Overview

A comprehensive environmental monitoring¹ program, building on existing monitoring activities, was designed and implemented in 1999 for the northwestern Atlantic² with the aim of increasing the Department of Fisheries and Ocean's (DFO) capacity to understand, describe, and forecast the state of the ocean environment and marine ecosystem and to relate those changes to the predator-prey relationships of marine resources. Environmental monitoring should provide the data sets that are necessary to: (1) track and predict changes in productivity and ocean state; (2) respond to immediate questions posed by clients; (3) alert clients to short- and long-term environmental/ecosystem changes; and (4) provide adequate historical databases to address future issues. For example, environmental monitoring is needed to understand environment-fisheries interactions; to detect trends in climate changes as a basis for rational predictions; to validate oceanographic models; and to provide historical and on-line data for development and exploitation activities in fisheries, oil and gas, and marine transportation.

The main objectives of AZMP are twofold: (1) to collect and analyse biological, chemical, and physical data to characterise and understand the causes of oceanic variability at the seasonal, interannual: and decadal scales; and (2) to provide the multidisciplinary data sets that can be used to establish relationships among the biological, chemical, and physical variability. An additional but no less important objective is to ensure the protection of the marine environment by providing adequate data to support the sound development of ocean activities.

¹ In the present context, zonal or environmental monitoring is defined as the minimal, ongoing collection and analysis of ocean data required to obtain a quantitative description leading to an understanding of the variability of the biological, chemical, and physical characteristics of a particular region.
² AZMP is implemented by DFO’s four Atlantic regions: Newfoundland Region, Gulf Region, Maritimes Region and Quebec Region.

Monitoring Program

The sampling regime (Fig. 1) of AZMP is based on: (1) seasonal and/or opportunistic sampling along eleven sections (with individual stations spaced from 20 to 40 km apart) to obtain information on the variability of the physical environment for the whole northwest Atlantic region; (2) higher frequency temporal sampling (biological, chemical, and physical variables) at six accessible fixed sites to monitor the smaller time scale dynamics in representative areas; and (3) remote sensing of physical (SST) and biological (chlorophyll) variables to provide a broader spatial coverage and to increase our capacity to interpret ocean data (e.g., interpolation or synoptic capacity of site-specific field data), complemented by (4) data coming from other existing monitoring programs (e.g., Continuous Plankton Recorder) and other types of available data (e.g., meteorological data) that have been supplemented with oceanographic observations. In addition to the above, existing regional ecosystem trawl (groundfish) surveys and other ship-of-opportunity cruises acquire data over broad areas of the continental shelf and slope at a minimal increased cost for the monitoring program. Key AZMP variables include

• Biological: The key biological variables are those that describe important changes in ecosystem productivity or shifts in ecosystem structure over time. They include bulk variables (e.g., chlorophyll a, zooplankton biomass) and those that indicate changes in community structure (e.g., species composition).
• Chemical: Key chemical variables measure some important component of the environmental conditions that could or does show variability on seasonal to decadal time scales and has some direct or indirect link to ecosystem. Two chemical variables meet these criteria: nutrients (phosphate, nitrate, and silicate) and oxygen.
• Physical: The key physical variables allow for a quantitative description of the water mass structure in the Atlantic region on seasonal to decadal time scales. The fundamental measurements of temperature and salinity coupled with sea level allow derivation of currents and transport through standard techniques and numerical modeling. Associated variables include ice and freshwater runoff, which primarily affect ocean stratification and salinity, and meteorological variables, which affect current, stratification, and water properties.