Development of invasive pink salmon (Oncorhynchus gorbuscha Walbaum) eggs in a large Barents Sea river.

The spawning and egg development of invasive pink salmon Oncorhynchus gorbuscha were investigated in the large River Teno in the Barents Sea area where they spawned for the first time on a large scale in 2021. The spawning period started in early August and egg development was rapid. All eggs were eyed by mid-September and the first juveniles hatched in late September. In early October most eggs had hatched. Degree-days in water temperature suggested that egg deposition had mostly taken place in early August. Early egg development is discussed in relation to possible consequences for survival.

Cascade processing of softwood bark with hot water extraction, pyrolysis and anaerobic digestion.

A process model based on hot water extraction (HWE), slow pyrolysis and anaerobic digestion (AD) were used for pine and spruce bark utilisation. First tannins (32 mg/g and 11.8 mg/g, respectively) and polyphenols were recovered via HWE. Then, the residue was pyrolysed to produce biochar (marketable quality), gas (energy source) and liquid fractions. The liquid fraction was further separated into aqueous acidic fraction and to tar fraction. Bark, extracted bark residue and acidic liquid fraction from pyrolysis were treated in AD to produce biomethane and digestate. The methane yields from pine and spruce bark and extracted bark residue were low (from 42 to 96 mLCH4/gVSadded) and showed only small differences. In conclusion, cascade processing can improve the performance of subsequent single processes and utilise biomass sources with higher efficiency. The best processing chain may vary in different cases and the overall energy balance of processing needs further research.