The life history of the teardrop darter, Etheoctoma (Catonotus) barbouri Kuehne and Small, was intensively studied from September, 1972, through August 1973. A total of 299 teardrop darters was seined from two isolated populations in Alexander and Little Muddy Creeks, Kentucky. These darters are known only to occur in second, third or fourth order tributaries of the Green River in Kentucky and Tennessee, and normally seek protection afforded by rocky or vegetated edges of such streams. Gonosomatic ratios indicated that teardrop darters spawned from late March through late May in waters 12.5 - 15.5 C. Young females developed primary ova at a later date than did their older counterparts. Fry were first collected in late May in shallow riffles. Longer fish produced a greater number of mature eggs than did the shorter fish. Males were the predominant older fish; apparently few females survived to their second birthday. Length-frequency distributions and scale annuli readings inidcated three age groups - 0, I and II. Average standard lengths at these stages were 30, 41 and 46 mm. Darters gained the greatest percentage of weight during the second year of life. The faster-growing fish of Little Muddy Creek were shorter-lived than the slower-growing fish of Alexander Creek. The length-weight regression values of all fish, except female and non-sexed fish from Little Muddy Creek, were greater than 3.0. Coefficients of condition, lowest in the fall and highest in the spring months, indicated that slower-growing fish were slightly more plump than were faster-growing fish. Teardrop darters were carnivorous througout life. The most numerous food items ingested were cladocerans, chironomids, copepods and simullius. Chrironomid midge larvae were the most frequent food items ingested. Cannibalism did occur. Spring and winter months were periods of heaviest feeding. Alexander Creek darters were characterized by narrower ranges in number of fin spines and soft-rays, total and pored lateral line scales, and cephalic canal pores. One-half of the darters collected had "black-spot", Neascus of Crassiphiala bulboglossa, while about seven percent had internal mesentery nematodes (Contracaecum sp.), but harmful effects were not noted on the darters. Possible fish predators included the banded sculpin, grass pickerel and large creek chubs. Water snakes, snapping turtles, belted kingfishers and green herons may also have preyed on teardrop darters. Etheostoma barbouri occupied an ecological position most closely related to that of its darter associates. In conveniently shared the stream substrate with other darter species which were found most often in the deeper rocky portions of pools.

A systematic survey of the algal flora (excluding Class Bacillariophyceae) of Foster's Pond, Allen County, Kentucky, was conducted from January 29, 1970, to March 25, 1971. Physical and chemical data were taken in order to characterize the quality of the water and examine its relationships to floral composition and periodicity insofar as the level of discrimination employed permitted. A total of 119 taxa representing five divisions were identified. Twenty-five of these were previously unreported for the State of Kentucky. Members of the Division Chlorophyta, which composed 66.4% of all the identified taxa, dominated the flora throughout the year. Desmid and chlorococcalean taxa, respectively, were the most conspicuous components of this group. The second most commonly represented division was the Euglenophyta which was followed in abundance by the Chrysophyta and the Cyanophyta which were equally represented. The Division Pyrrhophyta had the fewest representatives. Floral diversity increased rather markedly from midsummer through fall and was at a minimum during winter and spring. By October, 1970, the Chlorophyta, which at this time made up 67% of the flora, was itself composed of 38% chlorococcalean taxa and 52% desmid taxa. Accompanying the floristic changes from late fall to winter was a reduction in the number of taxa collected and the appearance of several species not previously noted. These were primarily members of the Chrysophyceae, Cryptophyceae, and Xanthophyceae. Throughout the year the more prevalent phytoplankters included Volvox aureus, Dinobryon sertularia, and Ceratium hirundinella. V. aureus was favored by cool water temperatures, from 4 C to 15 C, and apparent organic enrichment of the water. The preferred temperature range (4 C to 26 C) of D. sertularia was considerably greater. There were indications that this phytoplankter was suppressed by maxima of other phytoplankters, one of which was Ceratium hirundinella. In contrast to V. aureus and D. sertularia, Ceratium hirundinella was found to be a summer form not occurring at temperatures below 15 C. The flora of the littoral zone was quite diverse. The rich variety of desmids was attributed, in part, to the relatively soft water. A period of stagnation and decomposition, as indicated by fluctuations in pH, alkalinity, dissolved oxygen and carbon dioxide content of the water, also seemed to favor the occurrence of many desmid taxa as well as euglenoids. Members of the Chlorococcales were favored by warm water temperatures. The soft water may also have been conducive to growth of these forms.

