Shell-bearing mollusks of the order Cephalaspidea (Gastropoda: Heterobranchia) of the Kara Sea: fauna and ecology

The survey of shell-bearing heterobranchs of the order Cephalaspidea of the Kara Sea has been done based on unpublished and literature data. The studied material includes that collected during expeditions aboard R/V Professor Multanovskiy in August–September 2019 and R/V Dalnie Zelentsy in August 2012. Additionally, the material of collections of the Zoological Institute of the Russian Academy of Sciences (Saint Petersburg) has been studied. The fauna of heterobranch molluscs of the order Cephalaspidea in the Kara Sea includes 18 described and 1 undescribed species that belong to 10 genera and 6 families. It has been specified that the type locality of Retusa semen Reeve, 1855 (Port Refuge) is located at Port Refuge National Historic Site of Canada, Devon Island, Nunavut, not in the Kara Sea. Retusa semen is considered here as species inquirenda because of the brief original description, significant differences in drawings of the shell of this species made by different authors, and the absence of type specimens. The presence of Diaphana minuta Brown, 1827, Laona quadrata (Wood, 1839), Philine sinuata Stimpson, 1851 and Retusa semen in the Kara Sea needs confirmation. Species numbers of heterobranch molluscs of the order Cephalaspidea decrease from the Barents Sea (21) through the Kara Sea (19) to the Laptev Sea (15) because of the decreasing proportion of boreal-arctic species. Among cephalaspids of the Kara Sea, the highest average abundance (individuals/m2) was observed for Cylichnoides densistriatus (Leche, 1878), and the highest average biomass for Cylichna corticata (Møller, 1842). The proportion of live individuals in the populations does not exceed 18% in late August – early September. The taxonomic structure of the cephalaspid fauna of the Kara Sea has been studied based exclusively on morphological characters. Further study of the fauna is needed based on molecular analyses of the material fixed in 96˚ alcohol.

Data Analysis for Optimization of Mars Terraforming: A GIS Framework

This study has developed a GIS framework that uses spatial environmental and climate data to better understand areas on Earth that share the most environmental similarities to Mars. The purpose of developing this framework is to determine which vegetation is most likely to survive in closed bioregenerative life support systems on Mars, using as many in-situ materials and environmental elements as possible. Using remotely sensed climate data, digital elevation models, and vegetation occurrence data sourced from the Global Biodiversity Information Facility, three Mars-like study areas on Earth were analysed (the Antarctic Peninsula, Ellesmere Island, and Devon Island). This study found that plants that are part of the Bryophyte and Tracheophyta phyla are worthy of further research in regard to possible vegetation candidates that could be brought to Mars. In addition, the most promising candidate of the entire study is the genus Poa, which is found in the phylum Tracheophyta.

Data Analysis for Optimization of Mars Terraforming: A GIS Framework

This study has developed a GIS framework that uses spatial environmental and climate data to better understand areas on Earth that share the most environmental similarities to Mars. The purpose of developing this framework is to determine which vegetation is most likely to survive in closed bioregenerative life support systems on Mars, using as many in-situ materials and environmental elements as possible. Using remotely sensed climate data, digital elevation models, and vegetation occurrence data sourced from the Global Biodiversity Information Facility, three Mars-like study areas on Earth were analysed (the Antarctic Peninsula, Ellesmere Island, and Devon Island). This study found that plants that are part of the Bryophyte and Tracheophyta phyla are worthy of further research in regard to possible vegetation candidates that could be brought to Mars. In addition, the most promising candidate of the entire study is the genus Poa, which is found in the phylum Tracheophyta.

An ~1100 yr record of human and seabird occupation in the High Arctic inferred from pond sediments

Seabirds in the Canadian Arctic congregate in large colonies, producing oases of biological productivity and diversity in coastal regions. Here, we examined sterols, stanols, and stable isotopes (δ15N and δ13C) in three 14C-dated pond sediment cores near a large seabird colony and archaeological site on Devon Island (Nunavut, Canada), showing historical occupation by the seabirds and an ancient human (Thule or Norse) settlement over an ~1100 yr time period. Coprostanol in the sediment records captures the presence of humans at ca. 1150 CE, followed by their abandonment of the site by ca. 1300 CE. Increased seabird presence at this site after ca.1200 CE is indicated by increases in δ15N and cholesterol/sitosterol. Seabird population expansion is observed after ca. 1600 CE in δ15N and cholesterol/sitosterol profiles, coinciding with European whaling activities that expanded in the seventeenth through nineteenth centuries. Our study provides insights into human and seabird occupation in the High Arctic to inform archaeological and conservation efforts.

Robert McCormick and the circumstances of his Arctic fossil collection, 1852–1853

The Royal Navy surgeon Robert McCormick (1800–1890) took part in three mid-nineteenth century British Polar expeditions, two to the Arctic and one to the Antarctic. Of the two Arctic voyages, the first was to Spitsbergen (in today's Svalbard) in 1827; the second from 1852 to 1853, was one of the expeditions dispatched to search for the missing ships commanded by Sir John Franklin that had set out in 1845 to navigate a “Northwest Passage” through the islands of the Canadian Arctic. The Svalbard expedition was formative in developing McCormick's interest in the Polar regions, with the likely highlight of his career being his subsequent participation in the Antarctic expedition of 1839–1843 led by James Clark Ross. Throughout these expeditions, McCormick collected natural history specimens, principally in the fields of ornithology and geology. Many of the geological specimens he retained in a personal collection which passed to what is now the Natural History Museum, London, on his death in 1890. This collection includes rock specimens from Svalbard and Baffin Bay, and a substantial number of Silurian fossils (mostly brachiopods) from Beechey Island and Devon Island in the Canadian Arctic. The fossil collection was the largest of several assembled during the successive expeditions sent out in search of Franklin, but is one of those that has received no subsequent attention. That omission was largely due to McCormick's own scientific shortcomings and persisted despite his determined efforts to promote himself as a serious scientific naturalist and Arctic authority.

Melt-water formed dark streaks on slopes of Haughton crater as possible Mars analogues

Haughton crater in the Canadian Arctic has been extensively used as a Mars (and lunar) analogue over the past 20 years. Here we report on small scale, dark, semi-seasonal slope streaks formed by melt water flowing down the crater walls that we observed during the Mars Society-sponsored M160 expedition to the F-MARS facility on the NW rim of the crater. The streaks are formed by biofilms colonizing snow melt flowing from semi-permanent snow patches in Haughton crater on Devon Island and elsewhere in the Canadian Arctic. These features superficially resemble the dark slope streaks and recurring slope lineae (RSL) observed on Mars and may serve as analogues for wet models for their formation and a contrast with dry formation models. Their significance to astrobiology and planetary science is three-fold: (1) as examples of dark recurring streaks known to be associated with water they provide a benchmark to compare with Martian slope streaks and RSL. (2) The melt streaks may have potential as astrobiological analogues for wet models of slope streaks and RSL. (3) They are natural laboratories to study planetary protection issues associated with robotic and astronaut exploration of potential water-related slope features on Mars.