Life Sciences Commons^™

The Fine-Scale Habitat Use Of Risso’S Dolphins Off Bardsey Island, Cardigan Bay (Uk), Marijke N. De Boer, Sonja Eisfeld, Mark P. Simmonds

Mark P. Simmonds, OBE

The main objectives of this study were (1) to estimate the population size of Risso’s dolphins off Bardsey Island using mark-recapture techniques (De Boer et al., 2013); and (2) to study habitat-use in relation to fine-scale oceanographic features. This work provides preliminary information on the habitat-use of Risso’s dolphins and will benefit future studies, along with the development of effective conservation measures for this species throughout the region.

Photo-Identification Methods Reveal Seasonal And Long-Term Site-Fidelity Of Risso’S Dolphins (Grampus Griseus) In Shallow Waters (Cardigan Bay, Wales), Marijke N. De Boer, Josephine Clark, Mardik F. Leopold, Mark P. Simmonds, Peter J.H. Reijnders

Mark P. Simmonds, OBE

A photo-identification study on Risso’s dolphins was carried out off Bardsey Island in Wales (July to September, 1997-2007). Their local abundance was estimated using two different analytical techniques: 1) mark-recapture of well-marked dolphins using a “closed-population” model; and 2) a census technique based on the total number of iden-tified individual dolphins sighted over the study period. The mark-recapture estimates of 121 (left sides; 64 - 178, 95% CI; CV 0.24) and 145 dolphins (right sides; 78 - 213, 95% CI; CV 0.24) closely matched the census technique estimates (population size of 90 - 151). It was found that the dolphins …

Interactions Between Short-Beaked Common Dolphin (Delphinus Delphis) And The Winter Pelagic Pair-Trawl Fishery Ff Southwest England (Uk), Marijke N. De Boer, James T. Saulino, Mardik F. Leopold, Peter J.H. Reijnders, Mark P. Simmonds

Mark P. Simmonds, OBE

During offshore and onshore studies (2004 to 2009), the interactions between pair-trawls and short-beaked common dolphins (Delphinus delphis) were studied to better understand the impact of bycatch. A ‘hotspot’ area where pair-trawls overlapped with high dolphin abundance was identified. We made comparisons between boat-based data collected in absence and presence of pair-trawlers. The relative abundance and group-size of dolphins was significantly higher in the presence of pair-trawlers. Dolphins were observed associating with towing and hauling procedures. Significantly, more carcasses occurred in areas with hauling-activity than those without. Body-temperatures obtained from carcasses found near operating pair-trawlers indicated that bycatch mostly occurred …

Spatiotemporal Variation In Flow-Dependent Recruitment Of Long-Lived Riverine Fish: Model Development And Evaluation, Daisuke Goto, Martin J. Hamel, Jeremy J. Hammen, Mathew L. Rugg, Mark A. Pegg, Valery E. Forbes

School of Biological Sciences: Faculty Publications

Abstract Natural flow regimes can play a major role as an overarching ecosystem driver in reproduction and recruitment of riverine fishes. Human needs for freshwater however have altered hydrology of many riverine systems worldwide, threatening fish population sustainability. To understand and predict how spatiotemporal dynamics of flow regimes influence reproductive and recruitment variability, and ultimately population sustainability of shovelnose sturgeon (Scaphirhynchus platorynchus), we develop a spatially explicit (1D) individual-based population model that mechanistically (via energetics-based processes) simulates daily activities (dispersal, spawning, foraging, growth, and survival). With field observations of sturgeon and habitat conditions in a major tributary of …

The Neotropical Genus Austrolebias: An Emerging Model Of Annual Killifishes, Nibia Berois, María J. Arezo, Rafael O. De Sá

Biology Faculty Publications

Annual fishes are found in both Africa and South America occupying ephemeral ponds that dried seasonally. Neotropical annual fishes are members of the family Rivulidae that consist of both annual and non-annual fishes. Annual species are characterized by a prolonged embryonic development and a relatively short adult life.

Males and females show striking sexual dimorphisms, complex courtship, and mating behaviors. The prolonged embryonic stage has several traits including embryos that are resistant to desiccation and undergo up to three reversible developmental arrests until hatching. These unique developmental adaptations are closely related to the annual fish life cycle and are the …

Systematics And Biogeography Of The Australian Burrowing Freshwater Crayfish Genus Engaewa Riekk (Decapoda: Parastacidae), Quinton Burnham

Theses: Doctorates and Masters

The overall aim of this study was to explore the systematics and biogeographic patterns of the freshwater crayfish genus Engaewa Riek, a strongly burrowing freshwater crayfish restricted to the coastal corner of south-western Australia (SWA). The genus Engaewa is a Gondwanan relict with great potential as a marker of historical processes, due to its high habitat specificity and low dispersal ability. This study comprises an extensive taxonomic and phylogenetic revision of the genus Engaewa (using both molecular and morphological data), a detailed study of its distribution and uses the knowledge gained to explore biogeographic patterns in the biodiversity hotspot of …