Changes to the Marine Environment

While fishing is the major threat to sharks species in Atlantic Canada and the cause for marine species declines worldwide, this is followed closely by habitat loss and degradation. Destructive fishing procedures, pollution and ongoing coastal developments can have serious impacts on marine habitats. The disturbance of critical habitats (e.g. areas for spawning, mating, etc.) that species depend on are seen as primary concerns. As a result of their life history characteristics, sharks are often unable to adapt to rapidly changing environmental conditions. Sharks depend heavily on properly functioning ecosystems in order to sustain growth, reproduction and survival. The documentation of how habitat loss will affect the health, distribution and productivity of sharks remains scarce, however; it is assumed that on-going degradation will likely impact shark populations and their recovery.

Until recently, the location of the critical habitats for sharks remained largely unknown. However, with the use of new technology, such as archival satellite popup tags, scientists are now able to identify areas of importance including migratory pathways and other critical habitats.

Climate change and its impacts on the marine ecosystem is also becoming a cause of concern for sharks, particularly in terms of how population distributions and habitats for sharks, as well as their prey, will be affected. For some species of shark it is possible that ocean warming may result in a change of geographic distributions, potentially becoming smaller as species are forced to move northward or into deeper waters. For Atlantic Canada, we may already be seeing a change in the species of sharks occurring in our waters.