1. 1.b. Macroalgae
In freshwater biota: Charophytes limited to oligotrophic, alkaline waters.

2. Charophyta: left: dense vegetation;
Right: detail.

3. 1.b. Macroalgae
In freshwater biota: limited: Charophytes
Along coastlines: on rocky substrate + in mangroves + in salt marshes + on seagrasses.

4. Rocky shore with extensive macroalgal (seaweed) vegetations.

5. Mangrove with aerial roots (pneumatophores) densely covered by epiphytic algae, mainly red algae (Rhodophyta).

6. Seaweed growth in a young salt marsh vegetation (Salicornia europaea).

7. Macroalgae in seagrass vegetations: the brown alga Dictyota epiphytic on Thalassodendron ciliatum.

8. In freshwater biota: limited: Charophytes
1.b. Macroalgae
In freshwater biota: limited: Charophytes
Along coastlines: rocky substrate + mangroves + salt marshes + seagrasses.
Plant body = thallus: NO vascular bundles (no "true" roots, stems nor leaves although they can look like -); NO flowers; NO seeds (spores!).

9. Chlorophyta: Caulerpa sertularioides: structures SIMILAR to higher plants: stolonoïds, rhizoïds and feathery assimilators.

10. Phaeophyta: Laminaria: structures SIMILAR to higher plants: haptera, stipe and blade.

11. Rhodophyta: Zellera tawallina with holdfast, stem-like and blade-like structures.

12. In freshwater biota: limited: Charophytes
1.b. Macroalgae
In freshwater biota: limited: Charophytes
Along coastlines: rocky substrate + mangroves + salt marshes + seagrasses.
Plant body = thallus: NO vascular bundles (no "true" roots, stems nor leaves); NO flowers; NO seeds (spores!).
Photosynthesis and uptake of nutrients by whole thallus.

13. In freshwater biota: limited: Charophytes
1.b. Macroalgae
In freshwater biota: limited: Charophytes
Along coastlines: rocky substrate + mangroves + salt marshes + seagrasses.
Plant body = thallus: NO vascular bundles (no "true" roots, stems nor leaves); NO flowers; NO seeds (spores!).
Photosynthesis and uptake of nutrients by whole thallus.
Underestimated in biodiversity discussions ("invisible").

14. In freshwater biota: limited: Charophytes
1.b. Macroalgae
In freshwater biota: limited: Charophytes
Along coastlines: rocky substrate + mangroves + salt marshes + seagrasses.
Plant body = thallus: NO vascular bundles (no "true" roots, stems nor leaves); NO flowers; NO seeds (spores!).
Photosynthesis and uptake of nutrients by whole thallus.
Underestimated in biodiversity discussions ("invisible").
Requirements for development:
* Salt or brackish water (rare exceptions);

15. In freshwater biota: limited: Charophytes
1.b. Macroalgae
In freshwater biota: limited: Charophytes
Along coastlines: rocky substrate + mangroves + salt marshes + seagrasses.
Plant body = thallus: NO vascular bundles (no "true" roots, stems nor leaves); NO flowers; NO seeds (spores!).
Photosynthesis and uptake of nutrients by whole thallus.
Underestimated in biodiversity discussions ("invisible").
Requirements for development:
* Salt or brackish water (rare exceptions);
* Submerged, at least part of the day;

16. In freshwater biota: limited: Charophytes
1.b. Macroalgae
In freshwater biota: limited: Charophytes
Along coastlines: rocky substrate + mangroves + salt marshes + seagrasses.
Plant body = thallus: NO vascular bundles (no "true" roots, stems nor leaves); NO flowers; NO seeds (spores!).
Photosynthesis and uptake of nutrients by whole thallus.
Underestimated in biodiversity discussions ("invisible").
Requirements for development:
* Salt or brackish water (rare exceptions);
* Submerged, at least part of the day;
* Hard substrate: lithophytes (few exceptions: special anchorage).

17. 1.b. Macroalgae
Species diversity: approximate numbers
Red (Rhodophyta = ± spp), green (Chlorophyta (macroalgae only!) = ± 2000 spp (+ microalgae = ~ 15000) and brown (Phaeophyta = ± spp) algae [and blue-greens: see micro-algae].

18. Species diversity: approximate numbers
1.b. Macroalgae
Species diversity: approximate numbers
Red (Rhodophyta = ± spp), green (Chlorophyta (macroalgae only!) = ± 2000 spp (+ microalgae = ~ 15000) and brown (Phaeophyta = ± spp) algae [and blue-greens: see micro-algae].
Some area's more species rich than others: Pacific: Philippines, Japan; Atlantic: Europe!! (N-Spain, France, UK); Caribbean!! Red Sea & Indian Ocean?? South Africa!! (different climate zones).

