The occurrence of coastal swarms of the Scyphomedusa, Pelagia Noctiluca (Forskiil) around the Maltese Islands

The author wishes to acknowledge the contribution of the Maritime Section of the Task Force, Malta in the collection of data.Data on the occurrence of coastal swarms by Pelagia noctiluca around the Maltese Islands for January, February and March 1984 is presented, together with details of the characteristics of such swarms and relevant environmental parameters. The small average size of the component individuals indicates that they are representatives of recent spawning. It is suggested that such swarms reached the islands from the NW sector.peer-reviewe

The Ghadira Reserve : physico-chemical characteristics of the pool

The Ghadira Reserve is the largest saline marshland in the Maltese Islands. It is a protected bird sanctuary and a review of its development may be found in Sultana (1990) and a more detailed description of the area is given in Borg et al. (1990) This paper will present data on the physico-chemical parameters in the waters of this marsh as recorded from four fixed stations over a period of one year (May 1985 - April 1986). The purpose of this investigation was to provide information to the ecological study of the Ghadira pool (Borg et al., 1989) and thus to contribute towards the basic environmental information which is essential for the correct management of such reserved areas. The present Ghadira marsh complex consists of a central pool with a number of small artificial 'islands' (Figure 1). The pool is surrounded by a embankment and a ditch to limit public access to the area. Furthermore, the ditch was designed to collect rainwater and drain it into a freshwater reservoir constructed on the west side of the pool at the farthest side from the sea. This reservoir was to supply the central pool with enough water throughout the year and thereby to prevent its drying up during the summer months (Axell, 1980). The Ghadira marsh complex is separated from the sea (Mellieha Bay) by a road and a narrow sandy beach which together are approximately 100m wide.peer-reviewe

Ecology of the Ghadira pool macrofauna (Ghadira Nature Reserve, Maltese Islands, Central Mediterranean)

Sediment and water samples were collected quantitatively from three stations in the pool within the Ghadira Nature Reserve at monthly intervals over a period of 12 months (May 1985-April 1986). The macrofauna within these samples was sorted into species and counted to provide estimates of population density and abundance, and of their fluctuation with season. Five species dominated the samples: Ventrosia ventrosa (Gastropoda), Cerastodennaglaucum (Bivalvia),Orchestiagammarellus(Amphipoda),Lekanesphaerahookerimediterranea (Isopoda) and the larvae of an unidentified species of Chironomidae (Diptera). Other species present in lower numbers included: Truncatellasubcylindrica(Gastropoda),Ovatellamyosotis(Gastropoda), Gammarus aequicauda (Amphipoda), larvae of Sratiomys longicomis and an unidentified species of Syrphidae (Diptera), four different species of Hydrophilidae (Coleoptera), and the fish Liza ramada and Aphanius fasciatus.peer-reviewe

Organotin pollution in Malta coastal zone

The speciation of organotins in seawater, surface microlayer and sediments in the marine environment of Malta is described. Concentrations of tributyltin (TBT) in bulk seawater inside the harbours were as high as 0.3 μg Sn L‐1 but were below detection limits (5 ng Sn L‐1) in open sea, 1.6 km offshore. In sediments, TBT levels were highest for the yacht marinas and ranged between 0.03 and 1.5 ug Sn g‐1. Dibutyltin is more common in the surface microlayer than TBT. Diphenyl and monophenyltin were found infrequently in bulk seawater and in sediments. Tetrasubstituted organotins, namely, MenBu(4_n)Sn, where n = 1, 2, and 3, were found frequently in TBT‐contaminated sediments (0.1–9μg Sng‐1), in seawater and in the microlayer where concentrations as high as 140 μg Sn L‐1 (Me3BuSn) were measured. Direct environmental methylation of TBT and that of its debutylated analogues may play a significant role in the geochemical cycling of tin under certain environmental conditions.peer-reviewe

Jellyfish blooms in the Mediterranean

The temporal and spatial distributions of coastal aggregations of the scyphomedusa Pelagia noctiluca around the Maltese Islands during the period 1980 to 1986 were investigated by means of sighting reports from volunteers as well as by periodic monitoring at fixed stations both offshore and onshore. The available data indicate that the outbreaks of coastal aggregations of this species started in 1980 and reached maximum densities during 1981-1983. During the period 1984 to 1985, these occurrences decreased both in duration and population density, with coastal aggregations being more frequent during March and April. Such aggregates were characterized by large numbers of small medusae, probably of recent spawning. Sexually mature medusae as well as ephyrae were however present in coastal waters almost throughout the year for the period 1981-1982. The geographic distribution of such aggregates of jellyfish in the coastal areas indicate that they are passive accumulations, the pattern of which is largely determined by the prevalent wind direction.peer-reviewe

Major coastal engineering works : monitoring and management of environmental impacts and risks : a case study from the Central Mediterranean (Malta)

