Biodiversity of the Glorieuses Marine Park

Tortue verte mission PANAMAG parc marin des Glorieuses

Location: Gorieuses

Conducted in 2015

Mission: PANAMAG1

Expedition Leader : Katia BALLORAIN

This new PANAMAG 1 mission is part of the implementation of the management plan for the Glorieuses Marine Nature Park and will be structured around four components. So, let's board the Antsiva, a new group of scientists composed of 4 teams each with specific goals to achieve.
Team "Turtles" composed of Mayeul, Claire and Katia the team Herbier with Marine and Katia, the team Water Quality with Eric and Clément and finally the team Holoturies composed of Thierry and Alexandra.

Once the equipment and the scientists are installed, the ANTSIVA weighs anchor. At the end of the pass Bandrélé we meet conditions of navigations of damsel, but it is not necessary to drag because a front bringing strong winds coming from the Glorious ones announces itself in the next hours.

Saturday September 26th

15h30n we arrive at Glorious and wet in front of the landing stage. We immediately put the two annexes in the water and Katia, Clément and Nicolas go down to land for a first contact with the policeman and two legionnaires
Marine, the dive manager takes the opportunity to give us a little reminder about the operation of oxygen cylinders and the progress of the dives.
Then, a general briefing is organized at the beginning of the evening. The Kelonia boat will arrive in a week, which disturbs the program a little. Therefore, the 4 teams will have to juggle the two annexes of Antsiva. Negotiations take place in the evening as an aperitif, but with Caipirina helping, solutions are easily found.

Sunday, September 27 - Day 1 of work

25 knots of wind with a formed sea. Even at anchor the boat dances gently in front of the landing stage. Working conditions are not easy, but scientists are hard at work from the very beginning.
The team "Holoturies" composed of Thierry and Alexandra is first deposited on the ground and will realize two stations on the flat. Since illegal sea cucumber fishing is very common in the area, the first objective is to estimate the abundance of commercial species.
Then the Orange Annex goes with two other teams: "Herbarium and Water Quality"
The Herbier team, made up of Marine and Katia, must first and foremost carry out the inventory and cartography of the seagrass beds and define the monitoring stations, this is done through truth observations in the field of diving or towed transects.
The Water Quality team, composed of Clément and Eric will establish an inventory of the general quality of water and sediments.
While Marine realizes points of truth on the seagrass, Eric and Clément take care of the deployment in diving of 3 probes which will follow in a very fine way the T °, the Conductivity and the level of water: 2 probes Temperature / pressure are deployed and another high-frequency multi-parameter probe is wetted on a 3rd site.
In the afternoon, the Water Quality team stays on board and collects sediments since the anchorage of ANTSIVA. To do this a return pulley is struck at the gantry and the handling cable of the bucket is brought to one of the genoa winches. After some tune up the tipper is full of sand of Alimeda of great finesse. (Teaching # 1 plus the sediment sample is fine plus stinks). After the sediment it is necessary to collect a water sample. A 5L niskin is implemented to allow sampling for the different analyzes. In parallel a multiparameter probe is used for the general characteristics (T °, Conductivity, Salinity, dissolved Oxygen, pH).
The Turtles team composed of Mayeul, Claire and Katia must improve knowledge on immature green turtles and in particular their feeding behavior. For this, GOPRO cameras will be fixed on the shell of 10 turtles and record all their movements for 4 hours.
The team returns just before dark, a little peeved. Unfavorable tidal conditions and wind-blown waters did not facilitate their work: they were able to capture only one turtle and the turtle nicknamed "Lilliput" was too small to be equipped with a tag and a GoPro camera.

Monday, September 28 - Day 2 of work

The weather conditions remain the same but the motivation of all is intact. Also, at sunrise the two annexes are already on the water.
For the ground truth, the "herbarium" team uses two observation techniques, a camera immersed one meter above the bottom that will collect the data in depth and the "Manta-Tow". The latter technique is to equip with PMT and transects by being towed, which can cover much larger surfaces.
Then, around 8 o'clock in the morning, the two teams "Holothuries and Herbiers" are deposited on land where the gendarme is waiting for them with the tractor to transport them with their equipment to the east of the island. While Thierry and Alexandra perform two sea cucumber stations on the flat, Eric and Clément collect water and sediment.
Today, the team "Turtle" is hopeful. Three turtles are captured: Black, First and Thalassia. The latter two are equipped with a Gopro camera and a beacon and are released the same day.
Along with the capture of turtles, several Herbarium transects are made during the day.