19. Species diversity: approximate numbers
1.b. Macroalgae
Species diversity: approximate numbers
Red (Rhodophyta = ± spp), green (Chlorophyta (macroalgae only!) = ± 2000 spp (+ microalgae = ~ 15000) and brown (Phaeophyta = ± spp) algae [and blue-greens: see micro-algae].
Some area's more species rich than others: Pacific: Philippines, Japan; Atlantic: Europe!! (N-Spain, France, UK); Caribbean!! Red Sea & Indian Ocean?? South Africa!! (different climate zones)
Most species rich: not tropics >< terrestrial plants.

20. Chlorophyta (green algae)
More closely related to higher plants than to the brown or red algae!!: photosynthesis by chlorophyll a & b, storage product = starch, cell wall component: cellulose.

21. Chlorophyta (green algae)
More closely related to higher plants than to the brown or red algae!!: photosynthesis by chlorophyll a & b, storage product = starch, cell wall component: cellulose.
Ulva (incl. Enteromorpha): bioindicators of eutrophication (+ importance of correct ID!!)

22. Chlorophyta: Ulva lactuca, Sea lettuce (Wimereux): 2-layered membrane, ~ 20 cm large.

23. Chlorophyta: Ulva (Enteromorpha) intestinalis, Intestine weed (Wimereux): 30 cm long.

24. Chlorophyta: massive development of Ulva in the intertidal (Wimereux) as a result of eutrophication of the coastal water.

25. Chlorophyta: Cladophora (Rockweed): habit and detail
Chlorophyta: Cladophora (Rockweed): habit and detail. Some species growing in freshwater.

26. Chlorophyta: Bryopsis spp.

27. Chlorophyta (green algae)
More closely related to higher plants than to the brown or red algae!!: photosynthesis by chlorophyll a & b, storage product = starch, cell wall component: cellulose.
Ulva (incl Enteromorpha): bioindicators of eutrophication (+).
Codium: locally as food.

28. Chlorophyta: Codium.

29. Chlorophyta (green algae)
More closely related to higher plants than to the brown or red algae!!: photosynthesis by chlorophyll a & b, storage product = starch, cell wall component: cellulose.
Ulva (incl Enteromorpha): bioindicators of eutrophication (+).
Codium: locally as food.
Halimeda: calcified -> sediments (‘Halimeda-sand’!! (atolls: up to 90%).

30. Chlorophyta: Halimeda copiosa
Calcified, segmented thallus (one segment ~ 0.5 cm).

31. Chlorophyta: Halimeda tuna (fertile, with gametangia.

32. Chlorophyta (green algae)
More closely related to higher plants than to the brown or red algae!!: photosynthesis by chlorophyll a & b, storage product = starch, cell wall component: cellulose.
Ulva (incl Enteromorpha): bioindicators of eutrophication (+).
Codium: locally as food.
Halimeda: calcified -> sediments!! (atolls: up to 90%)
Caulerpa: food/toxic; C. taxifolia & C. racemosa-problem in the Mediterranean Sea.

33. Chlorophyta: Caulerpa racemosa var. racemosa: spherical assimilators.

34. Chlorophyta: Caulerpa opposita typespecimen of a new species but locally extremely abundant.

35. Phaeophyta (brown algae)
Photosynthetic pigments: chlorophyll a & c + brown pigments (xanthophylls); cell wall component: alginates (see Human uses)!

36. Phaeophyta (brown algae)
Photosynthetic pigments: chlorophyll a & c + brown pigments (xanthophylls); cell wall component: alginates !
Mainly cold water (exceptions).

37. Phaeophyta (brown algae)
Photosynthetic pigments: chlorophyll a & c + brown pigments (xanthophylls); cell wall component: alginates !
Mainly cold water (exc.)
From small and filamentous up to 65 m long; haptera (root-like) + stipe (stem-like) + lamina (blade-like) + bladders (floating).

38. Phaeophyta: Pylaiella littoralis: habit: branched filamentous (Wimereux): detail of a portion ~ 5 cm long.

39. Phaeophyta: Laminaria saccharina, large specimen in Brittany (Roscoff): ERASMUS field-course.

40. Phaeophyta: Laminaria saccharina: haptera, stipes, meristematic zone (arrows), basis of the blade (Wimereux).

41. Phaeophyta: Laminaria saccharina: blades with double row of undulations.

42. Phaeophyta: Fucus vesiculosus, Bladder weed (Wimereux) with air vesicles (floating).

43. Phaeophyta (brown algae)
Photosynthetic pigments: chlorophyll a & c + brown pigments (xanthophylls); cell wall component: alginates !
Mainly cold water (exc.)
From small and filamentous up to 65 m long; haptera (root-like) + stipe (stem-like) + lamina (blade-like) + bladders (floating).
Zonation! Adaptation to dessication, salinity and temperature fluctuations + competition.

