Economic and labour market implications of climate change on the fisheries sector of the Maltese Islands

Climate change has been predicted to have large and rapid impacts on the Mediterranean Sea. Impacts of increasing mean annual sea temperatures, more extreme climatic events and changes in oceanographic parameters will a ffect the distribution, productivity and resilience of commercially targeted stocks. This study uses data on the Maltese fi shing industry, collected through the EU fi sheries data collection system by the Government of Malta, to develop our understanding of how climate change may impact the Maltese fi sheries sector. The most important fleet segment contributing to the overall productivity of the Maltese fishing industry, both in terms of total biomass landed and total generated income, was comprised of vessels using hooks in 2009-2011. These vessels mainly used drifting surface longlines to target large pelagic species. In 2011, this fleet segment accounted for the largest number of full time employment positions, and was the most important fleet segment in terms of total investment. Available information on species targeted by this fleet segment suggests that the impact of climate change may in fact be positive. However, limited information is available on stock status as well as on the potential impacts of climate change on several important target species such as sword sh, dolphin sh and blue n tuna. In order to ensure the continued competitiveness of the Maltese fishing fleet in light of this uncertain situation, it is suggested that an emphasis is placed on ensuring that the industry is flexible and able to eff ectively market and promote new products as and when they emerge. This could be achieved by developing fi shers' skills accordingly, and placing an emphasis on diversifying activities.peer-reviewe

Governing bottom trawling in the Mediterranean Sea - a Maltese case study

A case study approach was used to investigate the effectiveness of the current legislative framework, and the implementation of management measures which govern bottom trawling in the central Mediterranean Sea. The general perception amongst key stakeholders interviewed in the Maltese Islands was that the current legal framework is sufficient, but that improvements in regional enforcement and control are required if shared stocks are to be exploited sustainably.peer-reviewe

Do giant barnacles contribute to deep-water biogenic reef formation in Maltese waters?

Deep-sea ROV surveys in the west Malta Graben allowed re-evaluation of previous work on the association of the giant barnacle, Pachylasma giganteum, with cold-water corals and other habitat-forming species, and this species’ contribution to formation of biogenic structures. While only a minor contributor to habitat architecture when anthozoans and other large sessile species are dominant, P. giganteum may become a habitat-former in the absence of competing species.peer-reviewe

Maximising MEDITS: using data collected from trawl surveys to characterise the benthic and demersal assemblages of the circalittoral and deeper waters around the Maltese Islands

Data from MEDITS trawl surveys in the waters surrounding the Maltese Islands were analysed to characterise the benthic and demersal assemblages of the central Mediterranean, which are only poorly known, hampering Maltese authorities in meeting legislative obligations. A total of 147 benthic species and 98 demersal species were identified. These formed four well-defined assemblages, whose structure and composition were related to depth. Total species richness and abundance of both demersal and benthic species decreased with depth. The most abundant structuring epibenthic species which characterised the identified assemblages were the tall sea pen Funicularia quadrangularis (present at depths of ca. 50–700 m), the red sea pen Pennatula rubra (ca. 100–450 m), the hydroids Lytocarpia myriophyllum (ca. 100–250 m) and Nemertesia sp. (ca. 100–600), the soft coral Alcyonium palmatum (ca. 100–400 m), and the anemone Actinauge richardi (ca. 100–600 m). These results illustrate how, in the absence of dedicated benthic mapping studies, MEDITS data can be used to provide preliminary information that would not otherwise be available.peer-reviewe

Compilation of an interpretation manual for marine habitats within the 25 NM Fisheries Management Zone around the Republic of Malta

Several EU Directives and regional conventions are concerned with the protection and conservation of marine habitats of special importance; a necessary prerequisite to implement such legislation are marine habitat classification systems and information on the distribution of marine habitat types. There are several habitat classification schemes in use for the description, designation and monitoring of habitats. The ‘Interpretation Manual for Marine Habitats within the 25 NM Fisheries Management Zone around the Republic of Malta’ provides an updated description of marine habitats found around the Maltese Islands, as well as a cross-referencing scheme for the different habitat classification systems. Marine habitats are listed according to bathymetric zone, going from shallow to deep water. The bathymetric zones included in the interpretation manual are: (1) mediolittoral, (2) infralittoral, (3) circalittoral, and (4) bathyal. Habitats listed in the European Nature Information System (EUNIS) database were reviewed, habitats which are present in the Maltese Islands were identified, and ‘new’ habitat categories have been included in the manual where there was no equivalent EUNIS habitat. For each habitat category presented, cross- references to the system used in connection with the Protocol for Specially Protected Areas and Biodiversity in the Mediterranean (SPABM) of the Barcelona Convention, to the Marine Strategy Framework Directive (MSFD) classification system of predominant habitat types, as well as to the marine habitats listed in Annex I of the ‘Habitats Directive’, were established. In addition a scheme to enable the assessment of the conservation status of marine habitats as required under the ‘Habitats Directive’ was drawn up by considering the habitat range, the area occupied by a habitat, habitat structure and function, and the habitat’s future prospects. Suitable indicators to assess favourable conservation status are presented for (i) sandbanks, (ii) Posidonia beds, (iii) reefs and (iv) sea caves. In addition, indicators to assess the conservation status of maerl beds are presented due to the local significance and the sensitivity of this habitat. The manual thus intends to aid in the implementation of measures for the protection of marine habitats and hence, ultimately, to ensure effective and efficient management of the marine environment under the jurisdiction of Malta up to the 25 NM boundary, in line with the relevant legislation.peer-reviewe

