Thank you, Mr. Chair.
My name is Andrew Trites. I am a professor at the Institute for the Oceans and Fisheries at the University of British Columbia and the director of the marine mammal research unit. I have been studying increasing and decreasing populations of marine mammals for over 40 years and have specialized in studying seals, sea lions and fur seals.
My research encompasses field studies, laboratory work and computer-based studies, many of which were done in collaboration with research scientists in universities and governments in Canada and the United States. I have also served, and continue to serve, on a number of advisory committees, including the marine mammals specialist group for COSEWIC, the Committee on the Status of Endangered Wildlife in Canada. As such, I am acutely aware of the threats and conservation challenges facing pinnipeds in Canada, as well as the challenges pinnipeds pose to fisheries.
Regarding pinniped management and ecosystem impacts, I would like to bring three points of discussion to your attention.
The first concerns the commonly held belief that pinnipeds are out of control, that their numbers are exploding and that there is an overpopulation. Your committee was asked, for example, to “examine the ecosystem impacts of pinniped overpopulation”, rather than simply “examine the ecosystem impacts of pinnipeds”, full stop. To the best of my knowledge, all such statements on overpopulation appear to be based on a baseline of unnaturally low historic population sizes in the 1960s and 1970s, when it was unusual, at least in British Columbia, to ever see a pinniped, because they had been culled and hunted to unprecedented low numbers. In British Columbia, for example, all pinniped populations have recovered or are in the process of recovering from over-exploitation.
There is no overpopulation of pinnipeds. Harbour seals have been stable and at carrying capacity for over 25 years, with about 100,000 animals. The next stable population is for adult male California sea lions, which have numbered about 14,000 since the late 2010s and which originate from breeding colonies in California that stabilized 10 years earlier. Next in line in the stabilization process are the Steller sea lions, which are listed as “of special concern” in Canada and appear to be quickly approaching their carrying capacity of about 45,000 animals.
Adding these three numbers up yields a total of 159,000 pinnipeds, which is a far cry from the 2.5 million people who live in the greater Vancouver regional district. The bottom line is that there is no overpopulation of pinnipeds in B.C. Pinniped populations are balanced and being maintained at natural levels through natural ecosystem processes that do not cost a penny of taxpayers' money.
The second point I would like to briefly reflect on with you is the perception that predation by pinnipeds is bad and harmful to species and ecosystems. This biased view probably reflects the beliefs of many that seals are like humans in their desire to only eat perfect-looking foods, when, in reality, predators such as seals have much better chances of catching slow, diseased and inferior fish, which ultimately makes fish populations healthier.
Similarly, predation by seals also brings indirect benefits to ecosystems. For example, seals that consume predatory fish, such as large hake that eat young herring, can increase the abundance of juvenile herring available for salmon to eat. Finally, there is increasing evidence coming from terrestrial ecology that reintroducing top predators to their former habitats benefits ecosystem stability, productivity and biodiversity. This rewilding phenomenon appears to be naturally occurring in Canada’s marine ecosystems. Our oceans are being rewilded by seals, sea lions, whales and sharks. Thus, the benefits of pinnipeds to ecosystem health appear to outweigh their perceived harm.
The final discussion point I would like to make concerns the confidence different people have in stating the predictions made by mathematical predator-prey models, such as a model that predicts removing half of all pinnipeds in British Columbia will restore west coast salmon. What you may not know is that the chance of the model being right is only 30% to 40%, and it would likely take about 10 to 20 years to determine whether things would actually go according to plan. To some people, 30% to 40% odds are great, because of the amount of money that stands to be made if people can catch more salmon. However, those who put greater value on the life of a seal want more than 80% assurance of models being right before endorsing such predictions. It is therefore important to know, and to ask about, the level of confidence that underlies model predictions.
It is also important to recognize that societal views and values have changed significantly since the 1970s, when pinniped numbers were at their lowest in recorded history.
In conclusion, I don't know of a single case where culling of pinnipeds has had the intended effect.
I would therefore like to encourage you to consider first whether a population of pinnipeds that is stable and at carrying capacity can be deemed to be an overpopulation, and second, whether the benefits that pinnipeds bring to marine ecosystems far outweighs the harm that they are perceived to do. Third, consider whether the low probability that culling pinnipeds would increase the abundance of commercial and sport fish is worth the risk of failure and causing greater harm to ecosystem health and the well-being of other highly valued species such as killer whales and sharks.
Thank you for giving me this opportunity to speak with you today.