PUFFALIS - Journal & logbook

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puffalis

 

03/04/2017

This photo of the team is the perfect concluding remark after two weeks of intense work at sea. The scientists are back in their lab to analyse the samples and data collected and the crew is already preparing the next cruise that starts in a few days.

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Yesterday was the last sampling day with 2 stations. We conducted trawls deeper than 400 m depth in the morning and the evening, looking for a specific hatchetfish, a new species recently described and that had been found nearby the Tombo reef close to the Boulari pass. Indeed we found some hatchetfish but they were small and it will require a close look under the microscope to determine if they belong to the new hatchetfish species.

We finished working around 8pm and steaming toward the Amedée lighthouse to anchor in the lagoon. It was our last night onboard and was a good opportunity to gather all the crew around a nice diner. Moreover it was a special day as it was the captain’s birthday and the cooks had prepared an impressive birthday cake. Later in the night musicians among the scientists and the crew entertained us to the point that we managed a few dances. We all enjoyed this moment and it was a nice way to finish the cruise.

This morning we left the Amédée lighthouse as the sun was rising in the fog and we arrived in Noumea harbour around 9am. This cruise was a great success and the collection of samples has been very satisfying. The hardest work starts now with the analysis of the samples and of the data that will take time

20170402_1The small deep hatchetfish

20170402_2Happy birthday captain !

20170402_3Playing music to entertain us and conclude the cruise

With two sampling stations per day the days are pretty full. However in between two cast of probes, daily life is continuing and yesterday the barber shop was open on the deck. The bosun is very talented and did a few haircuts among the crew.

Last night we had some interesting specimens in the net conducted at night at 35 m depth. Particularly we found beautiful large larvae of lobsters or sleeper lobsters. They are flat and transparent and are particularly well adapted to the pelagic life. Their large size and their transparency likely allow them to avoid predators. However we still find many of them in tuna stomachs. These phyllosoma larvae could inspire nightmares.

This morning we are close to Dumbéa Pass. The sea is particularly calm and being Saturday morning; many small fishing boats are circling around the anchored fish aggregating device (FAD). We also observe shearwaters flying, floating on the water and looking for food.

20170401_1Onboard hairdresser

20170401_2The flat and transparent phyllosoma larva of a lobster or of a sleeper lobster

20170401_3Fish aggregating device (FAD) made of floats, surrounded by small fishing boats

20170401_4Small fishing vessels surrounded by shearwaters

20170401_5Wedge-tailed shearwaters fishing this morning off Dumbea Pass

The islands of the Coral Sea harbour the breeding colonies of several species of "petrels" or Procellariidae. The most abundant “petrel” at this season, on land and at sea, is the wedge-tailed shearwater, whose foraging movements we are currently monitoring.

At sea, we may observe two other emblematic seabirds from New Caledonia. One nests in small colonies in the heights of the chain. This is the New Caledonian petrel, an endemic subspecies of Gould’s petrel. Smaller than the wedge-tailed shearwater, its flight is also faster. It is easy to notice from a distance at sea, when it exposes its ventral part, which is white. The other seabird is the Tahiti petrel, whose breeding colonies are scattered over Grande Terre. Such colonies have been found on the foothills of the Koniambo massif. Mining is a deadly threat to these birds, as prior to accessing the ore, the mining operators remove the first meters of the soil of the forest, where, precisely, Tahiti petrels nest. Tahiti petrels are classified as near-threatened by the World Conservation Union's (IUCN) Red List. The flight of the Tahiti petrel is remarkable: in trade winds, the bird stretches its long tapered wings and effortlessly tacking in and out, following the movement of the swell.

