccharina latissima) as the extractive inorganic component in an integrated multi-trophic aquaculture system with salmon (Salmo salar) and mussels (Mytilus edulis) in the Bay of Fundy, N.B.

Description: The use of by-products (wastes) from one resource use as inputs into another is an age-old, common sense recycling and farming practice. This adage led to the development of a sustainable integrated multi-trophic aquaculture (IMTA) system requiring the combination of fed aquaculture (fish) with extractive inorganic aquaculture (seaweed) and extractive organic aquaculture (shellfish). This project involves the development of kelp (Saccharina latissima) as the extractive inorganic component in an IMTA system at an industrial pilot scale in co-cultivation with salmon (Salmo salar) and blue mussel (Mytilus edulis). Kelp culture techniques were improved with experiments on spore density, further refining the grow-out process. Kelp growth occurs most favourably at medium spore density seedings.

Nitrogen and phosphorus concentrations in seawater and kelp tissues, as well as biomass, at three different aquaculture sites with different exposure regimes (high, medium and low) were monitored to measure the impact of growing kelps in proximity to salmon pens and to evaluate their bioremediation potential, based on site characteristics. Results show that kelps respond more favourably to medium exposure and flow characteristics.

Present occupation: Strategy Yield Analyst for American Airlines