If one goes to the CRD Natural Areas Atlas and uses the measurement tools, you can find out some interesting facts about the extent of Metchosin’s Coastline.
The total land based shoreline of Metchosin : 48,660 metres (48.6 km)
Total length of shoreline around islands off Metchosin’s shore:
23,118.5 metres (23 km)
Total length of the shoreline of the Race Rocks Islands: 3500 metres. (3.5 km)
The Metchosin Environmental Advisory Select Committee of Metchosin District submitted this report to Council in June 2013.
See the complete report as a PDF: Metchosin Shoreline Report 2013June 10-2
Executive Summary
The unique values attributed to the Coastal Areas of Metchosin have been recognized both historically and by outside researchers. They have also been outlined at length in the Official Community Plan and other documents produced for the District.
The objective of the Metchosin Shoreline Report is to provide Mayor and Council with a background document and decision-making tools for issues related to Metchosin’s shoreline environment: the jurisdictional boundaries are delineated; examples of ecologically sensitive areas are highlighted; and the biological and geographical values of eight zones of the forty-five km of shoreline are profiled.
The values of biodiversity, education, natural capital, aesthetics, philosophy, and ecotourism are all affected by our coastal areas. Therefore, the risks from human activity on the sustainability of these areas are emphasized.
With the increasing likelihood of changing climatic events impacting on our shoreline, and in order to mitigate these risks, a number of recommendations are proposed for the Municipality to implement:
See the complete report as a PDF: Metchosin Shoreline Report 2013June 10-2
Metchosin BioBlitz Observations by Garry Fletcher and Sandra______on April 27, 2013 on the floodplane and estuary of Gooch Creek, on the 4645 William Head Road Property.
Sometimes viewed as a nuisance for boaters around the shores of Metchosin, kelp beds (Nereocystis luetkeana) are however a valuable species of our natural capital
Nereocystis luetkeana, Bull kelp
Our kelp beds provide ecosystem services such as habitat for juvenile fish, and marine mammals. Research on macroalgae of the temperate coastal areas in the world has also shown extremely high rates of photosynthetic capacity and therefore another ecosystem service, in these algal beds, carbon fixation, In this post I will annotate some of the significant research that documents the value of this resource.
“Kelp forests occur in cold, nutrient-rich water and are among the most beautiful and biologically productive habitats in the marine environment. They are found throughout the world in shallow open coastal waters, and the larger forests are restricted to temperatures less than 20ºC, extending to both the Arctic and Antarctic Circles. A dependence upon light for photosynthesis restricts them to clear shallow water and they are rarely much deeper than 15-40m. The kelps have in common a capacity for some of the most remarkable growth rates in the plant kingdom. In southern California, the Macrocystis can grow 30 cm per day.”
Abstract: There has been a good deal of interest in the potential of marine vegetation as a sink for anthropogenic carbon emissions , (Blue Carbon). Marine primary producers contribute at least 50% of the world’s carbon fixation and may account for as much as 71 percent of all carbon storage. In this paper, we analyze the current rate of harvesting of both commercial and growing and wild growing macro algae, as well as their capacity for photosynthetically driven carbon dioxide assimilation and growth. We suggest that carbon dioxide acquisition by marine macroalgae can represent a considerable sink for anthropogenic carbon dioxide emissions and the harvesting and appropriate use of macroalgal primary production could play a significant role in carbon sequestration and amelioration of greenhouse gas emissions.
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Sea Lettuce, ( Ulva lactuca)
Off the shores of Weir’s Beach grows a large bed of Sea lettuce (Ulva lactuca) . the following article attests to the efficiency of sea lettuce in carbon dioxide fixation:
Kaladharan, P and Veena, S and Vivekanandan, E (2009) Carbon sequestration by a few marine algae: observation and projection. Journal of the Marine Biological Association of India, 51 (1). pp. 107-110
Abstract: CO2 sequestration by the marine planktonic microalgae Nannochloropsis salina and Isochrysis galbana as well as macroforms Gracilaria corticata, Sargassum polycystum and Ulva lactuca was estimated under laboratory conditions. The green seaweed U. lactuca registered 100% utilization of CO2 towards carbon fixation from the ambient water up to 15 mg/l and beyond that it declined to 60%. The microalgae were able to utilize 27.7% of dissolved CO2 at 15 mg/l, but did not show any effect either for carbon fixation or for emission at lower and higher levels. Gross primary productivity of these algae were also not affected by increase in the CO2 levels. It is estimated that the seaweed biomass along the Indian coast is capable of utilizing 9052 tCO2/d against emission of 365 tCO2 /d indicating a net carbon credit of 8687 t/d.
