Photo credit: Paul Kusnierz
INTRODUCTION
Poor water quality is one of the greatest threats to fish population recovery, fisheries, and aquaculture. There are examples of game fish species and species of conservation concern threatened by poor water quality conditions across North America (Warren and Burr 1994; Couillard et al. 2008). In the Missouri River–Fort Peck Reservoir, low dissolved oxygen limits Pallid Sturgeon Scaphirhynchus albus larvae survival (Guy et al. 2015). In the Pacific Northwest, increased temperatures reduce habitat for salmonids (Isaak and Rieman 2013). In the Northeast, acid deposition threatens populations of native Brook Trout Salvelinus fontinalis and endangered Atlantic Salmon Salmo salar (Parrish et al. 1998; Baldigo et al. 2007). The population of White Sturgeon Acipenser transmontanus in Brownlee Reservoir, Idaho, is one example of a species of conservation concern that has sufficient, otherwise suitable habitat, but has not recovered due to extended hypoxia resulting from agricultural runoff (Sullivan et al. 2003).
Water quality can also be an issue for hatcheries and when introducing hatchery‐raised fish into the wild. An estimated 200,000–300,000 fall Chinook Salmon Oncorhynchus tshawytscha smolts were killed in an incident at a California hatchery because debris from a spillway failure caused oxygen levels to drop (Cahill 2017). Recently, the Idaho Department of Fish and Game in collaboration with National Marine Fisheries Service researchers discovered that low survival of endangered, hatchery‐reared Sockeye Salmon O. nerka smolts was the result of differences in water hardness between the hatchery and the release site (Trushenski et al. 2019). In each of these situations, desired fisheries goals cannot be achieved without addressing underlying water quality issues.
It is readily apparent that fish must have clean water to survive and that when water quality is severely degraded, fish populations typically suffer. However, in some cases, a waterbody can be considered to have impaired water quality, yet be highly productive from a fisheries standpoint (see Stockner et al. 2000 and Anders and Ashley 2007 for further discussion of this topic). To ensure that protective water quality is maintained while fisheries are effectively managed, we believe that better collaboration is needed between fisheries and water quality professionals. In this perspective column, we make a case that these two groups of professionals can be more effective by working together and sharing perspectives. We highlight the benefits of such partnerships and describe specific opportunities for strengthening collaboration. Finally, we highlight the role that the American Fisheries Society can play by facilitating collaboration through professional meetings and training.
BREAKING DOWN THE SILOS
For the purposes of this perspective, fisheries professionals are broadly defined to include individuals that manage fish populations and their habitat or that are involved with aquaculture and stocking. Similarly, we broadly define water quality professionals as individuals concerned with surface water quality as it relates to the federal Clean Water Act of 1974 and/or state legislation and regulations concerning the improvement and maintenance of water quality for the benefit of aquatic biota. Those conducting research or aquatic habitat restoration are considered under these definitions. We do not intend to exclude any group of fisheries or water quality professionals, rather these definitions are coarse descriptions of positions that we see as having essential roles fostering this type of collaboration.
Speaking in general terms, these two types of professionals typically work in distinct spheres: fisheries professionals study and manage specific organisms while water quality professionals evaluate and manage the chemical and sometimes physical conditions of the waters in which organisms live. This separation into distinct specialties may be driven by agency mission, academic funding, or individual assignments or preferences. Fisheries professionals are responsible for monitoring physical attributes, surveying the geographic distribution and population size, protecting or restoring fish habitat with the goal of maintaining or enhancing population demographics, and managing harvest. Typical methods to achieve these goals include the establishment of angling regulations; active management through stocking, removal, and encouraging harvest; and manipulation of community dynamics through predator and prey control or removal of invasive species.
By contrast, water quality professionals customarily focus on the quantification of chemical constituents or physical habitat and subsequent comparison against thresholds that are indicators of biotic health. When aquatic communities are explicitly considered, thresholds are often based on protecting 95% of individuals exposed to a contaminant (Grist et al. 2002; Cormier and Suter 2013; van Dam et al. 2014). However, the most sensitive or commercially, recreationally, or environmentally important species (e.g., Endangered Species Act listed species) can drive the selection of the protective thresholds. Achieving stated goals often occurs through pollutant reduction, implementation of best management practices (e.g., off stream watering for cattle), or improving waterbody form and function (e.g., reconnecting floodplain access), not through the direct manipulation of aquatic organisms. In addition, water quality professionals are concerned with multiple beneficiaries including domestic (e.g., drinking water) and recreational users (e.g., swimmers; Munns et al. 2016) as well as fishes (Forbes et al. 2019). Because of the fundamentally different approaches of these two groups, each is more likely to work with peers sharing similar educational and professional backgrounds and there is the potential to become narrowly focused.
