3-7 September 2018
Audimax | Kiel University
Europe/Berlin timezone

Simulating fish population responses to coastal hypoxia: movement behavior and the tradeoff between more oxygen and less food

3 Sep 2018, 17:30
15m
Audimax-Hörsaal-C (Kiel University)

Audimax-Hörsaal-C

Kiel University

166
Oral 02 Ecosystem Impacts 02 Ecosystem Impacts

Speaker

Kenneth Rose (University of Maryland Center for Environmental Science)

Description

The Gulf of Mexico experiences a large hypoxic area in the summer from nutrient loadings that originate from activities in the watershed. We are developing individual-based population models of croaker, menhaden, and shrimp to analyze how hypoxia effects on reproduction, growth, mortality, and movement of individuals leads to population-level responses. These population models are the last step in a series of coupled models: DLEM (nutrient delivery from watershed to coast) to Delft3D (diversions for restoration) to FVCOM (3-D physics) to WASP (water quality) to fish population model. The population models follow the hourly growth, mortality, reproduction, and movement of individuals within the 3-D FVCOM spatial grid. Currents, temperature, salinity, dissolved oxygen, and chlorophyll-a concentrations generated by the FVCOM-WASP models are used as inputs to the population models. Hypoxia effects were imposed using laboratory-based relationships that convert exposure to dissolved oxygen concentrations to reductions in growth, fecundity, and survival. We used 50-year simulations under present-day and reduced nutrient loadings (e.g., implementation of best management practices in watershed) to quantify the tradeoff of reduced nutrients resulting in higher oxygen but also potentially less food. Because of the uncertainties of the linkage of nutrient loadings to fish food, several alternative assumptions were simulated ranging from no effects on food to a direct reduction proportion to the lowered chlorophyll concentrations. We also simulated fish population responses under several assumptions of individual fish avoidance behavior, which affects their exposure to low dissolved oxygen concentrations and subsequent effects of hypoxia on mortality, growth, and reproduction. We illustrate the tradeoff between more oxygen and less food and the effects of avoidance behavior using the coupled modeling approach configured for croaker.

Email Address krose@umces.edu
Affiliation University of Maryland Center for Environmental Science
Position Professor
Are you a SFB 754 / Future Ocean member? No

Primary authors

Kenneth Rose (University of Maryland Center for Environmental Science) Dubravko Justic (Louisiana State University) Haosheng Huang (Louisiana State University) Kevin Craig (National Marine Fisheries Service, NOAA) Klaus Huebert (University of Maryland Center for Environmental Science) Elizabeth LaBone (Louisiana State University) Ehab Meselhe (The Water Institute of the Gulf) Jia Yang (Auburn University) Hoonshin Jung (The Water Institute of the Gulf) Zuo Xue (Louisiana State University) Hanqin Tian (Auburn University)

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