7 replies to this topic

[cellfighter]

AOR has a new dietary supplement http://www.aor.ca/re...ch/fucoidan.php which as interesting as it is will probably kill you if you happen to get certain infections. I would love to see them add a disclaimer on the bottle.

[kylyssa]

Also, as slow growing plants that live twenty years or so in shallow, shore proximate waters steeped in pollutants Ascophyllum nodosum (the marine plant the supplement is made from) hangs onto heavy metals, lots of them.

Ascophyllum nodosum

Seaweeds are recognised as good indicators of heavy metal pollution as they readily take up minerals from the water and sequester them without processing or later discharge (in what is thought to be a passive uptake mechanism). Trials in the Cork area of Ireland have shown that Ascophyllum nodosum and Fucus vesiculosus are suitable species. Fucus vesiculosus has a particular propensity for zinc uptake and is therefore a useful biomonitor of this heavy metal. Age and condition of the plants used may have some influence on the amount of metals absorbed and it is not possible to compare different species (with different physiologies) directly.

Bibliographic reference: Cullinane, J. P., Doyle, T. M. & Whelan, P. M. (1987). Uses of seaweeds as biomonitors of Zinc levels in Cork harbour, Ireland. Hydrobiologia 151: 285 - 290.

In Scotland, a recent (1996) study was conducted on metal uptake of Ascophyllum nodosum from the Clyde estuary. Samples taken from 1964 to 1994 from three areas (Hunterston, Wemyss Bay and Ardneil Bay) were found to contain levels of metals which reflected changes in nearby heavy industry over time, as the factories and power stations discharged the metals into the Clyde.

Bibliographic reference: Molloy, F. J. & Hills, J. M. (1996). Long-term changes in heavy metal loadings of Ascophyllum nodosum from the Firth of Clyde, U.K. Hydrobiologia 326/327: 305-310.

Not only that but the expanded harvest of knotted wrack (Ascophyllum nodosum) is not a very environmentally sound proposal, especially for something of such dubious worth as a supplement.

A species undergoing rapid decline in Europe.

   
  

Ascophyllum nodosum (Linnaeus) Le Jolis
Family: Fucaceae
 
Knotted wrack is perhaps the best known of all the seaweed of Northern Ireland. Because of its large size and dominance, any danger to it is a danger to the life on the shore.
 
In brief

Very common on most rocky shores, except those most exposed to wave action

To be found on all rocky shores protected from strong wave action

Can be found at all times

Although common, it has undergone rapid decline which may be an indicator of changes in the habitat

No threats known, but any development or change on the shore or nearby coast will endanger it.


 
Species description
Ascophyllum nodosum is one of the most important seaweeds on the more sheltered shores. It is a large brown alga, which can grow to 2m long and live for several decades. The large egg-shaped air bladders occur in series along the frond making it easy to recognize. The frond is olive-brown in colour, somewhat compressed, thick and strap-like but without a mid-rib; it branches freely. ‘Hold-fasts’ attach it firmly to rocks and boulders. These hold-fasts simply attach the plant to the rock but unlike roots they do not in any way ‘feed’ the plant. The bladders are up to 5cm long and are not easily ‘popped’, but can be used by children to spray water or as whistles.
Ascophyllum nodosum commonly bears small tufts of what appears to be a parasitic alga, Polysiphonia lanosa, which is a small red alga that can grow to about 5cm long with dense branches and although it seems to be common on Ascophyllum it is rare elsewhere and is not a true parasite.
 
Life cycle
The diploid plants are dioecious and produce receptacles in which there are flask-like conceptacles containing male antheridia or female oogonia. When released, the sperm from the antheridia fertilises the eggs from the oogonia: they fuse, settle and grow to produce new plants.
 
Similar species
Fucus vesiculosus is a similar species as it also has air-bladders. However, in contrast to Ascophyllum, these are in pairs and on opposite sides of a mid-rib which runs along the centre of the flattened frond. Mature species of the genus Fucus are not as big as Ascophyllum although they can grow to nearly 1m in length. The air-bladders are much smaller than those of Ascophyllum.
 
