The Rapid Population Collapse of a Key Marine Predator in the Northern Antarctic Peninsula Endangers Genetic Diversity and Resilience to Climate Change

Antarctic fur seals (AFS) are an ecologically important predator and a focal indicator species for ecosystem-based Antarctic fisheries management. This species suffered intensive anthropogenic exploitation until the early 1900s, but recolonized most of its former distribution, including the southern-most colony at Cape Shirreff, South Shetland Islands (SSI). The IUCN describes a single, global AFS population of least concern; however, extensive genetic analyses clearly identify four distinct breeding stocks, including one in the SSI. To update the population status of SSI AFS, we analyzed 20 years of field-based data including population counts, body size and condition, natality, recruitment, foraging behaviors, return rates, and pup mortality at the largest SSI colony. Our findings show a precipitous decline in AFS abundance (86% decrease since 2007), likely driven by leopard seal predation (increasing since 2001, p << 0.001) and potentially worsening summer foraging conditions. We estimated that leopard seals consumed an average of 69.3% (range: 50.3–80.9%) of all AFS pups born each year since 2010. AFS foraging-trip durations, an index of their foraging habitat quality, were consistent with decreasing krill and fish availability. Significant improvement in the age-specific over-winter body condition of AFS indicates that observed population declines are driven by processes local to the northern Antarctic Peninsula. The loss of SSI AFS would substantially reduce the genetic diversity of the species, and decrease its resilience to climate change. There is an urgent need to reevaluate the conservation status of Antarctic fur seals, particularly for the rapidly declining SSI population.

Year of refusal: crisis and ideology in the Communist Party of Canada, 1956-7

Just as they did for other communist parties around the world, events in 1956 brought a crisis to the Communist Party of Canada (CPC). Khrushchev's Secret Speech and the Soviet invasion of Hungary produced a reckoning with what exactly it meant to be a communist and a marxist-leninist. In Canada, this reckoning would lead to a mass exit of party members and to a precipitous decline in the general fortunes of the party after 1956. In existing histories, this crisis has been presented as though it played out in quite strictly bipolar fashion as a conflict between a growing minority of independent marxists on the one hand and, on the other, a larger group of party leaders and their supporters who remained committed to a Soviet-aligned marxist-leninist politics in Canada. In fact, the ideology of the crisis was more complex. Ideological reactions to 1956 could range, at least, across stalinist, liberal, marxist-leninist, or independent-marxist iterations. Taking 1956 to constitute a year of refusal in the CPC, this essay follows the trajectories of these ideologically distinct 'modes of refusal' and suggests an alternative history.

Technological rejection in regions of early gold innovation revealed by geospatial analysis

In research on early invention and innovation, technological “firsts” receive enormous attention, but technological “lasts”—instances of abandonment and rejection—are arguably more informative about human technological behavior. Yet, cases of technological discontinuance are largely ignored in studies of early innovation, as the lack of robust datasets makes identification and analysis difficult. A large-scale geospatial analysis of more than 4500 gold objects from the Caucasus, an early center of gold innovation, shows a precipitous decline at 1500 BC in precisely the places with the earliest global evidence of gold mining (c. 3000 BC). Testing various causal models reveals that social factors, rather than resource limitations or demographic disruption, were the primary causes of this rejection. These results indicate that prior models of technological rejection and loss have underestimated the range of conditions in which they can occur, and provide empirical support for theories of innovation that reject notions about the linearity of technological progress.

Cost Increments of Electricity Supply to Achieve Carbon Neutrality in China

The Chinese government has set long-term carbon neutrality and renewable energy (RE) development goals for the power sector. Despite a precipitous decline in the costs of RE technologies, the external costs of renewable intermittency and the massive investments in new RE capacities needed to achieve carbon neutrality would drive electricity costs up. Here, we develop a power system expansion model to comprehensively evaluate changes in the costs of electricity supply over a 30-year transition to carbon neutrality, including the effects on the costs of various factors. RE supply curves across China, operating security constraints, and characteristics of various generation units are modelled in detail to assess the cost variations as accurately as possible. According to our results, approximately 5.5 TW of wind and solar photovoltaic capacities would be required to achieve carbon neutrality in the power system by 2050. The electricity supply costs would increase 21.5%, or 10.4 CNY¢/kWh (1.51 USD¢/kWh), which equates to a rise in the effective marginal price of carbon to 1082.6 CNY/t (157.0 USD/t) in 2050. The major cost increments would result from substantial investments in the new RE capacities, flexible generation resources, and network expansion that would be required to achieve carbon neutrality.

