This work investigates, for the first time, the Pseudo-nitzschia (PN) dynamics in the western English Channel (L4) and the environmental factors impacting on domoic acid (DA) production in these waters. This is combined with laboratory studies examining key environmental factors and the multifactorial impact of multiple macronutrient and micronutrient availability on PN growth and DA production. An LC-MS method was established, optimised, and compared with ELISA for the accurate and reproducible extraction and determination of particulate and dissolved DA. The method was used to measure the seasonal variation in DA at L4 during 2009 and this was compared to PN seasonal abundance and diversity. Three groups a P. delicatissima-group, a P. seriata-group, and a P. pungens/multiseries-group were identified and were found to have different ecological distributions with the latter two groups significantly correlating with DA concentration. Macronutrients, in combination with other environmental factors, were found to influence PN populations at L4. Multifactorial laboratory culture experiments investigating the availability of nitrate, phosphate, and silicate, confirmed that the interrelatedness of all these nutrients significantly affected the growth, decline, and DA production of P. multiseries, and highlight the importance of both phosphate and silicate availability for DA production. When the impacts of both macronutrient (phosphate and silicate) and micronutrient (iron and copper) availability were investigated, limited growth and DA production was observed in P. multiseries cultures. Results revealed the complexity and interrelationship of factors affecting both PN growth and DA production. Furthermore, molecular methods were developed to elucidate the PN species present from 2009 Lugol’s-preserved L4 samples. DNA was successfully extracted and amplified from these samples which had been stored for up to 2 years. Initial sequence analysis identified the rbcL DNA marker as an informative site for future work with a number of L4 sequences closely relating to different Pseudo-nitzschia spp.

The English spoken in the United States has traditionally been divided into six dialect regions: New England, Mid-Atlantic, Southern, Midland, Northern, and Western. The acoustic properties of American English spoken in the Southern and Northern dialect regions have been the subject of intense research, but the acoustic properties of the Western dialect region have not been analyzed as thoroughly. The umbrella term, Western American English, includes the English spoken in a large geographic area that stretches from Montana, Wyoming, Colorado, and New Mexico to the Pacific coast. Research that has focused on the Western dialect has included participants from several states, which discounts the idea that smaller dialectical differences may exist within the West. This study describes several acoustic properties of American English as it is spoken in the state of Utah. Data collected from target hVd words were used to determine vowel formant frequency patterns using F1 and F2 values of monophthongal and diphthongal vowels, and calculate the vowel space area. Differences in vowel placement and vowel space area were found between the English spoken in Utah and the Northern, Southern, and Midland dialect regions. Similar to characteristics found in Western English, an analysis of the vowel productions in speakers from Utah indicated a fronted /ʊ/, as well as a near merger of /ɑ/ and /ɔ/. However, the analysis also revealed differences in Utah English when compared to the larger Western dialect region. In particular it was found that, unlike descriptions of Western English, Utah English speakers produced /æ/ with a relatively higher F1 than /ɑ/. The vowel space area of Utah English was found to be smaller than the vowel space area of Northern English, but larger than the vowel space area of Southern or Midland speakers.

A comprehensive investigation into the relationship between physical forcing and sus- pended particles in the shallow shelf region of the Western English Channel has been conducted, in order to evaluate the temporal dynamics of suspended particle populations. Measurements were taken across tidal cycles and seasons at station L4, part of the Western Channel Observatory (WCO), using the combination of a free-fall microstructure profiler and holographic imaging. Confirmation that L4 is weakly stratified is given, and that the formation of the seasonal thermocline is substantially altered by the spring-neap cy- cle. Stratification is variable and prone to periodic and partial erosion from atmospheric forcing during any point in any season. L4 undergoes moderate turbulent dissipation, principally as a result of tidal forcing. Typically, values of ε do not exceed 10−4 W kg−1 . L4 also exhibits tidal asymmetry, chiefly in response to stratification which, albeit weak, is frequently able to suppress turbulence when generated from the sea bed. The potential energy anomaly is small at L4, as expected for a weakly-stratified environment. Maxi- mum values in summer were shown to not exceed 50 J m−3 . Values of bed stress, τ0 , are rarely greater than around 0.18 N m−2 . Nonetheless, the critical erosion threshold falls below this, and is therefore smaller than that observed in similar locations around the UK. Seasonality in the amount of material resuspended from the seabed is important at L4. The presence of certain biological particles strongly influence particle size and may also determine if a given particle is lifted from the bed. Particles ≥ 200 μm are relatively rare, the site is dominated by particles smaller than this value in line with many other UK sites. Under certain conditions the theoretical maximum limit of particle size, the Kolmogorov length scale, does not hold and many examples of occasions when this threshold is exceeded are shown. This may generate important consequences in subsequent work undertaken at this site and other temperate shelf locations globally, particularly as these results indicate that maximum particle size appears to be governed less by the size of the local turbulent eddies and more by the presence of biological particles. This is another key seasonal component to particle dynamics in the Western English Channel. Phytoplankton populations are readily advected into and out of the L4 site, calling into question the current sampling strategy of the WCO to rely exclusively upon point measurements. Small increases in atmospheric forcing have the ability to rapidly disperse patches of phytoplankton, possibly to the point of cell mortality. Traditional sampling techniques for assessing zooplankton density have been shown to radically underestimate the number of animals present at L4, which will increase error estimates on current ecosystem models.