Benthos sampling technique LTT

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The survey has taken place on the radiale of Tiahura since 1987. The marks on the radiale on the beach is a cut in the reef perpendicular to the reef, then the radiale passes through 3 coral heads at station 8 and then is aligned to the yellow buoy attached over -40m in the ocean.

Radiale Benthos Carte
Map showing the marks on the pioneer radiale of Tiahura

A 50m reel (A, see schematics below) is unrolled perpendicularly to the shore. At 25m, perpendicularly to the reel (thus parallel to the beach) another 50m reel (B) is set up. On this second reel, every meter substrate is sampled using a lead weighted line and classified in the following 7 categories:

  • R (Rubble)
  • S (Sand)
  • T (Turf)
  • A (macro Algae)
  • P (Porolithon / coralline encrusting algae)
  • D (Pavement, Dalle in French)
  • C (live Coral)

This is done 22 times from the shore to -25m on the outer slope.

Radiale Benthos
Setup of the 22 stations for benthic survey organised as is during R. Galzin PhD thesis (1985)

References : AUGUSTIN D., GALZIN R., LEGENDRE P., SALVAT B., 1997 - Variation interannuelle des peuplements récifaux du récif-barrière de Tiahura (île de Moorea, Polynésie française). Oceanologica Acta, 20 (5) : 743- 756.

Interactive map


1)  2024-09-02 15:22
Nuku Hiva
2)  2024-09-04
3)  2024-09-09 15:26
Série Galzin
4)  2024-09-30 15:23
5)  2024-11-05 15:23