Mighty fish migrations are among the greatest marvels of nature. On April 21, 2018, people around the globe will celebrate World Fish Migration Day, building awareness of just how critical moving between habitats is for many species. Why spend the energy to migrate? These fish are on a quest to find suitable sites to spawn and then move back to productive habitats to feed for the rest of the year.
Migratory fishes come in all sorts of sizes, from wee minnows to giant catfish that weigh three times as much as a refrigerator! Regardless of size, many challenges arise during these marathon swims. For example, man-made barriers such as dams can stop fish in their tracks. Rivers around the world now have at least some dams, but few of them include passages to allow fish to migrate around or over them. Not even the Olympic athletes of the fish world, salmon, can overcome such obstacles.
While dams are numerous, their numbers pale in comparison to road crossings. Culvert pipes are installed where our roads pass over streams and rivers. If poorly designed or maintained, these road crossings create major challenges for navigation. In the Laurentian Great Lakes region alone, there are over 257, 000 obstacles (culverts and dams) that fish encounter in their migratory quests. When fish can’t reach ideal locations for spawning or feeding, the consequences for their population size can quickly become noticeable.
World Fish Migration Day is an opportunity to raise awareness about the threats that migratory fishes face, but I think about these challenges year-round. As a research biologist at Shedd Aquarium, I’m currently working with Dr. Pete McIntyre and other scientists from the University of Wisconsin-Madison’s Center for Limnology to discover the effects of culverts on the greatest of the spring migrations from the Great Lakes: white suckers (Catostomus commersonii) and longnose suckers (Catostomus catostomus)! Along with understanding which barriers block fish, I’m also concerned with how the timing of migrations is shifting as our climate warms. Why would it matter if the suckers show up in the streams earlier than usual? Because they fertilize the streams, boosting the growth of plants in much the same way that a gardener does by adding fertilizer to young plants. These nutrients kick-start the food web each year, boosting the growth of the bugs that become prey for stream fish, birds and bats. If the suckers show up before the algae and invertebrates are ready for their growth spurt, the productivity of the whole ecosystem could be affected.
With the help of citizen scientists who volunteer their time to record the arrival of the fish in Illinois, Wisconsin and Michigan, we are creating a first-description of the timing of the enormous sucker migrations from Lake Michigan and Lake Superior. Last year alone, our team documented the migrations of more than 26,000 fish.
We are not alone; many other scientists worldwide are investigating other aspects of fish migrations and how to help reduce the obstacles that block these spectacular animals from fulfilling their quest. Through public assistance and collaborative efforts, we can all help migratory fish get where they need to go.
“Like water, we are truest to our nature in repose”, Cyril Connolly, 1944
Angelo and Elmer sat quietly in their new home, admiring the expansive forest views and the quiet chirping of a nearby flock of finches. Though they’d only arrived a few days ago, the inevitable stress of a cross-country trip and the inherent difficulty of transitioning to a new home and new neighbors was fading. The sun warmed their faces and they leaned back into their respective hammocks with nary a care. Retirement was suiting them.
The two old friends are among a group of seven individuals that now can call the small town of Keithville, Louisiana their new home. They arrived here last month as part of a much larger migration from Alamogordo, New Mexico – a town best known for the nearby Holloman Air Force Base and the site of the historic first explosion of an atomic bomb in 1945. This migration is itself somewhat historic, at least in terms of the history of chimpanzees in this country. Yes, chimpanzees. Angelo, Elmer and their recently translocated friends are chimpanzees among hundreds that have been moved to Chimp Haven, the National Chimpanzee Sanctuary, as part of a mass exodus from their former laboratory homes.
Today, Chimp Haven is home to more than 230 chimpanzees – virtually all of them retired from research centers. The growth of the sanctuary population has been steep, with over 500 chimpanzees moving to sanctuary settings since 2001. While some of these chimpanzees have come from lives as pets and performers, the vast majority are former research subjects and as 2017 drew to a close, it marked the first time in history that more chimpanzees live in sanctuary settings than in laboratories in this country.
