"Inter-callibration" Sampling

mercredi 3 juin 2015
par  Dorian GUILLEMAIN, Romain DAVID
popularité : 12%

Index of "Inter-calibration?"
1. Principle
2. Method
3. Sampling
4. Deliverables
5. To summarize
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How to cite this content :

David R., Arvanitidis C., Çinar M.E., Dubar J., Dubois S., Erga Z., Guillemain D., Sartoretto S., Thierry de Ville d’Avray L., Zuberer F., Chenuil A., Féral J.-P., (2014), with contributors : Açik Çinar S., Andral B., Aurelle D., Aysel V., Bakir K., Bellan G., Bellan-Santini D., Bouchoucha M., Celik C., Chatzigeorgiou G., Chatzinikolaou E., Chenesseau S., Dağli E., Dailianis T., Dimitriadis C., D’Iribarne C., Doğan A., Dounas C., Egea E., Elguerrabi W., Emery E., Evcen A., Faulwetter S., Gatti G., Gerovasileiou V., Güçver S.M., Issaris Y., Katağan T., Keklikoglou K., Kirkim F., Koçak F., Koutsoubas D., Marschal C., Önen M., Önen S., Öztürk B., Panayiotidis P., Pavloudi C., Pergent G., Pergent-Martini C., Poursanidis D., Ravel C., Reizopoulou S., Rocher C., Ruiton S., Sakher S., Salomidi M., Sarropoulou E., Selva M., Sini M., Sourbes L., Simboura N., Taşkin E., Vacelet J., Valavanis V., Vasileiadou A., Verlaque M. Protocols for monitoring of coralligenous habitats of mediterannean (Coralligenous based Indicators to Evaluate and Monitor the "good ecological status" of the MEDiterranean coastal waters) Protocoles de suivi du coralligène en méditerranée (Coralligenous
based Indicators to Evaluate and Monitor the "good ecological status" of the MEDiterranean coastal waters).

[§ 1] Two sampling techniques will be applied :
- Sampling along a permanent transect? (Figure 1(1)), starting from a physical mark and shooting photographs all along the transect, at constant depth (+/- 1 m) (Figure 2). The permanent transect will be 10 m long, in order to allow obtaining at least 20 photo-quadrats for the larger sampling unit that will be used (50 cm x 50 cm).
Sampling along random transects (Figure 1(2)), which imply discontinuous shooting at constant depth (+/- 1 m), focusing on selected profiles.

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Figure 1 : permanent and random transect

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Figure 2 : margin of error of a diver’s trajectory

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Figure 3 : photo-quadrat example

[§ 2] In addition, a third sampling technique will be tested. A positioning frame, i.e. a frame whose sides overstep each corner of 15 cm, will be arranged on the substrate in correspondence to a fixed mark or a remarkable point (easy to find again). This will allow the exact positioning of 9 photoquadrats around a point (Figure 4) respecting the horizontality. The way to ensure horizontality remains to find, but the use of a plumb-line could be fine. This system greatly reduces the variability related to the trajectory of the diver on a long transect.

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Figure 4 : photo-quadrats’s sampling method with a positioning frame

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Figure 5 : Illustration of the two types of quadrat used and a photograph diver making a photo-quadrat

Photo-quadrats achievement on permanent transect for the inter-calibration phase

[§ 3] The diver who maintains the quadrats moves along the permanent transect starting from the mark, while unrolling the decametre and monitoring its depth, in order to achieve 20 photo-quadrats on a 10 m long transect. The other diver takes a picture at each position of the quadrat.

Sampling of photo-quadrats on random transect for the phase of comparison of the variability of metrics values between permanent transect and random transect
[§ 4] This sampling is done on the same site?, on a comparable place to the one of the permanent transect (avoid taking two locations that are obviously very different). It will be necessary to dive again there to achieve the photo-quadrats randomly. An additional dataset can be provide later on, using the photo-quadrats achieved on the permanent transect and select some of them randomly.

Random sampling of photo-quadrats on a determined profile? for the phase of data contextualization

[§ 5] Divers look for the two determined profiles, and focus on the photography on these profiles.
Slope and rugosity have a significant part (light) in the distribution of species. Sampling should be done alongrandom transectsshowing homogeneous slope and rugosity : one transect on a vertical zone, one transect on an horizontal zone, and one transect on a zone under an overhang. Since all combinations can’t be tested, only the 2 or 3 most frequent combinations in each region will be tested.

Work time quantification
Current tests of implementation show that it’s possible to achieve in a single dive (15 min) : two sampling transects of 10 m each, or quadrats photographed.

Nomenclature and photos archiving

[§ 6] Each photograph (photo-quadrat) should be labeled according to a precise nomenclature, defined below :

[program]_[site]_[date] _D[depth]_T[n°transect]_Q[n°quadrat] _[doer] Example : CIGESMED_CAS _20140123_ D1_T02_Q08_AA01

Photo’s labels must be written on the notepad used during the dive for the complementary observations by the diver. A paper (photocopies) and digital (scan) archive of the notepad should be createdand respect the same nomenclature typology as the photographs.

All data should be sent to the program manager or the database manager (romain.david@imbe.fr, France).


- Deadline : 14th December 2015
- Please add comments for each paragraph (§) by means of a corrected new version (one form per §)
- It is recommended to add scientific references if necessary

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