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Concerns for the Kelp Resources of Metchosin:
Both the stipe and the blades of Nereocystis luetkeana are used for fresh and dried foods, nutritional supplements, cosmetic products such as exfoliants, fertilizers, animal feed, dog snacks, and dog shampoo and moisturizer. Producers have found that it is rich in calcium, magnesium, sodium, iodine, potassium, phosphorus, iron, bulk fiber, and vitamins A, B complex, C, D, E, and K, protein and free amino acids. It is used as an herbal remedy, with claims that it detoxifies body tissues of heavy metal and radioactive agents, treats thyroid disorders, arthritis and digestive problems; purifies blood, aids in weight loss, eases lymphatic swelling; treats herpes infections, eases inflammation and neuritis, soothes mucuous membranes, and reduces side effects of chemotherapy and radiation. Other benefits mentioned for Nereocystis luetkeana in the spa include that it is stimulating, firming, revitalizing, tonic and slimming. Over 25 products have been identified from over 10 different sellers in Canada, the United States, and the Netherlands.
Commercial harvesting is known to occur in British Columbia and California
As Nereocystis luetkeana grows in the subtidal and shallow intertidal zones, it is typically harvested from a skiff or small boat with a knife, although in some areas it may be harvested on foot at low tide.
Nereocystis tends to grow in large kelp forests, and the blades create lush surface canopies. Kelp forests provide important sheltering habitat for many marine fishes and invertebrates, including urchins, sea stars, snails and crabs, and are an important food source for sea urchins. These forests also provide habitat for sea otters since sea otters eat the invertebrates that live on the kelp forest floor and the kelp itself provides a canopy which the otter can anchor to while resting to keep from drifting away. The anchoring holdfast can reach a diameter of more that a foot, and can harbor its own collection of organisms by offering them protection among the haptera. Nereocystis luetkeana is the only kelp which will drop spore patches, so that the right concentration of spores lands near the parent’s holdfast. They grow out continuously from a meristem located at their base and slough off at their older outer tips. The detritus formed by the sloughing tips has been shown to be an important source of carbon for inshore intertidal communities. This detritus feeds species such as Blue rockfish (Sebastes mystinus) and many of the filter feeders, such as Pacific Blue Mussels (Mytilus trossulus) in the intertidal zone. Urchins feed on Nereocystis luetkeana, and conversely this kelp can opportunistically and rapidly colonize areas that have been cleared by urchins.”
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Research into the role of marine algae and its importance in contributing to energy flow when they end up on a beach is reported in the following research out of the Bamfield Marine Station:
The images for this slideshow from Beecher Bay to Albert Head were provided by GeoBC. Enlargements of each picture and captions may be seen in the Gallery
The PDF of this report from 2007 may be viewed in it’s entirety here:
Blue-green-spaces-Document
Note in particular: page 4 : TYPES OF GREEN and BLUE SPACES
part 5. Marine Areas.
a. Nearshore marine areas: These areas occur along the coastlines of Metchosin. They are productive nursery areas and habitat for marine life, and include eelgrass beds, kelp beds, and subtitle rocky areas.
b. Marine shorelines: these are areas of natural shoreline on land. They are an important part of the scenic character of the community, contain recreational trails or beach access points, and provide a buffer between buildings and natural dynamic processes such as shoreline erosion. Examples include rocky marine shorelines and beaches [especially between Helberg had and church island], tidal lagoons, estuaries and offshore islands.
Under recommendations —Municipal governments:
Link: The CRD Blue-Green report
Great Race Rock, the central island. All but the tower envelope is included now in the Race Rocks Ecological Reserve.. The other islands of the ecological reserve are represented below: The link to the racerocks.ca website is used for the ecological information on this part of Metchosin’s coastline.
Link to the Ecology of Race Rocks through the racerocks.ca website
Race Rocks Ecological reserve from Mount Blinkhorn
Race Rocks from Mount Macdonald
Race Rocks from the mouth of Pedder Bay
Race Rocks from Sea Bluff Trail
The MetchosinCoastal web 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).
Copyright: G.Fletcher 2013 (garryf(use at) gmail.com)
There are several areas along Metchosin’s coastline where there are beds of the two species of sea grasses.
