Seaweed activity

Hypobromous acid so produced from the naturally occurring bromide in the ocean is rapidly consumed upon demand and is nontoxic to the plant. This natural process helps explain why seaweeds in the ocean are not overcome by adherent microbial biomass and macrofoulants that, for example, rapidly foul the surfaces of ships and piers in the sea. Although chloride is far more abundant than bromide, certain seaweeds preferentially make hypobromous acid in situ. The brominating activity of Laminaria digitata is shown by demonstration (Figure 3) in a replication of the work by Wever, et al.2. 

The existence of only a few well-understood examples of activated defenses of seaweeds seems thus to be due more to a restricted methodological approach... 

Kim J, Choi JS, Kang SE, Cho JY, Jin HJ, Chun BS, Hong YK (2004) Multiple allelopathic activity of the crustose coralline alga Lithophyllum yessoense against settlement and germination of seaweed spores. J Appl Phycol 16 175-179... 

Ceh J, Molis M, Dzeha TM, Wahl M (2005) Induction and reduction of anti-herbivore defenses in brown and red macroalgae off the Kenyan coast. J Phycol 41 726-731 Cetrulo GL, Hay ME (2000) Activated chemical defenses in tropical versus temperate seaweeds. Mar Ecol Prog Ser 207 243-253... 

Cetrulo GL, Hay ME (2000) Activated chemical defenses in tropical versus temperate seaweeds. Mar Ecol Prog Ser 207 243-253... 

WeverR, TrompMGM, Krenn BE, Maijani A, Van Tol M (1991) Brominating activity of the seaweed Ascophyllum nodosum, impact on the biosphere. Environ Sci Technol 25 446-449 Wichard T, Pohnert G (2006) Formation of halogenated medium chain hydrocarbons by a lipoxy-genase/hydroperoxide halolyase-mediated transformation in planktonic microalgae. J Am Chem Soc 128 7114-7115... 

Carlucci MJ, Pujol CA, Ciancia M, Noseda MD, Matulewicz MC, Damonte EB, Cerezo AS (1997) Antiherpetic and anticoagulant properties of carrageenans from the red seaweed Gigartina skottsbergii and their cyclized derivatives correlation between structure and biological activity. Int J Biol Macromol 20 97-105... 

The activity of extracts against microalgae has led to the isolation of a large group of simple phenylethyl amides and various indolylethyl amides (e.g., 27, 28). We have obtained some of these compounds also from limnic bacteria, and, although their activity is low, it seems plausible that they play a role in the competition of bacteria with microalgae for free surfaces, perhaps on seaweed or other sessile organisms. 

Abrupt temperature changes are easier to appreciate than long-term changes. El Nino events, which are the best examples of the first type, occur in Indonesian forests in synergisms with threatening by human activities (Curran 1999). The same probably occurs on coral reefe too, where El Nino warming causes the death of seaweeds and invertebrates, in particular corals, which are extremely sensitive to temperature variations. 

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