A century of canopy kelp persistence and recovery in the Gulf of Alaska

BACKGROUND AND AIMS

Coastal Alaska contains vast kelp habitat that supports diverse marine and human communities. Over the past century, the North Pacific Ocean has undergone oceanographic and ecological regime shifts that have the potential to influence the structure and function of kelp ecosystems strongly. However, the remoteness and complexity of the glacially carved region precludes the regular monitoring efforts that would be necessary to detect such changes.

METHODS

To begin to fill this critical knowledge gap, we drew upon historical and modern surveys to analyse the change in spatial coverage and species composition of canopy kelp between two time points (1913 and the early 2000s to 2010s). We also incorporated decadal surveys on sea otter range expansion following complete extirpation and reintroduction to assess the influence of sea otter recovery on the spatial extent of canopy kelp.

KEY RESULTS

We found increases in the spatial extent of canopy kelp throughout the Gulf of Alaska where there was coverage from both surveys. Kelp in Southcentral Alaska showed extensive recovery after the catastrophic Novarupta volcano. Kelp in Southeast Alaska showed persistence and spatial increase that closely matched increases in the range of sea otters. Observations of thermally tolerant kelp species increased more than observations of cold-adapted species between the two surveys.

CONCLUSIONS

Contrary to trends observed at lower latitudes, the kelp forests that ring the Gulf of Alaska have been remarkably stable and even increased in the past century, despite oceanographic and ecosystem changes. To improve monitoring, we propose identification of sentinel kelp beds for regular monitoring to detect changes to these iconic and foundational canopy kelp species more readily.

An Autobiographical Case Series of Familial Post Ambulatory Swollen Hands (POTASH): Hand Swelling in a Man and His Sister While Participating in a Half Marathon

Post ambulatory swollen hands (POTASH) is an acquired condition characterized by swelling of the hands, thumbs, and fingers following either walking, hiking, or running; no other body sites are swollen. The asymptomatic hand swelling begins in adulthood and recurs after adequate ambulation. A distinctive feature of POTASH that is often present is a positive fist sign demonstrated by the inability of the affected person to clench their fingers into the palm and form a fist. POTASH usually resolves spontaneously within a few hours after stopping ambulation; however, less frequently, it can persist for one or two days. The pathogenesis of POTASH has not been determined. In this case report, POTASH is described in an adult man and his sister. Neither the man's parents nor two of his other younger sisters had POTASH. However, the man's wife also develops POTASH with prolonged exercise; none of the three biological adult children of the man and his wife had POTASH. Therefore, based on these observations, the possibility that POTASH may have an autosomal recessive mode of inheritance and/or may be sporadic is suggested.

Microbiome convergence and deterministic community assembly along successional biocrust gradients on potash salt heaps

Potash mining, typically performed for agricultural fertilizer production, can create piles of residual salt waste that are ecologically detrimental and difficult to revegetate. Biological soil crusts (biocrusts) have been found growing on and around these heaps, suggesting resilience to the hypersaline environment. We set out to understand the community dynamics of biocrust formation by examining two succesionary salinity gradients at historical mining sites using a high throughput amplicon sequencing. Bare heaps were distinct, with little overlap between sites, and were characterized by high salinity, low nutrient availability, and specialized, low diversity microbial communities, dominated by Halobacteria, Chloroflexia, and Deinococci. 'Initial' stages of biocrust development were dominated by site-specific Cyanobacteria, with significant overlap between sites. Established biocrusts were the most diverse, with large proportions of Alphaproteobacteria, Anaerolineae, and Planctomycetacia. Along the salinity gradient at both sites, salinity decreased, pH decreased, and nutrients and Chlorophyll a increased. Microbiomes between sites converged during succession and community assembly process analysis revealed biocrusts at both sites were dominated by deterministic, niche-based processes; indicating a high degree of phylogenetic turnover. We posit early cyanobacterial colonization is essential for biocrust initiation, and facilitates later establishment of plant and other higher-level biota.

Crystallization of metastable monoclinic carnallite, KCl·MgCl2·6H2O: missing structural link in the carnallite family

During evaporation of natural and synthetic K-Mg-Cl brines, the formation of almost square plate-like crystals of potassium carnallite (potassium chloride magnesium dichloride hexahydrate) was observed. A single-crystal structure analysis revealed a monoclinic cell [a = 9.251 (2), b = 9.516 (2), c = 13.217 (4) Å, β = 90.06 (2)° and space group C2/c]. The structure is isomorphous with other carnallite-type compounds, such as NH4Cl·MgCl2·6H2O. Until now, natural and synthetic carnallite, KCl·MgCl2·6H2O, was only known in its orthorhombic form [a = 16.0780 (3), b = 22.3850 (5), c = 9.5422 (2) Å and space group Pnna].

Evaluation of Fertilizer Potential of Different K Compounds Prepared Utilizing Sea Bittern as Feed Stock

Aim: Many countries import potassic fertilizers due to dearth of K-mineral deposits. Therefore processes to obtain K-nutrient sources from sea bittern were developed by our Institute. The present investigation evaluated the fertilizer potential of three different sea bittern-derived (SBD) potassium forms developed viz., potassium schoenite, potassium nitrate and potassium ammonium sulfate on maize productivity in two cropping seasons. Methods: The pot and field experiments consisted of four treatments, wherein the three K forms were applied at the recommended rate of 40 kg K2O ha-1 and were compared with commercially used sulfate of potash. The effect of these fertilizers on different parameters of plant and soil were evaluated. Results: The application of SBD-potassic fertilizers led to enhancement in growth, productivity and quality of maize which related well with higher photosynthesis, nutrient uptake and soil quality parameters. On an average all the three forms of sea bittern-derived potash enhanced yield of maize over control by 22.3 and 23.8%, respectively, in pot and field trials. The best performance was under SBD-KNO3, which also recorded the highest benefit: cost ratio of 1.76. Conclusion: The K-fertilizers derived from sea-bittern-a waste product of salt industry-can thus be economically used to improve crop production sustainably.