This afternoon, as RV Alis was completing its offshore transect, the attention of the wheelhouse's officers was drawn to the splashes of large marine animals jumping out of the water: was it a pack of tunas hunting? or  marlins breaching? or cetaceans hunting or playing? RV Alis slightly changed its course to approach the area. The tapered tail of a cetacean making a roll-over jump was visible for a second in the binoculars. Then two large black cetaceans, swimming in concert, suddenly appeared: they had an elongated body, a rounded head, a falciform dorsal fin: false killer whales! The two false killer whales rapidly vanished in the reflections of the sun. But soon after, not far from there, another group of smaller cetaceans remained visible, several times breaching: a pod of Risso’s dolphins, which we were able to observe for several minutes.

20170331_1The New Caledonian petrel Pterodroma leucoptera caledonica, a subspecies endemic to New Caledonia

20170331_2Fugitive observation of a Tahiti petrel Pseudobulweria rostrata, a near-threatened species according to the IUCN

20170331_3Wedge-tailed shearwaters Ardenna pacifica foraging for fish off Roche-Percée

20170331_4Risso’s dolphins Grampus griseus by 22°03S 165°29E today at 05:43 UT

At each sampling station an acoustic acquisition device enables us to complement the sampling of zooplankton: this device is the Tracor Acoustic Profiler Sensor (TAPS). The zooplankton net allows stratified sampling at five different depth intervals. During the PUFFALIS expedition, the 0-200 m layer is thus sampled by two nets each integrating 100 m depth, i.e. a resolution of 100 m.

The TAPS has six ultrasonic transducers or transducers that emit at high frequencies, from 265 kHz to 3 MHz. This instrument has been designed to detect, in particular, the meso-zooplankton, a range of animals > 200 ?m dominated by copepods. The latter are present in all oceans of the world and are essential prey for larger zooplankton and for small pelagic fish.

A mathematical treatment by inversion of the multifrequency data, using an acoustic diffusion model adapted to copepods, makes it possible to infer the composition into size classes of the meso-zooplanktonic community detected at each depth of the profile. By repeating sampling at the same sampling station at day and at night, the nycthemeral migration of animals can be observed.

As observed here during the PUFFALIS expedition, there is often a greater concentration of zooplankton in the mixing layer, that is, the warmer section of the water, or the first 40 meters below the surface in the present case. It is mainly the smaller zooplankton that concentrates there, while the bigger zooplankton occurs deeper during the day and migrates upwards to feed at night. The day the biggest animals of the zooplankton protect themselves from predators by staying deeper. The peaks observed at around 100 m at night are just above the maximum fluorescent depth, which is the interesting depth for phytophagous animals. With the profile stopping at 200 m, it is possible that the animals detected at night come from even deeper.

20170330_1Starting the TAPS cast

20170330_2Some profiles along depth of the 6 frequencies of the TAPS (right) and the temperature profile (left)

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20170330_4

Yesterday was a special day. The problems on the hydraulic system needed to be taken care of. The mechanics worked hard all day and a good part of the night too to repair all the system. We could not sample last night but the repairs were necessary to continue the cruise. We made the most of the day by conducting a shore-offshore transect to acquire acoustic data.

This type of event highlights the importance of the crew during any scientific cruise. The R/V Alis crew is composed of the captain, his first and second officers working in the bridge. There are also 3 persons working in the engine room: the chief engineer, the first and the second engineer. On the deck 4 crew members are dealing with all the instruments: the bosun and three seamen. And to keep everybody in good spirit, there is the chief cook and his assistant.

The crew is really enthusiastic and we thank them for their professionalism, their availability, their kindness and their good spirit.

20170329_1The captain and the first engineer

20170329_2The first and the second officers

20170329_3The chief and the second engineer

20170329_4The bosun

20170329_5The seamen

20170329_6The chief cook and his assistant

Yesterday afternoon, on the screen of the echo sounder, strong echoes were visible at all frequencies. Although the crew were resting, they kindly agreed to return on the deck to put the micronekton net into the water and try to capture the organisms producing these echoes. According to the position of the trawl, we passed exactly through the core of the detection. We were anxious to see what had been trawled. Only a few gelatinous organisms, some small fish and some shrimps were captured. It is possible that the detections corresponded to fast-swimming animals which were thus able to avoid the net.

