Seabed sediment composition is an important component of benthic habitat and there are many approaches for producing maps that convey sediment information to marine managers. Random Forest is a popular statistical method for thematic seabed sediment mapping using both categorical and quantitative supervised modelling approaches. This study compares the performance and qualities of these Random Forest approaches to predict the distribution of fine-grained sediments from grab samples as one component of a multi-model map of sediment classes in Frobisher Bay, Nunavut, Canada. The second component predicts the presence of coarse substrates from underwater video. Spatial and non-spatial cross-validations were conducted to evaluate the performance of categorical and quantitative Random Forest models and maps were compared to determine differences in predictions. While both approaches seemed highly accurate, the non-spatial cross-validation suggested greater accuracy using the categorical approach. Using a spatial cross-validation, there was little difference between approaches—both showed poor extrapolative performance. Spatial cross-validation methods also suggested evidence of overfitting in the coarse sediment model caused by the spatial dependence of transect samples. The quantitative modelling approach was able to predict rare and unsampled sediment classes but the flexibility of probabilistic predictions from the categorical approach allowed for tuning to maximize extrapolative performance. Results demonstrate that the apparent accuracies of these models failed to convey important differences between map predictions and that spatially explicit evaluation strategies may be necessary for evaluating extrapolative performance. Differentiating extrapolative from interpolative prediction can aid in selecting appropriate modelling methods.

Dispossession from social and ecological support systems is a major concern for many Indigenous communities. In response to community health challenges in these settings a number of initiatives such as youth mentorship programs have shown some value in enhancing adaptive capacity. The pilotGoing Off, Growing Strongprogram provides opportunities for at-risk youth to engage in community- and land-based activities and build relationships with positive adult role models in Nain, Nunatsiavut (Labrador, Canada). This paper offers an interpretive description drawing from autobiographical accounts of the development of this innovative program. A collaboratively developed conceptual framework, based on the literature, is used to present and explain program operator’s experiences and rationale for program development. The emergent goals ofGoing Off, Growing Strongare to strengthen individual youth and collective community resilience through intergenerational exchange of land, social, and cultural skills and knowledge by drawing on social supports, such as a community freezer and experienced harvesters. We found that the process of collaborating over time with multiple stakeholders in creating this conceptual framework was an important one for solidifying the goals ofGoing Off, Growing Strongand creating context-specific, meaningful evaluation outcomes to enable future measurement of impacts on the community.

Increased variability in weather and sea ice conditions due to climate change has led to high rates of injury, trauma, and death for Inuit travelling on the sea ice. Contributing to these high rates are the ongoing effects of colonial policies that diminish and disrupt the intergenerational transfer of sea ice Inuit Qaujimajatuqangit (IQ). Despite these challenges, place-based experiential IQ continues to be the most important information source for safe travel on the sea ice. This paper presents an Inuit-led, coproduced, cross-cultural research project in which Inuit youth documented and mobilized sea ice IQ in Mittimatalik (Pond Inlet), Nunavut for safe community sea ice travel. We outline the Inuit youth training to facilitate the terminology and participatory mapping workshops and to document this IQ. We also discuss the IQ that was most important to share, and the mapping and artistic methods used to mobilize this IQ into a booklet, maps, and posters. Inuktitut sea ice terms are the foundation to enable youth with the skills to learn about sea ice IQ with experienced hunters. IQ enables Inuit to interpret and synthesize information from weather forecasts, earth observations, and community-based monitoring to apply to local conditions. Seasonal IQ maps of safe and hazardous sea ice conditions provide travel planning information at spatial and temporal scales that supplemental information sources cannot address. The IQ products mobilize preparedness, situational awareness, navigation, and interpretation skills so Inuit youth can become more self-reliant, as access to technology is not always possible once out on the sea ice.

We argue that variable and complex post-glacial relative sea level (RSL) in Newfoundland is linked to (1) the uneven distribution around the coastline of late Maritime Archaic Indian (MAI) sites (5500–3200 bp) and (2) the apparent absence of early MAI sites (8000–5500 bp), despite their presence in nearby southern Labrador. Three post-glacial RSL histories are described for different regions of Newfoundland: continuous emergence (type A), initial emergence followed by submergence (type B) and continuous submergence (type C). In areas characterized by type B or C curves, where the lowstand is greater than 20m water depth, late MAI sites older than 3000 bp are today submerged. In all areas other than those characterized by a type A curve, early MAI sites would be under water. The Northern Peninsula is the only region of Newfoundland described by a type A curve. If early MAI did occupy Newfoundland, we predict where on the Northern Peninsula those sites would be found.

In the small city of St. John’s, NL (2020 population ~114,000), 100% of the soils of the pre-1926 properties exceeded the Canadian soil Pb standard, 140 mg/kg. The Pb was traced to high-Pb coal ash used for heating and disposed on the soils outside. Analytical instruments became available in the late 1960s and 1970s and were first used for blood Pb and clinical studies and repurposed for measuring environmental Pb. The environmental research part of this study compared four common soil Pb analysis methods on the same set (N = 96) of St. John’s soil samples. The methods: The US EPA method 3050B, portable X-ray fluorescence spectrometry (pXRF), The Chaney–Mielke leachate extraction (1 M nitric acid), and the relative bioaccessibility leaching procedure (US EPA method 1340). Correlation is not the same as agreement ℜ. There is strong agreement (Berry–Mielke’s Universal ℜ) among the four soil Pb analytical methods. Accordingly, precaution is normally advisable to protect children from the high-Pb garden soils and play areas. A public health reality check by Health Canada surveillance of St. John’s children (N = 257) noted remarkably low blood Pb. The low blood Pb of St. John’s’ children is contrary to the soil Pb results. Known urban processes causing the rise of environmental Pb and children’s Pb exposure includes particle size, aerosol emission by traffic congestion, and quantities of leaded petrol during the 20th century. Smaller cities had minor traffic congestion and limited combustion particles from leaded petrol. From the perspective of the 20th century era of urban Pb pollution, St. John’s, NL, children have blood Pb characteristics of a small city.