Tag Archives: predation

Sealions and salmon

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Good Evening
TEMPERATURE: Max. 12.1 ºC »» Min. 9.9 ºC »» Reset 11.5 º C »» Rain 14.9 mm
MARINE LIFE: There is still good fishing for the birds and sea lions,in the span of about 1 hour saw 8 good sized fish taken by 5 California and 3 Northern Sea lions just off the end of the dock. The Northern Sea lions seem to spend more time in the water, maybe with their greater size they feed more often. The California S.L. sleep a lot during the day but judging by the noise during the night they are quite active coming and going.This afternoon one Blue Heron sat out on the kelp for almost 2 hours then headed back towards Pedder Bay. Nice to get the rain, the birds like it even if the puddles are small.
HUMAN INTERACTION: Second Nature out with some supplies, the station boat to Pedder Bay and back with a short stop at the campus.
posted by Carol or Mike S at 6:05 PM

 

Good Morning
WEATHER: Sky Overcast »» Vis. 3/4 Mile Lt. Rain and Fog »» Wind North 10 Knots »» Sea Rippled
posted by Carol or Mike S at 7:01 AM

Salmon predation

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TEMPERATURE: Max. 18.3 ºC »» Min. 9.9 ºC »» Reset 15.1 ºC
MARINE LIFE: The fishing is good these past few days at least for the birds and sea lions, have seen some fair size salmon taken just off the end of the dock -a couple looked to be about 3kgs. The birds, especially the gulls rush to pick up any bits of fish that fly about as the sea lions toss and slap their catch at the water surface. There are also a lot of smaller fish which we see jumping, some clearing the surface by a foot or more.

HUMAN INTERACTION: Second Nature out with Garry and students(divers) for live web cast, also Hyaku with Angus and two guests from the Jason Project.The weather could not have been better, over a week now of clear skies and calm seas! There were 5 pleasure craft and 11 Ecotour boats through the reserve, unfortunately at approx. 15:00 one boat from Sea Fun Safaris approached the south shore of North Rks. too close and about half of the 50 or so cormorants took flight.Several sea lions sat up but fortunately did not rush into the water. The sea lions near the dock are quite used to us moving about as long as we move slowly, and don’t make a lot of noise or try to get too close.
posted by Carol or Mike S at 6:05 PM

Kayakers approach so quietly they can startle the wildlife-

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Thursday, July 18, 2002
Good Evening
TEMPERATURE: Max. 16.1 C  10.7 C  Reset 14.3 C
posted by Carol or Mike S at 6:15 PM
Good Morning
WEATHER: Sky Overcast  Vis. 15 Miles Wind South West 10 Knots  Sea Rippled
posted by Carol or Mike S at 5:03 AM
Wednesday, July 17, 2002
Good Evening
TEMPERATURE: Max. 16.0 C  Min. 11.0 C Reset 12.1 C  Rain tr
MARINE LIFE: Was nice for a change not to have the wind today,don’t mind the clouds, certainly good weather for the chicks- not too hot.The food supply seems to be holding out see lots of nice fresh fish being brought back by the gulls and everywhere you look Pigeon Guillemots returning with blennies. Some of the gulls are going quite a distance at times judging by the clam shells rolling off the roof ! They drop the clams onto roof and the sidewalks to break them open,quite noisey and very messy.
HUMAN INTERACTION: The Hyaku was in this morning,Ryan brought some mail and supplies from the college Ryan brought a group through the reserve in 2nd Nature in the afternoon but did not come ashore. This morning there were a couple of kayakers through and unfortunately they ignored the guidelines with respect to staying the proper distance from shore. This time of the year it is particularly important to follow the guidelines so as not to interfere with feeding birds and harbour seals with pups and those about to give birth.The noise from power boats at least give fair warning but kayakers approach so quietly they can startle the wildlife-please remember maintain at least 100 metres from any marine animal or bird and back off at the first sign of disturbance or agitation.
posted by Carol or Mike S at 6:35 PM
Good Mornng
WEATHER: Sky Cloudy  Vis 15 Miles  Wind West South West 15 Knots Sea 1 Foot Chop
posted by Carol or Mike S at 5:01 AM

The eagle was trapped head first in a crevice , unable to take flight.

