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Monitoring induction 2016 (Nesting Season)
Transcript of Monitoring induction 2016 (Nesting Season)
During the summer of 1977, two tourists discovered that the loggerhead sea turtle nests on the island of Zákynthos, Greece. Until then, the scientific community was unaware that this species was nesting in Greece.
Archelon collaboration with the NMPZ
In 1981 a monitoring project was initiated on Zákynthos funded by the WWF and in 1983 the Sea Turtle Protection Society of Greece was founded.
ARCHELON's work with sea turtles at the various nesting beaches is important for maintaining and increasing the respective populations and to provide biological data from which we can have better understanding of the turtles' ecology and population status.
ALL our activities that interact with the turtles and nests must be undertaken in a serious, scientific and responsible manner.
Sea turtles in the Mediterranean are protected by several International Conventions to which ARCHELON contributes with the data collected during the summer months.
Convention on the International Trade in Endangered Species of Wild Fauna and Flora (CITES)
All marine turtles are listed in Appendix I of this convention. The species in this appendix are subject to strict trade and transport regulations.
Convention on the Protection of European Wildlife and Natural Habitats (Bern Convention 1979)
are listed in Appendix II of this Convention. The species in this Appendix are to be strictly protected by the Contracting Parties and so are their habitats (especially nesting habitats).
Convention on conservation of Migratory Species of Wild Animals (Bonn Convention, 1979)
Both species of marine turtles (green and loggerhead) are included in Appendix I and Appendix II of this Convention. Parties are bound to strictly protect these species and to endeavour to conclude Agreements for their conservation. The Mediterranean riparian countries that are members of this Convention at present are: Egypt, France, Israel, Italy, Monaco, Morocco, Spain, and Tunisia. The European community is also party to this convention and thus Greece is included.
Convention on the Protection of the Mediterranean Sea Against Pollution (Barcelona Convention, 1976) - Protocol concerning Mediterranean Specially Protected Areas (Geneva, 1982)
Within the Framework of the Barcelona Convention the Specially Protected Areas Protocol is the main instrument dealing with the conservation of wilderness.
Presidential decrees that protect the turtles
Presidential Decree No 617 (Government Gazette 163A/18.7.1980) :
Prohibits the fishing of sea turtles, the destruction of eggs and the collection of hatchlings.
Presidential Decree No 67 (Government Gazette 23A/30.1.1981):
as protected species and prohibits killing, mutilation, trade, capture or export.
Volunteers and shift leaders responsibilities
Morning Surveys and other beach work
Using their four flippers, females will make a body pit in order to test the sand and in case they see that it is suitable for them they will remove the dry sand.
Digging the egg Chamber
Once they have removed all the dry sand, they will start to dig an egg chamber. Using alternate movements of their rear flippers they dig a pitcher shaped hole. The egg chamber has a vase shape (narrow at top and round at the bottom) and can be up to 60cm deep.
This process will take between 10 to 15 minutes
When they have an egg chamber deep enough they lay their eggs into it one or two at a time. The eggs are protected with an antibacterial secretion that covers their surface. While laying, the turtle's eyes secrete a liquid to keep them moist to avoid dry salt and sand.
Covering the chamber
After the female has finished laying her eggs, she covers the egg chamber using her back flippers and the same sand that she had dug.
After the female finishes covering the egg chamber she will camouflage the nest with strong sweeping movements of the front flippers, throwing sand on top and around the egg chamber. Camouflages may be considerably large reaching 2m wide and 5m long.
It will take between 40 minutes and 1 hour from when the turtle is "body pitting" to when she is camouflaging her nest.
ARCHELON T-shirts must be worn during fieldwork to distinguish us as a professional body. All work should be carried out in a professional/scientific manner, thus enhancing the continued growth of ARCHELON's reputation. Care should be taken so that all information recorded is accurate, precise and appropriate.
It is important to start promptly each morning so that all turtle activity can be observed before it has been disturbed by third parties.
Initial assessment of each turtle track is solely based on visual identification.
Identify nesting activity
Map original nest location
Relocate and re-map nest if necessary
Place cage if necessary
Top egg depth (h)
This is the depth (in cm) from the surface of the beach to the top of the uppermost egg in the egg mass.
Bottom of egg chamber (H)
This is the depth (in cm) from the surface of the beach to the bottom of the egg chamber.
Cages are used on beaches where the main threat to nests is human disturbance. They should be placed centrally over the clutch with identifying stones placed at each leg where. Each cage should have the standard ARCHELON nest sign to inform beach users of its purpose.
Nests laid in nesting areas that are not intensively used by tourists should not be caged so that no undue attention is brought to the nest site. Nest-identifying stones should be buried in the sand at predetermined positions relative to the nest (e.g. 1m behind the nest) to facilitate re-identification at a later date.
