Perceived Challenges to Tribally Led Shellfish Toxin Testing in Southeast Alaska: Findings From Key Informant Interviews.

Shellfish harvesting is central to coastal Alaska Native ways of life, and tribes in Southeast Alaska are committed to preserving sustainable and safe access to subsistence foods. However, consumption of non-commercially harvested shellfish puts Alaska Native communities at elevated risk of exposure to shellfish toxins. To address a lack of state or federal toxin testing for subsistence and recreational harvesting, tribes across Southeast Alaska have formed their own toxin testing and ocean monitoring program. In this study, we interviewed environmental managers responsible for tribes' testing and others with shellfish toxin expertise to report on perceptions of barriers to tribally led testing in Southeast Alaska. Tribal staff identified 40 prospective key informants to interview, including all environmental managers responsible for shellfish toxin testing at subsistence sites in Southeast Alaska. All 40 individuals were invited to participate in an interview and 27 individuals were interviewed. The most frequently discussed barriers to shellfish toxin testing in Southeast Alaska relate to logistical and staffing difficulties associated with communities' remote locations, inconsistent and inadequate funding and funding structures that increase staff burdens, risk communication challenges related to conveying exposure risks while supporting subsistence harvesting, and implications of climate change-related shifts in toxin exposures for risk perception and risk communication. Participants stressed the social origins of perceived barriers. Disinvestment may create and sustain barriers and be most severely felt in Native communities and remote places. Climate change impacts may interact with social and cultural factors to further complicate risk management.

Random forest classification to determine environmental drivers and forecast paralytic shellfish toxins in Southeast Alaska with high temporal resolution.

Paralytic shellfish poison toxins (PSTs) produced by the dinoflagellate in the genus Alexandrium are a threat to human health and subsistence lifestyles in Southeast Alaska. It is important to understand the drivers of Alexandrium blooms to inform shellfish management and aquaculture, as well as to predict trends of PST in a changing climate. In this study, we aggregate environmental data sets from multiple agencies and tribal partners to model and predict concentrations of PSTs in Southeast Alaska from 2016 to 2019. We used daily PST concentrations interpolated from regularly sampled blue mussels (Mytilus trossulus) analyzed for total PSTs using a receptor binding assay. We then created random forest models to classify shellfish above and below a threshold of toxicity (80 µg 100 g-1) and used two methods to determine variable importance. We obtained a multivariate model with key variables being sea surface temperature, salinity, freshwater discharge, and air temperature. We then used a similar model trained using lagged environmental variables to hindcast out-of-sample (OOS) shellfish toxicities during April-October in 2017, 2018, and 2019. Hindcast OOS accuracies were low (37-50%); however, we found forecasting using environmental variables may be useful in predicting the timing of early summer blooms. This study reinforces the efficacy of machine learning to determine important drivers of harmful algal blooms, although more complex models incorporating other parameters such as toxicokinetics are likely needed for accurate regional forecasts.

The Southeast Alaska Tribal Ocean Research (SEATOR) Partnership: Addressing Data Gaps in Harmful Algal Bloom Monitoring and Shellfish Safety in Southeast Alaska.

Many communities in Southeast Alaska harvest shellfish such as mussels and clams as an important part of a subsistence or traditional diet. Harmful algal blooms (HABs) of phytoplankton such as Alexandrium spp. produce toxins that can accumulate in shellfish tissues to concentrations that can pose a hazard for human health. Since 2013, several tribal governments and communities have pooled resources to form the Southeast Alaska Tribal Ocean Research (SEATOR) network, with the goal of minimizing risks to seafood harvest and enhancing food security. SEATOR monitors toxin concentrations in shellfish and collects and consolidates data on environmental variables that may be important predictors of toxin levels such as sea surface temperature and salinity. Data from SEATOR are publicly available and are encouraged to be used for the development and testing of predictive algorithms that could improve seafood risk assessment in Southeast Alaska. To date, more than 1700 shellfish samples have been analyzed for paralytic shellfish toxins (PSTs) in more than 20 locations, with potentially lethal concentrations observed in blue mussels (Mytilus trossulus) and butter clams (Saxidomus gigantea). Concentrations of PSTs exhibit seasonality in some species, and observations of Alexandrium are correlated to sea surface temperature and salinity; however, concentrations above the threshold of concern have been found in all months, and substantial variation in concentrations of PSTs remain unexplained.

Early phonological awareness and reading skills in children with Down syndrome.

Increasingly, children with Down syndrome receive literacy instruction with the expectation of acquiring functional reading skills. Unfortunately, little is known about the processes underlying literacy skills in this special population. Phonological awareness contributes to literacy development in typically developing children, however, there is inconclusive evidence about these skills in younger children with Down syndrome. 9 children with Down syndrome (5.6-8.10 years) participated in this investigation. Due to the paucity of standardised phonological awareness measures for children with special needs, in particular children with Down syndrome, a variety of tasks were adapted from the literature. The assessment battery examined the skills of phonological awareness, literacy, speech production, expressive language, hearing acuity, speech perception, and auditory-visual memory. The results suggest that children with Down syndrome are at risks for reading acquisition difficulties due to reduced phonological awareness skills. These deficits are in addition to delays caused by reduced cognitive skills. Only one of the participants was able to demonstrate rhyme awareness, which may have been due to task effects. Written word recognition ability was correlated with tests of phonemic awareness, and error analysis of the spelling and non-word reading tasks suggested grapheme-phoneme connections deficits. Further research is needed to determine the best methods of assessment and intervention for phonological awareness in children with Down syndrome.

Training phonological awareness skills in children with Down syndrome.

Increasingly, children with Down syndrome receive literacy instruction based on a phonological awareness philosophy with the expectation of acquiring functional reading skills. Previous research demonstrates that a phonological awareness based reading programme delivers excellent results in terms of literacy acquisition and improvements in speech production for children with speech and language delays. Unfortunately, little research exists to support the effectiveness of this approach for children with Down syndrome. The current research study examined using a phonological awareness based intervention programme with three children with Down syndrome (aged 7;2, 8;4, and 8;10). A multiple baseline across behaviours design was selected. The intervention programme focused on the key skills of alliteration detection, phoneme isolation, spelling of orthographically regular words and rhyme detection. Two tasks (comprehension of passive structures and spatial structures) were selected as control behaviours. Phoneme segmentation and speech intelligibility were selected to investigate generalisation of intervention targets to other related skill areas. The results indicated that the participants improved the phonological awareness skills targeted in the intervention programme. Unfortunately, no generalisation to other areas of phonological awareness was noted. In summary, the results indicate that children with Down syndrome can benefit from a phonological awareness based approach to literacy.