Tidewater Institute

Course notes

Seven short units on the coast, a glossary, activity plans and a printable summary.

The seven units

  1. Tides, waves and erosion. Why the sea rises and falls twice a day, how waves move sand and rock, and how coasts are defended.
  2. Tide pools. Why barnacles, limpets and sea stars live in bands on a rock that is underwater for only part of the day.
  3. Salt marshes. The grassy, flooded edges of sheltered coasts, and the quiet work they do for fish, water and storm defence.
  4. Mangroves. Trees with their roots in salty tidal mud, and why tropical coasts depend on them.
  5. Seagrass meadows. Flowering plants that live underwater, and the turtles, fish and carbon stores that depend on them.
  6. Coral reefs. How tiny animals and algae build reefs, and why warm water makes corals bleach.
  7. Plankton and food webs. The drifting base of the ocean’s food web and how energy passes from one feeder to the next.

How each unit is built

  • In brief: the main idea in three sentences.
  • What it is, why it matters, how it works: the idea in depth, with tables.
  • Effects and pressures: what changes the habitat and what can be done.
  • Field exercise: a small task that needs only a notebook.
  • Check yourself: questions with answers hidden until you open them.
  • Basis of the facts: where the facts come from.

A unit takes about ten to fifteen minutes to read. There are no accounts or timetables.

Coastal habitats compared

Five coastal habitats side by side
HabitatWhere it livesMain buildersSubstrateMain servicesMain pressures
Rocky shoreAnywhere with hard rock, mostly cooler seasBarnacles, mussels, seaweedsRockFood web base; research and learningTrampling, heat, pollution
Salt marshSheltered mud coasts, mostly cooler seasCordgrass, glasswort and other salt-tolerant plantsMud and fine sandNursery, filter, wave cushion, carbonDrainage, squeeze, nutrients
Mangrove forestSheltered tropical and subtropical shoresMangrove treesSoft mudNursery, coast protection, carbon, woodClearing, ponds
Seagrass meadowShallow, sheltered seas on most coastsSeagrass plantsSand and mudFood, nursery, steadies sediment, carbonCloudy water, dredging, heat
Coral reefWarm, clear, shallow tropical seasReef-building corals and algaeLimestone it buildsHabitat, wave protection, foodHeat, acidification, runoff

Two reading routes

Quick route. Read the printable summary, then the “In brief” box of each unit.

Full route. Read the units in order, do each field exercise, answer the questions, and check terms in the glossary. A teacher can use the activity plans alongside.