Refining deep-sea habitat classification schemes based on recent surveys in Maltese waters

ROV imagery is leading to the discovery of diverse deep-sea habitat types in the Malta Fisheries Management Zone (FMZ) at depths of 200 to 1000 meters. These include rocky bottoms with mixed assemblages dominated by cold-water corals and gorgonians, as well as sponges with both encrusting and erect growth habits. Vast expanses of different types of soft-bottom habitats are also present, mostly dominated by Anthozoa, Foraminifera and/or burrowing infauna. New habitat categories will need to be added to the existing habitat classification schemes for the deep Mediterranean Sea, including those of the European Nature Information System (EUNIS), and the Regional Activity Centre for Specially Protected Areas (RAC/SPA), to accommodate some of these discoveries.peer-reviewe

A preliminary survey of marine cave habitats in the Maltese Islands

The Mediterranean Sea is a hotspot for marine biodiversity. Past studies of Mediterranean marine caves have revealed the unique biocoenotic and ecological characteristics of these habitats, which are protected by European Union legislation. The Maltese Islands have an abundance of partially and fully submerged marine caves with di fferent geomorphological characteristics, yet there have been no systematic studies on these habitats and their associated species. This study is a firrst synthesis of existing information on the biotic assemblages and physical characteristics of Maltese marine caves. The work combines a review of the available information with a preliminary survey of some marine caves in Gozo, during which several species were recorded for the first time for the Maltese Islands. Characteristic species recorded from local marine caves are highlighted, including several species of red and brown algae, sessile invertebrates including bryozoans, ascidians and sponges, and mobile forms including crustaceans and fi sh. A marked zonation from the cave entrance to the inside of the caves was identifi ed: photophilic algae at the mouth of the cave are progressively replaced by more sciaphilic species, followed by a middle section dominated by sessile invertebrates, and then a completely dark inner section that is mostly devoid of sessile organisms. Several species protected by national and international legislation were found to occur.peer-reviewe

Is the endemic Maltese Top-shell Gibbula nivosa extinct?

The trochid gastropod Gibbula nivosa, endemic to the Maltese Islands, has recently only been found in two Maltese bays, where it occurred on seagrass leaves and under stones at depths of 1-4m. Intensive sampling of Cymodocea nodosa and Posidonia oceanica meadows, sediment and pebbles at depths of 2-12m, carried out in 2000 and 2002, resulted only in empty shells but no live animals, suggesting that the species is extinct from these localities where previously good populations were found. However, the occurrence of fresh shells from other Maltese sites suggests that small undiscovered populations may exist. G.nivosa is considered to be ’critically endangered’.peer-reviewe

New depth record of the precious red coral Corallium rubrum for the Mediterranean

Live colonies of the precious red coral Corallium rubrum have previously been recorded at depths of 600 -800 m in the Sicily Channel, but deep -water populations of this species remain poorly known. During a recent research expedition within the 25 nautical mile Fisheries Management Zone around the Maltese Islands, numerous colonies growing deeper than 800 m, down to depths of 1016 m were observed. These colonies were part of a diverse community of habitat -forming species of scleractinians, gorgonians and antipatharians.peer-reviewe

On the occurrence of Coronaster briareus (Echinodermata, Forcipulatida, Asteriidae) in the Mediterranean Sea

The sea star Coronaster briareus (Verrill Am J Sci (Ser III), 1882) is reported for the first time from the Mediterranean Sea. A total of 26 individuals were sighted in Maltese waters during ROV surveys made in July 2015 and June–July 2016. The identity of the species was confirmed through morphological examination of a specimen collected in June 2016. This identification is discussed in the light of inconsistencies in the published descriptions of species of Coronaster recorded from the Atlantic, and of individuals belonging to this genus recorded from the eastern Atlantic and whose coloration does not match that of C. briareus or C. volsellatus (the only species of Coronaster hitherto known from the Atlantic). The presence of numerous individuals of C. briareus in Maltese waters, recorded on two occasions a year apart over a relatively large area, indicates that there is an established population. This represents a considerable expansion of the distribution range of this species, which is mostly known from the western Atlantic. Possible reasons for its presence in Maltese waters are discussed, but the dynamics of the occurrence of C. briareus in the central Mediterranean remain unknown.peer-reviewe