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Field investigations have been carried out to study the changes of sea level-along the north coast of Kuwait Bay. Four zones have been studied in detail viz: Kathma, Ghidhai, Mudairah and Al-Bahra. The area is characterized by the existence of several terraces which lie between the Jal-Az-Zor escarpment and the coastline which may represent stages of changes in sea-level. Three techniques have been adopted to study the terraces: 1.Levelling, 2.Radiocarbon dating of shells, and 3. Sediment analysis by particle size analysis and scanning electron microscope. The results show that there are six terraces in the area. The highest levelled point for the First terrace was obtained from Ghidhai at 92.62 m. above Kuwait Datum, while the least elevation for a fragment of the lowest terrace was 5.99 metres above Kuwait Datum, at Al-Bahra the terraces, besides having a general tendency to decrease in height from west to east, also indicate local instability and warping. Although the upper terraces can be identified as conspicuous physiographic features, it has been difficult to correlate them according to their height. Radiocarbon dating of a small number of shell samples from the Third, Fourth and Fifth terraces gave a range of ages between >42,950 years BP. and 23,300+600 years BP.; no simple correlation between height and age is observable and the possibility of shell contamination cannot be excluded. The evidence as a whole suggests that these upper terraces are not younger than Pleistocene in age. Radiocarbon dating for the extreme lowest terraces gave an age range of between 4,570+70 years BP. and 3,560160 years BP. which suggests a time of formation in the Holocene. The sediment investigations confirm the existence of three depositional environments; fluvial, Aeolian and marine. The sediment analysis results together with their gemorphological character indicate that it is possible that the upper two or three terraces originated as a result of fluviatile as well as marine action and were affected by tectonic movements. The lowest terraces are likely to be of marine origin deformed by tectonic movements.

The aim of this study was to investigate the specificity of temperate dinoflagellate - anthozoan symbioses and the influence of any specificity on the percentage contribution of photosynthetically fixed carbon to the host's daily respiratory carbon budget (CZAR). The British symbiotic Anthozoa Cereus pedunculatus (Pennant) I Anthopleura ballii (Cocks), Anemonia viridis (Forskal) and Isozoanthus sulcatus (Gos3e) and the sub-tropical anthozoan Aiptasia pallida (Verrill) and their algal symbionts were investigated. The characteristics of freshly isolated and cultured symbionts were studied to determine whether the algal cells residing in each host species appeared different and how symbiont characteristics may be determined by the host environment. Horphology, division behaviour and photosynthetic pigment composition were examined using SEMO TEMO LMO TLC and HPLC respectively. The symbionts of each host species were identified as dinoflagellates of the genus Symbiodinium, even though there was an absence of a motile phase in the cell cycle of the British hosts. Differences between symbionts of different host species and conspecific hosts were evident with respect to thylakoid arrangement, cell size and cell division rate, and possibly pigment concentrations. Host determined phenotypic plasticity was observed with respect to the absence of a "pellicle". Host-symbiont recognition and specificity were investigated - by reinfecting aposymbiotic C. _pedunculatus with symbionts from different host species and measuring the density and biomass of symbionts at different time intervals. The presence of different strains or species of Symbiodinium was evident, with recognition of these different symbionts being predominantly post-endocytotic. 'Homologous' symbionts were the most 'successful' at repopulating C. pedunculatus. After 9 months, the population densities and biomasses, and division rates of the different 'strains' Of 3ymbionts were the same, suggesting a greater symbiotic integration with 'heterologous, 'strains' with time. The reflection of specificity by the photosynthetic fixation of carbon in vivo was measured using an 02 electrode. 1110mologous, symbiontW photosynthesized at a greater rate than 'heterologous' symbionts in vivo, despite the higher photosynthetic rates of some of these 'heterologous' symbionts in their original hosts. Photosynthate translocation by symbionts in response to different host environments was investigated using in vivo and in vitro 14C labelling and the 'growth rate method'. The percentage translocation was host-symbiont specific and appeared to be controlled by different mechanisms in different host species and conspecific hosts from different locations. The CZAR in 'natural' and reestablished symbioses was calculated. Values ranged from 25.7 to 112.2 % in the 'natural' symbi T9 es and 58.1 to 76.7 % in the reestablished symbioses when measured using C. When measured using the 'growth rate method' values were 73.2 to 188.4 % and 88.3 to 146.5 % respectively. The CZAR in the reestablished symbioses and consequently their ability to survive autotrophically reflected the specific host-symbiont relationship. Symbiosis specificity and the reduced availability of carbon to host growth and reproduction in 'heterologous' symbioses may limit 'novel' symbioses in the field.

The effect of dense accumulations of macroalgae on the mudflat invertebrate populations, was investigated in Newburgh South Quay. In order to partition the effects of the physical presence of weed and the consequent anoxic conditions of the sediment, the distribution of macro- and meiofauna was examined within a range of redox potential (Eh) and weed cover. No obvious trend was found for any species within the gradient of Eh. However, the number of individuals of <i>Capitella, Tubificoides</i> and <i>Pygospio</i> were significantly more abundant under weed cover, whereas <i>Corophium</i> disappeared almost completely in areas covered by weed. The relationship between <i>Corophium</i> burrows and depth of the chemocline (defined here as the line of colour change dividing the oxic from the anoxic zones of the sediment), was investigated by means of a photographic survey of sediment profiles. The depth of the chemocline was found to be closely associated with the bioturbational processes of <i>Corophium</i>, considered here only as the number and depth of its burrows. To demonstrate that <i>Corophium</i> is a significant bioturbator, and through bioturbation it might affect the invertebrate mudflat community, field and laboratory experiments were carried out, where the densities of <i>Corophium</i> were manipulated. The field experiment showed an increase in the organic matter of the sediment in the treatment with high density of <i>Corophium</i>; also, a decrease in the number of young <i>Hydrobia</i> was found in the same treatment. This field experiment revealed an adult-recruit interaction in <i>Corophium</i>. In the laboratory experiment, <i>Corophium</i> showed a significant increase in the redox potential, and organic matter of the sediment. There was also, an increased percentage of nematodes in deeper sections of the sediment in the treatment with high density of <i>Corophium</i>. This might be associated with a greater availability of oxygen near the burrows, or to an enhancement of the bacterial population upon which nematodes feed. Following the indications that <i>Corophium</i> by bioturbation can affect the depth of the chemocline, redox potential and distribution of nematodes with depth, its potential in the recovery of organically polluted sediments was investigated. Field and laboratory experiments were carried out in which <i>Corophium</i> was added to almost azoic and grossly enriched mud. In the laboratory experiment the chemocline was located significantly deeper in the treatment with <i>Corophium</i>, and in the field, numbers of nematodes, <i>Manayunkia</i> (and possibly <i>Pygospio</i>) increased in the treatment with <i>Corophium</i>. This field experiment demonstrated again an adult-recruit interaction in <i>Corophium</i>. It was concluded that the increase in areas covered by weed could lead eventually to the disappearance from the estuary of <i>Corophium</i>, which is the major prey item of many of the shorebirds and fish. <i>Corophium</i> is also an important sediment bioturbator and probably plays a significant role in the recovery of organically polluted sediments.

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