Sampling area and protocol
A total of 92 water samples were collected during October and November
2017 along the south coast of the Bird’s Head region of West Papua (500
km) across different habitats but mainly coral reefs (Fig. 1). Samples
were collected in DNA-free plastic bags at the surface from a dinghy
boat, at depths between 10 – 100m during close circuit rebreather
dives, and (iii) at depths between 100 - 300m using Niskin water
samplers. A pressure and temperature sensor was coupled to the Niskin
bottle to control the sampling depth and characterize the water mass via
the vertical temperature profile. For each sample, 2L of seawater were
filtered with sterile Sterivex filter capsules (Merck© Millipore; pore
size 0.22µm) using disposable sterile syringes. Immediately after, the
filter units were filled with lysis conservation buffer (CL1 buffer
SPYGEN©) and stored in 50 mL screw-cap tubes at -20°C. A contamination
control protocol was followed in both field and laboratory stages ((27)
Goldberg et al 2016; (26) Valentini et al. 2016). Water sample
processing included the use of disposable gloves and single-use
filtration equipment, and the bleaching (50% bleach) of Niskin water
sampler.