Community collaboration and climate change research in the Canadian Arctic

Research on climate change impacts, vulnerability and adaptation, particularly projects aiming to contribute to practical adaptation initiatives, requires active involvement and collaboration with community members and local, regional and national organizations that use this research for policy-making. Arctic communities are already experiencing and adapting to environmental and socio-cultural changes, and researchers have a practical and ethical responsibility to engage with communities that are the focus of the research. This paper draws on the experiences of researchers working with communities across the Canadian Arctic, together with the expertise of Inuit organizations, Northern research institutes and community partners, to outline key considerations for effectively engaging Arctic communities in collaborative research. These considerations include: initiating early and ongoing communication with communities, and regional and national contacts; involving communities in research design and development; facilitating opportunities for local employment; and disseminating research findings. Examples of each consideration are drawn from climate change research conducted with communities in the Canadian Arctic.     

Fostering sustainable tribal economies in a time of climate change

In this article, we explore how Māori tribal organisations are responding to calls by other Indigenous peoples to become more sustainable in a time of climate change. From a close examination of tribal Environmental Management Plans, we move to a specific case study in the Bay of Plenty area, Ngāti Kea/Ngāti Tuara. Ultimately, we suggest that many tribal organisations are seeking to respond to climate change and transition to becoming producers of their own food and energy needs, and are often articulating these responses in relation to specific local resources and contexts.     

A semi-empirical wind set-up forecasting model for Lake Champlain

The precision of Lake Champlain's water level estimation is a key component in the flood forecasting process for the Richelieu River. Hydrological models do not typically take into consideration the effects of the wind on the water level (also known as the wind set-up). The objective of this study is to create an empirical wind set-up forecast model for Lake Champlain during high wind events. The proposed model uses wind speed and direction across the Lake, as well as wind gusts as inputs. The model is calibrated to a subset of observations and evaluated on an independent sample, considering four wind speed bins. It is tested and compared to a variant of the Zuider Zee equation on 20 wind set-up events that occurred between 2017 and 2019 using hindcast data from five different numerical weather prediction systems (GDPS, RDPS, HRDPS, NOAA and ECMWF). A quantile mapping-based forecast calibration scheme is implemented for each of the forecast products to correct their biases. Results show that events are successfully predicted by the proposed model at least 72 h in advance. These results are better than the other comparative models found in the literature and tested herein. Overall, significant improvements are obtained by including wind speed and wind gusts from different weather stations.     

A detailed analysis of the February 1996 aftershock sequence in the eastern Pyrenees, France

Following the 1996 February 18 M _L = 5.2 earthquake in the Agly massif in the eastern French Pyrenees, we installed a temporary network of seismometers around the epicentre. In this paper, we analyse 336 well-located aftershocks recorded from February 19 to February 23 by 18 temporary stations and two permanent stations located less than 35  km from the epicentre. Most aftershocks have been located with an accuracy better than 1.5  km in both horizontal and vertical positions. Their spatial distribution suggests the reactivation of a known fault system. We determined 39 fault-plane solutions using P -wave first motions. Despite their diversity, the focal mechanisms yield an E–W subhorizontal T-axis. We also determined fault-plane solutions and principal stress axes using the method developed by Rivera & Cisternas (1990 ) for the 15 best-recorded events. We obtain a pure-shear-rupture tectonic regime under N–S subhorizontal compression and E–W subhorizontal extension. These principal stress axes, which explain the focal mechanisms for at least 75 per cent of the 39 aftershocks, are different from the axes deduced from the main shock. The post-earthquake stress field caused by the main-shock rupture, modelled as sinistral strike slip on three vertical fault segments, is computed for various orientations and magnitudes of the regional stress field, assumed to be horizontal. The aftershock distribution is best explained for a compressive stress field oriented N30°E. Most aftershocks concentrate where the Coulomb failure stress change increases by more than 0.2  MPa. The diversity of aftershock focal mechanisms, poorly explained by this model, may reflect the great diversity in the orientations of pre-existing fractures in the Agly massif.     

