Tag Archives: chiton

Mist Maiden, Whimbrel and Gratitude

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This morning the wind was less than 10 knots and it was a beautiful time to be outside compared with the howling winds the last couple of days. It is from the west and increasing as the day goes on.

Often people ask me why I come to Race Rocks and this morning was a great reminder. As I cleaned the solar panels there was a soft west wind, the sun was in and out of the clouds as it rose in the east. Two California sealions were catching fish and shaking them as they surfaced. An eagle flew over and picked up a fish only to be chased ashore by two glaucous wing gulls. There are moments here when one is called to be present. There are many moments of frustration ( the electric fence is down again) and occasional fear (the wind, the geese) and boredom but then there are moments when one just doesn’t want to be anywhere else. And how often that does that happen in one’s life?

Visitors:

  • Pearson College had about 6 divers in Race Channel today but did not come ashore.
  • Just after noon now and 10 ecotourism boats have passed by

Observations:

  • Mist Maiden (Romanzoffia tracyi) is blooming!
  • I took a picture of the chiton shells and will post below. When walking around there are so many things that are taken for granted. Like the hundreds (thousands) of chiton shells. I suppose they are a stable food source. Has it always fed these birds? Did there used to be more fish skeletons? Sometimes it is good to record the obvious.

Work:

  • Cleaned the solar panels this morning
  • continued wheelbarrowing wood to house
  • cleaned out the wood stove
  • cleaning the house for Jill’s return
This female may be recognizable if this new puncture wound, upper right abdomen, leaves a scar

This female may be recognizable if this new puncture wound, upper right abdomen, leaves a scar

 

July 13 and 14 – Weekly Census

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Ecological Notes:

  • The sea lion population is growing. For the past few days there have been 18 Steller sea lions hauled out on Middle Rocks. That is up from four sea lions one week ago. One of the sea lions has a brand. It appears to say 620R, although the researcher I contacted in Oregon mentioned it is what they call a bad brand and he was unable to determine the brand from the photos I sent. I will keep a look out for the sea lion and see if I can get a better view. The researcher will check his records to see if he can identify the sea lion and be able to record the resighting.
  • The super moon on Wednesday night rose in the southeast at 10:00pm. It was a big bright orange orb that looked more like the rising sun, than the moon.
  • Today’s extremely low tide of -0.2m or -0.7′ was at 10:13am. The overnight high tide at 00:55am was 3.0m or 9.8′. It is apparently the lowest tide in a decade. I was fascinated to see the extended edge of the water all around the many islands. I looked at the exposed intertidal zone from a distance and up on the jetty, so as not to disturb the many delicate species.
  • See the photo gallery below for more ecological happenings from the past two days.

Weekly Census Results from July 13:

  • Steller/Northern sea lions: 18
  • Sea otter: 1
  • Harbour seals: 133
  • Bald eagles: 2 (1 juvenile and 1 adult)
  • Canada geese: 9 (5 adults, 4 goslings)
  • Black oystercatchers: 11 (8 adults, 3 chicks)
  • Cormorant: 4
  • Glaucous-winged gulls nesting on the main island: 247
  • Glaucous-winged gull chicks: approximately 200 (it is hard to get an exact number due to their camouflage in the grass and hiding under their parents)
  • Gulls not nesting (some glaucous-winged and some other species) on the south end of the main island and outer islands: 96
  • Pigeon guillemots: 142
  • Black turnstones: 2
  • Western sandpiper: 2

Weather:

  • Yesterday (July 13):
    • Sky: Part Cloudy
    • Wind: W 12-32 kts
    • Sea: rippled, then up to 3′ waves in afternoon and evening
    • Temperature Low 12oC, High 16oC
  • Today (July 14):
    • Sky: Part Cloudy
    • Wind: W 15-27 kts
    • Sea: rippled, then up to 2′ chop in afternoon
    • Temperature Low 11oC, High 13oC

Visitors:

  • No visitors

Facility Work:

  • Scrubbed and squeegeed solar panels, routine tidying and checking infrastructure around the island.

Vessel Traffic:

  • Many Canadian and American ecotour boats have been nearby and heading through the waters of the ecological reserve.

Here are photo highlights from the past two days. Click on the photos for larger views and captions.

Smoke And Fog Through The Week

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Weather:

  • Sky overcast, heavy fog and some smoke
  • Visibility 1 NM down to 100m
  • Wind 5-15 knots SW
  • Sea state: calm

Visitors/Boats:

  • A contractor came out to do a little work yesterday, and some supplies were brought over as well.
  • We have not had much other activity. Tour vessels are becoming less frequent, and the same for pleasure craft.

