Survivors
of vessel collisions
Buoyancy
is very important for aquatic animals as the ocean environment
changes substantially with depth. To remain at a preferred
depth with minimal energy expenditure, sea turtles use
pulmonary gas exchange to selectively move lung gas to
the front, back, right or left of the lungs to compensate
for changes in body weight. Many sea turtles that experience
severe trauma, such as boat collision, have buoyancy control
issues from their injuries. This means that lead weights
and similar devices are required for sea turtle survivors
that can no longer control their buoyancy and just ‘bob
like a cork’ on the top of the water.
Ways
to reduce the threat of boats to sea turtles
1.
Vessel strike avoidance for sea turtles
In order to avoid causing injury or death to sea turtles,
ship captains and crew should maintain vigilant watch
during navigation and slow down and/or stop their vessel
to avoid striking. When sea turtles are sighted, they
should attempt to maintain a distance of 45 metres or
greater whenever possible.
2.
Injured or Dead sea turtle Reporting
Vessel crew should report sightings of any injured or
dead sea turtle (or protected species in general), regardless
of whether the injury or death is caused by the vessel.
Report includes date/location of the strike, name of the
vessel involved and species identification.
3.
Zoning and speed limits for significant sea turtle nesting/foraging
areas
Tiered application of zoning and speed limits for coastal
waters is essential in protecting sea turtles in key stages
of their reproduction cycle.
For example the National Marine Park of Zakynthos in Greece
has:
Zone A: No boating activity or fishing of any kind
Zone B: Boats are allowed with speed limits of 6 miles/hour.
Anchoring prohibited.
Zone C: Boats are allowed with speed limit of 6 miles/hour.
Anchoring permitted.
