Deployment

Important considerations:

The ARMS will be deployed on a horizontal plane, on a substrate that is representative of the habitat to be studied. Care should be given to the choice of location for each ARMS unit and it is advised not to deploy on soft substrate like mud or sand to avoid the risk of the ARMS being partially or completely buried over time.

The anchoring method will depend on the substrate. The most common method uses 4 stainless steel rods hammered in the substrate through the 4 holes in the corners of the base plate. This method is described below. Other possibilities include attaching the ARMS to heavy weights placed on the bottom or drilling eyebolts in the hard substrate and securing the ARMS with cable ties or zip-ties.

Materials:

  • 1 fully assembled ARMS unit
  • 4 24-inch stainless steel stakes
  • 1 heavy duty sledgehammer
  • Heavy duty zip ties (24-36”)
  • 1 GPS
  • 1 underwater camera
  • 1 metadata spreadsheet

Procedures:

  1. Place the ARMS unit on the substrate in a horizontal position
  2. For easier hammering of the stakes in the substrate and a stronger hold of the stakes on the unit, the stakes may be sharpened and/or one end (approximately 1-2 inches) may be bent at 90 degree angle with the help of a vice and this can become a larger target for hitting with the hammer.
  3. Place the stake in the base plate hole and hammer it in the substrate at an angle so that the ARMS unit is secured at the bottom. If the stakes are bent at one end, hammer the 4 stakes into the 4 base plate holes until the bent end is securely blocked by the base plate if possible.
  4. When the ARMS are secure, document the site with photos and mark a GPS point of the site.
  5. Record deployment metadata locally and via this portal when you have access.

* Note: When hammering stakes into the substrate is not an option, it is possible to use other anchoring methods or a combination of methods:

  • Drilling with a pneumatic drill and installing eyebolts on a hard substrate allows the ARMS to be secured with cable/zip ties.

  • Attaching weights to the sides of the base plate with zip ties to help with anchoring the unit to the bottom. Make sure that the weights do not obstruct the water flow into the ARMS layers.

  • Using heavy-duty zip ties as a complement to secure the ARMS to surrounding structures such as rocks.

Illustrations:

ARMS deployed in Indonesia, anchored using 4 stainless steel stakes

ARMS anchored using bolts drilled into the hard substrate and zip ties

Comments:

Anne CHENUIL (not verified) commented on 08/30/2017 - 06:37 - Permalink

It would be great to provide a Spanish and a French version, at least, of the protocol of installation (and recovery) underwater. Indeed, all researchers work in English but they are not familiar with the underwater fixation vocabulary... Scuba-divers helping them may not be familiar with english in some cases (when we have to ask diving clubs for instance). We of course can read the protocol and understand it, but I am sure some local managers who may have looked at it rapidly in their own language may hesitate in a foreign language. Thank you in advance

Anne

Laetitia Plaisance (not verified) commented on 09/08/2017 - 11:11 - Permalink

Hi Anne,
Thank you for you message. We agree on the importance of developing protocols in other languages as the scope of the ARMS program is international in nature. We are working on it!
Best regards,
Laetitia