Practical Approaches for Studying Sea Turtle Health and Disease
391
Unfortunately, disease problems in wild sea turtles have been poorly studied.
Those that have been best investigated are diseases that have a dramatic presentation
or have resulted in epizootics (e.g., FP). Those animals that die in small numbers
are probably never seen. Even with stranded turtles that offer a high potential for
examination of ongoing background disease and detection of new problems that are
emerging in a population, little money and resources have been expended on this
valuable source of information.
15.2.4 M ASS M ORBIDITY –M ORTALITY E VENTS VS .
S PORADIC –I NCIDENTAL P ROBLEMS
In a mass morbidity–mortality event, it is easy to appreciate the potential for impact
on a population or species, and investigation of these events takes on high priority.
Investigations, aimed at characterizing the event and identifying causative and contributory factors, may be performed in a more systematic way, involving expert
working groups and coordinated centralized data management, sample routing, and
archiving. Such events, however, may quickly overwhelm the available resources,
and opportunities may be lost because of lack of preparation or timely response.
The magnitude of the event may also stimulate disjointed efforts by several independent groups which can result in poor information-sharing, duplication of efforts,
incomplete workups, and use of different methodologies that make later data comparisons impossible. A mass event provides a series of animals and a range of clinical
presentations and varying severities, which allow a more thorough characterization
of the event and more opportunities to discover all the factors involved. Multiple
opportunities exist to obtain specific samples and to perform diagnostics, although
not always on the same animal.
Sporadic–incidental problems, on the other hand, may seem less important.
However, these cases may provide the first opportunity to document a disease
condition that may later cause a mass morbidity–mortality event. Furthermore,
among free-ranging turtles, what may appear on the surface to be a sporadic,
incidental, or mild condition may in fact be the “tip of the iceberg” — a condition
that is having far more serious impact than appreciated because turtles with severe
disease are lost to predation and only the less affected animals are observed.
Limited accessibility to turtles in certain habitats and especially to early life history
stages exacerbates this problem. Sporadic cases are a challenge because the primary observer may lack the training to recognize them, the understanding and
experience to recognize their potential significance, or the interest to record observations and collect materials. Many of these cases therefore may be worked up in
a very haphazard way, if at all, depending on the interest level and experience of
the observer as well as the availability of funds and resources to conduct these
investigations. These individual cases, however, sometimes provide the best material for thorough workup, especially if the animal can be brought to a clinic with
appropriate facilities and expertise. The value of careful observation and documentation, and a systematic approach, is as great for these infrequent cases as for
mass events.
1123 book.book Page 391 Monday, November 11, 2002 11:11 AM
391
Unfortunately, disease problems in wild sea turtles have been poorly studied.
Those that have been best investigated are diseases that have a dramatic presentation
or have resulted in epizootics (e.g., FP). Those animals that die in small numbers
are probably never seen. Even with stranded turtles that offer a high potential for
examination of ongoing background disease and detection of new problems that are
emerging in a population, little money and resources have been expended on this
valuable source of information.
15.2.4 M ASS M ORBIDITY –M ORTALITY E VENTS VS .
S PORADIC –I NCIDENTAL P ROBLEMS
In a mass morbidity–mortality event, it is easy to appreciate the potential for impact
on a population or species, and investigation of these events takes on high priority.
Investigations, aimed at characterizing the event and identifying causative and contributory factors, may be performed in a more systematic way, involving expert
working groups and coordinated centralized data management, sample routing, and
archiving. Such events, however, may quickly overwhelm the available resources,
and opportunities may be lost because of lack of preparation or timely response.
The magnitude of the event may also stimulate disjointed efforts by several independent groups which can result in poor information-sharing, duplication of efforts,
incomplete workups, and use of different methodologies that make later data comparisons impossible. A mass event provides a series of animals and a range of clinical
presentations and varying severities, which allow a more thorough characterization
of the event and more opportunities to discover all the factors involved. Multiple
opportunities exist to obtain specific samples and to perform diagnostics, although
not always on the same animal.
Sporadic–incidental problems, on the other hand, may seem less important.
However, these cases may provide the first opportunity to document a disease
condition that may later cause a mass morbidity–mortality event. Furthermore,
among free-ranging turtles, what may appear on the surface to be a sporadic,
incidental, or mild condition may in fact be the “tip of the iceberg” — a condition
that is having far more serious impact than appreciated because turtles with severe
disease are lost to predation and only the less affected animals are observed.
Limited accessibility to turtles in certain habitats and especially to early life history
stages exacerbates this problem. Sporadic cases are a challenge because the primary observer may lack the training to recognize them, the understanding and
experience to recognize their potential significance, or the interest to record observations and collect materials. Many of these cases therefore may be worked up in
a very haphazard way, if at all, depending on the interest level and experience of
the observer as well as the availability of funds and resources to conduct these
investigations. These individual cases, however, sometimes provide the best material for thorough workup, especially if the animal can be brought to a clinic with
appropriate facilities and expertise. The value of careful observation and documentation, and a systematic approach, is as great for these infrequent cases as for
mass events.
1123 book.book Page 391 Monday, November 11, 2002 11:11 AM