Last night, at sampling station 16, the trawling was delayed because of a hydraulic failure. We were eventually able to deploy the trawl late in the evening. But only a few minutes before hauling the net back aboard, a pipe of the hydraulic system gave way. A fast repair was made to retrieve the net, after a little more than 3 hours of fishing instead of the usual half hour. A quantity of ostracods (small ball-shaped crustaceans) was collected, as well as anchovy, lantern fish, juveniles of reef fish and eel leptocephala. Trawling was done at a depth of 100 m and yielded a mixture of shallow-water organisms and deep-water organisms.

20170328_1Screenshot of the echo sounder, showing dense aggregations of organisms a few tens of meters below the surface

20170328_2This was the whole harvest of the afternoon: disappointing

20170328_3The fish collected during the impromptu trawling operation of the afternoon

20170328_4At a depth of about 100 m, after three hours dragging the micronekton net: a soup of ostracods, decorated with pelagic fishes

20170328_5Delicate and transparent, subtly adorned with dots and dashes: the leptocephala of a moray eel

20170328_6Flying fish were seen at the bow of Alis. With an elegant movement of its tail, this one draws its signature onto the surface of the sea

Ocean currents can be measured to a certain depth on oceanographic ships. They use the S-ADCP instrument (Ship Borne Acoustic Doppler Current Profiler), which is based on the Doppler effect to measure the water currents. The principle is based on the fact that there are particles in the water moving passively according to the water masses. The S-ADCP is a sonar that sends an acoustic wave under the ship at a given frequency and measures the frequency of the backscattered signal. As particles move with the water mass, the returning frequency of the acoustic waves is modified and particle displacement speed (the ocean current) is evaluated, just as road radars measure car speeding.

During the first week of Puffalis, we observed a variety of horizontal currents along the ship track. As the ship sailed north/northwest toward the Pindai shearwater colony along the New Caledonian coast during the first days, currents were globally south-eastward in the top 400 meters as expected from the ALIS currents that usually flows in that direction during summer. That ALIS current flows against the prevailing trade winds for a reason that is not yet fully understood.

As we arrived at the Pindai region and started a transect from the coast offshore, the current was still eastward and we moved south along the transect. On return from the farthest point offshore back toward the coast, the current was then mostly westward. We then sailed from Nepoui to the north/northwest along a coastal route where we encountered eastward currents first and westward currents then.

The current variability is illustrated at the larger scale by a map of sea-level on March 22nd, 2017. The map shows that there is a cyclonic eddy (rotating clockwise in the southern hemisphere) lying offshore of our experiment and that we are sampling in that eddy. That situation with an eddy is of interest when studying seabird alimentation as it has been hypothesized that eddies and fronts can structure the food leading to seabird and tuna alimentation.

From the sea-level one is able to measure a proxy of the surface currents which is referred to as the geostrophic part of the currents. The relative discrepancy between the currents measured by the S-ADCP and the currents derived from the sea-level is puzzling. It seems to indicate that at the scale of our sampling, the geostrophic relationship is not valid. It may well be for instance that our currents measured by the ship are biased by the tides which should be removed. Secondly, the satellite image is static taken at the 22nd of March while the ship is moving and spans almost a week.

Another aspect of the S-ADCP is that it functions on the backscattering of the particles. At the S-ADCP frequency (70 kHz), the backscatter mostly “sees” organisms that probably lie between zooplankton and micronekton. Thus it can also be used a proxy for biomass. The map suggests that there are higher biomasses nearby Pindai than anywhere else during our experiment.

