Catostomid fishes are a diverse family of 76+ freshwater species that are distributed across North America in many different habitats. This group of fish is facing a variety of impacts and conservation issues that are somewhat unique relative to more economically valuable and heavily managed fish species. Here, we present a brief series of case studies to highlight the threats such as migration barriers, flow regulation, environmental contamination, habitat degradation, exploitation and impacts from introduced (non-native) species that are facing catostomids in different regions. Collectively, the case studies reveal that individual species usually are not threatened by a single, isolated factor. Instead, species in general face numerous stressors that threaten multiple stages of their life history. Several factors have retarded sucker conservation including widespread inabilities of field workers to distinguish some species, lack of basic natural history and ecological knowledge of life history, and the misconception that suckers are tolerant of degraded conditions and are of little social or ecological value. Without a specific constituent group lobbying for conservation of non-game fishes, all such species, including members of the catostomid family, will continue to face serious risks because of neglect, ignorance, and misunderstanding. We suggest that conservation strategies should incorporate research and education/outreach components. Other conservation strategies that would be effective for protecting suckers include freshwater protected areas for critical habitat, restoration of degraded habitat, and design of catostomid-friendly fish bypass facilities. We believe that the plight of the catostomids is representative of the threats facing many other non-game freshwater fishes with diverse life-history strategies globally.
Identification of critical habitat is a key step in conservation and recovery of endangered and threatened freshwater fish. Critical habitat under Canadian and US legislation may include habitat that is not directly used by listed fish, provided it is necessary for species conservation or recovery. Riparian habitat meets biological criteria for critical habitat because riparian zones are integral to aquatic ecosystem functions of importance to many fish species and other organisms. These functions include provision of shade for temperature-sensitive species, control of channel complexity and sediment inputs through bank stabilization, input of large wood and allochthonous energy sources, and filtering of nutrients and tox- ins from adjacent land. In response to decades of stream-riparian research, widespread implementation of regulations to protect riparian zones in most developed countries represent a de facto consensus that riparian buffers are essential for aquatic ecosystem health and the maintenance of populations of fish and other species. Consistent with widespread riparian regulations deemed necessary to protect not-at-risk species, riparian habitat adjacent to a body of water containing a listed freshwater species should be considered biologically critical unless the habitat requirements of individual taxa are demonstrated to be insensitive to the ecological functions associated with riparian habitat.
This most comprehensive and authoritative book on the subject; nothing else comes close. McPhail is Professor Emeritus of Zoology at UBC and is widely regarded as the leading expert on the topic. The book is scientifically rigorous, but quite accessible to the lay reader.
A searchable online database that provides data summaries on species occurrences, fish stocking, migration barriers, salmon spawner counts and many other topics by watershed. It also shows reports and data in government files. Data can be downloaded in spreadsheet form. The ‘Single Waterbody’ query is usually the most useful. This is what professionals use to research what is known about a particular waterbody.
A comprehensive key to identification of BC freshwater fishes, including introduced species.
EXCERPT: This set of keys is an attempt to provide rapid and dependable field identifications of BC freshwater fish. Traditional keys are not veryuseful in the field, since they are designed for use on preserved specimens – a definite drawback when working with rare or threatened species. Because field identifications are essential in inventory work, we’ve tried to design keys that work in the field. To this end we have included information that is rarely incorporated in traditional keys. For example, information on where a fish was caught (both the geographic locality and site-specific habitat) and what it looks like when alive, can make the identification of even complex species groups easy. For instance, sculpins (“bullheads” of the genus Cottus) are notoriously difficult to identify. In most keys you have to examine chin pores, make judgements about tubular nostrils and the degree of separation of the dorsal fins, as well as count dorsal, anal and pectoral fin rays, and determine if there are palatine teeth, before you can make an identification. In many cases this detail is unnecessary. First, there is no place in BC where all seven of our Cottus species coexist. Since there are only two or three species in
most drainage systems, as long as you know where you are there is no need to work through a key that includes all seven species. Also, many sculpin species have distinctive life-colours and usually occur in specific habitats. Consequently, geographic locality, together with habitat and colour pattern, often are enough for a reliable field identification.