Threats and protection of seabirds

Threats and risk factors

Various factors in the life history of seabirds make them particularly vulnerable to the effects of human activities in the marine environment. For example:

• many species have high adult survival, but low reproductive output and slow population growth
• most species live for a long time but many do not start breeding until they are several years old
• they usually produce a small number of eggs, or only a single egg per year, and do not always breed every year

Due to these factors, the deaths of breeding adults can have a substantial impact on populations over time.

Some of the threats and risks that can result in death to seabirds and potentially affect their populations are described below.

Interactions with fisheries

The unintentional catch (bycatch) of seabirds from fisheries is an issue affecting thousands of seabirds each year in Canada.

Seabirds are particularly vulnerable to longline, gillnet and trawl fisheries’ activities:

• they may become entangled in trawl or gill nets or they may become hooked and pulled underwater when they attempt to take bait from longlines
  • Albatrosses and large gulls are most frequently caught on longline gear
  • Murres and Rhinoceros Auklets are most frequently caught in salmon gillnets
• they may collide with the cables that run between a vessel and its trawl nets

A combination of factors contribute to the vulnerability of seabirds to injury or death from bycatch:

• many seabirds congregate in marine areas of high productivity, where there is more food
• fisheries also tend to concentrate their activities in high-productivity areas, as target fish are often found there
• given the higher densities of seabirds and fisheries in these areas, there is an increased chance for birds to have fatal interactions with fishing gear
• seabirds might be attracted to fishing vessels as potential sources of food

Presence of debris in the marine environment

• Seabirds may become entangled in plastics and other non-biodegradable items, and they can also confuse them with food
• Ingesting debris can cause blockage of the intestinal tract, reduced appetite, and reduced dietary efficiency
• Debris that are eaten can also lead to the accumulation of contaminants in the birds’ tissues

Contact with oil

• Feathers provide seabirds with waterproofing, insulation and buoyancy, all of which are necessary for survival
• If a seabird comes in contact with even trace amounts of oil, the waterproofing properties of the feathers will be destroyed
• This can lead to death from hypothermia or drowning
• Oiled seabirds that do not die from hypothermia or drowning may die from ingesting petroleum-based oil when they clean their feathers
• Birds that survive being oiled may have reduced life expectancy and reduced breeding success
• Seabirds can be affected by oil spills whether these are:
  • large, single event
  • small, chronic discharges
• Exposure to fish and vegetable oils can be just as deadly to seabirds as petroleum-based oils as they can also disrupt the waterproofing properties of feathers

Attraction to offshore structures

• Seabirds are attracted to large offshore structures including drilling and production platforms
• The birds are attracted by visual cues from the platforms, such as lighting and flares, and more food near the structures
• Birds may be injured or killed if they:
  • collide with the platforms
  • fly into lights or flares
  • come in contact with the thin, barely visible sheens of oil that can form around the platforms

Other threats to seabirds

• contaminants
• introduced predators on nesting colonies
• climate change
• tourism
• disease
• urban development
• aquaculture

Protecting seabirds and reducing threats

Most seabirds are protected by laws or regulations.

Find out about Canada’s role in reducing the risk of seabird mortality from human activities at sea.

To address the sources of chronic oil pollution, Canada:

• coordinates responses to environmental emergencies
• explores the spatial patterns of background oil pollution
• identifies the human activities that may be causing them
• monitors and collects data on oil pollution using:
  • plane surveys
  • satellite tracking

Related links

• Environmental Emergencies Program
• National Aerial Surveillance Program
• Integrated Satellite Tracking of Pollution Program