The literature on vitamins shows that the greater number of the studies made of vitamin "A" and "D" deficient diets have been confined to their efforts on the vertebrates. Only a few controlled experiments have been conducted to determine the effects of vitamin "A" and "D" deficient diets on the invertebrates. The purpose of this investigation was to determine the effects of vitamin "A" and "D" deficient diets on crayfish.

Sandy beaches are unique environments which offer billions of dollars’ worth of ecosystem services, including among others: storm protection, sediment storage and transport, habitat space for beach-dwelling and nesting species, nutrient cycling, and tourism. Management of coastal systems tends to be anthropocentric – adjusting the coastal environment to suit the needs of human development and use. However, management actions can have important consequences for the natural functioning of these systems, particularly on the species who live or breed on sandy beaches. It is crucial that future management actions balance the economic, aesthetic, and recreational value of these ecosystems to coastal communities and their ecosystem services. Sea turtles offer an excellent case study in this balance. Changes to nesting or incubation conditions from anthropogenic alterations (e.g., artificial lighting, beach renourishment, marine debris) can result in the abandonment of nesting, suffocation or drowning of the embryos, increased feminization or hyperthermia, or death from exhaustion, desiccation, or predation. Understanding how the nesting and incubation environment may change under different beach- or species management actions is critical to ensuring their appropriate use in sea turtle population recovery. This dissertation investigated how two management actions affect the nesting and reproductive output of sea turtles: 1) sea turtle nest relocation (Chapter 2) including the assessment of inundation risk (Chapters 3 and 4) and 2) Leave No Trace ordinances (Chapter 5). Nest relocation is a common approach used to reduce losses due to inundation, erosion, poaching, and other terrestrial threats; however, there are concerns that this strategy may alter the incubating environment of the developing embryos, and thus affect proper hatchling development and fitness. In Chapter 2, I examined potential differences in inundation exposure, sand temperature, moisture content, and grain size between paired original-relocated nest sites as well as hatchling production between in situ and relocated nests. The incubating environment between original-relocated pairs were comparable, though relocation offered a minimal net benefit as it decreased emergence success and did not reduce the likelihood of inundation. More nests were being moved than are necessary, indicating additional information is needed to identify high-risk nesting sites. To better identify nests at-risk of wave exposure which are suitable for relocation, a wave runup model was developed using historical beach elevation, offshore wave, and tide data (Chapter 3). Wave runup modeling proved effective at identifying washed over nesting sites (83%). The best choice of beach slope used in the assessment varied depending on whether the user was interested in presence of wash-over or the frequency of wave wash-over at a site. An updated digital elevation model (DEM) was not necessary as the time-averaged DEM performed better than, or comparable to, those using the most recent LiDAR survey. A more complete understanding of sea turtle embryonic tolerance to inundation would improve high-risk site identification. HOBO U20L-04 water level loggers were tested in situ to evaluate their potential to provide this inundation tolerance information versus existing PVC-based equipment at paired experimental sites and when deployed adjacent to nests (Chapter 4). The HOBO loggers could provide high resolution observations of inundation frequency, duration, and severity which can inform nest productivity; however, their high cost will limit the scale of their deployment. In a complementary role, the low-cost PVC-based design can be mass-produced and deployed across a wide spatial scale but at a reduced data resolution – the balance between the use of these equipment will depend on the resources of the monitoring agency and the specific research question. Sea turtle population recovery is predicated not just on our ability to reduce losses of developing embryos, but on the continued availability of suitable nesting habitat itself. Leave No Trace ordinances are increasingly being used to combat the issue of marine debris including abandoned beach equipment (Chapter 5). Nesting success and obstructed crawl frequency were compared before and after the implementation of the ordinance at control and treatment beach segments in a BACIPS design. The ordinances had mixed success – though obstructed crawls did decline after the ordinance in Gulf Shores and Orange Beach, the presence of an obstruction did not influence a turtle’s decision to nest and nesting success declined after the ordinance across the study area due to natural variation. More time and/or increased compliance may be necessary for improvements in nesting success to materialize. These management actions appeared to have only small effects on sea turtle hatchling production and population growth rates in the northern Gulf of Mexico. But as charismatic megafauna and valuable ecosystem service providers, their continued conservation based on the provision of suitable environmental conditions serves as an important example of the need to balance anthropocentric coastal zone management with ecosystem function. / A Dissertation submitted to the Department of Earth, Ocean and Atmospheric Science in partial fulfillment of the requirements for the degree of Doctor of Philosophy. / Spring Semester 2019. / March 29, 2019. / endangered species conservation, inundation, Leave No Trace, marine debris, nest relocation, sea turtle / Includes bibliographical references. / Mariana M. P. B. Fuentes, Professor Directing Dissertation; Thomas E. (Tom) Miller, University Representative; Jeffrey P. Chanton, Committee Member; Scott Burgess, Committee Member; Dean Grubbs, Committee Member.

