At ECoMAR, our research team closely follows these giants of the ocean. With a precise and gentle method, we collect only a very small piece of skin and fat, approximately 2 cm, to discover precious information about their health and life trajectory.
What is a cetacean biopsy?
What is cetacean biopsy? Cetacean biopsy, i.e. whales and dolphins, is a low-invasive technique for collecting a small sample of skin and fat. Generally, researchers use special equipment - for example, a crossbow - which fires a dart with a tip attached. This tip, adapted for whales and dolphins, removes a sample of tissue from the animal as it swims freely in the ocean. The procedure is quick and precise. Comparing the size of a whale with the sample removed, it's like an injection with a fine needle. Scientific studies have shown that most animals don't react to the procedure, while some others react quickly as if they had been frightened. Most importantly, the animal remains free in the water at all times, without the need for nets or restraint.
Why collect tissue from these animals?
Collecting biopsies from whales and dolphins is important because each little piece of tissue carries a wealth of scientific information. Through it, we can learn about:
Health and contamination: The tissue shows whether the animal has accumulated heavy metals, pesticides or other pollutants. For example, scientists detect levels of mercury and PCBs (industrial pollutants) which indicate the degree of pollution in the marine environment.
Genetics and identification: With the sample's DNA, it is possible to find out whether the animal is male or female, its parentage and family lineage. This way, we can find out if two whales seen in different places are related or even mother and calf, helping us to understand how populations are structured.
Diet and food ecology: The skin retains indicators of what the animal has eaten, by analyzing stable isotopes or fatty acids. This allows us to know whether the whale feeds on krill, fish or squid, for example, helping to piece together the ocean's food web.
Hormone dosage: The sample can reveal hormones that indicate whether the female is pregnant or not, as well as the presence of hormones indicative of stress, such as cortisol. This information also helps to understand the health of these individuals.
Each sample acts as an individual health report, which is fundamental to understanding and protecting species. This information is only possible through non-lethal, minimally invasive methods such as biopsies, which safely collect data that was previously inaccessible.
Quick, safe and painless collection
The biopsy is much more delicate than we imagine. Scientific studies show that the animals' reaction is imminently short and mild. In general, upon receiving the dart, the cetacean may give a subtle “jerk” or a brief instantaneous dive, and then resume normal behavior in less than a minute. International research reports that whales often don't even show a reaction. In tests with orcas in Antarctica, 66% of the biopsy attempts didn't even make the animal change its behavior. When there was an impact, it was almost imperceptible - a quick twitch or dive - and no strong or prolonged reaction was ever observed. In other words, there are no open wounds or detectable suffering (Read the work by clicking here)
How this data helps conservation
The information obtained is fundamental to conserving the species. By analyzing the DNA, health and diet of cetaceans, we can map how populations are doing in the environment. For example, knowing that a population of whales has high levels of certain pollutants can lead environmental agencies to investigate sources of contamination in that region. If we discover that a group of dolphins is genetically isolated, we can propose safe marine routes or protected areas to connect populations.
In addition, diet data helps researchers understand which fish sustain marine life and whether human fishing is affecting the natural diet of these animals. Reproduction information (via hormones) indicates whether there are enough pregnant females to maintain the population or whether it is at risk of falling. All of this supports public policies and international marine protection agreements. How this data helps conservation
Ethical and rigorous protocols
It's natural to be concerned about animal welfare. That's why cetacean biopsies are only carried out under very strict ethical standards. All collections are carried out by experienced and trained researchers, following international safety protocols. Before entering the sea, the team has special permits (in Brazil, for example, from IBAMA or ICMBio) that authorize the research under strict conditions.
In the field, clear rules are observed: keep a safe distance from the whales, only shoot when conditions are ideal (animal swimming in parallel and at a safe distance from the boat), and stop the attempt if the group shows signs of stress.
Thus, all aspects of the study - from the approach to the processing of the sample in the laboratory - are carried out under scientific and ethical supervision. The result is a tissue collection that respects the animals: free, brief and painless, for the sake of greater knowledge.
Conclusion
Cetacean biopsy reveals how marine science can be both careful and impressive. With just a small fragment of skin and blubber, we learn about the intimate lives of whales and dolphins - from their menu to their state of health - without harming them. These findings help protect our marine giants and keep the oceans healthier for everyone. Each scientific discovery inspires us to value and conserve these magnificent ocean dwellers, showing that good research is a powerful ally of nature.
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