A magnified view of a finely branched scarlet red seaweed. The main axes have occasional enlarged branchlets that look like swollen hooks

For #phycologyfriday: The unusual fishhooks of Bonnemaisonia californica
#rhodophyta #algae #seaweed #intertidal #marinelife #redalgae #marinebiology #science

Halosaccion glandiforme at Whiffin Spit. This red algae fills with water, likely to prevent desiccation.

🦑 #PhycologyFriday #Intertidal #tidepools

Two large bladed kelps lying next to one another on an eelgrass bed. The left kelp is Saccharina latissima, with a narrower and lighter colored blade and stipe, while the right kelp is Hedophyllum nigripes, with a broad dark blade

A close up of the stipes of two large kelps. Saccharina on the top has a narrow rounded stipe, Hedophyllum nigripes on the bottom has a broad flattened stipe

Today for #phycologyfriday: two commonly confused PNW kelps next to each other, from the same site (Whiffin Spit, BC). Left is Saccharina latissima, right Hedophyllum nigripes.
#marinelife #intertidal #pnw #biology #marinebiology #science #kelp #seaweed

A colony of pink sponges on the bottom of a rock. The top of the rock is colonized by barnacles

Pretty barnacles and sponges

🦑 #intertidal

A very extreme and unusual presentation of pink-spot disease on a kelp spool

For this #PhycologyFriday I'm happy to share my ✨new paper✨ about #kelp disease -> rdcu.be/ets28

Pink-spot disease occurs in kelp nurseries across North America and Europe according to our survey and we identified a bacteria (Algicola sp.) as the likely causative agent.

🦑 #aquaculture

Brown, ball shaped seaweed with wrinkled surfaces grow in a grapelike cluster on a different species of finely branched seaweed in a rocky intertidal zone

Today for #phycologyfriday: Soranthera ulvoidea, a saccate brown alga that grows only on some species of red algae (in this case Odonthalia floccosa)
#marinelife #tidepools #algae #seaweed

Three unusual looking bull kelp that lack the usual pneumatocyst and stipe

Lab grown stipeless bull kelp to reduce tangling in tumble culture. Removal of the stipe before the internal cavity inflates results in the cut sealing over to form a "knot" instead of the usual pneumatocyst + stipe
#phycologyfriday #kelp #marinebiology #science #algae #seaweed

A mix of predominantly brown and red algae growing off a cobble bottom, with a submerged gumboot chiton in the middle

A gumboot chiton in a medley of seaweeds #phycologyfriday #intertidal #tidepool #marinelife

Part of figure 1 for the paper. There is a map of the field sites and an overview of the lab experiment. Field measurements were temperature and salinity. Lab was only salinity

My ✨new paper✨ looking at how low salinity and high temperatures alter the bacterial community of sugar #kelp was just published!

Lab and field results agree: the overall changes are small, but core taxa decrease under abiotic stress

onlinelibrary.wiley.com/doi/10.1111/...

#PhycologyFriday 🦑

A three tiered display of brown mugs featuring handles that look like bull kelp stipes and blades that wrap around the mug body

Honoured to have been able to make speaker gifts for the 2025 international seaweed symposium! #phycologyfriday #iss25 #pottery #ceramics #kelp

P1: Monthly macroalgal surveys reveal a diverse and dynamic community in an urban intertidal zone
P2: Effects of thermal stress on sorus formation in bull kelp Nereocystis luetkeana
P3: Kelps on demand: closed-system protocols for culturing large bull kelp sporophytes for research and restoration

Two hands holding an individual Laminaria ephemera kelp up for a photo. The kelp is small but a dark spore patch is already visible near the blade base. The holdfast is attached to a pebble which is being held. In the background, the lionsgate bridge is visible.

A very unexpected find: Laminaria ephemera at Stanley Park in a seaweed diversity survey quadrat! I'll be presenting on this project (and others) at #ISS25 - see comments for details.
#phycologyfriday

Dark brown kelp with light brown stipes on sand. The stipes are short and woody

Drift Lessoniopsis for #PhycologyFriday.

Lessoniopsis lives in very wave exposed areas. If you look closely at the stipes, you will find holes made by burrowing amphipods

🦑🧪🌊

Narrow golden brown blades of the kelp Laminaria ephemera hang from a rock mingled with young blades of other kelp species, filmy ulvoid green algae and various red algae

Blink and you miss it: the spring bloom of Laminaria ephemera, one of the shortest-lived and smallest kelps

#phycologyfriday #intertidal #marinelife #kelp #science

One of the few kelp species that can spread clonally through a rhizomatous holdfast

A dense cluster of brown kelp hangs from a half submerged rock. Long dark stipes rise from a hidden rhizomatous holdfast and terminate in straplike, translucent blades

A rarity in Canadian waters: Laminaria sinclairii at French Beach, BC.

