Empfohlen
Weitere ähnliche Inhalte
Was ist angesagt?
Was ist angesagt? (20)
Ähnlich wie Sea Turtle Injuries on Bald Head Island and their Effects on Fecundity
Ähnlich wie Sea Turtle Injuries on Bald Head Island and their Effects on Fecundity (20)
Mehr von BHIConservancy
Mehr von BHIConservancy (17)
Kürzlich hochgeladen
Kürzlich hochgeladen (20)
Sea Turtle Injuries on Bald Head Island and their Effects on Fecundity
- 1. Sea Turtle Injuries on Bald Head Island and their Effects on Fecundity Joseph A Seebode Bald Head Island Conservancy College of the Holy Cross
- 2. Sea Turtles • Seven Species Worldwide – Found in tropics, subtropics, and temperate oceans of the world • DisFnguishing Features – Hard shell made of bone • Carapace + Plastron – Air Breathing – Lay eggs on land – Cold-‐blooded • Importance of protecFng sea turtles
- 3. Sea Turtles NesFng on BHI • Five species of sea turtles offshore – Only three species known to nest during summer months • Loggerheads typically lay between 100-‐120 eggs in a clutch – Two to three clutches in a nesFng season – Reach maturity around age 25 – Do not nest every year; nest every 2-‐4 years
- 4. IntroducFon-‐ Sea Turtle Injuries • Injuries decrease an animal’s fitness, or ability to survive • Sea turtles someFmes strand on beaches when they are sick or injured • Injuries may kill or seriously affect the health of a sea turtle – University of Florida Study • Hypothesis 1: There has been a change in the number of sea turtles that are injured each year • Hypothesis 2: Sea turtles with injuries will have less ability to acquire food and thus less energy to reproduce and produce eggs
- 5. Methods • Selected years 1993 to 2013 to look at BHI nesFng data; 1998 to 2013 for North Carolina stranding data from seaturtle.org • Recording injury descripFons from sea turtle data binders from the BHIC – Classifying sea turtles as having none, minor, or a major injury • Determining individual sea turtles by matching PIT and Flipper Tags • Comparing the number of eggs laid by sea turtles with no injuries, minor injuries, and major injuries as a measure of fecundity
- 6. Types of Injuries • Causes of sea turtle injuries: boat propeller strikes, entanglement in marine debris, and natural predaFon (such as sharks) • Major-‐ missing a flipper or parFal flipper, large breaks in the carapace, or damage to the skull • Minor – small piece missing from carapace or flipper, small gash
- 7. Results: Injured NesFng Sea Turtles on BHI 0 10 20 30 40 50 60 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 Number of Nes+ng Sea Turtles Year Injured vs. Non-‐injured Nes+ng Sea Turtles on Bald Head Island Non-‐injured Injured
- 8. BHI NesFng Sea Turtles with Major Injuries 0 1 2 3 4 5 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 Number of Sea Turtles w/ Major Injuries Year Number of Nes+ng Sea Turtles with Major Injuries on BHI
- 9. 0 10 20 30 40 50 60 70 80 90 1996 1998 2000 2002 2004 2006 2008 2010 2012 2014 Number of Strandings due Anthropogenic-‐Caused Injuries Year North Carolina Sea Turtle Strandings due to WatercraF Strikes
- 10. Effects on Fecundity • Average Number of Eggs Laid – No Injuries:117.18 • 946 nests – Minor Injuries: 123.23 • 162 nests – Major Injuries : 107.15 • 33 nests • Minor injuries significantly different from no injuries and major injuries; however major injuries not significantly different from no injuries
- 11. Discussion • Number of injuries per year does not change much, but sFll important to find ways to decrease injuries – 400,846 registered boats in NC in 2010 – Jet Propulsion boats found to be safer for sea turtles • # of eggs laid are within or close to the overall average for Loggerhead sea turtles: 100-‐120, even though some significantly differ from one another – Only 33 sea turtles with major injuries found injuries
- 12. Experimental Error • Some nesFng data could not be used: – Sea turtle not observed – Nest lost and egg data not available • Injuries on plastron not able to be observed • Difference in records year to year • RelocaFon egg count and excavaFon egg count may differ
- 13. Injury Recovery & Further Research • Importance of Sea Turtle Hospitals • Natural Healing • Further research required to more fully understand the relaFonship between an injury and fecundity • Study using more sea turtles with major injuries + comparing sea turtle fecundity before and aher an injury occurred • More safety precauFons should be put in place to prevent anthropogenic injuries + sea turtle rescue and rehabilitaFon centers should receive more funding
- 14. Thank you so much! Any QuesFons?