Poesch, M.S., Lawrie, D., Tu, C., Jackson, D.A., and N.E. Mandrak (2012) Developing local and regional population estimates for an endangered freshwater minnow, the redside dace (Clinostomus elongatus), in Canada. Aquatic Conservation 22: 47-57.

Abstract:

The Laurentian Great Lakes have undergone drastic declines in freshwater fishes, with 22 species having become extinct in the past century and many more currently at risk. One such species is the endangered minnow, the redside dace (Clinostomus elongatus), which is undergoing severe declines across its entire range. Depletion and mark–recapture surveys were used to quantify population estimates of redside dace at several spatial scales (pool, reach and catchment) across several Great Lakes tributaries in Canada. There was large variation in the local population estimates and the rate of occurrence of redside dace populations. In some cases, such as Gully Creek, a Lake Huron tributary, redside dace were widespread (9/10 of pools) but in low abundances (13.5 individuals per pool ± 5.09 ). In other cases, such as in the Don River, redside dace were highly localized (2/27 pools) but in relatively high abundance (99.2 individuals/pool ± 18.1). Extrapolated population estimates at the catchment scale showed that three of the five study populations were below conservative estimates needed for long-term population viability. Differences in redside dace populations were driven by adjacent land-use. Post-hoc analyses revealed strong negative associations between population estimates and impervious land-use (i.e. urbanization) at both the pool and sub-catchment level. Immediate recovery actions that will focus on eliminating chronic and episodic impacts of adjacent land-use and improve connectivity are needed to help ensure redside dace, like many freshwater species in the Laurentian Great Lakes, remain a species at risk of – rather than facing – extinction.

Citation: Poesch, M.S., Lawrie, D., Tu, C., Jackson, D.A., and N.E. Mandrak. 2012. Developing local and regional population estimates for an endangered freshwater minnow, the redside dace (Clinostomus elongatus), in Canada. Aquatic Conservation 22: 47-57.

Also Read:

Neufeld, K.*, Watkinson, D., and Poesch, M.S. (2016) The effect of hydrologic alteration on capture efficiency of freshwater fishes in a highly modified Prairie stream: Implications for bio-monitoring programs. River Research and Applications 32: 975-983.

Poesch, M.S., Walker, S.C., and D.A. Jackson (2009) Functional diversity indices can be driven by methodological choices and species richness. Ecology 90(2): 341-346.

Abstract:

Functional diversity is an important concept in community ecology because it captures information on functional traits absent in measures of species diversity. One popular method of measuring functional diversity is the dendrogram-based method, FD. To calculate FD, a variety of methodological choices are required, and it has been debated about whether biological conclusions are sensitive to such choices. We studied the probability that conclusions regarding FD were sensitive, and that patterns in sensitivity were related to alpha and beta components of species richness. We developed a randomization procedure that iteratively calculated FD by assigning species into two assemblages and calculating the probability that the community with higher FD varied across methods. We found evidence of sensitivity in all five communities we examined, ranging from a probability of sensitivity of 0 (no sensitivity) to 0.976 (almost completely sensitive). Variations in these probabilities were driven by differences in alpha diversity between assemblages and not by beta diversity. Importantly, FD was most sensitive when it was most useful (i.e., when differences in alpha diversity were low). We demonstrate that trends in functional-diversity analyses can be largely driven by methodological choices or species richness, rather than functional trait information alone.

Citation: Poesch, M.S., Walker, S.C., and Jackson, D.A. 2009. Functional diversity indices can be driven by methodological choices and species richness. Ecology 90(2): 341-346.

Also Read:

Theis, S.*, Ruppert, J.*, Shirton, J.* and M.S. Poesch (2022) Measuring beta diversity components and beneficial effects of coarse woody habitat introduction on invertebrate and macrophyte communities in a shallow northern boreal lake: implications for offsetting. Aquatic Ecology 56: 793-814.

Poesch, M.S., Mandrak, N.E., and R. L. McLaughlin (2008) A practical framework for selecting among single species, multi-species and ecosystem-based recovery plans. Canadian Journal for Fisheries & Aquatic Science 65: 2656-2666.

Abstract:

Science-based approaches for selecting among single-species, community-, and ecosystem-based recovery plans are needed to conserve imperilled species. Selection of recovery plans has often been based on past success rates with other taxa and systems or on economic cost, but less on the ecology of the system in question. We developed a framework for selecting a recovery plan based on the distributions and ecology of imperilled and nonimperilled species across available habitat types and applied it to fishes in the Sydenham River, Ontario, Canada. We first tested whether distributions of fishes were adequately predicted by habitat features hypothesized to limit the distributions of imperilled fishes versus a broader set of habitat features known to predict fish distributions. We then tested whether imperilled species occurred in similar or disparate habitat types. For the Sydenham River, an ecosystem-based recovery plan was deemed most appropriate because imperilled species occur in disparate habitat types. We lastly provide decision criteria to facilitate applications of our framework to the selection of recovery plans for other species and systems.

