Saltmarsh School

Learn the rocky shore, one tide at a time

A six-week online course on how barnacles, mussels, and kelp divide up a few vertical meters of coastline. Drag the tide below and watch who gets wet.

Splash High Middle Low Subtidal

Six weeks, one shoreline

Each week pairs a 40-minute video lecture with a field task you can do on any rocky coast, or from our photo sets if you live inland.

  1. Week 1

    Reading the vertical gradient

    Why a 2-meter change in elevation can matter more than 200 kilometers of latitude. You'll sketch your first transect.

  2. Week 2

    Desiccation and the upper limit

    How periwinkles and barnacles survive hours of sun, and the 1961 Connell experiment that moved a species line by hand.

  3. Week 3

    Predators set the lower limit

    Sea stars, whelks, and crabs. Keystone species explained with the Paine mussel-removal data.

  4. Week 4

    Seaweed strategies

    Rockweed, sea lettuce, and kelp: holdfasts, air bladders, and how each handles wave force.

  5. Week 5

    Tidepools as small worlds

    Temperature swings, oxygen crashes at noon, and the fish that live through them.

  6. Week 6

    Your transect report

    Combine your counts into a six-page report and present it in a live peer review session.

Try a question from Week 2

Typical of the weekly checks. Ungraded, and you can retry.

Acorn barnacles thrive high on the shore but vanish near the low-tide line. What most likely stops them from living lower?

Who teaches it

Two working marine ecologists who still spend most low tides on actual rocks.

Dr. Imani Okafor-Reyes

Lead instructor, intertidal ecology

Spent eleven summers surveying mussel beds along the Oregon and Washington coast. Her 2019 paper on heat-wave die-offs is assigned reading in Week 2.

Tomasz Wieliczko

Field methods and seaweed biology

Former harbor pilot turned phycologist. He runs the Week 4 identification clinic and answers questions in the forum before breakfast, usually.

Next cohort starts January 12

Class size is capped at 60 so every transect report gets real feedback.

Duration
6 weeks
Time per week
About 4 hours
Live sessions
Thursdays, 7 pm Pacific
Tuition
$149, or free with a library card