Scenarios for integrated river catchment and coastal zone management

The European Water Framework Directive requires EU Member States to introduce water quality objectives for all water bodies, including coastal waters. Measures will have to be introduced if these objectives are not met, given predictions based on current trends. In this context, the estimation of future fluxes of nutrients and contaminants in the catchment, and the evaluation of policies to improve water quality in coastal zones are an essential part of river basin management plans. This paper investigates the use of scenarios for integrated catchment/coastal zone management in the Humber Estuary in the U.K. The context of this ongoing research is a European research project which aims to assist the implementation of integrated catchment and coastal zone management by analysing the response of the coastal sea to changes in fluxes of nutrients and contaminants from the catchments. The example of the Humber illustrates how scenarios focusing on water quality improvement can provide a useful tool to investigate future fluxes and evaluate policy options for a more integrated coastal/catchment management strategy.     

The importance of micro and macro morphological variation in the adaptation of a sublittoral demosponge to current extremes

Sponges are known to show morphological acclimation in response to habitat variation. However, previous studies have concentrated on only one aspect of morphological variation, either gross morphology or spicule morphology. Cliona celata (Grant) is common in a variety of different habitats on the south-west coast of Ireland and has been investigated with respect to morphological variability on both scales. C. celata exhibited six different gross morphological body forms (ridged, burrowing, massive, massive/chimneys, encrusting, encrusting/chimneys). The body form exhibited was correlated to local environment, showing the extent of morphological adaptation in C. celata. Sponge size varied (from 548ᇟ to 2,345녹 cm²) between sites, with the largest (2,345녹 cm²) being found at the most stable site where flow rates were <5 cm^-1 (F>23.24, P<0.05). This may seem paradoxical as growth conditions were considered poor, but mortality and damage from material in suspension was reduced at low energy sites. At the spicule level, morphological variation was also present. Spicules at high energy sites were significantly longer, narrower and less numerous than at low energy sites (F>15.36, P<0.05). Previously, spicule variation has been associated with increased stiffness in hostile environments. However, longer, thinner spicules, as found in C. celata, may result in a more flexible sponge. This is the first study to show both gross morphological (macro) and spicule (micro) variation in a single species of sponge. However, this study only reinforces some of the previously produced information on both of these adaptations of sponges to varying environments. This study also illustrates how the results of single studies should not be used to draw conclusions for group level adaptation.     

High velocity fabric filtration for control of coal-fired boilers

As a follow-up to a pilot study, a full scale investigation of applying high velocity fabric filtration to coal-fired boiler fly ash control was conducted. Two filter systems were separately applied to two 60,000 lb/h coal-fired boilers. Performance evaluations conducted over the course of a year included total mass removal efficiency and fractional efficiencies. One filtration system employed Teflon felt as the filter media while the second system employed Gore-Tex, a Polytetrofluorethylene (PTFE) laminate on PTFE woven backing. During the course of the year, a limited number of glass felt and woven glass bags were introduced into the house containing Gore-Tex. As a separate option, the second system was outfitted entirely with woven glass bags. Preliminary results indicate acceptable performance at air-to-cloth ratio of 6 to 1. Future plans call for utilizing one of the baghouse systems for SO₂ removal.     

Zooplankton feeding ecology: contents of fecal pellets of the copepods Temora turbinata and T. stylifera from continental shelf and slope waters near the mouth of the Mississippi River

In-situ feeding habits of the copepods Temora turbinata and T. stylifera were investigated by scanning electron microscope examination of fecal pellets, the contents of which reflected copepod gut contents upon capture. Pellet contents were compared with assemblages of available phytoplankton in the water column at the times of zooplankton sampling. Samples were collected in continental shelf and slope waters of the Gulf of Mexico near the mouth of the Mississippi River. Both species ingested a wide size range and taxonomic array of phytoplankters, and to a lesser extent, other crustaceans. Fecal pellets contained primarily the remains of the phytoplankters that were most abundant in the water at times of collection. There was considerable overlap in the food items ingested by adult females of both copepod species, or two stages of T. turbinata copepodites. Thus, T. turbinata and T. stylifera are omnivores, but primarily opportunistic herbivores.     

Residency and depth movements of a coastal group of Atlantic cod (Gadus morhua L.)

Atlantic cod stocks are subdivided into geographically and biologically discrete populations; some being locally resident, others migratory. The reasons for the variation in migration pattern and the consequences it may have for population structuring is poorly understood. We studied a group of cod from the coastal waters of the Shetland Isles in the northern North Sea. During the spawning season, electronic tags that record depth and temperature over time were implanted into 133 individuals and the fish released within a few kilometres of where they were captured. Thirty-nine cod have been recaptured up to 608 days later, throughout the year and, in all but two cases, within 15 km of their release site. Geolocation methods based on temperature and bathymetry also suggested that the cod had a limited home range, remaining resident year-round in coastal waters. The cod were deeper during the winter and moved to shallower water in late spring and summer. They showed diel, fortnightly and monthly cycles in depth movement that varied much within and between individuals over the season. Residency and the individual variability in vertical movement may reflect a combination of locally complex depth strata, variable seabed substrate and the wide range of seasonally available prey resources.     

A Study of Plant Species Extinction in Singapore: Lessons for the Conservation of Tropical Biodiversity

The native vascular plant flora of the Republic of Singapore has suffered the extinction of 594 out of a total 2277 species. These represent local, not global, species extinctions. Coastal habitats, including mangroves, have lost 39% of their species, while inland forests have last 29%. Epiphytic species (62% loss) appear particularly prone to extinction, which is reflected in a similar disposition exhibited by the Orchidaceae. Deforestation and disturbance have been the main cause of plant species extinction in Singapore. The rich mangrove epiphyte flora has been totally exterminated, and a number of tree species are reduced to populations of a few mature individuals. Many more species continue to survive than the species-area relationship would predict given the 99.8% loss of primary forest. This is interpreted as a result of the failure of equilibrium to be achieved yet in the remnant forest fragments, even after more than a century of isolation. Singapore's secondary forests appear to accrete plant diversity very slowly, even if contiguous with primary forest areas. We conclude that remnant fragments of primary tropical forest, even of very small size, can play a major role in the conservation of tropical biodiversity. The patterns of extinction observed in Singapore indicate that coastal and estuarine sites are in greatest demand for development and therefore must be given high priority for conservation despite their somewhat lower biodiversity. Epiphyte and orchid diversity appear to be very good indicators of the degree of disturbance suffered by a habitat in the humid tropics.