114
A. D. BONEY
Algin (alginic acid) is the main constituent of the cell walls of
brown algae, located in the middle lamella and in the primary wall
(Kreger, 1962). The total alginic acid content of a plant varies with
depth of immersion and with the season (p. 201 et seq.). Two polymerizing units have been identified, D-mannuronic acid and L-guluronic
acid. Fucinic acid has also been reported present in some brown algae.
Two other extractives of importance are laminarin and mannitol.
Laminarin is of widespread occurrence in brown algae (Quillet, 1958)
and is in fact a mixture of polysaccharides. Mannitol, a polyhydroxy
alcohol, is a cell-sap constituent found in numerous brown algae, but is
now known to occur in other algal classes.
There is at present very little information on the detailed structure
of algin from different orders of the brown algae. Quantitative differences between the two polymerizing units have been reported for
the orders Dictyotales and Fucales (see Kreger, 1962). The identification of enzymes in marine invertebrates capable of breaking down
algin have been reported (Miwa, 1940; Eppley and Lasker, 1959; Galli
and Giese, 1959), and the bacterial degradation of algin is a180 reported (Chesters et al., 1956). An enzyme capable of hydrolyzing
laminarin has been identified in the giant chiton Cryptochiton stelleri
(MiddendorfF) (Meeuse and Fleugel, 1958). It is thus possible that
biochemical differences between brown algal reserves and products may
be detectable using specific enzymes, and a biochemical classification
be made for some orders of the Phaeophyceae, as already applied to the
red algae by Stoloff (1962).
IV. SEAWEED RESOURCES
The standing crop of any plant population may be defined as the
balance between the rate at which the plants have been growing and
the rate at which depopulation occurs. To assess the value of a harvestable crop there is clearly a need for quantitative estimates, and these
could also indicate any annual or cyclic changes in the available weed.
It is also desirable to know the extent to which regular harvesting
affects the standing crop.
A. Survey methods
Surveys of both intertidal and sublittoral marine algae are attended
by a number of difficulties, in the former due to accessibility, and in
the latter because of the tide rips and heavy swells which make boat
work a hazardous operation. Despite the difficulties a number of survey
methods have been applied with considerable success. Many of the
surveyors, however, have indicated their data to be in the nature of
A. D. BONEY
Algin (alginic acid) is the main constituent of the cell walls of
brown algae, located in the middle lamella and in the primary wall
(Kreger, 1962). The total alginic acid content of a plant varies with
depth of immersion and with the season (p. 201 et seq.). Two polymerizing units have been identified, D-mannuronic acid and L-guluronic
acid. Fucinic acid has also been reported present in some brown algae.
Two other extractives of importance are laminarin and mannitol.
Laminarin is of widespread occurrence in brown algae (Quillet, 1958)
and is in fact a mixture of polysaccharides. Mannitol, a polyhydroxy
alcohol, is a cell-sap constituent found in numerous brown algae, but is
now known to occur in other algal classes.
There is at present very little information on the detailed structure
of algin from different orders of the brown algae. Quantitative differences between the two polymerizing units have been reported for
the orders Dictyotales and Fucales (see Kreger, 1962). The identification of enzymes in marine invertebrates capable of breaking down
algin have been reported (Miwa, 1940; Eppley and Lasker, 1959; Galli
and Giese, 1959), and the bacterial degradation of algin is a180 reported (Chesters et al., 1956). An enzyme capable of hydrolyzing
laminarin has been identified in the giant chiton Cryptochiton stelleri
(MiddendorfF) (Meeuse and Fleugel, 1958). It is thus possible that
biochemical differences between brown algal reserves and products may
be detectable using specific enzymes, and a biochemical classification
be made for some orders of the Phaeophyceae, as already applied to the
red algae by Stoloff (1962).
IV. SEAWEED RESOURCES
The standing crop of any plant population may be defined as the
balance between the rate at which the plants have been growing and
the rate at which depopulation occurs. To assess the value of a harvestable crop there is clearly a need for quantitative estimates, and these
could also indicate any annual or cyclic changes in the available weed.
It is also desirable to know the extent to which regular harvesting
affects the standing crop.
A. Survey methods
Surveys of both intertidal and sublittoral marine algae are attended
by a number of difficulties, in the former due to accessibility, and in
the latter because of the tide rips and heavy swells which make boat
work a hazardous operation. Despite the difficulties a number of survey
methods have been applied with considerable success. Many of the
surveyors, however, have indicated their data to be in the nature of