Tuesday 29 - Day 3 of work

This morning, a humpback whale is seen from the anchorage for the greatest pleasure of all.
Acquisitions continue despite the difficult weather conditions. A slight lull announces itself in the morning that we immediately take advantage to organize the first dives with the team "Holoturies". This works by deploying for each station 3 large transects 100m long and 5m wide, covering an area of 3000 m2 each dive. There is no significant density, so they will have to multiply the stations in order to obtain exploitable results.
The "Turtle" team is moving forward with a single shot, Mushroom will be immediately equipped with its pack "Go Pro + tag"
Every evening, Jérôme Bourjea stayed on land at Ifremer and follows the satellite turtles and gives their positions to facilitate their recapture and consequently to recover the Gopro.
Jérôme is the initiator of this new data collection formula, he was able to test it in March 2015 on Juan de Nova with Stéphane Ciccione (Kelonia). Every night, he encourages the Turtle team by email.

Wednesday, September 30 - Day 4 of work

The whale and its calf are close to the ANTSIVA and evolve in the shallow waters of the flat. We are lucky enough to follow them within 500m of the boat all morning.
Today, the team "Turtle" has a smile: 6 captures and 6 GB Pro installed and deployed the same day. This brings to 9 the number of equipped turtles. Their goal of 10 now seems achievable.

Thursday October 1 - Day 5 of work

Acquisitions are continuing despite the always difficult weather conditions.
The "Holoturies" team, in addition to diving observations, adopts the "manta tow" technique. Thierry and Alexandra were unsure of being able to do Manta Tow on sea cucumbers because of lack of visibility, but this technique is ultimately very effective and requires less means compared to dives. You still need a boat, a pilot, a person in charge of recording observations and transects and an observer in the water. But, thanks to this method, surfaces much larger than those planned will be able to be explored.
The team "Turtle" always surfs on a positive wave, the difficulties of the first days are forgotten. With Panamag, the 10th equipped turtle, the goal is achieved: all Go pro are deployed, it is now to re-capture.
And precisely, with the recapture of the turtle nicknamed "Bourrique", they recover their first Gopro and thus their first filmed data. Bourrique is immediately re-equipped and redeployed.

Friday, October 2 - Day 6 of work

After the Turtles team leaves the catchment area, Antsiva leaves her anchorage for a trip to the lagoon to collect sediments and water samples.
Two diagonals are sampled with a variable success rate for the sediment bin. Indeed, when the bucket falls on a detrital mixed bottom / sand, blocks (even small) of dead reef or pebbles come to block the closing of the bucket, and all the sediment collected is lost during the ascent. The solution would be to carry out a diving dive during the descent to ensure the proper closure of the latter, but the requirements of the professional dive tables being very penalizing, no diver has permission to start water to ensure the success of the tipping course (Teaching No. 2, it would require professional diving tables more suited to the work of scientists). Nevertheless, the data collection continues and the Water Quality team remains very positive about the success of its objectives.
Meanwhile, the two teams Holoturies and Herbiers were able to realize from the orange annex towed transects, a diving station and truths field on the seagrass.
At 17:00, Antsiva returns to the anchorage to find Claire and Mayeul.
The evening Weather report forecasts a good weather for the next 3 days with exceptional conditions the first two days. So we plan for the next day a trip to the island of Lys with the three teams Herbarium, Holoturia and Water Quality.

Saturday October 3rd - Day 7 of work

The arrival of the military boat "La Grandière" is scheduled for the morning. Mayeul and Claire land as they will stay to receive the Kelonia boat. They will stay 2 days on Great Glorious, sharing the life of the camp and participating in unloading maneuvers La Grandière.
Around 8 o'clock, Antsiva arrives at the anchorage of the island of Lys. Two travel catamarans seen the day before are also present. The gendarme takes advantage of the presence of the Grandière to board a zodiac and make contact with the two sailboats. They are asked to leave the area the next morning.
The two teams Herbiers and Holoturie will make transects towed around the island of Lys and two stations in scuba diving.
The Water Quality team collects water and sediment samples and sets up a DGT sampler to study chemical contamination.
Clement (TAAF) has meanwhile, a whole day of work on the islet of the lily. We leave it on the ground where it will pose about thirty rodent traps, delimit the colonies of birds, in particular the brown nodis and the terns and make an inventory of the camps of illicit fishermen.

