Aquaculture and Fisheries Commons^™

Estimating Fish Diet In Lake Turkana, Kenya, Julia G. Sharapi

Student Publications

Lake Turkana, located in northern Kenya on the Ethiopian border, is the world’s largest permanent desert lake. Over 90% of its flow originates from the Omo River in Ethiopia, which causes the lake to have seasonal rises and falls in water level. The Omo River has been subject to the construction of five dams (the Gilgel Gibe dams) and several irrigation projects. These developments will impact the amount of water entering the lake, with implications for lake chemistry and productivity, littoral habitat availability, and the breeding biology of the lake’s fishes. Though ongoing upstream changes are likely to have serious …

Now Hear This! Orientation And Behavioral Responses Of Hatchling Loggerhead Sea Turtles, Caretta Caretta, To Environmental Acoustic Cues, Bethany Holtz

Celebration

Although the visual and geologic orientation cues utilized by sea turtle hatchlings during seafinding, when they move from the nest to the sea after hatching, have been well studied, the potential for auditory stimuli to act as an orientation cue has not been well explored. Over the past several decades our knowledge of the auditory capacity of sea turtles has increased greatly, yet little is known about the biological significance of this sensory ability. To investigate whether hatchlings can use ocean sounds during seafinding, we measured the behavioral responses of hatchling loggerhead sea turtles (Caretta caretta) collected from nesting beaches …

Lens On Habitat Destruction: A Photo Essay In Double Exposure, Bethany Holtz

Student Publications

Human greed and ignorance bulldoze through nature, leaving behind scarred landscapes and broken ecosystems. Within the world’s aquatic environments, human actions have irreversibly fragmented and shattered habitats of countless animals. Voiceless, these displaced animals suffer largely in silence—their stories untold and invisible. Using my lens to expose their cries, my photography uncovers the narrative of habitat destruction.

In this photo essay, I juxtapose the pristine and degraded habitats of five threatened aquatic species using double exposure techniques, a method where two disconnected images are merged to create one unified work. By balancing light, opacity, color, and transparency, I focus attention …

Seismic Surveys And Marine Turtles: An Underestimated Global Threat?, Sarah E. Nelms, Wendy Dow Piniak, Caroline R. Weir, Brendan J. Godley

Environmental Studies Faculty Publications

Seismic surveys are widely used in marine geophysical oil and gas exploration, employing airguns to produce sound-waves capable of penetrating the sea floor. In recent years, concerns have been raised over the biological impacts of this activity, particularly for marine mammals. While exploration occurs in the waters of at least fifty countries where marine turtles are present, the degree of threat posed by seismic surveys is almost entirely unknown. To investigate this issue, a mixed-methods approach involving a systematic review, policy comparison and stakeholder analysis was employed and recommendations for future research were identified. This study found that turtles have …

Recruitment Facilitation And Spatial Pattern Formation In Soft-Bottom Mussel Beds, John A. Commito, Ann E. Commito, Rutherford V. Platt, Benjamin M. Grupe, Wendy Dow Piniak, Natasha J. Gownaris, Kyle A. Reeves, Allison M. Vissichelli

Environmental Studies Faculty Publications

Mussels (Mytilus edulis) build massive, spatially complex, biogenic structures that alter the biotic and abiotic environment and provide a variety of ecosystem services. Unlike rocky shores, where mussels can attach to the primary substrate, soft sediments are unsuitable for mussel attachment. We used a simple lattice model, field sampling, and field and laboratory experiments to examine facilitation of recruitment (i.e., preferential larval, juvenile, and adult attachment to mussel biogenic structure) and its role in the development of power-law spatial patterns observed in Maine, USA, soft-bottom mussel beds. The model demonstrated that recruitment facilitation produces power-law spatial structure similar …

Phylogenetic Analysis Of Algal Symbionts Associated With Four North American Amphibian Egg Masses, Eunsoo Kim, Yuan Lin, Ryan R. Kerney, Lili Blumenberg, Cory Bishop

Biology Faculty Publications

Egg masses of the yellow-spotted salamander Ambystoma maculatum form an association with the green alga “Oophila amblystomatis” (Lambert ex Wille), which, in addition to growing within individual egg capsules, has recently been reported to invade embryonic tissues and cells. The binomial O. amblystomatis refers to the algae that occur in A. maculatum egg capsules, but it is unknown whether this population of symbionts constitutes one or several different algal taxa. Moreover, it is unknown whether egg masses across the geographic range of A. maculatum, or other amphibians, associate with one or multiple algal taxa. To address these …

The Effect Of Medetomidine On The Burying Speed Of Corbicula Fluminea, Andrew K. Schmucker

Student Publications

A new anti-fouling drug, medetomidine, was tested to determine if it reduced the burying speed of a freshwater alien-invasive bivalve species, Corbicula fluminea. Corbicula are known to damage underwater structures and must be managed with chemical paints. The burying speeds of Corbicula were measured both before and after exposure to two different concentrations of medetomidine. The burying speed of Corbicula before exposure to a 1x10^-6 M medetomidine solution was not significantly different from the burying speed after exposure (t=.55, df=21, p=.588). The burying speed of Corbicula was significantly slower after exposure to a 1x10^-5 M medetomidine solution …

Consumption Of Aquatic Plants By The West Indian Manatee, Kay Etheridge, G. B. Rathbun, J. A. Powell, H. I. Kochman

Biology Faculty Publications

Because manatees (Trichechus manatus) are large aquatic herbivores they have often been considered as potential control agents for aquatic plants. Several problems are associated with this concept, and a major one has been the gap in knowledge concerning food consumption rates of manatees. We estimated food consumption by measuring chews per unit time, chews per amount of food consumed, and time spent chewing food. Data were collected on captive manatees of various sizes and used to construct regression equations that predict consumption rates based on body size. Time budget data were obtained by radiotelemetry of free-ranging animals. Estimates of …