Interannual and Regional Differences in Krill and Fish Prey Quality along the Western Antarctic Peninsula

Polar zooplankton and fish safeguard against the seasonality of food availability by using the summer months to build large reserves of lipids, which in turn are utilized to meet the metabolic demands of apex predators such as penguins, seals, and whales. A warming trend in the northern part of the western Antarctic Peninsula (WAP) has led to a decrease in perennial and summer sea ice, an increase in heat content over the shelf, and lower phytoplankton biomass, which could affect prey quality. We compared prey quality, including elemental (C, N) content and ratios, total, neutral, and polar lipid content, and energy densities, of known top-predator prey items (krill Euphaush1 superba, 17Jysanoessa macrura, and Euphausia crystallorophias; and fish Pleuragramma antarcticum, and Electrona antarctica) along the W AP latitudinal gradient in January of 2009-20 II as part of the Palmer Antarctica Long-Term Ecological Research study. E. antarctica had the highest prey quality in terms of total lipid content and energy density, followed by T. macrura and P. antarcticum, then E. c1ystallorophias and E. superba. For all species, variations in carbon and nitrogen content were best correlated with by the animals\u27 neutral lipid content, in that animals with larger neutral lipid stores had significantly higher carbon and lower nitrogen content. Across all sexes and maturity stages, E. superba in the South had ca. 20% higher total lipid content than E. superba in the North. Total lipid content was also significantly higher in the South for E. crystallorophias, though this was largely due to the presence of larger individuals in the south combined with a significant positive relationship between length vs. weight-specific total lipid content for this species. For all prey species except T. macrura, there was a positive relationship between latitude or 0-120 m integrated Chi a vs. lipid content (neutral, polar, or total lipids), and a negative relationship between 0-120 m mean water temperature vs. lipid content. Trends opposite to those above found for T. macrura, suggest an optimal habitat for this species in the northern W AP which is characterized by warmer temperatures and lower Chi a. Patterns in Chi a were more important than upper water column temperature in explaining the observed latitudinal trends. If regional warming persists, the prey quality trends described for E. superba, combined with their regional abundance decline in the northern, coastal W AP could affect the ability of apex predators that rely on E. superba to meet their energetics demands

Advancing the Sea Ice Hypothesis: Trophic Interactions Among Breeding Pygoscelis Penguins With Divergent Population Trends Throughout the Western Antarctic Peninsula

We evaluated annual and regional variation in the dietary niche of Pygoscelis penguins including the sea ice-obligate Adélie penguin (Pygoscelis adeliae), and sea ice-intolerant chinstrap (Pygoscelis antarcticus) and gentoo (Pygoscelis papua) penguins, three species that nest throughout the western Antarctic Peninsula (AP) to test the sea ice trophic interaction hypothesis, which posits that penguin breeding populations with divergent trends, i.e., declining or increasing, are reliant on differing food webs. Our study relies on values of naturally occurring carbon (13C/12C, δ13C) and nitrogen (15N/14N, δ15N) stable isotopes as integrated proxies of penguin food webs measuredover three years at three different breeding colonies. At Anvers Island in the north, where reductions in sea ice and changes in breeding population trends among sympatric sea ice-obligate (Adélie) and sea ice-intolerant (chinstrap and gentoo) penguins have been most notable, our analyses show that all three species of Pygoscelis penguins became more similar isotopically over the reproductive period

Regional differences in quality of krill and fish as prey along the Western Antarctic Peninsula

The warming trend in the northern part of the Western Antarctic Peninsula (WAP) has led to a decrease in perennial and summer sea ice, an increase in heat content over the shelf, and lower phytoplankton biomass, which could affect the prey quality of krill and fish that are utilized by apex predators. We compared prey quality metrics, including elemental (C, N) content; total, neutral, and polar lipid content; and energy densities of known penguin prey items including krill (Euphausia superba, Thysanoessa macrura, and E. crystallorophias) and fish (silverfish Pleuragramma antarcticum and the myctophid Electrona antarctica) along the WAP latitudinal gradient each January from 2009 to 2011. E. antarctica had the highest prey quality in terms of lipid content and energy density, followed by T. macrura and P. antarcticum, then E. crystallorophias and E. superba. For all species, variations in C and N content were most strongly correlated with the animals’ neutral lipid content, in that animals with the larger neutral lipid stores had significantly higher C and lower N content. Across all sexes and maturity stages, E. superba in the southern study region had ca. 20% higher total lipid content than E. superba in the north, and a stepwise multiple linear regression analysis showed that latitude, sexual differences, and upper water column temperatures best explained this regional difference in lipid content. This regional variability in E. superba prey quality could affect the ability of apex predators that rely on E. superba to meet their energetic demands, and should be considered in future modeling efforts

Participatory principles in practice: Designing learning spaces that promote wellbeing for young adolescents during the transition to secondary school

With a view to informing school designing projects that foster the wellbeing of Middle Years students, this chapter explores the participatory designing process of the Junior Secondary Precinct at Cannon Hill Anglican College in Brisbane, Australia. The chapter highlights the importance of including student voice in the designing process and the benefits of collaboration between school community members and architects. The Cannon Hill College design project sought to create a learning environment that would respond to the wellbeing needs of Middle Years students who experience various challenges in their transition from primary to lower secondary school. The project members recognised that student-focused spatial design can enhance their motivation, learning engagement, changing relationship dynamics and developing self-identity. As demonstrated, the participatory designing process approach led to positive wellbeing and pedagogical outcomes