**3. Changing marine biodiversity through increasing presence of alien species**

Research methods used to study species caught by artisanal fishermen include interview and field surveys, which have allowed the discovery of various concerns, affecting SSF and marine biodiversity in Maltese waters.

Apart from the problems faced by SSF fishermen affected by the limited space available for fishing due to the designations for marine protected areas, aquaculture, tuna penning, swimming, bunkering zones, wrecks, SCUBA diving areas, Freeport and Port activities, there is the increasing concern of marine environmental changes affecting marine life on reefs and coastal waters in particular. Changes due to marine pollution, climate change and anthropogenic introduction of alien species. These changes have also been considered to have affected periodical blooming of gelatinous species in various Mediterranean regions, including Maltese waters, which have also procured episodes of discomfort for some SSF [47].

Alien species presence increasingly observed in the Mediterranean Sea is reported to have been caused by various factors [34, 48]. In turn the increasing number of alien species that become invasive pose serious impacts to fishermen that are faced with strange and unknown species in their catch, some of which are poisonous. Examples of these include the silver-cheeked toadfish (*Lagocephalus sceleratus)* which has expanded its presence in the Mediterranean Sea since its first record from Gökova Bay, Turkey, in 2004 [49]. The lionfish (*Pterois miles*) invasion has also been reported in the Mediterranean Sea [50], after its initial presence was reported in 1991 off Israel [51]. However, as various species entering the Mediterranean become invasive even before detailed analyses on these alien species are undertaken, little is really known about their adaptations and genetics after they spread their distribution into the Mediterranean [52]. For this reason, genetic tools were also used to study alien species

Most of the Maltese fishermen change their fishing strategies depending on the open fishing season, migratory patterns of the species and the local market's needs. Thus as they alter their operations, the fishing effort for demersal deep-water species lowers to target more economically important species such as *Thunnus thynnus*, *Xiphias gladius* and *Coryphaena hippurus*. Nonetheless, some *H. griseus* landings persist throughout the year due to by-catch from trawling activities and by a very few individual fishermen with boats <12 m who fish for demersal deep-water species all year round. The latter use bottom long-lines and alter between different

**Figure 3.** The annual landings (kg) of *Hexanchus griseus* in Malta for the years 1986 till 2016 (Department of Fisheries,

Although currently there is no direct local or EU legislation limiting landings of *H. griseus*, both Maltese legislation and the EU council regulations [14, 20] identified *H. griseus* as a species that requires monitoring and precautionary management actions to protect the species. In this scenario, it has to be noted that any protective measures have to consider that in Malta, *H. griseus* is a socio-economically important species to a small number of local small-scale fishermen who have sustainably harvested this resource for decades. Its presence is important to their livelihood especially during the winter months when this shark is caught as an alternative to other commercially important species, while throughout the year it provides a small sustained income to a handful of individual fishermen with small fishing vessels (<12 m). Moreover, given that local fishermen (except trawlers) tend to diversify fishing activities, then *H. griseus* provides another fishing alternative, sustaining a balance between other commercially important species. The current small-scale fishery of this species has benefitted from scientifically based knowledge, which guarantees the survival of the species through an early warning sign of stock depletion, while ensuring the sustainability of its fishery and the liveli-

fishing grounds targeting different species, including *H. griseus*.

hood of the fishermen involved [35, 44–46].

National Statistics).

90 Selected Studies in Biodiversity


**Table 1.** A list of the alien fish species recorded in Maltese waters whose identity was confirmed through morphological and genetic analyses.

found in Maltese waters by using DNA barcoding (**Table 1**) as a first step toward accurate identification of species followed by other molecular markers once several specimens were sampled from different parts of their distribution, as has been carried out with native species.

FAO data for the GFCM area indicates that in 2014 at least 5.7% of the marine fish landings were classified as unidentified, while several others, including some species of groupers, are classified down to high taxonomic levels such as *Epinephelus* spp. [4]. Direct exploitation has been the main cause leading to the inclusion of *Epinephelus marginatus* as an endangered species within the IUCN Red List of Threatened Species both at global [62] and at Mediterranean level [62] due to serious declines in its population. However, environmental changes in the marine habitats due to climate change, anthropogenic activities and increasing presence of alien species [34, 48, 53–60] are posing additional threats to the Serranidae species in the central Mediterranean Sea. Therefore, to ensure effective conservation measures, the genetic identity and phylogenetics of the species around the Maltese Islands were studied to compare these with similar species found elsewhere within and outside the Mediterranean region. Accurate genetic identification through the analyses of multiple genes can be used as molecular tools to assess the genetic identity and phylogenetic relationships between species, while subtle genetic differences found within each species can provide preliminary understanding of its phylogeographic distribution, thus identifying any distinct stocks or limited gene flow. Impacts of reef alien species, which may compete or prey upon local reef species, need urgent consideration and further ongoing research. The latter is necessary for both the conservation of vulnerable species and the safeguard of fish communities from environmental impacts that affect SSF as well. The results of these anthropogenic and natural studies are integrated to provide an important holistic view of how the Mediterranean region is changing in these sectors.

