Biology symposium

Every year, the University Biology Symposium presents a kaleidoscope of environmental research conducted by Department of Biology graduates over the past few years.

The 16th edition, which was held yesterday at the University's John Borg Hall, featured no less than 20 undergraduate (B.Sc.) and two postgraduate (M.Sc.) projects in different areas.

The project by Ruth Debrincat Beck focused on the population of Tetraclinis articulata (the Sandarac Gum Tree - Malta's national tree) at Wied il-Mizieb, which was originally (and is still largely) a natural enclave, since most of the 202 trees on site were not planted by man; she identified dumping of construction waste and spread of alien species as the main threats.

The plants found at a highly-disturbed tributary of the Wied l-Għasel valley system - Wied l-Arkata - were studied by Danika Camilleri, who reported that the transient wetland habitat formed during the wet season supports 61 floral species. However, no orchid and other species characteristic of low levels of disturbance were identified, probably due to extensive human disturbance.

The marine ecology research projects featured a study by Petra Paula Zammit on the fouling assemblages on marker buoys at Il-Qajjenza, Birzebbuġa. Many ships pass through the site, making it a prime target for the introduction of alien (non-indigenous) species; the study recorded one sponge species in Maltese waters for the first time when a live specimen was collected from just below sea level.

Patrick Vella's Masters degree research was on the icthyofauna (fish assemblages) at experimental artificial reefs made of concrete and Globigerina limestone (ġebla tal-franka) off St Julian's Bay. He reported a low diversity of fish fauna before the artificial reef sites were set up, which increased in a relatively short time once they were deployed. The study showed that, within less than a year, several fish species that are typical of rocky bottoms were using the reefs as recruitment and nursery sites.

There were promising research projects in the rapidly expanding area of biotechnology.

Lara Chircop studied the potential of using two species of woodlice associated with natural leaf litter as decomposers to improve the quality of compost originating from spent mushroom growth material.

Rachel Cremona studied the in-vitro apoptotic bioactivity of essential oils extracted from a native South African ornamental plant, Plectranthus neochilus while Marilyn Tanti assessed the same potential of essential oils extracted from Ficus macrophylla and Ficus carica (Fig trees). Interestingly, both students found that extracts from the plant inhibit the germination of both lettuce and radish seeds, an example of allelopathy, in which species seek to hinder other competing species through chemical secretions.

In addition, the Ficus extracts also inhibited or were even cytototoxic to cancer cells line grown in the laboratory.

George Galea tested the in-vitro antimicrobial potential of essential oils extracted from Thymbra capitata (Mediterranean Thyme) and Mentha pulegium, while Therese Fiorini analysed the in-vitro anti-fungal bioactivity potential of extracts from different plant species of the Cupressaceae family, namely Cupressus sempervirens (Cypress) and Tetraclinis articulata (Sandarac Gum Tree). The results showed that such extracts were stronger than anti-fungal chemicals, another example of allelopathy.

Charlene Apap took samples of the Top-shell Osilinus turbinata from different shores around the Maltese islands and studied their genetic structure using molecular electrophoresis techniques, finding a high degree of homogeneity between them.

Local aquaculture research was recently buoyed by the success story involving cultivation of Amberjack (Seriola dumerili). Its fast growth rate, acceptance of an artificial feeding regime and low mortality in captivity, coupled with a high commercial value, make it an ideal species for intensive farming. Joanne Attard focused her Masters project on specific conditions for the cultivation of the species. However, the proliferation of fish diseases in the aquaculture industry is of major concern and Maria-Liza Scicluna studied aspects of the pathogenicity of the bacterium Vibrio anguillarum on one of the most commonly fish-farmed species - Spaurus aurata (Gilthead Seabream).

TEX-OE is a natural active extract from the epicarp of the prickly pear (Opuntia ficus-indica) that allows cells to respond to repeated stress without experiencing exhaustion. 'Algal Booster', a product based on this extract, significantly improves the uptake and fixation of calcium from a normal diet. Matthew Vella assessed its potential in shrimp cultivated in Ecuador, with encouraging results.

Bernice Abdilla studied the environmental impact of religious feasts in our islands. She found that street light decorations during feasts increase energy consumption by six KWh per day, and that, apart from the sound levels impact, fireworks may be adding approximately nine mg/m2 of copper and two mg/m2 of lead to the soil for up to 50m away from where fireworks are launched.

Cecilia Fenech assessed the impact of the Magħtab landfill on the nearshore marine environment along the Baħar ic-Caghaq coastline. She monitored the water for its temperature, salinity, dissolved oxygen, turbidity, chlorophyll a, reactive nitrates, phosphates and faecal coliform concentrations, the sediment for four heavy metals (cadmium, copper, lead and zinc), petroleum hydrocarbons and its total organic carbon levels.

Nicholas Flores Martin investigated the quantity and quality of litter produced by beach users at St George's Bay and St Thomas' Bay. He focused on beach management, analysed the effect weather conditions had on the influx of litter in local bays, and conducted a preliminary study on the presence of microplastics on local sandy beaches.

Alison Gauci evaluated the impact of Portomaso yacht marina on sea water quality and sediment. The bottom line of the research is that local yacht marina operators should be encouraged to register with the EU's Environmental Management and Auditing Scheme (EMAS).

Liane Mercieca studied the quality of the marine environment at Marsascala, which bears the brunt of sewage pollution and agricultural runoff, among other impacts, although the situation has improved slightly over the past few years.

Christabel Abela assessed macrofaunal biodiversity in a marine area off the south-eastern coast of Malta, in the vicinity of St Thomas Bay, while Danielle Calenti used visual censuses and photography to assess marine biodiversity at Wied iż-Żurrieq in terms of species, their abundance and variation with depth.

Marco Calleja studied the presence of the pygmy white-toothed shrew, vagrant hedgehog, weasel and wild rabbit at the Għadira sanctuary, using various sampling techniques, including line transects, repeated transects, point surveys and live trapping.