Richard D. Clark

Bio: Richard D. Clark is an academic researcher from Michigan State University. The author has contributed to research in topics: Salmo & Trout. The author has an hindex of 11, co-authored 16 publications receiving 529 citations. Previous affiliations of Richard D. Clark include Michigan Department of Natural Resources.

Range, Activity, and Habitat of Large, Free‐Ranging Brown Trout in a Michigan Stream

Abstract: Little is known about behavior patterns and habitat use of large (400+ mm total length) brown trout Salmo trutta. We used radio telemetry to monitor the movements of eight large (437–635 mm), free-ranging brown trout for up to 346 d. Total range of movement upstream and downstream varied from 370 m to 33,420 m. At some time during the year, six of the fish moved out of an area protected with no-kill fishing regulations, even though none of them were tagged and released closer than 2 km from its boundaries. However, four of five fish tracked during the height of the fishing season spent 87% of their time in the protected area. The fish appeared to have separate winter and summer ranges. Five of six fish tracked during autumn–winter moved upstream about 10 km to slower, deeper parts of the river between August and November, and remained there at least through the following April. The part of the river used as autumn–winter range was considered only marginal habitat for brown trout during summer due...

Potential Effects of Voluntary Catch and Release of Fish on Recreational Fisheries

Abstract: Anglers frequently release fish that are large enough to keep under prevailing fishing laws. However, fisheries managers usually estimate only fishing effort and number of fish harvested when assessing a fishery, and simply assume this voluntary release of fish is unimportant. In this study, I examined how the release of legal fish might affect a fishery. I modified the classical yield-per-recruit model so that the total mortality rate (Z) was partitioned into three components: natural (M), fishing (F), and hooking (H) mortality rates. I used another parameter (p), representing the probability a legal fish was released when captured, to modify the levels of fishing and hooking mortality. I applied the model to four fisheries with widely different characteristics of growth, mortality, and fishing: brook trout (Salvelinus fontinalis) in a small stream, largemouth bass (Micropterus salmoides) in a medium-sized reservoir, brown trout (Salmo trutta) in a medium-sized river, and northern pike (Esox luc...

A spatially constrained clustering program for river valley segment delineation from GIS digital river networks

Abstract: River valley segments are adjacent sections of streams and rivers that are relatively homogeneous in hydrology, limnology, channel morphology, riparian dynamics, and biological communities. River valley segments have been advocated as appropriate spatial units for assessing, monitoring, and managing rivers and streams for several reasons; however, methods for delineating these spatial units have been tedious to implement or have lacked objectivity, which arguably has limited their use as river and stream management units by natural resource agencies. We describe a spatially constrained clustering program that we developed for delineating river valley segments from geographic information system digital river network databases that is flexible, easy-to-use, and improves objectivity in the river valley segment delineation process. This program, which we refer to as the valley segment affinity search technique (VAST), includes a variety of options for determining spatial adjacency in stream reaches, as well as several data transformation methods, types of resemblance coefficients, and cluster linkage methods. The usefulness of VAST is demonstrated by using it to delineate river valley segments for river network databases for Michigan and Wisconsin, USA, and by comparing river valley segments delineated by VAST to an expert-opinion delineation previously completed for a Michigan river network database.

Movement Patterns of Large Brown Trout in the Mainstream Au Sable River, Michigan

Abstract: We used radiotelemetry to monitor spring and summer movements of 11 brown trout Salmo trutta (442–584 mm) for up to 904 d in a Michigan stream. Individual brown trout used a few specific locations near cover (referred to as home sites) as resting locations during the day, moved across various distances at night, and generally returned to the same home site the next morning. Home sites were predominantly artificial cover (88%) rather than natural sites, as natural cover was very limited in the study area. Some fish used multiple home sites, and the average separation between multiple home sites for individual fish was over 500 m. Fish tracked for more than 1 year used the same home sites each summer and generally exhibited similar behavior each year. Fish belonged to two general categories of daily movement behavior: mobile or stationary. Mobile fish tended to move frequently and were found within their home sites only 43% of the time at night. Stationary fish did not move far from home sites, eve...

Documented and Potential Biological Impacts of Recreational Fishing: Insights for Management and Conservation

Abstract: While the impacts of high exploitation on fish populations and aquatic ecosystems are well-documented for commercial fishing, particularly in the marine environment, the potential biological impacts of angling received less attention. This paper discusses angling patterns within a framework of basic ecological and evolutionary literature and examines potential biological impacts of angling by focusing on study results associated with high exploitation rates and pronounced selective exploitation. The impacts range from impacts occurring directly on the exploited species (truncation of the natural age and size structure, depensatory mechanisms, loss of genetic variability, evolutionary changes), to those that occur on the aquatic ecosystem (changes in trophic cascades, trait-mediated effects). As a third category, impacts related to the angling activity per se are distinguished (habitat modifications, wildlife disturbance, nutrient inputs, loss of fishing gear). Although the main threats to fish often are l...