Eelgrass : Zostera marina: http://www.racerocks.com/racerock/eco/taxalab/2006/zosteram/zosteram.htm
See this map, for locations of eel grass meadows, at #5 (off Taylor Beach) and # 12, (behind Swordfish Island)
Surf Grass: Phyllospadix scouleri : http://www.racerocks.com/racerock/eco/taxalab/phyllospadix.htm
Surf grass is most common on the West shore of Race Rocks (#11) and Church Island (#12)
The Coastline of Metchosin is not as protected as the inner shores of the Victoria to Sidney area. Eelgrass needs protection and thus is minimally important in our area as fish habitat compared to the macro-algal kelp beds.
The following reference details the work done on the mapping of sea grasses in other areas of lower Vancouver island:
From: Island Trust Fund E-News Update March 27, 2013
Seagrasses form large meadows that serve as nursery habitat and a refuge for juvenile fishes. The leaves serve as a cornerstone for the marine food web, supplying nutrients to salmonids and other fish, shellfish, waterfowl and about 124 species of faunal invertebrates.
Eelgrass habitats within the Salish Sea provide the basis for the region’s commercial and recreational fisheries revenue. The productivity of native seagrasses rivals the world’s richest rainforests.Eelgrass habitats capture and store large amounts of carbon at much more efficient rates than terrestrial forests. Scientists estimate the salt marshes and seagrass meadows of B.C. sequester the equivalent of the emissions of some 200,000 passenger cars.
Contaminates and shoreline development put pressure on fragile eelgrass meadow ecosystems. To protect eelgrass, we need to know where it is. We’re mapping eelgrass habitat so that we can better plan our strategies to conserve these valuable underwater ecosystems
The Islands Trust Fund is mapping nearshore eelgrass habitat in the Strait of Georgia and Howe Sound, in partnership with SeaChange Marine Conservation Society and the Seagrass Conservation Working Group.
Eelgrass Mapping Completed
Additional Technical Reference :
Mapping of Eelgrass (Zostera marina) at Sidney Spit Marine Park, Gulf Islands National Park Reserve Using High Spatial Resolution Remote Imagery: by Jennifer D. O’Neill BSc, University of Victoria, 2006:
ABSTRACT: The main goal of this thesis was to evaluate the use of high spatial remote imagery to map the location and biophysical parameters of eelgrass at Sidney Spit Marine Park, part of the Gulf Islands National Park Reserve. To meet this goal, three objectives were addressed: (1) Define key spectral variables which provide optimum separation between eelgrass and its associated benthic substrates, using in situ hyperspectral measurements, and simulated IKONOS and Landsat 7ETM+ spectral response; (2) evaluate the efficacy of these key variables in classification of the high spatial resolution imagery, AISA and IKONOS, at various levels of processing, to determine the processing methodology which offers the highest eelgrass mapping accuracy; and (3) evaluate the potential of ―value-added classification of two eelgrass biophysical indicators, LAI and epiphyte type.
| This list does not necessarily include all ecologically sensitive areas. Arguments could be made for the complete coastline being ecologically sensitive. | |
| 1.Lagoon with shorebird habitat, Sensitive dune vegetation on sand shore.2.Coastal Islands with harbour seal haulouts 3.Harbourseal haulout 4.Coastal lagoon, migratory and resident seabird habitat. 5.Eel grass beds offshore. Sensitive dune vegetation on sand shore. 6. High current invertebrate community 7. Estuary, mudflat habitat for overwintering shorebirds. 8. Cormorant winter roosting colony. 9. Kelp bed for fish spawning and seabird habitat. Great blue herons often feed from the kelp 10. High current channel with harbour seal haulouts and winter feeding grounds for seabirds, some migratory. Western Grebes and Buffleheads frequent the area in winter. 11. High current area, with significant invertebrate colonies, 12. Island ecosystems, swept with strong currents bearing significant invertebrate colonies. 13. Island ecosystems with significant invertebrate and kelp beds. |
Beecher Bay with marina from the north end at east Sooke Road. (Click for large panorama image)
Aerial Map Courtesy of the CRD NATURAL AREAS ATLAS
AREA1: Swordfish Island to Bedford Island.
AREA 2: North West corner of Beecher Bay
AREA 3: Islands in Beecher Bay
AREA 4: East Side of Beecher Bay and IR#2
AREA 5: North East Corner of Beecher Bay
See this file for the Anthropogenic effects of habitat modification
