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This study targets the poorly described egg and larval stages of wrasses and parrotfishes that as adults inhabit coral reefs and seagrasses in the western central Atlantic. Descriptions are provided to allow laboratory identification of the egg and larval stages of these fishes. Accounts are given for 16 of the 20 species of labrid and six of the 14 species of scarids that occur here. The biological, hydrographic, and meteorological data from four oceanographic surveys of the southern Straits of Florida were analyzed to provide a synthesis of the effects of the environment on the distribution of larval fishes occupying a region that is influenced by geostrophic currents and mesoscale recirculation features. Results indicate these oceanographic phenomena play an important role in influencing the distribution of these fishes in their pelagic nursery habitat. The most striking evidence for this comes from the close association of high abundances of fish larvae with the Tortugas Gyre, a semi-permanent mesoscale eddy frequently present off the western Florida Keys. Most species were found in greatest abundance near the center of the eddy, while others were limited to offshore waters along its periphery in deeper depth strata. Older larvae occurred more frequently than younger stages. Those taxa most abundant near the center of the eddy were also more often taken as older larvae. Two hypotheses are proposed to account for larval accumulation in the center of the eddy, which are not mutually exclusive. The first is based on advection of passive larvae that are cyclonically entrained into the center of the eddy along the horizontal plane, while the second provides for a cascade of ecological effects that originate from eddy-induced upwelling in the vertical plane. Diel and ontogenetic effects were shown to be important components of the vertical distribution patterns displayed by these fishes. The vertical distribution of most species within the top 115 m of the water column was non-uniform. Mean depths of most larvae were deeper during the day than at night, with older stage larvae occurring deeper than younger stages.

The index of biotic integrity (IBI) comprises several fish-assemblage attributes, called metrics, that reflect how a site differs from least-disturbed (by anthropogenic influences) conditions. Understanding how metrics at least-disturbed sites vary across landscape classes (e.g., physiographies, ecoregions) and stream sizes helps one determine appropriate regions and stream-size ranges in which to develop and use the IBI. The IBI’s utility depends on how accurately and reliably each metric reflects disturbance. I make recommendations for developing the IBI for use in Virginia. I examined metric variation across landscape classes: physiographies, ecoregions, and drainage groups; and across stream sizes. I examined intra-region relations between metrics and disturbance measures and whether relations met conventional IBI assumptions. Taxonomic metrics (e.g., number of native minnow species) and reproductive metrics (e.g., proportion of individuals as lithophils) varied more across physiographies than across ecoregions or drainages. Trophic metrics (e.g., proportion as invertivores) varied least across landscape classes and most with stream size. For Virginia, I recommend three regions: Coastal Plain, Piedmont, and Mountain, in which to develop and use distinct versions of the IBI. In Coastal Plain, disturbance-vs-metric relations were mostly contrary to IBI assumptions. In Piedmont, trophic and tolerance metrics best reflected disturbance and met IBI assumptions; in Mountain, reproductive metrics did so. Disturbance measures accounted for about 20% of the variance in metrics, suggesting that my data incompletely represented disturbance effects on fish. Until further validation, I recommend that each regional IBI retain at least two taxonomic, two trophic, two reproductive, and one tolerance metric. / Master of Science

時間數列分析自一九七０年Box-Jenkins 發展出自我迴歸移動平均整合模式（簡稱Ａ ＲＩＭＡ（ｐ，ｄ，ｑ））建立法後，便更普遍地應用於經濟、企管、工程及物理等 相關領域上。但利用Box-Jenkins 的鑑定方法一般只對ＭＡ或ＡＲ模型有效，而對混 合的ＡＲＭＡ模型則不適用。其後陸續有統計學者提出不同的鑑定方法，但都無法有 效地決定Ｐ、ｄ、ｑ階數。 直至一九八四年以後，Tsay和Tiao兩位學者才又提出了一套有效的鑑定法則，利用擴 展的樣本自我相關函數（Extended Sample Autocorrelation Function）或正規分析 （Canonical Analysis）求出的最小正規相關係數（The Smallest Canonical Corr- elation ）做為鑑定ｐ、ｄ、ｑ的準則。這兩種方法的優點皆為可直接處理平穩或非 平穩型時間數列，而不用事先決定差分的階數，而且對混合ＡＲＩＭＡ模型亦有效。 對於有異常點（Outlier ）存在的時間數列，其可能由於某些外在的介入因素所引起 ，而ＡＲＩＭＡ模型對資料的配適是不足夠的。因此該如何發現異常點的存在及加入 合理的介入模式亦構成了模型鑑定的問題。本文除對Tsay和Tiao的方法做一說明外， 亦利用其鑑定方法對存在有異常點的時間數列做一分析，並由實證研究探討其對季節 模型的鑑定效果。

