Can jetties replace rocky shores?

Leanne Bonnici
Leanne Bonnici

The marine environment needs to be conserved because all enjoy it in summer for leisure and fishermen depend on it for their livelihood. Our rocky shores also hold a unique ecology and it must be studied as a whole to understand how a seemingly insignificant crab or limpet can affect other species we might consider more important.

Our natural environment can be likened to a puzzle having thousands of pieces. If one piece is removed or changed, it will result in a different or incomplete picture. Jetties are artificial structures, in an otherwise natural matrix of rocky shore habitat, which add a new piece to the puzzle. They are built at right angles to the shore and are much smoother than natural rock. These differences are expected to change the environment and species living there. Leanne Bonnici (supervised by Dr Joseph A. Borg and Prof. Patrick J. Schembri) studied these jetties to understand how they would affect the big picture.

Bonnici studied three sites on the northeastern coast of the Maltese Islands (Little Armier, White Tower Bay and Għajn Żejtuna). The organisms on jetties in these areas were sampled from the mediolittoral zone — that part of the shore that is regularly submerged and exposed to the air. Sampling showed that the most abundant algae were low-growing green algae (Cladophoropsis sp.), and a red alga (Jania rubens). The algae serve as a source of food and shelter to other species.

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The most common animals were crustaceans, molluscs, and polychaetes. Polychaetes are worms that possess lots of hair-like structures (chaetae). The most common polychaetes were small voracious predators a few millimetres in length. The diverse crustaceans included small cone shaped barnacles (Chthamalus spp.), which spend most of their life attached to rocks. Other abundant crustaceans included minute shrimp-like swimming animals known as amphipods (Hyale sp. and Ampithoe sp.) that are typically found amidst algae. The molluscs recorded included different species of limpets Patella spp., as well as the chiton Acanthochitona sp.; all of these are usually found attached to the substratum, although they do move to graze on algae.

Bonnici found that jetties share some species with rocky shores; however, jetties always had a lower diversity and fewer numbers of individuals living on them. Therefore one can conclude that jetties cannot replace natural rocky shores.

Keeping to the puzzle analogy, if we know how modifying a ‘piece’ of the environment changes the other pieces, it will help maintain the whole picture. This study will help better manage how jetties affect organisms and make the most out of these artificial structures.

 

This research is part of an M.Sc. in Biology at the Faculty of Science. It was partly funded by the Strategic Educational Pathways Scholarship (Malta), which is part-financed by the European Union – European Social Fund (ESF) under Operational Programme II – Cohesion Policy 2007-2013, “Empowering People for More Jobs and a Better Quality Of Life”.

Diabetes: from genes to blood

Alexandra Fiott
Alexandra Fiott

Type 2 diabetes mellitus is a disease that affects over 250 million people worldwide. Many in Malta suffer from the disease because of our high carbohydrate diet and lack of physical activity. Type 2 diabetes arises when levels of the sugar glucose remain very high in the blood. Testing normally involves frequent finger pricks to determine blood sugar levels, or otherwise a patient can take a sugary drink followed by regular urine/blood testing over 2 or more hours.

Alexandra Fiott (supervised by Prof. A. Felice) studied whether the absolute HbA1c levels (the haemoglobin fraction with sugar attached multiplied by the haemoglobin concentration) would provide a better method to describe the link between one’s genetics and diabetic condition. She attempted to reduce the frequency of the testing needed while using a relatively non-invasive test — the withdrawing of one tube of blood, while investigating the genetics of diabetes.

Haemoglobin (Hb) transports oxygen throughout the blood through red blood cells. The HbA1c forms when glucose binds to haemoglobin. This can be used as an indirect measure of average blood sugar concentrations. Measuring HbA1c levels is rapid, but unfortunately the results are influenced by factors that affect red blood cells. With around 5% of Maltese having red blood cell disorders, an alternative measurement would help reduce inaccurate results and unnecessary worry for patients. The absolute HbA1c was used for this study.

The genetics and blood profile of five different patient groups were determined using genetic and biochemical methods: adults with a normal blood profile, anaemics, beta-thalassaemics, pregnant women, and type 2 diabetics (on limited treatment). Statistical analysis did not reveal an improved link, but the absolute HbA1c did help distinguish between the different patient groups.