20170327_10-400 depth averaged currents of the S-ADCP onboard the R/V ALIS along the ship track denoted by the colored dots for the 18-27 March 2017 time period. Red dots indicate large biomasses of zooplankton/micronecton, blue dots indicate lower biomasses. Arrows indicate eastward currents in blue and westward currents in red. In the background, satellite sea level is plotted on March 22nd together with the geostrophic currents derived from the sea-level

Last night after finishing working at the sampling station, we steamed toward the north before later coming back to last night sampling station. The aim of those trajectories is to acquire continuous acoustic data along the cruise track to determine the micronecton and zooplankton spatial and vertical distribution in the water column.

This morning we did the same series of measurements as last night on the same sampling station to compare the situation by day and by night. Last night the deep maximum of phytoplankton was at 90m depth while this morning it was deeper at 130m depth. It seems there was more zooplankton this morning than last night which is unexpected as there is usually a higher abundance of zooplankton at night. In the trawls conducted at 20m depth, last night we found Myctophidae, or lantern fish and leptocephalus larvae of anguilliform fish as well as a lot of ostracods. This morning qt the same depth and location we found mainly crustaceans larvae.

We conducted a second trawl at 300m depth during the day when the screen of the echosounder indicates there is nothing. We were surprised to find a lot of amber-colored jellyfish.

20170326_1Vertical profiles at night (left) and during the day (right), between the surface and 200 m depth, showing the fluorescence, an index of phytoplankton with a maximum around 130 depth (green curve), dissolved oxygen with a maximum around 90-100 m depth (yellow curve), temperature which is homogeneous between the surface and 60 m depth at night and down to 40 m depth during the day before decreasing with depth (blue curve), and salinity which is homogeneous during the day between the surface and 40 m but disorganized at night in this upper layer (red curve)

20170326_2Crustaceans larvae with impressive spines

20170326_3Leptocephali, larvae of anguilliform fish caught at 20m depth at night

20170326_4Small Myctophidae or lanternfish caught at night at 20m depth

20170326_5Amber colored jellyfish caught at 300m depth

We spent the night anchored in Nepoui  Bay and went again to the sea early this morning. Out of Mueo pass, we crossed hundreds of shearwaters heading north.

After trawling at a depth of about 45 m, we decided to trawl deeper, at about 510 m. The harvest was small but contained very interesting specimens of fish including Sternoptychidae or hatchet fish and many Cyclothone, which are small and transparent fish with many black chromatophores and photophores.

In the middle of the afternoon, by a calm sea, a compact group of four beaked whales surfaced a few hundred meters on starboard. The Alis was then cruising off Vavouto. The depth was about 1040 m. The cetaceans emerged three times, synchronously, before sounding and vanishing. They seemed to be moving away from the ship. In the binoculars, the animals showed their small triangular dorsal fin, slightly falciform, of a dark color, in the posterior part of the paler back, of bronze color. At one point the biggest individual in the group let its head out of the water, but so furtively that it was impossible to distinguish the characters that would have made it possible to identify it to species.

20170325_1Two shearwaters flying as a tandem

20170325_2Two Cyclothone hauled up from the depths of the Coral Sea

20170325_3Fish of the Sternoptychidae family or hatchetfish

Yesterday the weather finally improved and we managed to conduct all the operations planned during the night sampling station. We finished working after midnight and we then steamed towards the land to arrive this morning at 7am in Népoui Bay in the Northern Province. Today is a special day during this cruise as we are meeting students and stakeholders of the Northern Province.

Within the BIOPELAGOS project one of our objective is to build capacities by explaining our work and its interest both to students but also to those involved in the management of natural space and resources.

The scientific team landed in the Népoui peninsula where we met Sophie and Aurélien two of the ornithologists who are tagging the shearwater at night in the Pindai colony. We were expected at Pouembout high school to present our work for about 1h30 to students involved in the management of natural systems and fauna.  Students were very interested and asked many questions, we all enjoyed this moment.

In the afternoon staff from the fisheries services and from the environment department of the Northern Province came onboard the Alis. We explained our work and were able to illustrate all the work we are doing by showing the instruments used. Once again it was enjoyable.

