Radiolarian flux in the Santa Barbara Basin as an index of climate variability

Annual radiolarian flux (1954-1986) extrapolated from varved Santa Barbara Basin sediments was compared to instrumental data to examine the effect of interannual climate variability. Paleo-reconstructions over large geographic areas or 10^3 years and longer typically rely on changes in species composition to signal environment or climate shifts. In the relatively short period studied, climate fluctuations were insufficient to significantly alter the assemblage, but there was considerable variability in the total flux of radiolarians. This variability, greatest on 5- to 25-year time scales, appears to be linked to regional climate variability. Total flux correlates to regional California sea surface temperature and the composite of sea level pressure over the Northern Hemisphere for years of high radiolarian flux resembles positive PNA circulation.

Some aspects on growth and condition index of Saccostrea cucullata (Born), Cerithium rubus (Desh) and Tellina angulata Gmelin from Bombay coast

Size variation, growth, condition index and spawning periodicities of three species of molluscs were studied for a period of 15 months from a polluted and a relatively clean marine habitat near Bombay, Maharashtra, India. Growth of Saccostrea cucullata was 1.2 times and of Cerithium rubus was 1.6 times higher in unpolluted habitat than the polluted water. Spawning was during premonsoon in S. cucullata, post monsoon in C. rubus and monsoon in Tellina angulata. Condition index and percentage edibility values were higher at less polluted stations.

Widening engineering horizons: Addressing the complexity of sustainable development

The complex, fragmented and diverse aspects of a sustainable development perspective are translated into an eight-point framework that defines a problem boundary larger than that traditionally adopted by civil engineers. This leads to practical questions intended to inform engineers who ask 'am I being sustainable?' during project implementation. The value of the questions is tested against a case history of a wastewater treatment project. This demonstrates the relevance of the questions to successive project delivery phases of defining the problem, choosing a solution and implementing that solution through design, construction and operation. The case history highlights that answers to several of the additional questions raised by considering this wider problem space are currently buried within government and clients' policies, regulations and standard practice; these answers may not be accessible to the professional engineer.

Some problems and issues of sustainable management of mangrove ecosystems of Tamil Nadu, India

Mangrove, a tidal wetland, is a good example of complex land and water system whose resource attributes is neither fully understood from an ecological perspective nor valued comprehensively in economic terms. With increased ecological and social perception of the functions of wetlands, the utility and relative values will increase. The perception, however, varies from society to society. It must be recognized that mangrove forests differ greatly in local conditions and in their ability to produce a wide variety of economic products. What may be highly productive strategy for one country may have little meaning to its neighbor. Therefore, it becomes essential that from among diversity of potential uses of the mangrove environment, specific uses will have to be decided, and management plan developed on site, or area specific basis. It is therefore necessary to arrive at a balance between the views of the ecologists and economists on the management of mangroves. Biological conservation should encompass resource management in the sense that integrity of the biological and physical attributes of the resource base should be sustained and man-induced management practices should not alter an ecosystem to the extent that biological production is eliminated. Sustained yield management for food, fiber and fuel would serve to sustain local fisheries while generating new economic enterprises. This requires the recognition of mangrove environment as a resource with economic value, and managed according to local conditions and national priorities.

Fish-makhana (Euryale salisb) integration: a case study of sustainable aquafarming system in north Bihar

The paper deals with a technique to synchronize two crops, fish and makhana (Euryale ferox Salisb) in a pond. In such eco-friendly integration both crops are mutually benefited. Decomposed plant parts of makhana crop form organic matter that releases nutrients in the water to enhance plankton population. Organic detritus not only acts as food for bottom dwelling fishes (mrigal and common carp) but also provides a suitable substratum for the growth of zooplankton, insect larvae, nematodes and gastropods. Fishes contribute to the control of makhana pests. Their faecal matter acts as organic manure for makhana crop. Plankton population fluctuated between 1260 u/l to 4030 u/l in the control pond and 1630 u/l to 4722 u/l in the experimental pond. During the grand growth period of makhana crop (April to July) the dissolved oxygen content fluctuated between 5.02 mg/l to 6.68 mg/l in the covered areas and 6.04 mg/l to 6.92 mg/l in uncovered areas. Makhana leaves acting as blanket barrier over the water surface brought down the D.O. content in the covered areas of the pond. Free CO sub(2) content showed wider fluctuation in the experimental pond (25.2 mg/l to 30.9 mg/l) than in the control pond (25.1 mg/l to 28.6 mg/l). This could be due to decomposition of plant parts of the presiding crop lying as debris at the pond bottom. Autochthonous supply of nutrients enhanced the content of nitrogen, phosphorous and organic carbon in the soil of experimental pond. The experimental pond covering an area of 0.40 ha yielded 852 kg fish and 200 kg pops whereas the control pond covering the same area produced 777 kg fish only. The net profit per ha came out to be Rs.1,04,700 and Rs. 66,200 in integrated and non-integrated system respectively. Owing to crop diversification, the present integrated system was found to be more viable than the non-integrated system in terms of production and net profit.

Chemical changes in skin mucin as an index of early stages of spoilage in fish

Results of a preliminary investigation on the overall chemical nature of fish skin mucin in lung fish, Clarias batrachus, with special reference to water soluble low molecular weight compounds, are presented. Changes observed during room temperature spoilage have been studied with a view to present a new approach towards the assessment of freshness in fish inspection. pH of the mucin was distinctly alkaline (8.2) and remained unchanged during spoilage. Much of the nitrogen was found to be present in the glycoprotein fraction. Free amino acids and purine bases were present in appreciable quantities in the aqueous extracts which registered a significant increase after 10 hrs. Post-mortem increase in total solids was accompanied by a slight rise in protein nitrogen which may indicate tissue breakdown. Increase in TVN was also observed to occur earlier in the outside mucin as compared to the inside muscle. Presence of free sugars or sialic acid could not be confirmed nor was there any indication of cholesterol and lipoid material as stated in earlier literature.

A statistical index of growth condition in an aquaculture experiment

A simple statistical index, for evaluating the condition of growth in an aquaculture experiment and indicating the extent of effect of any plausible rival hypothesis, is presented.

Industrialization as a key element of sustainable product-service solutions

Product-service systems are seen by many authors to offer potential for significant sustainability benefit. Manufacturing companies are said to be essential to such a change through their influence over product performance and over the use and end-of-life stages. Yet linking these stages such that the producer is incentivized to improve the performance of later stages is still a challenge. This paper argues for placing the producer at the centre of a new arrangement: by seeking to utilize the producer's knowledge of designing and the knowledge of volume production, through creation of platforms, while cooperating closely with other actors. The paper describes three case studies that have used such an approach to design and implement new food production systems. Based on 12 months of action research observations, 10 participating organizations from the cases were studied, and the implemented solutions assessed for environmental, economic and social performance. The results demonstrate a high level of sustainability benefit is achievable using platforms and partners to design product-service systems, while highlighting that changes to production arrangements are necessary but not sufficient to improve whole life-cycle environmental performance of product-service systems, and that producers need to cooperate closely with other actors to achieve the claimed benefits.

Discussion: Widening engineering horizons: Addressing the complexity of sustainable development

The following discussion is from an Institution of Civil Engineers (ICE) prestige lecture based on the original paper and delivered by the authors at the ICE in London on 24 September 2008.1 The event was chaired by Engineering Sustainability editorial panel chair, Professor Chris Rogers from Birmingham University. It was attended by an audience of 130 people as well as being watched by a similar number over a live web-cast. The web-cast can be accessed from the ICE archive for online viewing at http://scenta. interwise.com/etechb/ OnDemand/TH6509.