DVM, MSc (Exper Surg)
Current research work is focused in the area of ‘One Health’, specifically the role of climate change (including contaminants) on health and growth of marine animals and, by extension, potential impact on human health. One specific topic is ecotoxicology and physiological impacts of heavy metals in fish, elasmobranchs (sharks) and marine mammals. As well, comparative physiology between marine species that are adaptive can help our understanding of human maladaptive pathologies and is also explored. In the cardiovascular system, research has focused on the developmental and maturation aspects of myocardial metabolism and function of the neonatal and pathological myocardium and the role of gender and sex hormones and responses to stressor such as hypoxia and hyperoxia, where once again, knowledge from marine species adapted to limited oxygen supply during diving has relevance.
Keywords: Mercury/ Cadmium/ Arsenic/ Heavy Metals/ Marine animals/ Contaminants Heart/ Development/ Sex Hormones/ Metabolism.
Dr. Wittnich's research programs focus on the ‘One Health’ concept including the role of contaminants in marine animals and potential implications for human health and using marine mammal diving adaptations to address the "high risk" heart patient population, with particular emphasis on newborn children and women.
The program in contaminants in marine animals, has identified longstanding heavy metal levels such as mercury, arsenic and cadmium in various species along eastern Canada’s coastline and explores the trends over time. As well, other critical more global ecological issues such as red tide, oil spill effects and tracking of world-wide stranding data in a comparative fashion has elucidated new awareness of these issues. Specifically our research has identified and published detailed levels of full heavy metals profiles in various species of fish, and identified a number of negative physiologic effects such as reduced weight for length compared to historical data. Additionally, in a unique anadromous species, Alewife, an 85% incidence of spinal curves, not visible externally, was also documented. The causes for this concerning finding is being further investigated, as commercially relevant fish such as herring also exhibited this abnormality. This research has also demonstrated that heavy metal levels in the various species of fish appeared correlated to where in the water column these fish reside. Additionally, research is also monitoring the heavy metal levels in various organs of Elasmobrachs (sharks), considered the top marine predator, annually in the Bay of Fundy/Gulf of Maine area. Concerning levels of select metals, including arsenic and cadmium have been found consistently, and since humans consume these fish, this has significant implications for their health as well. Finally, monitoring of heavy metal levels in marine mammals in this area is also being conducted by analyzing tissues taken from stranded (died and beached) animals, which include numerous seals and whales. The field work is conducted at a research station (Comeauville Marine Institute) run by the Oceanographic Environmental Research Society, in Nova Scotia along the Bay of Fundy shores.
Related to the cardiovascular system, heart research tackled the issue of development and maturation and the role of gender (sex hormones) in the heart's ability to tolerate stress and how this influences heart disease patterns. One specific area relates to low oxygen (cyanosis), common in newborn children with heart abnormalities, in which research has identified a threshold level of oxygen deprivation, below which rapid metabolic stress is seen, including reductions in energy levels in the heart. These reductions are of concern since earlier work identified reduced ATP levels rendered a young heart at significantly greater risk of earlier damage, despite the use of techniques such as hypothermia to reduce metabolic stress. Interestingly marine animals have adaptations which, in some cases, mimic those of some human pathologies and thus exploring why they are adaptive can provide insights to advancing innovative treatments for humans with relevant pathologies.
Procedures: HPLC, mass spectrometry, fish morphometrics, necropsy, tissue biopsies, microCT scan.
Analytical balances, benchtop centrifuge, HPLC, low and high-speed centrifuge, low and ultralow freezers, water baths.
Committee member/officer of national or international scientific organizations:
Member of United Nations Atlas of the Oceans
Member of Network of Healthcare Advisors
Member of CVMA Advisory Board, Canadian Veterinary Reserve
Observer Member of CVMA Secretariat
Deputy Chair of Clinician Working Group