Safeguarding Marine Biodiversity in a Changing World: Maltese Small-Scale Fisheries and Alien…

http://dx.doi.org/10.5772/intechopen.76609

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Small-scale artisanal fisheries are in fast decline in the Maltese Islands, which reflects a symptom around the Mediterranean where both policies and environmental change are having a heavy toll on these ancient maritime traditions. However, recreational fishing vessels that are not monitored closely are in rapid increase. According to the key elements of the Strategic Plan 2011–2020, including Aichi Biodiversity Targets, Strategic Goal A—*Target 1 states that by 2020, at the latest, people are aware of the values of biodiversity and the steps they can take to conserve and use it sustainably*. Traditional small-scale fishers are the first to invoke conservation and sustainable use but need to be assisted in their adaptation to the many changes affecting their futures from climate change to closed seasons to increasingly importation of fish foods from abroad. *Target 2 states that by 2020, at the latest, biodiversity values have been integrated into national and local development and poverty reduction strategies and planning processes are being incorporated into national accounting, as appropriate and reporting systems*. Will this consider the

Strategic Goal B—*Target 6 states that by 2020, all fish and invertebrate stocks and aquatic plants are managed and harvested sustainably, legally and applying ecosystem based approaches, so that overfishing is avoided, recovery plans and measures are in place for all depleted species, fisheries have no significant adverse impacts on threatened species and vulnerable ecosystems and the impacts of fisheries on stocks, species and ecosystems are within safe ecological limits*. This relevant and ambitious target demands close collaboration between fishers, researchers and managers in order to find

**4. Concluding discussion**

poverty that is increasing among small-scale fishermen?

Alien species found in Maltese waters and constituting first records in the Mediterranean have been studied and monitored in these waters. Such studies that also involve fishermen's cooperation [53–60] furnish useful early warning signals for timely management of bioinvasions.

Among the various alien reef species caught in shallow Maltese waters and identified genetically as well as morphologically one finds: the Cocoa damselfish, *Stegastes variabilis*; the Dory snapper, *Lutjanus fulviflamma*; the African sergeant, *Abudefduf hoefleri*; the Indopacific sergeant, *Abudefduf vaigiensis* (Quoy and Gaimard, 1825) [56]; the Lowfin chub, *Kyphosus vaigiensis* (Quoy and Gaimard, 1825) [57]); the African Hind, *Cephalopholis taeniops* and the Niger Hind, *Cephalopholis nigri*; the Squirrelfish, *Holocentrus adscensionis* (Osbeck, 1765) [59]; and the Monrovia doctorfish, *Acanthurus monroviae* (Steindachner, 1876) [60]). **Figures 4** and **5** show some of the alien species caught in Maltese waters. **Table 1** shows the habitat preference of these species and the current status of these species in Maltese waters. Through ongoing research and monitoring it was possible to confirm species establishment while other potentially dangerous and invasive species such as the pufferfish and lionfish species were also spotted [61] posing particular cumulative impacts on fisheries and native reef species. The diversity of invasive species may produce diverse impacts that still need to be understood [8, 9].

**Figure 4.** Photo of the Squirrel fish, *Holocentrus adscensionis* (Osbeck, 1765) (Beryciformes: Holocentridae), first record of its presence in the Mediterranean Sea [59]. This species is a subtropical reef-associated fish native to the Atlantic Ocean and may therefore compete with native Mediterranean reef species.

**Figure 5.** Photo of the alien Niger Hind, *Cephalopholis nigri* (Perciformes: Serranidae), from Maltese coastal water [58].

FAO data for the GFCM area indicates that in 2014 at least 5.7% of the marine fish landings were classified as unidentified, while several others, including some species of groupers, are classified down to high taxonomic levels such as *Epinephelus* spp. [4]. Direct exploitation has been the main cause leading to the inclusion of *Epinephelus marginatus* as an endangered species within the IUCN Red List of Threatened Species both at global [62] and at Mediterranean level [62] due to serious declines in its population. However, environmental changes in the marine habitats due to climate change, anthropogenic activities and increasing presence of alien species [34, 48, 53–60] are posing additional threats to the Serranidae species in the central Mediterranean Sea. Therefore, to ensure effective conservation measures, the genetic identity and phylogenetics of the species around the Maltese Islands were studied to compare these with similar species found elsewhere within and outside the Mediterranean region. Accurate genetic identification through the analyses of multiple genes can be used as molecular tools to assess the genetic identity and phylogenetic relationships between species, while subtle genetic differences found within each species can provide preliminary understanding of its phylogeographic distribution, thus identifying any distinct stocks or limited gene flow.

Impacts of reef alien species, which may compete or prey upon local reef species, need urgent consideration and further ongoing research. The latter is necessary for both the conservation of vulnerable species and the safeguard of fish communities from environmental impacts that affect SSF as well. The results of these anthropogenic and natural studies are integrated to provide an important holistic view of how the Mediterranean region is changing in these sectors.
