Greetings from Kiska!

North Head, viewed from our anchorage in Kiska Harbor

Benthic respiration chamber deployed in a transition zone

Sadie here with a brief expedition update and a look inside shipboard lab operations!

​The next island along our route was Agattu, but inclement weather forced us to head East sooner than expected. After a full travel day, we arrived at beautiful Kiska Island this morning. As usual, the Edwards Lab dive team deployed chambers in three different habitat types (kelp, transition, and urchin barren). A quick refresher on what our lab is doing up here in the Aleutians: we’re comparing ecosystem productivity between these three habitats and among different islands in an east-west gradient along the island chain. For this large-scale project, we use clear, flexible chambers to isolate 0.57m^2 patches of the seafloor for 24-hour periods, meanwhile collecting changing oxygen concentration, temperature, and light data within these chambers. The organisms in nearshore benthic habitats all use or produce oxygen during photosynthesis or respiration, so we use oxygen concentration to assess the activities of algae and animals within the chambers.

​​These data help us estimate productivity from the community as a whole; however, we want to go deeper into the story! Algae and invertebrate animals from inside the chambers are collected and brought back to the ship and further analyzed to help us understand how individual members of the community are contributing to our large-scale production estimates.

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Dr. Ju-Hyoung Kim saying hi from behind an active photoincubation of coralline algae

A green urchin in a respiration incubation chamber

Sadie conducting a photoincubation with green algae

That’s where Dr. Ju-Hyoung Kim and I come in. We’re using small-scale methods at the individual level to add details to the large-scale benthic chambers that give us community-level data. In the shipboard laboratory, we have set up small glass incubation chambers that hold one organism at a time. By controlling temperature and light, we can measure the change in oxygen concentration via photosynthesis (algae) and respiration (animals). Coupled with biomass data from the chambers, we hope tease apart how each species contributes to the larger productivity estimate within the benthic chambers that the dive team deploys in the field.

These experiments in the field and in the laboratory allow our group of scientists to come together and work toward a common goal, which is to understand more about the valuable ecosystems of the Aleutian Islands!

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Usually our common goal is research-related, but sometimes we get together and make algae art!

Featured here in an herbarium pressing: Neoptilota asplenoides, Kallymeniopsis sp., Odonthalia setacea, Neinburgia prolifera, Callophyllis sp., and more.

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Catch you at the next island!
--SS

South Head viewed from our anchorage in Kiska Harbor.