Research Document - 2010/026
Ecosystem Status and Trends Report for the Newfoundland and Labrador Shelf
By N.D. Templeman
In 2006, the Canadian Councils of Resource Ministers (CCRM) identified the completion of the Ecosystem Status and Trends Report (ESTR) as an early deliverable under the Biodiversity Outcomes Framework. ESTR will report on the assessment of 25 Canadian ecozones (15 terrestrial, 1 freshwater, and 9 marine). This science-based technical report corresponds to one such marine ecozone, the Newfoundland and Labrador Shelf, and is a compilation of available scientific and technical information on the condition, trends, drivers, and stressors of the ecozone. Reports on marine and other ecozones will be brought forward to Environment Canada for incorporation into the National 2010 ESTR under the Biodiversity Outcomes Framework, and will also aid in measuring Canada’s progress towards the Convention on Biological Diversity’s (CBD) 2010 biodiversity targets.
The abiotic characteristics of the Newfoundland and Labrador Shelf Ecozone (NLSE) have changed notably over the past several decades. Since the above average water temperatures of the 1950s and 1960s, and the below average water temperatures of the mid-1980s to mid-1990s, the ocean continues to experience a significant warming trend – with a notable 61-year high in 2006. Sea ice extent and duration has been below average since mid-1990, with 2006 experiencing the lowest sea ice extent since records began in 1963. The biological components of the NLSE have also changed dramatically over the past 40 to 50 years. Phytoplankton biomass has increased over the available time series (since 1961), coinciding with an increase in the numbers of dinoflagellates in the composition of phytoplankton taxa. Many of the larger warmer water offshore demersal species (including the important commercial ones), which were once dominant, have declined to a small percentage of their historic levels and management efforts, mostly through closed fisheries, have not resulted in significantly increased populations, while the remaining individuals are often smaller at maturity. During the same time as the collapse of many larger warmer water offshore demersal species, quite a number of smaller, colder water nearshore species (e.g., alligator fish, shannies etc.) increased in numbers. In the meantime, bottom dwelling crustaceans have increased dramatically, partially due to changing abiotic conditions in the ocean, and partially due to the decline of their predators, demersal fish. Pelagic species have undergone change also – for example, both capelin and herring are increasing in some areas and declining in others, while their size and phenology are also changing. Finally, the use of the oceans is also changing – resulting in economic diversification and competing needs and interests of the marine environment. There has been a shift in commercially fished key species, from groundfish to shellfish. A significant increase has also been observed in offshore oil exploration, development and production, aquaculture development and production, marine commercial transportation, and marine-based tourism.
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