Observations: 

  • The fog and smoke cover has been extreme over the past four days or so – it is hard to discern the fog to smoke ratio. The fog horn has been sounding for the better part of those days. Probably an average of 16-18 hours per day and typically going through the night.
  • The sea lions are gradually taking over the shores of Race Rocks! Their numbers increase by the day – the areas around the ‘fuel shed’ and the crane are beginning to see a couple of curious creatures poking around. We’re planning on redesigning the fencing on the jetty for this season and for the rest of the island it looks to be high time for a parameter fence. We do need to keep the buildings protected and significant areas undisturbed, but it has been nice to see the sea lions lounge on the jetty.
  • There seems to be a bit of an increase in some birds. There have been shorebirds and others, perching all around the rock and often resting at night. If we need to move around outside at night we keep an eye out as they sleep in the grass and in the plants around the paths.
  • A census will come hopefully tomorrow – the visibility makes it into a game of opportunity.

Here are some pictures from around the rock over the past couple of days:

Bluebird Days

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Wind: yesterday 8-22 knots from E to N, today 4-17 knots from N in am and E to S in pm
Sea State: yesterday up to 1 m chop, today rippled
Visibility: both days 15 NM
Sky: both days clear
Temperature: yesterday 4-8 °C, today 5-9 °C
Atmospheric CO2: 413.53 ppm (recorded by NOAA at Mauna Loa Observatory, Hawaii)

The past two days have been clear. That’s four bluebird days in a row. The sunrises and sunsets have cast everything in a golden light. The views have been incredible of the snowy mountains in Washington State.

There hasn’t been much new activity with birds or mammals. One of the male elephant seals has joined the sea lion cuddle puddle near the crane.

Yesterday evening, a pod of orcas were swimming a few kilometres to the northeast. They appeared to be heading northeast, in the direction of Victoria. It could be the same pod from the previous evening.

There were nine visitors to the island yesterday. Five Pearson faculty and staff came in the morning to tour the island and discuss learning opportunities for Pearson students on Race Rocks. Alex, Ric and his friend came to do an upgrade to the electrical system controls.

The military’s demolition training on Bentinck Island concluded this morning.

Today, three tour boats were in the ecological reserve. Yesterday, there were two tour boats and two members of the navy in a small rigid hull inflatable.

UPDATED February 26: photos have been added now that the website is fixed.

Exciting Sightings

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Wind: yesterday 0-31 knots from W to E to N, today 10-17 knots from N-NE
Sea State: yesterday rippled, today rippled with chop up to 1 m in morning
Visibility: both days 10-15 NM
Sky: both days clear
Temperature: yesterday 5-7 °C, today 4-6 °C
Atmospheric CO2: 413.85 ppm (recorded by NOAA at Mauna Loa Observatory, Hawaii)

There were some exciting sightings over the past two days. Just before sunset this evening, a pod of orcas was swimming in the current to the west of the island. There were at least five or six orcas of various ages.

This morning, between 20 to 30 pigeon guillemots were paddling through the Middle Channel, to the north of the main island. Some still have grey-ish heads of their winter plumage.

Yesterday one tour boat, two sailboats and three pleasure crafts passed through the ecological reserve. Today three tour boats travelled by the islands. No visitors were on the island.

The military was doing demolition training for the past two days on Bentinck Island.

See the photos below for sights from the past two days:

Black Oystercatcher Nest!

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Weather

  • Visibility: 15 miles
  • Wind: 25-30 knots West in the morning
  • The rest of the day 15 knots West.
  • Sky: overcast
  • Water: 2′ chop

Ecological

  • Finally discovered a Black Oystercatcher nest!
  • 2 eggs are inside the “nest”.
  • Their nests are made of rocks and shells.
  • Census day.
  • I don’t seem to see any Black Turnstones or Surfbirds anymore.
  • Also less Bald Eagles.
  • And the Otter has been gone for a while.
  1. Harbour Seals: 117
  2. Northern Sea Lions: 32
  3. California Sea Lions: 22 (one branded U 687)
  4. Elephant Seals: 20 (17 on Great Race, 3 on Middle Rock)
  5. Seagulls: 327
  6. Pigeon Guillemots: 114
  7. Canada Geese: 21 (14 resident geese, 7 stopovers)
  8. Black Oystercatchers: 10 (plus 2 eggs!)
  9. Harlequin Ducks: 8 (6 males, 2 females)
  10. Cormorants: 4
  11. Barn Swallows: 2
  12. Bald Eagle: 1 immature
  13. Savannah Sparrow: 1

Maintenance

  • Rust painting.
  • More thistle weed whacking.
  • You can cut them down like you’re the Queen of Hearts, but they grow back.
  • Cleaned the solar panels.