We recognize that overlap in knowledge base between fisheries and water quality professionals does occur and that in some cases consultation between the two professions is required (such as in California [CA WAT § 1243]). And although professionals in both fields may share knowledge in the same domain (e.g., water temperature and its importance to fish), each has a unique perspective on the implications for different resources. When this type of overlap occurs, the benefits of creating opportunities for the professionals from all relevant disciplines to be seated at the table should be considered. Taking this approach from the beginning provides the opportunity for each professional to develop an awareness of potential unforeseen pitfalls outside of their area of direct scientific expertise.
There are many areas where the disciplines of fisheries and water quality readily intersect; for example, stream habitat restoration, consultation for hydropower licensing, and public education all share this nexus. One area of significant overlap for both groups is interaction with the public. Public interaction might involve presenting at public meetings or engaging in working groups involving multiple stakeholders. Whereas many of these interactions may be innocuous, some can be confrontational. Both types of professional can be found in the field collecting data or implementing field projects. Both share knowledge about how to obtain permission from landowners to access sampling sites. The experiences of fisheries professionals proposing and implementing new fishing regulations and stocking regimes, and water quality professionals publicly communicating the purpose of total maximum daily loads and working with watershed groups to develop stream restoration projects and watershed plans provide a wealth of experience from each to learn from the other. Dialog between these two groups about interactions with the public, both positive and negative, can lead to more effective communication between those managing aquatic resources and those utilizing them.
Better collaboration between these two groups of professionals could lead to a more holistic approach to managing aquatic resources that considers a broader set of solutions and improved outcomes (e.g., ecosystem‐based management in the Great Lakes [Guthrie et al. 2019]). Such a holistic approach is likely to produce significant benefit to stream habitat restoration where actions such as reconnecting stream floodplains to diversify fish habitat (Waples et al. 2009) also has the potential to improve water quality (Forshay and Stanley 2005). Including fisheries professionals when planning river restoration projects with explicit water quality goals is likely to result in changes that will benefit both water quality and aquatic biota. For example, fisheries professionals are more likely to understand species‐specific tolerances to stressors and the seasons when risk is greatest (e.g., water temperature during spawning). Similarly, the inclusion of water quality professionals can improve effectiveness of fish habitat restoration projects by incorporating pollution reduction measures, resulting in more benefits to aquatic resources and potentially reducing the frequency of project maintenance. These benefits are not necessarily the result of compensating for one professional's ignorance of the other's field; rather, it is the result of professional experiences and connections they have developed. By sharing expertise, increasing shared knowledge, and expanding the toolkit, we can expect problems in aquatic resource management to be addressed more effectively.
Moving forward, collaboration between fisheries and water quality professionals will be especially important when dealing with some of the emerging issues in fisheries that have a strong water quality nexus (see Boxes 1–3).
The presence of pharmaceuticals (e.g., estrogen and estrogen‐disrupting compounds, anticonvulsant, psychiatric, and antibiotic drugs) in surface waters and effluent from sewage treatment plants has been a concern for at least 2 decades (Daughton and Ternes 1999). More recently, concerns have emerged about antimicrobials used in animal feedlot operations (Snow et al. 2015) and aquaculture (Justino et al. 2016). These compounds are frequently detected in municipal wastewater effluent as well as in agricultural runoff in rural areas (Tillitt and Buxton 2012; Liu et al. 2015) and have potential adverse consequences for fish populations and humans that consume them.
