Range wide genetic differentiation in the bull kelp Nereocystis luetkeana with a seascape genetic focus on the Salish Sea

Gierke, Lily; Coelho, Nelson C.; Khangaonkar, Tarang; Mumford, Tom; Alberto, Filipe

doi:10.3389/fmars.2023.1275905

Cited by 4 publications

(2 citation statements)

References 144 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Various ecological nuances dictate the phenology of Pyropia nereocystis. Hosts enable P. nereocystis haploid success by influencing abundance, persistence, and, consequentially, genetic diversity within and among populations (Saunders, 2014; see Gierke et al, 2023). Although these effects occur on an individual epiphyte and host scale, host biogeography stretches over a diverse abiotic and biotic range, which influences epiphyte phenology on scales ranging from site to region (tens to hundreds of kilometers).…”

Section: Discussionmentioning

confidence: 99%

Syncopation and synchrony: Phenological dynamics of Pyropia nereocystis (Bangiophyceae) in central California

Gossard

2024

Journal of Phycology

View full text Add to dashboard Cite

Pyropia nereocystis is an annual northeastern Pacific‐bladed bangialean species whose macroscopic stage epiphytized the annual canopy forming bull kelp Nereocystis luetkeana. I examined three in situ facets of these epiphyte‐host dynamics in the central California region: (1) spatial and temporal variation in the presence of P. nereocystis epiphytes as a function of host density, (2) the relationship between individual host morphology and epiphytic P. nereocystis biomass, and (3) the ecophysiological growth ramifications for subtidal transplants of both life stages of P. nereocystis. Swath canopy surveys and whole host collections were conducted at five sites between November 2017 and February 2019. Additionally, transplants of P. nereocystis gametophytes and sporophytes were conducted across multiple subtidal depths. I observed temporal changes in the proportions of hosts epiphytized by P. nereocystis, with differences in seasonal persistence of P. nereocystis among sites and between years. Biomass of P. nereocystis was positively correlated with individual host stipe length, stipe surface area, and the primary principal component (PC) of stipe morphometrics denoted by principal component analysis (PCA). Gametogenesis in P. nereocystis epiphytes was spatially heterogeneous and limited for the 2018–2019 cohort due to comprehensive removal of hosts by the February 2019 sampling period. Transplants of P. nereocystis gametophytes yielded similar growth responses among depths, and sporophyte (conchocelis) transplant areal growth was positively correlated with transplant depth. These findings detail spatiotemporal complexity and multi‐scale (individual, site, and whole region) phenological nuances for central Californian P. nereocystis epiphytes.

show abstract

Section: Discussionmentioning

confidence: 99%

Syncopation and synchrony: Phenological dynamics of Pyropia nereocystis (Bangiophyceae) in central California

Gossard

2024

Journal of Phycology

View full text Add to dashboard Cite

show abstract

“…Populations of Nereocystis luetkeana in the Salish Sea displayed differences in genetic diversity via microsatellite markers, and populations in South Puget Sound displayed the lowest allelic richness (Gierke, 2019). Populations with low genetic diversity can be more susceptible to marine heatwaves (Wernberg et al, 2018).…”

Section: Discussionmentioning

confidence: 99%

Effects of temperature and nutrients on microscopic stages of the bull kelp (Nereocystis luetkeana, Phaeophyceae)

Weigel

Small

Berry

et al. 2023

Journal of Phycology

View full text Add to dashboard Cite

Warming ocean temperatures have been linked to kelp forest declines worldwide, and elevated temperatures can act synergistically with other local stressors to exacerbate kelp loss. The bull kelp Nereocystis luetkeana is the primary canopy‐forming kelp species in the Salish Sea, where it is declining in areas with elevated summer water temperatures and low nutrient concentrations. To determine the interactive effects of these two stressors on microscopic stages of N. luetkeana, we cultured gametophytes and microscopic sporophytes from seven different Salish Sea populations across seven different temperatures (10–22°C) and two nitrogen concentrations. The thermal tolerance of microscopic gametophytes and sporophytes was similar across populations, and high temperatures were more stressful than low nitrogen levels. Additional nitrogen did not improve gametophyte or sporophyte survival at high temperatures. Gametophyte densities were highest between 10 and 16°C and declined sharply at 18°C, and temperatures of 20 and 22°C were lethal. The window for successful sporophyte production was narrower, peaking at 10–14°C. Across all populations, the warmest temperature at which sporophytes were produced was 16 or 18°C, but sporophyte densities were 78% lower at 16°C and 95% lower at 18°C compared to cooler temperatures. In the field, bottom temperatures revealed that the thermal limits of gametophyte growth (18°C) and sporophyte production (16–18°C) were reached during the summer at multiple sites. Prolonged exposure of bull kelp gametophytes to temperatures of 16°C and above could limit reproduction, and therefore recruitment, of adult kelp sporophytes.

show abstract

Bimodal spore release heights in the water column enhance local retention and population connectivity of bull kelp, Nereocystis luetkeana

Burnett,

Ricart,

Winquist

et al. 2024

Ecology and Evolution

View full text Add to dashboard Cite

Dispersal of reproductive propagules determines recruitment patterns and connectivity among populations and can influence how populations respond to major disturbance events. Dispersal distributions can depend on propagule release strategies. For instance, the bull kelp, Nereocystis luetkeana, can release propagules (spores) from two heights in the water column (“bimodal release”): at the water surface, directly from the reproductive tissues (sori) on the kelp's blades, and near the seafloor after the sori abscise and sink through the water column. N. luetkeana is a foundation species that occurs from central California to Alaska and is experiencing unprecedented levels of population declines near its southern range limit. We know little of the kelp's dispersal distributions, which could influence population recovery and restoration. Here, we quantify how bimodal spore release heights affect dispersal outcomes based on a numerical model specifically designed for N. luetkeana. The model incorporates oceanographic conditions typical of the species' coastal range and kelp biological traits. With bimodal release heights, 34% of spores are predicted to settle within 10 m of the parental alga and 60% are predicted to disperse beyond 100 m. As an annual species, bimodal release heights can facilitate the local regeneration of adults within a source kelp forest while also supporting connectivity among multiple forests within broader bull kelp metapopulations. To leverage this pattern of bimodal spore dispersal in bull kelp restoration management, directing resources toward strategically located focal populations that can seed other ones could amplify the scale of recovery.

show abstract

Range wide genetic differentiation in the bull kelp Nereocystis luetkeana with a seascape genetic focus on the Salish Sea

Cited by 4 publications

References 144 publications

Syncopation and synchrony: Phenological dynamics of Pyropia nereocystis (Bangiophyceae) in central California

Syncopation and synchrony: Phenological dynamics of Pyropia nereocystis (Bangiophyceae) in central California

Effects of temperature and nutrients on microscopic stages of the bull kelp (Nereocystis luetkeana, Phaeophyceae)

Bimodal spore release heights in the water column enhance local retention and population connectivity of bull kelp, Nereocystis luetkeana

Contact Info

Product

Resources

About