Cycle 2 Sea Turtles

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					The Effect of Species on
Frequency of Surfacing in
 the NY Aquarium’s Sea
    Turtle Population
 A demo UA exit project at the NY Aquarium, conducted by
 Fred Feraco, Rachel Volke, Maria Maldonado, and Lucas
        2. QUESTION
How does species affect frequency
       of surfacing in the NY
  Aquarium’s sea turtle population?
                 3. HYPOTHESIS
The research team in this study predicted that the
   hawksbill turtles would surface to breathe more
   frequently than the loggerhead turtles.
The New York Aquarium has two types of sea turtles: Hawksbill
     (Eretmochelys imbrecata) and loggerhead (Caretta caretta)

According to the Sea Turtle fact sheets at the U.S. Fish and Wildlife service,
     hawksbill turtles generally reach a size between 95 and 165 lbs,
     whereas loggerhead turtles average about 200 lbs at their adult weight.

In fact, the three loggerhead turtles at the NY Aquarium are noticeably larger
      than the single hawksbill. We thought the smaller hawksbill turtle
      might have to work harder to move around the tank, which would seem
      bigger to her. She would therefore need more oxygen, and breathe
      more often.
Sea turtles like the hawksbill and loggerhead are uniquely adapted to their
      maritime environment. describes their breathing style as
      “a single explosive exhalation and rapid inhalation” that lets them
      quickly cycle air through their lungs with a minimum of time actually
      spent at the surface. Turtles’ lungs allow them to continually absorb
      oxygen from the air they have inhaled, even at the higher pressures to
      which they are subjected during their dives.
Thus, we decided to define a “surfacing event” as the breaking of the water’s
      surface by the turtle’s nostrils. Sometimes, a turtle would come close
      to the surface and move its body such that a flipper would break the
      surface, but not its nose. We didn’t count this as a “surfacing event”.
      Other times, the turtles would break the surface with its nostrils,
      submerge its head, and then very shortly afterwards break the surface
      with its nostrils again. We counted these as two separate “surfacing
      events”. Over the long period during which we observed the turtles, it
      became increasingly easy for us to see that characteristic “explosive
      exhalation” when the turtle surfaced, and it was clear that our choice
      in defining “surfacing event” really did seem to reflect discrete breaths
      taken by the turtles.
     4. BACKGROUND INFO. also shares details about how often sea turtles breathe, saying
     that “during routine activity”, surfacing every 4-5 minutes is normal.
     This helped us choose a sampling time of 30 minutes, thinking we would
     get to see 5-7 “surfacing events” for each trial.

  Loggerhead (is that you, Yellow?)         Hawksbill (note darker spots &
                                                  serrated shell)
 Investigation Design Diagram (ID)
     Title: The Effect of Species on Frequency of Surfacing in the NY Aquarium’s
     Sea Turtle Population

     Question: How does species affect frequency of surfacing in the NY
     Aquarium’s sea turtle population?

     Hypothesis: Hawksbill turtles will surface more frequently.
        IV: Species of Turtle
                   Loggerhead Turtles                 Hawksbill Turtles
          2x 30 minute observation periods    2x 30 minute observation periods
     DV: Number of surfacing events (see background research and procedure for

     Constants: Tank/habitat (location), time of day observed (that is, we
     observed both types of turtles at the same time for each trial), individuals
     (same turtles were observed both times), method of measuring surfacing
The four female turtles were identified as follows:

       Turtle                      Identifying marks
       Loggerhead 1                Red tag in back right foot
       Loggerhead 2                Algae-free shell
       Loggerhead 3                No red tag, algae on shell
       Hawksbill 1                 Smallest turtle, more
                                   pointed snout
    Procedures- Overview
 Each of the 4 researchers was assigned a different
  turtle to observe throughout the entire
  investigation. The turtles were distinguished
  based on their unique identification markings listed
  in the preceding table.
 Two data collection trials of 30 minutes each were
  run. Both trials occurred on the same day, one
  from 12pm-12:30pm, and the other from 3pm-
 Data was collected at the Coney Island Aquarium’s
  Sea Turtle Exhibit on November 20, 2010.
         Procedures- Data
 The number of times each turtle surfaced during
  the 30 minute trial was recorded. Surfacing events
  were defined as instances when the turtle’s head
  broke the surface of the water and the turtle took
  a breath.

 The data was collected using an all events focal
  animal ethogram.
  Procedures- Explanation
 The all events focal animal ethogram was selected
  as the most appropriate sampling method because
  we were recording the frequency of the
  occurrence of one event (surfacing) for four
  unique animals. This sampling method made it
  possible for us to focus solely on the occurrence
  of one event for each animal and then compare the
  frequency of that event between the two different
 We watched four female turtles because they were
  the only turtles available. Three of the turtles
  were Loggerhead turtles and one was a Hawksbill
    Loggerhead Turtle Vs Hawksbill Turtle Their Frequencies to
               Surfacing on the Water ( Breathing)
Focal Animal Scan
Sampling Data

  Types of         Trial I    Trial II   Average
Turtle Species       30         30
                  minutes     minutes
                 (Number     (Number
                     of          of
                 surfacing   surfacing             Species of   Average
                  events)     events)
                                                   Turtle       (Breathings)
Loggerhead L2
                 9           5           7         Loggerhead   7.8
 Hawksbill H1
                 2           3           2.5
                                                   Hawksbill    2.5
Loggerhead L3
                 3           11          7         Turtle

Loggerhead L1
                 3           16          9.5
                    Average Number of Breaths
                        Taken by Species
Species of Turtle

                                                Dark Blue –
                                                Light blue -

                            Number of breaths
              8. RESULTS
 Our data shows that the loggerhead turtle on
  average of both trials took five and a half more
  breaths than the hawksbill turtle. The loggerhead
  averaged 7.8 surfacing events and the hawksbill
  turtle averaged 2.5 surfacing events.
              9. CONCLUSION

We thought the hawksbill would surface more often because it's
     smaller. The hawksbill actually ended up breathing far less
     overall in both trials, so you could say our hypothesis was not

There are also reasons to say the data is inconclusive, because
    there were many things we did not take into account. First,
    there were only 3 individual turtles that were loggerhead
    turtles and one individual that was a hawksbill. So the sample
    size was probably not big enough to claim we have a fair
    representation of each species. We also noticed that the turtles
    that breathed more seemed to be more active, swimming all
    around the tank during the 30 minute trial, while the turtles
    taking fewer breaths spent their time in one corner of the
    bottom of the tank not moving. One turtle breathed 3 times in
    the first trial and a whopping 16 in the second, suggesting that
    activity level matters more than species.
  10. (Further Study) NEXT STEPS

One member of our team thought we could try timing the
    actual length in seconds of each surfacing event,
    which might give us a better idea of each individual’s
    lung capacity.

We are also interested to see the relationship between
    activity level and breathing frequency. This could be
    important because it gives us more information about
    how long turtles DO actually stay underwater than
    just their average, calculated surfacing frequency…
    conservation applications?
            11. Literature Cited
“Hawksbill Sea Turtle, Eretmochelys imbricata at". 26
     November 2010 <>. Last updated:
     11/8/2010 5:14:34 PM

“Hawksbill Sea Turtle (Eretmochelys imbricata)”. U.S. Fish & Wildlife Service, North
     Florida Field Office. 26 November 2010.
     turtle.htm>. Last Updated: 1/16/2009

“Loggerhead Sea Turtle (Caretta caretta)”. U.S. Fish & Wildlife Service, North Florida Field
      Office. 26 November 2010.
      turtle.htm>. Last Updated: 11/12/2010

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