Category Archives: Sand beach

Field Lab on Wittys Lagoon used by Marine Science , Pearson Colloege

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This file represents one in a series of field labs which have been used by faculty members at Lester B. Pearson College.

The Witty’s Lagoon Estuary and Beach Field Lab
This lab is appropriate for an introductory level class in ecology. It may also serve as a reference for those planning field labs for other similar coastal ecosystems.

We will spend one week on this field lab. The actual field excursion is only a part of the whole package. We will go to the Witty’s Lagoon Beach and Estuary, where we will further develop the concepts of structure and function of ecosystems, interactions between ecosystems, geological evidence, adaptations to abiotic factors .

Background references:
Odum, Ecology, page 224-228
Sumich, Biology of Marine Life: p 119-124
Carefoot, Pacific Seashores–section on Dune Vegetation.
Section on Witty’s beach from the OIL SPILL TRILOGY:
CRD Coastal Management Booklet page 6 and 8.

 

Ecological Systems Interact: This is a feature of systems we have seen in some examples but it is particularly well represented here as there are many features of this area that provide valuable examples of systems operation and interactions.

HUMAN IMPACT:
Record all examples of how humans interact with the ecosystems here. Include these on your map. In class, get further evidence from the Oil Spill Trilogy video .

ON THE BEACH:
1. Note the bulkheading near the stairs. Diagram the effect of this type of structure on the stability of the beach.

2. Locate on the map the feeder bluff, make a diagram of the area to include this feature, indicate it’s relationship with the beach. Indicate the implication of human modification to this process.

3. From the maps available , the pictures in the CRD booklet and your observations, diagram the spit , showing the history of it’s development.

4. Show the direction of ocean energy impact and long shore drift. What would happen if a solid bedded roadway was built along the spit, especially close to the berm ?

5. Draw a cross sectional profile of the beach showing the foreshore, the berm, the backshore and the lagoon and the associated vegetation.

6. The strand line: Describe this feature and comment on the input of energy and materials to this part of the system .

7. The beach VEGETATION: Note and diagram the special adaptations of beach vegetation: What patterns of distribution do you note? and why?

8. How does diversity, and biomass change as you go from sea to land?

9. The grass here is the Dune Grass Elymus mollis.. It is one of the earliest colonizers of the beach area. Diagram the underground root system and comment on it’s role in contributing to beach stability.
10. Carefoot presents a model for the change in pH of the soil from sea to land. Take samples here for analysis back in the lab. Provide any evidence that you can on what effect this may have on the vegetation of the areas.
11. What types of impact do humans have on the vegetated part of the beach and what is the problem with this?

THE SALT MARSH and ESTUARY:
12. Vegetation succession in the SALT PANS. Compare the vegetation that you see here with that of the estuary vegetation in Pedder Bay. Note any differences and similarities. Explain why the vegetation is patterned in this way.
13. A Geological mystery?
Work done by previous students has shown there to be an “OLD” and a “NEW” sand beach . We will investigate this further by sampling from the sand on the beach , and samples from the estuary. We can return these to the lab to look at them in a quantitative way (using soil sieves). From your evidence, piece together the geological events of the past.
14. Use the soil probe to determine the vertical profile of the marsh. Diagram this to scale also. Comment on the geological history of the area.
15. Describe the types of human influence you can observe in this ecosystem.
16. What evidence is there of humans “managing “ this system . Would you consider it to be an ecologically sustainable system.
17. While on this trip, gather enough observational evidence and examples to make a four part systems diagram that shows energy flow and material cycles of four interacting ecosystems: estuary, spit, berm, beach,and ocean. Discuss and compare the level of productivity that you would estimate in each of the systems.