Boats

  • Four or so eco-tours came by today.

More Wind, More Seal

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Weather

  • Visibility: 15 miles
  • Wind: 20-25 knots West, later 35-40!
  • Sky: mix of sun and cloud
  • Water: 2′ chop
  • Gale warning for tonight.
  • Should be less windy tomorrow.

Ecological

  • 17 elephant seals on Great Race. One more than yesterday.
  • I spied a few interesting chiton remains on the island today.
  • It looks like the birds were eating some gumboot and leather chitons.

E-seal with pink scrapes

Boats

  • Only one eco-tour today.

 

Katharina tunicata: The leather Chiton

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Katharina

Katharina tunicata the leather chiton

The black oystercatcher is the main predator of the leather chitons. at Race Rocks. We find chitons occuring abundantly in the lower intertidal zone . In the picture above they are located above a small cave in the intertidal zone on the West shore of Great Race. In order to withstand the heavy impact of waves and swell, they are able to clamp onto the rock tightly.    

Description:

Chitons are marine molluscs with oval shapes and shells divided into eight dorsal plates. The chiton Katharina lives in the medium intertidal region at Race Rocks. It is very abundant on the north and west shores of Great Race Rock.

Color:

Body to 12 cm long, elongate-oval ; all chevron-shaped shells are deeply embedded in girdle, exposed only in mid-dorsal area. The interior of valves is whiteas visible above. The girdle is thick and shiny, like black leather.

Life history:

Katharina feed on brown and red algae and on benthic diatoms which it rasps from the rocks. Young animals isolated in pools grow to a length of 15 mm in 1 year and 55 mm in 3 years. They reach sexual maturity at a weight of 4 gms (33-36mm). Spawning takes place from March to July depending on latitude, with the later spawning occuring in colder regions. The eggs are green and the life span seems to be about 3 years.

Classification:
Domain Eukarya
Kingdom Animalia
Phylum Mollusca
Class Polyplacophora
Genus Katharina
Species tunicata
Common name: Leather Chiton
Other Members of the Phylum Mollusca at Race Rocks.

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.  Original by Hameeduddin Mehri (PC yr 29)

 

 

Tonicella lineata: lined chiton–The Race Rocks Taxonomy

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Lined chitons are seen frequently by divers in the 5-15 meter depth at Race Rocks. Their color is highly variable, some being a turquoise colour while others are brown with white markings on some of the shell segments as noted on those in this video clip. Observe in particular, the patches of grazed Lithothamnion sp. , the pink encrusting algae.

 

Characteristics:

Tonos (stretched/braced) Cell, lineatus (lined/marked with lines).

The lined chiton eats the surface layers of this encrusting algae, including the film of diatoms and other small organisms on it.

All chitons have a muscular foot for locomotion, a complete digestive tract from the mouth to the anus, a calcium carbonate shell with 8 overlapping plates. This is produced by the mantle, where organs are suspended in coelom. A gill extracts oxygen and disposes waste, a chiton exposed to air consumes only 73 percent of the amount it does when submerged. It remains in oxygen debt until re submersion. Even though the body has bilateral symmetry, the gill numbers on both sides may very well be irregular, asymmetrical.

Physical Description: The lined chiton- Tonicella lineata -covered by 8 smooth plates,. Endless colour variations exist. The girdle around the plates is smooth and leathery, often with a row of lighter spots or bands. Size up to 5 cm long.


It is brightly colored, having a zigzagging dark black/ brown lines over a background of yellow, orange, pink, orchid, and lavender predominate. This aids in its camouflage around the Lithothamnion coralline algae, where it is usually found.
Geographical Range: Aleutian Islands to San Miguel Island, CA, Sea of Okhotsk, Northern Japan
Habitat: They live on rocks covered with coralline algae that are in the low intertidal or subtidal zone. They can also be found in urchin burrows in the rock.
Feeding: They eat encrusting coralline algae.
Predators:Predators of this invertebrate are sea stars, Pisaster ochraceus and Leptasterias hexactis. Harlequin ducks, and the river otters..
Reproduction: Dioecious broadcast spawners. Spawning occurs in the spring. The males release their sperm into the water while exhaling waste water. Females release a stream of green eggs. Larvae metamorphose into juveniles approximately 12 hours after having settled on coralline algae.
Adaptations: Larval development stops unless the larva settles on coralline algae, which is its food source. This alga also acts as camouflage, as the chiton is often of the same colour.

Possible Further Studies:
The behavior in different depths.
The reproduction cycle of the lined chitons.