Citation: Poesch, M.S., Mandrak, N.E., and McLaughlin, R.L. 2008. A practical framework for selecting among single species, multi-species and ecosystem-based recovery plans. Canadian Journal for Fisheries & Aquatic Science 65: 2656-2666.

Also Read:

Castaneda, R.A., Ackerman, J.D., Chapman, L.J., Cooke, S.J., Cuddington, K., Dextrase, A., Jackson, D.A., Koops, M.A., Krkosek, M., Loftus, K., Mandrak, N.E., Martel, A.L., Molnar, P., Morris, T.J., Pitcher, T.E., Poesch, M.S., Power, M., Pratt, T.C., Reid, S.M., Rodriguez, M.A., Rosenfeld, J., Wilson, C., Zanatta, D.T. and D.A.R. Drake. (2021) Approaches and research needs for advancing the protection and recovery of imperilled freshwater fishes and mussels in Canada. Canadian Journal of Fisheries and Aquatic Sciences 78 (9): 1356-1370.

Walker, S., Poesch, M.S. and D. A. Jackson. (2008) Functional rarefaction: Estimated functional diversity from field data. Oikos 117(2): 286-296.

Abstract:

Studies in biodiversity-ecosystem function and conservation biology have led to the development of diversity indices that take species’ functional differences into account. We identify two broad classes of indices: those that monotonically increase with species richness (MSR indices) and those that weight the contribution of each species by abundance or occurrence (weighted indices). We argue that weighted indices are easier to estimate without bias but tend to ignore information provided by rare species. Conversely, MSR indices fully incorporate information provided by rare species but are nearly always underestimated when communities are not exhaustively surveyed. This is because of the well-studied fact that additional sampling of a community may reveal previously undiscovered species. We use the rarefaction technique from species richness studies to address sample-size-induced bias when estimating functional diversity indices. Rarefaction transforms any given MSR index into a family of unbiased weighted indices, each with a different level of sensitivity to rare species. Thus rarefaction simultaneously solves the problem of bias and the problem of sensitivity to rare species. We present formulae and algorithms for conducting a functional rarefaction analysis of the two most widely cited MSR indices: functional attribute diversity (FAD) and Petchey and Gaston’s functional diversity (FD). These formulae also demonstrate a relationship between three seemingly unrelated functional diversity indices: FAD, FD and Rao’s quadratic entropy. Statistical theory is also provided in order to prove that all desirable statistical properties of species richness rarefaction are preserved for functional rarefaction.

Citation: Walker, S., Poesch, M.S. and Jackson, D.A. 2008. Functional rarefaction: Estimated functional diversity from field data. Oikos 117(2): 286-296.

Also Read:

Banting, A.*, Vinebrooke, R., Taylor, M., Carli, C. and M.S. Poesch. (2021) Impacts of a regionally-native predator on littoral macrobenthos in fishless mountain lakes: implications for assisted colonization. Conservation Science and Practice 3(2): e344.

Poesch, M.S., Mandrak, N.E., and R. L. McLaughlin (2007) The effectiveness of two common sampling methods for sampling imperiled freshwater fishes. Journal of Fish Biology 70: 691-708.

Abstract:

This study tested the hypothesis that the most common gear type used to sample fishes in wadeable systems, electrofishing, was more effective than another commonly used gear type, seining, for sampling fish species at risk. Five predictions were tested. At sites where species at risk were detected, (1) the probability of detecting the species at risk, (2) the probability of only one gear type detecting the species at risk and (3) the estimated catch per unit effort of the species at risk, was as high as, or higher, when using electrofishing than when using a seine. (4) The number of sample sites required to detect a species at risk within a watershed and (5) the number of subsections required to detect a species at risk within a site, were as low as, or lower, using electrofishing than the number required using a seine. Based on analyses of these measurements, electrofishing was a more effective gear type than seining for sampling fish species at risk, irrespective of the unit (presence or absence or catch per unit effort) or scale of measurement (watershed or site level). Dissolved oxygen, turbidity, specific conductivity and nitrate concentrations were measured at each site and did not account for the between gear differences. Selection of sampling gear can be a fundamental consideration for the assessment of fish species at risk, where, unlike common species, they may be particularly influenced by small population sizes, restricted geographic ranges and narrow habitat preferences. Resource managers must weigh differences in the risks of injury of fish species at risk against differences in the effectiveness of each gear type when deciding between gear types and the utility of the assessments they represent.

Citation: Poesch, M.S., Mandrak, N.E., and McLaughlin, R.L. 2007. The effectiveness of two common sampling methods for sampling imperiled freshwater fishes. Journal of Fish Biology 70: 691-708.

Also Read:

Neufeld, K.*, Watkinson, D., and Poesch, M.S. (2016) The effect of hydrologic alteration on capture efficiency of freshwater fishes in a highly modified Prairie stream: Implications for bio-monitoring programs. River Research and Applications 32: 975-983.