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Animal Sciences Commons

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Articles 1 - 4 of 4

Full-Text Articles in Animal Sciences

A Hemimysis Driven Novel Ecosystem At A Modified Boulder Breakwall, Eric John Geisthardt Aug 2017

A Hemimysis Driven Novel Ecosystem At A Modified Boulder Breakwall, Eric John Geisthardt

Theses and Dissertations

The US Army Corps of Engineers (USACE) is mandated to maintain and repair aging breakwall structures in all commercial ports on the Great Lakes. In May of 2014, the construction of Milwaukee Harbor USACE “green” breakwall (GBW) reconciliation created complex rocky aquatic habitat by depositing cobble-sized stone as a veneer over standard 6-10 ton boulders, thus creating “control” (boulder) and “treatment” (cobble) habitats. The breakwall is home to a prolific population of Hemimysis anomala, the introduced Ponto-Caspian mysid, which is significantly more abundant on cobble versus boulders (p<0.05, using a novel trap for Hemimysis). Fish and forage communities were sampled in 2015 and 2016 using a combination of experimental and micromesh gill nets, night scuba diving surveys, and a novel Hemimysis trap. This nearshore lithophilic mysid appears to provide a significant new seasonal food resource in the Milwaukee Harbor for pelagic prey fishes during inshore spawning migrations and upwelling events. Alewife (Alosa pseudoharengus) and rainbow smelt (Osmerus mordax) fed heavily on Hemimysis with some individuals consuming hundreds of mysids. Night scuba diving surveys and gill netting confirmed that rainbow smelt preferred to forage on the cobble section (p<0.05), and also consumed more Hemimysis there than they did at the control breakwall site (p<0.05). Hemimysis were also the primary food item consumed by nearshore game fishes such as YOY yellow perch (Perca flavescens), YOY largemouth bass (Micropterus salmoides), and juvenile rock bass (Ambloplites rupestris) caught at the breakwall. This study provides the first documented evidence that where abundant in the Laurentian Great Lakes, Hemimysis do have the ability to significantly impact local food webs and drive the feeding ecology of both pelagic transient and nearshore resident fishes.


Life History Of The Non-Native Invasive Red Lionfish (Pterois Volitans) In The Northern Gulf Of Mexico, Alexander Q. Fogg May 2017

Life History Of The Non-Native Invasive Red Lionfish (Pterois Volitans) In The Northern Gulf Of Mexico, Alexander Q. Fogg

Master's Theses

Invasive Red Lionfish (Pterois volitans) were first detected in the northern Gulf of Mexico (nGOM) in 2010 and since then their numbers have increased dramatically. From 2010 to 2015, more than 15,000 Red Lionfish were collected opportunistically from the nGOM for this study. Length and weight relationships differed significantly among ecoregions by sex and there was clear sexual dimorphism in size with males being larger and heavier. Red Lionfish age ranged from 0-4.5 years old and males achieved greater growth rate (K) and asymptotic maximum lengths (Linf) compared to females and these parameters were also different …


Perception Of The Horizon Predicts Bird Abundance Better Than Habitat Patch Size In A Tidal Marsh Species Of Conservation Concern, Hallie Marshall May 2017

Perception Of The Horizon Predicts Bird Abundance Better Than Habitat Patch Size In A Tidal Marsh Species Of Conservation Concern, Hallie Marshall

Honors College

The Saltmarsh Sparrow (Ammodramus caudacutus) is a tidal marsh bird species facing rapid population decline throughout its range. A major cause of this decline is degradation and loss of breeding habitat, and thus there is a need to preserve coastal marshes in the northeastern United States. To do so requires an understanding of the habitat features that support robust populations. Previous studies have shown increases in Saltmarsh Sparrow abundance with marsh size increases. In other grassland bird species, habitat patches with low horizons are preferred to those with tall objects (e.g., trees, telephone poles, wind turbines). This study tests how …


Examining Movement And Habitat Selection Of Everglades Fishes In Response To Seasonal Water Levels, Gregory J. Hill Mar 2017

Examining Movement And Habitat Selection Of Everglades Fishes In Response To Seasonal Water Levels, Gregory J. Hill

FIU Electronic Theses and Dissertations

Fish distribution patterns and seasonal habitat use play a key role in the food web dynamics of aquatic ecosystems, including the Florida Everglades. In this study I examined the fine scale habitat shifts and movements of spotted sunfish, Lepomis punctatus across varying seasons and hydrologic conditions using in-situ field enclosures and Passive Integrated Transponder (PIT) systems. Data on fish use of three dominant Everglades marsh habitats and activity level were recorded continuously from January to August, 2015. Fish were more active and had the highest use of higher elevation habitats when water levels rose during an experimental reversal in mid-April. …