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Tuesday, July 16, 2002

Good Evening
TEMPERATURE: Max. 15.9 �C �� Min. 10.0 �C �� Reset 13.7 �C
posted by Carol or Mike S at 6:18 PM
Good Morning
WEATHER: Sky Overcast Vis. 15 Miles  Wind West 23 Knots  Sea 2 – 3 Foot Chop
posted by Carol or Mike S at 5:05 AM

Monday, 2July 15,2002 Good Evening

TEMPERATURE: Max. 15.0 C  Min. 9.9 C  Reset 13.1 C
MARINE LIFE: Still the main activity centres around adult birds feeding chicks. The gulls announce their arrival and the chicks run from their hideing spots. Getting the food entails somewhat of a ritual, the adult nods it’s head a few times,then pecks at the ground a few times while the chicks gather around and finally the food is regurgitated but the chicks have to be fast because as they are attempting to pick at the food with their bills the adult is also snatching up the goodies.The first time I watched this feeding process I thought the adult was just plain mean to dump the food ,then gobble it up again as the chicks are trying to eat but I see the purpose of the exercise is to teach the chicks to be quick. It would seem the chicks that learn the fastest, grow the fastest! Survival of the fittest.There were three harbour seal pups born on the rocks along the north shore of Gr.Race today.At about 17:00 there was a lot of gull squawking and most of them were diving at an eagle sitting just at the waters edge on the northeast tip of Gr. Race. The gulls kept up a constant barrage on the eagle which ducked and put up it’s wings for protection. The eagle was trapped head first in a crevice , unable to take flight. The assault from above by the gulls continued for about 10 minutes before the eagle managed to manoeuver around enough to take off but even then with the gulls diving at it’s head it could not really fly and was forced down again but this time out of our sight. All but 3 or 4 gulls settled back down but not seeing the eagle fly away I was curious to see what happened so carefully -with sou’wester firmly in place, and not to keep the rain off- I moved slowly along the rocks to have look. The eagle was busy eating the placenta left from one of the seal births earlier in the day.I backed off quickly and left the poor bird to eat in peace which it did and then flew off towards Bentinck Island about 20 minutes later.
HUMAN INTERACTION: There were 3 pleasure craft in the reserve today.
posted by Carol or Mike S at 6:09 PM
Good Morning
WEATHER: Sky Cloudy  Vis 10 Miles  Wind West 19 Knots  Sea 2 – 3 Foot Chop
posted by Carol or Mike S at 5:59 AM

A Turkey Vulture was flying about in the strong winds,

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Thursday, June 06, 2002
TEMPERATURE: Max. 12.0 C  Min. 11.0 C  Reset 11.0
MARINE LIFE: Early this morning one Bald Eagle flew around the Gulls nests, spending around 10 minutes looking for prey, despite the constant harassment by the Gulls. The eagle flew of to the west, and was out of site. Perhaps an hour later two Bald Eagles were spotted hunting together, they brought down a Glaucous-winged Gull and one eagle was seen carrying a Gull wing away. There was also other interesting bird action mid-morning. A Turkey Vulture was flying about in the strong winds, attempting to find food. The winds were a challenge for the vulture, with the bird struggling in the gusts. It was particularly noteworthy that the Black Oyster Catchers made a great effort to harass the vulture. This was caught on video just before the divers entered the water and can be seen at http://www.racerocks.com/racerock/archives/vidbenmovie.htm The divers reported an abundance of sperm and eggs in the nutrient rich water off the docks.
HUMAN IMPACT: No whale watching activity within the reserve today. Indeed the strongs winds, 25-35 knots, kept most vessels away. Hyaku docked twice, bringing equipment and materials for the web-cast and conduit repairs. One major disturbance was the Defence Forces Blasting on Bentinck Island which clearly frightened the Sea lions into the water, Around 10 of the 12 Sea lions disappeared within the first two blasts, approximately 10:30am, and have not yet returned. (Note: As of June 18- they have not returned- will not be back until August now. ) .The three blasts with only a few minutes spacing sent shock waves that rattled the house and were not at all pleasant.
posted by at 9:45 PM
Good MorningWEATHER: Sky Partly Cloudy  Vis. 12miles  Wind West 25-30knots Sea 2-3 foot chop and rising posted by at 6:42 AM

