Helping to sustain the world's fish populations
Over the past several decades, wild fish stocks have rapidly depleted—even if all fishing of aquatic habitats were to cease tomorrow, it could take many years for some fish populations to fully recover. Fish ecologist Andy Danylchuk keeps fish conservation at the core of his research as he employs modern technologies to study the world’s fish populations and disseminates knowledge of best practices for conservation.
From the Bahamas to India, Danylchuk's work is in high demand—global tourism and fishing industries have taken a huge hit due to dwindling resources and stakeholders are desperate for answers. For each new project that he starts, Danylchuk conducts field research within a given aquatic ecosystem and also works with stakeholders, helping to assess the priorities of each community and then develop feasible solutions. Danylchuk explains that every location presents a different set of variables. In taking a scientific approach to a divisive issue, he investigates the reasoning behind human decisions and what impacts they have on fish and other aquatic species.
“I don’t formally do human dimensions research, but it certainly is a part of the equation since fish conservation involves understanding the motivations behind why people want or need fish,” says Danylchuk.
Andy Danylchuk conducting catch-and-release research in Puerto Rico (photo credit Shannon Bower)
Whether naturally or anthropogenically driven, ecological disturbances have a ripple effect throughout a given aquatic ecosystem. For a deeper understanding of these disturbances, Danylchuk studies the effects in terms of stress physiology, behavioral ecology, spatial ecology, predator-prey interactions, and adaptions. To understand how fish function under normal versus interrupted conditions, he uses acoustic telemetry—an emerging technology involving surgically implanted tags capable of measuring the location, depth, and activity levels of fish. In some cases this information is transmitted to remote receivers and in other cases the electronic tag is retrieved to download data related to a fish’s behavior. The technology allows Danylchuk and his team to take crucial measurements continuously from days, to months, and even years. Danylchuk combines these results with laboratory and field manipulations to determine specific causes for stress in the fish, and then uses the results to develop best practices that can reduce impacts of disturbances.
“Quantifying potential impacts using the rigors of the scientific method provides an unbiased assessment of the value of catch and release, plus gives stakeholders, including fisheries managers and government policy makers, ‘hard numbers’ that can form the foundation of conservation efforts,” Danylchuk says.
Graduate students with bonefish in Culebra, Puerto Rico
Angling—the common style of fishing that requires a hook, line and rod—is one of the most popular leisurely activities in North America as well as many other parts of the world. Because of the sheer volume of recreational anglers that regularly turn to open waters (and because many fish are caught and released), Danylchuk and his colleagues study the potential impacts related to this disturbance. Even those anglers that plan to keep their catch may have to let fish go if they are perhaps undersized or not the species they were intending to catch. Danylchuk has worked with and given talks at angling clubs around the globe to raise awareness surrounding the value of best practices for catch and release of fish. For instance, some of his collaborative research on bonefish showed that for every minute of air exposure, a fish is six times more likely to be preyed upon by a shark or barracuda when released. Not exposing fish to air, he explains, can have a huge conservation benefit, as the fish may survive and eventually contribute to the future of the population. Though seemingly simple, these techniques are important not just for the health of wild fish stocks, but to local and regional economies that rely heavily on the direct and indirect income associated with recreational angling. For example, in Massachusetts about 75 percent of recreational anglers are specifically targeting striped bass. Developing and disseminating best practices for catch and release of striped bass will therefore help support Massachusetts coastal communities, many of which have been hard hit by the demise of commercial fisheries.
Another focus of Danylchuk’s research is sustainable aquaculture. Damaging practices by commercial fisheries continue to have considerable impacts on marine ecosystems—over one quarter of United States fish stocks are overfished. Methods such as bottom trawling, an industrial fishing method that involves dragging a large, weighted net along the ocean floor, uproots entire ecosystems and results in significant collateral damage, or ‘bycatch.’ As wild stocks continue to be overexploited, and as stakeholders take steps to recover them, aquaculture will need to step in to help.
“Given the demand for seafood, we may need to turn to aquaculture to meet that demand, but not all aquaculture methods are created equal. Looking for sustainable solutions for growing fish and other aquatic life is imperative, otherwise we’re just not going to have fish to eat,” Danylchuk says.
Danylchuk discusses sustainable aquaculture with students at the Beacon of Hope school in Soroti, Uganda
Aquaculture is especially important in the developing world, where food security is an issue. Some of Danylchuk’s work is based in Sub Saharan Africa, where the transfer of sustainable aquaculture technologies and training from growing fish can help foster community development, entrepreneurship, and promote human health.
Danylchuk is also a host and scientific advisor for Fish Navy Films, a film company dedicated to making documentaries on aquatic sustainability. Danylchuk and his colleagues have produced two films and are working on a third. The first film, Fish Meat, delves into the challenges of modern fish farming and looks closely at those who are doing it efficiently and sustainably. Raising Shrimp uses shrimp, the most popular seafood in the United States, as a case study for examining the global seafood industry and the potential perils of imported versus domestic products.
For Danylchuk, outreach is crucial, which is why he devotes so much time to public speaking and film production. His work is not fully realized until it reaches as many eyes and ears (and fins) as possible.
“It goes back to the individual—the types of information that we provide them and how empowered they feel to make a difference. If they can leave a film screening, presentation, or classroom just feeling a little more informed, then I’ve done my job,” says Danylchuk.
Amanda Drane ‘12
Banner image: Close up of bonefish just caught and soon to be released.
According to Danylchuk, quantifying potential impacts gives stakeholders, including fisheries managers and government policy makers, ‘hard numbers’ that can form the foundation of conservation efforts.