After this day on land and sheltered in a bay, we will leave the coast tonight to reach our next sampling station tomorrow morning at 7am.

20170324_1RV Alis anchored in Népoui Bay

20170324_2Class of natural sciences with the students of the Pouembout agricultural high school in Province Nord

20170324_3Nature guards of the environment department and staff of the fisheries service of the Northern Province visit Alis anchored in Nepoui Bay and listen to Anne’s presentation on acoustics

During this cruise we study the first trophic levels. Particularly we study the zooplankton, those small organisms that feed on the phytoplankton, the primary producers (the equivalent of the vegetal in the terrestrial ecosystems). They are often smaller than 1 mm and they drift with the current. However they can swim and migrate vertically toward the surface or deep waters.

The zooplankton is in turn consumed by small predators such as fish larvae and if it does not have a direct interest for fisheries in our region, it is very important for the whole food web.

We study the zooplankton using a sampling gear with 5 nets that we can open and close at the desired depth. We sample the depth layers of 600-400m, 400-300, 300-200, and 100m to the surface. In general the layer between the surface and 100m depth is the richest.

We collect small quantities of zooplankton that has a pinkish colour and is mainly constituted of crutaceans that we cannot really observe without a microscope. Samples are stored in formalin and they will be analysed later to identify the species present using a microscope, to count them and to determine their weight.

20170323_1Preparing the zooplankton multinet

20170323_2Transferring the zooplankton from the collector to vials for preservation

20170323_3A zooplankton sample

20170323_4A closer look to the zooplankton sample

One of the objectives of the PUFFALIS cruise is the inventory of the micronecton species in the Coral Sea. Some of the individual fishes sampled in the micronecton net are juveniles or larvae. It is often very difficult to identify the latter to species because they do not yet have the morphological characteristics or the colour patterns which make it possible to differentiate them as adults from closely related species.

A useful approach to the determination of an individual to species is DNA barcoding. The species is characterized by a characteristic DNA sequence. This sequence remains the same whatever the stage of development of the individual, from embryo to adult. The DNA sequence of the larva or juvenile thus allows its identification to species by simply searching the same sequence in a reference database established on a collection of adult fish.

Each fish caught in the micronecton net is thus photographed and a sub-sample of tissue (e.g., a fin clip) is kept dry on a sheet of paper. This sub-sample is the source of the DNA which is then sequenced in a laboratory equipped for molecular biology. DNA sequences will be compared to existing databases, which they will contribute to enrich.

20170322_1Extravagant: some of the representatives of the Coral Sea micronekton

20170322_2The tray with the collected fishes sorted by species (left) and paper sheet with the corresponding dry-tissue subsamples (right)

We did our first night sampling station last night. It is not easy to work in such rough sea conditions. It could even be dangerous, especially when manipulating heavy equipment. We decided not to sample the zooplankton as there is a risk of damaging the equipment and injuring those who handle it.

Contrary to what happens during the day, the acoustic signal at night showed us an accumulation of organisms in the so-called epipelagic layer about 45 m under the surface. The small fish, squid and crustaceans that constitute the micronecton migrate towards shallower water at night to feed. During the day, they occur deeper, supposedly to avoid predators that use daylight to spot their prey. We trawled at 45 m depth and were able to sample many ostracods, which are small crustaceans with a spherical shell, Myctophidae or lanternfish which migrated from deeper layers, a number of squids, and leptocephala which are the larvae of eel-like fishes including eels, congers and moray eels.

After a short night we resumed the operations this morning, with the usual series of measurements. The working conditions remained difficult because of the rough sea. We have installed the waterproof casing of a small underwater camera on the net (thanks to our friends from Soproner). Our aim is to obtain images of the animals at the very moment they are caught by the net. We proceed step by step: after having tested the holding device, we now want to test whether the casing resists to the pressure at 200 m depth. When retrieving the casing, we observed droplets of water inside the casing, which lets us question the water-tightness of the o-ring. We are going to ty again.