To improve the reliability of these results, a separate set of experiments was carried out to see whether a known Maltese variation in haemoglobin, with a prevalence of around 1.8% in the Maltese population, has an effect on the amount of sugar that binds to the haemoglobin. This variant was found not to influence the blood glucose levels and therefore the HbA1c.

Taken together these results showed that the absolute HbA1c does not improve the link between the genetics and blood profile of the patients. However, it could distinguish between different groups of patients.

 

This research was performed as part of an M.Sc. (Melit.) in Biomedical Sciences at the Faculty of Medicine and Surgery at the University of Malta.

Deep Sea Malta

Kimberly Terribile
Kimberly Terribile

The deep sea covers 70% of the Mediterranean seabed, with Malta on the boundary of the Sea’s two main biogeographical sectors. Despite its importance in detecting changes in biodiversity, research on what lives in this habitat lags behind. Kimberly Terribile (supervised by Prof. Patrick J. Schembri) characterised the marine life on the seabed in deeper waters around Malta as a first step to find out what lives far beneath our waves.

Terribile studied species by-catch samples that were caught from depths of 72 to 201m during deep sea trawls from 2009–2011. These were part of the Mediterranean International Trawl Surveys (MEDITS), which is meant to assess the state of fish stocks around the Mediterranean. Over 100 samples were analysed, which showed that light and the grain size of the sea bottom greatly influence the species that can live there. The type and number of species found were different from distributions seen in the western Mediterranean. She also mapped which species groups were found where.

Taken together, these results show that the assemblages of species in the western Mediterranean are different from those in the central and eastern areas. The knowledge of these ecosystems is essential to properly manage these areas to maintain the health of fish stocks and for the management of the marine environment around Malta.

Mapping the deep sea holds strong commercial importance. By knowing where important feeding, spawning, and nursery areas may occur, fish stocks and other commercially important species can be properly managed to maximise the catch from the Mediterranean without causing the populations to collapse.

The study attempted to start understanding the deeper seas around Malta. Fish do not exist individually, they need to breed, shelter and feed on other organisms. To maintain commercial fish you need to understand how all species affect each other. The study is a first step in maintaining our seas for tomorrow.

 

This research was performed as part of an M.Sc. (Melit.) in Biology at the Faculty of Science. This project forms part of a collaboration between the Department of Biology and the Maltese Government’s
Department of Fisheries and Aquaculture.

The Universe is Strange and Beautiful

Super dense stars shooting jets of radiation, black holes swallowing up stars, supernovae, and unexplained bursts of gamma rays. These are all examples of a ‘transient event’, an incident that lasts at most a few days. They are amongst the most powerful and mysterious phenomena in the universe, but from Earth they appear as ‘blips’ on our telescopes, making them very difficult to study.

Byron Magri (from the Astronomy, Astrophysics and Cosmology Research Programme (AACRP) and supervised by Dr Kris Zarb Adami) is shedding light on how to detect these fleeting wonders. His work is focused on fast transients that only last a few seconds.

Earth-based radio telescopes (aka antennae) are as big as they can get. The problem is that astronomers need bigger telescopes to produce higher resolution images to reveal finer details about these objects and find new discoveries. The solution is to use arrays of smaller radio antennae that are linked together. Interferometry is used to combine the data.

The technique uses enormous computing power to measure the radio waves phase delays being gathered by the individual antennae. Interferometry then overlaps and superimposes them to produce a stronger signal and an image with a much higher resolution.

For this technique to work, it must carry out all the calculations as the event is happening. The computer algorithm interpreting the data must also filter out all the noise due to the Earth’s atmosphere. To top it all off, the transient events need to be singled out.

To meet these challenges Magri used GPUs (Graphic Processing Units), which are usually used by hardcore gamers to power the most advanced graphics. The design of GPUs lends itself well to heavy numerical processing. Magri wrote an algorithm that acts as an inferometer on a GPU and he is testing it on data from the BEST-2 radio telescope array in Medicina, Italy.

Developing these algorithms is important to make future arrays larger. The next generation interferometer, the Square Kilometer Array, will have hundreds of antennae, meaning that information extraction will need to be extremely efficient and rapid. These algorithms are a keystone to maximise the potential of a €1.5 billion telescope to find more amazing phenomena in our universe.

 

This research was performed as part of an M.Phil. (Melit.) in Physics at the Faculty of Science. For more about Malta’s role in the Square Kilometre Array see pg. 14, Issue 02 of  Think magazine (http://bit.ly/SKATHINK).