No description available.

Graduation date: 1963

The requirement of marine bacteria for seawater in the medium for growth has been observed to reflect their need for the inorganic ions in seawater for their growth and metabolism. Of these inorganic ions, the marine bacteria so far examined in contrast to most terrestrial bacterial species have been found to possess a specific requirement for Na+ for growth. The Na+ requirement for growth has been found to reflect a requirement for the transport of nutrients in marine bacterial cells. This and other information regarding the characteristics of marine bacteria have come from the studies of only a few representatives of a very small fraction of the bacterial population in the sea, and one may well ask how far these observations made with a few species are true for marine bacteria as a group of organisms? In this thesis observations made on non-luminous marine bacteria have been extended to include some representative luminous marine bacteria. In the course of these studies some similarities and differences in the nutrition and metabolism of the two groups of organisms have been noted.

Fatty acid (FA) analysis is a powerful ecological tool for examining trophic relationships among marine organisms. Its application in benthic food webs may be limited because many benthic organisms consume a highly mixed diet, and FA metabolism of benthic invertebrates may obscure dietary markers. This thesis examines the use of FA as dietary tracers for studying the diets of benthic invertebrates and the fate of primary production in rocky subtidal food webs. In Chapter 2, I review the use of FA for studying benthic marine food webs, and suggest that field studies using FA analysis should also include data from controlled feeding experiments, gut contents, or stable isotope analysis to provide more reliable results. In Chapter 3, I compare FA composition among sea urchins fed four natural algal diets in a controlled feeding study. These sea urchins substantially modified their dietary FA but differed in their overall FA composition according to diet. In Chapter 4, I use FA to trace the invasive alga Codium fragile ssp. fragile and the native kelp Saccharina longicruris through two trophic transfers in an experimental food web. Substantial signal attenuation occurred with each trophic transfer, suggesting that FA analysis may be of limited use for tracing benthic primary producers in field studies. In Chapter 5, I use FA in conjunction with stable isotope analysis and gut contents analysis to investigate the contribution of detrital kelp to the diet of sea urchins in habitats adjacent to kelp beds. FA analysis was unable to distinguish among sea urchins at different distances from the kelp bed, but the results of all analyses indicated that the availability of kelp detritus declines with distance from the kelp bed, and that sea urchins in low-productivity habitats rely on both kelp detritus and benthic diatoms. In Chapter 6, I summarize the overall findings and suggest experimental and statistical methods to address some of the problems associated with using FA analysis to study trophic relationships in benthic food webs.