A large pod of Orcas passed straight through the reserve

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Monday, June 03, 2002
Good Evening
TEMPERATURE: Max. 12.0 C Min. 8.8 C Reset 11.0
MARINE LIFE: Some fabulous marine events today, despite an early fog that reduced visibility to less than a quarter of a mile. A large pod of Orcas passed straight through the reserve late this afternoon, perhaps 6 in total. The whales seemed to be on the hunt however no Seals or Sea lions were taken. A Bald Eagle was also seen flying across west Race this afternoon, taking either a Oystercatcher, Crow or Pigeon Guillemot with it.
HUMAN IMPACT: A total of twelve eco-tourism boats were about the reserve today, most adhering to the reserve guidleines. However, one boat in particular was wthin the reserve directly following the Orcas. Despite an agreement to stay out of the reserve when whales are present in order to allow the whales some space. Hyaku and Zodiac also docked bringing equipment and supplies.
posted by at 10:22 PM
Good Morning
WEATHER: Sky Cloudy  Vis 8 Miles  Wind West 15 Knots  Sea 1 Foot Chop
posted by at 7:25 AM

–with the tail of the fish in it’s talons and the fish head bouncing off the water surface

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Tuesday, April 30, 2002
Good Evening
TEMPERATURE: Max. 16.5 ºC »» Min. 5.7 ºC »» Reset 10.3 ºC »» Hi – Low and Totals For April »» Hi 16.5 ºC day 30 »» Low 3.1 ºC day 08 »» Total Rain 61.7 mm »» No snow
MARINE LIFE: 3 bald eagles( 1 juvenile ) With the very low tide this morning it was a seafood buffet for the birds and otters.Watched two determined gulls try to drag a large fish carcass that looked like a ling cod, out of water on to the rocks.They worked at this for over 20 minutes to no avail. Suddenly out of the fog the young eagle landed 2-3 metres away from the gulls which moved out of the way. The big bird had little trouble getting the fish carcass up on the rocks where it had a better hold then spent about 15 minutes feeding, all the while the gulls were getting more brazen, moving closer to maybe take back the fish.Not about to share, the eagle took off towards the southeast rocks with the tail of the fish in it’s talons and the fish head bouncing off the water surface several times before it was completely airborne. When the eagle had it’s fill the gulls and crows moved in to scrounge what they could.
HUMAN INTERACTION: 2 Ecotour boats and 3 Pleasure craft through the reserve today.
posted by Carol or Mike S at 6:18 PM
Good Morning
WEATHER: Sky Partly Obscured »» Vis. 2 – 4 Miles Fog »» Wind West 11 Knots »» Sea Rippled
posted by Carol or Mike S at 6:25 AM

(eagle) eating the catch of the day (salmon).

Posted on by
Saturday, April 20, 2002
Good evening from Chris and Jane.
We arrived this morning at 11:45 am and took over for Mike and Carol today. As we approached Race Rocks, we both commented on the flag being at half mast. Even on this small island, as on parliament hill and across the country, the symbol of loss was displayed for the four soldiers and their families. Our thoughts were with them.WEATHER: Winds were at 10-15 knots, seas were rippled. Visibility was 10 miles. Clear skies.

MARINE LIFE: 3 bald eagles, two jeuveniles were seen on the south tip of Great Race. One adult on the cliff by the helipad. An adult was seen later in the day at the southern tip of great race, eating the catch of the day (salmon). Three Canada Geese were seen… two were a pair and located on the north eastern area of the island. The other was near the lighthouse. Some of the seagulls are starting to practice and display nesting behaviours. It looks like pairs are starting to form and courtship rituals are taking place. Two pairs of oyster catchers were seen. One on the north eastern side of the island and the other on the docks.

HUMAN INTERACTION: Six boats were fishing off of Rosedale Reef this morning. These were later seen further to the west of Rosedale Reef in the afternoon. They were checked on by a vessel from Fisheries and Oceans early in the afternoon. In the midafternoon, we observed one disabled vessel being towed back to Pedder Bay. One ecotour boat visited the area today and a few fishing vessels stopped on their way in and out to have a visit with the sea lions.

We are going to be returning back to Pearson College Campus at 20:00 hr after another great day on the rock!
Until next time,
Chris and Jane
posted by Chris Blondeau at 6:55 PM

Good Morning
WEATHER: Sky Cloudy »» Vis. 15 Miles »» Wind 13 South West »» Sea 1 – 2 Foot Chop
posted by Carol or Mike S at 6:39 AM

Psolus chitonoides: creeping pedal sea cucumber

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Predation of a Psolus chitinoides by a sea star is examined and discussed by Laura and Nadege. The stomach of the sea star surrounds the sea cucumber and the soft neck and mouth of Psolus is well inside the cavity of the sea

 

Sea cucumbers have inhabited the world’ s oceans for about 400 million years. Psolus chitonoides is an unusual species of these marine invertebrates. Its diverse characteristics have given it 4 common names: Armoured sea cucumber, Creeping armoured sea cucumber, Slipper sea cucumber and Creeping pedal sea cucumber.

