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The Importance of Spatiotemporal Fish Population Dynamics in Barrier Mitigation Planning

Ioannidou, Christina, O'Hanley, Jesse R. (2019) The Importance of Spatiotemporal Fish Population Dynamics in Barrier Mitigation Planning. Biological Conservation, 231 . pp. 67-76. ISSN 0006-3207. (doi:10.1016/j.biocon.2019.01.001) (KAR id:71568)

Abstract

In this study, we propose a novel framework combining spatially explicit population viability analysis and optimization for prioritizing fish passage barrier mitigation decisions. Our model aims to maximize the equilibrium population size, or alternatively minimize the extinction risk, of a target fish species

subject to a budget on the total cost of barrier mitigation. A case study involving a wild coho salmon (Oncorhynchus kisutch) population from the Tillamook basin, Oregon, USA is used to illustrate the benefits of our approach. We consider two different spawning adult dispersal patterns, river and reach level homing, as well as straying. Under density dependent population growth, we find that homing behavior type has a significant effect on barrier mitigation decisions. In particular, with reach homing, our model produces virtually the same population sizes as a more traditional barrier prioritization procedure designed to maximize accessible habitat. With river homing, however, we find that it is not necessary to remove all barriers in order to maximize equilibrium population size. Indeed, a stochastic version of our model reveals that removing all barriers actually results in a marginal increase in quasi-extinction risk. We hypothesize that this is due to a population thinning effect of barriers, resulting in a surplus of recruits in areas of low spawner density. Our findings highlights the importance of considering spatiotemporal fish population dynamics in river connectivity restoration planning. By adding greater biological realism, models such as ours can help conservation managers to more strategically allocate limited resources, resulting in both cost savings and improved population status for a focal species.

Item Type: Article
DOI/Identification number: 10.1016/j.biocon.2019.01.001
Uncontrolled keywords: river connectivity; optimization; population viability analysis; density dependence; homing; coho salmon
Subjects: H Social Sciences
Divisions: Divisions > Kent Business School - Division > Department of Analytics, Operations and Systems
Depositing User: Jesse O'Hanley
Date Deposited: 08 Jan 2019 15:38 UTC
Last Modified: 19 Sep 2023 15:03 UTC
Resource URI: https://kar.kent.ac.uk/id/eprint/71568 (The current URI for this page, for reference purposes)

University of Kent Author Information

Ioannidou, Christina.

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CReDIT Contributor Roles:

O'Hanley, Jesse R..

Creator's ORCID: https://orcid.org/0000-0003-3522-8585
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