Skip to main content
Download PDF
  • Published:

Recovery following experimental harvesting ofLaminaria longicruris andL. digitata in southwestern Nova Scotia

Helgoländer Meeresuntersuchungen volume 39, pages 83–101 (1985)Cite this article

Abstract

Laminaria population variables and understory community composition were monitored just prior to, and for two summers following, a September 1980 experimental total harvest ofL. longicruris De la Pylaie andL. digitata (L.) Lamouroux within two plots in Lobster Bay, Nova Scotia. Both plots, distinguished mainly by depth, were characterized by highLaminaria standing crop and no recent history of extensive sea urchin grazing. Within the shallower plot (2–3 m below MSL), recovery could not be assessed thoroughly due to ice damage, but within the deeper plot (3–4 m below MSL),L. longicruris regrew cropped biomass and attained maximum observed abundance within one year. BothLaminaria species required two years to mature to pre-harvest population characteristics. Survivorship of 0–1 year old and mature populations of both species was generally low (0–67 % per year); however, the higher maximum life expectancy ofL. digitata (> 4 years vs 2 years) can result in that species persisting to the disadvantage ofL. longicruris. Analysis of understory community composition for both harvested plots and their adjacent controls weakly distinguished the harvested plots one summer after harvesting from all others. It is doubtful the distinction is attributable to harvesting and in neither site was there evidence of a critical change in the understory community. Management implications for the commercial harvest of the brown algaLaminaria are discussed.

Literature cited

  • Breen, P. A. & Mann, K. H., 1976. Changing lobster abundance and the destruction of kelp beds by sea urchins. — Mar. Biol.34 137–142.

    Article  Google Scholar 

  • Chapman, A. R. O., 1981. Stability of sea urchin dominated barren grounds following destructive grazing of kelp in St. Margaret's Bay, eastern Canada. — Mar. Biol.62 307–311.

    Article  Google Scholar 

  • Chapman, A. R. O., 1984. Reproduction, recruitment and mortality in two species ofLaminaria in southwest Nova Scotia. — J. exp. mar. Biol. Ecol.78 99–109.

    Article  Google Scholar 

  • Cushing, D. H., 1973. Dependence of recruitment on parent stock. — J. Fish. Res. Bd Can.30 1965–1976.

    Google Scholar 

  • Foreman, R. E., 1977. Benthic community recovery and modification following intensive grazing byStrongylocentrotus droebachiensis. — Helgoländer wiss. Meeresunters.30 468–486.

    Google Scholar 

  • Gagné, J. A., Mann, K. H., & Chapman, A. R. O., 1982. Seasonal patterns of growth and storage inLaminaria longicruris in relation to differing patterns of availability of nitrogen in the water. — Mar. Biol.69 91–101.

    Article  Google Scholar 

  • Kain, J. M., 1975. Algal recolonization of some cleared subtidal areas. — J. Ecol.63 739–765.

    Google Scholar 

  • Kain, J. M., 1979. A view of the genusLaminaria. — Oceanogr. mar. Biol.17 101–161.

    Google Scholar 

  • Lüning, K., Chapman, A. R. O. & Mann, K. H., 1978. Crossing experiments in the non-digitate complex ofLaminaria from both sides of the Atlantic. — J. Phycol.17 293–298.

    Google Scholar 

  • Mann, K. H., 1973. Seaweeds: their productivity and strategy for growth. — Science, N. Y.182 975–981.

    Google Scholar 

  • Paine, R. T. & Vadas, R. L., 1969. The effects of grazing by sea urchins,Strongylocentrotus spp., on benthic algal populations. — Limnol. Oceanogr.14 710–719.

    Google Scholar 

  • Parke, M., 1948. Studies on the British Laminariaceae. I. Growth inLaminaria saccharina (L.) Lamour. — J. mar. biol. Ass. U. K.27 651–709.

    Google Scholar 

  • Pérez, R., 1970. Longévité du sporophyte deLaminaria digitata (L.) Lamour. — Revue Trav. Inst. Pêches marit.34 363–373.

    Google Scholar 

  • Pringle, J. D. & Sharp, G. J., 1980. Multispecies resource management of economically important marine plant communities of eastern Canada. — Helgoländer wiss. Meeresunters.33 711–720.

    Google Scholar 

  • Pringle, J. D., Sharp, G. J. & Caddy, J. F., 1980. Proceedings of the workshop on the relationship between sea urchin grazing and commercial plant/animal harvesting. — Can. tech. Rep. Fish. aquat. Sci.954 1–273.

    Google Scholar 

  • Shannon, C. E. & Weaver, W., 1949. The mathematical theory of communication. Univ. of Illinois Press, Urbana, 117 pp.

    Google Scholar 

  • Sharp, G. J., 1980. History of kelp harvesting in southwestern Nova Scotia. — Can. tech. Rep. Fish. aquat. Sci.954 1–273.

    Google Scholar 

  • Wharton, W. G. & Mann, K. H., 1981. Relationship between destructive grazing by the sea urchin,Strongylocentrotus droebachiensis, and the abundance of American lobster,Homarus americanus, on the Atlantic coast of Nova Scotia — Can. J. Fish. aquat. Sci.38 1339–1349.

    Google Scholar 

Download references

Author information

Author notes

  1. B. D. Smith

    Present address: Institute of Animal Resource Ecology, University of British Columbia, 2204 Main Mall, V6T 1W5, Vancouver, British Columbia, Canada

Authors and Affiliations

  1. Nova Scotia Department of Fisheries, Halifax, Nova Scotia, Canada

    B. D. Smith

Authors
  1. B. D. Smith
    View author publications

    You can also search for this author in PubMed Google Scholar

Rights and permissions

Reprints and permissions

About this article

Cite this article

Smith, B.D. Recovery following experimental harvesting ofLaminaria longicruris andL. digitata in southwestern Nova Scotia. Helgolander Meeresunters 39, 83–101 (1985). https://doi.org/10.1007/BF01997523

Download citation

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF01997523

Keywords

Helgoland Marine Research

ISSN: 1438-3888

Contact us