The next shoreline outing will be our first estuarine outing.
When: 9:30-11:30 am, Thursday, September 26th. (3.5 foot low tide is 10:15)
Where: Meet at the the end of Carey Place in Royston
What: Surveying the algae, plants and invertebrates around the Trent River Estuary.
Carpool: if looking to carpool, we’ll leave at 9:15 from the old thrifty’s parking lot in downtown Courtenay
Prereading: If interested, shoreline member Betty Brooks and co. put together a marvelous report on life in the Trent river delta and estuary for the Canadian Wildlife Service. This is comprehensive in terms of Birds, Invertebrates, Algae and Plants. I’ll try and repurpose portions into a checklist before we go. Perhaps there has been changes in the intervening 32 years.
Safety Precautions: Boots are advised. Access is via a relatively level trail. Shoreline is level with small pebbles and sand.
See you soon,
At our last gathering at Seal Bay on September 9th we were not disappointed in the array of botanical forms : flowers in still bloom, including the musk-flower- Erythranthre moschata ( yellow monkey flower with slimy leaves) and the abhorred purple loosestrife, Lythrum salicaria!; many plants with their seedheads; a variety of fungi including the dying Russula nigricans parasitized by Asterophoros lycoperdoides, then colonized by a blue mold. The highlight was Randal’s pointing out baby ferns – the tiny heart-shaped new sporophytes on the shaded underside of logs beside the trail (which of course challenged the focus settings of my camera).
Our next gathering will be on Monday October 7th, at Paradise Meadows in Strathcona Park to see all the vaccinia and other shrubs in their splendid fall colours. We will also in the course of touring the meadows collect the SWI Plant signs in advance of the winter snows. Confirmation of the time for carpooling from the foot of the mountain will be circulated later.
The last good tide of summer hits next week. Ian and Dianna suggested Seal Bay sensu stricto as a summer destination, so lets give that a try.
Where: Seal Bay Park, Seabank Road Entrance (link to google map). Meet at entrance.
When: August 28th, 9:30am.
What: Intertidal life, starfish wasting survey
Packlist: rubber boots or footwear you can get wet, field guide, bucket, trowel, camera, pencil, clipboard. Sun protection– hat, sunglasses & sunblock.
Warnings: Shoreline can be rocky, uneven and slippery in places. Path walk down in a little steep near the end.
See you soon,
We had a great outing yesterday at the Willow Point Reef just south of Campbell River. Endless thanks to Sandra Milligan from NIC for leading the group and knowing this shoreline inside and out. We got to see an octopus den and a diversity of life (82 species) greater than any encountered thus far since the inception of the shoreline group. A species list follows at the end, varying little from what Sandra provided the group. My photo observations have been posted to CVN Shoreline iNaturalist Page. Please add your photos and observations if you feel so inclined. Pictures, comments and meandering notes follow below.
Keystone to Barestone: The Visible Consequence of Starfish Wasting Disease
One of the things that Sandra showed us was the direct consequences to shore life when a keystone species is suffering. In this case, the keystone species was the Purple Sea Star (Pisaster ochraceus), a prominent predatory echinoderm. The wasting disease that we have seen in action has reduced numbers of this species as well as other asteroids (yes, that is a technical name for sea stars and their relatives). At the Willow Point Reef, this has led to a population boom in a species that they prey on. We saw thickets of purple and green sea urchins (pictured above) occupying relatively bald sandstone bedrock. Sandra pointed out that these regions were formerly covered in the large kelp Alaria. Graceful as this winged kelp is to us, it is tasty to the urchins who are free to prey on the kelp as their population explodes absent the controlling presence of the sea stars. Sandra mentioned the voids left by Alaria and the rich kelp beds in the area are being filled by Sargassum, that bulby invasive brown seaweed.
Gumboot Chitons Everywhere
Despite its presence on Sandra’s species list, few of us expected to see so many big gumboot chitons filling the cracks and hugging the sandstone. The largest was somewhere north of 12 inches. This is a species that is hard to see on the shoreline. They spend most of the year in under the lowest tide line, moving up to exposed shore only to breed. This species, like most intertidal chitons is a “cow” (Sandra’s term for herbivorous grazers), consuming algae big (kelps) and small (diatomaceous crusts). Their enormous size does not happen overnight. Encased within the stubbly encompassing girdle are the same plates common to all chitons. These plates mineralize during regular, annual growth phases. Scientists can count the rings of growth in the plates much like the rings in of a tree to determine their age. It turns out they can live up to 40 years.
Colourful corals of Campbell River
Betty had mentioned being able to see corals on the shoreline in places on the island, but the point in front of the Panago seemed an unlikely place to find them. Happy little orange scleractinian corals (Balanophyllia elegans) ridged with calcite were spotting the ledges on the underside of the sandstone. Unlike most corals, it lacks symbiotic dinoflagellates/algae in its tissues, so it relies exclusively on indiscriminately stinging and capturing small creatures and floatsum that passes by its many tentacles.
Dead Man’s Fingers- The best common name
The deep forest green of Codium fragilis (above) was a surprise to see in our region. This large, three-dimensional and dichotomizing green algae is one of a number of vastly different species that go by the common name “dead man’s fingers”. I’m beginning to think that different cultures have different ideas about the look of a dead man’s finger. These ones come straight out of a Dr. Seuss book, The flavourful shrub Decaisnea seems to dwell in a purplish hue on the spectrum, whilst those of those of the fungus Xylaria polymorha must represent advanced decomposition. This is an introduced species.
Clionid Sponges and Giant Rock Scallops
Sandra showed us two really good examples of shell degradation by the activity of a tiny little sponge, Cliona. On the surface of both the Giant Rock Scallop (pictured above left) and the Hornmouth Snail (above right), we could see that the original mineral surface of these molluscs has been bored and thinned by the activity of Cliona. Excavating mineralized shell surfaces micrometers at a time by secreting enzymes to dissolve and loosen particles, this species is responsible for a lot of breakdown in the intertidal. While the pace might be slow, the product is voluminous. Carbonate mud (tiny particles of calcite) is produced by this activity. In the fossil record, we can see beds meters and meters thick composed almost exclusively of particles loosed by the activity of the “boring” sponges. Sandra mentioned the sponge as a pest from the perspective of aquaculture operations as it degrades the quality of oysters.
Honeycomb weathering or Bioeroders?
A number of shoreline members commented on the similarity of large cylindrical-to-hemispherical excavations at in the sandstones if Willow Point to patterns seen in shoreline sandstones on Hornby, Saltspring, Galiano and any number of other places where these rocks are found in proximity to the sea. There was mumblings of the word _Tafoni_, a term used to describe a type of honeycomb weathering in our area. To clarify: Honeycomb weathering happens above the hightide line to sandstones that are exposed to salt spray from the sea. The excavations that we were seeing in the sandstones at Willow Point were subtidal and were produced by the activity of invertebrates, most likely the sea urchins.
Species list. Modified barely from Sandra’s list based on what was seen and a few taxonomy changes. Please email me with corrections, additions and deletions. These are the things I remember seeing but between the 20 of us, there was likely more.