Tag Archives: sea urchin

Not a Fun Day to be a Sea Lion!

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Another epic day!

 

 

 

 

 

 

This morning I spotted the darker of our two new otters feeding off South Island again. These two might need names if they keep sticking around. Bright red urchins were on the breakfast menu for today, personally I prefer a few less spikes with my coffee.

 

 

 

 

 

 

 

The afternoon brought transient killer whales past the reserve who spent 2.5 hours in the area hunting sea lion. While they didn’t come super close, they did put on a pretty unbelievable show!

 

 

Visitors:

  •  Greg and furnace repairman

Facility Work:

  • Keeper’s house furnace now working!
  • Prepped student house for visitors

Noted Vessel Traffic:

  • Ecotourism vessels

Weather Events:

  • Friday, March 15:
    • Sky: Blue sky
    • Wind: High of 14 knots, Low of 6 knots
    • Sea: Whitecaps
    • Temperature: Low 6oC, High 10oC

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.

July 11 and 12

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Ecological Notes:

  • I believe most of the gulls eggs have hatched, based on the nests I can see with one to three chicks and discarded empty eggs nearby. The gull parents feed fish to their young. I am impressed how many whole little fish a gull catch then regurgitate for their chicks.
  • I am seeing more nursing harbour seals and pups around the south and east sides of the island. Today, I heard a pup communicating with its mother by little grunting sounds.
  • This afternoon, out of the corner of my eye, I saw a river otter scurry along a path by Tank Shed. I could not see if it was heading for the water or underneath the boardwalk, as they are elusive.
  • See the photo gallery below for more ecological happenings from the past two days.

Weather:

  • Yesterday (July 11):
    • Sky: Clear
    • Wind: W 1-33 kts
    • Sea: rippled, then 2′ chop in evening
    • Temperature Low 11oC, High 20oC
  • Today (July 12):
    • Sky: Clear, fog between 08:45-09:30 with foghorn
    • Wind: W 16-39 kts, gusts up to 44 kts (81 km/h)
    • Sea: 1′ chop in morning, then up to 4′ waves in afternoon and evening
    • Temperature Low 12oC, High 15oC

Visitors:

  • Yesterday, Greg came from the college to refill the diesel tank.

Facility Work:

  • Scrubbed and squeegeed solar panels, routine tidying and checking infrastructure around the island. With the clear days, the solar panels have been fully charging the batteries.

Vessel Traffic:

  • Many Canadian and American ecotour boats have been nearby and heading through the waters of the ecological reserve. There were much fewer boats today, with the high winds.

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

Gentle Winds and Plentiful Wildlife

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Weather:

  • Visibility 15+ NM
  • Sky partly cloudy
  • Wind 5-10 knots N
  • Sea state: Calm

Visitors/Boats:

  • Yesterday Laura and Greg came at low tide to deliver fuel and for Laura to teach her online class.
  • Greg came this morning to deliver a load of fresh water which we pumped into our storage tank with the fire pump and hoses.
  • Today we saw a dive vessel in the reserve but no divers. They were fairly close to the wildlife but the sea lions did not seem particularly bothered.
  • One small pleasure craft hovered just outside of the reserve for the majority of the day. They were too far away to see what they were doing, but usually boats like this are fishing.

Ecological:

  • The small seal pup is still here, but she has become more adventurous over the past week. We have seen her napping on the east side of the island, and beside the decommissioned diesel tank on the west side.
  • The sea lion population continues to grow, and so does the smell! We will need to set up more fencing soon before they begin to take over the island completely.
  • The pair of crows that we have been seeing returned today and spent most of their day at Race Rocks.
  • We have continued to observe bald eagles in the reserve. We enjoy watching them swoop overhead and cause a stir amongst the seagulls.
  • One of the seals that we have been joined by over the past weeks was also spotted here in December (juvenile female V173). We are still waiting to hear from the researchers who tagged her to see if there is anything interesting to learn.
  • The elephant seals activity has been uneventful as they continue to moult. They spend their days napping and lounging on our “lawn” or wiggling down to the jetty to soak in the shallow water (and perhaps relieve the itchiness of all that peeling fur!).
  • At low tide yesterday we spotted many neat creatures in the exposed pool on the east side of Great Race Rock: urchins, anemones, crabs, fishes, chitons, barnacles, and tubeworms!

 

April 13 and 14 – End of Shift

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Wind: yesterday variable 2-28 knots, today W 7-38 knots
Sea State: yesterday calm, today rippled in morning and up to 1 m chop in evening
Visibility: both days 15 NM
Sky: both days clear
Temperature: yesterday 7-13 °C, today 8-11 °C
Atmospheric CO2: 415.81 ppm (recorded by NOAA at Mauna Loa Observatory, Hawaii)

Today is my last full day on the island before the shift changeover. Tomorrow morning, Mara and Kai will arrive to take over as Ecoguardians. They were here last year from May to September.