Coastal tourism and related developments of the past decades have significantly altered parts of the Mediterranean coastline. These include major coastal engineering works and alterations such as marina developments which lead not only to habitat loss but also to risks of degradation of water and sediment quality and of benthic communities. Being the smallest island-state in the region with the highest population density, Malta is an ideal case-study to assess such impacts.The paper presents data from a long-term compliance marine monitoring programmerelated to the development and operation of a major marina in Malta, involving major excavation works to develop a new marina basin able to hold 130 berths, complete with breakwater and other facilities. The monitoring programme(1996 to 2003)aimed at identifying and managing associated risks to the marine environment (including Posidonea oceanica meadows).For management purposes, a set of environmental objectives and quality standards were initially set for various water and sediment parameters and then subsequent monitoring of these parameters served as surveillance against risks of environmental deterioration. The paper provides useful information on the dynamics and trends in water and sediment quality resulting from such major coastal engineering works, and on how such trends may be related to associated changes (and possible recovery) of P. oceanica meadows.peer-reviewe

First full investigation of levels of microplastics on sandy beaches in Malta

This paper will report on the first full investigations on the level of occurrence and qualitative/quantitative profiles of microplastics, MP, (1-5mm) in a number of saudy beaches in Malta, (Central Mediterranean). Five popular beaches were investigated, including Ghadira Bay, Golden Bay, St. George's Bay, Ghajn Tuftieha Bay and Pretty Bay. Samples for all bays were collected in August 2015, while further detailed sampling was carried out for the last two bays in summer and in winter of2016. Sampling protocol was adopted from Galgani et aI., (2013). For all locations, samples were collected from strandline and then at 10m up shore at surface (top 5 cm). For Ghajn Tuffieha and Pretty Bay, samples were also collected from a 40cm depth. MP were extracted from sand through wet sieving, and then sorted and characterized according to size, colour, shape, and polymer type. Several parameters including degree of sea exposure and sand properties were reeorded. Full beach profiles for all locations are available. Identification of polymer type was carried out by means of qualitative density tests. In summer of 2015, the highest levels of MP were reported in Pretty Bay at 10.81 items/1000cm of wet sand with the lowest being in Ghajn Tuffieha, at 0.72 items/1000 cm. In general, levels ofMP in the dry season were found to be higher than those recorded in the wet season (winter), Higher MP concentration was recorded at 10 m up-shore as opposed to the strandline. Furthermore, surface sands comained a higher concentration of MP when compared with the subsurface sediments: though this was not was not the case at Pretty Bay in winter. These results are interpreted in terms of different beach profiles, beach dynamics, sand properties and potential sources of MP. The local level of occurrence of MP seems to be lower when compared to other European locations studied so far. The fact that in this study, MP below 1mm were not included in the data, as well as the lack of rivers in the Maltese isimlds, regular beach clean ups and other factors may explain this. Data on the characterisation of MP found are provided. For example, polyethylene and polypropylene were the most common polymers recorded at Gnajn Tuftleha Bay whereas polyethylene and paint fragments were the most common 'MP recorded at Pretty Bay, This investigation is a contribution to our knowledge of how levels of MP in sandy beaches may be affected by sand properties and dynamics, beach profiles and other factors.was no! the case at Pretty Bay in winter. These results are interpreted in terms of different beach profiles, beach dynamics, sand propel1ies and potential sources of MP. The local level of occurrence of MP seems to be lower when compared to other European locations studied so far. The fact that in this study, MP below Irnm were not included in the data, as well as the lack of rivers in the Maltese isimlds, regular beach clean ups and other factors may explain this. Data on the characterisation of MP found are provided. For example, polyethylene and polypropylene were the most common polymers recorded at Ghajn Tuftleha Bay whereas polyethylene and paint fragments were the most common 'MP recorded at Pretty Bay, This investigation is a contribution to our knowledge of how levels of MP in sandy beaches may be affected by sand properties and dynamics, beach profiles and other factors.peer-reviewe

State of the Environment Report for Malta 1998

All activities of Man have an impact on the local and global environment. It has become increasingly important to gauge these impacts, both because these impacts are becoming more and more significant and also because Man’s expectations have increased more than ever before in the last ten years. Moreover, the aspect of sustainability, that is whether what we are doing today to satisfy our needs will have an impact on future generations, has become an overriding concern. It is therefore important that all decisions are taken with an informed mind. For this to be possible, there must be accurate and accessible information about the state of our environment. Indeed, in signing the Convention on Access to Information, Public Participation in Decision-Making and Access to Justice in Environmental Matters in December 1998, Malta has pledged amongst other things to keep the public informed about the state of the environment. This is precisely the scope of this report, which intends to be one of a series of regular snap-shots of the state of the local environment. Such reports will facilitate a co-ordinated response to be made and eventually will enable trends to be discerned. While the report shows that there is considerable work still to be done in the environmental field, it is nevertheless a milestone towards achieving sustainable development. [preface]peer-reviewe