Health Assessments of Common Bottlenose Dolphins (Tursiops truncatus): Past, Present, and Potential Conservation Applications

Abstract

The common bottlenose dolphin (Tursiops truncatus) is a global marine mammal species for which some populations, due to their coastal accessibility, have been monitored diligently by scientists for decades. Health assessment examinations have developed a comprehensive knowledge base of dolphin biology, population structure, and environmental or anthropogenic stressors affecting their dynamics. Bottlenose dolphin health assessments initially started as stock assessments prior to acquisition. Over the last four decades, health assessments have evolved into essential conservation management tools of free-ranging dolphin populations. Baseline data enable comparison of stressors between geographic locations and associated changes in individual and population health status. In addition, long-term monitoring provides opportunities for insights into population shifts over time, with retrospective application of novel diagnostic tests on archived samples. Expanding scientific knowledge enables effective long-term conservation management strategies by facilitating informed decision making and improving social understanding of the anthropogenic effects. The ability to use bottlenose dolphins as a model for studying marine mammal health has been pivotal in our understanding of anthropogenic effects on multiple marine mammal species. Future studies aim to build on current knowledge to influence management decisions and species conservation. This paper reviews the historical approaches to dolphin health assessments, present day achievements, and development of future conservation goals.

Staying Alive: Long-Term Success of Bottlenose Dolphin Interventions in Southwest Florida

“…For example, we work closely with some of the same team members responsible for the successful Florida manatee rescue and rehabilitation program described in Adimey et al (2016). We also have decades of experience safely conducting collaborative capture-release health assessments on resident dolphins in Sarasota Bay (Wells, 2009;Barratclough et al, 2019), so the necessary equipment and expertise are readily available to respond when entanglements are reported. In addition, many of these rescued animals were long-term resident dolphins that spend substantial amounts of time in shallow, inshore waters, which allowed for relatively easy case monitoring, facilitating sometimes multiple remote disentanglement attempts or capture-release rescue operations per individual, which increased our likelihood of success (Wells et al, 1998(Wells et al, , 2008(Wells et al, , 2013.…”

Age determination of common bottlenose dolphins (Tursiops truncatus) using dental radiography pulp:tooth area ratio measurements

“…The dolphin population in SB is well-studied and substantial life history data are available from photo-identification of individuals to confirm chronological age for method validation [ 32 , reviewed in 58 ]. Likewise, ongoing photo-identification efforts in BB since the Deepwater Horizon oil spill have resulted in sufficient information to establish age for many younger animals in that population [ 58 – 60 ].…”

“…The dolphin population in SB is well-studied and substantial life history data are available from photo-identification of individuals to confirm chronological age for method validation [ 32 , reviewed in 58 ]. Likewise, ongoing photo-identification efforts in BB since the Deepwater Horizon oil spill have resulted in sufficient information to establish age for many younger animals in that population [ 58 – 60 ]. In these populations, ages have been verified based on photo-ID data collected shortly after birth (i.e., sighted as a neonate with fetal folds present) and therefore accurate within approximately 6 weeks [ 61 , 62 ].…”

Standardization of Dolphin Cardiac Auscultation and Characterization of Heart Murmurs in Managed and Free-Ranging Bottlenose Dolphins (Tursiops truncatus)

“…20455. All dolphins in this study were given complete veterinary examinations as previously described, and were assigned prognostic scores indicative of their overall health status ( 15 , 51 ). Nineteen dolphins were auscultated in SB, 10 males and 9 females (1 confirmed pregnant on ultrasound), ranging in age from 2 to 47 years, and 168 to 281 cm in total length.…”