Kingdom Animalia
Phylum Mollusca
Class Polyplacophora
Order Neoloricata
Suborder Ischnochitonina
Family Ischnochitonidae
Genus Tonicella
Species lineata
Common Name lined chiton

  • References:
    http://www.wallawalla.edu/academics/departments/biology/rosario/inverts/Mollusca/Polyplacophora/Tonicella_lineata.html

Ecology and reproductive biology of Tonicella lineata (Wood, 1815)(Mollusca-Polyplacophora), by JR Barnes, 1972

The larval settling response of the lined chiton Tonicella lineata, by J. R. Barnes and J. J. Gonor, MARINE BIOLOGY, Volume 20, Number 3, page 259-264, 1973

http://wikis.evergreen.edu/marinelife1011/index.php/Tonicella_lineata

Andy Lamb and Bernard P. Hanby, Marine Life of the Pacific Northwest, Harbour Publishing p. 176

Adam Sedgwick , Magazine: Proceedings of the Royal Society of London, Vol. 33, (1881 – 1882), pp. 121-127
Morris, R.H. et al. Intertidal Invertebrates of California. (Stanford: Stanford University Press, 1980)

Other Members of the Phylum Arthropoda at Race Rocks 
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.

 December 2001 – Bassam( Jarbawi (PC year 27)

 

 

Tonicella lineata: the lined chiton

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Characteristics:  Tonos (stretched/braced) Cell, lineatus (lined/marked with lines).
The lined chiton eats the surface layers of this encrusting algae, including the film of diatoms and other small organisms on it.
linedchiton-1
All Chitons have a muscular foot for locomotion, a complete digestive tract from the mouth to the anus, a calcium carbonate shell with 8 overlapping plates. This is produced by the mantle, where organs are suspended in coelom. A gill extracts oxygen and disposes waste, a chiton exposed to air consumes only 73 percent of the amount it does when submerged. It remains in oxygen debt until re submersion. Even though the body has bilateral symmetry, the gill numbers on both sides may very well be irregular, asymmetrical.

Physical Description: The lined chiton,  Tonicella lineata  is covered by 8 smooth plates,. Endless colour variations exist. The girdle around the plates is smooth and leathery, often with a row of lighter spots or bands. Size up to 5 cm long.


It is brightly colored, having a zigzagging dark black/ brown lines over a background of yellow, orange, pink, orchid, and lavender predominate. This aids in its camouflage around Lithothamnion,  the coralline algae, where it is usually found.
Geographical Range: Aleutian Islands to San Miguel Island, CA, Sea of Okhotsk, Northern Japan
Habitat: They live on rocks covered with coralline algae that are in the low intertidal or subtidal zone. They can also be found in urchin burrows in the rock.
Feeding: They eat encrusting coralline algae.
Predators:Predators of this invertebrate are sea stars, Pisaster ochraceus and Leptasterias hexactis. Harlequin ducks, and the river otters..
Reproduction: Dioecious broadcast spawners. Spawning occurs in the spring. The males release their sperm into the water while exhaling waste water. Females release a stream of green eggs. Larvae metamorphose into juveniles approximately 12 hours after having settled on coralline algae.
Adaptations: Larval development stops unless the larva settles on coralline algae, which is its food source. This alga also acts as camouflage, as the chiton is often of the same colour.

Kingdom: Animalia
Phylum: Mollusca
Class: Polyplacophora
Order: Neoloricata
Suborder: Ischnochitonina
Family: Ischnochitonidae
Genus: Tonicella
Species: lineata
Common Name:  lined chiton

Interesting Possible Further Studies:
The behavior in different depths.
The reproduction cycle of the lined chitons.

  • References:
    http://www.wallawalla.edu/academics/departments/biology/rosario/inverts/Mollusca/Polyplacophora/Tonicella_lineata.html    Ecology and reproductive biology of Tonicella lineata (Wood, 1815)(Mollusca-Polyplacophora), by JR Barnes, 1972The larval settling response of the lined chiton Tonicella lineata, by J. R. Barnes and J. J. Gonor, MARINE BIOLOGY, Volume 20, Number 3, page 259-264, 1973http://wikis.evergreen.edu/marinelife1011/index.php/Tonicella_lineataAndy Lamb and Bernard P. Hanby, Marine Life of the Pacific Northwest, Harbour Publishing p. 176Adam Sedgwick , Magazine: Proceedings of the Royal Society of London, Vol. 33, (1881 – 1882), pp. 121-127
    Morris, R.H. et al. Intertidal Invertebrates of California. (Stanford: Stanford University Press, 1980)

Other Members of the Phylum Mollusca at Race Rocks.

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.

Bassam Jarbawi (PC yr. 27)