When you first start learning about seaweeds, it can feel overwhelming. There are so many plants on the shoreline, each with its own shape, colour, and name.

When I began foraging for seaweed, I would walk along the shore with a small guidebook, trying to identify everything I saw. I would photograph dozens of plants, planning to look them up later. But before long my enthusiasm would fade — there simply seemed to be too many.

Eventually, I realised something important.

You don’t need to learn everything.

This is not an exam.

Instead, start by learning to confidently recognise one or two seaweeds. Over time they will become familiar — like spotting a friendly face in a crowd. Slowly, you will add more to your bank of knowledge.

Ireland’s exposed Atlantic coastline is an extraordinary place to begin. Beneath the rockpools and tidal ledges lie forests of seaweed: shining caramels of oarweed, golden channelled wrack, deep olives of kelp, bright greens of sea lettuce and rich burgundy reds of dillisk.

Before learning the plants themselves, it helps to understand when and where to look.

When to Go Seaweed Foraging

Time of Year

In Ireland, spring and early summer are the best seasons for seaweed foraging.

While trees on land may still be bare in March and early April, seaweeds are already growing quickly beneath the water.

In spring, the plants are:

• smaller
  

• more tender
  

• brightly coloured
  

Later in the summer, the sun begins to bleach many seaweeds, and the plants can become tougher.

Time of Month

The easiest time to reach many seaweeds is during spring tides, when the sea retreats further than usual.

Spring tides occur twice each lunar month, around:

• the full moon
  

• the new moon
  

These tides expose more of the lower shore, where many kelps and other seaweeds grow.

Time in the Tide

Seaweeds grow in different tidal zones.

Some grow high on the shore and are easy to reach, while others grow much lower and are only visible at very low tide.

For beginners it is best to:

• head out one to two hours before low tide
  

• explore while the tide is still going out
  

• keep an eye on the sea as the tide turns
  

This gives you plenty of time to explore safely.

Where to Look

Ireland’s rocky Atlantic coastline provides ideal conditions for seaweeds.

The best places to explore are:

• rocky shores
  

• tidal ledges
  

• rockpools
  

• areas exposed to clean ocean water
  

Avoid areas near harbours, marinas or polluted water.

Safety on the Shore

A few simple precautions will make your foraging trip much more enjoyable.

Only harvest living seaweed
Pick seaweeds that are still attached to rocks rather than those washed up by the tide.

Watch your footing
Seaweed-covered rocks can be extremely slippery. Move slowly and step carefully.

Check the tide
 Always be aware of a rising tide and make sure you have a clear route back to shore.

Eight Seaweeds to Begin With

These eight seaweeds are distinctive and relatively easy for beginners to recognise.

Beginner identification tip:
 Look for soft red fronds shaped like many small fingers or gloves growing directly from the rock.

2. Pepper Dulse

Osmundea pinnatifida

Pepper dulse is a small seaweed that grows on rocks, often hidden beneath larger plants. Its flattened fronds branch irregularly and vary in colour from yellow-green to deep brown.

Beginner identification tip:
 If you find a small brown seaweed hidden under others with a strong truffle-like taste, it is likely pepper dulse.

3. Sea Lettuce

Ulva lactuca

Sea lettuce grows in thin, bright green translucent sheets that resemble delicate lettuce leaves. It is often found in rockpools and shallow water.

Beginner identification tip:
Look for bright green, paper-thin sheets that feel almost like wet silk.

4. Nori (Laver)

Porphyra umbilicalis

Nori is another sheet-like seaweed common on exposed coastlines. It appears reddish-purple in water but turns very dark, almost black, when dry on rocks.

Beginner identification tip:
 Look for thin purple sheets in the water that turn black and papery when dry.

5. Oarweed (Kombu Kelp)

Oarweed is a large brown kelp that grows in underwater forests on the lower shore. It forms broad, leathery blades attached to rocks.

Beginner identification tip:
Look for large, wide brown blades growing in clusters in the deeper tidal zone.

7. Bladderwrack

Fucus vesiculosus

Bladderwrack grows on the mid-shore and is recognised by its forked fronds and pairs of small air-filled bubbles along the plant.

Beginner identification tip:
Look for olive-brown seaweed with pairs of little air bubbles along the fronds.

8. Atlantic Wakame

Alaria esculenta

Atlantic wakame grows near the lowest water mark and has long yellow-olive fronds with a central rib.

Beginner identification tip:
 Look for a long kelp leaf with a clear central rib and ruffled edges.

• Gather only live seaweeds that are still attached to the rocks, not those washed up by the tides. Old, decomposing seaweeds are pretty easy to sniff out.

• Be aware of water quality and pollution. Don’t pick from stagnant water, rockpools that aren’t regularly refreshed, busy harbours, ports etc. Also consider general ocean water quality and the possibility of toxic algae blooms (especially in summer).

• Most seaweed foraging will take you to some treacherously slippery rocks and unforgiving tides. Stay switched on, consult tide tables before hand, if in doubt tread between rather than on rocks, seek out non-slip barnacles.

• The tide waits for no man, be aware of a rising tide and always keep an eye on your route back to dry land.