Daily Archives: Wednesday,December 4, 2002

Race Rocks Digital Herbarium–Archival reference

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Race Rocks Digital Herbarium

This Digital Herbarium was created by Ryan M.J. Murphy after his stay at the Race Rocks Marine Protected Area, in British Columbia.  This digital collection features images of over 40 species of marine algae found within the MPA, links to online Quicktime movies, a glossary, and classification information.  Not all species are identified. For these and other Macroalgae species, now see the Race Rocks Taxonomy.

The contents of this project have now been moved to the Race Rocks Taxonomy

Site Information

Race Rocks

Race Rocks in an archipelago situated at 48o17’45”N, 123o31’50”W, south of Vancouver Island in the Strait of Juan de Fuca.  A tidal range that exceeds 3m yields a large intertidal community that is constantly battered by large waves and subject to currents up to 6 knots.  The islands are surrounded by forests of Nereocystis luetkeana in the summer months, under which a highly developed subtidal community exists.

Study Features

Ryan Murphy used digital video equipment from Lester B. Pearson College and an hp digital camera to record the materials presented in this herbarium.  As Race Rocks is a Marine Protected Area, no live samples could be taken, thus necessitating this digital collection.  The author hopes that the benefits of this collection far outweigh the benefits of having brittle preserved samples stored away from public use.

Images and video were collected in the summer of 2002 with the help of Pearson College student Joe Downham.  Identification was completed by Ryan, Anne K. Salomon of the University of Washington, and Garry Fletcher of L.B. Pearson College.

Funding was provided to this project by the Leadership Mount Allison Academic Initiative.

Management

Race Rocks was declared a Marine Protected Area designate in October 2000.  It has been managed by Lester B. Pearson College since 1997.

Favourite Links

   https://www.racerocks.ca

   http://www.mta.ca/~iehrman/jalgaeholics/volume1number1.htm ( now not available)

   http://www.mbari.org

   http://www.algaebase.org

Contact Information

Ryan Murphy:

Garry Fletcher:

Project Supported By

   Lester B. Pearson College of the Pacific

Leadership Mount Allison

Dr. Irena Kaczmarska-Ehrmann

Anne K. Salomon

Garry Fletcher

 Joe Downham

Bibliography

Scagel, Robert F. (1972)  Guide to Common Seaweeds of British Columbia.  K.M. MacDonald Printing, British Columbia.

Halosaccion glandiforme: Sea sac –The Race Rocks Taxonomy

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halosaculva

 

Distinguishing Characteristics :
Typical descriptions of Halosaccion glandiforme depict the plant as a thin-walled elongated sausage-shaped sac found in the mid-intertidal region of rock dominated shores. The plant is identifiable by its rounded head and short stipe anchored by a small circular holdfast. It ranges in colour from yellow/brown to red/purple. Also, because of the water it contains, applying pressure to the plant produces fine sprays of water emitted from the pores. In Common Seaweeds of the Pacific Coast (by J. Robert Waaland) it is stated that “Halosaccion glandiforme may reach lengths up to 25 cm and 3 to 4 cm in diameter; typical sizes are about 15 cm long by 2 to 3 cm in diameter.” 

The following pictures were taken by Ryan Murphy, 2005

Domain: Eukarya
Kingdom: Protoctista
Division: Rhodophyta
Class: Rhodophyceae
Subclass: Florideophycidae
Order: Palmriales
Family: Palmariaceae
Genus: Halosaccion
Species: glandiforme (Gmelin) Ruprecht 1851
Common Name: sea sac

Biotic Associations:

Being an intertidal species Halosaccion glandiforme shares its ecological niche with several other intertidal dwelling species. Acrochaetium vagum, a different red algae, is an epiphyte to Halosaccion. Also such species as mussels, barnacles, and species from other algal divisions including Poryphera lancelota, and Fucus gardneri grow in the same vacinity of the intertidal zone as Halosaccion. Predation on the Halosaccion is limited, the most common source of predation is from molluscan grazers like the sea snail Tegula funebralis.

In a study done on Halosaccion at Bamfield Marine Station in 1983, Garry Fletcher found an association of microscopic nematodes dwelling inside the sac of intact Halosaccion. Also noted were the special aggregation of cells that formed the “holes” on the walls of the algae.These are not random pin holes but very specialized regions of the matrix of the water reservoir wall.

References and Sources of More Information:

Fletcher, Alex, INTERTIDAL ZONATION OF HALOSACCION GLANDIFORME: A FOCUS ON HEIGHT AND SLOPE AS FACTORS OF ZONATION, extended essay in Biology, 2002

Johnson, L.E. 1992. Potential and peril of field experimentation: the use
of copper to manipulate molluscan herbivores. Journal of Experimental Marine
Biology & Ecology, v160 n2, pp251-262.

taxonomyiconReturn to the Race Rocks Taxonomy and Image File
pearsonlogo2_f2The Race Rocks taxonomy is a collaborative venture originally started with the Biology and Environmental Systems students of Lester Pearson College UWC. It now also has contributions added by Faculty, Staff, Volunteers and Observers on the remote control webcams. Dec 2001–Alex Fletcher  PC.