Effects of Seawalls and Piers on Fish Assemblages and Juvenile Salmon Feeding Behavior

Effects of Seawalls and Piers on Fish Assemblages and Juvenile Salmon Feeding Behavior

DOI: 10.1080/02755947.2014.910579

Stuart H. Munscha*, Jeffery R. Cordella, Jason D. Tofta & Erin E. Morgana

pages 814-827

Abstract

Shoreline modifications, such as seawall armoring and piers, are ubiquitous along developed waterfronts worldwide, and recent research suggests that their ecological effects are primarily negative. We utilized snorkel surveys to quantify the effects of seawalls and piers on fish in nearshore habitats of an urbanized estuary in Puget Sound, Washington. We observed 17 species of fish and 4 species of crab during April–August 2012 at sites modified by seawalls and piers and at reference beach sites with minimal anthropogenic structures. Species assemblages at modified sites were significantly different from those at reference beaches. At modified sites, fish distribution and assemblage structure varied with proximity to the shade cast by piers; overall fish abundances were reduced under piers, and the greatest abundances were observed at high tides in areas directly adjacent to piers. Juvenile Pacific salmon Oncorhynchus spp. were the dominant fish species, and piers reduced their presence and feeding, indicating that areas under piers provide less-valuable habitat to salmon species. Piers may interrupt movements of juvenile salmon when they use shallow waters along shorelines to migrate from freshwater to marine habitats, as juvenile salmon tend to avoid shade under piers, especially at high tides. Our results show that shoreline modifications can alter species assemblage structure, thus potentially creating novel combinations and abundances of species, and can reduce habitat function for species that utilize these and similar habitats elsewhere.

Received December 27, 2013; accepted March 27, 2014

Evolutionary rescue in a changing world.

Evolutionary rescue in a changing world.

Trends Ecol Evol. 2014 Jul 15;

Authors: Carlson SM, Cunningham CJ, Westley PA

Abstract
Evolutionary rescue occurs when adaptive evolutionary change restores positive growth to declining populations and prevents extinction. Here we outline the diagnostic features of evolutionary rescue and distinguish this phenomenon from demographic and genetic rescue. We then synthesize the rapidly accumulating theoretical and experimental studies of evolutionary rescue, highlighting the demographic, genetic, and extrinsic factors that affect the probability of rescue. By doing so, we clarify the factors to target through management and conservation. Additionally, we identify several putative cases of evolutionary rescue in nature, but conclude that compelling evidence remains elusive. We conclude with a horizon scan of where the field might develop, highlighting areas of potential application, and suggest areas where experimental evaluation will help to evaluate theoretical predictions.

PMID: 25038023 [PubMed - as supplied by publisher]

via pubmed: school of aquatic an… http://ift.tt/1li6na6

Dale Jacques Final Exam

Dale Jacques will be presenting his MS thesis titled: 

Describing and comparing variability of fish and macrozooplankton density at marine hydrokinetic energy sites. 

WHEN: Tuesday, July 15th at 10 AM
WHERE: FSH 203

All are welcome to attend. 

Fishing in murky waters: the administration’s secretive oceans policies come … – Fox News

Fishing in murky waters: the administration's secretive oceans policies come
Fox News
Moreover, according to Ray Hilborn, a professor in the School of Aquatic and Fishery Sciences at University of Washington and a renowned authority on global fish populations, the marine preserves embody a zoological contradiction. They are supposedly …

and more »

via “school of aquatic and fishery sciences” – Google News

Fishing in murky waters: the administration’s secretive oceans policies come … – Fox News

Fishing in murky waters: the administration's secretive oceans policies come
Fox News
Moreover, according to Ray Hilborn, a professor in the School of Aquatic and Fishery Sciences at University of Washington and a renowned authority on global fish populations, the marine preserves embody a zoological contradiction. They are supposedly …

and more »

via “school of aquatic and fishery sciences” – Google News

Histopathologic alterations associated with global gene expression due to chronic dietary TCDD exposure in juvenile zebrafish.

Related Articles

Histopathologic alterations associated with global gene expression due to chronic dietary TCDD exposure in juvenile zebrafish.

PLoS One. 2014;9(7):e100910

Authors: Liu Q, Spitsbergen JM, Cariou R, Huang CY, Jiang N, Goetz G, Hutz RJ, Tonellato PJ, Carvan MJ

Abstract
The goal of this project was to investigate the effects and possible developmental disease implication of chronic dietary TCDD exposure on global gene expression anchored to histopathologic analysis in juvenile zebrafish by functional genomic, histopathologic and analytic chemistry methods. Specifically, juvenile zebrafish were fed Biodiet starter with TCDD added at 0, 0.1, 1, 10 and 100 ppb, and fish were sampled following 0, 7, 14, 28 and 42 d after initiation of the exposure. TCDD accumulated in a dose- and time-dependent manner and 100 ppb TCDD caused TCDD accumulation in female (15.49 ppb) and male (18.04 ppb) fish at 28 d post exposure. Dietary TCDD caused multiple lesions in liver, kidney, intestine and ovary of zebrafish and functional dysregulation such as depletion of glycogen in liver, retrobulbar edema, degeneration of nasal neurosensory epithelium, underdevelopment of intestine, and diminution in the fraction of ovarian follicles containing vitellogenic oocytes. Importantly, lesions in nasal epithelium and evidence of endocrine disruption based on alternatively spliced vasa transcripts are two novel and significant results of this study. Microarray gene expression analysis comparing vehicle control to dietary TCDD revealed dysregulated genes involved in pathways associated with cardiac necrosis/cell death, cardiac fibrosis, renal necrosis/cell death and liver necrosis/cell death. These baseline toxicological effects provide evidence for the potential mechanisms of developmental dysfunctions induced by TCDD and vasa as a biomarker for ovarian developmental disruption.

PMID: 24988445 [PubMed - in process]

via pubmed: school of aquatic an… http://ift.tt/1mlPaQK

Genome-wide profiling of DNA methylation and gene expression in Crassostrea gigas male gametes.

Related Articles

Genome-wide profiling of DNA methylation and gene expression in Crassostrea gigas male gametes.

Front Physiol. 2014;5:224

Authors: Olson CE, Roberts SB

Abstract
DNA methylation patterns and functions are variable across invertebrate taxa. In order to provide a better understanding of DNA methylation in the Pacific oyster (Crassostrea gigas), we characterized the genome-wide DNA methylation profile in male gamete cells using whole-genome bisulfite sequencing. RNA-Seq analysis was performed to examine the relationship between DNA methylation and transcript expression. Methylation status of over 7.6 million CpG dinucleotides was described with a majority of methylated regions occurring among intragenic regions. Overall, 15% of the CpG dinucleotides were determined to be methylated and the mitochondrial genome lacked DNA methylation. Integrative analysis of DNA methylation and RNA-Seq data revealed a positive association between methylation status, both in gene bodies and putative promoter regions, and expression. This study provides a comprehensive characterization of the distribution of DNA methylation in the oyster male gamete tissue and suggests that DNA methylation is involved in gene regulatory activity.

PMID: 24987376 [PubMed]

via pubmed: school of aquatic an… http://ift.tt/1vMZfYb