Chemical defenses against generalist fish predators and fouling organisms in two invasive ahermatypic corals in the genus Tubastraea

The introduction of exotic marine species has caused considerable economic and ecological damage around the world. Some of these species possess adaptations such as secondary metabolites which facilitate their successful invasion into new areas. In this study we tested two hypotheses: (i) crude extracts produced by two invasive hard corals Tubastraea coccinea and Tubastraea tagusensis, introduced to the southwest Atlantic, inhibit predation by generalist fish; (ii) substances found in the crude extracts of both species reduce or enhance the settlement of other organisms. In an in situ palatability bioassay the extract of T. tagusensis reduced predation by generalist fish. The extracts of both species of coral showed species‐specific effects on fouling organisms in in situ gel plate bioassays. Control and extract plates had similar total cover, although plates with extracts had significantly fewer Cladophora sp., and Lithophyllum sp. was only detected on control gels. In contrast, a hydrozoan was only found on plates with extracts and overall community ordination demonstrated clear differences in the fouling communities between treatments. These results demonstrate that both coral species have chemical substances which can bring about a negative interaction with potential fish predators and competitors such as algal and invertebrate foulers and the advantage gained could explain their success in invading new regions to the detriment of local fauna and flora.     

Pathogens in Water: Value and Limits of Correlation with Microbial Indicators

This article discusses the value and limitations of using microbial indicators to predict occurrence of enteric pathogens in water. Raw or treated sewage is a primary source of fecal contamination of the receiving surface water or groundwater; hence, understanding the relationship between pathogens and indicators in sewage is an important step in understanding the correlation in receiving waters. This article presents three different datasets representing different concentrations of pathogens and microbial indicators: sewage containing high concentrations of pathogens and indicators, surface water with variable concentrations, and groundwater with low concentrations. In sewage, even with very high levels of microorganisms, no mathematical correlation can predict the type or concentration of any pathogen. After discharge in the environment, direct correlation becomes biologically improbable as dilution, transport, and different inactivation rates occur in various environments. In surface waters, advanced statistical methods such as logistic regression have provided some level of predictability of the occurrence of pathogens but not specific counts. In groundwater, the continuous absence of indicators indicates an improbable occurrence of pathogen. In contrast, when these indicators are detected, pathogen occurrence probability increases significantly. In groundwater, given the nature and dissemination pattern of pathogenic microorganisms, a direct correlation with fecal microbial indicators is not observed and should not be expected. However, the indicators are still useful as a measure of risk. In summary, many pathogens of public health importance do not behave like fecal microbial indicators, and there is still no absolute indicator of their presence, only a probability of their co‐occurrence.     

Giant palaeotsunami in Kiribati: Converging evidence from geology and oral history

For tsunami science within Oceania, the vast Central and Western Pacific (CEWEP) is an anomalous region because of the scarcity of historical tsunami observations and the complete absence of dated palaeotsunami evidence. This paper therefore records the first dated high-magnitude palaeotsunami event within the CEWEP region. A combination of both geological data and oral history is provided for a palaeotsunami that struck remote Makin island, northernmost of the Gilbert Islands in Kiribati, toward the end of the 16th century. A previously undocumented oral tradition of giant waves is well known to the people of Makin. Narration of this legend by the Wiin te Maneaba, traditional storyteller on Makin, provided important details supporting a tsunami hypothesis. The legend preserves credible information surrounding the giant-wave origin of Rebua and Tokia, two prominent subaerial megaclasts of blade and block geometry that were transported 80–130 m shorewards from the reef-edge source and deposited in sideways and inverted orientations. From available hydrodynamic flow transport equations, minimum flow velocities of 7.3–16.3 m s⁻¹ were generated, depending on whether the reefblocks were rotated or lifted onto the reef platform. The youngest U-Th age-dates for fossil corals retrieved from the reefblocks give a maximum age for the palaeotsunami of circa AD 1576. Several far-field Pacific Rim and regional possibilities exist for tsunamigenesis. These include subduction-zone seismicity and catastrophic volcanic eruption, both of which have been linked to earlier (late 15th century) palaeotsunami events recorded elsewhere in the Pacific Islands. However, the available evidence here suggests that the ~AD 1576 Makin palaeotsunami was more likely to have been locally generated by tsunamigenic offshore submarine slope failure close to Makin's western reef, associated with the giant arcuate bight structure that characterizes the northern rim of Butaritari atoll.     

Agrobiodiversity and Shade Coffee Smallholder Livelihoods: A Review and Synthesis of Ten Years of Research in Central America

We used households as the primary unit of analysis to synthesize agrobiodiversity research in small-scale coffee farms and cooperatives of Nicaragua and El Salvador. Surveys, focus groups, and plant inventories were used to analyze agrobiodiversity and its contribution to livelihoods. Households managed high levels of agrobiodiversity, including 100 shade tree and epiphyte species, food crops, and medicinals. Small farms contained higher levels of agrobiodiversity than larger, collectively managed cooperatives. Households benefited from agrobiodiversity through consumption and sales. To better support agrobiodiversity conservation, our analysis calls for a hybrid approach integrating bottom-up initiatives with the resources from top-down projects.