This site has been created to represent the contiguous ecosystems of the Race Rocks Ecological Reserve/Marine Protected Area and for the use of the Green Blue Spaces sub committee of the Metchosin Environmental Advisory Select Committee ( MEASC).
Copywrite: G.Fletcher Marine Education Consulting, 2008
webmaster: Garry Fletcher, educational director of racerocks.ca

Sector 7: Taylor Beach, Witty’s Lagoon and Albert Head

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Aerial views courtesy of the CRD NATURAL AREAS ATLAS

11..Witty’s lagoon/estuary and 10. Beach spitwittys

Witty’s beach is an accretional beach with materials supplied from long shore drift from the cliffs to the south. Behind the beach is a large tidal lagoon, and estuary fed by Bilston Creek.

 

Report on Witty’s lagoon (includes Ecology, geology etc. Waterose et al.

Link to the Witty’s lagoon Waterose et.al report

 

 

 

 

 

Link to the Anthropogenic Effects on this area

 

 

Link to The Wittys Lagoon Estuary and Beach Lab

The following booklet was written in the 1970’s based on the report done by Dr. Wolf Bauer.

A panorama view from the inside of the spit on Witty’s lagoon

A panorama view of the narrow channel for tidal exchange at the end of Witty’s Spit.

4.. Haystock Islands

Haystock Islands show some evidence of human occupation by First Nations in the past.

 

 

 

4.5,6,7.. Tower Point and Duke Road Waterfront
South of Albert Head

 

 

 

  • ** “You can also see excellent exposures of pillow lavas at Tower Point. On the Point and in the sea cliffs of nearby islands, the characteristic feature of the pillow basalts are well displayed in clean outcrops above the high tide line. These dark green, fine-grained rocks commonly contain amygdules filled with quartz and calcite, which appear as white spots up to 1cm in diameter. Several vertical, green vesicular dykes, up to 1 m. wide, trend across the point, and a minor east dipping fault is exposed on the western side of the point. Several outcrops display piles of basalt pillows with flattened bases and shapes that indicate they were squeezed together while the lava was still hot and plastic. You cans see conspicuous light grey to almost white boulders of granodorite, obviously (glacial) erratics, lying on the surface of the pillow basalts.”…..
  • “According to Nick Massey of the BC Geological Survey, the Metchosin Igneous Complex developed as an oceanic island, not unlike Iceland, about 54 million years ago. The pillow basalts exposed here as well as those at the Sooke Potholes… are only part of the complex….Many of the pillows seen in this area contain abundant, round white amygdules, which are commonly arranged in layers close to the margins of the pillows. These amygdules were originally vesicles that have been filled by crystals of calcite and other minerals. Vesicles form when gas, dissolved in molten lava separates from the liquid, causing it to froth. If the pressure of the weight of the overlying water is sufficiently great, the gas does not separate and no vesicles form. Thus there is a rough correlation between the depth below sea level at which the lava erupted and the vesicularity of the lava; with increasing depth, the degree of vesicularity decreases. From this relationship, we can conclude that the pillow basalts of the Metchosin Igneous Complex erupted in moderately deep to shallow water, but not as deep as the present Pacific Ocean Spreading Ridges.”
    2005, Yorath, Chris, The Geology of Southern Vancouver Island, page 114, Harbour Publishing.

 

5.South Side of Albert Head

 

 

 

 

4,. Albert Head and 2 and 3 North Lagoon and 1.Beach

 

 

 

 

To the north of Albert Head Beach and outside of the boundaries of Metchosin District lies the gravel pit which is now in the stages of being close down, to be replaced by a large development .

 

 

Anthropogenic habitat modification from Witty’s lagoon to the south side of Albert Head.

Acknowledgements:

Anthropogenic Impacts Albert head lagoon and shoreline

Helicopter aerial views courtesy of GEOBC

The CoastaMetchosin website has been created to represent the contiguous ecosystems of the Race Rocks Ecological Reserve/Marine Protected Area and for the use of the Green Blue Spaces sub committee of the Metchosin Environmental Advisory Select Committee (MEASC). Copyright: G.Fletcher 2013 (garryf ( use at) gmail.com)