Effects of water quality on non-coral communities: surveys of macroinvertebrates, benthic microalgae, and benthic foraminifera at sites along a water quality gradient in Aua, American Samoa in 2022

This metadata record describes the non-coral bioindicator datasets funded by the NOAA Coral Reef Conservation Program (CRCP) Project Number 31303 to study effects of land-based sources of pollution (LBSP) in Aua, American Samoa. In September 2022 Ecosystem Sciences Division (ESD) scientists of the Pacific Islands Fisheries Science Center (PIFSC) flew into American Samoa to survey 18 sites along a water quality gradient off of Aua. This specific metadata record refers to the quantitative analysis of benthic foraminifera, benthic microalgae, and macroinvertebrates from samples collected between 9-28 September 2022. Samples were preserved in the field, and brought back to the NOAA Inouye Regional Center (IRC) and analyzed via microscopy. Collection methods for each bioindicator were as follows:

(1) Benthic foraminifera: Sediment samples were collected (Sept 26, 2022) using a small sediment corer (60 ml syringe with the tip removed and a stopper placed there instead). Only the top 3 cm were retained. Under the microscope, benthic foraminifera were picked out of the sediment and identified.

(2) Benthic microalgae: Microscope slides were deployed (Sept 11-26, 2022) on the seafloor at each site for 2 to 3 weeks and the benthic microalgae that settled will be fixed and preserved in Lugol's solution and analyzed. Microalgae included diatoms (pennate and centric), dinoflagellates, chlorophyta, and cyanobacteria.

(3) Macroinvertebrates: Plastic scouring pads were deployed (Sept 11-26, 2022) and attached to the substratum via zip-ties for 2 to 3 weeks. The scouring pads were removed after the settlement period, all plastic zip-ties and additional waste were removed from the reef. Macroinvertebrates that settled on the scouring pad were placed into sampling jars and fixed and preserved with 4% formalin, and subsequently analyzed under the microscope.