Compare the tentaclesof Psolus with the end of the California Sea Cucumber to the left. Photo by Dr.A.Svoboda

Tentacles of P.chitinoides

A-Description

As all echinoderms, the creeping pedal cucumber has a spiny skin. Also, its appearance is closer to a chiton than to a sea cucumber (here is the origin of its name “chitonoides“).

1-External features:an oval body (7cm long to 5.8 cm wide) domed dorsally with stiff, shingle-like scales, flat, flexible sole ventrally. Its tentacles(8-10) are dendritic, equal in size, or 8 large and 2 small. Also observing the body, it could be compared to an elongate cylinder lying on its side with the mouth at one end and the anus at the other. The rows of tube feet run the length of the body

2-Internal features: the tentacle ampullae, the rete mirable and cuverian organs are absent . On the other hand, we can observe the presence of retractor muscles. Respiratory trees are “y shaped”. Note that its madreporic body is attached to a dorsal mesentery. Its internal calcareous skeleton is composed as following:calcareous ring with anterior processes only. Psolus chitonoides is characterized by typical skin ossicles, where one type of circular perforated plate (some with knobs coalesced into a raised network) occur only in the ventral sole.

Domain Eukarya
Kingdom Animalia
Phylum Echinodermata
Class Holothuroidea
SubclassAspidochirotacea
Order Dendrochirotida
Family Psolidae
Genus Psolus
Species chitonoides
Common Name: Creeping pedal sea cucumber
B-Physiology and Biology

1-Suspension feeder: tentacles trap larger particles (larger than 2mm) by bending inwards to form a cagelike enclosure. The mouth lips extend toward the particle as the nearest tentacle pushes it into the mouth .

2-Reproduction : the reproductive organs of a sea cucumber generally consist of 1 or 2 tufts of elongated tubules in the forepart of the body cavity.Spawning occurs annually, from mid March ot late May, commonly in the early morning. A spawning male will swab its genital papilla with its tentacles, then lift the tentacles to disperse the sperm . Females release long ropes of brick red eggs; fertilized eggs develop into pelagic lecithotrophic vitellaria larvae. Late larvae and early juveniles are negatively phototatic and settle gregariously.

3- Respiratory system: its water vascular system is a hydraulic system made up of tubes and valves that operate rows of extendible tube feet . As other sea cucumbers, Slipper sea cucumbers respire through their tube feet, body wall and respiratory trees.

4-Chemicals: there are toxic chemicals (saponins) on its tentacles, discouraging predators from nipping the tentacles. For example, even the Kelp Greenling (Hexagrammos decagrammus), which feeds on sea cucumbers, avoids this species.

C-Predators, parasites and commensals

1-Sea stars and fish are the main predators of the Psolus chitonoides.

2-Parasitic forms of flatworms and snails can live inside the sea cucumber

3-Commensal organisms are mostly scales that mimic the colour of sea cucumbers, and crawl on their skin.

D-Habitat

From exposed coast to sheltered inlets; although it seems to prefer clean, vertical rock that is free of sediment. Its soft, flat sole enables it to attach firmly to rock.

E-Range

Aleutian Islands to Baja California ; intertidal to 247m ; common in shallow subtidal areas.

References:

Kozloff, E.N. Keys to the Marine Invertebrates of Puget Sound , the San Juan Archipelago, and Adjacent Regions.

Lambert, P. 1997. Sea cucumbers of British Columbia, Southeast Alaska, and Puget Sound. UBC Press,

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.

 March October 2003-  Rahilla (PC)

Herring ball feeding

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Friday, February 01, 2002
Good Evening
TEMPERATURE: Max. 7.1C Min 4.3C Reset 5.1C Rain 0.6 mm
MARINE LIFE: 15 mature and 3 immature Bald Eagles today. They were feeding with several hundred gulls, cormorants, common murres and scoters in small but frequent fish balls, mostly outside the reserve.
HUMAN INTERACTION:2nd Nature in with Garry and guests and also Angus with guests and the mail!
posted by Carol or Mike S at 9:03 PM
Good Morning
WEATHER: Sky Cloudy  Vis. 15 Miles  Wind South 9 Knots  Sea Rippled
posted by Carol or Mike S at 7:18 AM