Sunday, October 4th - Day 8 of work

Second day on the island of Lys. Scientists take advantage of this beautiful weather window to extend their observations by diving and towed transects.
A station is made on the blue hole, also called "the pool". Observations made during previous missions are confirmed: we note the abundance of a species of sea cucumber. The Herbarium team makes visual radials, covering 44 km of ground truth from the orange appendix. During their handling, they also cross a whale and its calf and a group of long-beaked dolphins.
In the afternoon, Antsiva moves to allow the Water Quality team to reach new stations to the west and north that are more exposed to the great East swell. Only the sampling of water is carried out, the sediment samples are impossible to realize because of the presence of too much rocks and meadows.
In the evening, we take news of Claire and Mayeul still on Great Glorious. They recovered their boat and immediately went back to work. With the recapture of the turtles Shark and Panamag, two new Gopro could be recovered. Shark was immediately re-equipped with a Gopro.

Monday, October 5 - Day 9 of work

This morning the wind is blowing again and the night has been particularly hectic. Clement recovers the rodent traps on the islet and we leave the anchorage to join Great Glorious. The swell is up and the boat planned for the observation of the meadows joins us. Waves of nearly 3 meters on the verge of breaking convinced them to turn back. Suddenly the exploration is organized around the anchorage of the landing stage.
Boat trips on ANTSIVA, diving, manta-tow, tipping and sediment sorting. Everyone is satisfied with the data collected.
For the Turtle team, morale is good because a new GoPRo could be recovered.
A big shark is observed in cloudy water, Mayeul thinks of a tiger shark without being able to affirm it.

Tuesday, October 6 - Day 10 of work

This morning, the team "Holoturies" takes advantage of favorable weather conditions and a small tidal coefficient to visit "Les Roches Vertes" and "Glo-3" station located on the external slope, in the East reef. The "Green Rocks" station is rich in large blue / beige starfish (Linckia laevigata) and Glo 3 remains a reference station on the east side for GCRMN monitoring, but relatively poor in abundance of sea cucumbers. Eric and Clément join the rotation to carry out a collection of sediments on the East with the small bucket.
For the team turtle is the euphoria: the goal is now reached with the recapture of 3 new Go PRO.
Today new shark sighting, it is indeed a Tiger, a young about 2.50m that Katia managed to film from the annex. From now on, the observations in Manta-Tow are done with less serenity.
Tonight a barbecue party is organized by the military. At 18:00 everyone arrives, except Eric who has work late and Nico and Said who remain to watch over the ANTSIVA. During the evening, the weather conditions deteriorate, it becomes hazardous to return to the edge of the night and everyone is invited to sleep on the ground. The soldiers make available pico beds in the shelter that creates a large dormitory where everyone can enjoy the snoring of others ...
A little night for some, deep sleep for others.

Wednesday October 7th - Day 11 of work

5:30 am, the whole team is already on the beach, in a hurry to re-embark on board. Only Clement (TAAF) remained at the camp because he planned to accompany the gendarme on his tour of locating turtle nesting tracks.
In the early afternoon, the Turtle team is again facing a Tiger shark and this time it is an imposing individual of 4 meters long. Each boat is warned by VHF and is asked to stop any towing activity. The Manta-Tow is definitely out of date! This is the solution to assess the abundance of sea cucumbers, but a safety problem arises especially when visibility is reduced.

Thursday, October 8 - Day 12 of work

Today, the team "Turtle" will recover his 9th GoPro. The camera took the water but the recorded data are usable. A total of 35 hours of images were recorded and the first screenings promise excellent results.

Friday, October 9 - Day 13 of work

Last day on Glorious. The weather conditions improved a little and Thierry and Alex took the opportunity to do a diving exploration with Clément and Marine.
A total of 24 km of Manta Tow were carried out to evaluate the abundance of commercial sea cucumbers in the Glorieuses, an area of 120 000 m2 and only 223 sea cucumbers could be identified.
For its part, the team Tortue leaves with two boats in search of 3 Gopros still missing. Despite a diligent search they come back empty handed. Of all the turtles equipped, only 2 of them, nicknamed Beirout and Panamag have not been reviewed by the team. The zone presence of tiger sharks and the rather fearful behavior of turtles on Glorious suggest a tragic end for these two.
After lunch, storage operation for departure. The Turtle team drops off its boat at the camp, which will leave for Reunion Island in a next rotation.
16:30, everything is rigged and the two annexes are brought back on board. The ANTSIVA can pair. It is in an uncomfortable swell and with a wind too weak to inflate sufficiently the sails that we head for Mayotte.

Saturday 10th of October

Most of the navigation to Mayotte is by engine and we only have a few good hours to hoist the sails.
Ti photos, viewing videos, work on data collected, reading, rest or card games, everyone organizes his day at his convenience but all are around the square when the bell rings the call of meals ...
This concludes Panamag 1, the first component of knowledge acquisition for sustainable management of the Glorieuses Marine Park. A big thank you to everyone for this new mission.