No / The roadside vegetation in some counties of north England (north and west Yorkshire) was studied to determine the community structure according to the British National Vegetation Classification (NVC) and main environmental factors influencing its composition. The data from Phytosociological survey (699 quadrats) and from the physico-chemical analyses of 233 soil samples from 35 sites were obtained. Both the classification (TWINSPAN & MATCH) and ordination programs (Canonical Correspondence Analysis) were used. The roadside vegetation is mainly dominated by few grasses (Arrhenatherum elatius, Festuca rubra, Dactylis glomerata, Lolium perenne, Poa trivialis, Elymus repens, Holcus lanatus) and their associated herbs (Cirsium arvense, Heracleum sphondylium, Urtica dioica). Five NVC Mesotrophic grassland communities (Arrhenatheretum elatioris community MG1, Lolium perenne-Cynosurus cristatus grassland MG6, Lolium perenne leys MG7, Holcus lanatus- Deschampsia cespitosa grassland MG9, Festuca rubra-Agrostis stolonifera-Potentilla anserina grassland MG11) and one Upland Festuca ovina- Agrostis capillaris-Galium saxatile grassland, U4 were identified which in general, exhibited good fit with the typical NVC units. Altitude, pH, potassium, sodium and road age were found to be the main variables affecting the roadside vegetation. By relating the floristic composition with ecological characteristics of the roadside verges, three kinds of pattern of variation are observed. The first pattern is related to regional or geographical characteristics and the second pattern of variation exists across the width of the road verges showing a zonal pattern of plant distribution. The third scale of pattern is active at the local level including micro-environmental conditions, e.g., local edaphic variables.

Optical parameters measured via absorption spectroscopy and high-resolution fluorescence spectroscopy were used to characterize dissolved organic matter (DOM) in the springshed of Kings Bay, a spring-fed estuary located on Florida's Springs Coast. Over the past 40 years, springs supplying groundwater to Kings Bay have shown an increase in nitrate concentration. The overall goal of this project was to fingerprint wells and spring sites with elevated nitrogen concentrations using CDOM optical properties and establish relationships between nutrient and optical parameters. Samples were obtained from various sites: springs, Kings Bay surface (KBS), wells, coastal waters in and at the mouth of Crystal River (Coast) and lakes and rivers (LNR), during dry and wet seasons. The relationships between the environmental parameters and traditional optical parameters which provide insight into source characteristics were analyzed. Excitation emission matrix spectroscopy (EEMS) provided information about the concentration and chemical nature of organic matter in the study area. CDOM optical properties combined with salinity clearly separated the sources of fixed nitrogen in the Bay. Northern springs with elevated dissolved inorganic nitrogen (DIN) concentration had lower salinities and showed a presence of protein peaks. CDOM concentration was negatively correlated with total nitrogen (TN) and DIN, which suggests that these are subjected to anthropogenic influences. Humic peaks dominated the composition of the southern springs. CDOM concentrations were much higher than in the northern springs and there was a positive correlation between CDOM and both TN and DIN. These findings suggest that the fixed nitrogen in the southern springs is naturally occurring organic matter and the low concentrations may partially be a result of subsurface mixing of saltwater and freshwater in the aquifer. Thus, hypothesis testing showed that there was a significant difference between northern and southern springs Hypothesis testing also showed that there is a significant and unexpected positive relationship between CDOM and salinity studying Kings Bay, which is due to the low CDOM concentration in the springs discharging fresh water. This unique dataset also determined that the intercept of the mixing line was significantly different form zero. This indicates that CDOM is present and detectable at very low concentrations. Parallel Factor Analysis (PARAFAC) was used to evaluate CDOM composition from excitation emission matrix spectra (EEMs) and five components were identified: two humic, two marine humic, and one protein-like. The marine-like components, peak M, were produced in the marine environment and in meteoric groundwater. The study found a unique groundwater marker for coastal regions. Northern Kings Bay sites were characterized by a protein-like component, which has been associated with wastewater. Additional optical and environmental parameters were used in discriminate analysis, which successfully identified the CDOM markers for both natural and anthropogenic sources of nutrients in the environment. It is vital to improve the analysis of water, nutrients, and carbon from groundwater discharge into the coastal zone. Elevated DIN concentrations in groundwater are a widespread problem in Florida and over the past 30 years many spring waters have shown an increase in DIN concentrations. Nutrient discharge into delicate coastal areas can lead to ecological concerns. Investigating CDOM and nutrient distribution together can be a beneficial tool that can help differentiate sources from riverine/lacustrine, estuarine, marine, groundwater, and sewage impacted categories.