APPLYING AN ECOSYSTEM-BASED RISK MANAGEMENT APPROACH TO THE RELATIONSHIP BETWEEN EELGRASS BEDS AND OYSTER AQUACULTURE AT MULTIPLE SPATIAL SCALES IN EASTERN NEW BRUNSWICK, ATLANTIC CANADA.

Abstract

Both eelgrass beds (Zostera marina) and the American Oyster (Crassostrea virginica) are indigenous to Atlantic Canadian coastal waters and are equally recognized as ecological engineers. However, recent eelgrass cover declines and simultaneous increases in the suspended-bag oyster aquaculture (SBOA) industry in coastal eastern New Brunswick (NB) has potentially disrupted various coastal ecosystem services and functions. This research examined the ecological and biophysical relationship between eelgrass cover and local SBOA effects using an ecosystem-based risk management (EBRM) approach at four distinct spatial scales; the near-field, zone of influence, bay, and estuary scales. Using the available literature, regional data, and multi-variate statistical analyses, the relative impact to eelgrass cover at each examined spatial scale was assessed for the risk of ecological, socio-economic, strategic, and operational consequences of the SBOA industry. The results suggest that the eelgrass-SBOA relationship is both positive and negative depending on the scale observed, and that significant trade-offs exist both within and among each spatial scale. This research has provided a preliminary examination of the ecological status and response to SBOA, and has recommended a number of integrated coastal zone management (ICZM) measures, including: 1) using standardized data collection methodologies, 2) integrating stakeholders and their local knowledge into decision-making, 3) implementing best practices, such as the use of less intensive gears and better spacing, and 4) mandating contextualized bay-scale ICZM plans. These recommendations have been offered to ensure the long-term sustainable development of the SBOA industry and the health of local eelgrass ecosystems throughout eastern NB and Atlantic Canada.