Nests should only be relocated if they are “doomed”; i.e. they will have little or no chance of survival if left in situ; relocations should only be preformed by trained volunteers.
Severe inundation by the sea, flood drains and rivers etc.
During the regular morning surveys attention should also be given to existing nests. Changes in environmental conditions or human or animal activity (events) during their incubation should be recorded. These events can reduce the hatching success or cause problems for emerging hatchlings.
If nest protection activities are to be carried out then this assessment needs to be physically confirmed by careful digging of the area where the clutch is suspected to be.
Digging should be undertaken for all tracks assessed to be nesting camouflages and for tracks that are suspected to be camouflages (except on Sekania beach).
Besides nests, a turtle may leave evidence of three other behaviors on the beach which are all forms of nesting attempts as they result from activities turtles go through before nesting.
The monitoring equipment is to be looked after properly and is the responsibility of volunteers and shift leaders to make sure that this happens. ARCHELON is not in a financial position to constantly replace misused or lost equipment.
• A body pit is the result of a stationary turtle using all four flippers to dig herself into the beach.
• An abandoned egg chamber is the result of when a turtle starts excavating an egg chamber but then quits the attempt and thus leaves behind evidence of digging an egg chamber.
• A swim is the result of the turtle digging a BP while slowly moving forward.
In a swim individual hind or fore flipper marks are generally not well defined and often there is a pair of parallel ridges running along the sides of the swim where sand has been pushed.
Swims may sometimes be confused with camouflages. A swim may terminate in an AEC or BP or even a nest and these variations should be specifically recorded during morning survey.
When none of these nesting attempts are present and there is only marks of an up track and a down track we say that there is 'no attempt' (NA).
Swims and camouflages can often be mistaken for each other and hence swims should also be physically investigated for presence of eggs.
If no eggs are found then measurements of the suspected nest location should still be recorded
Each adult turtle emergence is recorded in the Morning Survey (MS) book, numbered, and defined as either a nesting or non-nesting emergence.
For non-nesting attempts, GPS coordinates of the highest point of the track should be taken.
Last attempts on non-nesting emergences, or nests themselves, should be GPSd.
In the presence of a nest, measurements should be taken from the point where the nest is located to the beach markers where the nest is laid between, so that its location may be re-determined later in the season. For some beaches, 3 measurements are required.
Measurements should be recorded to accuracy of 10cm and care should be taken to ensure the tape measures are straight, hence giving most accurate measurements.
Nest depths should be recorded when the clutch has been located.
Track diagrams are to be drawn for all nests in the MS book.
Measurements should be recorded accurately and care should be taken to ensure the tape measures are straight, hence giving most accurate measurements.
Track diagrams should be drawn for every nest
The main reason for NS is to tag turtles and their nests, and to assess the health of adult females.
Data obtained from tagging turtles can provide :
nest site fidelity
frequency of injuries
nesting beach philopatry
The team should walk in a close group near to the water’s edge. One member should look carefully at the wet sand region of the beach for tracks, or actual emerging turtles. One other team member should pay attention to further up the beach as sometimes the turtles are seen before their tracks.
No lights should be used at this stage of the patrol.
Once a track is encountered the tagger assesses it and if it is a single ‘up-track’ that means there will be a turtle further up the beach. If the turtle is still on the beach then the team should not make any rapid movements, but instead, sit-down slowly and follow the tagger's instructions.
If there is a turtle on the beach then the tagger crawls up the beach until the turtle is visible and its behaviour and orientation discernible. If the turtle is ‘swimming’, digging the egg chamber or apparently laying, the tagger should carefully approach the turtle to confirm this.
The time at start of each new behaviour performed by the turtle should be recorded from the start of egg laying until it reaches the sea, to accuracy of 1 minute.
When the turtle has almost completed the egg chamber or is encountered laying then the rest of the team can be summoned to the turtle, again, maintaining position behind the turtle.
Contact with the turtle should be kept to an absolute minimum until egg laying has finished.
As soon as the turtle starts to cover the egg chamber and prior to tagging the flippers are checked for any tagging scar. These can be in the form of holes, callouses or cuts. If any is present it is recorded on the NS book. The tagger should never place a tag where tagging scars are present.
Tags are to be applied in the following order:
1st pit tag
2nd metal tag
The scribe always follows the taggers lead
Four measurements are taken from the turtles:
curved carapace length (CL)
straight carapace length (SL)
curved carapace width (CW)
straight carapace width (SW)
These are made to obtain accurate size information on individual turtles that will add to knowledge of both that individual's life history and to trends in average population size over time.
Laganas B beach
Laganas A beach
National Marine Park of Zakynthos
Created in 1999
Protects 135 km2 of land and sea
First Marine Park for the protection of sea turtles in the Mediterranean
1. Collect and record accurate data during the surveys
2. Educate tourists on the beaches when asked for information
3. Look after the equipment
Total nesting area: ~5020m