Pharmaceuticals have been identified in fish tissues, demonstrating bioaccumulation (Meador et al. 2017) and the potential for effects throughout the aquatic food chain. For example, a whole inland lake study of the synthetic estrogen 17α‐ethynyloestradiol in Ontario, Canada, determined that small‐bodied fishes were most affected, and that indirect effects cascaded through the aquatic food web affecting the top predator (Lake Trout Salvelinus namaycush), as well as zooplankton (Kidd et al. 2014). The long list of pharmaceutical effects on fishes includes changes in time spent swimming versus in refuge (Brandao et al. 2013), embryonic development (Schubert et al. 2014), gene expression (Gunnarsson et al. 2009; Jeffries et al. 2015), and feeding (Brodin et al. 2013; Hedgespeth et al. 2014), as well as metabolic disruption (Meador et al. 2018), reproductive failure (Nash et al. 2004), population collapse (Kidd et al. 2007), and change in assemblage structure (Sanchez et al. 2011).
Whereas much has been learned about the effects of pharmaceuticals on aquatic fauna, more research is needed to help address the presence of these chemicals in aquatic ecosystems (Miller et al. 2018). Understanding the organismal and population‐level effects of pharmaceuticals, identifying those that are most ecologically harmful, and ultimately developing strategies for reducing their presence and impact on receiving waterbodies will require expertise from many disciplines. Strong collaboration and leadership from water quality and fisheries professionals can provide the foundation for this process.
The use of plastics has spread worldwide and is now causing problems by contaminating water used by humans, fishes, and other organisms (Andrady 2011). Extensive quantities of plastic debris in the ocean pose dangers to fish and marine mammals that ingest them and have been studied for some time (Carbery et al. 2018). Only recently are we coming to understand the threat to freshwaters and coastal waters that support fisheries and aquaculture operations (Au et al. 2017).
Human consumption appears inevitable as microplastics have been detected in samples of treated wastewater and in our food supply. Concentrations in treated wastewater are high. One study in the Czech Republic found microplastics in 100% of collected wastewater samples, with the majority comprised of polyethylene terephthalate, polypropylene, and polyethylene, chemicals used widely in consumer goods and packaging (Pivokonsky et al. 2018). Examination of microplastics in coastal aquaculture of mussels has revealed uptake of microplastic fibers (Li et al. 2018; Renzi et al. 2018). Reported ecotoxicological effects on aquatic organisms such as fishes include reduced feeding activity, growth, reproductive fitness, and neurotoxicity and death (De Sá et al. 2018). Microplastic levels in groundwater have thus far been low (Mintenig et al. 2019).
By working together, fisheries (including aquaculture and conservation) professionals and water quality experts will be better able to address this emerging threat from microplastics. Future needs may include upstream and downstream interventions. Upstream, there is a need to promote a circular economy whereby biodegradable plant‐based, rather than petroleum‐based, products (i.e., plastics) are used (Rhodes 2018). Downstream, advanced detection methods, modeling and laboratory testing to quantify risk to fish and invertebrate species, and improved filtration systems for aquaculture and wastewater treatment facilities are needed.
Urbanization can significantly alter the physical and chemical properties of watersheds. As urban areas expand, the extent of impervious (paved) surface is increasing. Typical watershed effects include lower base flow, flashy flows dominated by stormwater (i.e., increased frequency of over‐bank flow), reduced shading and instream cover, substrate coarsening, increased pollutant loading, and a shift to more tolerant aquatic biota (Klein 1979; Finkenbine et al. 2000). To date, most research has focused on physical impacts such as loss of pervious surfaces and changes in channel form that reduce sinuosity and floodplain access (e.g., Booth and Jackson 1997). However, pollutants in stormwater can result in diverse and significant impacts on fishes in receiving waters ranging from olfactory impairment (Sandahl et al. 2007), and organ malformation (McCarthy et al. 2008; McIntyre et al. 2014) to mortality (Scholz et al. 2011; Feist et al. 2018). Although stormwater can be treated to reduce its impacts (Hsieh and Davis 2005), discharge volumes during storms are unpredictable and may exceed capacity of treatment facilities (Booth and Jackson 1997).
Poor water quality in urban areas is especially unfortunate because the potential for people to fish and enjoy river ecosystems is highest in areas with high population densities. Keys to maximizing such opportunity will be the result of redesigning urban watersheds to increase the ecosystem services that rivers and lakes provide to urbanites and managing drainage in cities to support healthy aquatic populations. Addressing the growing impact of urban stormwater requires the inclusion of the combined expertise of water quality experts and fisheries professionals. In planning new developments or retrofitting existing stormwater treatment systems, collaboration and coordination by water quality and fisheries professionals throughout the planning process will be vital to improving habitat quality for aquatic biota.
