Expanding collaborative autoethnography into the world of natural science for transdisciplinary teams.

Wicked problems such as climate change and the COVID-19 pandemic require authentically transdisciplinary approaches to achieving effective collaboration. There exist several research approaches for identifying the components and interactions of complex problems; however, collaborative autoethnography provides an empirical way to collect and analyze self-reflection that leads to transformative change. Here, we present a case study of collaborative autoethnography, applied as a tool to transform research practice among a group of natural and social scientists, by constructively revealing and resolving deep, often unseen, disciplinary divides. We ask, "How can natural and social scientists genuinely accept, respect, and share one another's approaches to work on the wicked problems that need to be solved?" This study demonstrates how disciplinary divisions can be successfully bridged by open-minded and committed collaborators who are prepared to recognize the academic bias they bring to their research and use this as a platform of strength.

Trace metal biomonitoring in the east Gippsland Lakes estuary using the barnacle Amphibalanus variegatus and mussel Mytilus edulis.

The Gippsland Lakes estuary, a Ramsar listed wetland, in Victoria, Australia, is an area of potential concern for metal pollution due to influxes of human population and associated anthropogenic activities. A biomonitoring exercise was undertaken where the concentrations of 9 metals (Cr, Fe, Cu, Zn, As, Se, Ag, Cd and Hg) were analysed in the soft tissue of two common sessile invertebrates: the mussel Mytilus edulis and the barnacle Amphibalanus variegatus from 6 locations on two different occasions throughout the Gippsland Lakes estuary. A salinity gradient exists in the Lakes, from seawater at Lakes Entrance in the east, decreasing down to < 10 PSU in the west at Lake Wellington during times of rainfall, which is a major factor governing the growth and distribution of both species. Dissolved metal levels in general were low; however, Cu at most sites exceeded the 90% trigger values, while all Zn concentrations exceeded the lowest 80% trigger values of the ANZECC marine water quality guidelines for environmental health. Elevated levels of Cu and Zn were found particularly in barnacles at some sites with environmental contamination due to leaching from anti fouling paints and sacrificial zinc anodes. Elevated levels of Ag and Cd were found in mussels at the Hollands Landing site, which is immediately adjacent to a boat ramp, and Cd and Ag at this site are suspected to originate from inland anthropogenic sources. Concentrations of As in M. edulis across all 6 sites in both sampling periods had mean wet weight As concentrations exceeding the maximum level stated in the FSANZ guidelines. A. variegatus contained elevated levels of Hg especially at the North Arm site with a maximum of 13.6 µg Hg/g dry wt., while A. variegatus also showed temporal changes in Hg concentrations across sites. The maximum Hg concentration found in Mytilus edulis was 1.49 µg Hg/g dry wt. at the Hollands Landing site. Previous contaminant studies of biota in the Lakes have targeted sampling of singular predatory or migratory species, such as Black Bream (Acanthopagrus butcheri) and the Burrunan dolphin (Tursiops australis). This is the first biomonitoring study conducted on sessile organisms to assess metal contamination in the system.

Some insights into how barnacles survive as sessile organisms.

During routine chemical analyses of the stalked ibliform barnacle Chaetolepas calcitergum Buckeridge & Newman 2006, peaks of more than 7% (by dry mass) of bromine were detected. Although bromine ions occur in seawater (up to 66 ppm), this level of accumulation, in the soft tissue of the barnacle, is extraordinary. Organic concentration of bromine compounds occurs in a number of invertebrates, such as algae and sponges, but this is the first record of elevated bromine in goose barnacles. The high accumulation of bromine compound(s) is most likely a defense mechanism. The present paper includes a review of the mechanisms deployed by barnacles to repel predators.

Temperature stability of a dichroic atomic vapor laser lock.

We have investigated the temperature stability of the dichroic atomic vapor laser lock laser frequency lock method. We find that, in general, the lock exhibits significant temperature sensitivity, leading to laser frequency drifts as large as tens of MHz/K. However, for certain configurations of the optical elements of the system, this temperature dependence is reduced to below 1 MHz/K. These temperature-independent points can be found across a broad range of frequencies. We present a numerical model that reproduces the general behavior of the system.