Seaweeds are algae, mostly attachted to the ground. Some of them
can be found on the shore, attached to the seabottom or rocks.
Only the most well known will be discussed here.
The tree groups of seaweed
- The green seaweeds or Chlorophyta.
Ulva is the most well known.The green seaweeds
only grow near the surface, often
attached to rocks. They grow fast.
- The red seaweeds or Phaeophyta.
They grow in deeper water, attached to the bottom.
Dulse is de most popular seaweed as it is very tasty.
- The brown seaweeds or Rhodophyta
The most abundant group, with the kelp
as the most well known.
These seaweeds can be found attached on rocks :
1 Oarweed , can only be found at low tide ( sublittoral).
2 Bladder wrack is very common atached to rocks and stones.
3 Red seaweed with leave-like structures is very common
Bladderwrack
Bladderwrack (Fucus vesiculosus), a browm algae with olive
brown vesiclesis, is probably the most well
known of the seaweeds, covering large parts of rocks in
the low tide zone. It is attached on submerged rocks.
It forms flaoting banks wich gives covers for huge
amounts of small fish and other creatures.
Bladderwrack leaves contain large amounts of iodium, and for this
reason its often an ingredient of a iodium supplements.
Regular consumption of bladderweack could result in levels
of iodine sufficient to cause thyroid problems.
( a disease of the thyroid gland).
Green laver or sea lettuce
Ulva latissima or green laver is a green seaweed, with
very thin , almost transparant leaves. Its a very fast
growing seaweed, but can easely be damaged. As the name
suggest it can be eaten, like all other seaweed and has a
fine nutty tast.
Ulva is a good addition in a Nothsea or coast aquarium,
it grows fast and remives a lot of nitrates from the water,
purple laver or dulse
<
Dulse, purple laver(Palmaria palmata) is a red seaweed that is popular
in seadishes. It grows attached to submerged rocks. Dulse is
fast growing seaweed, and a adapts easely to a Northsea aquarium.
Seaweed in the ocean
The kelp grows much larger in the ocean, forming 30 meter long stipes
(stems). The Giant Kelp can become even longer, attached to the
rocky bottom by its holdfast.
More to the North , on can find Lamanaria groenlandica, another
giant kelp, Nereocystis luetkeana is bundant in the east and
North of the Pacific ocean. It has an airbladder that keeps it
stipe vertical.
The reproduction of kelp
The kelp (belonging to the family of Laminariales) has cells that
contain chromsomes that , just like humans, consist of two
simular parts. (diploid). Reproduction start by dividing the
chromsomes in two parts. Cells that contain such an haploid
chromosome can swim freely and attache itself to the bottom
of the sea, becoming a small plant. Here it forms
spermatoids, that fertilize an egg, the start of an new
doploid kelp. The proces is simular to that of the reproduction
of the ferns.
Sargossawood in de Oceanen
The Sargossaweed belongs to the groupe of algae, and is not
a seaweed. It floats in the ocean between Afrika and South America.
The Ocean is much to deep , so they are free floating. But there
is no stream in that part of the ocean. The Sargossa is full of small
fishes and other creatures.
Every seaweed has is own optimal depth.
Seaweed in the Northsea
Seaweed form large woods on the sandy bottom of the
Northsea , providing shelter for very many small animals,
like shrimps, young fishes.
Red kelp is most abundant of those seaweeds. During storm
the holdcast to the seabottom can loose its grip on the
sandy bottom. The kelp can attache itself to another place
or get lost on the beach.
Fishery damages those Red kelpwoods, directly by there nets
but also by catching the Atlantic cod. The Atlantic cod
feed on Sea urchins that eat the Red kelp.
Red Kelp
red kelp (Laminaria digitata) forms kelpwouds in the Northsea
gtiving shelterto many small seacreatures.
Red kelp can be aeten and is tasty, it can be
collected at low tide.
Atlatic cod and Haddock hunting for Herring.
A painting from 1880 made by Heinrich Harder.
1Atlantic cod
2 Herring
3 Haddock
4 Oarweed
Haddock is smaller then the Atlantic cod nd has an sharp dosal fin.
As Haddock feeds urgin , the decline of Haddock isw one of
the causes of the decline of the Oarweed.
The well known seaweeds of the Atlantic ocean:
1Sargassum, brown seaweed .
2Macrocystis pyrifera, Giant kelp, a brown seaweed.
3Nereocystis Luetkeana, old, Bulb Kelp a brown seaweed.
4Nereocystis Luetkeana, young.
5Agarum cribrosum, The Colander weed , a brown seaweed.
6Laminaria Bongardiana, Laminaria groenlandica, a brown seaweed.
7Lessonia fuscescens, Brown kelp, Giant bladder kelp, a brown seaweed.
8 Rhodymenia palmata, grannogh, dillisk, a red saeweed.
9Fucus vesiculosus, Bladder wrack, .
10Schizimenia edulis
11Iridaea, Ginnanso .
12Constantinea Rosmarina
13Halosaccion hydrophora
14Alaria esculenta, badderlocks, winged kelp
15Thalassophyllum Clathrus
16Odonthalia Gmelini, red seaweed
17Chondis crispus, Irish moss, or carrageen moss.
18Laminaria digitata,
19Laminaria sacharina, .
20Delesseria sanguinea
Edible seaweed
All seaweed is edible, but the following
are also tasty:
Nori (Porpyra)
Nori has a fine taste that resembles mushroom
flavour and is used in soup and sushi. It is
sold as thin , dried sheets and should be
cooked shortly.
Irish moss (Chondrus crispus)
This seaweed contains the substance carrageen
and is used in preparing jellies and soups,
and also in wine and beer production.
.
Dulse
The very nice tasting Dulse is sold dried or fresh.
it can be cooked shortly or eaten fresh,and is used
in soups and salades.
Wakame
wakame has strong taste , like seafruit, and is used
in soup. as it has a strong taste, it should be used only
in small amounts. It contains no calories.
Thongweed (Himanthalia elongata)
A seaweed that forms long thin threads and has strong
fishy taste. It is used in soups and seafruit dishes.
Kombu or kelp (Laminaria japonica)
The Atlantic and Pacific kelp is eaten as a vegetable by
the Japanese (dashima) and Chinese (haidai).
Kombu is used in large quantities in soup , the Japanese
soup is called daishi.