The St. Lucia Estuary, Africa’s largest estuarine lake, is currently experiencing an unprecedented crisis related to freshwater deprivation. This has resulted in a reversed salinity gradient and drastically reduced water levels. These harsh environmental conditions, combined with the limited connection with the open ocean have lead to a loss of biodiversity in the system. The dominant zooplankton taxa include the copepods Pseudodiaptomus stuhlmanni and Acartia natalensis and the mysid Mesopodopsis africana. In March 2007, the closed-mouth state was briefly interrupted by an open-mouth phase, induced by a unique combination of extreme climatic events. With the incoming seawater, previously excluded marine taxa re-entered the system, increasing its diversity significantly. Salinity and temperature have been referred to as driving forces in aquatic ecosystems. The tolerance limits of the key mysid species were, therefore, investigated. Results showed that M. africana has some of the highest recorded upper salinity and temperature tolerances for a mysid. Because of their high biomass, mysids have the potential to affect microalgal standing stocks. Their grazing dynamics (in relation to autotrophic food availability) were investigated in two contrasting environments within the estuary. Ingestion rates and subsequently population grazing impacts on the total microalgal standing stocks were higher at the Mouth than at Charters Creek. This was attributed to the harsh environmental conditions in the latter region. Despite the lower ingestion rates exhibited here, these mysids seem capable of meeting their energetic requirements from a microalgal diet alone. Stable isotope data, though, show that they also utilise a heterotrophic diet. Results of the mixed model SIAR v 4 revealed the contribution of the different carbon sources to the diet of M. africana. Most unique was this mysid’s ability to modify its diet on both short temporal and spatial scales. Resource utilization between the dominant taxa was also compared. All three taxa appear to be opportunistic feeders, capable of incorporating a number of food items in their diet. Between food partitioning, predator avoidance strategies, and their common ability to survive in highly dynamic environments, these species are capable of co-existing, and together contribute to the overall resilience so far shown by the system. / Thesis (Ph.D.)-University of KwaZulu-Natal, Westville, 2011.

During long-term studies of dolphins, the number of individuals in the population being studied are constantly monitored using the technique of photo-identification. This constant monitoring makes use of different researchers over time. Therefore, measurement of photographic quality and individual distinctiveness for photo-identification analyses was incorporated in this dissertation to provide an additional data set for analysis. Researchers with differing levels of experiences did not obtain the same information from the same photograph and were unable to reliably quantify variables of photo quality and individual distinctiveness, but experienced researchers were found to be more adept than inexperienced researchers in counting notches on the dorsal fin of bottlenose dolphins. These results highlight the necessity for researchers to be trained in photo-identification techniques prior to carrying out their study. This study theodolite tracked dolphins off Durban from June 2004 to Feb 2005 to assess habitat utilization of bottlenose dolphins (Tursiops aduncus) in the Durban bay region. Dolphins were seen in all months surveyed and throughout the survey area. Temporal distribution of dolphins was skewed with 91% of dolphins seen before midday and 98% of sightings observed in water depths less than 30m. Six behavioural categories were recorded, including: social, fast travel, slow travel, feeding, resting and milling. The most dominant behaviour exhibited by dolphins was slow travel (46%) followed by feeding (27%). Resting was not observed at all. Of the feeding behaviour 88% occurred in the southern end of the bay whereas other behaviours occurred randomly throughout the survey area. Additional theodolite tracks were conducted during experimental boat approaches (before, during and after boat approaches) to determine potential short-term reactions of dolphins to dolphin watching boats. Two speeds of approach (slow ~ < 5 km/hr and fast ~ > 40 km/hr) and two distances of approach (20m and 80 m) were tested. The bottlenose dolphin groups did not change their behaviour in response to boat approaches during any of the periods of experimentation. Short-term changes in group speed, group size and spread were not statistically significant. Dolphin groups continued with their ‘normal’ behaviour and spent the same amount of time in the bay when compared to their distribution and behaviour in the absence of the experimental boat. These findings indicate that the experimental boat did not affect the behaviour of dolphins at either a slow or fast approach and even at a close distance. This is interpreted as being as a result of habituation of the dolphins due to their residency in a busy port. This work is crucial in developing guidelines for the development of a sustainable dolphin watching industry off Durban. / Thesis (M.Sc.) - University of KwaZulu-Natal, Durban, 2008.