44. Phaeophyta: Pelvetia canaliculata-vegetation in the upper intertidal (Wimereux).

45. Phaeophyta: Fucus spiralis with numerous receptacles (swollen reproductive structures) in the high intertidal.

46. Phaeophyta: Fucus vesiculosus, in the middle intertidal (Wimereux).

47. Phaeophyta: Ascophyllum nodosum: replacing Fucus vesiculosus on sheltered places (Wimereux).

48. Phaeophyta: Fucus serratus, low intertidal (Wimereux).

49. Phaeophyta: Himanthalea elongata: zone between intertidal and subtidal (Brittany).

50. Phaeophyta: Laminaria-zone at spring low tide: Wimereux (L
Phaeophyta: Laminaria-zone at spring low tide: Wimereux (L. saccharina, L. digitata).

51. Phaeophyta (brown algae)
Photosynthetic pigments: chlorophyll a & c + brown pigments (xanthophylls); cell wall component: alginates !
Mainly cold water (exc.)
From small and filamentous up to 65 m long; haptera (root-like) + stipe (stem-like) + lamina (blade-like) + bladders (floating).
Zonation! Adaptation to dessication, salinity and temperature fluctuations + competition.
Dictyota & Padina frequent in tropics; also Sargassum ID-problems!! + drifting spp.

52. Phaeophyta: Dictyota dichotoma.

53. Phaeophyta: Padina pavonica in situ (Mediterranean Sea).

54. Phaeophyta: Sargassum muticum (Japweed) in situ in a low intertidal rock pool.

55. Phaeophyta: Sargassum muticum (Japweed): detail with air bladders and receptacles (Wimereux).

56. Rhodophyta (red algae)
Photosynthetic pigments: chlorophyll a + red and blue pigments; cell wall component: carrageenans, agar, chalk (see Human Uses).

57. Rhodophyta (red algae)
Photosynthetic pigments: chlorophyll a + red and blue pigments; cell wall component: carrageenans, agar, chalk!
Mainly warm water (exceptions!).

58. Rhodophyta (red algae)
Photosynthetic pigments: chlorophyll a + red and blue pigments; cell wall component: carrageenans, agar, chalk!
Mainly warm water (exceptions!).
From small and filamentous up to 1 m long; mostly composed of filaments sticking together by jelly.

59. Rhodophyta: Acrochaetium: top left: tufts of small filaments (~1 cm); other illustrations: microscopic details with spore formation.

60. Rhodophyta: Palmaria palmata, a tough, relatively large (~ 20 cm), blade-like red alga (Wimereux, subtidal fringe).

61. Rhodophyta: Batrachospermum: detail of the anatomy: filaments sticking together by jelly: central axis and whorls of branchlets.

62. Rhodophyta (red algae)
Photosynthetic pigments: chlorophyll a + red and blue pigments; cell wall component: carrageenans, agar, chalk!
Mainly warm water (exc.)
From small and filamentous up to 1 m long; mostly composed of filaments sticking together by jelly.
Mostly epilithic, but numerous epiphytic species. Zonation! Mainly subtidal + intertidal pools (desiccation).

63. Rhodophyta: Palmaria palmata (red arrows), in situ, epilithic and the brown algae Laminaria digitata ( brown arrow) and L. saccharina (yellow arrow) (Wimereux).

64. Rhodophyta: Polysiphonia lanosa, epiphytic (hemi-parasitic) on Ascophyllum nodosum (brown alga) (Wimereux): detail.

65. Collecting red algae in an intertidal rock pool (uplift).

66. Subtidal fringe close to Digue Nord (Boulogne): zone dominated by red algae.

67. Rhodophyta (red algae)
Photosynthetic pigments: chlorophyll a + red and blue pigments; cell wall component: carrageenans, agar, chalk!
Mainly warm water (exc.)
From small and filamentous up to 1 m long; mostly composed of filaments sticking together by jelly.
Mostly epilithic, but numerous epiphytic species. Zonation! Mainly subtidal + intertidal pools (desiccation).
Porphyra (nori): most important sea-vegetable!! Mariculture. Fundamental research (reproduction) --> applied research.

