Can the age of the tropical species be determined by otolith measurement?: a study using Pristipomoides filamentosus (Pisces: Lutjanidae) from the Mahe Plateau, Seychelles

The sagittal otoliths of bluespot jobfish (Pristipomoides flamentosus) from the Mahe Plateau, Seychelles, were examined for growth rings using light microscopy. Banding with putative annual and monthly frequency were observed. Consistent age estimates were derived from each of the two patterns. The resulting length-at-age data were use t estimate the parameters K and t sub(0), viz: K=0.33, t sub(0) = 0.16 for males and K = 0.36, t sub(0) = 0.06 for females (using von Bertalanffy plots). Possible causes of the banding are discussed

Gorgon CO2 Surface and Near-surface Monitoring

This report is a review of the current status of the various techniques used to monitor the near-surface environment above a GCS (geological CO2 storage) project, with specific reference to Barrow Island. The review covers a range of environments, broadly sub-divided into near-surface atmospheric, soil gas, groundwater and the near-shore and marine environment. For each environment the key parameters likely to be indicative of migrant CO2 (including CO2 directly) are considered. The techniques covered include geochemical, isotopic, geophysical, microbial, marine and near-surface atmospheric. For each technique what parameters are measured, the effectiveness of each, the stage of development, relative cost and footprint and some of the practicalities of implementing such a system on Barrow Island are described. Included in the report is a review of where these technologies are being deployed or researched at different GCS sites around the world. There are few commercial scale GCS projects, the majority are demonstration scale and the monitoring techniques being applied are as much for technology development as leakage detection. One of the major difficulties with a near-surface environmental monitoring system is the need to be able to demonstrate detectability of a small or non-existent signal within an inherently noisy system. There are potentially many ways to detect CO2 or parameters affected by its presence; however, they need to be coupled with a method to quantitatively distinguish them from the background environmental or anthropogenic variability. For each of the technologies reviewed, three common themes emerged. The first is that no single technology is likely to meet all of the monitoring objectives. The need for targeted, high intensity monitoring sites at high risk locations should be coupled with lower resolution, larger scale monitoring at low risk sites. There are technologies that are appropriate for each of these; small scale (centimetre to metres) continuous monitoring, such as soil gas or geochemistry and those more suited to periodic, regional scale characterisation and monitoring such as the airborne geophysical techniques (10's of kilometers). Some of the near-surface ambient techniques may be suitable for intermediate scale monitoring of several kilometers. The second theme is the need for modelling studies supported by field trials and data collection to quantify the effects and therefore the detectability of each parameter that may be affected by CO2. The modelling would be used to identify the areas of high risk or high uncertainty and form the foundation for building the monitoring system. The third theme is the need to collect baseline data at least one year prior to injection beginning. The collection of baseline data is fundamental to building the models and understanding the natural variation of the system, including emission sources. However, the collection of baseline data is a non-trivial exercise, particularly on Barrow Island. Each of the potentially suitable techniques would require further field based studies to determine their most effective instrument set-up and measurement resolution. Finally, the technology associated with GCS near-surface monitoring is evolving rapidly. Instrument sensitivity, data sampling rates, equipment deployability, deployment costs and processing/interpretation methods are undergoing rapid change. The monitoring system deployed on Barrow Island will need to be flexible and adaptable to account for changing conditions and technologies

Long-term oceanographic and ecological research in the western English Channel

Long-term research in the western English Channel, undertaken by the marine laboratories in Plymouth, is described and details of survey methods, sites, and time series given in this chapter. Major findings are summarized and their limitations outlined. Current research, with recent reestablishment and expansion of many sampling programmes, is presented, and possible future approaches are indicated. These unique long-term data sets provide an environmental baseline for predicting complex ecological responses to local, regional, and global environmental change. Between 1888 and the present, investigations have been carried out into the physical, chemical, and biological components (ranging from plankton and fish to benthic and intertidal assemblages) of the western English Channel ecosystem. The Marine Biological Association of the United Kingdom has performed the main body of these observations. More recent contributions come from the Continuous Plankton Recorder Survey, now the Sir Alister Hardy Foundation for Ocean Science, dating from 1957; the Institute for Marine Environmental Research, from 1974 to 1987; and the Plymouth Marine Laboratory, which was formed by amalgamation of the Institute for Marine Environmental Research and part of the Marine Biological Association, from 1988. Together, these contributions constitute a unique data series; one of the longest and most comprehensive samplings of environmental and marine biological variables in the world. Since the termination of many of these time series in 1987-1988 during a reorganisation of UK marine research, there has been a resurgence of interest in long-term environmental change. Many programmes have been restarted and expanded with support from several agencies. The observations span significant periods of warming (1921-1961; 1985-present) and cooling (1962-1980). During these periods of change, the abundance of key species underwent dramatic shifts. The first period of warming saw changes in zooplankton, pelagic fish, and larval fish, including the collapse of an important herring fishery. During later periods of change, shifts in species abundances have been reflected in other assemblages, such as the intertidal zone and the benthic fauna. Many of these changes appear to be related to climate, manifested as temperature changes, acting directly or indirectly. The hypothesis that climate is a forcing factor is widely supported today and has been reinforced by recent studies that show responses of marine organisms to climatic attributes such as the strength of the North Atlantic Oscillation. The long-term data also yield important insights into the effects of anthropogenic disturbances such as fisheries exploitation and pollution. Comparison of demersal fish hauls over time highlights fisheries effects not only on commercially important species but also on the entire demersal community. The effects of acute ("Torrey Canyon" oil spill) and chronic (tributyltin [TBT] antifoulants) pollution are clearly seen in the intertidal records. Significant advances in diverse scientific disciplines have been generated from research undertaken alongside the long-term data series