Bioenergetics team completes field collection; preliminary biomass maps show vegetation and invertebrate pulses

Lauren (PhD candidate) presented the bioenergetics project’s quarterly update: three years of field sampling are complete for 240 sites across six wetland systems, with samples taken in April, August and November. The study converts biomass measures (macroinvertebrates, submerged aquatic vegetation, seeds) into caloric supply estimates paired with species‑specific demand to estimate metrics such as "duck‑use‑days."

Processing status: the team reported roughly 1,140 of 1,400 core and water samples processed; lab capacity increased (from three to six technicians), and a short supply hiccup (vials) was resolved. Preliminary August results indicate about 61 macroinvertebrate groups with the top 10 taxa composing ~90% of biomass. Ostracods, daphnia and copepods are prominent contributors to the open‑water biomass; Lauren noted that shell weights for some taxa have not been adjusted yet and will be corrected before final caloric calculations.

Spatial comparisons between August 2023 and 2024 show strong year‑to‑year differences: 2023 had larger vegetation flushes and greater surface‑water cover in some impounded sites, while 2024 recorded an approximate 10‑centimeter drop in water depth across sites and different vegetation distribution. Lauren said that timing of water delivery and managed impoundment operations plausibly explain much of the interannual variation and that the full bioenergetics outputs will be used to test how changes in water levels affect calorie supply and bird use.

Next steps include completing processing and converting biomass into caloric units, integrating field measures with depth and water‑quality drivers, and embedding the results into a predictive bioenergetics framework for managed and unmanaged wetlands.