68. Rhodophyta: Porphyra purpurea: habit: membranous blade of ~ 30 cm long (Wimereux).

69. The story of Nori and Kathleen Drew
Traditional: Porphyra growing on Bamboo (Hibi).

70. The story of Nori and Kathleen Drew
discovery of the life cycle: Conchocelis-phase by K. Drew
triphasic, anisomorphic cycle
tetraspores (conchospores) grow in oyster shells

71. Nori: now a modern industry.

72. Caulerpa racemosa sold as vegetable in Thailand

73. Caulerpa racemosa sold as vegetable in Thailand

74. Rhodophyta (red algae)
Photosynthetic pigments: chlorophyll a + red and blue pigments; cell wall component: carrageenans, agar, chalk!
Mainly warm water (exc.)
From small and filamentous up to 1 m long; mostly composed of filaments sticking together by jelly.
Mostly epilithic, but numerous epiphytic species. Zonation! Mainly subtidal + intertidal pools (desiccation).
Porphyra (nori): most important sea-vegetable!! Mariculture. Fundamental research (reproduction) --> applied research.
Eucheuma (a.o.) --> carragheenophytes!! Mariculture.

75. Rhodophyta: Eucheuma sp. (Tanzania): carragheenophyte.

76. Rhodophyta: mariculture of Eucheuma in Indonesia: attaching branches on the ropes; in the background: bags of dried specimens.

77. Rhodophyta: mariculture of Eucheuma in Indonesia: bamboo floaters with ropes.

78. Rhodophyta: mariculture of Eucheuma in Indonesia: ropes with young attached specimens.

79. Rhodophyta: mariculture of Eucheuma in Indonesia: underwater image (seagrasses on the seabottom).

80. Rhodophyta: mariculture of Eucheuma in Indonesia: fully grown specimens ready for collecting.

81. Rhodophyta: mariculture of Eucheuma in Indonesia: collecting the fully grown specimens in boats.

82. Rhodophyta: mariculture of Eucheuma in Indonesia: drying in the sun.

83. Rhodophyta (red algae)
Photosynthetic pigments: chlorophyll a + red and blue pigments; cell wall component: carrageenans, agar, chalk!
Mainly warm water (exc.)
From small and filamentous up to 1 m long; mostly composed of filaments sticking together by jelly.
Mostly epilithic, but numerous epiphytic species. Zonation! Mainly subtidal + intertidal pools (desiccation).
Porphyra (nori): most important sea-vegetable!! Mariculture. Fundamental research (reproduction) --> applied research
Eucheuma (a.o.) --> carragheenophytes!! Mariculture.
Gelidium: --> agar. Mariculture.

84. Rhodophyta: Gelidium pulchellum (agarophyte, Brittany).

85. Rhodophyta (red algae)
Photosynthetic pigments: chlorophyll a + red and blue pigments; cell wall component: carrageenans, agar, chalk!
Mainly warm water (exc.)
From small and filamentous up to 1 m long; mostly composed of filaments sticking together by jelly.
Mostly epilithic, but numerous epiphytic species. Zonation! Mainly subtidal + intertidal pools (desiccation).
Porphyra (nori): most important sea-vegetable!! Mariculture. Fundamental research (reproduction) --> applied research
Eucheuma (a.o.) --> carragheenophytes!! Mariculture.
Gelidium: --> agar. Mariculture.
Corallines: "cement in coral reefs"; Med. Sea: calcified platform; coralligène; maërl (industry --> destroyed).

86. Dead coral skeletons, completely overgrown by Corallinaceae (calcified red algae).

87. The seaward, surf-exposed margin of the reef, cemented by Corallinaceae, resulting in a pinkish colour.

88. The seaward, surf-exposed margin of the reef, cemented by Corallinaceae.

89. Rhodophyta: Corallinales
Rhodophyta: Corallinales. Encrusting representative: Phymatolithon lenormandii on rock (Brittany).

90. Rhodophyta: Corallinales
Rhodophyta: Corallinales. Pseudolithophyllum expansum (with epiphytic Halimeda): forming extensive structures at great depth (>50 m), the “coralligène” (Mediterranean Sea).

91. Rhodophyta: Corallinales: Lithophyllum tortuosum: forming a ridge (“le trottoir”) at high tide sea level, especially at surf-exposed sites (Mediterranean Sea).

92. Rhodophyta: Corallinales: Lithophyllum tortuosum-"trottoir" (Mediterranean Sea).

93. Rhodophyta: Corallinales
Rhodophyta: Corallinales. Segmented representatives: left: Corallina officinalis, right: Cheilosporum sagittatum (Australia).

