slow-growing compared to eukaryotic groups such as green algae. But once loaded with
nutrients, they can grow in the absence of external nutrients sources and can increase their
biomass from 4 32 times without further nutrient inputs. This opportunistic capability makes
them very successful competitors among the algae.
Control of biota in a lake can mean many things. When control is attained using
chemical means, decomposition of the eradicated organisms can demand oxygen and release
their nutrient content back to the lake. The elemental nutrient mass has been converted from a
utilized, bound form (biota) to a potentially available form. Because of these and other sources
of uncertainty, management of HABs remains unpredictable in outcome.
1.2.15.5 Future Outlook for HABs
Harmful algal blooms will continue in many lakes and aquatic systems where they
already exist. They will become more intense where long-term water quality trends allow them
to. At present there is no good predictive tool for management or planning for aquatic resource
utilization. Indeed, there is no good comprehensive survey for their distribution or prevalence in
the aquatic ecosystem. Further study of their effect has identified additional toxins produced by
the cyanobacteria and this study has accompanied the development of analytical tools for
identification of the algal strains responsible for certain toxins as well as for the toxins
themselves. There has been an increasing awareness of the importance of these organisms in our
aquatic resources.
1.2.15.6 Specific References
Anderson, D.M. and D.L. Garrison. 1997. Preface. Limnology and Oceanography 42 (5, part
2).
Chorus, I. and J. Bartram. 1999. Toxic cyanobacteria in water. A guide to their public health
consequences, monitoring and management. E. & FN Spon. London. 416 pp.
Codd, G.A. 1996. Harmful Algae News. IOC of UNESCO. 15:4.
Falconer, I.R., A.M. Beresford, and M.T.C. Runnegar. 1983. Evidence of liver damage by
toxin from a bloom of the blue-green alga, Microcystis aeruginosa. Med. J. Australia. 1:511.
Hayman, J. 1992. Beyond the Barcoo probable human tropical cyanobacterial poisoning in
outback Australia. Med. J. Australia. 157:794.
Howarth, R.W., R. Marino, and J.J. Lane & Cole. 1988. Nitrogen fixation in freshwater,
estuarine and marine ecosystems. 1. Rates and importance. Limnology and Oceanography 33:
619-687.
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