EMERGING WATER QUALITY THREATS TO FISHERIES
Although existing regulations, such as the Clean Water Act, have been successful in addressing water quality problems, several important water quality issues that threaten fish populations and other water users are on the horizon (Gavrilescu et al. 2015). These include contamination of water by pharmaceuticals (Box 1) and microplastics (Box 2), and the threat increased urbanization poses to water chemistry and temperature (Box 3). Exacerbating these issues are the effects of climate change on water quality (Chen et al. 2016). Differing approaches will be necessary to address these distinct threats (e.g., pretreatment for pharmaceuticals and microplastics versus land use planning and effective stormwater management for urbanization), and will provide opportunities to develop stronger collaboration between fisheries and water quality professionals.
CONCLUSION
Adequate water quality is a prerequisite for achieving goals of fishery management and aquatic conservation (Grimm 1989). To this end, it is important to establish and maintain working relationships between professionals in the fields of water quality and fisheries. We encourage fisheries professionals to participate in meetings of water quality‐focused organizations. For example, the Society of Environmental Toxicology and Chemistry provides a forum for researchers seeking to discover how fishes and other aquatic taxa respond to contaminants. The American Water Resources Association and state water quality agencies are other examples of professional organizations for water quality experts. Meetings organized by these entities provide opportunities to ask questions and learn about water quality management and to provide a fisheries perspective.
The Water Quality Section of the American Fisheries Society (AFS) is an organization that can bring these two interconnected fields together. We encourage both water quality and fisheries professionals to join and become involved in the Water Quality Section. We ask that fisheries professionals encourage colleagues who are experts in water quality and ecotoxicology to attend AFS meetings, contribute posters and presentations, and learn about the biological communities that are the ultimate beneficiaries of water quality improvements.
The Water Quality Section is actively planning symposia at the nexus of the two fields and opportunities exist for participating in water quality symposia each year at AFS Annual Meetings. The section sponsored two symposia at the 2018 meeting in Atlantic City, New Jersey. The first was a half‐day symposium entitled “Bad Acid: Past and Future Risk of Acidification to Aquatic Ecosystems that Support Fisheries and Aquaculture.” This session included 10 presentations, roughly half devoted to ocean acidification and the other half on the topic of freshwater acidification. Topics included effects on sensory function in marine organisms, effects on mollusks and implications for coastal aquaculture, reduced acidification resulting from the passage of the 1990 Clean Air Act amendment in the eastern United States, acid mine drainage, and impacts on fish and recovery of aquatic communities. The Section also sponsored a second symposium entitled “Landscape Influences on Stream Habitats and Biological Assemblages” and is helping to sponsor the second edition of an edited book by this title. In addition, at the 2018 Western Division AFS meeting in Anchorage, Alaska, the Section sponsored a half‐day symposium titled “Water Quality in Fisheries: Keeping an Eye on a Vital Resource.” Presentations covered the ecological impacts of mining and urbanization, the relationships between water chemistry and Sockeye Salmon production and survival, and gas bubble disease resulting from high total dissolved gas levels in water spilled over a dam. In 2019, the Section co‐sponsored two symposia at the joint meeting with The Wildlife Society in Reno, Nevada. The first was a 2‐day symposium “Fire Resilience: Can Fish, Wildlife, and Humans Adapt to Shifts in Wildfire Disturbance?” The second symposium was entitled “Natural Resource Conservation in Intensively Managed Agricultural Landscapes.”
With help from our fellow AFS members, we can expand the Water Quality Section, further bridge the gap between water quality and fisheries professionals, and create better outcomes in our fisheries management that will benefit many generations to come.
ACKNOWLEDGMENTS
This manuscript was improved thanks to the comments of Eric Oldenburg and an anonymous reviewer. Co‐author Henriette I. Jager's contribution was supported by Oak Ridge National Laboratory, which is managed by UT‐Battelle, LLC. for the U.S. Department of Energy under Contract No. DE‐AC05‐00OR22725. The U.S. government retains and the publisher, by accepting the article for publication, acknowledges that the U.S. government retains a non‐exclusive, paid‐up, irrevocable, world‐wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for U.S. government purposes. The U.S. Department of Energy will provide public access to the results of federally sponsored research in accordance with its Public Access Plan (available: http://bit.ly/39CmwYd). There is no conflict of interest declared in this article.
