You are here: /main/research expeditions/CReefs 2006/Collection/Ekman

Census of Marine Life, Census of Coral Reefs Expedition to French Frigate Shoals (October 2006)

Ekman/Van Veen Grab

Ekman Grab. Photo: Jim Maragos

Lead Scientist: Gustav Paulay
Target Habitats: Lagoonal Sands
Target Organisms: Infaunal organisms

Description:
The Bottom Grab sampler is designed for sampling in soft bottomed substrate. It is particularly ideal for slow moving or sedentary species. As the sampler is lowered from the boat, two hinged upper lids swing open to let water pass through and close upon retrieval on the substrate preventing sample washout. The grab we will use is 12 inches long,
8 inches wide and cylindrically shaped. It will be used at depths of approximately 30 meters and deeper. It will retrieve a sample of a given surface area of benthic substrate and the organisms on and within that substrate. The advantage of a grab is that it can be deployed and retrieved quickly, bringing up a small amount of sediment and getting a perfect sample with very little bottom disturbance. From this, sand sampling can be done, providing samples with distinct fauna from deeper depths. This method of sampling is an extension of the previously described sand sampling and will be used to reach sand habitats that are beyond SCUBA depths. If we are able to obtain one, in place of the Ekman grab, we would prefer to use the Van Veen grab. While the Ekman grab would be useful for taking very small samples of minute animals from extremely fine sediment, the Van Veen grab is used to collect larger animals on sandy sediment in deep water.

Ekman grab

Back to collection methods

Ship Logs:
Day-by-day activities of the expedition.

Journals:
Daily or semi-daily personal journal entries by the particpants in the expedition. These journals do not necessarily reflect the positions of any of the agencies connected with this project.

Interviews:
Interviews with expedition participants, scientists, vessel crew, educators, etc.

Features:
Highlights or special information such as interesting discoveries, articles or related research.