94. Rhodophyta (red algae)
Some other representatives from the N-French coast (Wimereux).

95. Rhodophyta: Gracilaria gracilis: (Wimereux), a carragheenophyte.

96. Rhodophyta: Chondrus crispus (Irish moss): (Wimereux): carragheenophyte.

97. Rhodophyta : Plocamium cartilagineum (Wimereux).

98. Succession; zonation; niche diversity
Bare surface -> Bacteria -> filamentous algae -> 'fleshy' seaweeds (-> seagrasses).

99. Succession; zonation; niche diversity
Bare surface -> Bacteria -> filamentous algae -> 'fleshy' seaweeds (-> seagrasses).
Conspicuous zonation (species according climate).
- Intertidal: exposure to air conditions towards high tide: desiccation, temperature & salinity variations!
- Subtidal: wave action & light (quality and quantity); down to depth with enough light for photosynthesis.

100. Dike at Pointe de la Crèche, Boulogne (N France): Verrucaria maura (blackish lichen), Blidingia minima (light green), Porphyra umbilicalis (brownish purple), Ulva compressa (dark green), Fucus spiralis (blackish brown), on the bottom: many Ulva.

101. Zonation in the Mediterranean Sea: intertidal with Rissoella verruculosa, Lithophyllum tortuosum, Cystoseira mediterranea.

102. Succession; zonation; niche diversity
Bare surface -> Bacteria -> filamentous algae -> 'fleshy' seaweeds (-> seagrasses).
Conspicuous zonation (species according climate).
Intertidal: exposure to air conditions towards high tide: desiccation, temperature & salinity variations!
Subtidal: wave action & light (quality and quantity); down to depth with enough light for photosynthesis
Geographic distribution: 5 marine phytogeographical zones (upper and lower boreal, temperate, subtropical and tropical) defined by critical temperatures:
- min temperature for survival;
- min temperature for repopulation;
- max temperature for repopulation;
- max temperature for survival.

103. Succession; zonation; niche diversity
Bare surface -> Bacteria -> filamentous algae -> 'fleshy' seaweeds (-> seagrasses).
Conspicuous zonation (species according climate).
Intertidal: exposure to air conditions towards high tide: desiccation, temperature & salinity variations!
Subtidal: wave action & light (quality and quantity); down to depth with enough light for photosynthesis
Geographic distribution: 5 marine phytogeographical zones:
- min temperature for survival;
- min temperature for repopulation;
- max temperature for repopulation;
- max temperature for survival.
Cosmopolitan species (??!! >< molecular data -> numerous sibling species). Patchiness!! Disjunct distribution.

104. Research along the East African coast
New records
update of floristic knowledge
48 species new to Kenya and Tanzania
Example
Dictyota adnata Zanardini
type locality: Irian Jaya (Indonesia)
New: East Africa
Coppejans (1990)
Research Group Phycology, Ghent University

105. Research along the East African coast
Gibsmithia hawaiiensis
type locality: Hawaii
known from Australië
new: East Africa, South Africa Seychelles
subtidal
De Clerck et al., Bot. Mar. (subm.)
Research Group Phycology, Ghent University

106. Research along the East African coast
New species
Vanvoorstia incipiens intertidal 1 location: Uroa, Zanzibar
De Clerck, Wynnne & Coppejans, Phycologia (1999)
Research Group Phycology, Ghent University

107. Ecological roles of the seaweed vegetations
Defining intertidal and subtidal habitats (incl. fauna!)

108. Ecological roles of the seaweed vegetations
Defining intertidal and subtidal habitats (incl. fauna!)
Large biomass, even in mangroves and seagrass vegetations -> important role!

109. Ecological roles of the seaweed vegetations
Defining intertidal and subtidal habitats (incl. fauna!)
Large biomass, even in mangroves and seagrass vegetations -> important role!
Consumption, phycocolloids.

110. Algal uses and economical potential
food
fertilisers
phycocolloids
fine biochemicals
(fermentation and pyrolysis)

111. Algal uses and economical potential
Human food
600 BC
“Some algae are a delicacy fit for the most honoured guests, even for the King himself”
21 species are used in Japan, 10% of the daily diet
Nori = Porphyra
Kombu = Laminaria
Wakame = Undaria

112. Algal uses and economical potential
Human food
Europe and America
health food
traditional foods
laver bread (Porphyra)
cheese (Dulse: Palmaria palmatifida)
dying agents for textiles
pharmaceuticals (since pre-christian times: ~ officinalis)

113. Ecological roles of the seaweed vegetations
Defining intertidal and subtidal habitats (incl. fauna!)
Large biomass, even in mangroves and seagrass vegetations -> important role!
Consumption, phycocolloids.
Pollution, eutrophication: 'greening of the coast': Ulva (incl. Enteromorpha).