20170321_1The catch of the night; the small dots are ostracods, small round crustaceans

20170321_2A Myctophidae or lanternfish

20170321_3Setting up the underwater house of the camera on the trawl to test if it is waterproof

20170321_4A wedge-tailed shearwater passes close to the RV Alis, on sampling station no. 5 this morning

Yesterday night we were unable to reach the night station as initially planned. A water pipe on board was leaking and we had to seek protection in the lagoon to quietly repair it.

This morning we went out to the sea again, to reach sampling station no. 3. The manoeuvers are clearly faster than yesterday: everybody has found their marks now. The ship rolls with the swell, which does not help working on board. Tonight, the wind speed is about 30 knots.

The bad weather affects the quality of the data acquired on a continuous mode, like the echosounder data. The ship sends an acoustic ping to the bottom of the ocean. The acoustic signal is sent back to the ship when it meets fish or other animals. The return signal thus informs us on the quantity of organisms present, and at which depth these organisms occur. This tool is a precious one, for it enables the detection of fish schools. Here, we use acoustics to estimate the depth at which we will tow the trawl, so as to correctly sample the micronecton.

20170320_1Inside the scientific room, in front of the echosouder screens

20170320_2The acoustic signal at four different frequencies. The white vertical bars result from a lack of signal at reception, because of the bad sea

20170320_3Some of the juvenile fishes collected today with the micronecton net

We arrived at the first sampling station early this morning. The land was still visible. The echosounder indicated a depth lower than 1000 m. As some of the instruments are immersed down to 600 m, we have to ensure that sufficient depth remains under them to avoid hitting some possible underwater features. We had to move offshore until we reached grounds with 1000 m depth.

The operations started soon after 07:00 this morning. Two rosettes with sampling bottles and CTD, the instrument that yields information on temperature and salinity according to depth, were cast. A fluorescence sensor also enables us to locate the deep chlorophyll maximum. This morning, this peak was remarkably shallow, at 68 m, when usually it occurs at around 100 m depth.

As usual at the beginning of this kind of expedition, adjustments are necessary. The TAPS acoustic profiler, which gives acoustic data on the zooplankton did not run at first cast, but no problem occurred at the second cast. Fine-tuning was also compulsory with the zooplankton net. The yield of the first trait of micronecton net was relatively poor: a few gelatinous organisms, a few stomatopoda larvae, and, luckily, a beautiful lobster larva. The second micronecton net enabled us to harvest a number of small fishes including a cornetfish, a frogfish, a juvenile yellow trevally, a couple of small flatfishes, and a superb surgeonfish juvenile.

At the surface of the sea, the ballet of shearwaters and petrels indicates the proximity of the Pindaï breeding colony. Tomorrow morning, we will start working at the second day-time sampling station, much further offshore.

20170319_1On the deck we can see the zooplankton net, the rosette to collect water on the right and above the blue micronekton net

20170319_2A stomatopoda captured in the micronecton net: transparent, but wearing an armor ornamented with sharp spines

20170319_3A small flatfish, barely 3 cm long, captured in the open ocean

20170319_4The wedge-tailed shearwater, master of the wind, master of the ocean

We left Noumea harbour this morning at 10am under a clear sky. We are steaming towards the north to reach Pindaï area in the northern Province to start sampling the following morning. We made the most of the calm sea while we were in the lagoon protected by the reef and we conducted a safety exercise. Seven short and one long siren-call mean we have to abandon ship. Everybody has to grab their own life jacket and wear it and also grab their own survival suit. We check that all the crew is present and we receive some safety information from the officers. It is now time to try and wear the survival suit, a dry suit that allows surviving longer is the water in case of sinking.