Saving the Last Unicorns: The Genetic Rescue of Florida’s Pillar Corals

As stony coral tissue loss disease (SCTLD) swept through the Florida Reef Tract, one of the most severely impacted species was the iconic pillar coral, Dendrogyra cylindrus. As the species’ population experienced a precipitous decline, a collaborative rescue project collected colony fragments for safekeeping at onshore and offshore nursery facilities. Between 2015 and 2019, a total of 574 fragments representing 128 genotypes were collected. These are currently dispersed among five facilities where they continue to provide opportunities to (1) refine best husbandry practices for D. cylindrus, (2) develop treatment options for SCTLD that have been adapted for use on other species, (3) maximize growth and fragmentation to provide the live tissue needed for eventual restoration, and (4) provide a source of parent colonies for assisted sexual reproduction and new genetic diversity. With the wild pillar coral population in Florida at the end of 2020 at less than 6% of its known 2014 population and continuing to decline, the rescued ex situ colonies represent the entirety of the restoration potential for this species in Florida.

Impact of COVID-19 Mitigation Measures on Mosquito-Borne Diseases in 2020 in Queensland, Australia

We describe the impact of COVID-19 mitigation measures on mosquito-borne diseases in Queensland, Australia, during the first half of 2020. Implementation of restrictions coincided with an atypical late season outbreak of Ross River virus (RRV) characterized by a peak in notifications in April (1173) and May (955) which were greater than 3-fold the mean observed for the previous four years. We propose that limitations on human movement likely resulted in the majority of RRV infections being acquired at or near the place of residence, and that an increase in outdoor activities, such as gardening and bushwalking in the local household vicinity, increased risk of exposure to RRV-infected mosquitoes. In contrast, the precipitous decline in international passenger flights led to a reduction in the number of imported dengue and malaria cases of over 70% and 60%, respectively, compared with the previous five years. This substantial reduction in flights also reduced a risk pathway for importation of exotic mosquitoes, but the risk posed by importation via sea cargo was not affected. Overall, the emergence of COVID-19 has had a varied impact on mosquito-borne disease epidemiology in Queensland, but the need for mosquito surveillance and control, together with encouragement of personal protective measures, remains unchanged.

Pinpointing Drivers of Extirpation in Sea Snakes: A Synthesis of Evidence From Ashmore Reef

Over the past decade, vertebrate populations globally have experienced significant declines in distribution and abundance. Understanding the reasons behind these population declines is the first step in implementing appropriate management responses to improve conservation outcomes. Uncovering drivers of extirpation events after the fact, however, requires a careful forensic approach to prevent similar declines elsewhere. The once abundant and species-rich sea snake fauna of Ashmore Reef Marine Park, in the Timor Sea, collapsed dramatically in the early 2000s. No such decline has occurred on surrounding reefs. We synthesise the evidence for this collapse and the subsequent slow recovery and evaluate the plausibility of potential drivers for the declines, as well as provide evidence against certain explanations that have been proposed in the past. Our systematic review shows that of seven possible hypotheses considered, at least three are credible and require additional information: (1) stochastic environmental events may have increased the snakes’ susceptibility to pathogens, (2) a resurgence in the abundance of top predators may have induced a localised change in trophic structure, and (3) an acute increase in local boat traffic may have had negative physical impacts. One or more of these factors, possibly acting in combination with as yet other unidentified factors, is the most plausible explanation for the precipitous decline in sea snake populations observed. Based on this position, we identify future research directions with a focus on addressing critical gaps in knowledge to inform and prioritise future management actions.

Modern Society and the Tsugaru Disciples

The final chapter illustrates how the Tsugaru group experienced modernity in the early Meiji period, including the transformation of their “country” into a prefecture within the modern nation of Imperial Japan. The astonishing growth of the Hirata academy followed by its precipitous decline reflect failed attempts to make Shinto and kokugaku the central ideology of the Meiji state, which increasingly adopted Western thought and institutions for modernizing society. The chapter illustrates the Shinto priests' struggles to implement the state directive for the Separation of Shinto and Buddhism and to preserve a “pure” Shinto. Following Tsuruya Ariyo's death in 1871, the chapter introduces Shimozawa Yasumi (1838–96), who memorialized the legacy of the Tsugaru family and domain through commissioned histories and poetry collections. Ultimately, it looks at Hirao Rosen's life in the Imperial nation of Japan ruled by the monarch, a period beyond what the kokugaku scholars had envisioned.