How to see knotted wrack
Ascophyllum nodosum can be found all year round on most rocky shores, especially the more sheltered sea loughs such as Strangford Lough. However, it cannot withstand the more exposed conditions of headlands or steep rocky shores. Specimens found in sandy bays will be drift specimens of little interest, usually gnarled and weather-beaten.
The large brown algae on the more sheltered rocky shores grow in ‘zones’ along the shore. The species forming the top zone is Pelvetia canaliculata, lower down there is a zone of Fucus spiralis, lower still Fucus vesiculosus, near low water Fucus serratus and at very low water and below Laminaria digitata. On sheltered shores Ascophyllum grows along the middle of the shore competing with Fucus, especially F. vesiculosus.
 
Current status
A. nodosum is one of the most common seaweeds; however it seems recruitment is poor with slow growth of germlings which may suffer from grazing. As a dominating species it is important: any changes in its distribution or density may well have important implications.
 
Why is knotted wrack a priority in Northern Ireland?

It has undergone rapid decline.


 
Threats/Causes of decline
It is harvested in Ireland, Scotland as well as Europe and the populations may be under threat from over-exploitation or pollution in the sheltered inlets in which it thrives.

Conservation of knotted wrack

Current action

Strangford Lough is designated as a Ramsar, SPA, SAC, MNR and ASSI.



Proposed objectives/actions

Maintain the geographical range.



What you can do
Report any records to Osborne Morton, Botany Department, Ulster Museum, Botanic Gardens, Belfast BT9 5AB, Tel: 028 9038 3151, Osborne.morton@magni.org.uk. Report any coastal damage, for example, dumping, sediment removal, etc.
 
Further information
Links
AlgaeBase
http://www.marlin.ac.uk/
Further information on ASSIs
 
Literature
Guiry, M.D. and Blunden, G. (eds) (1991). Seaweed Resources in Europe: Uses and Potential. Johy Wiley and Sons.
Hardy, F.G. and Guiry, M.D. (2003). A Checklist and Atlas of the Seaweeds of Britain and Ireland. British Phycological Society, London.
Morton, O. (1994). Marine Algae of Northern Ireland. Ulster Museum, Belfast.
Morton, O. (2003). The Marine Macroalgae of County Donegal, Ireland. Bull. Irish Biogeographical Society 27: 3-164.
 
Text written by:
Osborne Morton, Curator of Botany, Ulster Museum

Edited by kylyssa, 30 September 2006 - 07:39 PM.

[jaydfox]

Interesting. Without further study, I can't really say whether the benefits outweigh the risks. More info is required. Perhaps it's already out there, but I'm too lazy to look it up. For me anyway, the info is not clear-cut enough to risk taking a supplement like this, unless I have a metabolic disorder that makes it more likely to be beneficial.

The AOR page discusses the 34 enzymes necessary to convert other sugars into fucose. So perhaps one's best bet for now is to hold off, unless one has had a metabolilc screening and knows for sure that they have a metabolic disorder related to deficiency of one or more of those 34 enzymes?

But is screening for fucose production a "standard" part of typical metabolic screenings? Or would one need to go to a specialty clinic?

[kylyssa]

Probably is. There's something else I plan to look up- as a marine aquaculturist I have experienced firsthand "chemical warfare" waged by marine plants when they are disturbed, cut, or fed upon - often the chemicals they release are quite nasty. I wonder what Ascophyllum nodosum releases under harvest stress conditions?

[ajnast4r]

call them, AOR is really open and always willing to talk. see what they have to say and report back

[kylyssa]

Actually, with a casual search I uncovered that the chemicals the plant iuses for its warfare may actually be the upside of this supplement!

They appear to be some form of polyphenolic phlorotannins which probably are quite upsetting to invertebrates but may be beneficial to those of us with spinal columns.

Whatever it's good for, we still need to be conscious of maintaining only sustainable harvests of wild product. This algae grows slowly and provides a habitat for many small marine creatures. In some ways it is akin to harvesting trees due to the long lifespan of the algae in question.

[mitkat]

Whatever it's good for, we still need to be conscious of maintaining only sustainable harvests of wild product.  This algae grows slowly and provides a habitat for many small marine creatures.  In some ways it is akin to harvesting trees due to the long lifespan of the algae in question.

Absolutely. Ascophyllum nodosum came up once in my studies while looking at possible invasive species in a martime climate, and your tree analogy is pretty much dead-on.

This seems like a bit of a niche product, and as much as I always want to buy everything AOR sells, it appears fairly specific and I don't need any more wonderdrugs solving problems I didn't even know I had until I pay to fix them.

[cellfighter]

Thanks for the feedback guys. I was hoping one of your moderators that works for AOR for reply though. Is he still around? I would love to see an open debate on this and see both sides of the issue.