RELEASING MARINE TURTLES CAUGHT IN FISHING NETS AND OTHER DEBRIS

1. INTRODUCTION

One of the primary anthropogenic threats impacting turtle populations worldwide are high levels of accidental capture ('bycatch') in fishing nets, trawls and on long-lines. There are guidelines in place in some geographic regions to encourage fishermen to release live turtles found caught in fishing gear, describing how to bring marine turtles onto boats, release them from netting and remove hooks from their mouths.  However, there are also large amounts of discarded fishing gear (or ‘ghost nets’) floating in the world’s oceans (e.g. from accidental loss, storm damage, equipment failure, deliberate cutting of nets and long-lines, and dumping at sea) and these also trap turtles. Net that has been left in the water for prolonged periods may harbour a variety of marine life including algae, invertebrates, barnacles and fish, attracting turtles to them to forage where they can easily become accidentally entangled. Months or even years after being lost or discarded at sea, these nets continue to catch, injure and often kill marine wildlife. Turtles caught in discarded fishing gear are restricted in movement and unable to dive or feed, suffering starvation, laceration and infection, and eventually suffocation (turtles need to return to the surface to breathe).

2. THE PROBLEM OFF WEST AFRICA

The scale of this problem worldwide is poorly documented.  However, bycatch is considered to be a major threat to existing turtle populations.  Off West Africa, some idea of the size of this problem has been indicated by regular sightings from seismic survey vessels of marine turtles trapped in discarded fishing net.  Most of the turtles involved are olive ridley turtles (endangered species); however, green turtles (endangered species) and leatherback turtles (critically endangered species) have also been observed entangled in fishing gear.  It is not uncommon to see more than one turtle trapped within a single piece of netting, and the animals trapped vary from small immature animals to full-size adults. 

Olive ridley and green turtles trapped in discarded fishing nets, and a young olive ridley turtle caught in plastic debris off Equatorial Guinea

3. HOW CAN SEISMIC VESSELS AND OTHER OFFSHORE PLATFORMS HELP?

Seismic survey vessels and other offshore platforms are in a prime position to make a positive contribution to protecting endangered turtle species.  In recent years with increased environmental awareness onboard seismic survey vessels, sightings of turtles caught in fishing nets have sometimes resulted in the launching of small boats in an attempt to release the animals.  For example, small boats have been launched from seismic survey vessels operating off Congo and Angola to rescue groups of turtles caught in netting and plastic debris.

A seismic crew work from an FRC to release six olive ridley turtles  caught in discarded fishing net off Congo	Seismic crew working from the FRC to free two olive ridley turtles entangled in discarded plastic debris off Angola

Such rescue operations have several obvious benefits, including:

• Conserving endangered species

• Raising environmental awareness and credibility within the offshore geophysical industry

• Removing discarded fishing net from the environment (seismic vessels themselves cut fishing gear and discard it into the environment, and therefore have an obligation to do what they can to counteract this problem), both preventing further marine fauna fatalities and reducing the risk of entanglement with seismic equipment

• Opportunities for small boat training, improving future MOB responses

• Raising crew morale via ‘feel good factor’

However, small boat launches to release trapped turtles are not without some risk to personnel, and it is important to establish protocols to enable potential hazards to be minimised and these operations to be carried out safely.

4. GUIDANCE FOR ESTABLISHING A PROTOCOL FOR CONDUCTING OFFSHORE TURTLE RESCUES

A guidance document has been written with the aim of establishing a generalised protocol for safely conducting offshore turtle rescues using small boats (workboats or fast rescue craft).  While it was developed primarily from experiences onboard seismic survey vessels, the procedures contained here could be adapted and equally applied to any vessel (e.g. standby vessels, chase boats) or platform (e.g. FPSOs, drilling rigs) operating offshore in any warm/tropical region where turtles occur.  It is hoped that seismic contractors and oil & gas companies might adopt this protocol as standard procedure for use onboard their own platforms (weather and operational constraints allowing). 

The guidance document can be downloaded by clicking on the image to the right or on the link below.  The document should be cited as:   Ketos Ecology (2009). Releasing marine turtles caught in fishing nets and other debris: Guidance for establishing a protocol for using small boats launched from offshore geophysical platforms. 9 pp. Download here (1 Mb)

For further information or to provide feedback on turtle rescue attempts, please Contact Us.