Habitat Island, Sunday, June 4^th

Report by Janet Snell and Greg Leach

We had a very successful Oyster event at Habitat Island this past weekend. A big thank-you to all the volunteers who helped with on our third oyster survey of the season. There were eleven people on this sunny day and Joan Lopez dropped by to say hello at the end of the day. (She will be leading Oyster Survey #4 on June 17^th at Cooper’s Park on the North Shore of False Creek)

Our survey took place on Habitat Island at Hinge Park, Olympic Village in False Creek. This more natural environment was created along with the seawall extension in the new Olympic Village neighbourhood in time for the 2010 Olympics. The island features sandy/gravelly beaches strewn with large and small boulders with an accumulation of sediment muck in the lower reaches. 

The crew of iNaturalist volunteers was sufficiently sizeable that we were able to have a very thorough examination of the circumference of the entire island. Not surprisingly, we found that there were considerable differences from one area to another in terms of oyster population density. Before the crew wrapped up for the day, we had a lively discussion about the possible causes of these differences.

As it happened, some of the volunteers were ‘Old Pros’ at iNaturalists while others were ‘rookies’. The Old pros were generous in offering advice and help to the rookies.

We knew that there would be Pacific oysters at Habitat Island but were still surprised and delighted to find so many as the tide reached one of the lowest levels this month. The largest oyster reef was located on the southwest shore in a more sheltered and perhaps warmer bay. This reef was composed of large oysters standing upright at the lower intertidal zone. We had lots of good discussion about why it seemed to be the most populated habitat location.

Higher up on the western side, the intertidal zone is flatter with less boulders and is populated by patches of smaller oysters lying loose on the sandy muck. These oysters looked the closest to the rarer Olympia oysters. However, a closer examination showed the classic ruffled shell of the Pacific oysters. This oyster bed location was also the object of much discussion. Why was this population so much smaller and younger than the oysters at the lowest zone. Had it simply taken longer for the oysters to be distributed higher up on the beach. Were the lower oyster reefs now populating this upper zone? So many questions.

 Another surprise was to see how many oysters were living on the rusty sheet steel piling that was facing the protected bay. This rusty feature is one of the few remains of the industrial past in the nearby area. Perhaps the oysters from this refuge location seeded the newer shores of Habitat Island.

The south-eastern side of the island features another longer and narrower bay which has only a few oysters. This bay has only one inlet/outlet and the water flow is much more restricted. Perhaps there is less food available for the oysters and consequently, less oysters.

Our next survey series is on Sat. June 17^th and Sun. June 18^th at Cooper’s Park on the north shore of False Creek. New volunteers are always welcome, and we look forward to seeing and working with all our volunteers again. 

For information on upcoming events and volunteer opportunities, please contact Volunteer Coordinator, Greg Leach at greg@naturevancouver.ca.

For general project information, contact Project Coordinator, Janet Snell at janet@naturevancouver.ca.