After the exercise we continue to organise all the equipment and we start preparing the vials for the first sampling station the following morning. We also prepare the zooplankton net which has 5 nets fixed to a frame with a mechanism that allow to successively open and close each net to samples different layers of the water column.

It is now 6pm, birds are observed all around the vessel. From the porthole we can see about 30 birds that are flying towards the land.

20170317_1RV Alis leaves Noumea harbour

20170317_1Safety exercise

20170318_3Assembling the zooplankton net

20170317_1Hundreds of shearwaters were seen this afternoon off the reef, flying over the ocean looking for prey

Last day to prepare everything before departing. We spent the day getting all the equipment onboard. There is a lot of equipment to try and fit in a small lab and we need to make sure everything is easily reached but at the same time we need to make sure it will not move in case of bad weather. It is a little bit like a Tetris game.

The crew is also very busy to prepare the vessel and particularly because we are using new equipment compared to previous cruises. We have a smaller trawl but a bigger CTD with 12 bottles instead of 8. We need to use the large winch and the crew has to build a protection box around it to avoid the trawl to get tangled in it.

We are 18 people onboard leaving for 2 weeks so it requires a lot of preparation in the kitchen. This is the last day to get all the food needed and particularly fresh fruits and vegetables. But Jacques and Gaby, the kitchen crew, are used to it and we know we will be well feed and will have enough to eat.

20170317_1Tetris game in the lab

20170317_2Protecting the main winch to avoid that the micronecton trawl, in blue above, gets tangled in the winch

20170317_3Fresh fruits and vegetables for 2 weeks

20170317_4Ready for a new cruise for the Biopelagos project (BEST 2.0 programme of the European Union)

20170317_5R/V Alis in Noumea Harbour

 

Summary

Still in the framework of the BIOPELAGOS project, we are getting ready to go back at sea for yet another cruise in New Caledonia waters, a few months after the NECTALIS 5 cruise. This cruise is somewhat different from the Nectalis series and it has been named PUFFALIS in reference to “puffin fouquet”, the French name of the wedge-tailed shearwater (Ardenna pacifica), a well-known seabird in New Caledonia. It has a dark plumage and we particularly notice it from January to April when it reproduces. It digs burrows in the sand and bird couples gather into colonies located by the seaside. At night their characteristic calls sound like baby cry and keep the campers awake.

 

The goal of the Puffalis cruise is to characterise the feeding grounds of the shearwater at sea. Are there any specific current conditions? Is there a lot of zooplankton there? What are the fish that can be preyed upon by the birds? Is there a need to protect those feeding grounds? Do the tuna come and feed at the same place? These are questions we will try to start answering but we are expecting more questions to be raised.

For this cruise we have the support of a scientific team on land that started working early March. They are ornithologists who are working on the shearwater colony located in Pindaï in the northern province of New Caledonia. They glue small GPS on the back of the seabirds, let them go several at sea where they feed and recover the equipment when the birds come back to their burrow to feed their chicks.

The information collected is crucial as it indicates where the birds are feeding at sea. With those data we have been able to establish a sampling plan to go and collect data at sea. As for the Nectalis cruises we collect data on the physical and chemical characteristics of the ocean (currents, temperature, salinity, nitrate, silicate, phosphate…), and on the biology (phytoplankton, zooplankton and micronekton, the small fish, squids and crustaceans eaten by the seabirds and the tuna)

The Puffalis cruise is starting on the 18th of March and a team of 6 scientists from IRD and SPC will get onboard for 2 weeks, coming back on the 2nd of April. We planned to stop in the Northern Province to meet students to explain them our work and exchanges ideas.

puffin
A wedge-tailed shearwater (Ardenna pacifica) in front of its nest


trajetsThe thin lines are seabird tracks at sea and the thick dark line with white diamonds shows the provisional cruise plan of the Puffalis cruise


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Last Updated ( Tuesday, 04 April 2017 11:13 )
 
 
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