Logical chemicals

Chemistry is not usually associated with logic gates, sensors, and circuits. However, a new breed of chemist — the molecular engineer — is adding a bit of chemical spice to them. Given the right tools, his/her hands can synthesize anything, from molecules that assemble into large structures to others that can display information about their environment.

Thomas Farrugia (supervised by Dr David Magri), created a molecule that could be toggled between an ON and OFF state using AND Logic. AND logic means that it needs two chemicals to switch state, adding just one chemical makes no difference. The states are easily recognised by shining UV light on the molecule since only the ON state produces blue light.

In the OFF state, the movement of electrons from two input sites prevents light being released. Stopping the electron transfer enables light release. The blue light shines when specific chemicals bind to the two input sites. The chemicals use up the electrons being transferred, letting the output of the molecule absorb UV light and shine blue light.

The two chemicals added were an acid and an iron (III) source (like what is found in rust). The acid provides hydrogen ions that bind to the nitrogen atom, whilst the iron (III) ions attack the molecule’s iron (II) atom (pictured as Fe). The molecule displays AND logic since it needs both the acid and iron (III) to turn on light emission.

The molecule was synthesised using a one step reaction and tested to determine the strength of the ON and OFF signals. Testing by fluoresence spectroscopy is essential to determine whether it would make a viable sensor, since the technique compares the strength of the ON and OFF state. The molecule will only work well if there is a large difference between the different states, since a machine needs to detect the change.

This molecule can sense the extent of acidity and iron (III) ions in a solution, and convey that information using light, which is easily measured. The molecule’s design could also be integrated into bigger and more complicated molecules so as to carry out other logical and mathematical operations using chemicals. These molecules are a step towards chemical computers.

This research was performed as part of a B.Sc. (Hons) Chemistry with Materials at the Faculty of Science.

Finding bats by listening

Sonar for navigation was implemented after the Titanic disaster in 1912. Bats have used this remarkable technique for the past 50 million years. These nocturnal animals emit ultrasonic signals and analyse the returning echoes to avoid obstacles or predators and find their prey. For humans, studying bats means long hours in the night spent tracking their movements or capturing them with nets. To avoid some of the bat research difficulties, conservation researchers identify and study bats by eavesdropping on the ultrasonic sounds they emit.

Clare Marie Mifsud (supervised by Dr Adriana Vella) has now studied bats in Malta, linking specific sound patterns to specific bat species and their behaviour. Bats can be identified using acoustic detection because they all use different frequency patterns to suit their needs. The analyses can be used for further research and conservation monitoring of local bats.

Her study encompasses 38 research survey sites spread all over the Maltese Islands. Two bat detectors (a heterodyne and a real-time expansion detector) are used simultaneously to instantly identify and analyse the species. Nine different bat species are already confirmed to inhabit the Maltese Islands till now.
Three species (Rhinolophus hipposideros, Myotis punicus, and Plecotus austriacus) were recorded a few times (2% of survey time), since they use low intensity echolocation signals. Other bat species (Hypsugo savii, Pipistrellus pipistrellus, Pipistrellus kuhlii, and Pipistrellus pygmaeus) were detected more often (92% of survey time). All Maltese bats feed on insects and are found to spend most of their time in valleys, followed by other habitats, including cliffs, woodlands, agricultural land, shrublands and urban settlements. Valley biodiversity is important for local bat survival and needs to be preserved.
Through the use of bat acoustic detection systems and signal analyses, this detailed research provides the first important set of data of its kind for all bat species detected in the Maltese Islands. This complements other bat research, which has been ongoing since 1998 by the Conservation Biology Research Group (University of Malta). They have been involved in different bat studies, including the ecology and genetics of local bat populations. These research efforts aim at reversing the trend of decreasing bat numbers. Mifsud’s research paves the way towards developing another effective long-term monitoring tool for the conservation of bats in Malta.

This research is part of an M.Sc. in Biology at the Faculty of Science. BICREF (The Biological Conservation Research Foundation) provided voluntary assistance during fieldwork. The research was partially funded by the Strategic Educational Pathways Scholarship (Malta). This Scholarship is part-financed by the European Union – European Social Fund (ESF) under Operational Programme II – Cohesion Policy 2007-2013, ‘Empowering People for More Jobs and a Better Quality Of Life’.