The papers submitted herewith relate to personal researches on various aspects of the biology of phytoplankton principally in
Scottish freshwater lochs but also of the river plankton in the White
and Blue Niles in the Sudan. The latter studies were conducted as part of a programme of work on the fundamental hydrobiology of the
Nile initiated by Dr. J. Rzoska and the author, who together inaugurated
the Nile Hydrobiological Research Unit. An introduction to this work
is the systematic account of the algal plankton of both rivers (1) and
is based on collections made between 1949 and 1952 from the Blue Nile
at Khartoum and from many places between Khartoum and the Sudd region on the White Nile. Some of the effects, on the river's plankton and
hydro -chemistry, of impounding water above the Gebel Aulyia Dam on the
White Nile, south of Khartoum, were studied by taking a succession of
samples from the Dam upstream for 325 Km (2). It was found that the
plankton showed a numerical increase of more than 100 -fold, the increase
being; associated with the change from river -to lake -like conditions as the Dam was approached. The seasonal development of the plankton in
the White and Blue Nile has also been investigated (3). This study was based on regular samples collected over a period of three years, from
1951 -53, and indicates that although regular annual fluctuations in
plankton density occur in both rivers, their peaks do not coincide but show a marked dependance on the specific hydrological regimes of
the two rivers, which are briefly summarised. Related to these
studies on Nile algae are some observations on the ecology of the
terrestrial alga, Fritschiella tuberosa which makes a seasonal
appearance on drying mud on the banks of the Blue Nile (4.). Some
details of the exacting environmental conditions under which this
alga grows are presented. A comprehensive survey and bibliography
of the literature relating to the freshwater algae of Africa has also
been compiled (5).
The papers on the phytoplankton of Scottish freshwater lochs
have been assigned to three categories. These relate to studies: -
I. On water replacement in relation toe plankton productivity
(6). Here it has been shown that water inflow and outflow
in small lakes may be a factor of over -riding importance in
determining the abundance of plankton. This study is
related to the observations made on the White Nile plankton
at the Jebel Aulyia Dam (2).
II. On the effects on the phytoplankton of addin mineral
fertilizers to hill lochs (7 & 8), These studies which
are contributions towards investigations of the factors
affecting the biological productivity of Scottish freshwaters,
show that quite small additions of phosphate produce quite
profound and prolonged effects on the phytoplankton of the
treated lochs. Also bearing on this work are observations made on the aquatic fauna as an ecological factor
in studies of the occurrence of freshwater algae (9).
During the course of all these investigations
the phytoplankton of many lochs were examined and
observations made on this somewhat neglected aspect
of Scottish vegetation. These have been published
in a series of short papers (10 -14).
III. On the desmid- plankton which is especially prominent
in many Scottish lochs (15=22). This aspect of
phytoplankton research was begun in an attempt to use plankton algae as indications of the trophic status of
lakes (15 & 16). It was found, however, that the
taxonomy of the most commonly occurring genus, Staurastrum, was so confused that before any real progress could be
achieved a detailed reinvestigation would have to be made
of many of the supposedly well established, commonly
occurring species. Most prominent amongst these were
S. paradoxum and S. gracile, species which, according to
the literature are amongst the most widespread of plankton
organisms not only in the British Isles and Europe, but
throughout the world. An attempt has therefore been
made to rationalize the taxonomy of these two supposedly
cosmopolitan species (17 - 21). Studies have also been made on other desmids from the British freshwater
plankton again with special reference to the genus
Staurastrum (22 - 25).
(01) A systematic account of the phytoplankton of the Blue
and White Nile. Ann. Mag. Nat. Hist. Ser. 12, vol. 7,
195+, 648 -656.
|| (02) The influence of the Gebel Aulyia Dam on the development
of Nile plankton. J. Animal Ecol., 23, 1954, 101 -111+.
