Cembella, A. D. Institute of Marine Biosciences - NRC, allan.cembella@nrc.ca
Bauder, A. D. Institute for Marine Biosciences, andrew.bauder@nrc.ca
Lewis, N. I. Institute for Marine Biosciences, nancy.lewis@nrc.ca
Quilliam, M. A. Institute for Marine Biosciences, michael.quilliam@nrc.ca
Lawrence, J. E. Institute for Marine Biosciences, janice.lawrence@nrc.ca
MacIntyre, G. J. Dalhousie University, geoff@predator.ocean.dal.ca
Lewis, M. R. Dalhousie University, marlon.lewis@dal.ca

 
MONITORING HARMFUL ALGAL BLOOMS AT SHELLFISH AQUACULTURE SITES USING IN SITU OPTICAL SENSORS: A CASE STUDY IN COASTAL NOVA SCOTIA
 
Harmful algal blooms are episodic events that may cause faunal mortalities and restrict harvesting of coastal aquaculture resources. Many blooms form cryptic sub-surface aggregations and high biomass is not necessarily a prerequisite for harmful effects. Remote sensing systems (particularly satellite-based) have been of limited application in monitoring these types of blooms. Examples of such blooms from coastal Nova Scotia include those of Alexandrium tamarense, which causes paralytic shellfish poisoning, and A. ostenfeldii, recently associated with spirolide toxicity in bivalve shellfish. Data on standard oceanographic parameters (chlorophyll, macronutrients, plankton composition and abundance, water column stratification) and bulk toxicity of size-fractionated plankton samples from discrete depths were used to establish the spatio-temporal distribution and seasonal occurrence of toxigenic dinoflagellates at two key aquaculture sites. This was complemented with the installation of a moored in situ chain sensor (TACS) that detects both up- and down-welling spectral radiance. The vertical distribution of toxigenic plankton exhibited a temporal shift (from early May to July), which was coupled with the degree of stratification of the water column. Values of the diffuse attenuation coefficient (Kd) were correlated with plankton biomass indicators (chlorophyll and cell numbers), but the chain sensor provided little taxon-specific information on the species assemblage.
 
Day: Friday, Feb. 5
Time: 02:15 - 02:30pm
Location: Eldorado Hotel
 
Code: SS42FR0215E