#laminaria #phycologyfriday #kelp #seaweed #intertidal #marinelife #science #marinebiology #algae

For #PhycologyFriday, check out this gorgeous red algae (possibly Gloiocladia laciniata) that appears iridescent blue / purple underwater! Photo taken underwater ~6 m depth 🤿

Closeups of historical seaweed pressings from the University Herbarium in Berkeley for #PhycologyFriday

Several small bull kelp sprouting from the top of a dogwinkle (marine snail) shell

Today for #phycologyfriday: a couple of tiny bull kelp sprouting from the shell of a dogwinkle

#bullkelp #nereocystis #kelp #phycology #seaweed #algae #marinelife #intertidal #marinebiology #science #tidepool

Happy #PhycologyFriday #Seaweed #Art

Narrow blades of seaweed moving in the current. The blades are dark blood red with striking pale veins

Today for #phycologyfriday: the gorgeous Erythrophyllum delesserioides, found along exposed, wave-swept coasts of the PNW

#redalgae #erythrophyllum #phycology #marinelife #intertidal #marinebiology #seaweed #algae #science #botany

A microscopic view of a filamentous red alga called Antithamnionella spirographidis. The alga is a filament made of cylindrical cells, with a herringbone-like branching pattern and large, round and dark sporangia at the base of each branch

Antithamnionella spirographidis under a microscope. Collected at Stanley Park during a long term macroalgal survey by @siobhanschenk.bsky.social and I that was recently accepted as a paper cdnsciencepub.com/doi/abs/10.1...

#phycologyfriday #marinelife #intertidal #seaweed #marineecology #science

Close up of the holdfast. The algae are washed up on sand.

Some Codium setchellii on a drift Pterygophora californica holdfast for #PhycologyFriday

From the edge of the Pacific in BC, Canada...

I offer the compact but mighty 'Sea Palm', Postelsia palmaeformis, for this #PhycologyFriday.

"I will bend but I will not break"

Graphic of kelp genetics.

Giant kelp. In particular, kelp forests are declining in many parts of the northeast Pacific, practically right off my doorstep where we live close to Puget Sound [Salish Sea]. "Bemmels et al. sequenced the genomes of 429 bull kelp (Nereocystis luetkeana) and 211 giant kelp (Macrocystis sp.) from the coastlines of British Columbia and Washington." They found 'low effective population size was associated with low genetic diversity and high inbreeding coefficients (including increased selfing rates), with extreme variation in these genetic health indices among bull kelp populations but more moderate variation in giant kelp.' They found fewer deleterious variants than predicted, but suspect their loss was more likely due to genetic drift rather than purging. "The researchers predict (1) reduced within-population inbreeding depression in small populations, which may be associated with an observed shift toward increased selfing rate, and (2) hybrid vigor in crosses between small populations." These findings inform several possible strategies for optimal sourcing and crossing of populations for restoration + aquaculture. Kelp have keystone ecosystem functions, but also represent a potential source of both biofuel + agricultural amendments.

Curr. Biol. (2025) 10.1016/j.cub.2024.12.025  Kelp forests are integral + critical to aquatic ecosystems, but species such as giant kelp + bull kelp have experienced population bottlenecks in recent decades.

A purple sea urchin munching on some Hedophyllum sessile. The tide is out, so the urchin and kelp are out of the water.

A purple sea urchin munching on some Hedophyllum sessile for #PhycologyFriday . This was on Calvert Island.

#seaurchin #kelp 🦑

For #PhycologyFriday, here’s some Southern Sea Palm kelp (Eisenia arborea) and Giant Kelp (Macrocystis pyrifera sensu lato) from a swelly fun dive last December here in Huu-ay-aht territory, Barkley Sound, Vancouver Island

A small bull kelp with a very unusual morphology. The stipe is wrinkled and twisted, while the blades arise from the side of the oblong pneumatocyst instead of the top

Today for #phycologyfriday: a rather unusual bull kelp that popped up in a lab tumble culture

#bullkelp #nereocystis #kelp #seaweed #phycology #marinelife #intertidal #marinebiology #science #biology

A dark red ceramic bowl with unfinished carvings of the kelp Alaria on the sides

A new in progress #pottery project for #phycologyfriday: #Alaria marginata carved on a bowl

#kelp #seaweed #marineart #phycology #sculpture #carving #ceramics #clay

@varoon-supratya.bsky.social and I are celebrating #PhycologyFriday by continuing to collect data for our long-term monitoring project that is now accepted! cdnsciencepub.com/doi/abs/10.1...

Read it for free on BioRXiv

🦑🧪 #botany #ecology #phycology