Michael Stekoll, Ph.D. is Professor of Chemistry and Biochemistry, Emeritus

Recent Submissions

  • High-latitude kelps and future oceans: A review of multiple stressor impacts in a changing world

    Farrugia Drakard, Veronica; Hollarsmith, Jordan; Stekoll, Michael (John Wiley & Sons, Inc., 2023-07-04)
    Kelp forests worldwide are threatened by both climate change and localized anthropogenic impacts. Species with cold-temperate, subpolar, or polar distributions are projected to experience range contractions over the coming decades, which may be exacerbated by climatic events such as marine heatwaves and increased freshwater and sediment input from rapidly contracting glaciers. The northeast Pacific has an extensive history of harvesting and cultivating kelps for subsistence, commercial, and other uses, and, therefore, declines in kelp abundance and distributional shifts will have significant impacts on this region. Gaps in our understanding of how cold-temperate kelp species respond to climate stressors have limited our ability to forecast the status of kelp forests in future oceans, which hampers conservation and management efforts. Here, we conducted a structured literature review to provide a synthesis of the impacts of multiple climate-related stressors on kelp forests in the northeast Pacific, assess existing knowledge gaps, and suggest potential research priorities. We chose to focus on temperature, salinity, sediment load, and light as the stressors most likely to vary and impact kelps as climate change progresses. Our results revealed biases in the existing literature toward studies investigating the impacts of temperature, or temperature in combination with light. Other stressors, particularly salinity and sediment load, have received much less focus despite rapidly changing conditions in high-latitude regions. Furthermore, multiple stressor studies appear to focus on kelp sporophytes, and it is necessary that we improve our understanding of how kelp microstages will be affected by stressor combinations. Finally, studies that investigate the potential of experimental transplantation or selective cultivation of genotypes resilient to environmental changes are lacking and would be useful for the conservation of wild populations and the seaweed aquaculture industry.
  • Conditions for staggering and delaying outplantings of the kelps Saccharina latissima and Alaria marginata for mariculture

    Raymond, Amy E. T.; Stekoll, Michael S. (Wiley, 2021-08-02)
    We describe a method for production of kelp using meiospore seeding creating flexibility for extended storage time prior to outplanting. One bottleneck to expansion of the kelp farming industry is the lack of flexibility in timing of seeded twine production, which is dependent on the fertility of wild sporophytes. We tested methods to slow gametophyte growth and reproduction of early life stages by manipulating temperature of the kelp Saccharina latissima. Reducing temperature from 12 C to 4 C reduced gametophyte size, sporophyte size, egg production, and sporophyte production and subsequently was the best candidate condition for storage experiments of seeded twine. Next, we examined how storage of Alaria marginata and S. latissima seeded twine at 4 C under differing nutrient concentrations affected the viability of sporelings after being moved into optimal growth conditions. Seeded twine storage at 4 C with no alteration to culturing media showed no negative effects in sporophyte density and sporophyte length for both species. This method for seeded twine storage, “cold banking,” allowed seeded twine storage for at least an additional 36 days compared to standard methods, with a total of 56 days spent in the hatchery providing opportunity for outplanting timing and staggering to enhance aquaculture efficiency.