Eastern Oyster
description
Transcript of Eastern Oyster
![Page 1: Eastern Oyster](https://reader036.fdocuments.us/reader036/viewer/2022062411/5681668c550346895dda509d/html5/thumbnails/1.jpg)
Eastern OysterCrassostrea virginica
![Page 2: Eastern Oyster](https://reader036.fdocuments.us/reader036/viewer/2022062411/5681668c550346895dda509d/html5/thumbnails/2.jpg)
Oyster Life Cycle• Pediveliger• 2 weeks old• Has a foot
• Spat• About 1 year• Spat prefer to settle on oyster shell
• Grow about 1 inch per year
• Females will only release their eggs when there is a reproducing male around and the water temperature is above 72.
![Page 3: Eastern Oyster](https://reader036.fdocuments.us/reader036/viewer/2022062411/5681668c550346895dda509d/html5/thumbnails/3.jpg)
Oyster HistoryOyster populations are at less than 2% of their historical levels.
![Page 4: Eastern Oyster](https://reader036.fdocuments.us/reader036/viewer/2022062411/5681668c550346895dda509d/html5/thumbnails/4.jpg)
Oyster History• Captain John Smith wrote about oyster reefs were so large and
plentiful that they were navigational hazards.
• Captain Smith also talked about oysters being as large as dinner plates.
![Page 5: Eastern Oyster](https://reader036.fdocuments.us/reader036/viewer/2022062411/5681668c550346895dda509d/html5/thumbnails/5.jpg)
What happened to all of the oysters?• Overharvesting• Disease• Poor water quality
![Page 6: Eastern Oyster](https://reader036.fdocuments.us/reader036/viewer/2022062411/5681668c550346895dda509d/html5/thumbnails/6.jpg)
Overharvesting• Before 1910, oysters were harvested with oyster tongs. Using
oyster tongs was not very harmful to oyster populations because it was very labor intensive. Plus, the tongs could only go but so deep.
![Page 7: Eastern Oyster](https://reader036.fdocuments.us/reader036/viewer/2022062411/5681668c550346895dda509d/html5/thumbnails/7.jpg)
Overharvesting• After 1910, the oyster dredge was introduced and the decline
of the oyster was accelerated. Watermen could catch a lot more oysters and destroyed the oyster reefs in the process.
![Page 8: Eastern Oyster](https://reader036.fdocuments.us/reader036/viewer/2022062411/5681668c550346895dda509d/html5/thumbnails/8.jpg)
Overharvesting• Shell was used for
roads, chicken feed or soil additive• Shell was not put
back on the reefs
![Page 9: Eastern Oyster](https://reader036.fdocuments.us/reader036/viewer/2022062411/5681668c550346895dda509d/html5/thumbnails/9.jpg)
Disease• Dermo and MSX took a toll on an already weakened oyster
population.
![Page 10: Eastern Oyster](https://reader036.fdocuments.us/reader036/viewer/2022062411/5681668c550346895dda509d/html5/thumbnails/10.jpg)
Poor water quality• Poor water clarity means no algae which means no food.• Lots of pollution means that the oysters are eating the
pollutants.
![Page 11: Eastern Oyster](https://reader036.fdocuments.us/reader036/viewer/2022062411/5681668c550346895dda509d/html5/thumbnails/11.jpg)
Why are oysters important?• Oysters are important because they can help reduce the levels
of the four major pollutants: nutrient, sediment, toxic and bacterial. They do this as they filter out their food.
• Oyster reefs provide habitat for many other organisms. Without oyster reefs, many animals would not live in an area. This makes oysters a keystone species.
![Page 12: Eastern Oyster](https://reader036.fdocuments.us/reader036/viewer/2022062411/5681668c550346895dda509d/html5/thumbnails/12.jpg)
Why we need to restore oyster reefs?