I spent the past two days finishing up some tasks around the island and cleaning. I also took time to walk around the island and get a look at all of the incredible species, land and shoreline that make up this ecological reserve.

There were no boats in the ecological reserve.

See the photos below for some views from around the island.

  • The combination of clear water and low tide make it easy to see lots of colourful seaweeds, surfgrass, urchins and other intertidal species.
  • Two swallows were fluttering around the island yesterday. This one landed on the a cable on the winch long enough for me to take a photo.
  • At first I thought it was barn swallows, but then with the help of a field guide realized it’s a violet-green swallow.
  • The sun peering over the horizon at 6:20 this morning.
  • The lighthouse just after sunrise this morning. The moon, in its third quarter, can be seen to the south.
  • A thayer’s gull with a Canada goose egg in its beak.
  • Can you spot the juvenile elephant seal in the middle of the photo, amongst the group of california sea lions?
  • A beautiful sunset on the edge, where the land meets the sea meets the sky.

The Flag is Back

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Weather: 

  • Sky overcast, some clear patches (not much solar power generated today)
  • Visibility 15+ miles, no fog
  • Wind 10-20 knots W
  • Water calm. Some interesting standing wave patterns lately.

Boats/Visitors: 

  • On Thursday Greg came in the afternoon to top up our water supply. Pearson alum Norbert (currently alum in residence) also came along for the ride to check out our solar panels and provide suggestions for future improvements. Pearson maintenance volunteer Jimmy also stopped in for the night to visit race rocks before he goes home to Mexico. Safe travels!
  • We had many hands on deck, so we were able to successfully repair and raise the flagpole.
  • Yesterday Greg visited with a group of college guests who toured the island.

Ecological: 

  • The sea lions have started to haul out on the N + S/SW sides of Great Race Rock.
  • The oyster catcher chicks have grown to be nearly as big as their parents and are flying all over!
  • The seagull chicks are getting bigger and when rival adults attack they now fight back. On Thursday we spotted a chick with one eye pecked out and were concerned that it would not survive. Fortunately, when we checked later it was doing well.
  • There have been large numbers of black turnstones present this past week, 30+ at once

 

 

 

March 2 – Shift Change

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Sunny
Wind 5-10 knots S to SW
Low 5oC
High 9oC

Two whale watching boats were seen in the ecological reserve.

Today was the shift change that saw Alex depart after being on for three months and Virginie for a month. It was a calm and glorious day to ferry the supplies and people back and forth to Race Rocks. Thank you Alex for all the great work you have done and the great shape you have left the place. I will be here until the end of March.

Strongylocentrotus droebachiensis: Green sea urchin –The Race Rocks taxonomy

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See this green urchin in the video and compare it with the purple and red urchins

 

Green Sea Urchin: average size is 50-60 mm, but may reach a maximum size of about 85 mm.

Distribution: The green sea urchin is one of the most widely distributed of all Echinoderms. It has a circumpolar distribution, which extends into the Arctic regions of both the Atlantic and Pacific Oceans. It commonly inhabits the rocky subtidal zone from the low-tide mark down to a depth of 1200 m, but also occurs intertidally in tide pools.

 

 

Diet: The green sea urchin primarily grazes on seaweeds (kelp being its preferred food source), but will also consume a wide variety of organisms including mussels, sand dollars, barnacles, whelks, periwinkles, sponges, bryozoans, dead fish, and – when hungry enough – other sea urchins.

This shows the grazing action of sea urchin teeth, arranged in a complex assemblage of small bones, the five teeth gouged out this star pattern in the stipe of a Pterygophora.

 

The skeleton of the sea urchin is called a “.test”. The radial symmetry is reflected in the placement of all the tube feet holes. Here you can see the size of a green urchin compared to a red urchin

 

 

 

Reproduction: Green sea urchins release their gametes into the water column where the eggs are fertilized by the sperm. The sexes are separate. The resulting larva (termed an “echinopluteus”) undergoes development planktonically for a period of one to several months before settling on the sea floor and metamorphosing into the adult form. Reproduction occurs on an annual cycle with spawning occurring in the spring, generally between February and May, but sometimes as late as June.  See the Lab on Sea urchin Embryology.

This video from underwater Safari shows a wolf eel crunching a sea urchin…

Behavior: Where urchins occur at high density, destructive grazing can produce habitats devoid of seaweeds. These areas may be termed “sea urchin barren grounds”.. When sea urchins are removed from these sites, either manually or by disease, the reduction in grazing pressure often results in the development of highly productive kelp forests. These kelp beds provide shelter for a wide variety of marine organisms (e.g. fish, lobsters, crabs, sea stars, bivalves, gastropods, bryozoans) and the habitat is typically much more diverse than barren grounds. Hence, sea urchins are one of the principal factors controlling habitat diversity in the rocky subtidal environment.

Other Members of the Phylum Echinodermata 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.

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