Some aspects of the ecology of strongylocentrotus droebachiensis in eastern Newfoundland

Himmelman, John H. (1969) Some aspects of the ecology of strongylocentrotus droebachiensis in eastern Newfoundland. Masters thesis, Memorial University of Newfoundland.

[img] [English] PDF (Migrated (PDF/A Conversion) from original format: (application/pdf)) - Accepted Version
Available under License - The author retains copyright ownership and moral rights in this thesis. Neither the thesis nor substantial extracts from it may be printed or otherwise reproduced without the author's permission.

Download (8Mb)
  • [img] [English] PDF - Accepted Version
    Available under License - The author retains copyright ownership and moral rights in this thesis. Neither the thesis nor substantial extracts from it may be printed or otherwise reproduced without the author's permission.
    (Original Version)

Abstract

Strongylocentrotus droebachiensis is the dominant macroscopic benthic animal along the exposed coasts of Newfoundland. The gonads ripen during the fall, reach a peak in size and maturity in February or March, and spawnout occurs by April. In exposed areas the density is very high (up to 350 urchins/m²) and small urchins are abundant. In sheltered areas the density is much lower but most of the individuals are large. The urchin populations are concentrated in shallow water where macrophytes, their main food, grow abundantly. Urchins have variable preferences for and abilities to consume different algae. Feeding is least in the winter, when the gonads are near their peak, and greatest following spawnout. The potential grasing rate is sufficient to restrict noncalcareous macrophytes to the sublittoral fringe where the abrasion of the gonads, as they are washed back and forth by waves, keeps the urchins from advancing and devouring them. Only Agarum cribrosum and Ptilota serrata, which are undesirable urchin foods, grow at greater depths in urchin dominated areas. Sea stars, other urchins, lobsters, crabs, a number of fishes, and birds are common predators of S. droebachiensis but are not very effective in limiting their numbers.

Item Type: Thesis (Masters)
URI: http://research.library.mun.ca/id/eprint/7107
Item ID: 7107
Additional Information: Bibliography: leaves 137-143.
Department(s): Science, Faculty of > Biology
Date: 1969
Date Type: Submission
Geographic Location: Canada--Newfoundland and Labrador, Eastern
Library of Congress Subject Heading: Sea urchins

Actions (login required)

View Item View Item

Downloads

Downloads per month over the past year

View more statistics