(with J. Rzoska).
|| (03) Seasonal plankton development in the White and Blue Nile near Khartoum. Verh. int. Ver. Limnol., 12, 1955,
327 -331+. (with J. Rzoska, and G.A. Prows.
|| (04) On the ecology of the terrestrial alga, Fritschiella
tuberosa, in the Sudan. New Phytol., 56, 1956, 130 -132.
|| (05) A bibliography of African freshwater algae. Rev. Algol.
1957, 207 -238. (with Ross, Kufferath & Sims).
|| (06) Some observations on the effects of water inflow and outflow
on the plankton of small lakes. J. Animal Ecol., 22, 1956,
22 -35. (with W.B. Woodward).
|| (07) Fertilization experiments on Scottish freshwater lochs.
I. Loch Kinardochy. Sci. Invest. Freshwat. Fish. Scot.
17, 1957, 30 pp. (with A.V. Holden).
|| (08) Changes in the phytoplankton of some Scottish hill lochs
resulting from their artificial enrichment. Verh. internat.
Ver. Limnol. XIII, 1958, 298 -305.
|| (09) The aquatic fauna as an ecological factor in studies of the
occurrence of freshwater algae. Rev. algol., (N.W.)
1, 1955, 11+1 -11+50
|| (10) Notes on some uncommon algae from lochs in the Tu.mmel -Garry
catchment area. Trans. bot. Soc. Edinb., 36 (3), 1954 -, 207 -211+.
|| (11) Notes on some uncommon algae from lochs in Kinross,
Perthshire and Caithness. Trans. bot. Soc. Edinb.,
1955, 309 -16.
|| (12) Notes on freshwater algae, mainly from lochs in Perthshire
and Sutherland, Trans. bot. Soc. Edinb., IL 1957,
|| (13) Notes on algae from the plankton of some Scottish freshwater
lochs. Trans. bot. Soc. Edinb., 37 (3), 1958, 174 -181.
|| (14) On some forms of Micrasterias new to or rare in Britain.
Naturalist, Lond., April -June, 1957, 37 -39.
|| (15) The status of desmids in the phytoplankton and the
determination of phytoplankton quotients. J. Ecol.,
4-7, 1959, 429 -445.
|| (16) The phytoplankton of some Irish loughs and an assessment of
their trophic status. Proc. Roy. Irish Acad., 60 B. (4),
1959, 167 -191. (with F.E. Round).
|| (17) Notes on desmids of the genus Staurastrum III. S. paradoxum
Meyen in the Jenner Herbarium of the British Museum.
Naturalist Lond., July -Sept. 1959, 81 -83.
|| (18) The published figures of the desmid Staurastrum paradoxum.
Rev. Algol. 4-, 1959, 239 -255.
|| (19) Staurastrum paradoxum Meyen and S. gracile Ralfs in the
British freshwater plankton, and a revision of the S.
anatinum - group of radiate desmids. Trans. Roy. Soc.
Edinb. LXIII No. 26, 1959, 589 -628.
|| (20) De Brebisson's determinations of Staurastrum paradoxum Meyen
and S. gracile,Ralfs. Nova Hedwigia, 1(2), 1959, 163 -166.
|| (21) The varieties of Staurastrum paradoxum Meyen - nomen dubium.
Nova Hedwigia, 1(4.), 1960, 431 -422.
|| (22) Notes on desmids of the genus Staurastrum I. S. pseudopelagicum,
S. subcruciatum, S. avicula and S. denticulatum. Naturalist,
Lond., July -Sept. 1957, 97-100.
|| (23) Notes on desmids of the genus Staurastrum. II. S. leptodermum,
S. longispinum, S. brasiliense, S. setigerum, S. clevei and
S. tohopekaligense var. trifurcata. Naturalist, Lond. July - Sept. 1958, 91 -95e
|| (24) Staurastrum pendulum var. pinguiforme Croasdale. S. micron,
West, f. major f. nov., fac. quadrata and S. micron var. perpendiculatum (Cronblad) nov. comb., desmids new to the British freshwater plankton. Nova Hedwigia, 1(2), 157 -162,
|| (25) Desmids from the plankton of some Irish loughs. Froc. Royl.
Irish Acad. B (6), 1958, 71 -91.