At the height of the HIV epidemic in the 1980s, there were likely more than 1,100 chimpanzees living in laboratory settings, many of whom were being considered for testing to combat AIDS. At that time, only a small number of chimpanzees lived in what could be considered a sanctuary, in part because the need for those types of facilities was not clear. But these two population tracks have been on an inevitable trajectory to cross since the 2013 National Institutes of Health (NIH) decision to cease invasive biomedical testing and the associated legislation that deemed that these chimpanzees need be retired from their service as subjects of biomedical research.
It’s difficult to predict when the last chimpanzee will leave the laboratories. Some population models estimate that unless there is a significant increase in sanctuary capacity, the process could still take more than 20 years. As a result, Chimp Haven is in the process of a significant expansion effort and fundraising campaign to create new habitats and housing for at least another 100 chimpanzees in the coming years, speeding along the queue of chimpanzees awaiting retirement to sanctuary.
Collaborations are key to this progress. Working closely with the NIH and the facilities currently housing the chimpanzees, Chimp Haven is ensuring the retirement process is a positive and comfortable one for each individual chimpanzee. Likewise, they are partnering with organizations like us here at Lincoln Park Zoo, in the first zoo-sanctuary collaboration, to evaluate best practices and conduct well-being studies that can inform care of the recent retirees.
Angelo and Elmer made the nearly 800 mile journey from New Mexico to their forever home at Chimp Haven to enjoy their twilight years in repose. While it’s difficult to know for sure, they likely have some memory of the chimpanzees they’ve known that have not yet made the trip. In the coming years, the gap between laboratory and sanctuary populations will continue to widen and more chimpanzees will make their way here, finding their truest selves in this quiet forest of north Louisiana.
Footnote: The entire population of chimpanzees in the United States is carefully monitored via Lincoln Park Zoo’s Project ChimpCARE and available to the public atwww.chimpcare.org/map.
Authored by: Stephen Ross Ph.D., Director of the Lester E. Fisher Center for the Study and Conservation of Apes, Lincoln Park Zoo
In 2000, Steve was hired by Lincoln Park Zoo as a behavior specialist with a primary role in the design of what eventually became the award-winning Regenstein Center for African Apes. He conducted a wide breadth of ape and visitor studies that helped directly influence the design of the new ape facility and continues that line of research today in his applied behavioral research with chimpanzees, gorillas and Japanese macaques.
Steve served as Chair of the Chimpanzee Species Survival Plan® (SSP) from 2002-2017. In this role, he led the multi-institutional effort to manage the population of chimpanzees living in zoos accredited by the Association of Zoos and Aquariums (AZA). Steve has been instrumental in promoting the SSP as a global leader in the promotion of progressive chimpanzee management that optimizes chimpanzee welfare, both within and outside AZA zoos. He continues to serve on the elected management group of the SSP and as studbook keeper for this species.
Though Steve has published papers on species as diverse as polar bears, otters, gorillas and zoo visitors, his primary focus is improving the welfare of chimpanzees in a wide scope of conditions. His research on how the inappropriate portrayal of chimpanzees in the popular media affects public conservation attitudes of this species is a unique contribution to these efforts. These interests culminated with the initiation of Lincoln Park Zoo’s Project ChimpCARE in 2009. This innovative program seeks to assess the housing and management of chimpanzees living as pets, performers and in other private situations with the goal of facilitating policy change that will benefit this often-unseen population of chimpanzees in the United States.
With over 20 years of experience studying animal behavior, Steve is enthusiastically supportive of Lincoln Park Zoo’s approach to scientific-based decision-making. Utilizing the unique research resources available at the Lester E. Fisher Center for the Study and Conservation of Apes and the Regenstein Macaque Forest, he focuses on using science to influence policy that will have positive effects for animal welfare. Studying ape behavior and cognition allows him a unique insight into how these fascinating animals interact with their environments and how to best transform these areas to support their complex needs.