Survival and Selection of Migrating Salmon from Capture-Recapture Models with Individual Traits

Capture–recapture studies are powerful tools for studying animal population dynamics, providing information on population abundance, survival rates, population growth rates, and selection for phenotypic traits. In these studies, the probability of observing a tagged individual reflects both the probability of the individual surviving to the time of recapture and the probability of recapturing an animal, given that it is alive. If both of these probabilities are related to the same phenotypic trait, it can be difficult to distinguish effects on survival probabilities from effects on recapture probabilities. However, when animals are individually tagged and have multiple opportunities for recapture, we can properly partition observed trait-related variability into survival and recapture components. We present an overview of capture–recapture models that incorporate individual variability and develop methods to incorporate results from these models into estimates of population survival and selection for phenotypic traits. We conducted a series of simulations to understand the performance of these estimators and to assess the consequences of ignoring individual variability when it exists. In addition, we analyzed a large data set of .153 000 juvenile chinook salmon (Oncorhynchus tshawytscha) and steelhead (O. mykiss) of known length that were PIT-tagged during their seaward migration. Both our simulations and the case study indicated that the ability to precisely estimate selection for phenotypic traits was greatly compromised when differential recapture probabilities were ignored. Estimates of population survival, however, were far more robust. In the chinook salmon and steelhead study, we consistently found that smaller fish had a greater probability of recapture. We also uncovered length-related survival relationships in over half of the release group/river segment combinations that we observed, but we found both positive and negative relationships between length and survival probability. These results have important implications for the management of salmonid populations

A comprehensive approach for habitat restoration in the Columbia Basin

The Columbia Basin once supported a diversity of native fishes and large runs of anadromous salmonids that sustained substantial fisheries and cultural values. Extensive land conversion, watershed disruptions, and subsequent fishery declines have led to one of the most ambitious restoration programs in the world. Progress has been made, but restoration is expensive (exceeding US $300 M/year), and it remains unclear whether habitat actions, in particular, can be successful. A comprehensive approach is needed to guide cost-effective habitat restoration. Four elements that must be addressed simultaneously are (1) a scientific foundation from landscape ecology and the concept of resilience, (2) broad public support, (3) governance for collaboration and integration, and (4) a capacity for learning and adaptation. Realizing these in the Columbia Basin will require actions to rebalance restoration goals to include diversity, strengthen linkages between science and management, increase public engagement, work across traditional ecological and social boundaries, and learn from experience.This is the publisher’s final pdf. The published article is copyrighted by Taylor & Francis and can be found at: http://www.tandfonline.com/loi/ufsh20#.VUEib2MywS

The Perfect Finance Minister: Whom to Appoint as Finance Minister to Balance the Budget?

The role and influence of the finance minister within the cabinet are discussed with increasing prominence in the recent theoretical literature on the political economy of budget deficits. It is generally assumed that the spending ministers can raise their reputation purely with new or more extensive expenditure programs, whereas solely the finance minister is interested to balance the budget. Using a dynamic panel model to study the development of public deficits in the German states between 1960 and 2009, we identify several personal characteristics of the finance ministers that significantly influence budgetary performance. Namely her professional background seems to affect budget deficits. During times of fiscal stress, our results can guide prime ministers in the nominating of finance ministers in order to assure sound budgeting

Effects of Handling and Crowding on the Stress Response and Viability of Chinook Salmon Parr and Smolts, 1984 Completion Report.

Transportation of migrating chinook salmon smolts from Snake River dams to the Columbia River estuary has not reversed a downward trend in Idaho stocks of this species that first became apparent in the late 1960s. Poor survival of transported smolts may be a consequence of physiological responses to stressful events during collection and transportation. This study was undertaken to evaluate the intensity of stress responses in transported smolts, to determine if stress responses decrease the viability of transported smolts, and to investigate ways of avoiding or mitigating stressful events during transportation. 34 refs., 58 figs., 13 tabs

Why local governments do not maximize profits: on the value added by the representative institutions of town and city governance

State and local governance, King and council model, Tax constitution, Productive theories of the state, Constitutional political economy, Colonial American history,