Understanding the Complexity of Catch-and-Release in Recreational Fishing: An Integrative Synthesis of Global Knowledge from Historical, Ethical, Social, and Biological Perspectives

Abstract: Most research on catch-and-release (C&R) in recreational fishing has been conducted from a disciplinary angle focusing on the biological sciences and the study of hooking mortality after release. This hampers understanding of the complex and multifaceted nature of C&R. In the present synopsis, we develop an integrative perspective on C&R by drawing on historical, philosophical, socio-psychological, biological, and managerial insights and perspectives. Such a perspective is helpful for a variety of reasons, such as 1) improving the science supporting successful fisheries management and conservation, 2) facilitating dialogue between managers, anglers, and other stakeholders, 3) minimizing conflict potentials, and 4) paving the path toward sustainable recreational fisheries management. The present work highlights the array of cultural, institutional, psychological, and biological factors and dimensions involved in C&R. Progress toward successful treatment of C&R might be enhanced by acknowledging the complex...

Hooking mortality: A review for recreational fisheries

Abstract: Length‐limit regulations and promotion of catch‐and‐release fishing have become increasingly important management approaches for recreational fisheries. We review‐studies on catch‐and‐release (hooking) mortality gathered from the existing fisheries literature and from a survey of fisheries management agencies in all 50 states, the U.S. government, all Canadian provinces, and selected academic and research institutions. We identified hooking mortality estimates for 32 taxa. Most studies dealt with salmonids, centrarchids (especially black basses, Micropterus spp.), and percids (especially walleye, Stizostedion vitreum). Within and among species, differences in percent mortality were reported in association with bait type (artificial vs. natural), hook type (number of hooks, hook size, and barbs), season/ temperature, water depth (depressurization), anatomical location of hook wound, and individual size. Although most hooking mortalities occur within 24 h, the use of initial plus delayed mortality ...

Restricted Movement in Resident Stream Salmonids: A Paradigm Lost?

Abstract: Gerking (1959 Biol Rev 34: 221–242) proposed a theory about the restricted movement of stream fishes that may be considered a paradigm in salmonid biology The restricted movement paradigm (our

Winter habitat of selected stream fishes and potential impacts from land-use activity

Abstract: This paper reviews the habitat characteristics and the behaviour of selected stream fishes during winter in temperate-boreal ecosystems. Emphasis is placed on the salmonid fishes upon which most winter research has been directed. As space is the primary factor regulating stream fish populations in winter, aspects of winter habitat are considered at various spatial scales from microhabitat to stream reach to river basin. Choice of winter habitat is governed by the need to minimize energy expenditure, with the main criterion being protection from adverse physicochemical conditions (e.g., ice, spates, low oxygen). The distance moved to wintering habitats, and the continued activity by many fishes during winter, need to be considered when making management decisions regarding fish habitat. How habitat is affected by land-use activity in stream catchments is discussed with reference to impacts from water withdrawal, varying discharge regimes, and erosion or sedimentation. Even stream "enhancement" practices can deleteriously affect fish habitat if project managers are unaware of winter habitat requirements and stream conditions. Maintenance of habitat complexity, at least at the scale of stream sub-basin, is recommended to ensure the diversity of winter habitats for fish communities. Resume : Le document fait l'examen des caracteristiques de l'habitat et du comportement de certains poissons de cours d'eau pendant l'hiver en ecosystemes temperes ou boreaux. L'accent est mis sur les salmonides qui ont fait l'objet de la plus grande partie des recherches effectuees en hiver. L'espace etant le premier facteur regissant les populations de poissons de cours d'eau en hiver, les aspects de l'habitat d'hiver sont examines en fonction de diverses echelles spatiales allant du micro-habitat, au segment et au bassin du cours d'eau. Le choix de l'habitat d'hiver est regi par le besoin de minimiser les depenses energetiques et a pour critere principal la protection contre les conditions physiques et chimiques adverses (glaces, crues, faible teneur en oxygene). La distance parcourue pour atteindre les habitats d'hivernage et le maintien de l'activite d'un grand nombre de poissons pendant l'hiver doivent etre pris en compte au moment de la prise de decisions de gestion